Study On Quality Process Of Pretreatment-assisted Multiphysics Combined With Drying Carrot Chips

Carrot(Daucus Carota L.)is rich in nutrients such as carotene,vitamin B₁,B₂,B₆,B₁₂and so on.It has the functions of anti-oxidation,vision protection,anti-cancer and anti-cancer.There are many ways to eat carrots,including steaming,boiling,frying,and making leisure food.At present,carrot leisure chips are mainly fried,but high oil content is not good for health.In recent years,freeze-drying,explosion-puffing drying and other fruit and vegetable products are favored because of their green nature,excellent quality and crisp taste.By means of pre-treatment assisted combined drying,the disadvantages of single drying can be avoided,such as high energy consumption,long time consuming,poor uniformity,etc.,and the comprehensive quality of products can be improved,with a broad application prospect.In this research,carrot was used as raw material,five drying methods were used,such as AD-EPD?MD-EPD?VMD-EPD?AD+MD-EPD and AD-MD-EPD.Through the quality analysis of nutrition and texture,the better combined drying method was selected;based on the optimized combined drying method,supplemented by 10pretreatment methods,the water transfer characteristics are analyzed,the impact of different pretreatment methods on the quality and drying uniformity of carrot chips is explored,the evaluation model is established,and the better pretreatment methods are selected;finally,the pretreatment of carrot chips is coordinated.The combined drying process was optimized to develop healthy and high-quality carrot chips and enhance the added value of carrots.The main results are as follows:1.A comparative study of AD-EPD?MD-EPD?VMD-EPD?AD+MD-EPD and AD-MD-EPD.Effects of five different combined drying methods on the nutrition and texture of carrot chips.The results showed that the highest score was VMD-EPD,and the second was AD+MD-EPD.Compared with the two methods,the pores of carrot chips dried by VMD-EPD were more fluffy,the structure distribution was more uniform,and the drying time was shorter.2.A comparative study of 10 pretreatment methods for the quality and drying of carrot chips was carried out:normal temperature penetration,normal temperature ultrasonic assisted penetration,high temperature penetration+normal temperature ultrasonic assisted penetration,high temperature ultrasonic assisted penetration+freeze-thaw,high temperature penetration+freeze-thaw,high temperature penetration+normal temperature ultrasonic+freeze-thaw,high temperature ultrasonic assisted penetration+freeze-thaw.The results show that the values of A₂₂,S₂₂and T₂₂were the lowest,and the amount of water that was not easy to flow was the most.Through correlation analysis and principal component analysis,the different pretreatment assisted VMD-EPD dried carrot chips were calculated.The highest score was high-temperature penetration,followed by high-temperature ultrasound-assisted penetration+freeze-thaw;the microstructure showed that the pores of the samples after high-temperature ultrasound-assisted penetration+freeze-thaw pretreatment drying were more fluffy,and the taste was better.Therefore,high temperature ultrasonic assisted infiltration+freeze-thaw is the best pretreatment method.3.According to the experimental results of the first two chapters,the technology of ultrasonic assisted infiltration+freeze-thaw pretreatment assisted VMD-EPD was optimized.The effects of different ultrasonic power,ultrasonic time,ultrasonic temperature,osmotic solution concentration,microwave power intensity,water conversion point on the embrittlement,color difference,water and color uniformity,total carotenoid retention and other factors of carrot were analyzed The results showed that ultrasonic power 0.5 W/cm²,ultrasonic time 30 min,ultrasonic temperature 70?,sucrose concentration 30%(w/w),VMD power intensity is 5 W/g dry to 80%moisture content,the expansion temperature is 100?,the evacuation temperature is 75?,the evacuation time is 180-200 min,the stagnation time is 10min,and the moisture content is less than 6%.The results showed that the uniformity of carrot chips was good,the shrinkage and crispness were moderate,the?E was small,and the retention rate of nutrients was good.