Chungnam National University researchers develop an edible biofilm for extending fruit shelf life

With significant improvements in transportation technology, the accessibility of fresh food has considerably increased. However, this progress has been accompanied by escalating concerns about food waste during transportation and storage. Globally, around 17% of food at the retail and consumer levels is wasted, resulting in issues like groundwater contamination, hazardous gas emissions, and the spread of infectious pathogens, all contributing to environmental pollution. In a bid to develop efficient, cost-effective, and eco-friendly food preservation technologies, researchers across the world are studying alternatives for the development of packaging materials. Among these, edible coatings made of naturally occurring polymers have shown particular promise.

These protective coatings can protect fruits from post-harvest degradation by preventing water loss and gas exchange, reducing the need for refrigeration or synthetic preservation, while extending shelf life.

Chitin, a natural polymer derived from the crustacean endoskeleton, is chemically modified to produce chitosan (CS). CS is non-toxic, biodegradable, and has remarkable film-forming abilities. However, certain limitations, including weak barrier and low antimicrobial properties, hinder its potential as a food coating material. To address this limitation, a team of scientists, led by Professor Won Ho Park from Chungnam National University, South Korea, incorporated a polyphenolic compound, gallic acid (GA), to produce a CS-GA conjugate. GA is abundantly available in plants and is well known for its excellent antimicrobial and antioxidant properties.

Elaborating further about their study, Prof. Park says, “We wanted to develop a CS-based biofilm with enhanced food coating properties, and we were hopeful that the incorporation of GA might help in achieving that.” This paper was made available online on September 16, 2024, and will be published in Volume 463 Issue 2 of Food Chemistry on January 15, 2025. In this study, the team reports the synthesis and characterization of a CS-GA conjugate film. They compared it with CS films to assess GA’s enhancement effects and tested its efficacy on stored mini bananas and cherry tomatoes.

They observed that the developed film exhibited enhanced mechanical strength, offering protection against food damage during transportation, and improved antioxidant properties, leading to extended shelf life. It also showed improved antibacterial activity against two types of bacteria, confirming its effectiveness against multiple microbial species and superior UV-blocking capabilities to prevent photo-discoloration and damage. Explaining the findings of the storage test. Prof. Park says, “Many consumers are concerned about remaining coating residues on the fruits. The washability of this conjugate makes it appealing for these consumers. Also, we observed a significant reduction in dehydration, discoloration, and mass loss of the stored fruits when the coating was applied. This indicates shelf life extension and freshness retention.”

Going ahead, this green technology could play a significant role in reducing food waste and also contribute to the United Nations' Sustainability Development Goals of halving the food waste by 2030. Sharing his concluding thoughts, Prof. Park says, “In the past, the primary strategy for addressing food waste reduction-related issues was to gather and dispose off food scraps. However, our research suggests that by enhancing food preservation capabilities using eco-friendly approaches, we may significantly reduce food waste occurring during the distribution process.”

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Reference

DOI: 10.1016/j.foodchem.2024.141322

About the institute
Founded in 1952, Chungnam National University (CNU) is one of the leading public universities in South Korea. This university, located in Daejeon, serves as a leading institution for higher learning and offers a wide range of graduate, post-graduate, and doctoral programs across various disciples. The institute is renowned for its robust academic offerings in multiple disciplines including engineering, medicine, and natural sciences. The institute promotes a dynamic learning environment and is equally committed to community engagement and social responsibilities. CNU hosts research labs and institutions that conduct cutting-edge research in fields of nano-technology, robotics, environmental science, and more. The institution is well-equipped with research centers and libraries, besides boasting student lounges, sports-facilities, dormitories, and more such facilities. CNU is committed to foster a collaborative atmosphere, encouraging international student exchange as well as collaborative research. The institute is renowned for its high level of research output. Scientists from the institute also work with industries and government bodies to apply their research findings to solve real-world problems. CNU provides its students a well-rounded learning environment, making it a leading choice for higher education in Korea.

About the author
Prof. Won Ho Park is a Professor at the Department of Organic Materials Engineering at Chungnam National University. His team focuses on practical applications of various nano/biomaterials, including implantable tissue engineering scaffolds, healthcare-related motion sensors, and smart food packaging materials. His scholarly contributions are substantial, with more than 300 peer-reviewed publications, an h-index of 73, and in excess of 24,000 citations. Prior to joining Chungnam National University, Prof. Park worked at UMass Amherst and North Carolina State University. In a recent development, Prof. Park was recognized as one of the "World's Top 1% Scientists" in a list jointly released by Stanford University and Elsevier.