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.
: 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.
: 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.
Moroccan traditional dairy products, especially the fermented types, have been the pride of culinary tradition for centuries. It is evident that these products have played a major role in the diet of ...communities in the rural region. Among those,
lben,
smen and
jben are the most common and are being increasingly marketed throughout the country in informal ways. They should be produced and their chemical composition should be adapted to the international economic environment and in compliance with food safety requirements. Traditional methods of manufacture should take advantage of technical progress to assure a reasonable margin of benefit, and at the same time conserve the authenticity and origin(s) of these products. The requirements for an adequate and sustainable technology transfer of three traditional Moroccan fermented dairy products (i.e.
lben,
jben and
smen) are discussed in the scope of the transfer of these products’ technologies to small and/or medium industrial scale. Schemes to standardize the manufacturing stages of
lben,
smen and
jben making are proposed. Emphasis is put on the relevance of the role of the starter cultures as the missing part in the traditional methods of manufacture to ascertain appropriate transfer with respect to the maintenance of sensory profiling, nutritional quality and physical properties of the original products. Relevant research and development activities are suggested; regulatory aspects to define objectively the quality criteria and to protect the authenticity of the product are also discussed.
The acidification rates of
Lactobacillus delbrueckii subsp.
bulgaricus (Lb),
Lactobacillus acidophilus (La),
Lactobacillus rhamnosus (Lr), and
Bifidobacterium animalis subsp.
lactis (Bl) in ...co-culture with
Streptococcus thermophilus (St) were studied in
Minas frescal cheese whey. Effects of the co-culture composition and the final pH values on the kinetic parameters of acidification, post-acidification and counts of health promoting micro-organisms were also studied. Fermentation time to reach pH 4.5 was longer when St–Lr co-culture was used, while St–Lb had the shortest fermentation time when compared with the other co-culture combinations. All products showed development of acidity during the storage period and lowest values had been observed employing St–Bl co-culture. The technological interest of using
M. frescal cheese whey for the production of a probiotic lactic beverage is discussed in this article.
The main objectives of the present study were (a) to study the effects of the different combinations of
Lactobacillus delbrueckii subsp.
bulgaricus (Lb),
Lactobacillus acidophilus (La),
Lactobacillus ...rhamnosus (Lr), and
Bifidobacterium animalis subsp.
lactis (Bl) in co-culture with
Streptococcus thermophilus (St) on the rate of acid development in milk and milk-whey mixture, and (b) the effect of the level of the total solids of the different bases on the acidification profile and viability of potential health-promoting micro-organisms. The co-culture of St-Lr showed the lowest values
V
max in all bases; while the co-culture St-Bl had high
t
V
max in milk and whey bases (12 and 10
g/100
g, respectively). Co-cultures St-La and St-Lb reached
V
max at pH 5.5, while St-Lr and St-Bl at pH 5.91. Fermentation time to reach pH 4.5 was longer when St-Lr co-culture was used, while St-Lb had the lowest value. All the products had slight development of acid during the storage period, and lowest values were observed when the St-Bl co-culture was employed. Lb, Bl and St cultures had high counts at pH 4.5 in the three bases. The total solids affected the viability of Lb and La. The technological interest of these combinations is discussed in this article.
Ovine and caprine milk are widely produced in semi-arid countries, and mainly utilised for milk consumption and the manufacture of a wide range of cheeses, fermented milk products (e.g. liquid, ...viscous, concentrated and dried) and to a lesser degree milk powder. The primary aim of this review is to provide a critical analysis of the main components of milk from different ovine and caprine breeds for the manufacture of fermented milk products, i.e. traditional and industrial. This paper reviews the latest scientific developments in fermented milks, including probiotic products, and recommendations to improve the characteristics of the final product(s). Although ovine milk is successfully used to manufacture many fermented milk products, the solids content of milk from certain breeds of caprine needs to be fortified to enhance the protein content and modify the processing conditions to ensure products acceptable to the consumer.
Set-type yoghurts were produced from goat's milk cross-linked by microbial transglutaminase (TGase) using different amounts (1, 2 or 3U/g protein), and the control yoghurt did not contain any TGase. ...Fresh and stored yoghurts (14 days) were examined for sensory profiling, instrumental texture analysis, syneresis and microstructure to study the influence of TGase concentration and storage time on the quality of the experimental products. TGase yoghurts (fresh and stored) had higher sensory scores, higher readings for texture measurements (i.e. firmness) and a lower volume of syneresis than the control product. In general, the higher the amount of added TGase used in the milk base the firmer the fresh yoghurt became, the lowest syneresis was observed and the highest sensory score was awarded by the taste panellist. Nevertheless, the best sensory score of fresh yoghurt was awarded to the product made with added 2U TGase/g protein, and for stored yoghurts containing 2 and 3U TGase/g protein, but syneresis of the product containing 3U TGase/g protein was higher than the other experimental yoghurts. The firmness of the fresh experimental yoghurts (2 and 3U TGase/g protein) was similar, and the stored products exhibited slight tendencies to syneresis and the firmness of the product was slightly higher, but the sensory score was lower. The protein matrix of the experimental yoghurts was more compact, and consisted of smaller casein micelles/aggregates than those of the control yoghurt. Modification of the goat's milk with microbial TGase improved the sensory quality, textural characteristic, and reduced syneresis of set-yoghurt when compared with the control product. Overall, the results suggest that best set-type goat's milk yoghurt was made using 2U TGase/g protein.
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