Development of Miang Salad, A Pickled Tea Leaves Product of Thailand

Abstract

Miang is pickled tea leaves (Camellia sinensis var. Assamica) from northern Thailand. While its taste is not well accepted, it has high antioxidant activity. Therefore, this research was aimed to develop miang salad that meets consumer’s preference. In developing this product, three studies were done. Firstly, the quality of miang was investigated. The pH of miang was 4.26±0.01, while the total polyphenol content (TPC) and DPPH radical scavenging activity were 15.14±0.37% (w/w dry basis) and 113,058.54±5,643.17 μmol Trolox/100 g dry basis, respectively. For microbiological properties, the total viable count and yeast and mold count were 2.8x105 CFU/g and 5.0x105 CFU/g. The coliform bacteria was less than 3.0 MPN/g. Secondly, suitable formulation for miang salad was studied. There were 6 formulas developed by using mixture design technique. Three miang salad contents were varied: miang (50-80%), pickled ginger (10-40%), and pickled garlic (10-40%). Sensory evaluation was conducted by using 30 untrained panelists (Mae Fah Luang University students) to evaluate the color, odor, sweetness, sourness, and overall liking of miang salad. The result showed that the best formula consisted of 50% miang, 10% pickled ginger, and 40% pickled garlic had the highest overall liking score of 6.30±1.80. Miang salad from the best formula was pasteurized at 70 oC and 80 oC for 10, 15, and 20 minutes. Pasteurization reduced the number of microbes down to <2.5x101 CFU/g (total viable) and <1.0x100 CFU/g (yeast and mold). However, heat treatment reduced the product’s lightness and antioxidant activity. Higher temperature and longer holding time produced worse effect. At 70 oC, TPC and DPPH radical scavenging activity decreased by 2.31-6.92% and 5.33-16.67%, while at 80 oC decreased by 16.14-22.22% and 41.27-49.66%, respectively. In conclusion, miang salad pasteurized at 70 oC 10 minutes was the chosen product due to its highest overall liking score and considering its microbial count, antioxidant activity, and color.