EP3829323A1

EP3829323A1 - Method for producing gluten-free flour made of apple pomace

Info

Publication number: EP3829323A1
Application number: EP19762868.8A
Authority: EP
Inventors: Snezana ZLATANOVIC; Stanislava GORJANOVIC; Sanja OSTOJIC; Darko MICIC; Ferenc PASTOR; Ana KALUSEVIC; Jovanka LALICIC-PETRONIJEVIC
Original assignee: Institut Za Opstu I Fizicku Hemiju AD
Current assignee: Institut Za Opstu I Fizicku Hemiju AD
Priority date: 2018-08-03
Filing date: 2019-06-13
Publication date: 2021-06-09
Also published as: WO2020027683A1; RS63010B1; RS20180918A1

Abstract

The present invention relates to the industrial process for the production of apple pomace flour (peel, seed, stem and pulp) after juicing. Dry apple pomace with low water content (4-6%) and activity (0.2 - 0.4) obtained by dehydration (chamber temperature of 40 - 55 °C, time 6 - 8h) allows grinding without agglutination. Grinding affords permanent, non-hygroscopic Apple Pomace Flour (APF). Flour has distinct apple flavor and scent, high content of dietary fibers (DF) (35 - 50%) and antioxidants (AO), as well as high Water Holding Capacity (5.4 - 6.5 g/g) and Oil Holding Capacity (1.2 - 1.7 g/g). Used as an ingredient in gluten-free or functional products that do not comprise or have a lower percentage of allergens for individuals intolerant to gluten, APF compensates for the lack of DF and antioxidants in the diet. It is used also as a dietary preparation, whose optimal daily dose is determined by an in vivo study, confirming a positive effect on regulation of glucose and lipid metabolism.

Description

METHOD FOR PRODUCING GLUTEN-FREE FLOUR MADE OF APPLE

POMACE

Technical field

The present invention belongs to the field of food technology.

Technical problem

In apple pomace, containing the peel, seeds, stem as well as the pulp, which is the by product in the fruit juice industry (25 wt% of the starting apple weight), remain the majority of the nutritive ingredients of an apple (biologically active phenols, dietary fibers, vitamins, minerals etc.). Only 3-10% of the overall antioxidative activity of an apple remains in the apple juice (Djilas et al, 2009, Rana et al, 2015). Phenols and dietary fibers of the apple pomace exhibit numerous beneficial health effects, such as antioxidative, cardioprotective, antidiabetic, and antilipemic properties, and they improve the function of the gastrointestinal tract (GIT) (Skinner et al, 2018). Due to its nutritive properties and excellent technofunctional properties (swelling properties, high water and oil holding capacity, positive effect on the texture and other sensorial properties of food), apple pomace has large potential to be used as an ingredient of functional products with improved nutritive properties and taste (Reis, Rai and Abu-Ghannam, 2014). Production of food with improved nutritive properties is only one important aspect of the development of non-waste technology, i.e. circular economy development, applied in the apple juice production industry, which globally generates 70 million tons of apple pomace per year (data from 2015) (Yates et al, 2017).

However, apple pomace also contains 75 wt % water, which shall be removed during the process of industrial production, by an energy saving method, which should enable preserving all nutritive and functional properties of apple pomace. Thus, it is an aim to effectively use apple pomace and produce high quality products with improved nutritive properties, by preserving all nutritive properties, biological activity of phenols and dietary fibers, as well as preserving all functional properties of apple pomace. So far, this problem has been solved by the lyophilization process, which is effective for preserving phenols and dietary fibers. However, this process is extremely energy intensive and lasts very long (Rana et al, 2015). The technical problem of the present invention is how to provide an energy-efficient industrial process for the drying of apple pomace, i.e. production of apple pomace flour (APF), wherein the apple pomace contains seeds and stem, while the content of biologically active antioxidants and dietary fibers, as well as antidiabetic and antilipemic activity of the apple pomace flour remains preserved. The method of the present invention shall enable preserving the flavor, nutritive and functional properties of fresh apple pomace and obtaining natural, gluten-free flour, which does not contain antinutritive factors (e.g. gluten, phytic acid), artificial flavors or colors, preservatives, or any kind of additives, while at the same time by using the suggested method, no harmful substances are produced.

By using the method according to the present invention, the problem of deficiency of dietary fibers and antioxidants in regular food is also solved. The flour obtained by the method described herein may be used for obtaining confectionery and bakery products, i.e. obtaining functional products enriched with dietary fibers and antioxidants, and with very low gluten or gluten-free.

The method of the present invention enables the production of gluten-free products from pure apple pomace flour, as well as from this flour mixed with other types of gluten-free flour. The present disclosure also suggests optimal doses of the apple pomace flour, to be used as a dietary preparation, which is, as shown by in vivo study, proven to have an effect on the regulation of glucose and lipid metabolism.

Background

The prior art describes several ways of removing water content from apple pomace, e.g. sun drying, conventional drying with hot air and steam, as described in CN106382791. The drawback of the conventional drying methods is disturbed structure and function of the biologically active ingredients, i.e. loss of nutritional and functional values due to high temperature exposure (above 100 °C).

Complete preservation of the nutritive value, antioxidants and dietary fibers, as well as preservation of the functional properties of apple pomace is until now reached only by lyophilization. The drawback of this method is the extremely long duration of the process and high energy consumption (Rana et al. 2015). Due to this disadvantage, lyophilization has been used so far only for drying apple pomace for research purposes in the laboratory. In addition, by using the method according to the present invention, water content is reduced to J

4-6 wt% for only 6h, while by using the lyophilization method, in order to achieve the same effect, it is necessary to perform the treatment for more than 24h (Jung et al. 20l5a).

Currently there are available products, such as powders, obtained from whole apples which contain a lot of sugar, powders obtained from the peel of organic apples, and powders containing dietary fibers isolated from apple pomace. There is also protein-rich flour obtained from apple pomace by fermentation, as disclosed in WO 2018/101844. However, this flour obtained as described in this document is significantly different from the starting material, i.e. it contains the fermentation products and microorganisms. On the other hand, the flour obtained as described by the present invention contains ingredients identical to the squeezed fresh apple. The commercially available product, Apple egg, is the most similar product when compared with the apple pomace flour obtained as described by the present invention. Namely, Apple egg is a product which also contains apple pomace with the addition of pectin. Thus, Apple egg was used for comparison analysis, i.e. Apple egg was analyzed in parallel with various samples of flour obtained as described by the present invention. Our results indicated that flour obtained from apple pomace as suggested in the present disclosure, exhibit higher Oil Holding Capacity (OHC) as well as Water Holding Capacity (WHC), significantly higher total content of phenolics (TPC) and flavonoids (TFC), and more prominent antioxidative (AO) activity when compared with Apple egg.

As suggested in the prior art, apple pomace may be used as an additive in food products, e.g. for partial replacement of regular flour in confectionary and bakery products. Generally, a portion of up to 30 wt % of regular flour has been replaced by dried apple pomace. It has been demonstrated that by partial replacement of wheat flour by dried apple pomace in an amount of 5, 10 and 15 wt % (Rupasinghe et al., 2008), it would be possible to produce muffins, cookies and bakery products which exhibit pleasant sensorial properties. The addition of apple pomace in an amount of 17, 22 and 28 wt % to snack products made of corn does not in any way disturb the texture, while it provides fruit flavor and at the same time increases the content of dietary fibers and antioxidants (Karkle et al., 2012). Flour obtained as described by the present invention may replace up to 75 wt % of wheat flour contained in cookies (under industrial conditions). Similarly, it has been demonstrated that using only apple pomace flour, gluten-free products of acceptable sensorial properties may be obtained.

Disclosure of Invention The present invention discloses a method for producing stable apple pomace flour, with high content of dietary fibers and antioxidant, antidiabetic and antilipemic effect, which is intended for use as a dietary preparation or an ingredient of functional food, such as fiber- rich food and food with powerful antioxidative activity. Furthermore, these food products are characterized by low gluten or gluten-free content and are made of pure apple pomace flour or a mixture of apple pomace flour with other kinds of gluten-free flours. The present disclosure also includes the results of an in vivo study, which unambiguously confirmed the positive effect of apple pomace flour on glucose and lipids metabolisms regulation. The present invention also discloses the optimal daily dose of the apple pomace flour as a dietary preparation.

The method according to the present invention includes the industrial dehydration of apple pomace obtained by pressing apples, without the use of any enzymes. The method as disclosed includes aseptic takeover of fresh wet apple pomace from an apple juice producer, transportation to dehydrator, dehydration of wet apple pomace containing about 75 wt % of water, grinding of dehydrated pomace containing 4 - 6 wt % of water and 0.2 - 0.4 water activity, to obtain flour having particles lower than 300 pm in size, and finally, packing of apple pomace flour in multilayer natron jackets and storing.

Apple pomace flour obtained by the method according to the present invention was analyzed by in vitro and in vivo studies, which confirmed the content and effect of biologically active ingredients of apple pomace flour. Specifically, these studies have shown that apple pomace flour according to the present invention may be used as a dietary preparation, i.e. dietary supplement and as a component of functional food. Based on the results of these studies, it may be concluded that by consuming apple pomace flour, either in the form of a dietary preparation or a component of a food product, a lack of dietary fibers and antioxidants in the diet may be compensated. By regular uptake of apple pomace flour, the metabolism of glucose and lipids may be regulated but also this may prevent metabolic disorders, above all diabetes and arteriosclerosis, and consequently, cardiovascular diseases. Moreover, the apple pomace flour containing a high content of dietary fibers and antioxidants, improves the intestinal peristalsis and intestinal microflora, i.e. enables regular functioning of GIT.

The present invention discloses also the results of studies performed in order to elucidate the content and sensorial properties of cookies which are characterized by 75 wt% of wheat flour being replaced by apple pomace flour. These results confirmed that the cookies exhibit preferable texture and apple flavor, significantly higher content of biologically active ingredients, and prolonged storage time, when compared with the control. Moreover, the study indicated that cookies and muffins obtained from pure apple pomace flour and also from a mixture of apple pomace flour and other kinds of gluten-free flours, exhibit preferable sensorial properties.

Best Modes for Carrying Out of the Invention

The present invention provides the method for dehydration of the whole apple pomace (without prior exclusion of seeds and stem), including subsequent grinding of dehydrated pomace to obtain apple pomace flour. Apple pomace flour according to the present invention is intended for use as a complete or partial replacement for cereal flour and pseudocereal flour, i.e. for obtaining enriched and gluten-free products (either independently or in combination with other gluten-free flours). According to the present invention, apple pomace flour may further be used as a dietary preparation wherein the optimal daily intake is confirmed by an in vivo study.

The method for producing gluten-free apple pomace flour includes the following steps:

• Aseptic takeover of fresh wet apple pomace containing the peel, seeds, stem and pulp. The pomace is characterized by 75 wt % of water and is obtained under industrial conditions by apple pressing, with no enzymatic activity involved, and according to the standards of Hazard Analysis and Critical Control Points. Inserting of apple pomace in a dehydrator, preferably, inserting of apple pomace placed on perforated plates in a preheated dehydrator.

• Dehydration of wet apple pomace at a temperature below 55°C, preferably between 45 and 55 °C, for 4 to 6 h. Under these conditions, measured humidity in the dehydrator was 5 - 30%.

• Removal of the remaining water - stabilization of the dehydrated apple pomace at a temperature which is, in general, from 20 to 25 °C lower than the temperature in the dehydrator, generally for 1 to 2 h, which enables condensation and water removal. • grinding of dehydrated apple pomace, i.e. obtaining apple pomace flour having a particle size less than 300 pm, low water activity (0.2 - 0.4) and low water content (4 - 6 wt%), which enables the stability during prolonged storage.

The apple pomace flour obtained as described shall be packed in multilayer natron jackets and sealed. The health and sanitary inspection shall be performed periodically, in order to confirm safety, i.e. to detect possible presence of pesticides, heavy metals, and mycotoxins. According to the present invention, apple pomace flour is determined by levels of minerals present, overall and specific carbohydrates levels, and presence of proteins, lipids, dietary fibers, phenolics and flavonoids, as well as by the antioxidative activity. These determinations have shown that apple pomace flour has extremely high content of potassium, dietary fibers, phenols and flavonoids, while it is low in calories, as compared with standard flours. Furthermore, the functional properties have also been assayed, such as swelling and water and oil holding capacity, etc. The results indicated high potential of use of apple pomace flour as a food ingredient and as a component of various formulations of functional food products and also indicated possible physiological effect of apple pomace flour in an organism. Moreover, the in vivo study confirmed the effect of apple pomace flour present in food on the regulation of glucose and lipids metabolism. The APF according to the present invention may be used for preparing enriched and gluten- free cookies and muffins, using pure apple pomace flour, and also using mixtures of apple pomace flour with other gluten-free flours. Enriched confectionary products, as well as gluten-free products obtained in the laboratory, are assayed in order to elucidate their nutritive and sensorial properties which are very positively evaluated. Enriched cookies contain from 2.4 to 7.2 g of dietary fibers per 20 gram portion, depending on the portion of apple pomace flour in the cookies, i.e. depending on the portion in which the wheat flour is replaced by apple pomace flour (e.g. 25, 50 and 75 wt%). Total phenolics and flavonoid content in cookies containing the highest portion of apple pomace flour is 2 to 10 times higher compared with the control (standard cookies without apple pomace flour), while antioxidative activity is even 10 times higher.

The content and health inspection of the flour

The apple pomace flour obtained by the method according to the present invention was exposed to a health and sanitary inspection in order to confirm safety i.e. to detect the possible presence of pesticides, heavy metals, and mycotoxins. The analysis confirmed that the apple pomace flour satisfies all health and food safety requirements. Moreover, the flour satisfies not only food safety requirements but also dietary products safety requirements. The composition of the flour is shown in Table 1. The total content of dietary fibers in the flour is 35 - 50 g/lOOg, carbo hydrates 48 - 55 g/lOOg, proteins 3.1 - 5.5 g/lOOg, lipids 1.3 - 4.3 g/lOOg.

The data shown in Table 1 indicate that the apple pomace flour obtained by the method according to the present invention has high dietary fibers content and preferred minerals, specifically potassium content.

In general, standard flours used for the preparation of confectionary and bakery products have very low dietary fiber content (Hager et al, 2012). Given that apple pomace flour contains 100, 20, 15 and 12.5 times higher dietary fiber content than flour obtained from rise, buckwheat, com and wheat, respectively, it may certainly be used to compensate low dietary fiber content in conventional confectionary and bakery products. This is particularly advantageous for gluten- free products.

Table 1. Composition of apple pomace flour

Composition Content

Total carbohydrates g/lOOg 48 - 55

Fibers g/lOOg 35 - 50

Lipids g/lOOg 1.3 - 4.3

Nitrogen g/lOOg 0.6 - 1.0

Proteins g/lOOg 3.1 - 5.5

Cellulose % 13 - 19

Glucose % 7.7- 16.8

Fructose % 20 - 33

Sacharose % 5.4 - 9.3

Sorbitol% 0.5 - 0.7

Potassium mg/kg 4642 - 6398

Calcium mg/kg 455 - 744

Sodium mg/kg 370 - 540

Magnesium mg/kg 394 - 715

Copper mg/kg 2.4 - 5.0

Zink mg/kg 0.6 - 8.9 Also, potassium content in APF is 5 times higher than the content in rice flour and 3 times than in corn flour. It was found that lower levels of potassium in a diet are associated with a higher risk of hypertension, type 2 diabetes, etc.

In addition to being gluten-free, APF does not contain the antinutritional factor phytic acid that slows down the absorption of minerals, i.e. reduces the bioavailability of Ca, Mg, Zn and Cu in the digestive tract, and inhibits pepsin, amylase, and trypsin, and which is present in cereals and pseudocereals. It is also important to note that APF has a 15 to 20% lower caloric value than the aforementioned flour.

Total phenolics and flavonoids content, and antioxidative properties

Flour obtained by the method according to the present invention, i.e. by using dehydration of the pomace obtained by several juice producers, is characterized by the total phenolics and flavonoid content, in parallel with the Apple egg product, which is the most similar commercially available product used for comparative purposes. Total phenol content (TPC) and total flavonoid content (TFC) in APF, i.e. in aqueous-ethanol extracts of APF and Apple egg (AE) is expressed in gallic acid equivalents (GAE) and quercetin equivalents (QE). The values for three different samples of APF are shown in Table 2 for the purpose of illustration only. As it can be seen, .TPC in the extracts of analyzed APF samples ranges from 6.1 to 8.1 mgGAE/g (Folin method), and it is 1.5 to 2 times higher than the content in Apple egg, while TFC in the APF samples ranges from 24.7 to 34.6 mgQE/g, which is 2 to 3 times higher.

Table 2. Comparison of total phenols content (TPC) and flavonoids content (TFC), as well as antioxidative activity (DPPH, ABTS, HPMC) of flour (APF 1-3) from apple pomace obtained from three different juice producers from Serbia and commercially available Apple egg (AE).

Sample TPC FC TFC ABTS DPPH HPMC

mgGAE/g mgQE/g mmolTE/lOOg mmolTE/lOOg %/ml

APF1 7.7±0.3 24.7±l.4 l0.0±0.7 3.8±0.2 60±2 APF2 6.U0.2 27.4±l.4 9.2±0.8 3.3±0.3 60±2 APF3 8.l±0.3 34.6±2.2 9.5±l.O 4.5±0.4 87±4 AE 4.2±0.2 12.2±0.7 3.l±0.4 2.9±0.4 43±2 In addition, measurements of the antioxidative activity of aqueous-ethanol extracts of APF and AE have been performed by the standard spectrophotometric methods based on trapping the artificial radical species DPPH and ABTS, as well as by the electrochemical method based on reduction of the anodic current of the hydrogen peroxide and mercury complex (HPMC). The antioxidative activity measured by the DPPH (2,2-diphenyl- 1- picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) test is expressed in Trolox equivalents (TE), while the activity measured by the HPMC method is expressed in percentages per milliliter of extract (%/ml). By using these three methods, it is unequivocally confirmed that the antioxidative activity of APF is significantly higher compared to Apple egg (Table 2). The antioxidative activity of samples of APF extracts analyzed by the DPPH and ABTS test ranges from 3.3 to 4.5, i.e. 9.2 to 10 mmolTE/lOO g, which is 1.2-1.6, i.e. about 3 times higher than AE, while the activity analyzed by the HPMC method ranges from 60 to 87%/ml, which is 1.4 to 2 times higher.

Determined phenolics and flavonoids content, as well as the antioxidative properties, confirmed the justification of the use of APF, as a dietary preparation enriched with natural antioxidants and as an additive that enriches standard products with natural AOs. As an example, phenolics content in APF is 60, 50, 8 and 1.5 times higher than in wheat, rice, corn and buckwheat flour, respectively. The antioxidative activity of APF is also several times higher compared to standard flour. It is extremely important to note that during the one-year storage, the antioxidative activity and the phenol content in APF have not been statistically significantly changed, and that it is not necessary to add anti-lumping agents to APF.

In the end, it should be noted that APF is a completely natural product, without any additives, unlike Apple egg, which contains pectin and unlike standard flour which contains various additives for lumping prevention, and other additives.

Technological and functional properties of Apple pomace flour

In addition, the technological and functional properties of flour obtained by the present invention have been determined. Water Holding Capacity (WHC) of apple pomace flour ranges from 5.4 to 6.5 g water/g while the literature values for wet or dry apple pomace ranges from 1.62 (Figuerola et al. 2005) to 6.3 g water/g (Ktenioudaki et al. 2013). The WHC of all APF samples is higher by about 2.5 times compared to the Apple egg capacity, as shown in Fig. 2. Oil Holding Capacity (OHC) amounts to 1.2 to 1.7 g oil/g and it is in accordance with the results of other authors finding that OHC amounts to a maximum 1.69 g oil/g (Cerda- Tapia et al. 2015). As shown in Fig. 2, APF samples compared to Apple egg have a somewhat higher OHC.

Water and oil holding capacity

Figure 1. Water (WHC) and oil holding capacity (OHC) capacity of apple pomace flour produced from apple pomace originating from three domestic apple juice factories (APF 1-3) and the most similar commercial product based on apple pomace with pectin added (Apple egg).

Apple pomace flour thermal properties

The thermal stability of APF and Apple egg samples was examined by differential scanning calorimetry (DSC). It was found that the glass transition temperature (T_g), at which the amorphous food in the "glassy" state transits to a viscous or rubbery state, in all APF samples is significantly higher (from 27 - 38 °C), than T_g shown for Apple egg and also higher than the storage temperature, which ensures stability during storage. Figure 3 shows the thermogram obtained by the DSC method for APF1 and Apple egg. While T_g for APF1 is 38 °C, which is 16 °C above the standard storage temperature (22 °C), T_g for the commercial Apple egg sample is only 21 °C. Due to the low water activity and the high T_g, flour obtained by the present invention remains unchanged during one-year storage. It is not hygroscopic, it does not cake and does not change its composition at the standard storage temperature, while the apple flavor and scent are retained.

Temperature (°C)

Figure 2. DSC of APF 1 and Apple egg obtained at heating rate 5 °C/min in nitrogen flow of

60 mL/min.

Thermal stability is monitored also at elevated temperatures, which is important for the APF behavior during the baking process in the confectionery and bakery industry. The initial thermal degradation temperature (above 200 °C) indicates that the APF can be used at the common processing temperatures.

Confectionery industry applicability

Under laboratory conditions, APF is used for producing gluten-free cookies and muffins, as the single flour and in combination with carob and buckwheat flour. Under industrial conditions up to 75 % of wheat flour was replaced by APF, i.e. functional products, with multiple elevated content of dietary fibers (DF) and antioxidants (AOs) with regard to the control containing only wheat flour, were obtained. All products obtained were assessed positively in terms of sensory quality (quality and acceptance assessment by the consumers). Cookies in which 25, 50 and 75% wheat flour is replaced with APF contain 2.4, 4.8 and 7.2 g of DF per portion of 20 grams, while the DF content in the control sample is negligible. As seen in Fig. 4, the total phenolics content in enriched cookies is higher, while there are up to 10 times more flavonoids. Antioxidative activity (ABTS and DPPH) is, and for an entire order of magnitude, increased in cookies with the highest content of APF, as can be seen in Fig. 5. During the one-year storage, these values did not change significantly.

Cookie sampl' Cookie samples

Figure 3. Increase of TPC (A) and TFC (B) of cookies in relation to percentage of wheat substitution with coarse and fine APF

Cookie samples Cookie samples

Figure 4. Increase of AO activity of cookies determined by the ABTS (A) and DPPH (B) test in relation to percentage of wheat flour substitution with coarse and fine APF

In vivo confirmation of the effect of Apple pomace flour presence in a diet on the regulation of glucose and lipid metabolism

In this study, the two different doses of APF and antilipemic simvastatin were added to food with a high content of lipids in order to comparatively monitor the effect on the lipid and glycemic status of C57BL / 6J mice (Vivarium Galenika a.d., Belgrade, Serbia). The 40 mice in total were divided into five groups according to the diet (Gl-5) (Table 3). The mice were fed for 120 days with: high-fat food (G4), high-fat food with APF (10 and 20 mg daily) (G1 and G2), high-fat food with simvastatin (G3) and standard food (control group) (G5).

The dose of the drug was determined according to the daily dose for human use and the APF dose taking into account the DF content determined by the chemical analysis of APF and the recommended daily intake of DF.

Table 3. Lipid and glycemic status of the C57BL/6J mice over 120 days fed with high-fat food without (G4) and with the addition of 10 and 20 mg of APF per day (Gl and G2) and simvastatin (G3) compared to the control group fed with standard food (G5).

Gl G2 G3 G4 G5

Total cholesterol

3.50 ± 0.38 ^a 3.73 ± 0.3 l ^a 3.60 ± 0.44 ^a 3.73 ± 0.75 ^a 2.55 ± 0.27 ¹ (mmol/L)

Triacylglycerol

1.10 ± 0.12 ^b 1.45 ± 0.51 ^ab 1.24 ± 0.25 ^b 2.01 ± 0.39 ^a 1.36 ± 0.39 ^! (mmol/L)

Glucose (mmol/L) 10.38 ± 0.79 ^b 10.74 ± 1.37 ^b 12.09 ± 0.66 ^ab 14.24 ± 2.59 ^a 10.31 ± 1.43

Body weight increase (g) 2.99 ± 1.37 ^cd 5.40 ± 1.24 ^b 5.05 ± 0.82 ^bc 1.59 ± 1.08 ^d 7.93 ± 2.03 ^a

Initial weight (g) 21.96 ± 0.11 ^a 19.53 ± 1.28 ^b 21.33 ± 0.85 ^a 21.40 ± 0.63 ^a 18.56 ± 0.91 ^b

Terminal weight (g) 24.95 ± 1.39 ^ab 24.93 ± 1.53 ^ab 26.38 ± 0.70 ^a 22.99 ± 1.24 ^b 26.49 ± 2.1 l ^a

Food consumption

2.01 ± 0.06 ^bc 2.25 ± 0.14 ^b 1.82 ± 0.07 ° 1.78 ± 0.09 ^c 3.22 ± 0.47‘

(g/day)

Water consumption

5.98 ± 0.39 ^bc 7.19 ± 0.36 ^a 5.74 ± 0.23 ^c 7.39 ± 0.27 ^a 6.30 ± 0.61 (mL/day)

* According to Tukey, HSD test (p <0,01) values are presented as the mean value ± SD, different superscript letters within the same row indicate significant differences.

The study has unequivocally shown that the addition of APF to high-fat food has a significant effect on the reduction of glucose and triacylglycerol levels (different superscript letters within the same row indicate significant differences). Groups Gl and G2 taking two apple pomace flour doses had a significant reduction in glucose and triacylglycerol levels compared to the G4 group. The results of the comparison of the effects of different APF doses on metabolism enabled the optimization of daily intake of APF as a dietary preparation. It was found that the optimal APF dose, which has a significant positive effect on the regulation of glucose and triacylglycerol levels, is 10-30 g/day.

Claims

Patent claims

1. A method for producing apple pomace flour characterized by the following

steps:

• aseptic takeover of fresh apple pomace obtained by pressing whole apples;

• placement of the fresh apple pomace on perforated plates;

• placement of the perforated plates in a dehydrator;

• dehydration of the fresh apple pomace at temperature below 55 °C, preferably at temperature in the range of 45 and 55 °C, for up to 6 h;

• stabilization of dehydrated apple pomace by removal of residual humidity at temperature which must be lower than temperature in the dehydrator;

• grinding of the apple pomace obtained in the previous step to obtain flour having particles size below 300 pm.

2. Apple pomace flour (APF) obtained by the method according to claim 1 characterized in that it comprises:

Dietary fibers in the range of 35 - 50 g per lOOg APF,

Carbohydrates in the range of 48 - 55 g per lOOg APF,

Proteins in the range of 3.1 - 5.5 g per lOOg APF,

Fats in the range of 1.3 - 4.3 g per lOOg APF.

3. The apple pomace flour (APF) according to claim 2, characterized in that it further comprises potassium in the range of 4642 - 6398 mg per kg APF.

4. The apple pomace flour (APF) according to claims 2 or 3 characterized in that it is gluten free.

5. The apple pomace flour (APF) according to claims 2 to 4, characterized in that the content of the polyphenols is in the range of 4 - 10 mg per g APF.

6. A product comprising 5 - 95 wt % of the APF according to claims 2 to 5, characterized in that the product is selected from the group of food products, such as bread, biscuits, and muffins.

7. The product according to claim 6 for use to feed people with glucose and/or lipid

level disorder.

8. Use of the apple pomace flour (APF) according to claims 2 to 5 in food industry.

9. The use of the apple pomace flour (APF) according to claim 8 for the production of food products, preferably confectionary and bakery products.

10. The use of the apple pomace flour (APF) according to claim 8 or 9 for production of gluten-free food products and/or their fortification.

11. The use of the apple pomace flour (APF) according to claims 2 to 5, as a dietary preparation.

12. The use of the apple pomace flour (APF) according to claim 11 characterized in that the optimal daily dose of the APF is in the range of 10 to 30 g.