To Produce Chinese Yam Leisure Food By Explosion Puffing At Variable Temperature And Pressure Difference

In this paper, Lichuan Chinese yam as raw material, using explosion puffing at variable temperature and pressure difference to produce new snack food were studied, determining the terms of the pretreatment of the raw material, extruding technology conditions and product quality evaluation methods, and predicting the shelf life of products. This article also to extract the Lichuan Chinese yam starch and its properties were studied, the research of the specific conclusions are as follows:1Yam crisp slice of variable temperature differential pressure extruding technology and conditionsYam washâ†'slice(2mm thick sheet)â†'color save(0.12%VC,0.5%citric acid,0.03%sodium sulfite)â†'pre-drying(60℃drying to25%moisture content)â†'the variable temperature differential expansion (puffing temperature is105℃,pressure differential is0.15-0.2MPa,stagnation period is10min,evacuated time is1h,temperature60℃and55℃)â†'seasoning (3%vegetable oil,8%seasoner) thermal drying (the condition of80℃drying10min)â†'packaging2Yam flavored chips expected shelf life is150days, the original chip shelf life for500days.3Yam crisp slice quality evaluation methodsTo taste (out of30points), integrity (out of10points), smell (out of10points) for the sensory quality evaluation, combined with anti-stiffness index, whiteness, the product moisture content on the puffed product quality evaluation4Effect of extrusion process on the quality of the productWater content, puffing temperature has a significant influence on the expansion ratio, pulverizing resistance ratio, product moisture. The interaction effect of water content and vacuum time has a influence on the pulverizing resistance rate. The interaction effect of water content and puffing temperature has a significant influence on product moisture.5extraction process and properties of Lichuan Chinese yam starch(1)Process conditionsDried Chinese yam starchâ†'crushingâ†'sievingâ†'adding water (the ratio of solid to liquid1:10)â†'adjusted to pH10â†'ultrasonic treatment (20min)â†'filteringâ†'examination of iodine liquidâ†'centrifugingâ†'drying(2) Transparency:potato starch> Lichuan yam starch>corn starch> sweet potato starch. Freezing and thawing:sweet potato starch> potato starch>corn starch> Lichuan yam starch. Gel strength:corn starch> Lichuan yam starch> sweet potato> potato starch.Anti aging:sweet potato starch>corn starch>potato starch>Lichuan yam starch.Thermal stability:sweet potato starch>corn starch> Lichuan yam starch> potato starch.The pasting start time was advanced by the pH. The pasting temp was improved in the salt solution. The curve of pasting properties was reduced in the amylase solution. The stability of starch paste in high temp and anti-aging ability were weakened in the sucrose solution. The peak viscosity of starch paste was reduced in AgNO3solution.