Senduduk (Melastoma malabathricum L.) Extract as a Green-Indicator for Monitoring Shrimp Freshness

摘要

The freshness of shrimp is the main priority for consumers. Nutrition and taste of seafood are directly proportional to its freshness. After seafood spoil, the anaerobic metabolism will produce ammonia compounds. In this article, the senduduk (Melastoma malabathricum L.) extract is used to monitor shrimp freshness. Senduduk has flavonoid compounds in high amount, and it can change its color due to the presence of ammonia. A green indicator is made on Whatman paper immersed in senduduk extract and dried at room temperature. The experiment on ammonia solutions shows that the indicator effectively changes color from red, purple, and gray as an indication of the increase of ammonia gas received by the indicator. The indicator also showed consistent color changes for shrimp tests. To observe the quantitative color change, we compute the color intensity based on the image processing method using ImageJ software.