乌桕类可可脂结晶过程中表现体积变化

THE CHANGE OF APPARENT VOLUME OF CHINESE TALLOW COCOA BUTTER EQUIVALENT DURING CYSTALLIZATION

为了解乌桕类可可脂(CTCBE)缓冷结晶横向胀罐爆裂原因,研究CTCBE结晶过程中的膨胀特性,采用流体静力法测试了不同等温结晶条件下CTCBE结晶形成的表观密度和表观体积及其横纵向膨胀状况。结果表明,CTCBE缓冷结晶后形成外部和中部两个晶区。在5-25℃的各等温结晶范围内,当结晶温度增加时,外部结晶区域减小、表观密度变化不大;中部结晶区域增大、表观密度明显减小,CTCBE的表观体积、横向、纵向膨胀率均增大,膨胀横向大于纵向。进一步表明CTCBE在自然缓冷固化的表观体积根本上由其结晶温度决定。为有效防止横向胀罐,自然缓冷固化温度应低于10℃。

In order to explore the expansion characteristics during Chinese Tallow Cocoa Butter Equivalent (CTCBE) crystallization, the apparent density and apparent volume of CTCBE were determined with hydrostatic weighing method after its isothermal crystallization and solidification at different crystallization temperatures. And both the horizontal and vertical dimensions were determined during its expansion. The results showed that the CTCBE would clearly form into two crystal regions, which were the peripheral region and the center region. As the isothermal crystallization temperature was raised during 5-25℃, the apparent density of peripheral region slightly decreased while the density of center region remarkably decreased and the volume ratio of center region increased, and the apparent volume as well as horizontal and vertical expansion rate of the whole CTCBE increased. It was further indicated that the apparent volume of CTCBE was decided by the crystallization temperature. CTCBE should be set below 10℃ to avoid the container being bursted during crystallization and solidification.