Effects of partially replacing skimmed milk powder with dairy ingredients on rheology, sensory profiling, and microstructure of probiotic stirred-type yogurt during cold storage.

This study aimed to evaluate the quality of stirred-type skim milk probiotic yogurt fortified by partially replacing skim milk powder (SMP) with whey protein concentrate (WPC) and sodium caseinate (Na-CN) during cold storage for 28 d compared with nonfortified yogurt. The rheological properties (as measured using dynamic oscillation) and sensory profiles of probiotic yogurts were greatly enhanced when SMP (i.e., 45%) was replaced with WPC and Na-CN. Higher values of mechanical parameters related to storage and loss modulus and consistent microstructure were found in the fortified yogurts. The acidification profile was not affected by supplementation of the solids in the milk base, and the viable counts of probiotic microbiota were high and satisfactory. These positive characteristics of probiotic yogurts were maintained until the end of the storage period. The microstructure of the fortified yogurt showed some differences compared with the nonfortified product, which were due to changes in chemical composition of the milk base in addition to the colloidal characteristics of the product.

Fermented milks: a historical food with modern applications--a review.

BACKGROUND: : This paper was presented at the symposium which was organized by Instituto Danone Mexico in May 2001, and it provides an overview of the current scientific knowledge on fermented milks concerning the historical developments, manufacturing stages, classification of such products, and nutritional aspects. Particular attention has been paid to the human health benefits associated with the consumption of these products, the use of probiotic starter cultures and their industrial applications, and the significance of using a trained sensory panel for the evaluation of probiotic fermented milks made with different commercial blends of starter cultures. The paper also highlights the future research areas for the exploitation of starter microflora (Lactobacillus, Bifidobacterium and Enterococcus species) in fermented milk products. CONCLUSION: : This review indicates that the complex metabolism of the starter cultures is well established; however, more information is still needed on specific microbial metabolites such as polymerization of milk sugars for the production of exopolysaccharides and the modification of the milk peptides and secretion of bacteriocins. More clinical studies are still required to establish the 'functional' health benefits of probiotic fermented milks to humans.

Yogurt: Technology and Biochemistry 1.

This review considers the physical and chemical changes which occur during yogurt manufacture as a result of processing and microbial fermentation. Changes produced during processes, such as heat treatment and physical manipulations, are reviewed. Microbial fermentation is discussed in terms of the characteristics of the yogurt organisms, Lactobacillus bulgaricus and Streptococcus thermophilus , and the biochemical reactions involved in carbohydrate metabolism, flavor production, proteolysis and lipolysis.

Yogurt: Nutritive and Therapeutic Aspects.

This review deals with the nutritive value of yogurt in terms of its chemical composition, vitamin content and digestibility. The reported therapeutic benefits of yogurt for gastrointestinal disorders, coronary heart disease and other maladies are also discussed.

Comparative Studies of Casein Breakdown in Cheddar Cheese Manufactured from Lactose-Hydrolysed Milk.

Scottish Cheddar cheese (12 trials) was produced from full-fat milk and from the same milk treated with different preparations of (ß-D-galatosidase. Appreciable hydrolysis of the casein fractions was evident in 6-month old Cheddar cheese using lactose hydrolysing enzyme containing a high level of natural protease. Lactose hydrolysis of milk up to 60% slightly accelerated the ripening process of Cheddar cheese, but greater judge preference of the enzyme-treated cheese was reported by the taste panelists as compared with the control.