Effect Of Different Temperature And Film Packaging Treatments On Physiology And Quality Of Hawthorn Fruits During The Storage

Hawthorn is the unique tree of our country, planted in a large acreage, has high output, nutrients content of the fruits is rich, so hawthorn fruit is deeply loved by people. However, due to its unique sour, the fresh eating is limited. Hawthorn’s processing industry has developed rapidly in recent years, more and more increasing demand for hawthorn has put forward higher requirements on its storage and fresh-keeping. Now generally use traditional methods store hawthorn, it is very easily to lose water and poor the fruits’ quality during the storage, fresh keeping technology remains to be further improved.In this research “Da Jinxing” hawthorn fruits were chosen as the test material, mainly studied the effects of different storage temperatures and different film packaging treatments on hawthorn fruits’ physiology and storage quality. According to analysis the results to ascertain better storage temperature and packaging material, In order to extend the storage period of hawthorn, and provide a theoretical basis for the storage of hawthorn in production practice. The main research results are as follows:1. By the study of different temperature（-2℃,-0.5℃and 1℃） on storage quality of hawthorn, the research showed: Compared with the storage conditions of-2℃, 1℃, at the storage temperature of-0.5℃, which significantly postponed the decreasing of fruit firmness, reduced the loss of titratable acid and Vitamin C, and also reduced the weightlessness rate and the rot rate, slowed down the decline of reducing sugar content, thereby inhibited the browning of hawthorn fruits. Stored up to 105 th days, hawthorn’s firmness were 2.67 N and 3.31 N store at 1℃ and 0.5℃, which all extremely significantly different with 1.97 N under-2℃（P<0.01）. At the temperature of-0.5℃ hawthorn fruits’ titratable acid content was significantly higher than 1℃（P<0.05）, and had extremely significant differences with-2℃（P<0.01）; The Vc content of hawthorn was extremely significantly different with 1℃, 2℃（P<0.01）; a* value was 2.27, the content of reducing sugar was 9.69%, the weightlessness rate was 9.69%. At the temperature of- 2℃, the rot rate of hawthorn was 30%.2. By the study of different temperature（-2 ℃,-0.5 ℃ and 1 ℃） on storage physiological indexes of Hawthorn fruits, the studies indicated: At the storage temperatureof-0.5℃could inhibit the respiratory rate of the fruits, delay the breath peak and reduce its peak, and decrease the decline in antioxidant enzyme activity of POD, inhibit the increase of MDA content and activity of PPO. Throughout the course of storage, at the temperature of-0.5℃ fruits’ POD activity maximum was the highest, the difference was notable with that stored under 1℃（P<0.05） and extremely significant with-2℃（P<0.01）; The content of MDA increased more slowly, which had significant difference compared with 1℃（P<0.05） and extremely significant difference with-2℃（P<0.01）. To the 105 th day of storage, The PPO activity of hawthorn fruits stored under-0.5℃ was the lowest,which had notable difference with-2℃（P<0.05） and extremely significant difference with 1℃（P<0.01）.3. Different film packaging treatments（15 μm PE film, 15 μm PE microporous film, 40μm PVC films） study on hawthorn fruits storage quality indexes suggested that different packing processing had the effect of maintaining fresh quality of hawthorn fruits, could slow the decline of fruit firmness, reduce the loss of reducing sugar, titratable acid and vitamin C, and reduce the weightlessness rate and rot rate at the same time. Storage to 105 th day, the quality indexes of Hawthorn with film packaging treatments were better than the Contrast group. Comparison between three groups of film packaging processing, hawthorn fruits with 15 μm PE microporous film packaging processing, whose hardness, titratable acid content, Vc content, reducing sugar content had significant difference with the other two film packaging treatment groups（P < 0.05）. a* value was extremely significantly different with the other two groups（P<0.01）. The weight loss rate different with 15 μm PE film packaging treatment significantly（P<0.05）; The rot rate of hawthorn with 15 μm PE microporous film packaging treatment was 3.6%, 40 μm PVC film packaging treatment was 3.7%, both were respectively low. The results showed that, during the storage period of 105 days, 15 μm PE microporous film storage effect was the best.4. Different film packaging treatments（15 μm PE film, 15 μm PE microporous film, 40μm PVC film） research on hawthorn fruits storage quality indicators had shown that different film packaging treatments all were able to suppress the respiratory rate of hawthorn fruits, delay the peak of respiration and reduce its peak value, improve the antioxidant enzyme activity of POD, and inhibit the increase of MDA content and activity of PPO. Storage to 105 th days, the physiological indicators of hawthorn with film packaging treatments were better than the Contrast group. Comparison between three groups of film packaging processing, With 15 μm PE microporous film, 40 μm PVC film packaging treatments, Hawthorn fruits’ POD activity value was 1.09△OD470·min^-1·g^-1、1.15△OD470·min^-1·g^-1, both had significant difference with 15 μm PE film packaging treatment, the value was 0.76△OD470·min^-1·g^-1. With 15 μm PE microporous film packaging treatment, the hawthorn fruits’ PPO activity, MDA content were the lowest, the values were 0.0349△OD420·min^-1·g^-1、0.717μmol·g^-1; The respiratory intensity was 45.35 CO2mg·kg-1·h-1, significantly lower than the other two film packaging treatment groups（P<0.05）. The results showed that during the 105-day storage period, 15 μm PE microporous film did the best storage work.