CN112423716A

CN112423716A - Odor-controlling absorbent materials and absorbent articles, and related methods of use and methods of manufacture

Info

Publication number: CN112423716A
Application number: CN201880095602.6A
Authority: CN
Inventors: 玛丽·弗吉尼亚·斯库菲尔德; 休·韦斯特
Original assignee: International Paper Co
Current assignee: International Paper Co
Priority date: 2018-05-25
Filing date: 2018-05-25
Publication date: 2021-02-26
Also published as: EP3801425A1; JP2021525641A; JP2024028728A; BR112020024065A2; WO2019226179A1; CO2020015224A2; CN116510057A

Abstract

Absorbent materials configured to deplete Trimethylamine (TMA), absorbent articles made therefrom, related methods of use, methods of measuring a reduction in free TMA, and related methods of making absorbent articles are described.

Description

Odor-controlling absorbent materials and absorbent articles, and related methods of use and methods of manufacture

Background

Trimethylamine (TMA) is a chemical substance that has a strong fishy smell even at low concentrations, which can cause the fishy smell symptoms of bacterial vaginosis.

During and after menstruation, the pH of the vaginal environment rises quite often. Vaginal pH is typically 4-4.5; however, during menstruation, the vaginal pH can increase to 6.6. This increase in pH may promote anaerobic bacterial overgrowth, sometimes resulting in an increase in the amount of TMA released from the more alkaline vaginal environment.

Feminine hygiene products, such as sanitary napkins, are products that are commonly used to absorb menstrual fluid, blotches, and urinary incontinence leakage. Since the fluids absorbed by these products (e.g., fluids containing TMA) may be malodorous, close to the body with minimal airflow, and worn for several hours, the malodors may accumulate in these products. Thus, TMA is a highly interesting chemical for odor control of feminine hygiene products.

Currently, absorbent hygiene products that are being promoted for odor control are achieved using perfumes, antimicrobial properties, activated carbon, or "odor lock" technology. However, conventional absorbent hygiene products do not specifically address the malodors associated with TMAs, for example by reducing TMAs.

TMA is also associated with meat products, particularly fish products. Bacterial and fish enzymes convert TMA oxides present in fish to TMA. The absorbent pad included in the meat package may absorb meat juices and other liquids associated with the meat product. However, conventional absorbent pads for meat packaging do not specifically reduce TMA or otherwise reduce TMA malodor associated with meat products.

Thus, there is a long-felt need for absorbent products that absorb liquids and reduce TMA, thereby reducing TMA malodor. The present disclosure seeks to meet these needs and provide further related advantages.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In one aspect, the present disclosure provides a method of reducing free trimethylamine ("TMA"), the method comprising contacting TMA molecules with an absorbent material comprising a cellulosic fibrous substrate and a carboxylic acid coupled to the cellulosic fibrous substrate, wherein the reduction in free TMA is relative to a control.

In another aspect, the present disclosure provides a method of depleting TMA molecules, the method comprising contacting the TMA molecules with an absorbent material comprising a matrix of cellulose fibers and a carboxylic acid coupled to the matrix of cellulose fibers.

In yet another aspect, the present disclosure provides an absorbent article comprising an absorbent material, wherein the absorbent material comprises a fibrous matrix and a carboxylic acid coupled to the fibrous matrix, wherein the fibrous matrix comprises fibers selected from the group consisting of cellulose fibers and cellulose-based fibers, and wherein the absorbent article is a feminine hygiene product or a meat packaging pad.

In another aspect, the present disclosure provides a method of measuring a reduction in free TMA subtracted by an absorbent material, the method comprising: contacting the absorbent material disposed in a container with an amount of TMA; withdrawing a portion of the gas headspace of the vessel; measuring the amount of free TMA in the withdrawn portion of the gas headspace; and determining a decrease in free TMA in the gas headspace relative to a control.

In yet another aspect, the present disclosure provides a method of manufacturing an absorbent article, the method comprising: preparing an absorbent material comprising a fibrous matrix and a carboxylic acid coupled to the fibrous matrix; and coupling a fluid permeable topsheet and a fluid impermeable backsheet to the absorbent material.

Drawings

The foregoing aspects and many of the attendant advantages of the claimed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

figure 1 illustrates Trimethylamine (TMA) levels in the gas headspace of a vessel containing an absorbent material and a control, each contaminated with different concentrations of TMA solution, according to an embodiment of the present disclosure.

Detailed Description

Described herein are absorbent materials configured to deplete Trimethylamine (TMA), absorbent articles made therefrom, related methods of use, methods of measuring free TMA, methods of measuring a reduction in free TMA relative to a control, and related methods of making absorbent articles.

The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments of the present disclosure. It will be apparent, however, to one skilled in the art, that many embodiments of the present disclosure may be practiced without some or all of the specific details. In some instances, well known process steps have not been described in detail in order to not unnecessarily obscure aspects of the present disclosure. Further, it will be appreciated that embodiments of the present disclosure may employ any combination of the features described herein.

Absorbent material

In one aspect, the present disclosure provides an absorbent material configured to abate TMA. As used herein, "abating" refers to absorbing, adsorbing, reducing, binding, neutralizing, and/or eliminating TMA. In this regard, the absorbent materials described herein are configured to remove TMA from, for example, the gas and liquid phases in contact with the absorbent material by abatement of the TMA. As discussed further herein, this subtraction reduces the level of free TMA in the gas and liquid phases.

In an embodiment, an absorbent material described herein includes a fibrous matrix and a carboxylic acid coupled to the fibrous matrix. As further described herein, many carboxylic acids are water soluble and thus may be suitable for water-based or other solution-based treatments to couple the carboxylic acid to the fiber matrix. Certain conventional absorbent materials use powders of non-carboxylic acid compositions (e.g., activated carbon and activated carbon) to control odor. In practice, such powdered odor control components tend to cake, often flammable, and may be airborne, creating contamination and inhalation risks.

In addition, many carboxylic acids are readily available and inexpensive, making them suitable for inclusion in products that include absorbent materials. Furthermore, many carboxylic acids are also colourless and may therefore be included in the absorbent material without altering the colour of, for example, the fibrous matrix of the absorbent material. This is in contrast to certain conventional odor control components (e.g., activated carbon and activated carbon) used in some conventional absorbent articles that have dark colors that darken the color of the absorbent article.

In an embodiment, the carboxylic acid is a polycarboxylic acid. In embodiments, the polycarboxylic acid is a partially or fully neutralized salt. Without being bound by theory, and as discussed further herein with respect to fig. 1 and example 1, it is believed that the carboxylic acid group of the carboxylic acid helps to deplete TMA. Thus, since polycarboxylic acids have two or more carboxylic acid groups per carboxylic acid molecule, it is believed that each polycarboxylic acid molecule is configured to help deplete more TMA molecules than, for example, monocarboxylic acids.

In an embodiment, the carboxylic acid is selected from malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In yet another embodiment, the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In another embodiment, the carboxylic acid is selected from the group consisting of citric acid, lactic acid, salts thereof, and combinations thereof. In an embodiment, the carboxylic acid is citric acid or a salt thereof.

In embodiments, the carboxylate salt includes a carboxylate salt selected from the group consisting of sodium salts, potassium salts, ammonium salts, other metal salts, and combinations thereof.

In embodiments, the absorbent material includes a carboxylic acid content between about 0.01 wt% to about 10 wt% (also written herein as weight%). In an embodiment, the absorbent material includes a carboxylic acid content between about 0.05 wt% to about 5 wt%. In an embodiment, the absorbent material includes a carboxylic acid content between about 0.1% to about 1% by weight. In embodiments, the absorbent material comprises a carboxylic acid content of about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, or 0.09% by weight. In embodiments, the absorbent material comprises a carboxylic acid content of about 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, or 0.9% by weight. In embodiments, the absorbent material comprises a carboxylic acid content of about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, or 9% by weight.

In addition, because the absorbent materials and absorbent articles described herein reduce TMA, a component that masks TMA malodor (e.g., perfume) is not necessary to reduce TMA malodor. Thus, in embodiments, the absorbent material described herein does not comprise a perfume. Such perfume-free absorbent materials may be advantageous for users who are, for example, sensitive or allergic to perfumes or who do not like to use products comprising perfumes. It should also be noted that the absorbent materials and absorbent articles described herein can react with and abate other base molecules with malodor.

In an embodiment, the fibrous matrix comprises a cellulose pulp structure. In an embodiment, the cellulose pulp structure includes a matrix of cellulose fibers, cellulose-based fibers, or a combination thereof, and a carboxylic acid coupled to the fiber matrix. In an embodiment, the cellulose-based fibers are selected from the group consisting of viscose, modal, lyocell and combinations thereof. In an embodiment, the fibrous matrix comprises fluff pulp. In an embodiment, the fibrous substrate comprises southern bleached softwood kraft pulp.

In an embodiment, the fibrous matrix comprises synthetic fibers. In an embodiment, the fibrous matrix comprises non-woven synthetic fibers. In an embodiment, the fibrous matrix comprises a mixture of synthetic and natural fibers.

As discussed further herein, the absorbent materials described herein include a carboxylic acid coupled to a fibrous matrix. In embodiments, the carboxylic acid is coupled directly to the fiber matrix without, for example, a binder, bonding agent, or other intermediate composition or molecule between the carboxylic acid and the fiber matrix. In an embodiment, the carboxylic acid coupled to the fibrous substrate comprises a carboxylic acid covalently bound to the fibrous substrate. In an embodiment, the carboxylic acid coupled to the fibrous substrate comprises a carboxylic acid that is non-covalently bound to the fibrous substrate. Such non-covalent coupling can occur, for example, through hydrogen bonding, van der waals forces, ionic bonding, and combinations thereof.

In embodiments, the absorbent materials described herein do not include a binder, such as a silicone polymer binder, that couples to and binds the carboxylic acid to the fibrous matrix. Without being bound by theory, it is believed that in certain embodiments the carboxylic acid is configured to couple directly to the fiber matrix itself without the need for a binding agent. For example, in certain embodiments, the fibrous substrate is a natural fiber comprising hydroxyl groups coupled with a carboxylic acid without a binder, such as a silicone polymer binder.

In this regard, absorbent materials and absorbent articles made therefrom comprising carboxylic acids directly coupled to a fibrous substrate also do not require a bag or other sealed container, for example, to contain powders (e.g., activated carbon or activated carbon) that may escape from the absorbent material or absorbent article.

In an embodiment, the carboxylic acid is applied to the fibrous substrate in solid form, for example in powder or granule form. In an embodiment, the solid carboxylic acid is coupled to the fibrous matrix by a binder. In an embodiment, the adhesive is a physical adhesive. In an embodiment, the binder is a chemical binder.

In an embodiment, the solid carboxylic acid is applied to the fiber matrix at a water content equal to or greater than the fiber saturation point ("FSP"), typically from about 20% to about 25% water by weight. Without being bound by theory, it is believed that in certain embodiments, the solid carboxylic acid at least partially dissolves when in contact with and coupled to the wet fibrous matrix. Thus, in this embodiment, the water content of the fibrous matrix of about 20% to about 99.9% by weight water is sufficient to at least partially dissolve the solid carboxylic acid.

In the examples, the absorbent materials described herein are free or substantially free of inorganic peroxide (in which case, "substantially free of inorganic peroxide" is understood to mean an amount of inorganic peroxide between 0 wt% and 1 wt%, as limited by known detection methods).

TMA reduction can also be observed by utilizing oxidized cellulose fibers, which can be made by known methods (see, for example, US 8,007,635, incorporated herein by reference in its entirety).

As described above, the absorbent material of the present disclosure is configured to abate TMA. In embodiments, the absorbent material of the present disclosure is configured to have a greater than or equal to about 6.15409x10 reduction per about 1g of absorbent material at an equilibrium state of 25 ℃^-5g of TMA (in this case, "equilibrium" is understood to mean the point in time at which the TMA entering the gas headspace of the test apparatus reaches steady state) wherein the absorbent material is treated with 0.01 wt% of a carboxylic acid selected from one of the groups provided herein. In an embodiment, the absorbent material is configured to have a greater than or equal to about 6.15409x10 reduction per about 1g of absorbent material at an equilibrium state of 25 ℃^-5g TMA wherein the absorbent material is treated with 0.01 wt% citric acid.

As further discussed herein with respect to the methods of the present disclosure, in an embodiment, the amount of TMA subtracted by the absorbent material described herein is determined by measuring the amount of TMA in the gas headspace of a closed vessel containing the absorbent material and an initial amount of TMA. In an embodiment, determining the amount of free TMA when the TMA is depleted by the absorbent material comprises contacting a known amount of absorbent material disposed in the closed vessel with an initial known amount of TMA; after the absorbent material has been exposed to the initial amount of TMA and allowed to equilibrate within the gas headspace, withdrawing a portion of the gas headspace from the closed vessel; and measuring the gas concentration (e.g., ppm) of TMA in the withdrawn portion of the gas headspace.

In an embodiment, the gas headspace has a volume of less than 1L. In an embodiment, the gas headspace has a volume of about 0.5L. In an embodiment, the container is a flexible container.

As discussed further herein, in embodiments, the amount of TMA subtracted by the absorbent material is measured relative to a control absorbent material, e.g., a control absorbent material that does not include a carboxylic acid coupled to the fibrous substrate, as further described herein with respect to example 1, or alternatively, the control sample may be run with a container that does not include any absorbent material (i.e., a blank).

In embodiments, the absorbent material described herein is configured to subtract TMA from a solution in contact with the absorbent material and subtract TMA from a gas phase in contact with the absorbent material. In this regard, the absorbent material is configured to eliminate or reduce TMA malodor by abatement of gaseous and dissolved or liquid TMA.

As discussed further herein, the absorbent materials of the present disclosure are configured to abate TMA. In an example, by quantifying the ability of TMA to abate, the absorbent material is configured to reduce the gas concentration of free TMA within the gas headspace of a test apparatus (described in detail below) by 50% relative to a control (see discussion of appropriate controls above). In an embodiment, the absorbent material is configured to reduce the amount of free TMA entering (or otherwise entering) the gas headspace by 75% relative to a control. In an embodiment, the absorbent material is configured to reduce the amount of free TMA entering (or otherwise entering) the gas headspace by 85% relative to a control. In an embodiment, the absorbent material is configured to reduce the amount of free TMA entering (or otherwise entering) the gas headspace by 90% relative to a control. In an embodiment, the absorbent material is configured to reduce the amount of free TMA entering (or otherwise entering) the gas headspace by 95% relative to a control. In an embodiment, the absorbent material is configured to reduce the amount of free TMA entering (or otherwise entering) the gas headspace by 99% relative to a control. In an embodiment, the absorbent material is configured to reduce the amount of TMA entering (or otherwise entering) the gas headspace by substantially 100% relative to a control (in which case, "substantially 100%" is understood to mean an amount between 99% and 100%, which is limited by the detection methods described herein).

As discussed further herein, in embodiments, the cellulosic fibrous matrix of absorbent material is capable of reducing free TMA from the gas headspace by reducing TMA. In an example, when the absorbent material included 0.45 wt% citric acid, TMA was introduced into the liquid solution at about 0.034 wt%, and the control was an absorbent material consisting of an equivalent amount of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulosic fibrous matrix of the absorbent material was capable of reducing free TMA by at least about 95ppm in a gas headspace of about 0.5L. In this case, "equivalent amount" is understood to mean an amount of control fluff pulp having a mass of 95% to 105% of the mass of the absorbent material, which is limited by known detection methods.

In an example, when the absorbent material includes 0.45 wt% citric acid, TMA is introduced into the liquid solution at about 0.027 wt%, and the control is an absorbent material consisting of an equivalent amount of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulosic fibrous matrix is capable of reducing free TMA by at least about 99% in a gas headspace of about 0.5L. In an example, when the absorbent material includes 0.45 wt% citric acid, TMA is introduced into the liquid solution at about 0.05 wt%, and the control is an absorbent material consisting of an equivalent amount of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulosic fibrous substrate is capable of reducing free TMA by at least about 50% in a gas headspace of about 0.5L.

As further discussed herein with respect to methods of reducing the amount of free TMA, in embodiments, measuring the reduction in free TMA subtracted by the absorbent material of the present disclosure comprises contacting the absorbent material disposed in the vessel with an amount of TMA; withdrawing a portion of the gas headspace of the vessel; measuring the amount of free TMA in the withdrawn portion of the gas headspace; and determining a decrease in free TMA in the gas headspace relative to the control.

In embodiments, the absorbent material described herein may optionally further comprise an additive selected from the group consisting of activated carbon, flavorants, zeolites, and combinations thereof. Although the absorbent materials of the present disclosure are configured to reduce TMA in the absence of such additives, in certain embodiments, the absorbent materials also include materials such as other TMA malodor control components configured to non-selectively absorb or mask certain other malodors or supplement the absorbent material, including but not limited to activated carbon, zeolites, or perfumes.

In an embodiment, the absorbent material further comprises a superabsorbent polymer to assist in absorbing fluids.

Absorbent article

In another aspect, the present disclosure provides an absorbent article comprising the absorbent material of the present disclosure. As discussed further herein, odor control and prevention in feminine hygiene products and meat packaging products, particularly related to TMA malodor, is of concern. Because the absorbent materials of the present disclosure are configured to reduce TMA, they are particularly suitable for use in feminine hygiene products and meat packaging products.

Thus, in an embodiment, an absorbent article includes a fibrous substrate and a carboxylic acid coupled to the fibrous substrate. In an embodiment, the fibrous matrix comprises fibers selected from the group consisting of cellulose fibers, cellulose-based fibers, and combinations thereof.

In an embodiment, the absorbent article comprises a fluid permeable topsheet. The fluid permeable topsheet comprises a highly fluid permeable material configured to move fluid, e.g. from a wearer, to the absorbent material. In an embodiment, the fluid permeable topsheet comprises a material selected from the group consisting of hydrophilic woven materials, hydrophilic nonwoven materials, airlaid webs, wet-laid webs, films comprising apertures, open-cell foams, and batting.

In an embodiment, the absorbent article comprises a fluid impermeable backsheet. The fluid impermeable backsheet is configured to prevent liquid from migrating from the absorbent material through the fluid impermeable sheet to, for example, the wearer's clothing.

In embodiments, the absorbent material forms at least a portion of an absorbent core of the absorbent article. In embodiments, the absorbent material is disposed between the fluid permeable topsheet and the fluid impermeable backsheet. In embodiments, the fluid permeable topsheet and the fluid impermeable backsheet are suitably sealed to enclose the absorbent material. In an embodiment, the absorbent material is arranged within the fluid permeable topsheet.

In an embodiment, the absorbent article is a feminine hygiene product. As further described herein, in embodiments, the absorbent materials described herein comprise a fibrous matrix and a carboxylic acid coupled to the fibrous matrix. In this regard, without being bound by theory, it is believed that an absorbent article comprising the absorbent material of the present disclosure reduces TMA malodor associated with vaginal fluids in at least two ways: (1) the carboxylic acid reduces vaginal pH, thereby inhibiting growth of anaerobic bacteria, and (2) the carboxylic acid depletes TMA molecules, thereby reducing free TMA, as discussed further herein.

In an embodiment, the feminine hygiene product is selected from the group consisting of pantiliners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, disposable menstrual protection undergarments, and tampons. In an embodiment, the feminine hygiene product is selected from the group consisting of pantiliners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, and disposable menstrual protection undergarments. In some embodiments, the absorbent articles of the present disclosure are not in the form of tampons. Feminine hygiene products can be made according to known methods (see, e.g., U.S. patent No. 9,717,817, and patents cited therein, which are incorporated by reference herein in their entirety).

In an embodiment, the feminine hygiene product is configured to be worn externally. As used herein, a feminine hygiene product configured to be worn externally is configured to be worn externally of the vagina. In embodiments, the feminine hygiene product is not configured to be worn internally. As used herein, a feminine hygiene product configured to be worn internally is a feminine hygiene product configured to be worn at least partially within the vagina.

In an embodiment, an absorbent material in a feminine hygiene product comprises an absorbent material comprising a fibrous substrate and a carboxylic acid coupled to the fibrous substrate, wherein the absorbent material comprises a carboxylic acid content of between about 0.01 wt% to about 10 wt%.

In an embodiment, the absorbent article is a meat packaging pad. Meat packaging cushions may include those known in the art and may be manufactured according to known methods (see, e.g., U.S. patent nos. 5,908,649 and 7,655,829, the entire contents of which are incorporated herein by reference). As further described herein, TMA malodor emanates from meat products, such as fish products, and there is a need to abate TMA in meat packaged products. Because the absorbent materials described herein are configured to reduce TMA, they are particularly suitable for use in meat packaging products. In an embodiment, the meat packaged product is a meat packaging cushion. In an embodiment, the meat packaging mat is a fish packaging mat. In an embodiment, a meat packaging cushion comprising an absorbent material of the present disclosure is configured to absorb meat juices, such as fish juices and other liquids, and to deplete TMA.

In an embodiment, the absorbent material in the meat packaging mat comprises a fibrous matrix and a carboxylic acid coupled to the fibrous matrix, and wherein the absorbent material comprises a carboxylic acid content of between about 0.01 wt% to about 10 wt%. In an embodiment, the meat packaging cushion includes a super absorbent polymer to help absorb fluids. In an embodiment, the superabsorbent polymer is disposed within the absorbent material.

Method for reducing free TMA

As further described herein, TMA malodor, and TMA molecules, for example from vaginal fluids or juices, and TMA malodor produced therefrom, may be reduced by the reduction of TMA by the absorbent material or absorbent article of the present disclosure. By reducing TMA into the absorbent material or an absorbent article made of absorbent material, TMA malodour is reduced relative to a similar situation for undiminished TMA, such that for example free TMA is present at a level where it cannot be smelled by the person's nose or where it can be smelled by the person's nose at a greatly reduced level.

Thus, in another aspect, the present disclosure provides a method of reducing free TMA. As used herein, "free TMA" refers to the amount of TMA in or to be equilibrated into the gas headspace and capable of being measured and/or smelled by a person's nose. Free TMA is in contrast to TMA molecules which are, for example, depleted by the absorbent material or absorbent article and are therefore not available for measurement or detection by the nose of a person.

In an embodiment, a method of reducing the level of free TMA comprises contacting TMA molecules with an absorbent material comprising a matrix of cellulose fibers and a carboxylic acid coupled to the matrix of cellulose fibers. In an embodiment, the method further comprises depleting TMA molecules.

As further described herein, the absorbent materials of the present disclosure and absorbent articles made therefrom are configured to subtract TMA from either or both of the liquid and/or gas phases. Thus, in an embodiment, contacting the TMA with the absorbent material or absorbent article comprises contacting the TMA in a solution phase, such as dissolved in vaginal fluids, menses, or gravy. In an embodiment, TMA molecules are in a liquid. In an embodiment, the liquid TMA is TMA molecules dissolved in a solution or suspension. In an embodiment, the liquid TMA is pure TMA liquid. In an embodiment, contacting the TMA with the absorbent material or absorbent article comprises contacting menstrual fluid comprising the TMA with the absorbent material or absorbent article. In an embodiment, contacting the TMA with an absorbent material or an absorbent article comprises contacting a meat fluid, e.g. a fish fluid, comprising the TMA with an absorbent material or an absorbent article.

Accordingly, in an embodiment, contacting the TMA with the absorbent material or absorbent article comprises contacting the TMA in a gas phase, such as TMA volatilized from vaginal fluids, menses, or meat juices.

In embodiments, the absorbent material is any absorbent material described herein. In an embodiment, the absorbent article is any of the absorbent articles described herein. In an embodiment, the fibrous substrate is a cellulosic fibrous substrate (see below).

In an embodiment, the carboxylic acid is selected from malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In an embodiment, the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof. In an embodiment, the carboxylic acid is citric acid or a salt thereof.

In embodiments, the absorbent material includes a carboxylic acid content between about 0.01% to about 10% by weight. In an embodiment, the absorbent material includes a carboxylic acid content between about 0.05 wt% to about 5 wt%. In an embodiment, the absorbent material includes a carboxylic acid content between about 0.1% to about 1% by weight. In embodiments, the absorbent material comprises a carboxylic acid content of about 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, or 0.09% by weight. In embodiments, the absorbent material comprises a carboxylic acid content of about 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, or 0.9% by weight. In embodiments, the absorbent material comprises a carboxylic acid content of about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, or 9% by weight.

In an embodiment, contacting TMA with the absorbent material or an absorbent article made from the absorbent material reduces at least 50% of free TMA that may leave or re-enter the absorbent material or absorbent article as gaseous compounds. In an embodiment, contacting TMA with the absorbent material or an absorbent article made from the absorbent material reduces at least 75% of free TMA that may leave or re-enter the absorbent material or absorbent article as gaseous compounds. In an embodiment, contacting TMA with an absorbent material or an absorbent article made from an absorbent material reduces at least 85% of free TMA that may exit or re-enter the absorbent material or absorbent article. In an embodiment, contacting TMA with an absorbent material or an absorbent article made from an absorbent material reduces at least 95% of free TMA that may exit or re-enter the absorbent material or absorbent article. In an embodiment, contacting TMA with an absorbent material or an absorbent article made from an absorbent material reduces at least 99% of free TMA that may exit or re-enter the absorbent material or absorbent article.

Method of measuring reduction of free TMA

In another aspect, the present disclosure provides a method of measuring a reduction in free TMA that is subtracted by an absorbent material (e.g., an absorbent material of the present disclosure or an absorbent article made therefrom). In an embodiment, the absorbent material is arranged in a closed container and is in contact with a quantity of TMA. After the absorbent material has had the opportunity to deplete at least a portion of the amount of TMA, and for example, the amount of TMA has reached equilibrium between the gas headspace of the closed vessel and the absorbent material, a portion of the gas headspace is withdrawn from the closed vessel. In an embodiment, prior to withdrawing a portion of the gas headspace from the containment vessel, a quantity of TMA is contacted with the absorbent material for a sufficient time to reach equilibrium, thereby also providing sufficient time for at least a portion of the initial quantity of TMA to be depleted within the absorbent material. One of ordinary skill in the art will readily know how to generate a balance curve or other suitable tool to monitor and identify balance.

In an embodiment, the containment vessel is a flexible vessel configured to at least partially collapse in response to a portion of the extraction gas headspace. In this regard, it is easier for the user to extract a portion of the gas headspace from the containment vessel.

The withdrawn portion of the gas headspace was measured to determine the gas concentration of free TMA present in the headspace. In an embodiment, measuring the amount of free TMA in the withdrawn portion comprises passing the gas-headspace withdrawn portion through a stationary phase loaded with a colorimetric label that changes color upon contact with TMA; and measuring the amount of color change in the stationary phase in response to passing the withdrawn portion of the gas headspace through the stationary phase. In an embodiment, determining the drawn portion of the gas headspace to measure the gas concentration of free TMA comprises using a colorimetric gas detection tube, e.g.

And a gas detection pipe system. Although a colorimetric detection method is described, it will be understood that other TMA detection methods consistent with the methods of the present disclosure may be used, such as, but not limited to, gas chromatography.

The reduction in free TMA was measured relative to the control. In an embodiment, the control is a blank, wherein the blank comprises a control that does not comprise contacting TMA molecules with an absorbent material. In the examples, the control is an absorbent material control, wherein the absorbent material control is an absorbent material substantially free or free of added carboxylic acid coupled to the fibrous substrate (in this case, "substantially free of added carboxylic acid" or "substantially free of added carboxylic acid" is understood to mean no added carboxylic acid or an amount of added carboxylic acid between 0 wt% and 1 wt%, as limited by known detection methods). As used herein, "adding carboxylic acid" is understood to mean the amount of carboxylic acid added or otherwise coupled to the absorbent material on or over any carboxylic acid present in the untreated absorbent material during treatment or manufacture. In an embodiment, the control absorbent material comprises fluff pulp, such as southern bleached softwood kraft pulp, that is not treated with or otherwise coupled to a carboxylic acid. In this regard, the user may determine the amount of TMA reduction produced by carboxylic acid coupled to the fibrous matrix of the absorbent material described herein relative to the selected control.

In an embodiment, the amount of TMA (TMA) that is not depleted by the absorbent material and allowed to equilibrate within the gas headspace_g) Amount of TMA (TMA) that was not allowed to equilibrate within the control gas headspace in the control experiment_c) A comparison is made. The reduction in gas concentration of free TMA measured in the headspace above the absorbent material relative to the control may be expressed as a percentage reduction in free TMA (% TMA)_red). The percentage reduction can be calculated by the following formula.

It should be noted that TMA-containing fluids (e.g., fluids used to contaminate absorbent materials or absorbent articles) residing on the sides or other portions of the containment vessel may distort the TMA reduction results. Such TMA-containing fluid that is not in contact with the absorbent material or absorbent article may cause an increase in volatilization of TMA from the TMA-containing solution into the gas headspace of the closed vessel. Such increased TMA volatilization may result in a higher relative gas TMA concentration than would contaminate a solution containing TMA directly onto the absorbent material or absorbent article, falsely indicating the ability (or lack of ability) of the absorbent material or absorbent article to reduce TMA.

Method for reducing TMA

As further described herein, the absorbent material and absorbent articles made therefrom are capable of reducing TMA. Thus, in another aspect, the present disclosure provides a method of depleting TMA molecules. In an embodiment, a method of abating TMA comprises contacting TMA molecules with an absorbent material or an absorbent article made therefrom, the absorbent material comprising a fibrous substrate and a carboxylic acid coupled to the fibrous substrate. In an embodiment, the method further comprises depleting TMA molecules in the absorbent material or an absorbent article made therefrom.

In embodiments, the absorbent material is any absorbent material described herein. In an embodiment, the absorbent article is any of the absorbent articles described herein. In an embodiment, the fibrous substrate is a cellulosic fibrous substrate. In an embodiment, the cellulosic fibrous substrate comprises a cellulosic pulp structure. In an embodiment, the cellulosic fibrous matrix comprises fibers selected from the group consisting of cellulosic fibers and cellulose-based fibers. In an embodiment, the cellulose-based fibers are selected from the group consisting of viscose, modal, lyocell and combinations thereof.

In an embodiment, contacting the TMA molecule with the absorbent material or absorbent article comprises contacting a liquid (e.g. menstrual fluid) comprising TMA with the absorbent material or an absorbent article made therefrom. In an embodiment, contacting TMA molecules with an absorbent material comprises contacting a meat fluid comprising TMA molecules with an absorbent material or an absorbent article made therefrom. In an embodiment, the TMA molecules are in the gas phase, which is in contact with the absorbent material or absorbent article.

In embodiments, the absorbent materials of the present disclosure and the fibrous substrates of the absorbent articles made therefrom are capable of depleting TMA molecules such that when the absorbent material comprises 0.45 wt% citric acid, about 0.5L of gas headspace at equilibrium contains less than about 1, 2, 3, 4, 5, 10, 20, 30, 40, or 50ppm of free TMA. In embodiments, the absorbent materials of the present disclosure and the fibrous substrates of the absorbent articles made therefrom are capable of depleting TMA molecules such that when the absorbent material comprises 0.01 wt% citric acid and TMA molecules are introduced into the liquid solution at between about 0.0005 wt% to about 0.034 wt%, a gas headspace of about 0.5L at equilibrium contains less than about 50ppm free TMA. In embodiments, the absorbent materials of the present disclosure and the fibrous matrix of the absorbent articles made therefrom are capable of depleting TMA molecules such that when the absorbent material comprises 0.01 wt% citric acid and TMA molecules are introduced into the liquid solution at about 0.0005%, 0.001%, 0.005%, 0.01%, 0.015%, 0.02%, 0.025%, 0.027%, 0.03%, 0.034%, or 0.035%, a gas headspace of about 0.5L at equilibrium contains less than about 50ppm free TMA. In an embodiment, the cellulosic fibrous matrix is capable of depleting TMA molecules such that when the absorbent material comprises 0.01 wt% citric acid and TMA molecules are introduced into the liquid solution at about 0.034 wt%, about 0.5L of the gas headspace at equilibrium contains less than about 10ppm free TMA. In an embodiment, the cellulosic fibrous matrix is capable of depleting TMA molecules such that when the absorbent material comprises 0.01 wt% citric acid and TMA molecules are introduced into the liquid solution at about 0.027 wt%, about 0.5L of the gas headspace at equilibrium contains less than about 5ppm of free TMA.

In an example, when the absorbent material includes 0.01 wt% citric acid, TMA is introduced into the liquid solution at about 0.034 wt%, and the control is an absorbent material consisting of an equivalent amount of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulosic fibrous substrate is capable of reducing free TMA by at least about 95ppm in a gas headspace of about 0.5L.

In an embodiment, wherein the cellulosic fibrous substrate is capable of reducing free TMA by at least about 99% in about 0.5L of gas headspace when the absorbent material comprises 0.01 wt% citric acid, TMA is introduced into the liquid solution at about 0.027 wt%, and the control is an absorbent material consisting of an equivalent amount of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid. In an example, when the absorbent material includes 0.01 wt% citric acid, TMA is introduced into the liquid solution at about 0.05 wt%, and the control is an absorbent material consisting of an equivalent amount of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid, the cellulosic fibrous substrate is capable of reducing free TMA by at least about 50% in a gas headspace of about 0.5L.

In embodiments, determining the amount of free TMA after the absorbent material described herein has depleted TMA comprises contacting the absorbent material disposed in the vessel with an initial amount of TMA in the liquid solution; withdrawing a portion of the gas headspace of the vessel; the amount of free TMA in the withdrawn portion of the gas headspace is measured, for example, in ppm. The measuring step can be performed in any suitable manner, including the solid phase colorimetric gas detection tubes described herein, gas chromatography, and the like. Without wishing to be bound by theory, it is believed that in the liquid solution in contact with the absorbent materialTMA will react with carboxylic acid and be reduced to RCOO^-N⁺(Me)₃Salt, thus eliminating TMA malodor by reducing TMA available for TMA volatilization and equilibration into the gas headspace of the experimental vessel apparatus.

Method of manufacturing absorbent article

As further described herein, the absorbent materials of the present disclosure and absorbent articles made therefrom are suitable for use as, for example, an absorbent core or other absorbent portion of an absorbent article (e.g., a feminine hygiene product) due to their ability to absorb TMA. Thus, in another aspect, the present disclosure provides a method of making an absorbent article, such as feminine hygiene products and meat packaging pads, that includes the absorbent material of the present disclosure. In an embodiment, the method includes preparing an absorbent material comprising a fibrous matrix and a carboxylic acid coupled to the fibrous matrix; and coupling the fluid permeable topsheet and the fluid impermeable backsheet to the absorbent material. In an embodiment, preparing the absorbent material includes forming a cellulose pulp structure by forming a sheet of cellulose pulp from cellulose pulp, and forming a matrix of cellulose fibers from the cellulose pulp. In the examples, the carboxylic acid is added by applying the acid in aqueous form to the pulp sheet. As also described further herein, in embodiments, the carboxylic acid is added in solid form, e.g., with a binder or adhesive.

In embodiments, the absorbent material is any absorbent material described herein, including a fibrous matrix and a carboxylic acid coupled to the fibrous matrix. In embodiments, the fluid permeable topsheet is any fluid permeable topsheet described herein. In embodiments, the fluid impermeable backsheet is any fluid impermeable backsheet described herein.

In embodiments, the fluid permeable topsheet and the fluid impermeable backsheet are coupled to the absorbent material by a coupling method selected from the group consisting of sewing, coupling with an adhesive, heat sealing, ultrasonic welding, and combinations thereof.

In embodiments, the fluid permeable topsheet and the fluid impermeable backsheet are coupled around the absorbent material and the absorbent material is disposed between the fluid permeable topsheet and the fluid impermeable backsheet. In this regard, the absorbent material forms at least a portion of an absorbent core of the absorbent article. In an embodiment, the absorbent material is disposed within the fluid permeable topsheet.

In an embodiment, the feminine hygiene product is selected from the group consisting of pantiliners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, disposable menstrual protection undergarments, and tampons. In an embodiment, the feminine hygiene product is selected from the group consisting of pantiliners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, and disposable menstrual protection undergarments. In some embodiments, the absorbent articles of the present disclosure are not in the form of tampons. Feminine hygiene products can be made according to known methods (see, e.g., U.S. patent No. 9,717,817, incorporated by reference herein in its entirety).

In an embodiment, the feminine hygiene product is configured to be worn externally. In embodiments, the feminine hygiene product is not configured to be worn internally.

In an embodiment, the absorbent article is a meat packaging pad. In an embodiment, the meat packaging mat is a fish packaging mat. Meat packaging cushions may include those known in the art and may be manufactured according to known methods (see, e.g., U.S. patent nos. 5,908,649 and 7,655,829, the entire contents of which are incorporated herein by reference).

Examples of the invention

Example 1: fluff pulp reduction TMA with citric acid treatment

The fluff pulp treated with citric acid (0.45 wt%) and the untreated fluff pulp were fiberized to form a mat, placed in a sealed container, and soiled with TMA solution. Untreated fluff pulp came from the same manufacturing plant as the citric acid treated fluff pulp, but was not buffered.

The fluff pulp sheet was fiberized and the fluff pulp was then formed into a 2 inch diameter mat with an average weight of 0.94 ± 0.02 g. The pads were compressed in a press to a pressure of 2000 psi.

The test container was made of a 500mL water bottle selected for its compressibility. A 16 gauge needle was passed through the plastic cap of the water bottle, glued in place, and sealed with silicone caulk. A rubber tube is placed around the shank of the needle to make an airtight seal between the shank and the measuring device.

The compressed fluff round was introduced into a test vessel, contaminated with 15g of solution, sealed, and then the headspace TMA above was tested after 2 hours. TMA solutions were tested at four concentrations: 0.0005%, 0.027%, 0.034% and 0.05% by weight. According to literature values, TMA levels of normal vaginal fluids not associated with bacterial vaginosis are 0.0005 wt.%.

TABLE 1 TMA solution

Two hours after contamination, the vessel was tested for TMA concentration in the headspace above the control and test slurries. Using 105SE type

A tube. These tubes are labeled for use with ammonia, but could also be used with TMA. The actual TMA concentration is determined by

The reading is multiplied by a conversion factor of 0.5.

A total of 25 samples were tested: 11 untreated control fluff pulp samples and 14 test fluff pulp samples treated with citric acid. At least two samples per concentration were averaged. When the first two results change, three or more samples are tested per concentration. Prior to measuring TMA in the vessel gas headspace, 25 samples were allowed to interact with TMA contaminants at 25 ℃ for about 2 hours to ensure equilibrium.

TMA concentration in the headspace above the pad was compared for the test fluff pulp treated with citric acid and the untreated control fluff pulp. As summarized in table 2 and fig. 1, it was found that fluff pulp treated with citric acid reduced the headspace concentration of TMA by different amounts. As shown, citric acid treated villi were found to eliminate TMA volatilization at the literature concentration in healthy vaginal fluid, at 0.0005 wt%, and at 0.027 wt% that is 60 times that concentration. At 0.034 wt% of the literature value, 70 times, it was found that citric acid treated fluff reduced odor volatilization by 95% on average into the headspace. The ability of citric acid-treated villi to continue to inhibit TMA volatilization into the headspace was not inhibited until a 100-fold concentration of TMA was found in healthy vaginal fluid at 0.05 wt.%. Even at this concentration, the headspace odor level of the citric acid-treated fluff was 71.1% less than the untreated fluff on average.

TABLE 2 reduction of free TMA in the headspace after contact with treated and untreated fluff pulp

The citric acid-treated fluff pad had an average concentration of 0.33ppm TMA in the headspace of 0.027% TMA solution. The average concentration of TMA in the headspace of the untreated slurry was 72ppm TMA. Citric acid treated fluff reduced TMA in the headspace by 99.5%.

The citric acid treated fluff in 0.034% TMA solution read an average TMA concentration in the headspace of 5 ppm; the average TMA level of the untreated slurry in the gas headspace was 100 ppm. It should be noted that it is possible to note,

the detection limit of the tube was 100 ppm. Thus, the actual average TMA level in the gas headspace may already be above 100 ppm. Citric acid treated fluff reduced TMA readings in the headspace by at least 95%.

In the 0.05% solution, the citric acid treated fluff read an average TMA concentration in the headspace of 26.8 ppm. However, the citric acid treated fuzz reading at this concentration ranged from 10 to 51 ppm. In contrast, the maximum change between any other two sample points at other concentrations was 7ppm (between 68ppm and 75ppm for 0.03% untreated pulp).

For two of the three readings taken, the TMA concentration in the headspace above the untreated fluff was higher than the maximum reading of the sensor. Since the exact concentration cannot be known, these data have been reported as 100ppm sensor readings. It can be estimated, but is only an estimate, how much higher the actual concentration is than the maximum reading based on how fast the sensor reaches its maximum, how far the colorimetric reading stops exceeding the maximum, and the malodors encountered by the tester (TMA produces fishy smell at low concentrations, but ammonia-like smell at high concentrations). These observations have been recorded in test records.

It should be noted that for purposes of this disclosure, terms such as "upper", "lower", "vertical", "horizontal", "inward", "outward", "forward", "rearward", etc., are to be construed as descriptive and not limiting the scope of the claimed subject matter. Furthermore, the use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms "connected," "coupled," and "mounted," and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. The term "about" means plus or minus 5% of the stated value.

The principles, representative embodiments and modes of operation of the present disclosure have been described in the foregoing description. However, the aspects of the present disclosure that are intended to be protected are not to be construed as limited to the particular embodiments disclosed. Furthermore, the embodiments described herein are to be considered as illustrative and not restrictive. It will be understood that changes and variations may be made by others, and equivalents may be employed, without departing from the spirit of the present disclosure. Accordingly, it is expressly intended that all such variations, changes and equivalents fall within the spirit and scope of the claimed disclosure.

Claims

1. A method of reducing free trimethylamine ("TMA"), the method comprising contacting TMA molecules with an absorbent material comprising a cellulosic fibrous substrate and a carboxylic acid coupled to the cellulosic fibrous substrate, wherein the reduction in free TMA is relative to a control.

2. The method of claim 1, wherein the TMA molecule is in a liquid.

3. The method of claim 2, wherein the TMA molecule is in menstrual fluid.

4. The method of claim 2, wherein the TMA molecules are in a meat fluid.

5. The method of claim 1, wherein the TMA molecules are in a gas.

6. The method of claim 1, wherein the control is a blank control.

7. The method of claim 1, wherein the control is an absorbent material control.

8. The method of claim 1 wherein the cellulosic fibrous substrate comprises a cellulosic pulp structure.

9. The method of claim 1, wherein the cellulosic fibrous substrate comprises fibers selected from the group consisting of cellulosic fibers and cellulose-based fibers.

10. The method of claim 9, wherein the cellulose-based fibers are selected from the group consisting of viscose, modal, lyocell, and combinations thereof.

11. The method of claim 1, wherein the carboxylic acid is selected from malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.

12. The method of claim 1, wherein the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.

13. The method of claim 1, wherein the carboxylic acid is citric acid or a salt thereof.

14. The method of any of claims 1-13, wherein the absorbent material comprises a carboxylic acid content between about 0.01 wt% to about 10 wt%.

15. The method of claim 1, wherein the cellulosic fibrous substrate is capable of reducing free TMA by at least about 95ppm in a headspace of about 0.5L when the absorbent material comprises 0.01 wt% citric acid, the TMA is introduced into the liquid solution at about 0.034 wt%, and the control is an absorbent material consisting of an equivalent amount of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid.

16. The method of claim 15, wherein the reduction in free TMA is measured by a process comprising:

contacting the absorbent material disposed in a container with an amount of TMA;

withdrawing a portion of the gas headspace of the vessel;

measuring the amount of free TMA in the withdrawn portion of the gas headspace; and

a decrease in free TMA in the gas headspace relative to a control was determined.

17. The method according to claim 1, wherein the cellulosic fibrous substrate is capable of reducing free TMA by at least about 99% in a headspace of about 0.5L when the absorbent material comprises 0.01 wt% citric acid, the TMA is introduced into the liquid solution at about 0.027 wt%, and the control is an absorbent material consisting of an equivalent amount of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid.

18. The method of claim 1, wherein the cellulosic fibrous substrate is capable of reducing free TMA by at least about 50% in a headspace of about 0.5L when the absorbent material comprises 0.01 wt% citric acid, the TMA is introduced into the liquid solution at about 0.05 wt%, and the control is an absorbent material consisting of an equivalent amount of southern bleached softwood kraft fluff pulp substantially free of any added carboxylic acid.

19. The method of any one of claims 17 and 18, wherein the reduction in free TMA is measured by a process comprising:

withdrawing a portion of the gas headspace of the vessel;

20. A method of depleting TMA molecules, the method comprising contacting the TMA molecules with an absorbent material comprising a cellulose fiber matrix and a carboxylic acid coupled to the cellulose fiber matrix.

21. The method of claim 20, wherein the TMA molecule is in a liquid.

22. The method of claim 21, wherein the TMA molecule is in menstrual fluid.

23. The method of claim 21, wherein the TMA molecule is in a meat fluid.

24. The method of claim 20, wherein the TMA molecule is in a gas.

25. The method of claim 20 wherein the cellulosic fibrous substrate comprises a cellulosic pulp structure.

26. The method of claim 20, wherein the cellulosic fibrous substrate comprises fibers selected from the group consisting of cellulosic fibers and cellulose-based fibers.

27. The method of claim 26, wherein the cellulose-based fibers are selected from the group consisting of viscose, modal, lyocell, and combinations thereof.

28. The method of claim 20, wherein the carboxylic acid is selected from malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.

29. The method of claim 20, wherein the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.

30. The method of claim 20, wherein the carboxylic acid is citric acid or a salt thereof.

31. The method of any of claims 20-30, wherein the absorbent material comprises a carboxylic acid content between about 0.01 wt% to about 10 wt%.

32. The method of claim 20, wherein the cellulosic fibrous matrix is capable of depleting the TMA molecules such that when the absorbent material comprises 0.45 wt% citric acid and the TMA molecules are introduced into the liquid solution at about 0.05 wt%, a headspace of about 0.5L at equilibrium contains less than about 50ppm free TMA.

33. The method of claim 20, wherein the cellulosic fibrous matrix is capable of depleting the TMA molecules such that when the absorbent material comprises 0.45 wt% citric acid and the TMA molecules are introduced into liquid solution at about 0.034 wt%, a headspace of about 0.5L at equilibrium contains less than about 10ppm free TMA.

34. The method of claim 20, wherein the cellulosic fibrous matrix is capable of depleting the TMA molecules such that when the absorbent material comprises 0.45 wt% citric acid and the TMA molecules are introduced into the liquid solution at about 0.027 wt%, a headspace of about 0.5L at equilibrium contains less than about 5ppm free TMA.

35. The method of any of claims 32-34, wherein the amount of free TMA is measured by a process comprising:

contacting the absorbent material disposed in a container with an amount of TMA in a liquid solution;

withdrawing a portion of the gas headspace of the vessel; and

the amount of free TMA in the withdrawn portion of the gas headspace was measured.

36. An absorbent article comprising an absorbent material, wherein the absorbent material comprises a fibrous matrix and a carboxylic acid coupled to the fibrous matrix, wherein the fibrous matrix comprises fibers selected from the group consisting of cellulosic fibers and cellulose-based fibers, and wherein the absorbent article is a feminine hygiene product or a meat packaging pad.

37. The absorbent article of claim 36, wherein the absorbent material does not comprise a silicone polymer binder coupled to the carboxylic acid, and wherein the absorbent material does not comprise an inorganic peroxide.

38. The absorbent article of claim 36, wherein the cellulose-based fibers are selected from the group consisting of viscose, modal, lyocell, and combinations thereof.

39. The absorbent article of claim 36, further comprising:

a fluid permeable topsheet, and

a fluid impermeable backsheet;

wherein the absorbent material is disposed between the fluid permeable topsheet and the fluid impermeable backsheet.

40. The absorbent article of claim 36, further comprising:

a fluid permeable topsheet; and

a fluid-impermeable backsheet that is impermeable to fluids,

wherein the absorbent material is disposed within the fluid permeable topsheet.

41. The absorbent article of any one of claims 36-40, wherein the absorbent material forms at least a portion of an absorbent core of the absorbent article.

42. The absorbent article of any one of claims 36-41, further comprising a superabsorbent polymer.

43. The absorbent article according to any one of claims 36-42, wherein the carboxylic acid is a polycarboxylic acid.

44. The absorbent article of claim 43, wherein the polycarboxylic acid is a partially or fully neutralized salt.

45. The absorbent article of any one of claims 36-42, wherein the carboxylic acid is selected from malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.

46. The absorbent article of any one of claims 36-42, wherein the carboxylic acid is selected from the group consisting of citric acid, lactic acid, malic acid, tartaric acid, salicylic acid, succinic acid, formic acid, pyruvic acid, propionic acid, butyric acid, isobutyric acid, glycolic acid, salts thereof, and combinations thereof.

47. The absorbent article of any one of claims 36-42, wherein the carboxylic acid is citric acid or a salt thereof.

48. The absorbent article of any one of claims 36-47, wherein the absorbent material comprises a carboxylic acid content of between about 0.01 wt% to about 10 wt%.

49. The absorbent article according to any one of claims 36-48, wherein the absorbent article is a feminine hygiene product, and the feminine hygiene product is selected from the group consisting of pantiliners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, tampons, and disposable menstrual protection undergarments.

50. The feminine hygiene product of claim 49, wherein the feminine hygiene product is configured to be worn externally.

51. The feminine hygiene product of claim 49, wherein the feminine hygiene product is not configured to be worn internally.

52. The absorbent article of any one of claims 36-48, wherein the absorbent article is a meat packaging pad, and wherein the meat packaging pad is a fish-based packaging pad.

53. A method of measuring a reduction in free TMA subtracted by an absorbent material, the method comprising:

withdrawing a portion of the gas headspace of the vessel;

54. The method of claim 53, wherein the absorbent material comprises a fibrous matrix and a carboxylic acid coupled to the fibrous matrix.

55. The method of claim 53, wherein the portion of the headspace is withdrawn after the free TMA has reached equilibrium.

56. The method of claim 53, wherein the control is a blank control.

57. The method of claim 53, wherein the control is an absorbent material control.

58. The method of claim 53, wherein measuring the amount of free TMA in the withdrawn portion of the gas headspace comprises:

passing the withdrawn portion of the gas headspace through a stationary phase loaded with a colorimetric label that changes color upon contact with TMA; and

measuring an amount of color change in the stationary phase in response to passing the withdrawn portion of the gas headspace through the stationary phase.

59. A method of manufacturing an absorbent article, the method comprising:

preparing an absorbent material comprising a fibrous matrix and a carboxylic acid coupled to the fibrous matrix; and

a fluid permeable topsheet and a fluid impermeable backsheet are coupled to the absorbent material.

60. The method of claim 59, wherein the absorbent material is disposed between the fluid permeable topsheet and the fluid impermeable backsheet.

61. The method according to claim 59, wherein the absorbent material is disposed within the fluid permeable topsheet.

62. The method according to claim 59, wherein the absorbent article is a feminine hygiene product.

63. The method of claim 62, wherein the feminine hygiene product is selected from the group consisting of pantiliners, sanitary napkins, postpartum absorbent pads, light incontinence pads, interlabial pads, and disposable menstrual protective undergarments.

64. The method of any one of claims 62 or 63, wherein the feminine hygiene product is configured to be worn externally.

65. The method of any of claims 62-64, wherein the feminine hygiene product is not configured to be worn internally.

66. The method of claim 59, wherein the absorbent article is a meat packaging pad.

67. The method of claim 59, wherein the absorbent article is according to any one of claims 36-52.