Edible coatings to extend shelf life of produce

Researchers have developed a method for extending the shelf life of produce through producing edible coatings made from chitosan and beeswax.

The research, published in Food Materials Research, used the edible coatings, both alone and combined with clove essential oils, to assess their impact on the shelf life of perishable fresh produce, including pointed gourds (parwal) and green chillies. 

Five treatment groups were created: one control group with no coating and four groups with different coatings — chitosan, chitosan with clove essential oil, beeswax, and beeswax with clove essential oil. 

Sensory analysis and weight loss evaluations were conducted over eight days for pointed gourds (with assessments every two days) and over 15 days for green chillies (with assessments every three days).

The results indicated that pointed gourds coated with chitosan and clove essential oil exhibited minimal changes in appearance and the lowest weight loss, increasing only from 0.05 to 0.82%. In contrast, the uncoated control group showed significant weight loss, escalating from 12.71 to 24.72%. Similarly, green chillies coated with chitosan and clove essential oil demonstrated superior preservation — with weight loss ranging from 0.40 to 2.30% — compared to the control group, which showed an increase from 3.26 to15.34%.  

Sensory analysis confirmed that the combined coatings effectively maintained the colour and appearance of the produce. 

The study’s lead researcher, Dr Anjali Verma, said: “Our research highlights the potential of natural, eco-friendly coatings to not only extend the shelf life of perishable produce but also to enhance their safety and nutritional value. The combination of chitosan and clove essential oil, in particular, shows great promise for widespread application in food preservation.”

Access the full findings here. 

Image credit: iStock.com/Deepak Verma