Nanotech team tackles bio-based antimicrobial packaging

Dr. Yixiang Xu, a food processing/engineering assistant professor with Virginia State University's Agricultural Research Station, will head up the project.

The three-year US Department of Agriculture (USDA) capacity building grant will fund Xu’s work in developing antimicrobial, biodegradable-based food packaging films to advance food safety, environmental and agricultural concerns.

She also will be delving into ways to use nanotechnology to extend the shelf life of perishable food products.

Nanotechnology applicatoins​

Xu explained to FoodProductionDaily.com that nanotechnology involves design, fabrication and manipulation of materials or devices at very small sizes—one to 100 nanometers.

It has been used to improve the structure and function of polymers, introduce nanoparticle-based antimicrobials to boost safety and shelf life of foods, and develop ‘smart packaging’ sensors to perform advanced functions—for example, detecting contaminants in foods or monitoring storage conditions.

As Xu told FPD, nanoparticles of some metals (silver, titanium, magnesium and the like) have been employed as antimicrobials in food packaging, with some success.

“However, public concern over the potential toxicity of these materials makes naturally-occurring antimicrobial agents a preferred alternative for food preservation​,” she said. “Incorporation of natural antimicrobial agents to food packaging will not only promote food safety to benefit consumers but also increase value to agricultural waste​.”

Progress in research​

Xu and colleagues have made notable progress in developing natural antimicrobials. Field work includes developing biodegradable nanocomposites by adding nanoclays into biodegradable polymers (such as starch acetates, polylactide, and chitosan) using either  a melt-compounding or a solvent-casting method.

Researchers also have cultivated starch nanocrystals from six crops (corn, barley, potato, tapioca, chickpea and mungbean starches) to better understand how the different botanic origins affect morphological, structural, and thermal properties of such nanocrystals. The purpose is to explore the potential for commercial production of the nanocrystals.

Xu said the team is in the initial stages of preparing naturally occurring antimicrobial agents, enhanced biodegradable nanocomposite materials and pinpointing their properties for potential food packaging applications.

“We hope that after completing this project, we can provide new knowledge of antimicrobial properties of phenolic compounds from grape pomaces, functional properties of polysaccharide for food  packaging, antimicrobial biodegradable nanocomposite films incorporating phenolic compounds and polysaccharide nanocrystals, and the effectiveness of resultant films on improving safety  and quality of ready-to-eat meat products​,” she said.

Xu also landed a two-year grant for $29,186 from the Virginia Department of Agriculture and Consumer Services. The funding will cover the university’s ongoing work to develop commercial chickpea varieties, and to help the state’s farmers get familiar with the crop.