Storage Control for Fresh Ya Pear
When the Ya pear is kpet at 0.5 ℃ of average storage temperature , it will cause the longest storage period . If the temperature is Below-1℃, large temperature fluctuations will bring out frostbite, black hearts and red flesh. The water content of Ya pear is as high as 88%, so a relative humidity is required for appropriate storage with 90-95%. However, too high humidity is also easy to rot, and low humidity is easy to cause dry scars, peel shrinkage, hardness decline even cause loss of commercial value. Ya Pear storage has strict gas requirements. Different from other fruits, it requires a higher concentration of oxygen and a lower concentration of carbon dioxide, and the environmental carbon dioxide content in the reservoir cannot be above 1% for a long time. In order to achieve the longest storage period and maintain good quality of Ya Pear, Ya pear is required to be stored in the warehouse quickly after harvesting. According to the past experience , delaying for storage will cause the early senescence of fruits, which will increase the black heart rate during storage. For example, the warehouse No. 7 will be stored on September 15-19, and the warehouse No. 1 will be stored on September 20-28. To be checked on December 26, the black heart rates were 0.5% and 20% respectively. During storage for Ya pear, if it is stored under hypoxic conditions, which will cause physiological disorders, and the normal metabolic process of the fruit will be disturbed and destroyed, leading to increased respiratory intensity, will cause the fruit to deteriorate, taste change and rot. Therefore, ventilation shall be required when placecd on pallets.
After harvesting different sizes of fruits, under the same storage conditions and at the same temperature, the large size (single fruit weighs 250 grams) has large breathing intensity, and the fruit hardness decreases quickly, which is no good for long storage of Ya Pear. Therefore, large-sized products must be sold out of the warehouse before the end of December, and the medium-sized fruits have low respiratory intensity, which can be stored in long period of time. After the fruit is harvested, the water is still transpiration everywhere, which is the main reason for the natural loss of the fruit. With the transpiration of water, the turgor of fruit cells decreases, which gradually leads to wilt. After the fruit is harvested in September and stored until April-May of the following year, the total loss rate of the fruit is about 3-4% of the weight of the fruit. Amoung the total 3-4%, aroundt one-fifth is referring to respiratory loss, and the remaining four-fifths is due to transpiration. Generally, when the dehydration rate of the fruit reaches 5%, it wil lcause the surface part of the fruit to shrink, losing its fresh appearance and cell texture. These will destroy the normal metabolism,and cause the physiological disorder of the fruit. Some internal factors and external conditions of fruit will affect the transpiration of fruit water. The fruit's epidermis contains keratin and wax that prevent water from evaporating. As the fruit matures, the stratum corneum and waxy layer gradually become thicker and the structure is more complete. The content of protoplasmic hydrocolloids and soluble substances in fruit cells will increase, which will make the cells have strong water retention. If the cuticle and waxy layer are not formed before harvest, dry scars and shrinkage will occur. Therefore, it must be harvested in time to maintain the original flavor of the fruit. The water pressure in the cell gap of Yali fruit generally reaches or approaches the saturated water steam pressure. When the actual water steam pressure in the surrounding air is low and there is still a large amount of water vapor in the air, the water in the fruit will continue to flow out. Therefore, Transpiration,he degree of humidity saturation in the air of warehouse is the direct reason for affecting the transpiration intensity of fruit moisture. Taking use of nitrogen fertilizer at the late stage of Ya pear’s growth will increase the occurrence of physiological diseases. A large amount of irrigation before the fruit is harvested can also affect the storability of the fruit. Fruits that are harvested at the right time have high storage stability, but because they cannot be stored at a suitable low temperature in time, allowing the fruit to pass through the appropriate storage stage will lead to a decline in storage resistance. Therefore, we must place great emphasis on timely storage.