| Fruits are naturally some fragrant and sweet plant fruit and seeds, we can eat them directly. Fruits are not only rich in nutrient and high edible value, but also have the function of health care 、anticancer and antigen. Otherwise, some fruits also have the healthy function of help ease blood pressure, delay aging, accelerate weight loss, skin wellness, brighten eyes, fight cancer, lower cholesterol, replenish the Vitamin and so on. Fruit storage period are usually for 2-3d under the room temperature. they are easily postharvest dehydration、contraction and decay, or caused lesions when affected by the extraneous interference and accompanied by lots of nutrients loss and quality decline,it eventually affect the fruit sales market. So to find a simple and practical method for fresh-keeping is an important content of fruit postharvest freshkeeping. There have been many studies on the fruit preservation technology at present and also achieved some results, but some equipment are high, some are hard to operate and some does have other side effects, which hamper the spreading and application. Therefore, using the most simple and effective way to keep the fruit quality and color was the important purpose of fruit postharvest preservation research. Through consulting relevant literature and the actual research of laboratories, we adopted the plant extracts preservation method and low doses of UV-B studied widely in recent years. In this research, we adopt the strawberry, cherry tomatoes, apples and winter jujubes as experimental materials. We mainly studied these four fruits appearance quality and internal physiological and biochemical changes in the process of storage when the concentration of the aloe Vera extract was at 0.5%, 0.35%, 0.25%, 0.1%, 0.05% and the irradiation time of UV-B at 30 min and 3h intervals. Main results are as follows:1. After the UV-B irradiation, the best exposure time of strawberry and apples were 60 min. And the best exposure time of winter jujubes and cherry tomatoes were 6h. By studying these four fruits quality and physiological and biochemical changes under the irradiation time of UV-B at 30 min and 3h intervals, we find that when strawberry and apples were under the 60 min irradiation time of UV-B, it can better inhibit the decline of fruit hardness and delay the rate of fruit surface and internal decay, and the content of vitamin C, the postharvest content of secondary metabolites, the content of the creator titration acid and fruit antioxidant activities were got some change mitigation compared with the other treatment and CK group. By preliminary test, cherry tomatoes and winter jujubes needed longer UV-B irradiation time. Although the best time is not the same, they have the same change trend with strawberry and apples. Thus, after the UV-B irradiation, the best exposure time of strawberry and apples were 60 min. And the best exposure time of cherry tomatoes and winter jujubes were 6h.2. When these four fruits at the concentration of aloe Vera extract was 0.05%, the preservation effect was more obvious. By studying these four fruits postharvest physiological and biochemical and quality changes at the concentration of aloe Vera extract was 0.5%、0.35%、0.25%、0.1%、0.05%. We find that when the treatment group was at the concentration of 0.05%, these four fruits firmness, rotting rate and quality change were restrained. Besides, the content of the external and internal soluble solids, postharvest secondary metabolites, soluble sugar, vitamin C, titration acid and fruit antioxidant activities have great difference with the other treatment and CK group. It has more preservation effect to these four fruits. Thus, when these four fruits at the concentration of aloe Vera extract was 0.05%, the preservation effect was more obvious.3. The preservation methods of low doses UV-B and aloe Vera extract may be have some insufficient places compared to other methods, but they are simple to operate and have fewer side effects, which convenient for the extension and utilization. In addition, we can do the compound preservation research with other preservation methods. The above results verified the use of low dose UV-B and aloe Vera extract can be used for fruit postharvest fresh-keeping. |
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