Aplicação de transglutaminase na produção de bebida láctea fermentada com alto teor de soro

Abstract

Fermented dairy drinks have had their consumption increased due to their more affordable cost, however, the sensorial characteristics of these are affected mainly by the higher serum content. In order to maintain and add desirable functional and sensory properties to the final product, additives are used, among them, the transglutaminase enzyme of microbial origin (MTG), which acts in the formation of intra- and intermolecular cross-links between proteins, giving greater stabilization of the network of gel. Thus, the objective of this work was to evaluate fermented dairy beverage plus microbial transglutaminase enzyme, varying the maize starch levels of modified maize, gelatine and guar gum in the formulations with subsequent physical-chemical evaluation. A total of five formulations consisting of reconstituted milk and whey powder reconstituted at a ratio of 1: 1, ranging from friend, gelatin and gum were determined and such samples were produced with and without addition of MTG. The amount of enzyme added was established on the protein content presented in the nutritional table of milk and whey powder. Analyzes of pH, lactic acid content, total titratable acidity, proteins, total solids and syneresis were performed. The values of titratable acidity and the percentage of lactic acid ranged from 5.424 to 8.396 and 0.491 to 0.753 respectively in analysis on day 3, 5 and 7 after manufacture. These have demonstrated that all formulations tend to stabilize as to the production of acids and consequent reduction of pH from the fifth day of shelf life. However, pH showed significant variation (p <0.05) between the values obtained during the three days analyzed. The protein content of the formulations was between 1.73 and 1.86 grams in 100 grams of product, the lowest content being observed in formulations which did not contain gelatin. The percentages of solids showed no difference between the formulations with and without enzyme, varying between 17.629 and 18.706%. Regarding syneresis, the formulation containing gum and gelatin (GO / GE) with and without addition of the MTG enzyme did not show syneresis on the days of analysis, which demonstrates the formation of a gel network with greater water retention capacity. In contrast, the starch-containing formulations were the ones that presented the most syneresis due to retrogradation of the starch. In general, the percentage of MTG used did not significantly affect the results obtained, which may show that in small amount as an employee (0.006%), this enzyme does not have the capacity to act as presented in other studies, improving desirable characteristics such as reduction of syneresis.