Kefir production fortified with chestnut milk

In the present study, microbiological, physico-chemical, textural, sensory and antioxidative properties of kefir produced with chestnut milk and reconstituted milk mixture as well as with commercial culture and grain were investigated. Optimization of chestnut milk production was performed using the dilution rate (x_1), dilution temperature (x_2), pasteurization time (x_3) and pasteurization temperature (x_4) variables according to response surface method (RSM). According to the optimization results, the dilution rate of 1/4, dilution temperature of 37,562°C, pasteurization time of 24,996 minutes and pasteurization temperature of 84,433°C were used in chestnut milk production.Kefir production was carried out by adding chestnut milk at the rate of 0, 10, 20, 30, 40, 50 and 100 % to reconstituted milk.Lactobacillus cell counts in kefir samples determined between 7,24-9,51 cfu/mL; whilst Lactococcus counts varied between 7,27-10,33 cfu/mL; acetic acid bacteria counts 5,08-8,75 cfu/mL; yeast population 1,48-7,90 cfu/mL; titratable acidity 0,20-1,16 %; serum separation 0-14,50 mL/25 g; dry matter 9,02-14,29%; protein 2,20-4,40 %; fat 0,13-0,47 %;acetaldehyde 0,82-3,66 mg/100 mL;diacetyl value 1,11-117,28 mg/100 mL; ethyl alcohol 26,61-146,51 mg/100 mL; carbon dioxide 92,40-507,10 mg/100 mL; ABTS 8,62-37,05 mg/100 mL; FRAP 5,31-25,84 mg/100 mL; DPPH 8,67-24,26 mg/100 mL; and total phenolic compounds 77,67- 341,47 mg/100 mL. It has been observed that arginine, leucine and alanine amino acids; oleic, palmitic and linoleic fatty acids; citric, formic and oxalic organic acids; K, Ca and P elements and the vitamin C, A and E values were high in kefir samples. The differences between color values and textural parameters in samples were found as statistically significant (p<0,01). Depending upon the obtained outcomes, one could state that chestnut milk has improved the properties of kefir in terms of functional nutrients and technology, and its use with reconstituted milk has high/significant consumer acceptability.