摘要
柑橘果皮表面覆盖着一层蜡质,具有多重重要的生理功能。以温州蜜柑(Citrus unshiu Marc.)和冰糖橙(Citrus sinensis Osbeck)果实为原料,采用气相色谱-质谱联用(gas chromatography-mass spectrometry,GC-MS)对2种类型柑橘果皮角质层组分进行定性和定量分析,并采用扫描电子显微镜对其微观结构进行观察。GC-MS分析表明,温州蜜柑和冰糖橙外蜡含量分别为3.7μg/cm^2和2.2μg/cm^2,内蜡含量分别为13.9μg/cm^2和18.4μg/cm^2。温州蜜柑和冰糖橙的外、内蜡中脂肪族物质主要成分相同,分别为烷烃、脂肪酸、伯醇,但品种间各组分比例及碳原子数分布存在差异。角鲨烯为冰糖橙果实外蜡结构特有组分。此外,三萜类物质仅在内蜡中检测出。温州蜜柑和冰糖橙的角质膜层含量分别为44.00μg/cm^2和70.00μg/cm^2,二者含量差异显著(P<0.05)。扫描电子显微镜结果显示温州蜜柑的外蜡晶体呈不规则血小板状,冰糖橙的外蜡晶体呈倒伏的血小板状。除去外蜡导致温州蜜柑和冰糖橙的水分损失速率显著增加(P<0.05)。相对于脂肪酸,烷烃在保水方面具有更重要的作用。两种类型柑橘的角质层组分及微观结构的差异可能促成了果实采后不同的贮藏特性,这为提高不同品种柑橘耐贮性提供了重要依据。
The surface of citrus peel is covered with a layer of wax,exerting multiple important physiological functions.The qualitative and quantitative analysis of cuticular components in the fruit peel of Satsuma mandarin(Citrus unshiu Marc.)and Bingtang sweet orange(Citrus sinensis Osbeck)were carried out by gas chromatography-mass spectrometry(GC-MS).Scanning electron microscopy(SEM)was used to observe the difference in the cuticle microstructure of Satsuma mandarin and Bingtang sweet orange.GC-MS results showed that the epicuticular wax contents of Satsuma mandarin and Bingtang sweet orange were 3.7 and 2.2μg/cm2,respectively,and the intracuticular wax contents were 13.9 and 18.4μg/cm2,respectively.The major aliphatic components of epicuticular and intracuticular wax in two citrus cultivars were identical,including alkanes,fatty acids,and primary alcohols,but their proportions and carbon number distribution were dependent on cultivars.Farnesol was found to be exclusively present in the epicuticular wax of Bingtang sweet orange.Moreover,triterpenoid compounds were detected only in the intracuticular wax.The cutin contents of Satsuma mandarin and Bingtang sweet orange were 44.00 and 70.00μg/cm2,respectively,being significantly different.SEM showed irregular platelet flattened platelet waxes to be deposited on the surface of Satsuma mandarin and Bingtang sweet orange,respectively.The removal of epicuticular wax could cause a significant increase of water loss rate in Satsuma mandarin and Bingtang sweet orange(P<0.05).Compared with fatty acids,alkanes played a more significant role in water retention in fruits.The differences in the chemical composition and microstructure of cuticle between citrus varieties may contribute to the differences in postharvest storage characteristics,which will provide important evidence for improving the storage quality of different citrus varieties.
作者
张静
丁胜华
谢秋涛
付复华
王蓉蓉
李高阳
单杨
ZHANG Jing;DING Shenghua;XIE Qiutao;FU Fuhua;WANG Rongrong;LI Gaoyang;SHAN Yang(Longping Branch Graduate School,Hunan University,Changsha 410125,China;Hunan Agricultural Product Processing Institute,Hunan Academy of Agricultural Sciences,Changsha 410125,China;College of Food Science and Technology,Hunan Agricultural University,Changsha 410128,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2018年第7期131-138,共8页
Food Science
基金
湖南省自然科学基金项目(2016JJ6077)
国家自然科学基金青年科学基金项目(31501543)
公益性行业(农业)科研专项(201303076)
农业科研杰出人才及其创新团队项目(农办人[2012]64号)
"万人计划"领军人才项目(财教[2014]412号)
