Search

The aim of this study was to evaluate the consumer acceptance and preference of a novel cheese coagulated with vegetal rennet and microbial transglutaminase (V + TG) as an alternative for lacto‐vegetarian consumers. The evolution of the sensory and instrumental parameters throughout the storage time was studied. Cheese with animal rennnet and microbial transglutaminase (A + TG), vegetal rennet alone (V) and animal rennet alone (A) were also studied as controls. The consumer test showed that the V + TG cheese was preferred and showed high texture and taste acceptance scores. This cheese could be successful for its sensory acceptance and as an alternative for the lacto‐vegetarian market. [ABSTRACT FROM AUTHOR]

The aim of this work was to obtain information about how sensory differences affect consumer acceptability for skim yoghurt obtained with transglutaminase (TG yoghurt). Skim yoghurt fortified with skim milk powder was used as control (Control yoghurt). Sensory descriptors were assessed by a trained panel (n = 16). Acceptance and preference were evaluated by consumers (n = 124). Results showed that TG yoghurt showed a sensory profile different to that of Control yoghurt. TG yoghurt was firmer and less creamy than Control yoghurt. The acceptance index was 59.7% for TG yoghurt and 70.5% for Control yoghurt. Consumers did not show a high rejection towards TG yoghurt. [ABSTRACT FROM AUTHOR]

BACKGROUND Low‐fat or non‐fat yoghurts are popular nowadays. However, their texture is not good and they show considerable syneresis with time. The aim of this research was to evaluate the effect of the application of transglutaminase (TG) to low‐fat yoghurt to determine if similar sensory properties to those of full‐fat yoghurt can be obtained. Methods of adding TG (prior or simultaneous with fermentation), dose, and TG origin were evaluated. Correlations between sensory and physicochemical parameters were assessed. RESULTS: The results showed no significant differences between TG addition methods in terms of the quantitative and qualitative sensory attributes studied. Simultaneous addition of TG was preferred to speed up the process. A dose of 1 U g−1 was selected as optimal. Few differences were detected due to the origin of the TG. They were not significant although some differences were observed in terms of density, bitterness, and syneresis compared with low and full‐fat yoghurts. CONCLUSION: The results showed that sensory parameters cannot be associated with only one physicochemical parameter in yoghurt evaluation. Transglutaminase can be used as a substitute for stabilizers in the production of low‐fat yoghurt, maintaining good sensory properties and avoiding initial syneresis. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of CyTA: Journal of Food is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: BACKGROUND: Currently consumers demand low‐fat or non‐fat yoghurt but their physical properties are less attractive than those of full‐fat yoghurt. It was reported that microbial transglutaminase (TG) can be used in the production of low‐fat yoghurt. The aim of this work was to evaluate the effect of TG on low‐fat yoghurt to improve their physicochemical and textural properties to approach to those of full‐fat yoghurt. Two TG application methods (addition before fermentation or simultaneous addition with the starter), three dose levels and TG origin were evaluated. Results were compared with commercial low‐fat and full‐fat yoghurts. RESULTS: No significant differences between application methods were observed. Simultaneous addition of TG was preferred because additional time‐consuming steps are not required. The best dose was 1 U TG g−1 of protein that allowed a firmness higher (4.25 N) than that of commercial low‐fat (3.05 N) and full‐fat (4.43 N) yoghurts to be achieved. This implies that intermediate values of TG will permit the same firmness as commercial yoghurts to be obtained. It was observed some differences by the TG origin may be due to excipients. CONCLUSION: TG may be used to replace stabilizers in the production of low‐fat yoghurt as it improves texture and avoids initial syneresis. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of Revista Facultad de Ingeniería Universidad de Antioquia is the property of Universidad de Antioquia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this work was to evaluate the production of microbial transglutaminase (MTG) by Streptomyces rnobaraensis in a reduced nutritional medium based on non-commercial potatoes. Initially, the production was studied comparing 3 culture media based on potato: (i) media based on acid hydrolysed potato, (ii) media based on gelified non-hydrolysed potato and (iii) media based on gelified non-hydrolysed potato supplemented with glucose (20 g/L). All media were supplemented with nutrients and inductors of MTG production (yeast extract, peptone, sodium caseinate, glycerol and mineral salts such as sodium phosphate, potassium phosphate, magnesium sulphate). The best medium was gelified non-hydrolysed potato allowed to obtain up to 2.72 U/mL at 96 h. In a second study, it was proposed the substitution of all the nutrients and inductors by exclusively skim milk and glycerol. An experimental design was performed to optimize the composition of milk, potato and glycerol. The economical yield of the process was also evaluated. Fermentations were carried out and samples were taken at 72 h and 96 h. Results showed that the maximum MTG activity was obtained at 72 h. A significant effect of potato and milk on MTG activity was observed, including an effect of interaction between both compounds. Optimal conditions selected were: 600 g/L of skim milk, 40 g/L of potato and 5 g/L of glycerol, yielding a maximum activity of 3.2 U/mL and an economic yield of 8.11 € of MTG/€ of nutrients. The results showed that the medium milk-potato-glycerol was feasible for the production of transglutaminase, obtaining a high MTG activity in a simple natural medium. [ABSTRACT FROM AUTHOR]

New low-cost culture media for microbial transglutaminase production are desired to enhance the economics of its biotechnological production. The aim of this work was to evaluate the production of transglutaminase from enzymatic hydrolysates of potato byStreptomyces mobaraensisin a reduced nutritional medium. An experimental design was performed to optimise the composition of yeast extract (YE), corn steep liquor (CSL) and sodium caseinate (SC) as nutritional supplements. The results showed a significant effect of YE and SC, the effect of CSL being non-significant. Economic yield was also modelled for evaluating the economics of the process. Optimal conditions selected were 10 g/L of YE, 2 g/L of CSL and 13.7 g/L of SC, yielding a maximum activity of 1.128 ± 0.100 U/mL and a transglutaminase economic yield of 3.72 € per € spent in nutrients. The results showed that enzymatic hydrolysates of potato were feasible media for the production of transglutaminase. [ABSTRACT FROM PUBLISHER]

Abstract: Transglutaminase is an enzyme used as food additive to improve the textural properties of proteinaceous foods. The biotechnology industry demands raw materials to prepare growth media for fermentative processes. Non-commercial potatoes are agricultural wastes that can be hydrolysated to be used as substrate for the biotechnological production of transglutaminase. The cost of culture media has a great effect on the final price of the enzyme. This work deals with the design of a plant for transglutaminase production from potatoes and the simulation of the process to evaluate its feasibility. The software “SuperPro designer” was used to simulate the plant. The process is based on our previous works (patent by USC). The designed process includes the following main steps: 1) acid hydrolysis of potato to obtain sugar solutions; 2) fermentation by Streptomyces mobaraensis; 3) freeze drying to obtain a food additives containing transglutaminase. The simulation showed that a small plant with a production rate of 2700kg/yr of food additives containing 100 U/g of transglutaminase is feasible. A total capital investment of $5.4 million was required for construction of a processing, fermentation and recovery plant that would obtain transglutaminase from the potato wastes. Annual operational costs amounted to $1.1 millions for a lifespan of 15 years. The simulation program has detected a bottleneck in the fermentation step, being the bioreactor the limiting equipment. The main raw material, potato, contributed to the overall bulk material cost with only an 18%. The nutrients needed for the fermentation had the main contribution to the overall bulk material cost, being 45%. The profitability analysis showed a payback time of 5 years. The results obtained show that simulation tools are very useful for evaluate the industrial production of biotechnological food additives. The industrial production of transglutaminase by Streptomyces mobaraensis from potato can be a feasible alternative [Copyright &y& Elsevier]

Transglutaminase is an enzyme that catalyses an acyl transfer reaction between γ-carboxamide groups of glutaminyl residues and lysine residues in proteins. Due to this property, this enzyme is used for enhancing textural properties of protein-rich food. The transglutaminase used as food additive is obtained by microorganisms, mainly by Streptoverticillium ladakanum. On the other hand, sugar cane molasses is a viscous liquid rich in noncrystallized carbohydrates (saccharose, glucose and fructose). In this work, the feasibility of using sugar cane molasses as a carbon source for the production of microbial transglutaminase by Streptoverticillium ladakanum NRRL 3191 has been studied. Carbon sources including sugar cane molasses (60 g of total sugars per L), glycerol (60 g/L) and their mixture in a ratio of 1:1 (30 g/L of each) were evaluated. Time course of microbial growth, transglutaminase activity and carbon source consumption were determined every 24 h during 120 h of fermentations at three agitation speeds (200, 300 or 400 rpm). The results showed that with the increase in agitation speed, the biomass concentration increased up to 8.39 g/L in the medium containing sugar cane molasses alone or the mixture of molasses and glycerol. The highest transglutaminase activity was obtained at 400 rpm in the medium containing a mixture of molasses and glycerol, reaching 0.460 U/mL, while in the medium containing sugar cane molasses alone, the activity was 0.240 U/mL, and using glycerol alone it was 0.250 U/mL. These results show that sugar cane molasses is a suitable medium for transglutaminase production when it is combined with glycerol. [ABSTRACT FROM AUTHOR]

White tuna ( Thunnus alalunga ) is a blue fish with nutritional significance and high benefits to health. The aim of this work was to develop white tuna restructured products with reduced-salt (15 g/kg) using transglutaminase. Textural profile analysis, expressible water, dry matter, water activity and colour parameters were measured. In a first study, the temperature effect of the setting phenomenon was evaluated at three conditions: 4 °C/12 h, 25 °C/2 h or 40 °C/20 min. The results showed that texture parameters were improved using transglutaminase at 4 °C/12 h. Considering the results, in a second study the setting at 4 °C was selected and the transglutaminase concentration (150, 300, 450 U/kg) and setting time (6, 12, 18 h) were optimized. The better setting treatment was at 4 °C for 18 h using 450 U/kg of transglutaminase. Restructured products were obtained under these conditions and in a third study the microbial load was evaluated during the storage at 4 °C for 12 days. Different microbiological groups (psychrotrophs, aerobic mesophiles, anaerobes, proteolytic bacteria and Enterobacteriaceae) were measured. The results showed that the manipulation after the cooking step is critical. Overall, it was demonstrated that the restructuring of white tuna is feasible. [ABSTRACT FROM AUTHOR]

Abstract: The restructuring process offers to fish processors the opportunity to obtain new products, taking advantage of both low-value fish species and remains from filleting and other processing operations. However, mechanical and functional properties of restructured products depend on the biochemical and physicochemical properties of muscle proteins, mainly myosin and actomyosin. In this regard, the biochemistry of fish muscle is different from that of mammals and birds. Therefore, fish products must be processed in a different way from red meat or poultry. The main fish products are surimi and restructured products. Fish products can be improved or modified by using hydrocolloids (carbohydrates and protein) as additives. In this review, the modern technology to obtain these products, the applications of hydrocolloids in fish products, and the implications of the increasing demand for healthy, low-salt fish products are discussed. [Copyright &y& Elsevier]

Abstract: The food intake in developed countries is characterized by a deficient consumption of n-3 fatty acids and fiber. In this study, modified beef patties enriched with polyunsaturated n-3 fatty acids and fiber were developed. The texture profile was compared to traditional beef patties, showing lower values for all parameters except springiness. To improve its texture, pretreatments using transglutaminase (TG) and sodium caseinate (C) were assayed by response surface methodology. Mathematical models were obtained and used to determine the effect of TG, C, temperature and time of pretreatment on the texture of beef patties. The overall optimization indicated that a pretreatment with 0.1 U/g of TG at 40 °C for 17 min allowed to have a traditional texture for beef patties enriched in n-3 PUFAs and fiber. The models showed that the addition of caseinate was not needed. Minimal effects of pretreatment were observed on composition, color and cooking loss of the product. [ABSTRACT FROM AUTHOR]

Restructured fish products from the filleting waste from silver carp (Hypophthalmichthys molitrix) were obtained using sodium caseinate (1%), whey protein concentrate (WPC) (1%) or MTGase (0.3%) at different levels of salt (0%, 1% or 2%). The restructured products were obtained by incubating at 40 °C for 60 min and then at 90 °C for 20 min. Changes in the mechanical properties were studied by measuring changes in the textural profile analyses, punch test and torsional test analyses and expressible water. The mechanical properties increased when the salt level was also increased. The mechanical properties of non-salted and low-salt products were increased by using dairy proteins. Sodium caseinate had a greater effect in improving mechanical properties than WPC. MTGase increased expressible water. The results obtained showed that the mechanical properties of low-salt restructured fish products can be improved by using dairy proteins combined with MTGase, with a slight increase in expressible water. [Copyright &y& Elsevier]

The aim of this study was to determine the effect of the rennet source and the interaction of rennet with TG on physicochemical and texture properties of fresh cheese made with pasteurized cow milk. The rennets used were: animal, recombinant chymosin, vegetal or microbial rennet. Cheeses with and without addition of TG was obtained. The rennet source did not affect statistically the activity water and water content of the cheese. The highest yield was obtained using recombinant chymosin. The rennet source showed important effects on texture parameters. Microbial and vegetal rennets increased the adhesiveness of cheeses. Cheeses coagulated with animal rennet were the most affected by the TG treatment, observing a significant decrease in hardness (62.19%), chewiness (75.09%) and springiness (43.75%). The adhesiveness and cohesiveness values also increased significantly. An increase of 0.69% in the yield was achieved when the TG was combined with animal rennet. The TG addition combined with animal rennet can be an effective way to obtain cheese products with innovative textural properties and slightly improved yield. • Cheese was obtained using different rennet sources and transglutaminase. • Rennet source showed important effects on texture parameters. • Microbial and vegetal rennets increased the adhesiveness of cheese. • Transglutaminase addition with animal rennet can obtain cheese with innovative texture. [ABSTRACT FROM AUTHOR]