| Strawberry are a common and important fruit because of higher nutrition and better taste.Strawberry is highly perishable and susceptible to deterioration after harvest,which leading to a very short shelf life and high postharvest loss.Fungal infections play a major role in losses of strawberry during postharvest processing,transportation,retail and storage.Therefore,controlling strawberry postharvest disease is important for strawberry storage.This thesis toke "Hong yan" strawberry as the research material,to determine the optimum picking strawberry maturity and harvesting period by studying the influence of the strawberry maturity stage and different harvest time on quality changes;the effect of volatiles released from Hanseniaspora uvarum and modified atmosphere packing treatment(MAP)on strawberry storage performance,which provide theroetical basis and technical guidance to improve quality and prolong shelf life of strawberry.The main research contents and results are as follows:1.Characteristics of mature quality of strawberry and quality changes of strawberry at different harvest periodThe experiment was carried out on "Hong yan" strawberry fruit.Firstly,the mature quality properties of different maturities strawberry fruits were studied.The result showed that,during the maturation,the appearance quality was improved,strawberry flesh gradually softened,among them,the hardness?chewiness and elasticity decreased from ginkgo to the 1/2 fruit stage,and changed slower at late maturation.The content of total soluble solids in the whole red strawberry fruit was the highest,up to the 7.9%and the lowest acid was the lowest about 4.0%.The main aroma components of strawberry was organic acid and with the increase of maturity the easter compounds gradually increased.Secondly,the change of quality properties of different harvest time was studied,which were harvested on March 31st,April 12th and April 20th,due to before April 12th,the quality characteristics of the strawberry because of the different weather temperature,humidity and light intensity of the strawberry fruit were also changed.The light intensity is not favorable for strawberry coloration,and the low temperature is beneficial to the accumulation of total soluble solids.2.The effect of Hanseniaspora uvarum biofumigation on postharvest quality of strawberryStrawberry fruits were sealed in the dryer which contained several culture mediums with yeasts in the bottom.The results showed that commodity rate of group treated with volatile organic compounds of yeasts was 98%,while that of control group was 32%.And biofumigation treatment could decrease the weight loss rate,keep strawberry appearance better and hardness,delay increase the pH value and maintain more volatile compounds.It is deduced that volatile organic compounds from Hanseniaspora uvarum can improve the storage performance of strawberry.3.Effects of cold storage and MAP treatment on storage quality of strawberryThe experiment was carried out on the eight maturity "Hong yan" strawberry fruit,conducting(5±0.5)%O2+(5±0.5)%CO2 MAP and cold treatments in 1.0?4.0? RH 90-95%cold storage for 28 days.The results showed that compared with the control,MAP treatment and cool storage could better maintain the appearance of strawberry,reduce the deterioration,keep the fruit color,delay the hardness,chewiness,elasticity and other texture and total soluble solids decline.And the effect of MAP treatment was better than cool storage.Therefore,MAP treatment has a positive effect on postharvest storage quality of strawberry. |
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