| Fresh waxy corn has rich nutrition and excellent taste,and its processed products can effectively extend the marketing period of waxy corn,so as to meet the needs of consumers.Jiangsu Province is rich in waxy corn variety resources,but the quality is not uniform,so it is difficult to screen and promote suitable varieties for processing.Therefore,in this paper,17 waxy corn varieties planted in Jiangsu Province were selected as the research objects,and the quality evaluation indexes of cooked waxy corn and instant waxy corn were analyzed by principal component analysis and correlation analysis,so as to establish the quality evaluation models of cooked waxy corn and instant waxy corn,This study provides a theoretical basis for the selection of Waxy Corn Varieties in Jiangsu Province.The main research contents and results are as follows:1.Quality analysis of different varieties of fresh glutinous cornThe appearance of fresh ear and nutritional composition of grain of 17 varieties of waxy corn were determined.The results showed that the appearance quality of fresh samples differed in different degrees,and Suyunuo 5 is the smallest in length,Wannuo 2000 has the widest rod.Among the basic nutrients,the water content of 17 kinds of waxy corn grains ranged from 53% to 67%,amylopectin content accounted for more than 95% of the total starch,and dietary fiber content was 14.82-20.01 g/100 g,among which the insoluble dietary fiber accounted for a large proportion,and the contents of crude protein and crude fat were not significantly different,but the total sugar content of sweet waxy corn was significantly higher than that of waxy corn.Fructose,glucose and sucrose were detected in17 kinds of fresh waxy corn samples,among which sucrose content was the highest,glucose content was the second,and fructose content was the lowest.A total of 18 kinds of free amino acids were detected,and 9 varieties with a total amount of more than 30 mg/g were detected,the highest content was Asp or Ala.The variation coefficient of each amino acid content was more than 100%,and the content of each amino acid was significantly different.2.Study on quality evaluation of cooking waxy cornThe quality indexes of cooked waxy corn were measured and analyzed statistically.The results showed that the fresh waxy corn after cooking had the obvious flavor of corn ripening,but the nutrient composition would be partially lost.Principal component analysis and correlation analysis were used to extract the core indexes that had greater influence on quality,and there were 8 indexes including amylopectin,soluble dietary fiber,fructose,2-ethylhexanol,dimethyl sulfide,sucrose,hexanal and Ala,among which dimethyl sulfide had the highest weight coefficient.The evaluation model for cooking waxy corn was as follows: Z=0.0761 × amylopectin + 0.1008 × soluble dietary fiber + 0.1139 × fructose +0.1152 × sucrose + 0.1727 × Ala + 0.2170 × dimethyl thioether + 0.0841 × hexanal +0.1202 × 2-ethyl ethanol.According to the result of sensory evaluation,the quality of waxy corn was graded,17 varieties of waxy corn reached the level of 2 or above.In the validation of the evaluation model,the rank correlation coefficient test between the grey correlation degree of cooked waxy corn quality and sensory evaluation grade reached extremely significant correlation.Accordingly,Sukenuo 9,Sukenuo 11,Sukenuo 1505,Sukenuo 1701,Sukenuo 1702 and Wannuo 2000 were selected as the suitable varieties for cooking and processing.3.Study on quality evaluation of instant processed waxy cornThe product quality standard system was established by analyzing the quality of samples of 17 waxy maize varieties after instant processing,and the mathematical q uality evaluation results were verified by comparing them with the sensory evaluatio n results.The results showed that fructose,soluble dietary fiber,dimethyl sulfide,C ys,amylopectin,furaldehyde,Gly,maltose,Ala and crude protein were selected as t he core evaluation indexes of the comprehensive quality of waxy corn through the a nalysis of principal component and correlation.The index weights of amylopectin,s oluble dietary fiber,fructose,crude protein,maltose,Gly,Ala,Cys,dimethylthioethe r and furaldehyde were calculated by entropy weight method,which were 0.0555,0.1156,0.1099,0.1069,0.0529,0.1444,0.0764,0.1579,0.0798 and 0.1005,respectivel y.The evaluation model of instant waxy corn was as follows: Z=0.0555×amylopecti n +0.1156×soluble dietary fiber + 0.1099 × fructose + 0.1069 × crude protein +0.0529 × maltose + 0.1444 × high Gly + 0.0764 × high Ala + 0.1579 × high Cys + 0.0798 × dimethyl thioether + 0.1005 × furaldehyde.In sensory evaluation,Wannuo 2000 had the highest score,followed by Sukehuanuo 2008,Sukenuo 1702 and Suken uo 1501,all of which reached the first-level standard.In the validation of the evalu ation model,the rank correlation coefficient test between the grey correlation degree of instant waxy corn quality and sensory evaluation grade reached extremely signifi cant correlation.Therefore,Wannuo 2000,Sukehuanuo 2008,Sukenuo 1702 and Suke nuo 1501 were selected as suitable varieties for instant processing. |
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