Isolation and identification of the bitter compound from Huangjiu

Zhong

et al. 2022

Int J of Food Sci Tech

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.

Section: Resultsmentioning

confidence: 99%

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

Zhong

et al. 2022

Int J of Food Sci Tech

“…The S. rosea A22 screened in this study was mainly used for the production of inoculated raw wheat qu, while the most commonly used microorganism in huangjiu inoculated with raw wheat qu is Aspergillus flavus (A. flavus) SU-16 (GCA_009856665.1) (Liu et al, 2020). However, due to the addition of cooked wheat qu inoculated with SU-16, the huangjiu exhibited a bitter and astringent taste, which seriously affected the drinking comfort of huangjiu (Lu et al, 2021). Therefore, there is an urgent need for a Frontiers in Microbiology frontiersin.org new wheat qu to replace the traditionally cooked wheat qu.…”

Section: Stress Resistance Analysis Of Saccharopolyspora Rosea A22mentioning

confidence: 99%

Complete genome sequence, metabolic model construction, and huangjiu application of Saccharopolyspora rosea A22, a thermophilic, high amylase and glucoamylase actinomycetes

Liu²,

Han³

et al. 2022

Front. Microbiol.

Saccharopolyspora is an important microorganism in the fermentation process of wheat qu and huangjiu, yet the mechanisms by which it performs specific functions in huangjiu remain unclear. A strain with high amylase and glucoamylase activities was isolated from wheat qu and identified as Saccharopolyspora rosea (S. rosea) A22. We initially reported the whole genome sequence of S. rosea A22, which comprised a circular chromosome 6,562,638 bp in size with a GC content of 71.71%, and 6,118 protein-coding genes. A functional genomic analysis highlighted regulatory genes involved in adaptive mechanisms to harsh conditions, and in vitro experiments revealed that the growth of S. rosea A22 could be regulated in response to the stress condition. Based on whole-genome sequencing, the first genome-scale metabolic model of S. rosea A22 named iSR1310 was constructed to predict the growth ability on different media with 91% accuracy. Finally, S. rosea A22 was applied to huangjiu fermentation by inoculating raw wheat qu, and the results showed that the total higher alcohol content was reduced by 12.64% compared with the control group. This study has elucidated the tolerance mechanisms and enzyme-producing properties of S. rosea A22 at the genetic level, providing new insights into its application to huangjiu.

“…The content of bitter amino acids in Shaoxing Huangjiu has been found to be positively correlated with temperature and closely related to mold starters . Recently, the bitter compound pyroglutamate peptide was identified in Shaoxing Huangjiu for the first time, and its content was found to be affected by the type of wheat Qu . Other studies have found that the soaking time of and albumin content in glutinous rice affect bitterness and astringency .…”

Section: Introductionmentioning

confidence: 99%

“…5 Recently, the bitter compound pyroglutamate peptide was identified in Shaoxing Huangjiu for the first time, and its content was found to be affected by the type of wheat Qu. 21 Other studies have found that the soaking time of and albumin content in glutinous rice affect bitterness and astringency. 4 Therefore, the bitter compounds considered characteristic to Shaoxing Huangjiu should be investigated to better understand their ideal profile.…”

Section: ■ Introductionmentioning

confidence: 99%

Characterization of Bitter Compounds in Shaoxing Huangjiu by Quantitative Measurements, Taste Recombination, and Omission Experiments

Xie

et al. 2022

J. Agric. Food Chem.

Excessive and uncoordinated bitterness of Shaoxing Huangjiu, a traditional Chinese rice wine, reduces its acceptance by consumers. To determine the compounds responsible for this bitterness, gas chromatography−mass spectrometry and highperformance liquid chromatography were performed on four types of Shaoxing Huangjiu (Yuanhong, Huadiao, Shanniang, and Xiangxue wine) for targeted quantitation of candidate compounds known to contribute to bitterness. Calculations of dose-overthreshold factors revealed that isoamyl alcohol, 1-hexanol, phenylethanol, ethyl butyrate, ethyl lactate, furfural, histidine, and arginine were important bitter compounds. Taste recombination experiments demonstrated that a recombination model constructed using the screened known bitter compounds showed good similarity with the original sample in bitter taste. Furthermore, omission experiments revealed that isobutanol, isoamyl alcohol, 1-hexanol, phenylethanol, ethyl acetate, ethyl butyrate, ethyl lactate, furfural, arginine, and valine were the compounds affecting the bitter taste perception. This study provides a certain guiding effect on the bitterness control and taste improvement of Shaoxing Huangjiu.