Study And Application Of Prolamin From Distiller's Grains Of Baijiu

Distiller's grains are the largest by-product in the production process of Chinese liquor,and rich in nutrients,especially protein.They are potential protein resources in industrial application,and if used properly,the added value of distiller's grains can be greatly improved.At present,a large number of studies have been carried out on the development and reuse of distiller's grains,including the development of feed,biogas,fertilizers,white carbon black,and the extractin and separation of phytic acid,melanoidins,and peptides from distiller's grains.However,the extraction and application of prolamin have not been systematically understood and studied in depth.Therefore,this project took distiller's grains of baijiu as the research object,remved the rice husks first,and then obtained “free-rice husk dried distiller's grains powder”(referred to “DDGP”).The basic nutritional components and protein components of DDGP were analyzed.On this basis,prolamin of distiller's grains was extracted before and after drying,and the yield and purity,amino acid composition,and fourier infrared spectrometer(FTIR)and differential scanning calorimetry(DSC)were compared to study whether the drying process the effect on the prolamin extraction of distiller's grains.And then the prolamin was developed and applied.The coating film preservation of bayberry was used to verify the fresh-keeping performance of prolamin extracted from distiller's grains,and finally confirmed the development potential of prolamin from distiller's grains in the application of fresh-keeping of fruit coatings,which opened a new way for the research of reuse in distiller's grains.Thereby increasing the added value of distiller's grains.The main research contents are as follows:(1)Rice husks were removed from the distiller's grains to obtain DDGP with different flavors,and the basic nutritional components and protein distribution of DDGP were measured.The basic nutritional components include crude protein,crude fiber,crude starch,crude fat,crude ash,nitrogen-free extract and moisture.Among them,the nutritional content of the three flavored DDGP is not much different.Compared with distiller's grains with rice husks,the content of crude protein and crude fiber of DDGP changed greatly.The crude protein content increased by about 150 g?kg-1 and the crude fiber content decreased by about 200 g?kg-1.Therefore the rice husks facilitated the subsequent research on distiller's grain protein.Osborne classification was performed on distiller's grains to determine the distribution of protein components of distiller's grains.The protein distribution of the three flavored DDGP was similar,with the highest proportion of prolamin,accounting for 44% of the total extracted protein.Albumin and gluten are next,accounting for about 29% and 23%,with the lowest distribution of globulin,4%.(2)The alcohol-alkaline method and the acetic acid method were used to extract the prolamin from the distiller's grains before and after drying.The alcohol-alkaline method has higher extraction yield and purity of the prolamin,and the amino acid composition,basic structure and thermal properties are not affected by drying,The acetic acid method has a significantly higher extraction yield of fresh distiller's grains than DDGP,and the prolamin of distiller's grains before and after drying,although the structural difference was not obvious,but there are differences in amino acid composition and thermal properties.Finally,it was determined that the alcohol-alkaline method is more suitable for the extraction of prolamin in distiller's grains,and can maintain the consistency of the quality of prolamin in DDGP and fresh distiller's grains,so as to facilitate the subsequent research on the reuse of distiller's grains and gliadin..(3)Prolamin extracted from distiller's grains was used as the coating film substrate for the first time,and glycerol,lactic acid,and polyethylene glycol-400(PEG-400)were used as coating additives.The effect of prolamin on the storage and preservation of bayberry at room temperature was analyzed.The weight loss rate,bad fruit rate,respiration strength,reducing sugar,Vc content,titratable acid,soluble solids,anthocyanins,and malondialdehyde(MDA)content of myrica rubra with and without film during storage were analyzed Variety.The results showed that bayberry preserved with the prolamin film preservative under normal temperature conditions significantly reduced the fruit spoilage rate,weight loss rate,respiration intensity,and MDA content,and the reducing sugar content was maintained at a certain level,compared with the blank control group.The reduction of Vc,titratable acid,soluble solids and anthocyanin content has slowed down,thus delaying the aging process of bayberry and extending the fresh-keeping period by about 2 to 4 days.And then confirming the development and application potential of distiller's grains in the application of fruit coating film preservation,and providing the possibility of improving the added value of distiller's grains.