瓶装椰子汁沉淀的理化性质和来源分析

Physico-Chemical Properties and Causes of the Precipitates in Bottled Coconut Juice

摘要:

本文通过显微镜观察、粒度分析、化学组分测定、ICP-MS和扫描电镜观察等方法，分析了椰子汁沉淀的宏观结构、粒度分布、化学组成和微观结构及其来源。与椰子汁乳化颗粒相比，沉淀颗粒色泽灰暗，颗粒偏大、形状不规整、容易抱团聚集。90%，50%和10%的沉淀颗粒分别在184.00 μm，41.90 μm和3.86 μm以下。矿物盐、粗纤维和可水解总糖构成了沉淀主要成分，含量分别为38.53%，29.73%和26.32%。沉淀中含有大量Mg、Fe、P和Ca等容易形成沉淀的矿物元素，含量分别是1.64%、0.21%、5.10%和6.75%。电子显微镜观察大沉淀颗粒（50 μm以上）大部分呈不规则块状，表面粗糙，少部分呈片状，而细小的颗粒（10 μm以下）呈大小不一的球形，表面光滑。看来不同成分沉淀的来源不同。

Abstract:

In this paper, the macroscopic structure, particle size distribution, chemical composition, microstructure, and source of coconut juice precipitation were analyzed by microscopy, particle size measurement, inductively coupled plasma mass spectrometry, and scanning electron microscopy. Compared to the emulsion particles of coconut juice, the precipitate particles were dark in color, had relatively large sizes with irregular shape, and tended to aggregate. Moreover, 90%, 50%, and 10% of the precipitates sized below 184.00 μm, 41.90 μm and 3.86 μm, respectively. The precipitates in coconut juice were mainly composed of mineral salt (38.53%), crude fiber (29.73%), and hydrolyzable sugars (total content: 26.32%). The precipitates contained high contents of easily precipitated mineral elements such as Mg (1.64%), Fe (0.21%), P (5.10%), and Ca (6.75%). Scanning electron microscopy showed that most of the large precipitate particles (> 50 μm) were irregularly shaped and had rough surfaces along with a small number of flaky particles, whilst the small spherical particles (< 10 μm) with different sizes were spherical in size and smooth in appearance. It seemed that different causes led to the generation of precipitates with different compositions.