{
  "id": 9429557,
  "title": "Starch-based sensor changes color to indicate moisture in food packaging",
  "url": "https://urgent.news/2026/09/23/starch-based-sensor-changes-color-to-indicate-moisture-in-food",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-23T22:20:08.000Z",
  "source": {
    "name": "Phys.org",
    "slug": "phys-org",
    "url": "https://phys.org/news/2026-09-starch-based-sensor-moisture-food.html"
  },
  "original_language": "en",
  "account": "Scientists in Brazil have created a new type of sensor that can change color inside food packaging to show if moisture is present. This biodegradable, starch-based sensor uses cobalt chloride, which shifts from blue to pink as moisture levels increase and back to blue as they decrease. The researchers from the University of São Paulo tested the sensor on cream crackers, which quickly lose their crispness when exposed to too much moisture. The sensor's color change was shown to accurately reflect changes in moisture levels, and it did so within seconds. The sensor's large surface area allows it to detect different humidity conditions inside the packaging. While the cobalt chloride used in the sensor is currently too toxic for direct contact with food, the researchers are exploring other materials, such as natural pigments from fruits like jabuticaba peel, which also change color with pH variations and offer antioxidant benefits. The goal is to develop a system that can monitor the spoilage process of various foods, including meat.",
  "summary": "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…",
  "key_points": [
    "Starch-based sensor changes color to indicate moisture in food packaging",
    "Cobalt chloride shifts from blue to pink as moisture levels increase",
    "Sensor's large surface area detects different humidity conditions"
  ],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}