Page 194 - 《广西植物》2023年第5期
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5 期 唐妮等: 牛油果果实发育过程中营养物质含量变化研究 9 6 1
emission spectrometryꎬ ion exchange chromatography derived after ninhydrin columnꎬ reflux extractionꎬ burning and GC ̄
MS technique were applied to determine the contents of mineral elementsꎬ ashꎬ amino acidsꎬ crude fatꎬ and fatty acid
composition in three avocado cultivars (‘HASS’‘V3’ and ‘V4’)ꎬ at different growth and development time from June
to December. The results were as follows: (1) Oleic acid was the main oil component in the three avocado cultivars. The
contents of crude fat in ‘HASS’ and ‘V4’ fruits increased continuously during the growth and development stagesꎬ and
reached to the maximum on Decemberꎬ while V3 fruit increased continuously from June to Octoberꎬ while decreased in
November and December. (2) All fruits of ‘HASS’‘V3’ and ‘V4’ contained 17 kinds of amino acidsꎬ including seven
essential (Thrꎬ Metꎬ Valꎬ Leuꎬ Ileꎬ Pheꎬ Lys) for human beingsꎬ two essential (Argꎬ His) for childrenꎬ and eight
non ̄essential (Proꎬ Tyrꎬ Cysꎬ Alaꎬ Glyꎬ Gluꎬ Serꎬ Asp) amino acids. The contents of 17 amino acids in ‘HASS’ and
‘V3’ fruits reached to the peak in Novemberꎬ while ‘V4’ fruits reached to the peak in October. (3) All the ‘HASS’
‘V3’ and ‘V4’ fruits contained nine mineral elements of Pꎬ Kꎬ Caꎬ Mgꎬ Znꎬ Feꎬ Mnꎬ Cu and Na. Among whichꎬ the
contents of Pꎬ Kꎬ Znꎬ Fe and Na accumulated to the maximum in the later stages of growth (October to December)ꎬ
while the changes for the other four mineral elements were not obvious. (4) The variation of ash contents in the three
avocado cultivars was similar to that of the crude fat. In conclusionꎬ It suggests that the three studied avocado cultivarsꎬ
‘HASS’‘V3’ and ‘V4’ꎬ have met the picking requirements since October and can be optimized the harvest time
following fluctuations in demand. The results provide a scientific basis for determining the best time to harvest
avocados.
Key words: avocado (Persea americana)ꎬ harvest timeꎬ crude fatꎬ amino acidsꎬ mineral elementꎬ ash
牛油果(Persea americana)ꎬ英文名 avocadoꎬ又 降低、营养欠佳、风味和口感下降ꎬ而且容易引起
名鳄梨、樟梨或油梨ꎬ为樟科( Lauraceae) 鳄梨属 后熟过程延长、后熟不充分甚至引起果实腐烂ꎻ而
(Persea)常绿乔木ꎮ 最早起源于南美洲ꎬ现已遍及 采收过晚则不利于储藏及运输ꎬ同时对果树营养
全球热带和亚热带地区ꎬ以墨西哥、智利、多米尼 的耗费增加ꎬ不利于果树的生长( 陈彦同ꎬ2006ꎻ袁
加共和国、美国南部、哥伦比亚、秘鲁、危地马拉、 怀榆等ꎬ2020)ꎮ 因此ꎬ确定科学合理的指标以指
古巴及印度尼西亚等地栽培为主( Bhuyan et al.ꎬ 导牛油果的采收十分重要ꎮ
2019)ꎮ 牛油果果实富含脂肪ꎬ以亚麻酸、油酸等 牛油果果实最主要的营养物质为油脂ꎬ以不
单不饱和脂肪酸为主ꎬ还含有蛋白质、维生素及各 饱和脂肪酸的含量较高( Donetti & Terryꎬ 2014)ꎮ
种矿物质ꎮ 牛油果果实具有健胃清肠、降糖降脂、 根据品种和生长条件不同ꎬ牛油果果实中的含油
降血压、抗癌以及保护心血管和肝脏系统等功效 量在 8% ~ 30%之间ꎬ并且采收后无明显变化( Lee
(Dreher et al.ꎬ 2013)ꎮ 我国自 19 世纪初引进ꎬ现 et al.ꎬ1983ꎻ Quiñones ̄Islas et al.ꎬ 2013)ꎮ 牛油果
已在广东、广西、福建、云南、四川和海南等地推广 中的油 脂 类 成 分 主 要 由 单 不 饱 和 油 酸 ( 50% ~
栽培(钱学射等ꎬ2011)ꎮ 60%)、饱和棕榈酸(15% ~ 20%)、不饱和棕榈油酸
水果中的营养成分含量通常是判断果实生理 (6% ~ 10%)、多不饱和亚油酸(11% ~ 15%) 和亚
成熟的标准ꎮ 例如ꎬ猕猴桃的采收标准以果实中 麻酸( ± 1%) 组成( Donetti & Terryꎬ 2014)ꎮ 果实
可溶性固形物达到 6.2%为最低限度成熟度( 李瑞 中的油含量和成分是衡量牛油果成熟度的重要指
高等ꎬ1985)ꎻ可溶性固形物和果实硬度为梨的采 标ꎬ而不同品种牛油果的最低采收标准却有所不
收指标(崔建潮等ꎬ2019)ꎮ 与猕猴桃、梨等大多水 同ꎮ 例如ꎬ墨西哥系牛油果以含油量 8%为采收标
果不同ꎬ牛油果果实在达到最低收获成熟度后ꎬ可 准ꎬ危地马拉系和西印度系牛油果分别以含油量
以挂在树上长达 12 个月ꎬ而刚采摘下的果实却未 7.5% ~ 18%和 5% ~ 7%为标准(陈金表ꎬ1985)ꎮ
达到食用要求ꎬ需要经过一定时期的后熟过程方 除了油脂以外ꎬ牛油果中还富含多种氨基酸
可食用( Hurtado ̄Fernández et al.ꎬ 2016ꎻ 曹森等ꎬ 及矿质元素ꎬ其含量对果实的香气、滋味、口感等
2018)ꎮ 然而ꎬ牛油果是否达到采收标准ꎬ仅从外 品质具有较大影响 ( Pedreschi et al.ꎬ 2019)ꎮ 因
观却较难判定ꎮ 采收过早ꎬ不仅造成牛油果产量 此ꎬ除了脂肪含量以外ꎬ氨基酸、矿质元素等营养