Color indicators for vegetable products, such as raw salad, could be useful for monitoring the degree of degradation that these products experience prior to consumption. Commercially packed vegetables and fruits go through a continuous natural degradation during storage, distribution,etc. Yet their ripeness/over-ripeness cannot be detected by general testing methods without opening the packaging to access the product. Incorporation of pH indicators (bromocresol purple or methyl red) into polymeric films (polypropylene resin + calcium hydroxide as a CO2 absorbent) were attached to the inside of sealed vegetable salad packages. The results obtained allow the consumers to detect the freshness of the vegetables without the need to open the package. As vegetables degrade, it produces excessive organic acids and its pH falls.6 Thus, once the pH falls below a given value, it will change the color of the indicator and this will signal that over ripening and quality loss have occurred. The direct incorporation of these additives into films used to package the food products is a color indicating device that could help consumer to determine the quality of food without opening the package.

These indicators are placed inside sealed package and are designed to alert consumers to chemical changes occurring within the product. They are sensitive to specific by-products that originate from deterioration reactions in the food. An approach is developed for a smart packaging that was able to monitor the microbial breakdown of products in the headspace of packaged food . This was done using pH indicators that are sensitive to volatile amines associated with food spoilage. This pH sensitive dye was entrapped within a polymeric matrix, and when the spoilage volatile compounds were released, visible color changes were observed as a response. It illustrates the working of this device for the detection of food spoilage. The results indicated that a fast and sensitive detection of spoilage compounds in packaged food can be achieved by colorimetric methods.

These indicators are placed inside sealed package and are designed to alert consumers to chemical changes occurring within the product. They are sensitive to specific by-products that originate from deterioration reactions in the food. An approach is developed for a smart packaging that was able to monitor the microbial breakdown of products in the headspace of packaged food . This was done using pH indicators that are sensitive to volatile amines associated with food spoilage. This pH sensitive dye was entrapped within a polymeric matrix, and when the spoilage volatile compounds were released, visible color changes were observed as a response. It illustrates the working of this device for the detection of food spoilage. The results indicated that a fast and sensitive detection of spoilage compounds in packaged food can be achieved by colorimetric methods.

On identifying volatile amines as food spoilers, a food package was developed with a food quality indicator disk capable of detecting the level of volatile amines emanating from spoilt foods . On similar lines, Halochromes can also be used for products that liberate organic acid on spoilage. Halochromes like Bromothymol Blue (Yellow to Blue), Magcol YV which turn from Violet to Yellow can be used. When put to the test, a gradual color change was observed in the disk as the food decomposed. Consumers are the ultimate beneficiaries of this technology since they will be alerted to presence of an unsafe product.