CN101828751A

CN101828751A - Method for drying natto

Info

Publication number: CN101828751A
Application number: CN 201010124650
Authority: CN
Inventors: 韩慧; 徐勇虎; 刘晓鸥; 国华; 李睿颖; 许勤虎
Original assignee: TIANJIN SF-BIO INDUSTRIAL BIO-TECH Co Ltd
Current assignee: Tianjin testing & Certification Technology Co., Ltd.
Priority date: 2010-03-16
Filing date: 2010-03-16
Publication date: 2010-09-15
Anticipated expiration: 2030-03-16
Also published as: CN101828751B

Abstract

The invention relates to a method for drying natto. The method is implemented by the following steps of: directly and uniformly coating fermented natto material on a conveyer belt of a microwave heating tunnel dryer or in a tray of a microwave drying box and controlling the thickness of the natto material within the range from 0.1 to 5cm, wherein the running speed of the conveyer belt of the tunnel dryer is 0.01 to 1m/min, the power of the microwave is 0.5 to 150kw, the density of the electromagnetic wave is 0.5 to 20kw/m<3> and the irradiation energy is 100 to 4,000J/g; meanwhile, introducing hot dry air into the conveyer belt of the tunnel dryer or the bottom of the microwave drying box to quicken the drying and pumping away the air with high moisture from the conveyer belt or the space above the drying box so as to prevent the material from absorbing the moisture, wherein the drying temperature of the surface of the material is kept at between 40 and 60 DEG C and the drying time is 5 to 60 min; and finally collecting, crushing, drying and sieving the natto by a conventional method to obtain the natto powder product. The method can keep the active ingredient of the natto and be used for industrial production, and has simple process and obvious effect.

Description

The drying means of natto

Technical field

The present invention relates to a kind of drying means of food, particularly a kind of drying means of natto.

Background technology

Natto is initiated at the fermented soya bean of China, imports Japan about Nara, safety epoch into by the buddhist monk greatly.Japan claimed once also that natto was " fermented soya beans, salted or other wise ", after natto imports Japan into, had further developed natto according to the natural conditions and social customs of a place of Japan.In recent years, learnt through physician, physiologist's research of Japan that the protein of soybean had indissolubility, and after making natto, become solvable and generation amino acid, and non-existent various ferment can help stomach to digest and assimilate because Bacillus natto produces in the raw material.The composition of natto is: moisture 61.8%, crude protein 19.26%, crude fat 8.17%, carbohydrate 6.09%, crude fibre 2.2%, ash content 1.86%, as vegetable food, crude protein, fat are the abundantest.Natto is the high protein nourishing food, and the alcohol that contains in the natto is plain, can get rid of part cholesterol in the body, the interior acidifying type lipid of decomposer after eating, and makes abnormal blood pressure recover normal.Studies show that multiple function factors such as the main Nattokinase, natto isoflavones, soap green grass or young crops element, farnoquinone with wherein of the health care of natto are relevant.It is blue or green plain to be rich in soap in the natto, can improve constipation, reduces blood fat, and prevention colorectal cancer, reduction cholesterol, softening blood vessel, prevention hypertension and artery sclerosis suppress functions such as AIDS virus; Contain free isoflavone like substance and multiple enzyme in the natto to the human body beneficial, as superoxide dismutase, catalase, protease, amylase, lipase etc., they can remove carcinogen in the body, improve memory, protect that liver is improved looks, delays senility etc. positive effect, and can improve the digestibility of food; Take in the Bacillus natto that lives and can regulate the gut flora balance, prevention dysentery, enteritis and constipation, its effect is better than lactobacillus micro-ecological preparation commonly used now in some aspects; The emplastic that the natto fermentation produces on the gastrointestinal tract mucous surface that is covered, thereby can be protected stomach and intestine, can alleviate drunk effect when drinking.

Because the active material-Nattokinase in the natto will lose activity more than 60 ℃, so the drying means of natto only limits to two kinds of freeze drying and spray-dryings at present.Though the Bacillus natto in the natto is a brood cell bacterium, heat-resisting relatively, through after the spray-drying, the thalline death rate reaches more than 40%, must select for use suitable protective agent that it is protected; Though and freeze drying thalline survival rate is very high, the energy that consumes in the freezing dry process is bigger, and production capacity is little, and equipment cost and carrying cost are all very high, and this has limited the application of Freeze Drying Technique in industrial production to a great extent.

Therefore, provide a kind of drying means that not only can keep active component but also can be applicable to industrial natto, become one of these those skilled in the art problem anxious to be addressed.

Summary of the invention

The objective of the invention is to overcome above-mentioned weak point, provide a kind of and effectively improve the quality of products, technology is simple, the drying means of obvious results natto.

Implementation of the present invention is as follows for achieving the above object: a kind of drying means of natto, it is characterized in that implementation step is as follows: the natto material that ferments is directly evenly coated in microwave heating tunnel's formula drying machine conveyer belt or the microwave drying oven pallet, the material of canal drier conveyer belt or microwave drying oven pallet is a polytetrafluoroethylene (PTFE), and the material bed thickness of control natto is at 0.1-5cm; The canal drier conveyer belt speed of service is 0.01-1m/min, and the power of microwave is 0.5-150kw, electromagnetic wave density 0.5-20kw/m ³, irradiation energy 100-4000J/g; In addition, at irradiation energy one regularly, general microwave power height, material is lighter, and heat time heating time is shorter, can make the abundant explosion puffing drying of material; According to character such as the water content of microwave drying material, viscosity, film formings, the mode of dry air of taking to feed in canal drier conveyer belt or microwave drying oven bottom heat in drying simultaneously is accelerating rate of drying, and simultaneously that humidity is bigger air is taken away to prevent the material moisture absorption from conveyer belt or drying box top; Material surface baking temperature remains on 40-60 ℃, drying time 5-60min; Collect routinely at last, pulverize, after dry, the screening, obtain the natto powder product.

What the present invention adopted is micro-wave drying method, and microwave is that frequency is 3.0 * 10 between wavelength 1mm-0.5m ²-3.0 * 10 ⁵MHz is a kind of electromagnetic wave with penetrability.Allowing to use specific frequency at industrial, is 915MHz and 2450MHz in China.Microwave has been used for fields such as heating, drying, desinsection, sterilization, medical treatment to the end of the sixties.During conventional the heating, material surface temperature is low, the internal temperature height, temperature distributing disproportionation is unfavorable for that moisture evaporates rapidly, heats together and heating using microwave is the inside and outside, and because surface heat radiation easily, internal temperature is higher than the outside like this, and the thermograde direction is identical with gradation of moisture direction, mass transfer is consistent with the heat transfer direction, impel the internal moisture rapid evaporation, form the internal pressure gradient, make moisture be diffused into the surface very soon and vapor away, make shorten dramatically drying time, guarantee product quality.What microwave drying was adopted is electric energy, easy and simple to handle, small investment, be well suited for need be very long the product that could remove moisture content drying time or to the very sensitive product of temperature.Say that generally microwave drying can combine with convection current or vacuum drying and reaches the purpose that cuts down the consumption of energy.

The invention has the beneficial effects as follows: because the applied straticulation of natto material after handling, just enlarged the contact-making surface of material and extraneous medium, make water evaporates very fast, this has just been avoided temperature too high so that influence product quality, the dried natto product of the present invention thalline survival rate height, the functional preservation of Nattokinase isoreactivity material promoted product quality greatly.Microwave drying simultaneously greatly reduces energy consumption, makes operating cost and production cost reduce greatly; Its technology is simple, and is easy to operate, and the effect highly significant is more suitable for industrialized production.

The specific embodiment

Below in conjunction with preferred embodiment, to according to the specific embodiment provided by the invention, details are as follows for feature:

Embodiment 1

The natto that ferments is directly evenly coated on the conveyer belt of microwave heating tunnel's formula drying machine, and the material of canal drier conveyer belt is polytetrafluoroethylene (PTFE) or other nontoxic heat proof material, and the material bed THICKNESS CONTROL of natto is at 2cm; The canal drier conveyer belt speed of service is 0.2m/min, and the power of microwave is 60kw, electromagnetic wave density 10kw/m ³, irradiation energy 1200J/g; Microwave wavelength is controlled between the 1mm-0.5m, and frequency is 3.0 * 10 ²-3.0 * 10 ⁵MHz; In addition, at irradiation energy one regularly, general microwave power height, material is lighter, and heat time heating time is shorter, can make the abundant explosion puffing drying of material; According to character such as the water content of microwave drying material, viscosity, film formings, also the mode of dry air that can take to feed in conveyer belt bottom heat simultaneously in drying to be accelerating rate of drying, and the air that humidity is bigger is taken away to prevent the material moisture absorption from the conveyer belt top; Material surface baking temperature remains on 42 ℃, drying time 15-25min; Collect routinely at last, pulverize, after dry, the screening, obtain the natto powder product, realize producing continuously.

Embodiment 2

The natto that ferments is directly evenly coated in the pallet of microwave drying oven, and the material of microwave drying oven pallet is polytetrafluoroethylene (PTFE) or other nontoxic heat proof material, and its material bed THICKNESS CONTROL is at 4cm; The power of microwave is 80kw, electromagnetic wave density 12kw/m ³, irradiation energy 1500J/g; Microwave wavelength is controlled between the 1mm-0.5m, and frequency is 3.0 * 10 ²-3.0 * 10 ⁵MHz; In addition, at irradiation energy one regularly, general microwave power height, material is lighter, and heat time heating time is shorter, can make the abundant explosion puffing drying of material; According to character such as the water content of microwave drying material, viscosity, film formings, also the mode of dry air that can take to feed in microwave drying oven bottom heat simultaneously in drying to be accelerating rate of drying, and the air that humidity is bigger is taken away to prevent the material moisture absorption from the microwave drying oven top; Material surface baking temperature remains on 58 ℃, drying time 10-15min; Collect routinely at last, pulverize, after dry, the screening, obtain the natto powder product, realize producing continuously.

Below enumerate a plurality of embodiment main control parameters:

Natto material surface baking temperature remains on 40-60 ℃, is controlled to be 5-60min drying time.

If then do not comprise the setting of line speed parameter when adopting microwave drying oven to carry out drying.

The dried natto product of the present invention thalline survival rate height, the functional preservation of Nattokinase isoreactivity material promoted product quality greatly.

Operation principle: microwave is a kind of electromagnetic wave, can produce the electromagnetic field of high frequency.Dielectric material is made up of polar molecule and nonpolar molecule, under electromagnetic field effect, polar molecule is from the polarity oriented of original random distribution state shift according to electric field, thereby causes the motion of molecule to make that with mutual friction produce power mutually medium temperature improves constantly under the high-frequency electromagnetic field action.Because the very high frequency of electromagnetic field, the frequency of polar molecule vibration is very big, so the heat that produces is very high.When heating using microwave was applied to food industry, under the high-frequency electromagnetic field action, the polar molecule in the food (hydrone) absorbed microwave energy and produces heat, made that food heats rapidly, drying.

Above-mentioned with reference to embodiment to the detailed description that the drying means of this natto carries out, be illustrative rather than determinate; Therefore in the variation and the modification that do not break away under the general plotting of the present invention, should belong within protection scope of the present invention.

Claims

1. the drying means of a natto is characterized in that implementation step is as follows: the natto material that ferments is directly evenly coated in microwave heating tunnel's formula drying machine conveyer belt or the microwave drying oven pallet, controlled the material bed thickness of natto at 0.1-5cm; The canal drier conveyer belt speed of service is 0.01-1m/min, and the power of microwave is 0.5-150kw, electromagnetic wave density 0.5-20kw/m ³, irradiation energy 100-4000J/g; Material surface baking temperature remains on 40-60 ℃, drying time 5-60min; Collect routinely at last, pulverize, after dry, the screening, obtain the natto powder product.