Study On The Effect Of Processing Technology On The Quality And Flavor Of Northern-tofu

In this research the yield,moisture content,water retention,as indicator to compared the effect of different 3 kinds of soymilk preparation methods on the quality characteristics of north-tofu,including cooking slurry,uncooked slurry and hot water mixed slurry.The result showed the best soymilk preparation methods.Then research effect of grinding paste liquid ratio,setting temperature,the addition ratio of MgCl2,coagulation time on the quality characteristics of north-tofu and relevance of between quality and texture characteristics.Second,using headspace solid phase microextraction gas Mass spectrometry for qualitative and quantitative analysis of volatile components of different processing conditions of north-tofu with internal standard method,analysis of different processing conditions,the change trend of tofu type and content of volatile flavor substances.Finally,by describing the flavor of volatile substances are classified,present,grass flavor taste,taste and flavor of mushroom oil rancidity bad smell into the beany flavor substances,showing its fragrance,citrus,vegetables,fruit flavor and aroma of caramel smell into non beany flavor substances,the process conditions of different processing under the trend of beany bean curd material and non beany flavor substances,determined to increase the tofu aroma components,reduce the optimum conditions of north-tofu adverse gas compositions,and the beany flavor substances and non beany flavor material content and correlation analysis of all kinds of flavor substances,provide the basis for the regulation of flavor substance in north-tofu.(1)Through the single factor experiment,to study the effect of processing technology on the quality of north-tofu characteristic,determination of cooked slurry prepared north-tofu yield,water retention is best;On the basis of cooked paste method,when material-to-liquid ratio 1:7 g/mL,coagulation temperature is 80?,addition of MgCl2 was 16 mL,coagulation time is 20 min,north-tofu yield,water retention was better.The results showed that the factors such as pulping methods,coagulation temperature,addition of MgCl2 solution and coagulation time had a significant effect on the yield and water retention of north-tofu.(2)According to the correlation analysis between the correlation quality characteristics: diff-erent processing conditions,the hardness,cohesiveness and resilience are negative correlation with the yield,water retention of north-tofu;chewiness and gumminess and resilience and yield,water retention of north-tofu was positively correlated.(3)The qualitative and quantitative analysis of volatile components in north-tofu with differentprocessing conditions was carried out by HSPM-GCMS combined with internal standard method,and through the principal component analysis for analysis of volatile substances and conditions: cooked in slurry method,grinding slurry liquid ratio 1:6 g/m L,solidification temperature of 100?,boiling power of 1400 W and MgCl2 as coagulant,coagulation time was 20 min,the total contents of flavor substances were the highest with;abrasive slurry liquid ratio,solidification temperature,boiling power,solidification time increased,volatile flavor composition of north-tofu difference decreases,found that the influence of several factors on the tofu volatile flavor substances significantly;pulping,coagulant type and volatile flavor composition of bean curd,big difference.(4)Based on the classification of volatile flavor compounds in north-tofu,the effects of processing technology on the components of bean flavor and non bean flavor were studied: cooked slurry prepared is good for keeping the aroma components of north-tofu and reducing the bad gas;On the basis of cooked paste method,material-to-liquid ratio is 1:6 g/m L,cooking power is 800 w,the coagulation temperature is 80?,the coagulation time of 15 min,MgCl2 as coagulant were beneficial to reduce the bean smell matter content,increase the bean smell matter content;So you can according to different needs to change the process conditions to obtain different flavor of the bean curd,improve the acceptable degree.The results showed that the volatile flavor compounds were significantly affected by the.pulping methods,material-to-liquid ratio and coagulation temperature.(5)According to the correlation between the volatile flavor analysis shows that: under different processing conditions,alcohols content were positively correlated with the beany flavor,esters content and material beany flavor was negatively correlated;in addition to grinding slurry liquid ratio,alcohols,aldehydes were also positively with non beany flavor substances,esters in addition to the solidification temperature,other processing conditions and non beany flavor substances were positively correlated.