摘要
【目的】探讨鲁秀梨果实可溶性糖和有机酸含量的累积方式,为确定其适宜采收期与销售期提供依据。【方法】可溶性糖和有机酸含量的测定采用高效液相色谱法。【结果】鲁秀梨可溶性总糖主要由果糖、葡萄糖、蔗糖和山梨醇组成。从果实生长发育中后期至采收期,可溶性总糖含量是逐渐增加的。其中,前期的增加主要与果糖和葡萄糖含量的增加有关,其在花后100 d时含量达到最高;后期的增加主要与蔗糖在成熟前快速累积有关,山梨醇含量在整个测定时间变化幅度较小。采后贮藏至30 d时,可溶性总糖依旧呈上升趋势,但随后逐渐下降。有机酸主要是由苹果酸、柠檬酸、酒石酸、奎宁酸组成。总体上,苹果酸含量高于其他种类有机酸,为苹果酸优势型。因此,尽管柠檬酸含量在果实生长发育中后期是增加的,但有机总酸含量变化与苹果酸一致,即随着果实生长、成熟而降低。在贮藏期,有机酸含量呈继续下降趋势。【结论】鲁秀梨在果实发育中期和贮藏后期果糖和葡萄糖含量相对较高,而在果实采收时及贮藏前期蔗糖在总糖的占比较其他时期为高;整个测定期内,苹果酸含量始终高于柠檬酸含量,为苹果酸优势型果实。果糖、蔗糖和苹果酸可能是鲁秀梨果实特有风味的主要贡献因子。
【Objective】Luxiu is a new variety of pear(P.pyrifolia Nakai)bred by Qingdao Agricultural University with good balance of sugars and acids and pleasant flavor.The changes of the composition and contents of the soluble sugars and organic acids of the fruits of Luxiu during the development process and storage were studied in order to explore the accumulation mode of sugars and acids of the variety and to determine the suitable time for harvest and marketing.【Methods】The soluble sugars and organic acids were determined by high performance liquid chromatography.The fruits were selected for sampling on 80 d,100 d and 120 d(harvest time)after flowering,and the peel,middle pulp and nearcore pulp were sampled respectively.All the samples were frozen in liquid nitrogen and stored at-80℃【.Results】The total soluble sugars of Luxiu pear were mainly composed of fructose,glucose,sucrose and sorbitol.The sugar content in each measured part of the fruits was gradually increased from 80 d to 120 d after anthesis.There was no significant difference in the change tendency of sugar content between the middle pulp and the near-core pulp at the harvest time,but sugar contents of those two parts were significantly higher than that of the peel.However,the accumulation rate of total soluble sugar of the middle pulp was significantly higher than that of the near-core pulp and higher than that of the peel.The change trends of the sugar components in the three parts of the fruits were different.The early increase was mainly related to the increase of fructose,glucose,and the contents of these three sugars reached the highest value on 100 days after anthesis.The late increase of the sugar content was mainly related to the rapid accumulation of sucrose before maturity.The content of sorbitol did not change significantly during the whole determination period.After 30 days of postharvest storage,the total soluble sugar still showed an upward trend,and then it gradually decreased.The contents of fructose and glucose had the same change trend during the storage period,both of them decreased first,reached the lowest value on 60 days of storage,then increased,and decreased again during the late storage period.The content of sorbitol was similar to those of fructose and glucose,but increased after 30 days of storage compared with that on 0 d.The change trend of sucrose content,which was different from the other three kinds of sugar,increased continuously after harvest,reached the highest value on 60 days,then decreased.The organic acids of Luxiu pear fruits were mainly composed of malic acid,citric acid,tartaric acid and quinic acid.On the whole,the content of malic acid was higher than those of citric acid and other organic acids,so it could be considered as the dominant acid.The change of total organic acid content was consistent with that of malic acid,which decreased with the growth and ripening of the fruits.Although the citric acid content increased with the development of the fruits,it was always lower than that of the malic acid.The content of organic acids of the peel was lower than those of the pulp and near-core part.The changes of organic acid content of middle pulp and the near-core pulp was similar,which decreased significantly on 100 d after anthesis and kept this level until harvest.At the early stage of storage,the content of organic acids continued to decrease,and reached the lowest value on 60 d.The contents of malic acid and oxalic acid decreased at early storage and reached the lowest value on 30 d and 60 d of storage respectively.The contents of citric acid,quinic acid and shikimic acid did not change significantly during storage.【Conclusion】The contents of fructose,glucose and sorbitol of the Luxiu pear fruits were relatively higher in mid-development stage and late storage time,while the contents of sucrose of the fruits were relatively higher during harvest and early storage time.The content of malic acid was always higher than that of citric acid during the whole tested period.The fructose,sucrose and malic acid might be the main contributing factors to the special flavor of the Luxiu pear fruits.
作者
刘清鹤
荆琳
王成荣
宋健坤
杨英杰
李鼎立
王然
LIU Qinghe;JING Lin;WANG Chengrong;SONG Jiankun;YANG Yingjie;LI Dingli;WANG Ran(Horticultural College,Qingdao Agricultural University/Qingdao Key Laboratory of Horticultural Plant Genetic Improvement and Breeding,Qingdao 266109,Shandong,China)
出处
《果树学报》
CAS
CSCD
北大核心
2022年第5期743-751,共9页
Journal of Fruit Science
基金
山东省良种工程(2019LZGC008)
青岛市民生科技计划项目(19-6-1-67-nsh)
国家现代农业产业技术体系(CARS-29-07)。
关键词
梨
生长期
贮藏期
糖酸含量
Pear
Growing period
Storage period
Sugar and acid content
