Development of ready-to-eat Kanom Jeen

Abstract

Kanom Jeen is a popular rice noodle product however, its storage shelf-life is short at room temperature. Thus, the objective of this study was to develop a process to extend its shelf –life with the acceptable quality. Firstly, the effect of acid (citric acid or lactic acid) during soaking on the physicochemical properties of rice flour was investigated. It was found that amylose, protein, and fat contents and viscosity of rice flour decreased while swelling power and solubility at 75℃ increased after acid treatment. Kanom Jeen prepared from acid - treated rice flour had higher tensile strength and springiness but lower hardness and stickiness than those of control sample. Kanom Jeen prepared from rice flour treated with 2% (w/w) citric acid had the highest whiteness index and overall liking score. Secondly, during steaming and kneading steps, the ratio of gelatinized to ungelatinized rice flour was varied at 15:85, 20:80 and 25:75. It was found that the gelatinized rice ratio at 15:85 gave the highest hardness Kanom Jeen. Next, the effect of adding citric acid (0.25%, w/w) and salt (7%, w/w) in the boiling water during cooking was studied and the results showed that the pH of Kanom Jeen was reduced to 3.88 without affecting the textural characteristics. After that, the sample was kept in PE/AL/PE – laminated pouch with nitrogen gas flushing and heated at 85℃ and 90℃ for 1, 3 and 5 min. The result showed that springiness and tensile strength of samples decreased whereas total aerobic plate count and yeast and moulds in sample were lower than 250 cfu/g and 100 cfu/g, respectively. The Kanom Jeen pasteurized at 90℃ for 3 min could be stored up to 29 days at room temperature.