Effects of the proteins of indica rice and indica waxy rice on the formation of volatiles of sweet rice wine

Abstract

Summary The proteins in the raw materials affect the formation of flavour during fermentation. Among all the fermentation broth of protein fraction in the study, the rice prolamin and albumin effectively promoted floral, honey and fruity characteristics in fermentation with higher level of β‐phenylethyl alcohol, 2,4‐dimethyl‐benzaldehyde and ethyl hexadecanoate than those in the fermentation of globulin and glutelin; albumin is with higher level of higher alcohols, but higher alcohols are not good for health because of their acute toxicity and neurotoxic effects. In a further fermentation experiment of addition of prolamin, extra prolamin significantly promoted the formation of aroma volatiles, especially medium and long fatty acid esters and β‐phenylethyl alcohol and its acetate, and the content of β‐phenethyl acetate in sweet rice wine with added prolamin was more than twice that of single sweet rice wine. This study demonstrates that the different rice protein components significantly affect the volatiles generated by microorganism metabolism to impact the flavour of sweet rice wine, and the flavour quality of sweet rice wine can be enhanced by increasing the prolamin content.

Effects of Protein Components on the Chemical Composition and Sensory Properties of Millet Huangjiu (Chinese Millet Wine)

“…However, the effect of protein components on reducing sugar content was found to be non-significant, though these values were still within the same range as concentrations reported in previous studies on traditional millet Huangjiu [ 10 , 12 ]. Similar findings were also reported in rice Huangjiu and sake [ 8 , 9 ].…”

“…Previous research has suggested that the production of bitter peptides in sake is highly dependent on the glutelin content of rice grains [ 8 ], highlighting the significance of protein metabolism in shaping the flavor profile of fermented beverages. The development of bitterness in Huangjiu is thought to arise from an imbalance in protein hydrolysis and peptide hydrolysis, emphasizing the importance of carefully balancing the glutelin contents in raw materials to optimize wine quality [ 4 , 6 , 9 ]. Taken together, these findings suggest that carefully selecting the appropriate protein type and amount during the fermentation process is essential to achieving the desired taste profile in millet Huangjiu.…”

“…Likewise, the levels of 3-methyl-1-butanol and 2-methyl-1-propanol in the Glu groups were significantly higher, with increases of approximately 24.2~60.2% compared to the control group ( Figure 4 ). These higher alcohols are known to contribute fruity, winey, and whisky-like notes to the wine [ 9 ], thereby enhancing the richness of the taste. In contrast, the levels of these alcohols in the Alb-1 and Alb-2 groups did not differ significantly from those in the control group.…”

“…The quality of Huangjiu brewed using different raw materials varies greatly. Limited information is only available on the glutinous rice Huangjiu [ 8 , 9 ], whereas the effects of millet protein components on the volatiles and physicochemical properties of millet Huangjiu have not been thoroughly studied. Accordingly, the addition of exogenous glutelin and albumin was used to modify the protein composition of the brewing raw materials, aiming to examine how different protein components affect the flavor and quality of millet Huangjiu.…”

Microbial Communities and Correlation between Microbiota and Volatile Compounds in Fermentation Starters of Chinese Sweet Rice Wine from Different Regions

“…Chinese sweet rice wine (CSRW) is a traditional beverage consumed in China and prized by consumers for its unique flavor and purported nutritional properties related to its enrichment with oligosaccharides, polypeptides, vitamins, minerals, and amino acids [1]. CSRW is generally brewed with glutinous rice and has a low alcohol content, ranging from 0.5% to 14% (v/v), with a savory sweet taste that differs from Chinese yellow rice wine, which is brewed with rice or millet and has a higher alcohol content of 14-20% (v/v) [2,3]. In addition, CSRW fermentation also requires the addition of specific fermentation starters, also known as Jiuqu.…”