Research On The Preparation Methods And Materials Optimization And Quality Effects Of Extrusion And Fermentation For Chazi

Chazi is a traditional fermented food of corn, because of its unique flavor, rich innutrition, slightly acidic taste has been loved by the people. However, the probloms ofthe traditional method of producing Chazi are the long production period and short shelflife. But in recent years, the fermented food of corn has bright market prospects, inorder to extense the traditional food.This paper describes the relationship betweenextrusion and fermentation of corn flour, and the effects of fermentation and rawmaterial composition on the quality of Chazi are studied too.The mainly experimentconclusion as follows:(1) Extrusion and expansion make specific surface area of corn meal increase178%, the pore size ranges from2.89~17.93mm to3.42~20.47mm，impel the samplesdirect to pore size rising trend; at the same time it can reduce time of expansion, whenferment to pH＜4, expansion corn meal shorten9hours than unexpansion corn meal,the total acid reach to16.00g/kg, expansion corn meal shorten6hours. If the specificsurface area and pore size unferment corn meal bigger, the specific surface area andpore size ferment corn meal bigger, the effect of fermentation is more obvious.(2) Appropriate fermentation time to improve the cooking quality of extrudedChazi, it takes90s to fermented is the best for various index, the time of cooking is390s,the water absorption of dry matter is48.57%, the loss rate of dry matter is7.25%, themature broken strip rate is9.5%. Fermentation improve texture characteristics of Chazi,with fermentation time increasing the index of TPA experiment smaller increases afterthe first, Hardness, gumminess, chewiness changed significantly, when samplefermented to12h becomes maximum, it is4916.42g,4421.95and4550.71. Whenfemented time increase, shearing stress and tensile stress have similar trend, reach themaximum175.92g and17.12g. Fermentation can improve colour, apparent state,palatability, resilience and smoothness of Chazi.(3) Fermented expansion corn meal combine with fermented corn meal, bindingextrusion technology to produce Chazi. By response surface optimization correction, wecan achieve optimal plan. Fermented corn meal particle size of60mesh, expansion cornmeal fermented particle size of80mesh,62%of the water addition, fermentedexpansion corn meal ratio of22%, the ratio of fermented corn meal78%, watertemperature is36℃. The cooking time of Chazi is short, the rate of loss of dry matter is small and the quality of Chazi is good. Due to the method of extrusion processing, thestorage time of Chazi longer and the drawbacks of the traditional production process areovercome.