Comparative Study On The Process And Quality Of Soft-packed Sour-coated Bamboo Shoots And Fermented Bamboo Shoots

The bitter bamboo shoots have crisp texture,unique flavor,high nutritional and edible value,but the bitter bamboo shoots have a certain bitter taste,and the quality changes of the bitter bamboo shoots are extremely fast,which limits their consumption and processing.In order to solve these problems,this study takes bitter bamboo shoots as raw material,treats it with acid pickling and fermentation,and optimizes its processing technology through orthogonal experiment to study the quality difference of two soft-packed bitter bamboo products.According to the quality changes at different temperatures,the product shelf life prediction model was established.The specific research contents and results are as following:1.Research on processing technology of sour bitter bamboo shoots.The effects of acid,acid concentration,salt concentration and sugar addition on the processing conditions of acid-coated bamboo shoots were investigated.The sensory scores were used as indicators to determine the optimal conditions for each single factor.On this basis,the three factors with greater influence were optimized and verified by orthogonal test.The best formulation was obtained by mixing citric acid,lactic acid and acetic acid in a ratio of2:1:1,the acid addition amount was 0.6%,the salt addition amount was 2%,and the sugar addition amount was 3%.The effects of sterilization conditions on the quality of soft-packed bitter bamboo shoots were investigated.The total number of colonies and hardness after heat preservation experiments(37?for 10 days)were used as indicators to obtain the best sterilization conditions for sterilization for 20 minutes at 80?.2.Study on the processing technology of fermented bitter bamboo shoots.The effects of inoculum,fermentation temperature,salt concentration and sucrose addition on the sensory quality of bitter bamboo shoots were studied.The orthogonal fermentation experiment showed that the best fermentation process of bitter bamboo shoots was fermentation temperature 30?,salt concentration 6%,sugar addition 2%,inoculated with10~4 CFU/g.3.Comparative analysis of the quality of pickled and fermented bamboo shoots.Sensory evaluation of sucrose and fermented bamboo shoots,chromatic aberration,texture,nutritional indicators,physical and chemical indicators,flavor components and microbial indicators were compared and analyzed.The results showed that the total acid content of sour bamboo shoots was higher than that of fermented bamboo shoots.The main organic acid of fermented bitter bamboo shoots is lactic acid,and the main organic acids of sour bitter bamboo shoots are oxalic acid,citric acid and tartaric acid.The total scores of sensory scores of fermented bitter bamboo shoots and sour bamboo shoots were not much different.The texture characteristics of acid-coated bitter bamboo shoots were better than that of fermented bamboo shoots.The sour bitter bamboo shoots are brighter and yellower than the fermented bitter bamboo shoots,but the fermented bitter bamboo shoots are redder than the sour bitter bamboo shoots.The two kinds of bitter bamboo shoots?E=4.69,the color difference is large,and it is easier to distinguish visually.Acidic bitter bamboo shoots can better maintain the original nutrients of bitter bamboo shoots,and the content of bitter amino acids is reduced to improve the flavor.The volatile flavors of fermented bitter bamboo shoots and acid-coated bitter bamboo shoots are quite different.Fermented bitter bamboo shoots detected 17 kinds of volatile flavor substances such as esters,alkenes,alkanes and aldehydes.Acidic bitter bamboo shoots detected four kinds of volatile flavor substances of esters and alkenes.The microbial indicators of the two flexible packaging products were 0.After the heat preservation experiment,there was no bag leakage phenomenon,and the two products met the commercial sterility requirements.4.Quality changes and shelf life prediction during the storage of two kinds of soft-packed bitter bamboo shoots.When stored at 25?,35?,45?,the hardness of both soft-packed bitter bamboo shoots gradually decreased.The color difference L value decreases,the a value increases,the b value of the fermented bitter bamboo shoots gradually decreases,and the b value of the acid-coated bitter bamboo shoots first increases and then decreases.A shelf life prediction model was established by the chromatic aberration and hardness changes of the two kinds of bitter bamboo shoots during storage,and the shelf life of the two soft-packed bitter bamboo shoots at 25?was predicted.The color difference prediction model predicted that the shelf life of fermented bitter bamboo shoots was 120.21days,and that of sour bitter bamboo shoots was 165.12 days.The hardness prediction model predicts that the shelf life of fermented bitter bamboo shoots is 102.55 days,and that of sour bitter bamboo shoots is 130.53 days.