WO2021221511A1

WO2021221511A1 - Fries for air fryer and oven

Info

Publication number: WO2021221511A1
Application number: PCT/NL2021/050287
Authority: WO
Inventors: Erik De Been
Original assignee: Lambweston / Meijer V.O.F.
Priority date: 2020-05-01
Filing date: 2021-05-03
Publication date: 2021-11-04
Also published as: EP4142516A1

Abstract

The present invention relates to potato fries prepared with oven technology, in particular a hot air convection system such as an air fryer or oven and made from waxy potatoes. Optionally the fries comprise a coating. According to the invention the waxy potatoes are of a variety having an underwater weight of more than 340 g/5 kg, in particular a variety selected from the group consisting of Allians, Glorietta, Bernina, Belana, Otolia, Regina, Annabelle, Actrice, Princess, Jazzy, Musica, preferably Regina. The invention further relates to a method for preparing potato fries, comprising: a) cutting raw potatoes into strips; b) blanching the strips; c) optionally coating the potato strips; d) par-frying the potato strips to obtain par-fried potato fries; and e) frying the par-fried potato fries with oven technology, in particular in an air fryer or hot air convection oven, wherein the potatoes are waxy potatoes.

Description

FRIES FOR AIR FRYER AND OVEN

The present invention relates to potato fries for that are prepared by other preparation methods than deep-frying, in particular by means of oven technology, such as found in a hot air convection oven and air fryer. The invention further relates to a method of preparing these potato fries.

Nowadays there is an increasing demand for healthier food products. Traditionally, potato fries are not considered to contribute to a sensible lifestyle. Potato fries are usually high in fat content as a result of frying them in oil. Therefore, potato fries are nowadays more often fried in a hot air convection system, in particular an oven or an air fryer. Air fryers use circulating hot air to cook food that would normally be fried in oil. The air fryer often also radiates heat from a heating element near the food, thus cooking it more efficiently. A fan is generally used to circulate hot air around the food.

Potato fries should have a crispy outer layer and a fluffy interior for an optimal taste. The crispy layer is the result of browning reactions of two kinds. The Maillard reaction is a chemical reaction between amino acids and reducing sugars that gives browned food its flavor. Traditional frying methods induce the Maillard effect by completely submerging foods in hot oil. In the other browning reaction, called caramelization, sugars break down and chemically transform into complex brown-colored substances. The Maillard reaction requires temperatures of between about 140-165°C, while caramelization temperatures depend on the sugar being caramelized and range from 110-180°C.

In traditional potato fries, these two reactions are induced by submerging the potato fries in hot oil in a deep fryer. The air fryer works by coating the desired food in a thin layer of oil while circulating air heated up to 200 °C to initiate the reaction. By doing this, 70% to 80% less oil is used than a traditional deep fryer. Potato fries are first pre -fried and subsequently finish-fried.

It is standard practice in the art to prepare fries from mealy/floury potatoes, because these give, when double fried, a crispy exterior and soft/floury interior.

However, finish-frying traditional potato fries in an oven or an air fryer leads to potato fries that become dry and chewy and lose their crispiness and crunchiness and burn easily.

It is therefore an object of the present invention to provide potato fries that are more suitable for alternative and healthier cooking methods, such as cooking methods that are based on oven technology, in particular on hot air convection, like the oven and air fryer, and are crispy and crunchy on the outside with a soft creamy interior. In the research leading to the invention it was found that potato fries that are prepared in the oven or air fryer and still maintain a crispy outside and are fluffy and creamy on the inside can be obtained by using fries cut from waxy potatoes.

The invention thus relates to potato fries prepared by oven technology and made from waxy potatoes. The oven technology comprises in particular a hot air convection system, more in particular an air fryer or hot air convection oven.

Waxy potatoes have smooth, dense flesh that holds its shape well when cooked. Waxy potatoes tend to have a thin skin, high water content and often contain lower levels of starch compared to floury potato.

In the field of potato breeding, waxy potatoes are distinguished from floury potatoes by determining their cooking type, which is a classification system for cooked potato texture based on a sensory evaluation established by the European Association of Potato Research (EARP) and described in Winiger, F.A. & Ludwig, J.W. (Potato Res. 17 (1974): 434-465). The following descriptors are used in the sensory evaluation: mealiness, consistency, sloughing, moistness and structure. Before start of the sensory evaluation the potatoes are peeled and steam-cooked (100°C/10⁵ Pa) during 30-35 minutes.

Mealiness is defined as the easiness of cooked potato tissue to disintegrate (either with a fork or during consumption) into clusters of cells, without fracturing cells.

Consistency refers to the resistance of cooked potato tissue to mashing/disintegration (either with a fork or during consumption).

Sloughing refers to the loosening of the outer layers of the cooked potato.

Moistness comprises the moistness/dryness of potato tissue perceived during consumption.

Structure refers to the presence of granules and vascular bundles in cooked potato tissue perceived during consumption.

According to this system potato varieties are classified into cooking type groups A, B, C and D:

Cooking type A comprises solid salad potatoes. They should not disintegrate upon cooking and are sticky, they are not floury, but moist and fine-grained. The visage is pure, the starch content is low. Potatoes of this type are particularly suitable for potato salad, but can also be used for various other dishes.

Cooking type B comprises fairly firm potatoes suitable for many purposes. They do not open up much when cooked and remain moderately firm. They are slightly floury, not very moist and quite fine-grained. Type B varieties are among the preferred table potatoes.

Cooking type C comprises floury potatoes. They generally spring open when cooked, are rather soft, floury and rather dry in the meat. The structure is quite coarse and the taste is strong. Cooking type D comprises highly floury potatoes. Representatives of this type completely disintegrate upon cooking and are either soft or unevenly hard in the meat. They are also very floury, dry and rough in taste.

Some types or samples cannot be classified in a pure cooking type, but rather form transition types. Cooking type BC means that the characteristics of type B predominate. If, on the other hand, the designation CB is used, the emphasis is on cooking type C.

Figure 1 shows potatoes of the four different cooking types.

The waxy potatoes used in the invention belong to any of the groups A, AB or B and have preferably cooking type A or AB. Traditional potato fries are made from mealy potatoes, i.e. potatoes with cooking type CB, C etc.

In order to further improve the crispiness of the outside of the potato fries, the fries comprise preferably a coating. This can be any standard clear coat composition that is usually applied to potato fries. A clear coat composition typically comprises water and a farinaceous component, i.e. comprising some form of starch. The clear coat composition must not influence the flavor or appearance of the fries after they have been fried. In one embodiment, the coating comprises predominantly starch. Coatings are usually clear and also increase the holding time. Furthermore, they prevent the waxy potato strips from burning.

The clear coat composition suitably comprises one or more of the ingredients selected from the group consisting of native potato starch, modified potato starch, in particular distarch phosphate (E1412), tapioca starch, corn starch, rice flour, dextrin, leavening agent, thickening agent. Examples of a suitable clear coat composition for use in the invention are disclosed in US- 6,022,569, US-5,059,435, WO-200028828.

Preferably, the waxy potatoes are of a variety having an underwater weight of more than 340 g/5 kg, preferably more than 350 g/5kg, more preferably more than 360 g/5kg, even more preferably more than 370 g/5kg and most preferably 380 g/5 kg or more. It was found that with this last type of potatoes a particularly good result could be obtained. Examples of varieties of waxy potatoes that are suitable for use in the method of the invention are listed in Table 1 below.

Table 1

Suitable waxy varieties for use in the invention

The fries of the invention are prepared by means of oven technology. An oven is a tool which is used to expose materials to a hot environment. Ovens comprise a closed hollow chamber and a mechanism of heating the chamber in a controlled way. Sometimes ovens for potato fries are semi-closed to accommodate a conveyer belt to transport the fries through the oven in a continuous frying process.

The heating mechanisms used in ovens can be diverse. Hot air convection is a well known heating mechanism that is used in hot air convection ovens and air fryers. Other heat transfer mechanisms include thermal radiation, conduction, other forms of convection, such as impingement, and (superheated) steam injection. Some of these may be combined with infrared heating or electromagnetic waves, such as, microwaves and/or radio waves, in hybrid ovens. An impingement oven is a type of convection oven that not only circulates hot air around the food, but does so with force to penetrate the layer of cold air that often surrounds food. This way the food can cook faster. All these different oven technologies are suitable for finish-frying the potato fries of the invention. Hot air convection systems are preferred. The air fryer and hot air convection oven are most preferred.

The present invention further relates to a method for preparing potato fries, comprising: a) cutting raw potatoes into strips; b) blanching the potato strips; c) optionally coating the potato strips; d) par-frying the potato strips to obtain pre -fried potato fries; and e) finish-frying the pre -fried potato fries with oven technology, in particular a hot air convection system, in particular an air fryer or oven, wherein the potatoes are waxy potatoes.

The potato strips are suitably blanched for a relatively long time, in particular between 1 and 30 minutes, preferably between 10 and 25 minutes, more preferably between 15 and 20 minutes, and most preferably between 16 and 18 minutes. The blanching temperature lies between 65 and 100°C, preferably between 75 and 90°C and more preferably between 80 and 85°C. In one embodiment, the blanching is performed for 1 to 30 minutes at 65-100°C, preferably for 10-25 minutes at 75-90°C, more preferably for 16 to 18 minutes at 80 to 85°C. Alternatively, a shorter blanching time may be compensated by a longer par-frying time.

It is possible to par-fry the potato strips in oil or fat. Par-frying in oil is found to be not detrimental to the quality of the finished fries with respect to crispiness and crunchiness and fluffy interior.

Par-frying the potato fries can be done in any food-grade type of vegetable or animal oil or fat. Suitable oils are sunflower oil and canola oil.

In one embodiment, the fries are deep-frozen after par-frying. Steps d) and e) are then not performed one after the other but with some time in between. In this time, the pre-fried potato fries are frozen and transported to directly to a customer or a retail outlet, where they can remain for an undefined period of time. After being bought by a consumer the frozen fries can even end up in the consumer’s freezer before being finish-fried. The method is intended to also encompass the situation in which step e) is performed much later than steps a) to d) and thus also covers a method wherein the fries are prepared up to and including the deep-freezing step and are only intended to be at some point subjected to step e).

The present invention will be further illustrated in the example.

EXAMPLE

Sensory assessment of potato fries of the invention compared to traditional potato fries

Potatoes of varieties Regina were cut into 9x9 mm strips and blanched at 85°C during 16 minutes. The strips were then coated with a standard batter, par-fried during 60 seconds at 175°C and deep-frozen at -18°C.

The sensory characteristics of the potato fries of the invention were compared by a sensory panel to a number of commercially available potato fries for air fryer listed in Table 2.

Table 2

Overview of products used in the panel test

The sensory panel for this test consisted of 13 panelists. All panelists are employees of Lamb Weston / Meijer v.o.f., who have been selected based on their ability to detect basic flavours and odours, their ability to verbally express themselves and their ability to learn new attributes. In addition, these panellists have been trained in the Lamb Weston / Meijer vocabulary for fries and iconic shapes and different sensory testing methods.

All products were stored at -18°C until cooking. Each product was reconstituted in a Philips Airfryer XL according to Table 3. The products were placed in boat cups labeled with 3- digit codes directly after cooking to be served to the panellists with a temperature slightly above eating temperature.

Table 3

Overview of preparation instruction(s) on pack and conditions used in practice

* The preparation conditions used in the test differed from the instructions on pack. As indicated on pack, the instructions are guidelines while each air fryer is different. In tests prior to the panel test it became clear the instructions used were needed to fully cook the product in the air fryers used in the test.

** To prepare this product, a temperature of 200°C had been used accidentally during the test instead of the indicated 180°C.

The panellists were seated in sensory booths with appropriate daylight lighting and a slight over-pressure to prevent contaminating odours to enter the booths. The products were served with 3-digit codes following semi-monadic presentation. The data has been collected using EyeQuestion® software (version 5.0.3.5). Each panelist had approximately 9 minutes to evaluate each product. Within this time frame they had to score the attributes by placing a cross on a line scale. The placing of this cross is translated into an exact score between 0 and 100. The panelists had no possibility to look back at the scores of previous products. Their judgement was therefore based on their internal reference framework and the memory of the previous products.

Descriptive profiling maps the nature and the intensity of different product characteristics. This technique is used to compare products at specific attributes or to create a complete sensory profile of a product. There are different methods that can be used to perform a descriptive sensory research. Within this test the Quantitative Descriptive Analysis (QDA) methodology has been used. This method concerns the use of a vocabulary, which is the basic for agreement between the panellists.

This vocabulary contains the instructions that need to be followed for the evaluation of a number of attributes. For crispiness for example, the panelists are instructed to evaluate this after taking a bite with the incisors. While for crunchiness the panelists are instructed to evaluate this after chewing between the molars. Next to the instructions, the vocabulary contains a definition for each attribute including the anchors of the scale. These anchors are ‘not’ or ‘no’ on the left side of the scale (score of 0) and ‘very’ or ‘large’ on the right side of the scale (score of 100).

The attributes that distinguish the potato fries of the invention from the comparison fries are listed in Table 4 below.

Table 4

Sensory attributes

Regarding the external texture of the products it becomes clear the fries of the invention have resulted in the highest score on crispiness, contrast and crunchiness (bold typeface), all desired attributes. The fries of the invention score the lowest on chewiness, internal firmness and dryness (italic typeface), which are all unfavorable attributes.

The results are further illustrated in Figure 2.

Claims

1. Potato fries prepared with oven technology, and made from waxy potatoes.

2. Potato fries as claimed in claim 1 , wherein the waxy potatoes belong to cooking type A, AB or B.

3. Potato fries as claimed in claim 1 or 2, wherein the oven technology comprises a hot air convection oven or air fryer.

4. Potato fries as claimed in any one of the claims 1 to 3, wherein the fries comprise a coating.

5. Potato fries as claimed in claim 4, wherein the coating comprises a clear coat composition.

6. Potato fries as claimed in claim 5, wherein the clear coat composition comprises one or more of the ingredients selected from the group consisting of native potato starch, modified potato starch, in particular distarch phosphate (E1412), tapioca starch, corn starch, rice flour, dextrin, leavening agent, thickening agent.

7. Potato fries as claimed in any one of the claims 1 to 6, wherein the waxy potatoes are of a variety having an underwater weight of more than 340 g/5 kg.

8. Potato fries as claimed in claim 6, wherein the underwater weight is 380 g/5 kg or more.

9. Potato fries as claimed in any one of the claims 1-8, wherein the waxy potato is a variety selected from the group consisting of Allians, Glorietta, Bernina, Belana, Otolia, Regina, Annabelle, Actrice, Princess, Jazzy, Musica, Nicola.

10. Method of preparing potato fries, comprising: a) cutting raw potatoes into strips; b) blanching the strip; c) optionally coating the potato strips; d) par-frying the potato strips to obtain pre -fried potato fries; and e) finish-frying the pre -fried potato fries by oven technology, in particular in a hot air convection system, more in particular in an air fryer or oven, wherein the potatoes are waxy potatoes.

11. The method as claimed in claim 10, wherein the potato strips are par-fried in oil or fat.

12. The method as claimed in claim 10 or 11, wherein the fries are deep-frozen after par- frying.

13. The method as claimed in claim 10, 11 or 12, wherein the coating is a standard starch- based coating.

14. The method of any one of the claims 10-13, wherein the waxy potato is a variety selected from the group consisting of Allians, Glorietta, Bernina, Belana, Otolia, Regina, Annabelle, Actrice, Princess, Jazzy, Musica, Nicola.

15. The method as claimed in any one of the claims 10-14, wherein the air fryer or oven is combined with one or more other techniques, such as microwave and infrared heating, impingement.