Effect of milk types on the attributes of a glutinous rice wine-fermented yogurt-like product

Abstract

This study was conducted to analyze the effect of milk types on the attributes of the glutinous rice winefermented yogurt-like product named Kouwan Lao (KWL). Four types of raw milks were used in this study, including high temperature, long time (HTLT: H milk), HTLT milk supplemented with 3% skim milk powder (S milk), pasteurized milk (P milk), and ultra-high temperature milk (U milk). Microbiological compositions of the fermented glutinous rice and KWL at different stages were analyzed using PCR-denaturing gradient gel electrophoresis and gene sequencing based on 16S rRNA and 26S rRNA. The physicochemical properties of KWL samples were determined, and textural properties of those were analyzed using a texture analyzer (Jiawei Innovation and Technology Co. Ltd., Zhejiang Province, China). The microstructure of KWL samples was observed using scanning electron microscopy. The results showed that the milk types had significant influences on the bacterial composition of KWL. In the curdling process, the predominant bacteria of H, S, P, and U KWL samples were Lactobacillus brevis, Janthinobacterium sp., Lactobacillus casei, and Streptococcus agalactiae, respectively. In the ripening process, the main strains in H KWL were Enterococcus faecium and Pediococcus pentosaceus. Lactobacillus casei and Lactobacillus paracasei were the dominant bacteria of U KWL. Lactobacillus casei was the main strain of P KWL, and no bacteria were detected in S KWL. Saccharomyces cerevisiae was the dominant fungus of KWL, and no significant effect of milk types on fungal composition of KWL was found. The results of physicochemical properties showed that significant differences in protein contents were found in the KWL samples, and P KWL had the highest protein content. The fat content of U KWL was significantly higher than that of samples from the other 3 groups. The U KWL and P KWL showed lower moisture than that of the other 2 KWL samples. In addition, no significant difference in pH value was found in all samples. The results of texture analysis and microstructure showed that compared with other 3 types of KWL samples, the related mass parameters of U KWL were more advantageous and improved significantly with the increase of the heat treatment temperature of raw milk and the addition of skim milk powder. Our findings revealed the effects of milk types on microbial composition, physicochemical properties, textural properties, and microstructure of KWL, and provided a basic theory for the optimization and industrial production of KWL.

Effect of starter inoculation proportions on the attributes of a superior new variety Osmanthus glutinous rice‐fermented milk beverages

“…Fermented dairy products are popular with dairy processors and consumers because of their unique taste and flavour, convenient logistics, transportation and storage (Gong et al ., 2020; Mathur et al ., 2020). With the growth of demand for no artificial ingredients, there is an urgent need to develop a variety of natural fermented dairy products to provide consumers with a new experience of being delicious, healthy and convenient (Khorshidian et al ., 2020; Zhu et al ., 2022).…”

Saccharomyces cerevisiae improves rennet-induced gelation of ultra-high temperature milk

“…Ultra-high temperature milk is produced by heating milk at high temperature (in the range of 135-150°C) for a short period of time (1-10 s; Deeth, 2020). Ultrahigh temperature milk is widely used in acid-induced gelation (Nguyen et al, 2017;Gong et al, 2020) but not in rennet-induced gelation. It is well known that heating milk at temperatures exceeding 65°C results in changes to the physical and chemical properties of casein micelles, such as denaturation of whey proteins, which impairs the rennet-induced gelation of milk (Gamlath et al, 2018(Gamlath et al, , 2020Lin et al, 2018).…”