Development of natural seasoning powder from daun kesom (Polygonum minus)

Abstract

Kesum was known in Malaysia as herb that being used as additional material on Malay cook. Developing of dried kesum powder can make it easily to store in long period as it is hard to find fresh kesum especially in town. The objective of this study was to determine the best drying method to make kesum powder as it evaluate effect of different drying method on physicochemical and consumer acceptance. Kesum leaves, Pofygonum minus, which was obtained from Pasar Batu Enam, Kuala Terengganu was used in this study. Hot air drying oven, vacuum drying oven and freeze drying was applied in this study. Kesum powder made by freeze drying had the lower moisture content which was 8.45±0.31 %, while vacuum drying method gave the highest moisture content which was 9.69±0.38%. Freeze drying resulted in dried kesum with the lowest moisture is more favorable for longer time storage compared to other treatment. It was found that dried kesum made by freeze drying method resulted lowest water activity value which was 0.41±0.08aw and followed by hot air drying, 0.53±0.0l aw while vacuum drying gave highest aw which was 0.53±0.27aw .There was no significant difference (p<0.05) between hot air and vacuum method but then, both shown significant different (p<0.05) compared to freeze drying method. For the hot air oven time vs temperature analysis, it was found that drying rates of samples were decreased shape when the drying time was increased. For all temperature involved, it can be conclude that higher drying rates occuned in early stage of drying period and its going to constant drying rates for longer drying period as it was reached its equilibrium moisture content. Freeze drying resulted lightest color and it showed significant difference (p<0.05) of "L" value to other drying method while vacuum oven gave darkest color compared to other samples (p<0.05). Freeze had showed highest mean score for all attributes in sensory evaluations compared to hot air and vacuum oven drying treatment. Compared to the fresh kesum as control samples, freeze drying never showed any significant difference while vacuum oven showed significant different (p<0.05) for all attributes.