降温方法对不同成熟度鸭梨果肉脂氧合酶活性和膜脂脂肪酸的影响  

Effect of different cooling methods on LOX activity and membrane fatty acid of different maturity Yali pear after harvest

作　　者：梁丽雅[1] 胡小松[2] 何爱红[3] 汪政富[2] 闫师杰[1] 

机构地区：[1]天津农学院食品科学系,天津300384 [2]中国农业大学食品科学与营养工程学院,北京100083 [3]北京商贸学校,北京100076

出　　处：《食品科技》2012年第4期35-39,共5页Food Science and Technology

基　　金：国家自然科学基金项目(31171767;30600424)

摘　　要：为了探讨缓慢降温抑制采后鸭梨果实褐变的机理,研究了不同降温方法对不同成熟度鸭梨果肉脂氧合酶(LOX)活性及膜脂脂肪酸组分和含量的影响。结果表明:在贮藏期间,LOX活性缓慢上升,晚采果活性较高;缓慢降温抑制了LOX活性的升高和果肉褐变,对早采果影响明显。鸭梨果肉中含有月桂酸、豆蔻酸、棕榈酸、棕榈油酸、珠光酸、硬脂酸、油酸、亚油酸、亚麻酸,其中含量较多的是亚油酸、棕榈酸和油酸。推迟采收和缓慢降温提高了果肉的U/S值,缓慢降温提高了鸭梨果肉的亚麻酸及前期的亚油酸含量,在贮藏后期,随着LOX活性的升高,亚油酸、亚麻酸的含量减少,二者可能是LOX的反应底物。适当早采结合缓慢降温可提高鸭梨果肉膜脂不饱和脂肪酸含量和U/S值,抑制果肉褐变。In order to investigate the mechanism that slow cooling inhibits browning of Yali after harvest,the effect of different cooling methods on membrane fatty acid components,contents,lipoxygenase（LOX） activity of flesh of Yali pear with different harvest period were studied.The results showed that LOX activity of Yali pear raised slowly and was higher in late harvest fruit during storage.Slow cooling inhibited LOX activity and browning of the flesh,it had obvious effect on early harvest fruit.Fatty acid components in flesh contained lauric acid,tetradecanoic acid,palmitic acid,palmitoleic acid,perlatolic acid,stearic acid,oleic acid,linoleic acid,linolenic acid.The content of linoleic acid,palmitic acid and oleic acid were higher than the other kinds of fatty acid.Late harvest and slow cooling obviously increased the U/S value in flesh of Yali.Slow cooling increased the content of linolenic acid and linoleic acid in flesh in early time during storage of Yali,and the content of linoleic acid and linolenic acid decreased along with the rise of LOX activity in the later period of storage,these two acids were possibly the reactive substrates of LOX.Early harvesting and slow cooling could increase the contents of unsaturated fatty acid and U/S value of flesh,restrain the flesh browning of Yali pear after harvest.

关 键 词：鸭梨 降温方法 成熟度 果肉 LOX 脂肪酸 

分 类 号：TS255.3[轻工技术与工程—农产品加工及贮藏工程]