Imagine a world where the very things we discard—like agricultural byproducts and natural plant materials—become the solution to our urgent plastic waste crisis. This isn’t a far-off dream, but a rapidly evolving reality, thanks to dedicated researchers worldwide. Leading this innovative charge is a team from the National Institute of Technology (NIT) Rourkela, delving into the hidden potential within the shells and seeds of common fruits.
Under the guidance of Associate Professor Dr. Preetam Sarkar, the Department of Food Process Engineering is transforming materials long dismissed as waste. With ingenuity, agricultural residues are being converted into biodegradable films poised to revolutionize food packaging. The humble seeds of jackfruit, jamun (Indian blueberry), and litchi are now taking center stage.
This groundbreaking work is the result of a collaborative effort by Dr. Santhosh Ravichandran, Rahul Thakur, Bindhu Sravanthi, and Souvik Giri, under Dr. Preetam’s mentorship. What valuable properties do these unassuming kernels hold? We explored this with Dr. Preetam and Dr. Santhosh Ravichandran, whose direct efforts spearheaded this innovation.
Unlocking the Power of Seeds
Plastic’s pervasive presence in the global food industry is undeniable. Synthetic plastics like LDPE, HDPE, and polystyrene are chosen for their durability and flexibility. However, their environmental cost is immense. "These petroleum-derived materials significantly contribute to pollution, taking up to 700 years to decompose. As they break down, they fragment into microplastics and nanoplastics, contaminating ecosystems and raising serious health concerns, including cancer and reproductive issues," Dr. Preetam explains.
In response, Dr. Preetam’s team chose an innovative path: giving new value to agricultural waste. "Key materials selected include starches from the seeds of jackfruit, jamun, and litchi, combined with tamarind kernel polysaccharides (complex carbohydrates)," he shares. These often-overlooked byproducts offer significant promise for creating eco-friendly packaging.
He elaborates, "Jackfruit seeds, typically discarded after consumption, are rich in starch—a natural polymer that, when processed, forms a robust base for biodegradable films. Jamun seeds contribute their unique properties, and litchi seeds, though small, provide a starch-rich component that enhances the strength and flexibility of the resulting packaging." He adds that tamarind kernel polysaccharides provide excellent mechanical strength and barrier qualities.
The scientific approach extends further. To bolster the protective capabilities of these films, Dr. Preetam’s team incorporates nanoparticles—such as zinc oxide, chitosan, and lignin nanoparticles. "Zinc oxide nanoparticles are known for their antimicrobial activity, contributing to food safety. Chitosan nanoparticles also add antimicrobial properties, while lignin nanoparticles introduce antioxidant activity and boost the film’s biological effectiveness," he clarifies. Each of these components introduces a powerful layer of antimicrobial and antioxidant defense, crucial for protecting perishable foods from harmful microbes like Bacillus cereus and Escherichia coli, which can cause foodborne illnesses.
Biodegradable Films for Extended Freshness
Dr. Preetam explains that these films are applied using an innovative dipping technique, which creates a protective emulsion coating on the fruit. Through trials, the team has demonstrated a significant extension of shelf life—for instance, tomatoes coated with the biodegradable film remained fresh for 15 days longer than uncoated ones. Imagine tomatoes, bananas, and sapotas snugly enveloped in these innovative films, their freshness extended by days or even weeks.
Dr. Santhosh shares his personal journey, "I dedicated almost a year to developing films from whole seed powders of jackfruit, jamun, and litchi. Initially, I faced setbacks. However, I was convinced of the seeds’ potential as strong natural materials suitable for composites. This led me to analyze their composition and isolate the primary compounds contributing to their hardness." He continues, "After extracting and casting these compounds, I produced flexible films. To further enhance their properties, I incorporated natural nanofillers derived from byproducts. This significantly improved the films, which performed excellently as coatings for tomatoes, sapota, and bananas."
Remarkably, these eco-friendly films also fully decompose within 60 days. "We conduct biodegradability studies in small cups. During one such study, I found a small plant that started growing in those cups. Once the films degrade, they become nutrients for the soil microbes and plants. That’s precisely the circular economy we aim to achieve," says Santhosh.
But how durable can natural materials be? "This is where human curiosity meets material science, as the films exhibit mechanical strength comparable to conventional plastics like LDPE or polypropylene," Dr. Preetam notes. "As consumers, we become active participants in this movement, supporting innovations that promise a less polluted, more balanced world," he adds.
The shift from conventional plastics to these biodegradable alternatives is more than just an industrial change; it’s a cultural transformation. It aligns with our growing awareness of environmental stewardship. Each film, meticulously engineered yet inspired by nature, challenges our consumerist norms: What if waste isn’t an end, but a powerful new beginning?
So, as you consider the fruits in your hand and the packaging that surrounds them, let curiosity be your guide. What if every seed, every shell, holds the secret to a cleaner planet? What if the next great leap in sustainable innovation is, quite literally, within our grasp?
