用六偏磷酸钠预防灰斑的研究

摘要

After liming, in order to prevent generation of lime blast, limed pelts were immediately washed by using sodium hexametaphosphate (SHMP) before fleshing, splitting and weighing. FESEM images of the grain surfaces of the pelts washed with SHMP and their EDS analyses showed that there were almost no calcium salts on the surface of the pelt after the limed pelt was washed with 2% SHMP and 200% water (percentage was based on weight of limed pelt) at 22 ℃ for 30 min. This indicated that SHMP is useful to remove calcium salts from surfaces of limed pelts at room temperature. Additionally, the pH and the hydroxyproline concentration of the washing liquor by using 2% SHMP were very similar to those of the conventional washing liquor. These results suggested that washing limed pelts with SHMP for prevention of lime blast is effective and feasible because it can both remove calcium salts from surfaces of limed pelts to prevent generation of lime blast and keep limed pelts in the normal swelling state, which is beneficial to the following fleshing and splitting.%完成浸灰工序后，先加入六偏磷酸钠（SHMP）水洗灰皮，再对灰皮进行去肉、片皮、称重等操作，以预防灰斑形成。用FESEM和EDS分析SHMP水洗灰皮的表面形貌和元素组成，结果表明当用2.0%SHMP和200%水（以灰皮质量为基准）于22℃水洗灰皮30 min后，灰皮表面已经几乎没有钙盐残留。这说明SHMP能在常温下有效去除灰皮表面的钙盐。另外，用2.0%SHMP水洗灰皮后废液的pH和羟脯氨酸浓度均十分接近常规的水洗废液。由此可见，用SHMP水洗灰皮既能脱除灰皮表面的钙盐、阻止灰斑产生，又能使灰皮保持正常的膨胀状态，利于后续去肉、片皮，是一种有效可行的预防灰斑的方法。