- EFFECT OF TRANSGLUTAMINASE ON FRESH CHEESE QUALITY PROPERTIES USING CITRIC ACID AS A COAGULANT. - The purpose of this study was to evaluate the effect of microbial transglutaminase (MTGase) on cheese quality properties using citric acid as a coagulant agent. - The experimental results showed that citric acid has a temperature-dependent ability to agglomerate milk proteins. - The process of protein coagulation at 50 ° C by citric acid (2.0%) gave fresh cheese with yield production. - H), dry matter content. - Analytical results of the sensory score, acidity, whey separation and color difference of fresh cheese samples during storage (28 days) showed that using MTGase better maintained the quality of the product.. - Furthermore, MTGase also improved water holding capacity (reduced whey separation) during storage and did not affect the color of fresh cheese products. - Moreover, the physicochemical and microbiological parameters of the product were also determined. - The results showed that the quality of fresh cheese coagulated by citric acid met CODEX STAN 221-2001 for unripened cheese including fresh cheese.. - fresh cheese. - citric acid.. - Paneer is a type of fresh cheese obtained by coagulating milk with heat and acids, wrapping almost all fat, casein, and whey protein. - The preparation of paneer using different milks and different techniques leads to large differences in the physicochemical, microbiological and sensory qualities of products [5].. - Citric acid, a tricarboxylic acid (C 6 H 8 O 7 .H 2 O) is a common metabolite of plants and animals and is found in the juices Doi: https://doi.org/10.54644/jte . - In addition, citric acid can be produced from fermentation of carbohydrates containing media using the bacteria Candida spp. - Citric acid is a versatile and non-toxic additive. - In recent years, this enzyme was also used to gelatinize various food proteins through the formation of cross-links resulting in the improvement of functional properties of food. - Most of the cheese in the Vietnamese market today is imported products from other nations.. - Besides, there are not many studies focusing on the effect of MTGase addition on physicochemical and sensory properties of fresh cheese made from milk powder. - Based on practical needs and current trends in domestic production, in this research, we built a process of producing fresh cheese using whole milk powder as a material and citric acid as a coagulant agent. - Using citric acid for cheese production has great potential for industrial scale application as it can help simplify the acidification process, reduce production costs and time leading to significant economic benefits.. - Citric acid with CAS number is 77-92-9.. - Fresh cheese preparation. - The chemical composition of the reconstituted milk solution was determined as: protein content 4.36%, lipid content 3.44% and moisture content 84.93% (TS = 15.07%).. - a) MTGase concentration: Reconstituted milk (300 g) after heat treatment was lowered to the temperature of the enzyme treatment (37 ° C).. - b) Temperature: While the enzyme concentration (2.0 IU/g protein) was kept constant, the temperature of the mixture of reconstituted milk-enzyme was varied in a range from 30 to 50 °C (30. - Then, citric acid at investigated concentrations was added to the mixture until the protein precipitated completely (pH = 4.6).. - The quality properties (The yield of fresh cheese production, cheese solids yield, whey separation, texture profile analysis and sensory evaluation) of the samples were determined.. - The yield of fresh cheese production.. - 𝑚� 0 was the weight of reconstituted milk solution (g).. - The CSY value is understood as the ratio of the amount of solids recovered in the cheese product to the initial solids weight [9]. - Where, H was The yield of fresh cheese production, TS cheese was the total solid content of cheese. - TS milk was the total solid content of reconstituted milk. - The texture characteristics of the cheeses were analyzed by a Broofield (USA) CT3 texture analyzer. - Fresh cheese samples were kept refrigerated (4 ± 2 °C) in separate plastic containers until analyzed. - The samples were taken out of the refrigerator about 1 hour before being analyzed and kept in the box, then cut into cylindrical blocks (diameter 2.5 cm, height 2 cm). - (b) test speed of 1.0 mm / s. - (c) pretest speed of 2.0 mm / s;. - smoothness of the cheeses. - The term ‘‘flavour’’ has many definitions but within this study, this term will be defined as the ‘‘impressions perceived via the chemical senses from a product in the mouth’’ [15]. - Sensory evaluation sessions were conducted in the individual booth under fluorescent light. - The colour space for the fresh cheese samples was determined by a CR-400 chroma meter (Minolta, Japan) according to Mokrzycki and Tatol . - The colour parameters of MTGase-treated samples were compared with those of the non-enzyme treated cheese.. - (4) Where, (L o , a o , b o ) and (L i , a i , b i ) were colour parameters of the non-enzyme treated cheese, and the enzyme-treated samples, respectively. - 3 RESULTS AND DISCUSSION 3.1 Results in acid coagulation process A) Effect of temperature of citric acid coagulation process on fresh cheese quality. - The temperature of citric acid treatment had a negligible effect on fresh cheese yield (Table 1). - However, during the making process, we found that, at the temperature of 37°C, the protein precipitate was quite sticky, leading to difficulties in manipulation during whey separation, loss of dry matter on the surface of the tools…. - Therefore, 50 ° C was selected for the citric acid coagulation in the next following experiments.. - Effect of temperature in citric acid coagulation process on some fresh cheese qualities Temperature, oC H. - Effect of citric acid concentration on cheese yield and texture properti es Citric acid. - B) Effects of citric acid concentration on cheese quality. - The analytical results (Table 2) showed that, when the citric acid concentration increased from 1.0% to 2.0%, the recovery efficiency (H. - However, when the concentration of citric acid increased to 3.0%, the recovery efficiency and the dry matter content in cheese decreased (p <0.05). - However, this factor did not significantly affect the texture properties of the product (hardness, springiness and adhesiveness).. - Bankar when authors did the research to determine the effect of different types of acids, including citric acid, tartaric acid and malic acid each at 2, 3 and 5% concentrations on the quality of paneer made using reconstituted milk. - The results also showed that using 2% citric acid. - to coagulate milk proteins gave statistically comparable quality parameters so that the concentration of citric acid of 2.0% was selected as the most suitable level of coagulant for fresh cheese production.. - The results (Table 3) showed that when the concentration of the enzyme MTGase increased from 0.5 to 2.0 (IU/g protein), the quality parameters including solid content (TS cheese. - The increase in the MTGase levels could lead to an abundance of linkages in the gel network which might compete and break each other [19].. - The results of texture analysis (Table 3) showed that beyond springiness, hardness and adhesiveness of fresh cheese products supplemented with MTGase significantly changed among samples. - be explained by the effect of enzyme addition which might increase the water- holding capacity and strength of the gel through protein cross-linking [20], and emulsification [21], thereby helping to improve the texture of the fresh cheese product. - Consequently, weakening the gel network and reducing the quality of the cheese texture.. - From the analytical results we found that using enzyme MTGase concentration of 2.0 IU/g protein gave the better quality properties for the fresh cheese product. - The hardness of 380 g wasn't higher than the value in the products of the same type (480 g for Quark [22].. - B) Effect of temperature in enzymatic treatment on cheese quality. - The experimental results (Table 4) showed that when the temperature of the enzyme treatment increased, the yield of the product (H. - Treatment temperature seemed to not affect the texture of the cheese product. - Therefore, 37 °C was selected as the temperature for reconstituted milk treatment with MTGase during the production of fresh cheeses.. - Effect of MTGase concentration on the quality of fresh cheese MTGase conc.,. - C) Effect of enzyme-treated time on cheese quality. - Therefore, enzyme processing time has a significant impact and is a key factor in cheese production to avoid the formation of excessive protein cross- linking that leads to deterioration of the structural properties of the final product [23].. - From the results, enzyme-treated time of 2 hrs was chosen for fresh cheese production.. - Based on the experimental results, the technological process of manufacture of fresh cheese was created and presented in Figure 2.. - Flowchart of technological process of manufacture of fresh cheese coagulated by citric. - 3.3 Quality properties of fresh cheese Fresh cheese sample was produced under the conditions of MTGase treatment above (Figure 2). - As a result, reconstituted milk from whole milk powder caused the high fat content of the cheese. - The microstructure of fresh cheese coagulated with enzyme (M2) forms micelle casein chains linked together in the interstitial space of various sizes and. - the liquid phase is fixed in the protein gel network. - Meanwhile, the gel structure of the enzyme-treated fresh cheese sample (M1) was more homogeneous, fatty globules are evenly distributed in the protein gel network. - 3.4 Changes in fresh cheese quality during storage. - Some of the quality parameters of citric acid-coagulated fresh cheese samples with MTGase treatment (M1) and without enzyme treatment (M2) are shown in Table 7. - However, the analytical results showed that in the weeks which followed (day 7-28), there was more whey separated from the M2 samples than that from M1. - This synergy is spontaneous and is understood to be a contraction of the gel without any external force acting, resulting in reordering of the gel network and causing the whey to separate.. - Fresh cheese Not detected Not detected. - SEM images of fresh cheese samples. - M1 - Fresh cheese with enzyme, M2 - Fresh cheese without enzyme. - Quality properties of fresh cheese samples with/without MTGase. - M1 - Fresh cheese with enzyme, M2 - Fresh cheese without enzyme Analytical results (Table 7) showed that. - the average sensory evaluation scores of appearance, texture and flavour changed similarly between two fresh cheese samples (M1 and M2) during storage. - However, sensory scores tended to decrease in the final weeks of storage (from day 21 to 28).. - On the strength of this study, the application of citric acid as a coagulant. - However, the efficiency of fresh cheese produced by this method (12.81%) is still low, lower than that of fermentation methods [2]. - The fresh cheeses that are coagulated by citric acid have the quality properties met CODEX STAN 221-2001 for unripened cheese.. - Effect of microbiological transglutaminase on selected physicochemical properties of tvarog. - Effect of Milk Fat Replacement with Vegetable Oil and/or Whey Protein Concentrate on Microstructure, Texture and Sensory Characteristics of Fresh Soft Cheese. - Utilization of polysaccharides to modify salt release and texture of a fresh semi hard model cheese.. - Effect of different coagulants at varying strengths on the quality of paneer made from reconstituted milk.. - Effect of transglutaminase on quality properties of fresh cheese
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