Sartaj Singh Gandhi
7th Grade, Monroe Township Middle School
Monroe Township, NJ
Meat Freshness Monitor
Many people rely on their nose to find out if their food is spoiled. Sartaj developed a meat freshness monitor that measures the ammonia gas produced as meat decomposes. He tested it on chicken, beef, pork and turkey, and showed that each decay at different rates.
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Project Background
That chicken in your fridge has been there for a while, is it safe to eat? “Most people often rely on printed expiration dates or the “smell test” to decide if food is safe to eat,” Sartaj says. Getting it wrong could put someone at risk of food poisoning, or throwing out perfectly good meat. Sartaj was surprised to learn that there were no low-cost, easy ways to determine if meat is fresh. He decided to create a reliable way to monitor meat and determine if it has spoiled.
Tactics and Results
Digging into food science, Sartaj learned that as meat decays, it releases ammonia gas, which goes from eight to 15 parts per million when the meat spoils. He hooked up an ammonia gas sensor to a Raspberry Pi to monitor gas production, and attached it to a 3-D printed specialty container. Then he put different meat samples—turkey, chicken, pork and beef—in the device. He tested each meat type with his meat monitor, collecting 10 samples per day for 10 days. His sensor showed that chicken, turkey, and pork all released ammonia that spiked most on day 6, and that each kind of meat spoiled at a slightly different rate. Sartaj hopes that his monitor could be used in refrigerators at home, and his next goal is to test it on different foods, “such as slices of pizza or a plate of spaghetti.”
Beyond the Project
Sartaj runs cross country. “Often, your stomach is cramping and you’re desperate for water, but you know there is only half a kilometer left,” he says. “Embracing that physical grind allowed me to climb from a rank of 24th to 12th by the end of the season.” During the summer, he attends STEM summer programs for science and medicine, but he also loves to catch up on the latest sci-fi movies. He hopes to become a cardiothoracic surgeon. “Combining surgical precision with the physiology of the heart and lungs offers the ultimate opportunity to save lives.”
