Effect of oat milk pasteurization type on the characteristics of yogurt

Abstract

The aim of this study was to produce set-type non-dairy yogurt from oat milk pasteurized by thermal (T) and UV-C (coiled-tube type)-assisted thermal (UV-C-T) processes. The yogurts were produced from untreated, T(63 degrees C, 30 min) and UV-C-T-treated (10 cycles, 77.67 J/mL, 60 degrees C) oat milk by lactic acid fermentation and their microbiological, physicochemical, textural and sensorial changes were monitored for 21 days. The reduction in E. coli K-12 was ca. 5 log cfu/mL for both T and UV-C-T treated samples. Yogurts from UV-C-T-treated oat milk had the highest pH (5-6) and the lowest syneresis value during the storage time. L* (60.9 +/- 0.1) and b* (4.9 +/- 0.1) values of yogurts from UV-C-T-treated oat milk were lower compared to untreated and T-treated oat milk. Yogurts from UV-C-T-treated oat milk had higher hardness (g) and adhesive forces (g) values than the untreated and T-treated yogurts during the storage time. Moreover, there was no significant difference (P < 0.05) in terms of overall acceptability of yogurts made from untreated, UV-C-T- and T-treated oat milk. Results showed that the use of UV-C-T-treated oat milk has potential to improve the characteristics of the final product.