Development of biopolymer based colorimetric indicator for monitoring of meat and fish freshness

The need to extend food products' shelf lives is growing as a result of efforts to cut expenses and minimize food waste. The food industry is interested in solutions that would make it easy to keep food fresh and safe for as long as the product is on sale. The purpose of the study is to develop a biopolymer-based colorimetric indicator for monitoring of meat and fish freshness. The significance of the research is to provide food safety via control of the freshness using green and cheap methods. The objects of the study are natural and artificial indicators. The paper presents natural indicators such as curcumin, pomegranate, beetroots, and carrot juice which were incorporated into the compositions of food freshness indicators. The obtained indicators were compared with an artificial indicator, bromothymol blue, and phenol red, concerning their volatile amine monitoring. Additionally, a model of volatile amine release based on the different ammonia solutions was applied in the research. The response of freshness indicators was estimated by the observation of color changes. Compared to the artificial indicators, the curcumin and pomegranate juices gave a similar response. Beetroot and carrot juices did not provide a desirable color change. Further research was made on the development of biopolymer containing freshness indicators based on bromothymol blue and phenol red. The indicators were evaluated for their response to the spoilage of fish and meat samples in the test tubes and in food packaging. Thus, two artificial indicators could be incorporated into effective food freshness indicators for smart packaging.