Growth, Proteolytic, and ACE-I Activities of Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus and Rheological Properties of Low-Fat Yogurt as Influenced by the Addition of Raftiline HP

• Published in: Journal of food science 2008-09, Vol.73 (7), p.M368-M374
• Main Authors: Ramchandran, L, Shah, N.P
• Format: Article
• Language: English
• Subjects: Acetic Acid - analysis; Angiotensin-Converting Enzyme Inhibitors - metabolism; angiotensin-I converting enzyme; Bacteria; Biological and medical sciences; Colony Count, Microbial; enzyme inhibitors; Enzymes; Fat Substitutes - chemistry; Fermentation; fermented foods; firmness; Food industries; Food Microbiology; food pathogens; food quality; Food science; food storage; Fundamental and applied biological sciences. Psychology; Hydrogen-Ion Concentration; Inulin - chemistry; Lactic Acid - analysis; Lactobacillus delbrueckii - growth & development; Lactobacillus delbrueckii - metabolism; Lactobacillus delbrueckii subsp. bulgaricus; low fat dairy products; Milk and cheese industries. Ice creams; Milk Proteins - analysis; peptidyl-dipeptidase A; Physical growth; proteolysis; proteolytic; Raftiline; Raftiline HP; rheological properties; Rheology; shear strength; skim milk; starter cultures; Streptococcus thermophilus; Streptococcus thermophilus - growth & development; Streptococcus thermophilus - metabolism; Studies; texture; whey; Yogurt; Yogurt - analysis; Yogurt - microbiology
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1750-3841.2008.00889.x

This study investigated the influence of incorporating Raftiline HP® on the pH, growth, proteolytic, and angiotensin-I converting enzyme inhibitory activities and on spontaneous whey separation, firmness, and rheological properties of low-fat yogurts during storage for 28 d at 4 °C. Three types of yogurts were prepared from skim milk containing 0% (YI0, control), 2% (YI2), and 3% (YI3) Raftiline HP, respectively. The incorporation of Raftiline HP improved the growth of starter organisms, particularly that of Lactobacillus delbrueckii ssp. bulgaricus, resulting in shorter fermentation time. There was a significant improvement in total proteolysis, which was highest in yogurt containing 3% Raftiline HP. The ACE inhibitory activity was maximal in YI3 compared to YI2 and YI0. Incorporation of Raftiline HP did not affect whey separation and firmness of the low-fat yogurts. All these products were more fluid like with distinct pseudoplastic properties and lesser ability to resist deformation upon applied shear.