Optimization of Mixing Hot Springs Clay and Iodine Salt on the Sensory Quality of Salted Egg Using Response Surface Methodology

Abstract

This study aimed to find out the suitable proportion of mixing hot spring clay (from Sikao bay in Sikao district, Trang province) and iodine salt for salting eggs using response surface methodology (RSM) with a central composite design (CCD). The 5 levels of hot springs clay (392.3, 500, 760, 1020 and 1127.7 grams) and the 5 levels of iodine salt (221.3, 300, 490, 680 and 758.7 grams) were selected for the study. The experiment consisting 13 trials set at the median of the two factors (composed of hot spring clay 760 grams with 490 grams of iodine salt) was used in 4 trials. Statistical analysis of the result with Design expert program for the sensory quality in 4 sides (the appearance, smell, taste, and satisfaction) towards albumen and yolk. The study found that hot springs clay was significantly negative (for all the tests) (P<0.05). On the other hand, iodine salt result was significantly positive in all cases (P<0.05). Moreover, the hot springs clay and iodine salt yielded significant collaborative interaction with the appearance of the yolk and the smell satisfaction of albumen (P<0.05). The high amount of hot springs clay resulted in a much more negative effect. In contrast, the high amounts of iodine salt produced positive results in all of the testing. The predicted proper proportion between the two factors which wasthe amounts of 500 grams of hot springs clay and 680 grams of iodine salt was recommended for the best quality of albumen and yolk. The results from physical, chemical and microbiological tests indicated that salted eggs in hot springs clay reached community product standard.