Effects Of Differently Chemical Treatments On Preservation In Huanghua Pear And Kiwifruit Fruit During Storage

Harvested Huanghua pear fruit (Pyrus pyrifolia Nakai) were dipped in solution of5mmol·L-1oxalic acid (OA),0.1g·L-1salicylic acid (SA),2%calcium chloride (CaCl2) or water (as control) for15min, and then stored at (4±0.5)℃. Effects of these treatments on senescence, antioxidant metabolism and quality change in fruit were investigated during cold storage. The main results were as follow:As compared to control, three treatments delayed the decline of fruit firmness and color L value, inhibited the rise of weight loss rate, reduced respiration rate and delayed appearance of its peak, which caused a higher soluble solids (SSC), titritable acidity (TA) and soluble protein contents in fruit at the latter days in storage. The results showed that these treatments effectively delayed fruit browning, softening and senescence by inhibiting respiration metabolism, and oxalic acid treatment was presented the best effect.The three treatments inhibited lipoxygenase (LOX) activity, and increased catalase (CAT) activity and ascorbic acid (AsA) content accompanied with a decrease in malondialdehyde (MDA) content and hydrogen peroxide content in latter storage period. In addition, OA and SA treatment maintained higher peroxidase (POD) activity in early storage. Therefore, these treatments effectively improved the antioxidant capacity, which might be contributed to delaying the ripening process and improving sensory quality and nutrition quality of the fruit.Fruits and leaves of kiwifruit (Actinidia eriantha.cv. White) were sprayed with1.5mmol·L-1salicylic acid (SA)+10mg·L-1naphthyl acetic acid (NAA), or5mmol·L-1oxalic acid (OA)+10mg·L-1naphthyl acetic acid (NAA), or1.5mmol·L-1SA, or5mmol·L-1OA, or water (as control) at40days before harvest, and these treatments were applied for3times at7-day intervals. The kiwifruits were harvested and stored at room temperature (20±1℃). The effects of pre-harvest treatments on storability and fruit in kiwifruits were investigated. The main results were as follows:As compared to the control, these pre-harvest treatments increased fruit firmness, color b value, the content of SSC at early storage period and AsA at latter storage period, decreased respiration rate and fruit incidence, and inhibited decrease in TA. On other hand, pre-harvest (SA+NAA) treatment,(OA+NAA) treatment and SA treatment decreased fruit weight loss rate, OA and S A treatments inhibited the degradation of chlorophyll. In addition, these pre-harvest treatments increased contents of some minerals including K, Ca, Mg, Na and Fe, and organoleptic quality of these pre-harvest treatments fruits was higher than that of control. Therefore, these pre-harvest treatments could extend storage time and improve fruit quality of the kiwifruit.