A recent report in The Hindu daily talks about an interesting and exciting new development – packaging that substantially extends the shelf-life of fresh chicken and saves a large amount of energy. This packaging has been developed by a team of researchers at the Food Technology Division of the Bhabha Atomic Research Center (BARC), Mumbai headed by Dr Sweetie R Kanatt and is explained in detail in a recent paper published in the Journal of Food Safety.
Fresh chicken is notoriously difficult to preserve and package since it is highly susceptible to microbial spoilage. It has a high lipid content that is prone to oxidation and leads to spoilage by oxidative rancidity. It also has to be kept in frozen storage to prevent it from going bad. The new packaging not only significantly extends shelf-life but also enables fresh chicken to be kept in chilled storage (2 degrees to 4 degrees Celsius) in a conventional refrigerator as against freezing it for preserving it in pristine condition.
The new packaging uses the antimicrobial and antioxidant properties of extracts from fresh mango peel, which is the key ingredient of the new packaging material. The extracts were blended with polyvinyl alcohol (PVA), gelatine and cyclodextrin and made into a 150 micron thick film that was used to pack fresh chicken. The film also exhibited a high degree of puncture resistance that is essential to prevent damage to the package from bones.
Peels from four different grades of mango – Alphonso, Kesar, Langra and Badami – were used in the study. The extracts from the peel content were obtained using different techniques. The best results were obtained from film that contained a 5% blend of Langra peel extract, which exhibited the highest inhibition against staphylococcus aureus and pseudomonas fluorescens (common food microbes). It was also rich in bioactive compounds like phenolics and carotenoids that provide a high degree of antioxidant properties. The phenolic content in the peel was higher than that in the mango pulp.
The new film was used to package fresh minced chicken and studied using meat packaged in normal polyethylene film as reference. Packs were tested for spoilage every three days. The new film kept the chicken fresh without spoilage for up to 12 days whereas meat wrapped in normal polyethylene film spoilt within just three days. It was also found that the new package needed to be stored in just chilled storage at 2 degrees to 4 degrees Celsius (normal chilled storage in a conventional refrigerator) as against frozen storage, which is the current practice.
Film preparation techniques are now being fine-tuned to enable commercialization of the material and the packaging process.
The new film is totally biodegradable
India is one of the largest producers of mangoes and the peel is usually just thrown away. The increase in shelf-life and energy savings due to doing away with freezing and frozen storage should provide significant advantages to packaging of fresh chicken.