压差预冷对油桃贮运品质及抗氧化性的影响

Improving quality and antioxidant capacity of nectarine by forced-air precooling during storage and transportation

以‘曙光’油桃为试材,在产地进行压差预冷,经运输48 h后,置于(0±0.3)℃条件下贮藏60 d,测定和分析贮藏期间油桃的呼吸代谢,品质营养指标及抗氧化性的变化。结果表明,与普通冷库预冷相比,压差预冷显著缩短了油桃的预冷时间,减缓了运输期间的回温速率,抑制了果实在贮藏期间的呼吸强度和乙烯释放速率,推迟了呼吸高峰出现时间,保持了较高的硬度、可溶性固形物、可滴定酸、抗坏血酸、总黄酮和总酚含量,降低了失重率、腐烂率和丙二醛含量的积累;贮藏结束时(60 d),压差预冷处理组的油桃1,1-二苯基-2三硝基苯肼(1,1-diphenyl-2-trinitrophenylhydrazine,DPPH)自由基清除能力、2,2'-联氮双(3-乙基苯并噻唑啉-6-磺酸[2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid,ABTS]自由基清除能力和铁离子还原能力(ferric reducing antioxidant power,FRAP)分别比普通预冷组高出10.59%、22.35%和20.27%。因此,压差预冷可提高油桃的贮运品质和抗氧化性,是实际生产中宜采用的预冷方式。

To evaluate the quality and antioxidant potential of‘Shuguang’nectarine fruits during storage and transportation,the treatment of forced-air pre-cooling was applied.Forced-air pre-cooling was carried out in the refrigeration house of nectarine producing region.After transportation for 48 h,the nectarine fruits were stored at(0±0.3)℃for 60 d.Changes in respiration metabolism,quality,nutritional characteristics and antioxidant capacity were analyzed.The result showed that forced-air pre-cooling significantly reduced the pre-cooling time of nectarines,and slowed down the rate of temperature return during transportation.During storage,forced-air pre-cooling inhibited fruit respiration intensity and ethylene release rate,and delayed the peak time of respiration.Nectarine treated by forced-air pre-cooling showed better hardness and higher content of soluble solids,titratable acid,ascorbic acid,total flavonoids,total phenol.It also reduced the weight loss,decay rate and could accumulate the malondialdehyde.At the end of the storage(60 d),the ferric reducing antioxidant power(FRAP),scavenging capacity of DPPH and ABTS of nectarine treated by forced-air pre-cooling were 10.59%,22.35%and 20.27%respectively,which higher than that by normal pre-cooling.To conclude,forced-air pre-cooling can improve the storage quality and oxidation resistance of nectarine during storage and transportation.