| The brewing technique of Shanxi mature aged vinegar had already been included in the national intangible cultural heritage,thus it was significant to inherit and carry forward the vinegar brewing technology.Old vinegar production mainly contained saccharification,alcohol fermentation,acetic fermentation processes and so on.Starch saccharification was primary part of the old vinegar production,its success or failure had a great influence on the subsequent brewing process,and whose important prerequisite were starch gelatinization and liquefaction,therefore,the gelatinization properties of sorghum were researched clearly in the process of the old mature vinegar brewing,this could be prepared for saccharification.This paper analyzed the starch contents,protein contents,enzyme activity of sorghum,bran and daqu,which were belonged to the pasting raw materials of the old mature vinegar,and explored the gelatinization properties of sorghum in the old mature vinegar production,in order to provide certain reference and theoretical basis for the process of old mature vinegar sorghum gelatinization and provide possobility for saving the production cost and improving the economic benefit in the actual vinegar production process.The research contents and results of the paper were as follows:First,hydrochloric acid hydrolysis method was used to measure the starch contents of sorghum,bran and daqu,Kjeldahl method was usde to determine the protein contents of sorghum,bran and yeast,Fehling reagent way was used to calibrate the saccharifying enzyme activity of bran,daqu and commercial enzyme,and folin-phend method was used to evaluate the pro-tease activity of bran and daqu.Besides,the degree of soaking raw materials of two kinds of crushing degree of sorghum in different immersion time were studied,which refereed to the steep-out moisture determination means of barley.The results of this study were:sorghum,bran koji and yeast starch contents were in turn 63±0.56g/100g,41.35 ± 1.2g/100g,51.76 ±0.62g/100g;the protein contents of sorghum and daqu in turn were 7.86 ±0.72g/100g and 21 ± 1.05g/100g;saccharifying enzyme activity of bran,yeast and commercial enzyme were in order 2700 ± 66u/g,960 ± 36u/g and 73600 ± 129u/g;the enzyme activity of bran neutral protease,acidic protease and daqu acid protease in order were 832 ± 25u/g,639 ± 16u/g and 396 ± 9u/g.The results of sorghum leaching concentration indicated that:considering two aspects of the soaking effect and economic benefit,the best soaking time of complete sorghum grains was selected 40min,the best time of 16 mesh sifter sorghum was dipped for 20min.The experiment analyzed the sorghum gelatinization characteristics in the old mature vinegar production,first of all,according to national standards and literature introduction to vinegar brewing process,the gelatinization process of sorghum was identified and the method to research gelatinized sorghum degree was established.Secondly,in order to study the tendency and the regularity of gelatinization degree in the whole pasting process,the gelatinization level of the 12 mesh screen sorghum was determined,and then the correlation between pasting degree and liquefaction degree of 16 mesh sieve sorghum was studied in the experiment,at last,the influence factors of paste degree were explored,mainly including two sides of elements:one aspect was the comparison of starch paste level size and change trend of three kinds of grinding extent of sorghum,which were 60 mesh sieve,20 mesh and 12 mesh sieve,the second was the comparison of gelatinization starch level size and change trend of five kinds of dipping raw materials time,which were Omin,20min,40min,60min,80min respectively.The outcomes of this subject were as below:(1)The two determination conditions of gelatinization degree were determined:the determination of the total paste time was determined to be 20min,saccharifying enzyme amount was determined to be 4%.Thus,the suitable analysis method was determined for the sorghum gelatinization degree determination.(2)12 mesh screen sorghum confirmed the pasting requirement by gelatinizating 57 minutes.(3)The pasting level change tendency of 16 mesh sifter materials were the same as its liquefaction level,the latter degree increased with the increase of the former degree,which showed that there was a positive correlation between the crude materials gelatinization level and the liquefaction extent.(4)The affecting factors of pasting degree results suggested that:sorghum pasting degree size with different crushing degree:60 mesh sieve materials>20 mesh sieve materials>12 mesh sieve materials,which revealed that under the same conditions,the different grinding particle size had an impact on the sorghum paste degree,the more greater crushing degree,the more greater pasting extent;Under the same conditions,when the run time was in 20-40min,the paste degree could be reached the best,and then with the extension of the run time,there was no effect on the sorghum gelatinization degree. |
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