Gluten-free bakery products

Abstract

The invention relates to gluten-free bakery products and production methods using emulsifying salts and caseins.

Description

[0001] GLUTEN-FREE BAKERY PRODUCTS

[0002] Technical Field

[0003] The invention relates to gluten-free bakery products and production methods using emulsifying salts and rennet caseins.

[0004] State of the Art

[0005] Celiac disease is one of the most common lifetime diseases worldwide, with an estimated average incidence of 1% in the general population. In addition to celiac disease, people with non-celiac gluten sensitivity, gluten ataxia and dermatitis herpetiformis should choose a gluten- free diet. People with these conditions, particularly celiac disease, are unable to consume some of the most common products on the market, including breads and other food products made with wheat flour. Manufacturing high quality gluten-free bakery products is challenging as gluten is the primary contributor to desired bread texture. Sales of gluten-free products grew by 10.4% annually between 2015 and 2020.

[0006] Recently, rice flour has been widely recommended as an alternative for gluten-free bread making due to its hypoallergenic proteins, mild taste and white color, but rice-based bread has a low volume and a hard crumb. The use of other grain sources in bread making can increase the variety of products and also improve their nutritional properties, but gluten-free bakery products are only acceptable by consumers when their sensory characteristics are similar to those of regular wheatbread. Gluten-free breads and bakery products are often characterized by poor quality and have a dry, low volume and crumbly texture.

[0007] Ingredients such as modified starch, hydrocolloids, emulsifiers, enzymes and proteins from different sources have been proposed to improve the quality of gluten-free breads. A common practice in food processing is the incorporation of protein components into the product formulation to enhance product attributes such as flavor, texture, nutritional value, color and storage stability. Protein sources commonly used in the production of gluten-free bakery products are legume proteins, eggs, dairy proteins and gluten-free cereal proteins. These ingredients can be used in bread for both nutritional and functional benefits. However, proteins often do not meet food processing requirements and additional modifications are required. The use of enzymes as processing aids in bread making is a common method of improving functional properties to promote networks and enhance dough baking properties. One enzyme that has received intense interest due to its ability to cross-link proteins is transglutaminase. This enzyme catalyzes the acyltransfer reaction between the y-carboxyamide group of peptide- bound glutamine residues (acyl donors) and various primary amines (acyl acceptors), including the s-amino group of lysine residues in certain proteins. Compared to other cereals, rice has a high lysine content, thus potentially having more substrates for enzyme action.

[0008] Different starch sources, various thickeners and various protein sources are used to eliminate textural defects that occur in the production of gluten-free bakery products. However, although studies have shown that the quality of gluten-free bakery products can be improved to a certain extent, despite all the available literature, there are major textural, sensory and visual differences between gluten-free products and regular products.

[0009] One of the most important problems encountered in gluten-free bakery products is the ability of the dough to hold gas, in other words, its rising is most affected. As a result, the texture of bakery products becomes dense, hard and brittle. In addition, the color of gluten-free bakery products is close to white and the aroma profile is much weaker (starchy) than normal.

[0010] Rennet casein and caseinates (acid casein, sodium caseinate) are protein sources whose use in gluten-free bakery products has been investigated in the past. Acid casein from caseinates are proteins obtained by the principle of precipitation of caseins at the isoelectric point. In this process, the pH value of the environment is reduced to 4.6 and caseins are coagulated. During the process, changes in physical (e.g. solubility) and chemical (e.g. mineral composition) properties occur due to the dissolution of colloidal calcium phosphate in the structure of caseins. Sodium caseinate is obtained by neutralizing acid casein with sodium hydroxide, which exhibits better solubility than acid casein.

[0011] Rennet casein is obtained by proteolytic destabilization of casein micelles. Rennet casein is insoluble in water; it can only be dissolved at extreme pH values or using calcium-retaining salts such as phosphates, polyphosphates and citrates. Since milk is precipitated at pH values close to neutral in the production of rennet casein, it has a high mineral content (calcium phosphate content).

[0012] Rennet casein is widely used in both food and non-food applications. Rennet casein is mostly used in the production of process cheese and cheese analogues, as it can significantly contribute to the structure and functional support of these products. In these processes, rennet casein is partially solubilized through the use of emulsifying salts (calcium sequestrants) and its properties are adjusted to the specific application. In processed cheese production, emulsifying or melting salts are used to give the product the desired physical structure and stabilization. These salts are not emulsifiers but increase the solubility of caseins by dissolving protein-bound calcium, thus releasing casein proteins and revealing their emulsifying properties. Although the working principle of emulsifying salts is similar (chelating protein-bound calcium), the ion exchange and creaming (forming new interactions) capabilities of different emulsifying salts affect the behavior of caseins in different ways, resulting in major differences in the structure of the final product. For example, in processed cheeses, the texture of the processed cheeses can vary from a soft spreadable texture to a hard texture that does not melt with heating, depending on the properties of the salt used with rennet casein. In this context, rennet casein and various emulsifying citrate and phosphate salts were examined and which combination of emulsifying salt and rennet casein would have gluten-like gas retention ability was investigated.

[0013] Figures

[0014] Figure 1: Flow chart of gluten-free bread production using rennet casein and emulsifying salts

[0015] Detailed Description of the Invention

[0016] The use of emulsifying salts in combination with rennet casein creates a gluten-like protein structure in gluten-free bakery products, which improves product texture. At the same time, the use of casein and emulsifying salts in gluten-free formulations improves the sensory and visual (color) structure of bakery products and increases the nutritional value compared to gluten-free products.

[0017] In general, emulsifying salts (ES) consist of a monovalent cation (sodium-Na, potassium-K) and a multivalent anion (phosphate, citrate). Emulsifying salts (ES) are not amphiphilic and therefore are not emulsifiers in their own right.

[0018] Emulsifying salts (ES) have an important role in the production of process cheeses. The main role of ES in process cheese production is to support the emulsifying ability of cheese proteins. The mechanism of action of ES in any cheese system includes the following:

[0019] 1. Removal of calcium from the protein system;

[0020] 2. Peptitizing, solubilizing and dispersing proteins;

[0021] 3. Hydration and swelling proteins; 4. Emulsifying the oil and stabilizing the emulsion;

[0022] 5. Controlling and stabilizing pH;

[0023] 6. Creating a suitable structure of the product after cooling.

[0024] Other possible effects of emulsifying salts (ES) on process cheese include flavor and color. Some emulsifying salts show bacteriological effects. Monophosphates have a specific bacteriostatic effect, which is even more pronounced with higher phosphates and polyphosphates. Citrates do not have such effects and may even be subject to bacterial degradation.

[0025] Emulsifying salts (ES) are normally added at a rate of 3 g per 100 grams. The use of a very high total ES concentration (close to 3 g per 100 grams) results in the dissolution of all the original protein-bound calcium in the raw material cheese. The ability of emulsifying salts (ES) to complex calcium on a similar molar basis increases in the order orthophosphate < citrate < pyrophosphate < hexametaphosphate.

[0026] Citrates

[0027] Citrates are salts of citric acid. In the nomenclature of the International Union of Pure and Applied Chemistry (IUPAC), citric acid is 2-hydroxypropane-l,2,3-tricarboxylic acid. Depending on the decomposition steps, citric acid forms citrates, hydrogen citrates and dihydrogen citrates. Citrate-based salts are obtained by replacing acidic hydrogen atoms with cations from tribasic citric acid. Citrate salts are soluble in water and have pH values of approximately 3.8 to 8.2 for a 1 g / 100 mL solution, with an increase in pH values as more H+ is replaced by Na+. Neutralization of H+ ions of citric acid with Na+ ions results in three types of salts: mono-, di- and trisodium citrate. Monosodium and disodium citrates result in an acidic product and poor texture, including oiling-off, so they are not used alone but can be used in mixtures to correct the pH of process cheese. Sodium citrate was the first emulsifying salt used to make process cheese. Other forms of citrate, such as potassium or ammonium citrates, have been evaluated for use in low-sodium process cheese production.

[0028] Phosphates are salts of phosphoric acid. A distinction is made between monomeric (single phosphate) and polymeric (multiple) phosphates (Lucey et al., 2011).

[0029] Orthophosphates

[0030] Monophosphates are better known under the name orthophosphates (Lucey et al., 2011). Orthophosphates are the starting material for the production of all condensed phosphates (McCullough et al., 1956). Orthophosphates and condensed phosphates contain one strong acid or ionized group (hydrogen atom) per phosphorus atom. Orthophosphates also contain a weak acid function. All phosphates, from orthophosphates to polyphosphates, behave as highly charged anions (Lucey et al., 2011).

[0031] The Ca2+binding ability of orthophosphates is limited below pH 6 and calcium phosphates are formed around pH 6. Orthophosphates and pyrophosphates have high buffering capacities in the pH ranges 2-3, 4.5-9.0 and 10-12. Orthophosphates are excellent buffers and are mostly used to stabilize the pH of processed cheese. The strong buffering capacity of orthophosphates decreases with increasing chain length of polyphosphates (Lucey et al., 2011).

[0032] Monosodium and trisodium phosphates are mainly used to correct pH in process cheese production. These salts are (a) monosodium dihydrogen phosphate (MSF), (b) disodium hydrogen phosphate (DSP) and (b) trisodium phosphate (TSF) (Lucey et al., 2011).

[0033] Di sodium phosphate (DSP)

[0034] It is an inorganic compound with the formula Na2HPO4. Hydrated forms of salts 2, 7, 8, 12 as well as anhydrous forms are known. All of these are soluble in water and are white powders. Anhydrous salt is hygroscopic. DSP can be produced by neutralizing phosphoric acid with sodium hydroxide. DSP is one of the main types of ES used in the process cheese industry, either alone or in combination with other salts. The advantages of process cheese made with DSP include easy melting in cooking, good flavor and stretching. DSP also has some bacteriostatic effects. The disadvantage of DSP is the strong potential for crystal formation due to the low solubility of this type of emulsifying salt.

[0035] Polymeric (multiple) phosphates

[0036] Polymeric phosphates are obtained from acid orthophosphates by heat treatment and separation from condensate water, hence they are called condensed phosphates. Polymeric phosphates can be divided into three groups: linear chain-forming polyphosphates, ring-forming metaphosphates and cross-linked ultra-phosphates.

[0037] Linear chain-forming components can be distinguished in two groups: short-chain and long- chain polyphosphates. Cross-linked or ring-forming phosphates are not used in process cheese production. Polyphosphates consist of a mixture of phosphates of different chain lengths formed during the production of this ES. In most cases, glassy and non-crystalline compounds are obtained for long-chain polyphosphates. The most important ES for process cheese production are short-chain polyphosphates (diphosphates and triphosphates) and long-chain polyphosphates (Graham salts), often (erroneously) referred to as hexametaphosphates. True hexametaphosphates form rings and are not used in process cheese making.

[0038] Condensed phosphates (short chain)

[0039] Condensed short-chain (n = 2 or 3) phosphates used in process cheese production are soluble in water. There are three short-chain condensed phosphates of technological importance: sodium acid pyrophosphate (SAPP), tetrasodium pyrophosphate (TSPP) and sodium tripolyphosphate (STPP). Among the tripolyphosphates (n = 3), STPP is used in small amounts because its high levels can cause astringency in food products.

[0040] TSPP (Tetrasodyum pyrophosphate)

[0041] As a salt, it is a white, water-soluble solid. It is composed of the pyrophosphate anion and sodium ions. Tetrasodium pyrophosphate is produced by reacting phosphoric acid with sodium carbonate to form disodium phosphate, which is then heated to 450 °C to form tetrasodium pyrophosphate. TSPP has the lowest water solubility at 20 °C of any of the common emulsifying salts used in process cheese production. TSPP is a neutral salt and readily complexes or precipitates alkaline earth metals, including Ca2+. It is well known that TSPP is very effective at dispersing caseins in dairy systems and under certain conditions can cause gelation even at pH > 6. TSPP can recrystallize after processing. TSPP is known to promote cream formation and care should be taken in its use in process cheese to avoid excessive cream formation.

[0042] SAPP (Sodium acid pyrophosphate)

[0043] It is a white, water-soluble solid that acts as a buffering and chelating agent in many food processing applications. It forms a hexahydrate when crystallized from water, but dries above room temperature.

[0044] SHMP (Sodium hexametaphosphate)

[0045] Sodium hexametaphosphate is an emulsifying salt belonging to the group of long-chain polyphosphates. Long-chain polyphosphates act as ion exchangers; they are also very effective in causing protein solubilization and the soluble protein content in processed cheese increases with increasing polyphosphate addition. Technologically glassy phosphates show an average degree of condensation of 4 to 25. The degree of condensation describes the number of phosphorus atoms (P) present per molecule on average. Graham salt (sodium hexametaphosphate; SHMP) has an average degree of condensation of 10 to 25. Sodium hexametaphosphate (SHMP) is a salt of the compound Na6[(PO3)e].

[0046] Other phosphate-based emulsifying salts

[0047] Although potassium salts of phosphoric acids are more soluble than the corresponding sodium salts, they are not commonly used in process cheese making because at high levels they impart a bitter taste to the product. Sodium aluminium phosphates (SA1P) (Nai5A12s(PO4)s-H2O) are sometimes used in process cheese production, but more commonly in the manufacture of imitation / analogue cheeses. SA1P can be used in process cheese at a maximum level of 3 g / 100 g and does not show crystal growth. Other forms of phosphates such as ammonium phosphates, glycerol-phosphates and sodium magnesium phosphate have also been tested in process cheese making.

[0048] Other types of emulsifying salts

[0049] Tartrates, tartaric acid salts, lactates and lactic acid salts have been tested as emulsifying salts. Since it is not possible to obtain acceptable process cheese quality from tartrates due to the formation of crystals in the product during storage, these types of emulsifying salts are no longer used.

[0050] Sodium potassium tartrate (Rochelle salt) has also been tried as an emulsifying salt in process cheese production, but was abandoned because of its tendency to develop texture defects and grittiness. Sodium salts of trihydroxy glutaric acids have been used alone or in combination with other ESs and have been reported to produce process cheese with good consistency. Diglycolic acid and its salts have also been suggested as possible ESs.

[0051] Emulsifying salts preferably used in the invention are Tetrasodium Pyrophosphate (TSPP), Disodium Phosphate (DSP), Sodium Acid Pyrophosphate (SAPP) and Sodium Hexametaphosphate (SHMP). The proportion of emulsifying salts was between 0.3% and 2% by weight in the dough mixture before baking.

[0052] Bread production

[0053] For gluten-free bread production, it was first aimed to determine the lower and upper limits of emulsifying salt and rennet casein ratios to be used in gluten-free bread formulation. In order to determine these levels, 20 preliminary trials with varying ratios of TSPP and rennet casein were produced. Based on the results obtained in the preliminary trials, the lower and upper limits of the amount of emulsifying salts and rennet casein with different properties were decided. Gluten-free bread, which is the subject of the research, consists of a mixture of rice flour, rennet casein and any of the emulsifying salts. In this study, each emulsifying salt (Tetrasodium Pyrophosphate (TSPP), Disodium Phosphate (DSP), Sodium Acid Pyrophosphate (SAPP) and Sodium Hexametaphosphate (SHMP)) and rennet casein were used in different ratios to produce bread 10 times each. Rennet casein was used in the pre-baking dough mixture in the range of 15%-25% by weight, preferably 20%.

[0054] Bread made from wheat flour only (C) was used as control. For comparison, breads made from rice flour only (P), breads containing a mixture of rice flour and rennet casein (P-KZ), samples containing rice flour and 1% DSP (P-DSP), samples containing rice flour and 1% TSPP (P- TSPP), samples containing rice flour and 1% SAPP (P-SAPP) and samples containing rice flour and 1% SHMP (P- SHMP) were produced. The standard method (Method 10-20) recommended by AACC (American Association of Cereal Chemists) was used for wheat flour bread production.

[0055] Bread ingredients were weighed in the ratios indicated in Table 1 and Table 2 and kneaded in a household dough kneader (Kitchen Aid, USA) at the second stage for 5 minutes. The kneaded dough was weighed 230 g each, placed in a greased baking dish and shaped. At the same time, 30 g of dough was placed in plastic containers for texture analysis. The doughs were placed in a fermentation cabinet set at 40°C with 70% relative humidity and fermented for 1 hour. After the fermentation process was finished, the doughs were placed in a baking dish and baked in an oven preheated to 200°C for 33 minutes. For texture analysis, 30 grams of dough was placed in each container and analyzed after the fermentation process. After baking, the breads were wrapped with a cloth and left on the grill at room temperature for 2 hours to cool down. After 2 hours, the breads were analyzed on day 0. Then the breads were placed in polyethylene bags and kept at room temperature for 1 day and analyzed.

[0056] The ratios of the components in Table 1 and Table 2 are original; for convenience in the other sections, the ratios are given for similar proportions.

[0057] Table 1. Formulations used in preliminary trials.

[0058] Emulsifying Rennet Rice Drinking , .

[0059] E „xamp .les o Sa .lt ( zg \) Casein Flour M ,ay • a Sugar Sal ,t Water Vi .neg ®ar Baking ® .

[0060] TSPP (g) fe) ® ® (ml)(n,l) P»w<ler®

[0061] Pre-Test 1 100 1.43 5.35 1.5 90

[0062] Pre-Test 2 25 75 1.43 5.35 1.5 90

[0063] Pre-Test 3 2.5 25 75 1.43 5.35 1.5 90

[0064] Pre-Test 4 1 10 90 1.43 5.35 1.5 90 Pre-Test 5 2.5 10 90 1.43 5.35 1.5 90

[0065] Pre-Test 6 2.5 100 1.43 5.35 1.5 90

[0066] Pre-Test 7 2.5 5 95 2.86 5.36 1.5 90

[0067] Pre-Test 8 1 25 90 2.86 5.36 1.5 90

[0068] Pre-Test 9 1 25 75 2.86 5.36 1.5 90

[0069] Pre-Test 10 2.5 15 85 2.86 5.36 1.5 90

[0070] Pre-Test 11 2.5 10 90 2.86 5.36 1.5 90

[0071] Pre-Test 12 1 25 75 2.86 5.36 1.5 55 35

[0072] Pre-Test 13 25 75 2.86 5.36 1.5 90 10 5

[0073] Pre-Test 14 1 25 75 2.86 5.36 1.5 80 10

[0074] Pre-Test 15 1 10 90 2.86 5.36 1.5 80 10

[0075] Pre-Test 16 1 5 95 2.86 5.36 1.5 80 10

[0076] Pre-Test 17 0.1 25 75 2.86 5.36 1.5 90

[0077] Pre-Test 18 0.25 25 75 2.86 5.36 1.5 90

[0078] Pre-Test 19 0.1 20 80 2.86 5.36 1.5 90

[0079] Pre-Test 20 0.25 20 80 2.86 5.36 1.5 90

[0080] Table 2. Gluten-free bread formulation.

[0081] „ , Emulsifying Salt Rennet Instant „ „ Drinking

[0082] Example Rice Flour . . Sugar Salt .. , no. ‘ (gram) . (gram) (TSPP, DSP, Casein Yeast , ( ,gram) , ( ,gram . Water

[0083] 7) .T. SAPP, SHMP) (gram) (gram) (mL)

[0084] 1 85 1 15 2.86 5.35 1.5 90

[0085] 2 90 1.7 10 2.86 5.35 1.5 90

[0086] 3 85 0.01 15 2.86 5.35 1.5 90

[0087] 4 85 1 15 2.86 5.35 1.5 90

[0088] 5 90 0.3 10 2.86 5.35 1.5 90

[0089] 6 85 1.98 15 2.86 5.35 1.5 90

[0090] 7 80 1.7 20 2.86 5.35 1.5 90

[0091] 8 92.07 1 7.92 2.86 5.35 1.5 90

[0092] 9 80 0.3 20 2.86 5.35 1.5 90

[0093] 10 77.92 1 22.07 2.86 5.35 1.5 90

[0094] Table 3. Formulation of breads containing only rice flour1, rice flour and rennet casein2, rice flour and TSPP3, rice flour and DSP4, rice flour and SAPP5and rice flour and

[0095] SHMP6.

[0096] „ , Emulsifying Salt Rennet Instant „ „ .

[0097] Example Rice Flour , . / A r.™ ,7Sugar Salt Drinking

[0098] NTo. ( zgram x) (gram) (TS L P ,,P,,, D,,.SP, C , asein , , Yeast , ( ,gram .) ( ,gram .) Wat ® .

[0099] ’ SAPP, SHMP) (gram) (gram) ’ er (mL) ’

[0100] P1100 - - 2.86 5.35 1.5 90

[0101] P-KZ285 - 15 2.86 5.35 1.5 90

[0102] P-TSPP3100 1 - 2.86 5.35 1.5 90

[0103] P-DSP4100 1 - 2.86 5.35 1.5 90

[0104] P-SAPP5100 1 - 2.86 5.35 1.5 90

[0105] P-SHMP6100 1 - 2.86 5.35 1.5 90

[0106] Bread components produced from wheat flour (C) are shown in Table 4 and the production flow chart is as shown in Figure 1. Table 4. Formulation of bread made from wheat flour.

[0107] Components Amount

[0108] Flour 100 g

[0109] Sugar 6 g

[0110] Maya 5.3 g

[0111] Oil 3 g

[0112] Salt 1.5 g

[0113] Water 60 ml

[0114] Whey Powder 1 g

[0115] Ascorbic Asit 50 ppm

[0116] Dough Analysis pH

[0117] The pH value of the dough was measured using a pH meter. The calibrated pH meter probe was directly immersed in the prepared dough and the reading was taken after the value stabilized.

[0118] Dough texture

[0119] Texture analysis of the dough was carried out using a texturing device with uniaxial compression and the hardness and stickiness values of the dough were measured. 30 grams of dough samples were transferred into 40 mm diameter plastic containers. The texture properties of the dough were measured with a 25.4 mm cylindrical probe at a penetration depth of 5 mm and a speed of 1 mm / s.

[0120] Bread Analysis

[0121] Volume and weight measurement

[0122] After baking, the bread samples were placed on the grill and allowed to cool at room temperature for 2 hours. Afterwards, volume and weight measurements were made. The weight loss of the bread samples was calculated by the following formula.

[0123] % Weight loss = (dough weight - bread weight) x 1001 dough weight

[0124] The volume of the bread was measured using a volume meter (Simsek Laborteknik, Ankara) which works on the principle of rapeseed displacement (AACC Method 10-05.01). Rapeseed seeds were placed in one chamber of the volume meter and whole bread was placed in the other empty chamber. The volumeters were placed on a stable surface and inverted so that the chamber filled with rapeseed remained upside down. The reading was taken from the measuring cylinder of the volume meter after the value was stabilized.

[0125] Moisture and total dry matter analysis

[0126] The aluminium weighing cups were tared (mi) with the help of a clamp on an analytical balance (±0.001 g precision) and 3 g each of the homogenized bread samples were transferred to the aluminium weighing cups. The bread samples were kept in an oven at 105 °C until they reached constant weight (m2). After reaching constant weight, the bread samples were removed from the oven and allowed to cool in a desiccator for 15 minutes. The cooled bread samples were weighed again and the final weights were recorded (m3). Moisture and total dry matter values of homogenized bread samples were calculated by the following formula: m2-m3

[0127] R= 100 m2-ml

[0128] R = Moisture content (%) mi = Tare of the container (g) m2 = First weighing (g) m3 = Final weighing (g)

[0129] Total Dry Matter Amount was calculated with the formula below.

[0130] TDM = 100 - R

[0131] Where : TDM = Total dry matter (%)

[0132] Protein analysis

[0133] Kjeldahl method was used to determine the total nitrogen content of the homogenized bread samples. The total nitrogen content was multiplied by the translation factor 6.25 and % protein content was determined indirectly. The equation is as follows.

[0134] % Nitrogen Amount 100 %Protein Amount= %Nitrogen x 6.25

[0135] Vi= Amount of 0.1 N HC1 spent in titration for the main experiment (mL)

[0136] Vi= Amount of 0.1 N HC1 spent in titration for the witness experiment (mL)

[0137] = Normality of the HC1 solution used in the titration: S= Sample quantity (g)

[0138] Oil analysis

[0139] The homogenized bread samples were analyzed for fat using a Soxhlet apparatus (WisTherm PMI Laborteknik, Germany) which works on the principle of continuous extraction of a fat solvent. After all the collected solvent in the extract was evaporated, the remaining sample was measured. The equation is as follows (Avci et al., 2021):

[0140] % Total Fat Amount 100

[0141] S= Sample quantity (g)

[0142] F= The tare of coarse filter paper (g)

[0143] K= Cartridge tare (g)

[0144] E= Total weight of coarse filter paper, cartridge and degreased sample after extraction (g) Salt analysis

[0145] Mohr method was used to determine the % salt content of the homogenized bread samples.

[0146] The principle of the method is that the chloride in the sample is precipitated with silver. Chromate added as an indicator reacts with the excess silver in the medium and quantification was made based on the stoichiometry of the reaction. The equation is as follows.

[0147] % Salt (Chloride) 100 NAgN03 = Normality of silver nitrate solution f = Factor of silver nitrate solution

[0148] V = Volume of silver nitrate solution used in the experiment (mL)

[0149] 0.0585 g / meq-g= Milli equivalent grams of sodium chloride m = Sample quantity (g)

[0150] DF = Dilution Factor

[0151] Color analysis

[0152] A color measuring device (PCE-CSM 7; PCE Instruments, UK) was used for the external and internal color of the bread samples. L*, +a* and +b* color values were measured at 3 different points and average values were calculated.

[0153] Texture analysis

[0154] Bread samples were prepared for Texture Profile Analysis (TP A) by cutting 2 cm3on the day following production. The samples at room temperature were double pressed with a 50 mm probe at a speed of 1 mm / s and 25% tension. Hardness, stickiness, adhesion, elasticity and chewability parameters were evaluated.

[0155] Statistical Analysis and Experimental Design

[0156] Central composite design (Mullen and Ennis, 1979) and surface response methodology (RSM) (Montgomery, 2001) were used to investigate the effects of emulsified salt and rennet casein. A 2-level factorial experimental design was used to examine the effects of the independent variables (emulsifying salt and rennet casein) with 2 star points (a = 1.414) and 2 replicates of the center point.

[0157] Multiple (stepwise) regression and RSM were used to analyze the results (Statgraphics version 5.1 plus, Manugistics, Rockville, MD).

[0158] The Tukey-Kramer test was used to compare means and differences between means were considered significant at p < 0.05. Pearson correlation coefficients were estimated between various responses (hardness, adhesiveness, bread volume, color, etc.). Caseins are special proteins that carry calcium from mother to offspring and have protein-bound calcium in their structure. In addition, caseins (a-, P-, and K-casein) are proteins that have hydrophobic and hydrophilic condensed regions, do not have a definite structure due to their high proline content, and are found as micelles in milk. These structural properties give cheeses functional properties such as melting and streching. These properties make caseins different from other proteins of plant and animal origin. In fact, caseins are completely different from whey proteins, another major protein found in milk, in terms of their functional properties. For example, cheeses obtained from whey proteins does not have the hardness, cohesiveness, melting, streching characteristics of Mozzarella cheese.

[0159] As mentioned before, emulsifying salts are actually chelating agents that dissolve the calcium bound to caseins and release the caseins. Depending on the nature of the emulsifying salt used, the dissolved calcium contributes to the formation of new interactions (emulsifying salts with creaming properties). Unlike caseinates (acid casein and sodium caseinate), rennet casein is obtained by proteolytic coagulation of casein. Thus, protein-bound calcium, whose interaction with emulsifying salts is critical, is already in its structure. In acid casein and sodium caseinate, protein-bound calcium is removed in the acid coagulation process. In short, rennet casein was preferred to take advantage of the interactions of calcium and minerals in the structure of rennet casein with emulsifying salts.

[0160] Emulsifying salts are widely used in the dairy industry, especially in the process cheese industry. In this study, the most widely used emulsifying salts with the best known properties in the dairy literature were preferred for better interpretation of the results.

Claims

CLAIMS1. A gluten-free bakery product characterized in that it comprises rennet casein and an emulsifying salt that dissolves the calcium bound to the casein protein.

2. A bakery product according to claim 1 , characterized in that the rennet casein is between15% and 25% by weight in the dough before baking.

3. A bakery product according to claim 2, characterized in that the rennet casein is 20% by weight in the dough before baking.

4. A bakery product according to claim 1, characterized in that the emulsifying salt is between 0.3% and 2% by weight in the dough before baking.

5. A bakery product according to claim 1, characterized in that the emulsifying salt is a phosphate salt or a citrate salt with sodium or potassium as the cation.

6. The bakery product according to claim 5, characterized in that the emulsifying salt is selected from the group consisting of disodium phosphate, sodium acid pyrophosphate, tetrasodium pyrophosphate, sodium hexametaphosphate or mixtures thereof.

7. A bakery product according to claim 6, characterized in that the emulsifying salt is sodium hexametaphosphate.

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