FUNCTIONAL AND QUALITY CHARACTERISTICS OF FRUITY PROBIOTIC FERMENTED MILK BEVERAGE (SMOOTHİEE LIKE) PRODUCED FROM DIFFERENT MILKS

Project no. 23805 · Status: Kapanmış · 2022

Summary

In this thesis study, the physical, chemical, microbiological, and sensory properties of three different fermented milk beverages similar to smoothies produced using different ratios of cow and goat milk (%100 cow (İ), %50 cow-%50 goat (İK), and %100 goat (K)) with the addition of chia and blueberries were attempted to be determined. Samples stored for 21 days at 4 °C underwent analyses for dry matter, ash, titratable acidity, pH, fat, color, texture, viscosity, DPPH and protein on days 1, 7, 14, and 21 of storage. Microbiological analyses were conducted to enumerate Lactobacillus acidophilus, Bifidobacterium bifidum, and Streptococcus thermophilus bacteria.As a result of the findings obtained from the analysis; all three products were found to comply with the Turkish Food Codex Fermented Dairy Products notification. Sensually; while the I and IK samples were liked more, the K sample was less liked as a result of sensory evaluations, and the reason for this was that the unique smell of goat milk was less accepted by consumers (p <0.05). On the other hand, in the IC sample, cow's milk suppressed the odor and the IC sample was found to be more drinkable in terms of consistency and viscosity results. The reason why the consistency of sample K was found to be more fluid than the other samples was explained by the fact that the casein micelles of goat milk are less resistant to heat. When microbiological counts were examined, it was determined that the Lactobacillus acidophilus, Streptococcus thermophilus and Bifidobacterium bifidum numbers of sample K were lower than the other two samples. The difference in L* value between smoothies produced from different milks was found to be statistically significant (p<0.05). The increase in redness is thought to be potentially due to the anthocyanins found in blueberries, which give the purplish color to the products with the addition of blueberries. On the other hand, the fact that there was no change in the a* value during storage showed the stability of anthocyanins against refrigerated storage. Antioxidant activities of smoothies produced with blueberries and chia seeds were first determined in the produced samples by DPPH% inhibition analysis, then in vitro digestion was performed and DPPH% inhibition analysis was performed on the same samples after stomach and small intestine digestion. In the 1st and 21st day analyses, different milk usage was found to be statistically significant among the products (p<0.05). The products are listed as K>İK>İ. There is no difference between the DPPH% reduction values of smoothies produced in vitro digestion and the values obtained after gastric digestion. This shows that the antioxidant substances coming from chia seeds, blueberries, milk and culture that we use in our smoothie are not affected by stomach acidity. On the other hand, in our analysis from the post-small intestine section, DPPH% inhibition values were low. The products were digested in vitro and fluctuations were observed in the microbiological count results. When we look at the literature, there are few studies on this subject. It is thought that our study will shed light on new studies and functional product range in this respect.

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