Starch-based sensor changes color to indicate moisture in food packaging

Brazilian researchers have developed a biodegradable, starch-based sensor that changes color when moisture enters food packaging. With the addition of cobalt chloride, the sensor changes from blue to pink as moisture levels rise and back to blue as they fall. Consumers and manufacturers could use it to monitor the quality and crispness of foods such as cookies with the naked eye or a cellphone camera, without complex equipment.