牛油果果实发育过程中营养物质含量变化研究

Changes of nutrient content during thedevelopment of avocado(Persea americana)fruit

关键词:  牛油果, 采收期, 粗脂肪, 氨基酸, 矿质元素, 灰分

Key words:  avocado(Persea americana), harvest time, crude fat, amino acids, mineral element, ash

摘要:

为确定牛油果的最佳采收期,阐明牛油果生长发育过程中营养物质的累积变化规律。该文采用电感耦合等离子体发射光谱法、灼烧法、茚三酮柱后衍生离子交换色谱法、回流提取法和GC-MS联用技术,研究了‘HASS'‘V3'和‘V4' 3个品种牛油果果实中粗脂肪、氨基酸、矿质元素以及灰分在6—12月间的含量变化。结果表明:(1)3个品种牛油果中油脂的主要成分均为油酸,其中‘HASS'和‘V4'果实中的粗脂肪含量在12月达到峰值,而‘V3'果实中的粗脂肪含量则在10月达到峰值,之后有所下降。(2)3个品种牛油果中均含有17种氨基酸,包括7种人体必需氨基酸、2种儿童必需氨基酸以及8种人体非必需氨基酸,其中‘HASS'和‘V3'果实中的17种氨基酸含量在11月达到峰值,而V4的则在10月达到峰值。(3)3个品种牛油果中均含有磷(P)、钾(K)、钙(Ca)、镁(Mg)、锌(Zn)、铁(Fe)、锰(Mn)、铜(Cu)、钠(Na)9种矿质元素,其中P、K、Zn、Fe、Na含量在10—12月累积至最大,其余4种矿质元素变化规律不明显。(4)灰分含量变化规律与粗脂肪相似。综上认为,3个品种牛油果的营养物质均在10月达到最佳值,可以根据需求进行采收。该研究结果为确定牛油果的最佳采收时间提供了科学依据。

Abstract:

In order to provide a scientific basis for optimum harvest time, the nutrient changes of avocado(Persea americana)fruit during the growth and development were studied. An approach of inductively coupled plasma atomic emission spectrometry, ion exchange chromatography derived after ninhydrin column, reflux extraction, burning and GC-MS technique were applied to determine the contents of mineral elements, ash, amino acids, crude fat, and fatty acid composition in three avocado cultivars(‘HASS'‘V3' and ‘V4'), 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 stages, and reached to the maximum on December, while V3 fruit increased continuously from June to October, while decreased in November and December.(2)All fruits of ‘HASS'‘V3' and ‘V4' contained 17 kinds of amino acids, including seven essential(Thr, Met, Val, Leu, Ile, Phe, Lys)for human beings, two essential(Arg, His)for children, and eight non-essential(Pro, Tyr, Cys, Ala, Gly, Glu, Ser, Asp)amino acids. The contents of 17 amino acids in ‘HASS' and ‘V3' fruits reached to the peak in November, while ‘V4' fruits reached to the peak in October.(3)All the ‘HASS'‘V3' and ‘V4' fruits contained nine mineral elements of P, K, Ca, Mg, Zn, Fe, Mn, Cu and Na. Among which, the contents of P, K, Zn, Fe and Na accumulated to the maximum in the later stages of growth(October to December), 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 conclusion, It suggests that the three studied avocado cultivars, ‘HASS'‘V3' and ‘V4', 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.