农业工程学报
農業工程學報
농업공정학보
2014年
17期
285-294
,共10页
刘峰娟%孟阳%白羽嘉%刘春月%黄文书%冯作山
劉峰娟%孟暘%白羽嘉%劉春月%黃文書%馮作山
류봉연%맹양%백우가%류춘월%황문서%풍작산
水果%脱水%品质控制%脱水速度%无核白葡萄%膜脂过氧化%褐变
水果%脫水%品質控製%脫水速度%無覈白葡萄%膜脂過氧化%褐變
수과%탈수%품질공제%탈수속도%무핵백포도%막지과양화%갈변
fruit%dehydration%quality control%dehydration speed%Thompson seedless grapes%membrane lipid super oxidization%browning
为探索脱水速度对无核白葡萄干制过程中膜脂过氧化作用及褐变的影响，以新疆无核白葡萄为试验材料，经过葡萄促干剂处理后，采用快速脱水和缓慢脱水2种处理，质量每减轻10%进行取样，测定脱水过程中果实干基含水率、干燥速率、褐变度、细胞膜透性、丙二醛（malonaldehyde，MDA）含量、脂氧合酶（lipoxygenase，LOX）、超氧化物歧化酶（superoxide dismutase，SOD）、过氧化氢酶（catalase，CAT）、过氧化物酶（peroxidase，POD）、多酚氧化酶（polyphenol oxidase，PPO）活性以及总酚含量的变化。结果表明：与缓慢脱水相比，快速脱水处理显著（P<0.05）降低了无核白葡萄褐变度的上升，减少MDA生成量以及膜透性的增加，抑制LOX活性的升高，保持较高的活性氧清除酶SOD、CAT及POD活性及较高的总酚含量，且使PPO活性保持在一个较低的水平。因此认为，快速脱水可以有效地抑制无核白葡萄的膜脂过氧化作用对细胞膜的破坏，保持细胞的完整性，且PPO活性较低，从而减少无核白葡萄脱水褐变的发生。研究结果为快速脱水在无核白葡萄干制中的应用提供参考。
為探索脫水速度對無覈白葡萄榦製過程中膜脂過氧化作用及褐變的影響，以新疆無覈白葡萄為試驗材料，經過葡萄促榦劑處理後，採用快速脫水和緩慢脫水2種處理，質量每減輕10%進行取樣，測定脫水過程中果實榦基含水率、榦燥速率、褐變度、細胞膜透性、丙二醛（malonaldehyde，MDA）含量、脂氧閤酶（lipoxygenase，LOX）、超氧化物歧化酶（superoxide dismutase，SOD）、過氧化氫酶（catalase，CAT）、過氧化物酶（peroxidase，POD）、多酚氧化酶（polyphenol oxidase，PPO）活性以及總酚含量的變化。結果錶明：與緩慢脫水相比，快速脫水處理顯著（P<0.05）降低瞭無覈白葡萄褐變度的上升，減少MDA生成量以及膜透性的增加，抑製LOX活性的升高，保持較高的活性氧清除酶SOD、CAT及POD活性及較高的總酚含量，且使PPO活性保持在一箇較低的水平。因此認為，快速脫水可以有效地抑製無覈白葡萄的膜脂過氧化作用對細胞膜的破壞，保持細胞的完整性，且PPO活性較低，從而減少無覈白葡萄脫水褐變的髮生。研究結果為快速脫水在無覈白葡萄榦製中的應用提供參攷。
위탐색탈수속도대무핵백포도간제과정중막지과양화작용급갈변적영향，이신강무핵백포도위시험재료，경과포도촉간제처리후，채용쾌속탈수화완만탈수2충처리，질량매감경10%진행취양，측정탈수과정중과실간기함수솔、간조속솔、갈변도、세포막투성、병이철（malonaldehyde，MDA）함량、지양합매（lipoxygenase，LOX）、초양화물기화매（superoxide dismutase，SOD）、과양화경매（catalase，CAT）、과양화물매（peroxidase，POD）、다분양화매（polyphenol oxidase，PPO）활성이급총분함량적변화。결과표명：여완만탈수상비，쾌속탈수처리현저（P<0.05）강저료무핵백포도갈변도적상승，감소MDA생성량이급막투성적증가，억제LOX활성적승고，보지교고적활성양청제매SOD、CAT급POD활성급교고적총분함량，차사PPO활성보지재일개교저적수평。인차인위，쾌속탈수가이유효지억제무핵백포도적막지과양화작용대세포막적파배，보지세포적완정성，차PPO활성교저，종이감소무핵백포도탈수갈변적발생。연구결과위쾌속탈수재무핵백포도간제중적응용제공삼고。
Xinjiang is abundant in grapes. According to statistics, the production of grape accounted for 28.4%of the whole fruit production in Xinjiang in 2012. Since the mature period of grapes is very short, dehydrated drying after grape harvest is an important method of processing. Thompson seedless grape (Vitis vinifera L. var Wuhebai) is the main species of green raisins. As green raisins produced from traditional dry room are likely to browning, it’s well acknowledged as a key issue for the development of Xinjiang raisins. It was reported that the browning of actinidia arguta, longan, litchi and peach was caused by the polyphenol oxidase (PPO) contacting with the phenolic substrates, which resulted in the strengthen of the membrane lipid peroxidation and the increase of cell membrane permeability in fruits. These researches were focused on the relationship between browning caused by dehydration treatment before storage or nature water loss during storage and the membrane lipid peroxidation. But the dehydration was different from dehydration drying process. In order to investigate the mechanism that rapid dehydration inhibited the membrane lipid peroxidation, PPO, browning of Thompson seedless grapes during the drying, the changes of physiological and biochemical properties caused by grape browning in dehydration drying process were investigated in this study, and subsequently obtained the theoretical basis for preventing raisins browning and maintaining the quality of Thompson seedless grapes. Xinjiang Thompson seedless grapes were used as experiment materials. After being operated by the drying agent, two treatments, i.e. rapid dehydration and slow dehydration were conducted. Samples were taken every 10%loss in weight of the samples and stored for further use. The effects of different drying methods on dry basis moisture content, drying rate, browning, membrane permeability (relative conductivity), malonaldehyde (MDA) content, lipoxygenase (LOX) activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, peroxidase (POD) activity, polyphenol oxidase (PPO) activity and total phenol content were studied. The results showed that there were two stages in the drying of Thompson seedless grapes, i.e. constant rate drying and falling rate drying, and the significant browning of Thompson seedless grape during two drying methods both occured in the falling rate drying stage. The browning of Thompson seedless grape in the slow dehydration was in positive correlation with LOX activity, and the browning of Thompson Seedless grape in the rapid and slow dehydrations was in positive correlation with membrane permeability and MDA content, and negatively correlated to SOD activity, CAT activity, PPO activity, and total phenols content. It was found that the browning in the dehydration process of Thompson seedless grapes was closely related to the membrane lipid peroxidation. Rapid dehydration treatment significantly slowed down the development of the browning, as well as MDA content and membrane permeability; besides, LOX activity was also inhibited. The relatively high activity of active oxygen scavenging enzymes including SOD, CAT and POD and the more content of total phenols were maintained, and PPO was kept at a low level of activity. In conclusion, rapid dehydration can effectively inhibit the membrane lipid peroxidation of Thompson seedless grapes from cell membrane damage, maintain the integrity of the cells, and retard the browning of Thompson seedless grapes during drying and heating processes. The results provide a reference for the application of rapid dehydration in the drying of Thompson seedless grapes.
