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Influence of milk protein cross‐linking by transglutaminase on the rennet coagulation time and the gel properties
Author(s) -
Domagała Jacek,
NajgebauerLejko Dorota,
WieteskaŚliwa Ilona,
Sady Marek,
Wszołek Monika,
Bonczar Genowefa,
FilipczakFiutak Magda
Publication year - 2015
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.7534
Subject(s) - rennet , tissue transglutaminase , coagulation , food science , milk protein , chemistry , chymosin , chromatography , biochemistry , enzyme , casein , medicine
Abstract BACKGROUND Transglutaminase ( TGase ) modifies milk proteins by cross‐linking of caseins, with increased cheese yield being the main technological benefit. In the present work the influence of TGase addition in different concentrations (0, 1, 2 and 3 U g −1 protein in the system) and under different incubation conditions (0 h, 40 °C/2 h, 25 °C/4 h and 5 °C/16 h) on the rennet coagulation time ( RCT ) and the comprehensive rennet gel properties were investigated. RESULTS Modification of milk proteins by TGase in a concentration‐dependent manner caused longer RCT and lower gel firmness. The highest TGase concentration and incubation at 40 °C for 2 h resulted in the longest RCT and the lowest gel firmness. Rennet gels obtained from TGase modified milk were characterised by significantly lower values of texture parameters, lower syneresis and were composed of smaller casein micelles, thinner chains and smaller clusters than those obtained from the control milk. The content of whey proteins in the gel from modified milk was higher and the content of individual casein fractions in the milk samples and rennet gels decreased upon TGase modification. CONCLUSION Rennet cheese with modified textural and nutritional properties and improved yield can be obtained upon TGase modification but simultaneous addition of rennet and TGase is recommended. © 2015 Society of Chemical Industry