title: Enzymatic cross-linking of soy proteins within non-fat set yogurt gel.
abstract: Soy proteins as the health-promoting ingredients and candidate fat substitutes in dairy products are good substrates for the cross-linking action of the enzyme transglutaminase. Non-fat set yogurt samples were prepared from the milks enriched with soy protein isolate (SPI) and/or treated with the enzyme transglutaminase. The highest titrable acidity was recorded for the yogurt enriched with SPI and treated with the enzyme throughout the cold storage for 21 d. SPI-enrichment of yogurt milk increased the water holding capacity. Although enrichment with SPI did not influence the count of Streptococcus themophilus, increased that of Lactobacillus bulgaricus ∼3 log cycles. The enzymatic treatment of SPI-enriched milk however, suppressed the bacteria growth-promoting influence of SPI due probably to making the soy proteins inaccessible for Lactobacillus. SPI-enrichment and enzymatic treatment of milk decreased the various organic acids content in yoghurt samples; influence of the former was more significant. The cross-linking of milk proteins to soy proteins was confirmed with the gel electrophoresis results.
authors: Department of Food Science and Engineering, Faculty of Agriculture,Urmia University,Urmia,Iran.
authors: Rana
authors: R
authors: Soleymanpuori
authors: Department of Food Science and Engineering,University College of Agriculture and Natural Resources, University of Tehran,Karadj,Iran.
authors: Ashkan
authors: A
authors: Madadlou
authors: Department of Food Science and Engineering, Faculty of Agriculture,Urmia University,Urmia,Iran.
authors: Fariba
authors: F
authors: Zeynali
authors: Department of Food Science and Engineering, Faculty of Agriculture,Urmia University,Urmia,Iran.
authors: Asghar
authors: A
authors: Khosrowshahi
mesh_terms: D000818:Animals; D002417:Cattle; D003432:Cross-Linking Reagents / Q000378:metabolism; D018752:Diet, Fat-Restricted; D005524:Food Technology / Q000379:methods; D007778:Lactobacillus / Q000378:metabolism; D008892:Milk / Q000378:metabolism; D030262:Soybean Proteins / Q000378:metabolism*; D048249:Streptococcus thermophilus / Q000378:metabolism; D011503:Transglutaminases / Q000378:metabolism; D015014:Yogurt
chemical_list: D003432:Cross-Linking Reagents; D030262:Soybean Proteins; D011503:Transglutaminases