Effect Of Decoction Process On The Quality And Antioxidant Activity Of Hakka Rice Wine

Fried wine plays an important role in brewing Hakka rice wine,which has a great influence on the rice wine color,flavor substances and its biological activity.However,there are few reports on the effect of rice wine decoction technology on its quality at home and abroad.The paper mainly studied the effects of decoction process on color,basic physical and chemical indicators,aroma components,amino acids,organic acids and antioxidant activities in Hakka rice wine,and analyzed the changes of peptide substances in rice wine before and after decoction by liquid-mass spectrometry.The influence of decoction on the peptide substances in Hakka rice wine was discussed.The main research results were as follows:1.After using electronic nose and electronic tongue to analyze the difference of wine samples under different decocting conditions and the effect of decoction on the color of Hakka rice wine was determined by an ultraviolet spectrophotometer,the results showed that compared with the non-decocted wine sample,the taste,flavor,and color of the fried wine condition in 90 °C and 35 min were greatly changed,Combined with the actual situation of the factory.Therefore,90 °C and 35 min were used as the subject in the study.2.The GC-MS was used to detect the flavor substances before and after decoction.The results showed that 66 volatile flavor substances were identified in the two wine samples before and after decocting.The number of volatile flavor substances in the wine samples before and after decocting was 35 and 49 respectively.There were common 18 flavors before and after decocting,and the total volatile content increased by 8.2 %.3.Through GC-Tof-MS,97 kinds of substances were detected in the two samples before and after decocting,including 48 kinds of acids,14 kinds of alcohols,3 kinds of ketones,2 kinds of lipids,3 kinds of aldehydes,6 kinds of amines,and 21 kinds of sugars.The analysis found that the content of the substance in the sample after decoction would change to various degrees and the wine could be better improved in the sensory quality of the new wine sample.4.The study analyzed the effects of decoction on conventional physical and chemical indicators,amino acids,organic acids,GABA and polypeptide in rice wine.The results showed that after the decocting treatment,the content of the conventional physical and chemical indicators of the wine samples increased with soluble solids and amino acid peptide nitrogen,and the content decreased with pH,total sugar,total phenol,protein and alcohol;The total amount of amino acids increased by 15.7 %;the content of acetic acid changed most obviously,which was 43.74 % lower than that before decoction,while the content of other non-volatile organic acids were increased relatively,compared with pyruvate acid,lactic acid and propionic acid increased by 16.90 %,8.46 %,and 12.84 %,respectively;the content of γ-aminobutyric acid were increased after decocting treatment,and increased by 59.30 % compared with non-decocted rice wine.5.The peptides in Hakka rice wine were detected by LC-MS/MS,and a total of 155 components were detected.Among them,33 kinds of peptides have been detected in the literature,including 28 dipeptides,5 kinds of tripeptides.After decoction treatment,the relative content of peptides in the sample increased by Leu-Arg,Phe-Ile,Arg-Tyr,Thr-Leu,Pro-His-Gln;the content of Phe-Val,Gln-Tyr,Ile-Trp,His-Ala,Gln-Trp,Glu-Phe,Arg-Ser,Ile-Val-Tyr,Ala-Ile-Pro were decreased;the content of several other peptide components did not change significantly.6.The study found the effect of decoction on the antioxidant activity of Hakka rice wine in vitro.The total antioxidant capacity of rice wine was determined by the thiocyanate method.The results showed that the total antioxidant capacity of both samples increased with the increase of dose within a certain dose range.The DPPH free radical scavenging ability of the sample was determined.The results showed that when the sample was added in 1 mL,the clearance rates of the two wine samples before and after decoction were 51.57 % and 60.60 % respectively.The reduction ability of the samples was determined by potassium ferricyanide method and the FRAP method.It was BHT> wine sample after decoction> wine sample before decoction;through the study of metal ion binding ability of rice wine,when the sample addition amount was 2 mL,the metal binding ability of the two samples was 38.22 % and 50.78 %,respectively.The Fenton method was used to determine the scavenging ability of rice wine against hydroxyl radicals.The results showed that when the sample was added in 1 mL,the OH-clearance rates of the two samples before and after decoction were 55.50% and 60.26%,respectively.The study also found that the antioxidant capacity of the samples after decoction was stronger than that of the non-decocted samples,indicating that the decoction had a certain promoting effect on the in vitro antioxidant activity of the yellow wine.