Study On The Effect Of Heat Sterilization On The Quality Of Canned Citrus Fruits

Citrus fruit is the highest yield of our country,and most of the citrus can be processed into canned citrus,accounting for more than 80%of citrus processing capacity.Thermal sterilization is the most important way of sterilization of canned food,through the heat sterilization can kill microorganisms in food,to ensure the safety of food.But also affect the color and flavor of the food.In this paper,through the variation of the temperature in the tank was studied under the condition of different thermal sterilization,combined with temperature variation analysis of the effect of different sterilization conditions of canned citrus nutrients,through sensory evaluation and electronic noses,electronic tongue instrument to evaluate under the conditions of different sterilization of canned citrus quality.Used distributed temperature sensor under different conditions sterilization tank temperature measxxrement,the data collected to be processed,compared to under different conditions inside the tank temperature.Near the wall of the tank,the temperature was rising faster than the center point,the sterilization temperature was 80 degrees Celsius,the rotation can make the center point to reach the sterilization temperature of 40%,the horizontal rotation can be reduced by 8%of the time.The results showed that the temperature of the position near the wall of the tank rises rapidly,and the temperature of the center point of the wall was increased slowly.The higher the temperature,the faster the temperature difference was.Rotation was conducive to heat transfer,can shorten the center point to reach the time of sterilization temperature.The smaller rotation sped can also shorten the sterilization time of the canned food.The horizontal rotating effect was better than vertical rotation,horizontal rotation was more conducive to heat transfer.Study on the changes of nutrients in the canned citrus treated with different sterilization conditions.The sterilization time is 30min,the sterilization temperature is 80 C,85 C,90 C,the impact on the Vc maximum,Vc loss of 27%;Sterilization temperature of 95 degrees,100 degrees Celsius on the impact of the largest total sugar,loss of 37%;The reducing sugar content of 10min before sterilization decreased after 100in began to rise,The reducing sugar content increased by 32%.Results showed that sterilization temperature and time,heat accumulation tank,heat accumulation of more Vc,carotenoids,flavonoids,total acid,total sugar and other nutrients influence bigger,more serious loss.The hydrolysis rate of total sugar was higher than that of reducing sugar,and the content of reducing sugar increased.Used artificial sensory evaluation and electronic nose and tongue quality assessment on the sterilization of canned citrus in different conditions.The longer the sterilization temperature,the longer the time,the impact on the taste and flavor of the Canned mandarin oranges.The principal component analysis can be divided into 4 types of citrus can be divided into categories,the difference is significant.Results showed that low temperature and short time sterilization of canned citrus quality and aroma components damage.Sensory evaluation results and the use of electronic nose and tongue was consistent,that electronic tongue and nose can be used for sensory evaluation of canned citrus.