Effect Of Storage Temperature And Heat Treatment On Storage Quality Of Fresh-cut Pitaya

Pitaya,also known as red dragon fruit,is a new kind of tropical fruit,and has certain health care function.With the marketization of fresh-cut fruits and vegetables,fresh-cut pitaya is favored by consumers because of its convenience,hygienic,fresh,nutritional and some other advantages,preservation technology of fresh-cut pitaya arises at the historic moment.Thus,in this paper,red pitaya is used as the test material to study the influence on nutritional quality,physiological biochemistry and microbiological aspects of fresh-cut pitaya with different storage temperature and hot air treatment,in order to provide a scientific basis and theoretical guidance on machining,retaining freshness and extending storage duration of fresh-cut pitaya,the main results are as follows:(1)Different storage temperature(0、4、10 and 20 ℃)have a significanteffect on sensory organs,nutritional quality,active oxygen metabolism,antioxidant enzyme activity and microbiological aspects of fresh-cut pitaya.Compared with other temperature,lower temperature(0 and 4 ℃)can make fresh-cut pitaya maintain better sensory quality,significantly reduce the weight loss rate,delay the descent velocityof hardness,TA,TSS,Vc and soluble protein content of fresh-cut pitaya,steady the content of anthocyanin;Also,lower temperature(0 and 4℃)can inhibit the generation rate of O2-,the content rise of H2O2 and MDA,delay the activity peak of antioxidant enzymes such as SOD and CAT,maintain high activity,ease the damage of active oxygen(ROS)free radicals to fresh-cut pitaya after 10 days’storage,so the aging process was delayed;After 10 days’storage at low temperature(0 and 4℃),fresh-cut pitaya can still maintain a lower total number of colonies,mold and yeast count,thereby to extend the storage duration.But,in the end of the storage at 0℃ may be due to low temperature damage,the fruit color was dimmer than the storage at 4 ℃,considering the cost and the requirement on control fridge temperature,4℃ can be selected.(2).Hot air treatment(40℃15min、50℃15minand 60℃15min)has certain effect on storage quality,active oxygen metabolism,and microbiological aspects of fresh-cut pitaya,thereinto,50℃ 15 minhot air treatment can significantly reduce the weight loss rate of fresh-cut Pitaya,slow down its hardness,and do no significant effect on color;50℃ 15 min hot air treatment also can maintain high content of TA,TSS,Vc during storage,play a certain inhibitory effect on reproduction of microorganisms and inhibit the generation rate of O2·-,the content rise of H2O2 and MDA,effectively slow down the damage of active oxygen(ROS)free radicals and the occurrence of membrane peroxidation to fresh-cut pitaya,thereby to delay the senescence of fresh-cut pitaya and maintain good storage quality.