In this context, a breakthrough from the National Institute of Technology (NIT) Rourkela in Odisha, India, offers a glimpse into a smarter, more sustainable future. A team of researchers led by Associate Professor Preetam Sarkar has developed an eco-friendly seafood packaging film made from biodegradable materials like kodo millet starch, gum tragacanth, and beetroot peel extract. But this innovation goes beyond biodegradability—it also helps monitor seafood freshness by detecting changes in pH levels, offering a dual solution to both plastic waste and food spoilage. We spoke with Professor Sarkar to learn more about the science behind the innovation, its real-world applications, and how such developments can contribute to building a more sustainable global food system.

Supertrends: What inspired your team to develop a biodegradable seafood packaging that can also detect freshness?

Prof. Preetam Sarkar: India is ranked as the third-largest producer of fish globally. In addition, India stands as the second-largest producer in aquaculture. Also, India is the fourth-largest exporter of fish and fisheries products worldwide. Coming to shrimp, India is one of the largest producers (3rd largest) of the white leg shrimp (the Vannamei shrimp) globally. For example, in 2024, India’s Vannamei shrimp exports have risen by 1% year-on-year, reaching approximately 565,082 metric tons. In terms of export, India is the leader in the export of the white leg shrimp, especially to the United States. Considering the global position of India in the seafood industry, and the fact that seafoods are easily spoiled due to the contamination by food spoilage microbes, we have been inspired to develop an intelligent food packaging system which is biodegradable and at the same time can also alert the consumer regarding spoilage by the change in color.

Supertrends: Why did you choose kodo millet, gum tragacanth, and beetroot peel extract as the key ingredients? Was sustainability the main driver—or were there functional advantages as well?

Prof. Preetam Sarkar: We selected kodo millet starch as the base biopolymer in this case since millets are an underutilized source of agricultural material and also wanted to explore whether an active/intelligent packaging film can be prepared from such millet starches. In addition, starches are biodegradable and therefore sustainable. Gum tragacanth, another plant-based gum was selected to further reinforce the starch-base and provide material strength to the films. Beetroot peel extract was selected since it is a great source of betalains. Betalains are a group of water-soluble plant pigments known for their vibrant colors and potent antioxidant properties. Betalains are gaining interest in the development of intelligent food packaging due to their color-changing behavior in response to pH changes, which can serve as indicators of food freshness or spoilage.

Supertrends: How does your solution compare with traditional plastic or freshness-monitoring alternatives currently used in the food industry?

Prof. Preetam Sarkar: As of now, most pH-responsive packaging films are in the research and development phase, with limited commercial availability. However, the growing interest in sustainable and intelligent packaging solutions suggests that such products may become more accessible in the near future.

Supertrends: Can you walk us through how the pH-sensing mechanism works and how color changes signal spoilage?

Prof. Preetam Sarkar: In order to detect seafood spoilage, our intelligent food packaging films were developed. To impart the spoilage detection ability, the beetroot peel extract was selected. Beetroot peel extract contains a class of molecule known as betalains. Betalains are a class of water-soluble nitrogen-containing pigments found in plants, most notably in beets (Beta vulgaris), and are responsible for the red and yellow colors of many fruits and vegetables. Betalains contains two classes of compounds: (i) Betacyanin and (ii) Betaxanthin. Structurally, betacyanins are formed as ammonium conjugates resulting from the condensation of betalamic acid with cyclo-DOPA and, in some cases, additional amino acids or amines. Betalains show red-violet color in an acidic medium and changes to yellow color under alkaline conditions. Betalain-rich films serve as intelligent pH indicators, displaying distinct color changes that reflect the freshness of seafoods, as spoilage is typically accompanied by shifts in pH or total volatile basic nitrogen (TVBN) levels. As the seafood spoils and volatile amines and ammonia gases are released, these gases interact with the packaging film, thereby increasing the pH. Once the pH is greater than approximately 9.0, the film starts to change color from red/violet to yellow. When the pH increases to (~pH 6-7), the betalains starts to degrade slowly due to slight deprotonation. When the pH increases to greater than 8.0, rapid degradation of the betalain occurs due to deprotonation which leads to structural changes and breakdown of the conjugated system and hence the color changes. 

Supertrends: What kind of testing has the packaging undergone so far, and what results have stood out to you the most?

Prof. Preetam Sarkar: The intelligent films were characterized using several material science techniques which included physical properties (such as moisture content, water solubility, contact angle), optical properties (such as surface color and UV barrier properties), molecular properties (such as the presence of functional groups using Fourier Transform Infrared Spectroscopy), microstructural properties, mechanical properties, water vapor barrier properties, thermal properties, and functional properties (such as antioxidant activity, color change properties under different pH ranges, ammonia sensitivity, and antimicrobial activity). In addition, the application of the film for the detection of seafood spoilage was monitored by measuring the total volatile basic-nitrogen amounts (TVB-N). 

Supertrends: Is this technology limited to seafood, or could it be adapted for other perishable foods?

Prof. Preetam Sarkar: This technology is applicable to all classes of seafoods since the film detects the formation of volatile amines and ammonia gas. 

Supertrends: How important was environmental impact in the design of this packaging?

Prof. Preetam Sarkar: In our recent work on developing pH-responsive food packaging films using kodo millet starch, gum tragacanth, and beetroot peel extract, environmental impact was a central design consideration from the very beginning. Every component was intentionally chosen for its biodegradability, renewability, and low ecological footprint. Kodo millet starch is not only an underutilized indigenous crop, but also a sustainable starch source that requires fewer inputs compared to conventional crops. Gum tragacanth, a natural plant-derived hydrocolloid, adds functional properties like film-forming ability and moisture resistance while maintaining biodegradability. Perhaps most notably, beetroot peel extract—often discarded as waste—was repurposed as a natural, halochromic dye, embodying principles of waste valorization and circular economy. By using agro-industrial by-products and avoiding synthetic indicators or petroleum-based plastics, this packaging addresses environmental concerns at multiple levels: reducing plastic pollution, minimizing food waste, and promoting resource efficiency. Overall, the packaging was designed not just as a functional freshness indicator for shrimp, but as a holistic, eco-friendly alternative that aligns with global efforts to make the food supply chain more sustainable and responsible.

Supertrends: Could this packaging potentially help address larger issues like food waste or supply chain transparency?

Prof. Preetam Sarkar: By visually indicating the freshness of shrimp through pH-responsive color changes, the film empowers everyone along the supply chain—from processors to retailers to consumers—to make informed decisions about food safety and usability. This real-time feedback reduces the likelihood of prematurely discarding still-edible products or, conversely, consuming spoiled seafood, both of which are common contributors to waste and health risks.

Supertrends: The use of beetroot peel and millet starch is especially interesting—was part of the goal to also support local or agricultural byproducts?

Prof. Preetam Sarkar: India is the world's largest producer of millets, contributing approximately 38.4% of global production. India cultivates a diverse range of millets, including major ones like sorghum (jowar), pearl millet (bajra), and finger millet (ragi), as well as minor millets such as kodo millet, little millet, foxtail millet, barnyard millet, and proso millet. Among these, kodo millet is primarily grown in central and southern states of India. Millets are continuously being incorporated in a variety of diets and foods in India to improve nutrition and target reduction in diabetes. Our goal was to use kodo millet starch and beetroot peel extract from a material science perspective to prepare the intelligent food packaging films. 

Supertrends: You mentioned conversations with seafood companies—how do you see this packaging being used at scale in the near future?

Prof. Preetam Sarkar: Given that seafood is highly perishable and spoilage is often linked to pH changes due to microbial activity, pH-responsive packaging offers a clear visual cue to both suppliers and consumers.At scale, we envision this packaging being integrated into:•Primary wraps for individual fish fillets or shellfish, using films that change color in response to volatile amines (e.g., from trimethylamine) released during spoilage.•Inner liners or smart labels in bulk packaging—these could be low-cost, bio-based indicators attached inside crates or cold storage units.•Retail-ready packaging where the freshness indicator is visible to consumers, promoting transparency and reducing food waste by discouraging premature disposal.

Supertrends: What challenges still need to be solved before this innovation is commercially viable?

Prof. Preetam Sarkar: The water vapor barrier properties and the higher water solubility of the films still needs some improvement to be implemented in real world scenario. 

Supertrends: If commercialized, what impact could this have on the Indian seafood industry—or even globally?

Prof. Preetam Sarkar: If commercialized, pH-responsive packaging films could have a significant impact on the Indian seafood industry and the global market. In India, where seafood is a major export and domestic commodity, these films could drastically reduce post-harvest losses by providing real-time indicators of spoilage, especially in regions with limited cold chain infrastructure. This would not only improve food safety and quality but also enhance compliance with stringent international export standards, potentially reducing shipment rejections and increasing market access. For small-scale fishers and processors, the visual nature of these indicators offers an accessible, low-tech method to ensure freshness, helping them compete more effectively in premium markets. On a global scale, such smart packaging could revolutionize seafood logistics and retail by minimizing food waste, optimizing shelf life, and reinforcing consumer trust through transparency. Additionally, because many of these films are developed using biodegradable and bio-based materials, they align with the growing demand for sustainable and eco-friendly packaging solutions, further amplifying their potential for widespread adoption in the food industry.

Supertrends: What other applications or innovations are you exploring in the space of smart or sustainable food packaging?

Prof. Preetam Sarkar: The focus of our research lab at the Department of Food Process Engineering, National Institute of Technology Rourkela, India is to focus on biopolymers and hydrocolloids from agricultural sources (both main products and byproducts) and convert these materials into sustainable, biodegradable, and intelligent food packaging (such as edible films and coatings)-based systems. In the other direction, we are extensively working on the valorization of agricultural byproducts (for example, tamarind seeds, jackfruit seeds, jamun seeds, litchi seeds) into sustainable food packaging systems for food coating applications. 

Supertrends: What role do you believe universities and research institutions should play in shaping the future of food innovation?

Prof. Preetam Sarkar: Universities and research institute around the globe play major roles in all facets of food development and innovation, including processing, engineering, and packaging. Greater research funding from national and international sources in the area of food packaging is essential to bolster this type of research. In addition, greater research collaborations among different universities are also essential to further food packaging research. This will lead to the creation of highly trained next generation of food scientists and food packaging professionals who can lead the future food innovation.

Supertrends: What kind of collaborators, partners, or support would accelerate your work right now?

Prof. Preetam Sarkar: I can mention a few key areas where collaboration could make a significant difference. These partnerships would not only help advance our research but also ensure its successful transition from lab to large-scale application:

Industry partners (Food & Packaging): Collaboration with seafood exporters, cold chain logistics companies, and packaging manufacturers would help pilot these films in real-world settings, especially for monitoring shrimp freshness. These partners could provide practical insights on scalability, integration with existing systems, and consumer response.

Material scientists & engineers: Working with experts in biopolymer engineering and film processing could help optimize film strength, barrier properties, and shelf stability—key for commercialization and industrial applications.

Regulatory and safety experts: Collaborators familiar with FSSAI, EU, or FDA guidelines could support safety validation, migration testing, and compliance processes, ensuring our packaging meets domestic and export requirements.

Agro-waste suppliers & farmer cooperatives: Partnering with local agro-processors or FPOs that handle beetroot, kodo millet, or tragacanth could ensure a steady, cost-effective, and ethical supply of raw materials, strengthening the sustainability aspect.

Startups or investors in green tech and smart packaging: Financial and strategic backing from green tech incubators, impact investors, or packaging-focused startups would help bridge the gap from lab-scale innovation to market-ready solutions.

Retail & consumer feedback platforms: Collaboration with retailers or consumer research groups would help us understand how end-users perceive and interact with this packaging, guiding both design refinement and messaging.

Supertrends: What message would you share with young researchers and innovators who want to create sustainable tech with real-world impact?

Prof. Preetam Sarkar: For young researchers and innovators aiming to create sustainable technologies with real-world impact, I would share this message: Start with a problem that matters—not just to the scientific community, but to people’s lives, the environment, and society at large. Sustainability is not just about inventing the next cool technology; it’s about solving pressing challenges such as climate change, food security, and waste management. Identify problems that have the potential to positively transform industries, improve lives, and reduce environmental harm. Keep innovating with purpose, and the impact will follow!

Closing Thoughts: Innovation Rooted in Purpose

Professor Preetam Sarkar and his team at NIT Rourkela are not just developing food packaging—they are rethinking how we interact with our food systems, sustainability, and innovation itself. In a world urgently seeking solutions to reduce plastic waste and food loss, their pH-responsive, biodegradable packaging offers a compelling example of how science can meet real-world needs.

By transforming agricultural by-products into intelligent, eco-friendly packaging, this project shows the power of circular design and resource efficiency. Its potential impact stretches far beyond India’s vast seafood industry, offering a scalable, accessible tool that could help improve supply chain transparency, reduce food spoilage, and support local economies worldwide.

As the team looks toward commercialization, collaboration will be key, from industry partners and policymakers to investors and agro-waste suppliers. But at the heart of this innovation lies a message for every aspiring scientist and entrepreneur: solving problems that matter can create ripple effects of impact. This is sustainability, not just in materials, but in mindset. And it’s exactly the kind of thinking the future demands.