Evaluation of Various Properties of Symbiotic Yoghurt of Buffalo Milk

Abstract

In present study the set-type yoghurt samples were prepared from buffalo milk, Lactobacillus acidophilus and Bifidobacterium bifidium as probiotics and lactoluse, oligofructose and inulin as prebiotics. Changes in pH value, syneresis and probiotic counts along with sensorial properties were tested in all of yoghurt samples after preparation up to 21 days at 4C. According to the results of pH test, post acidification with a range of 4.53-3.93 was observed. Using prebiotics simultaneously led to the significant lower syneresis rate during the storage. Probiotic bacteria used in this study were found to have survived above 7 log cfu/mL throughout the study period. The present study proved that prebiotics improved physicochemical properties and enhanced probiotic bacteria survival in the experimental yoghurts. On the other hand, control and probiotic yoghurts were preferred by the sensory panel over symbiotic yoghurt. PRACTICAL APPLICATIONSThere is a high demand for consumption of buffalo milk and its derived products worldwide. Buffalo yoghurt is a good carrier for developing symbiotic yoghurt. Probiotics just in adequate amounts can have beneficial effects for the host and therefore their viability should be monitored throughout storage time of symbiotic yoghurt, as they must survive in the gut environment. Sensory properties of yoghurt are important factors for its popularity as well. Therefore symbiotic yoghurt was made using Lactobacillus acidophilus and Bifidobacterium bifidium along with prebiotics including inulin, lactulose and oligofructose to settle the most beneficial probiotic-prebiotic combination, that have at least the minimum requirement of probiotics as well as good sensory properties for development of a marketable symbiotic yoghurt of buffalo milk.

Potential Using of Ulvan Polysaccharide from Ulva lactuca as a Prebiotic in Synbiotic Yogurt Production

“…in synbiotic yogurt increased in enhanced samples with 1 and 2% ulvan polysaccharide; which confirmed the synergistic effect between these bacteria due to their mutual interactions and the addition of ulvan polysaccharide as a prebiotic. These results are compatible with that demonstrated before by Gustaw et al [33] and Ehsani et al [34] who confirmed that the incorporation of inulin, oligofructose, and other types of fibers as prebiotics improved the growth of, Bifidobacterium sp. and Lactobacillus acidophilus probiotic bacteria.…”

“…The further decreasing of pH during post-acidification caused these reductions in the viability of probiotic bacteria in synbiotic yogurt; also, Bifidobacterium was more susceptible to aerobic conditions during the cold storage. These findings are consonant with that observed by Eskandari et al [28] Gustaw et al [33], and Ehsani et al [34].…”

“…is slow in milk, because of its slight proteolysis activity and deficiency of non-protein nitrogen (NPN) in milk, which makes milk is an inappropriate medium for growth of Bifidobacterium sp. and coexistence with Lactobacillus acidophilus enhanced its growth [34].…”

“…These results in the same trend of Gustaw et al [33] who found yogurt enhanced with 1% inulin had the lowest pH values during the refrigeration storage. Ehsani et al [34] also mentioned that the prebiotic such as lactulose, inulin and oligofructose stimulate the activity and growth of probiotic bacteria and consequently its acids production, which increased the acidity and reduced the pH values in the resultant yogurt during the storage time. On the other hand, Moayednia [35] found a significant decrease in the pH value after 8 days of cold storage of yogurt; and reported that results were logical because the β-galactosidase of viable or nonviable cells of starter culture was still active.…”

“…The important factor for the dairy products containing probiotic bacteria particularly the yogurt which is an acidic environment is the survival counts of the used probiotic bacteria. There are many factors affecting their survivability in yogurt such as the probiotic strains, inoculation percentage, conditions of culture growth, fermentation time and temperature, and the acidity rate in yogurt [34].…”