IASST Scientists have devised a biodegradable packaging film that detects relative humidity in stored food. Scientists at the Institute of Advanced Study in Science and Technology (IASST), led by Prof Devasish Chowdhury of the physical sciences division of IASST and his student Sazzadur Rahman, an INSPIRE senior research fellow, have developed a smart biodegradable biopolymer nanocomposite that can detect relative humidity — an invention that is useful in food packaging – according to a report published on The Hindu Business Line.
Read: August 2022 Issue of Food InfoTech Magazine.
Two biopolymers, guar gum (a variety of beans) and alginate (obtained from brown algae), were blended with carbon dots (nanomaterial) to make a nanocomposite film that was successfully used to detect relative humidity. The smart sensor is based on the fluorescence ‘on-off’ mechanisms against humidity.
The food industry has an increasing need for non-toxic, biodegradable, low-cost, and environment-friendly packaging material to replace petroleum-based material like plastics. Besides, it needs smart and active packaging material to detect and report food quality in real time. Such smart and active packaging systems respond to signals while interacting with the food packaging environment. Perishable packed foods are easily damaged by changes in relative humidity.
The study demonstrates that at different relative humidity conditions, such as 11 %, 33 %, 75.30 %, 84 %, and 97 %, there is a change in the fluorescence of biocomposite films under UV light. The practical feasibility of the biocomposite developed film was tested in real conditions by placing a piece of bread with high humidity conditions wrapped with the developed nanocomposite film.
The nanocomposite film shows a change in fluorescence in the presence of high humidity. Hence, the fabricated nanocomposite film can monitor the packed food’s freshness using just a UV light source. “Smart and active packaging can help consumers select a fresh product without breaking the pack. Such innovative packaging boosts sales and reduces consumers’ time in identifying fresh food products,” said Chowdhury.