Edible Packaging for Fruit Preservation: Arizona State University Team Combines Nanoencapsulation and Chitosan Coating

One technology uses nanocapsules made from natural plant nutrients to support human nutrition. Another relies on edible coatings to keep perishable foods fresh. What happens when these two approaches converge?

Recently, Hu Qiaobin, a postdoctoral researcher at Arizona State University in the United States, and the team there placed nutrient-encapsulated nanoparticles inside an edible coating for fresh fruit. By drawing on the antibacterial and antioxidant properties of natural plant nutrients, the coating delivered several functions at once.

Fresh fruit remains vulnerable during storage and transport: microbial contamination and oxidation can cause spoilage and nutrient loss.

Conventional preservation methods have not been able to solve these problems. Extending fruit shelf life while protecting nutritional value therefore requires new approaches, which is why green edible coatings have gained traction in recent years.

For human health, certain natural nutrients in plants can deliver antibacterial, antioxidant, cardiovascular and anticancer benefits. Yet many are largely broken down in the gastrointestinal tract before the body can absorb them.

The proposed answer is encapsulation: once placed in nanocapsules, these nutrients can avoid gastrointestinal degradation and be absorbed far more effectively.

In ordinary circumstances, however, people do not take nutritional supplements unless a health concern arises. Could a widely enjoyed food serve as the carrier instead?

To address these issues, the team proposed a two-birds-one-stone strategy: incorporating nutrient-encapsulated nanoparticles into the edible coating of fresh fruit.

In this design, the antibacterial and antioxidant activity of plant nutrients, together with the sustained-release behavior of nanoencapsulation, helps shield fruit from microbial spoilage and delays nutrient breakdown and oxidation. At the same time, the fruit carrying the nutrient nanoparticles remains suitable for broad consumption.

Trans-resveratrol was an essential component of the study. This natural plant compound has antioxidant and antibacterial activity and is widely regarded as health-promoting. Its low solubility and stability, however, have restricted its use.

The team used nanoencapsulation to enclose trans-resveratrol in nanoparticles. This markedly improved its solubility and stability, and bioavailability rose as a result.

Chitosan, a natural polymer, can be blended with nanoparticles to create an edible film. This film offers strong antibacterial, preservation and nutrient-retention performance: it inhibits microbial growth, reduces fruit rot and texture changes, helps preserve nutrients, and broadens nanoencapsulation's role in food applications.

In controlled tests, the researchers applied the film to strawberries. The results showed a longer shelf life, better retention of fruit firmness, less weight loss during storage, and controlled release of trans-resveratrol.

After forming a composite with chitosan, trans-resveratrol showed significantly greater antibacterial activity without losing antioxidant capacity. In experiments where rats received the composite orally, its bioavailability was significantly improved.

This type of nanoencapsulation can help safeguard food nutrients such as vitamin C and polyphenolic compounds. By slowing nutrient decomposition and oxidation, it can support healthier, more nutritious food.

The edible film may also be applied to other foods, including biscuits, chocolate and meat, giving them antibacterial, preservation and nutrient-retention functions. That could offer consumers safer, fresher and more beneficial options.

Recently, the related paper titled Development of Multifunctional Nanoencapsulated trans-Resveratrol/Chitosan Nutraceutical Edible Coating for Strawberry Preservation was published in ACS Nano.

The paper lists Hu Qiaobin as first author. Professor Wang Shu and Professor Zhaoyang Fan at Arizona State University in the United States are co-corresponding authors.

Going forward, the team may refine nanoencapsulation and edible-film fabrication to improve performance and stability. They may also test different nanomaterials, additives and process parameters to optimize encapsulation and preservation, while exploring applications in additional product categories.

Because nanomaterials would be used in food, more detailed biosafety assessments are needed to ensure consumer safety. These are expected to cover nanomaterial toxicity and stability as well as long-term effects on consumer health.

Next, they intend to evaluate nanoencapsulation in food health care and nutritional supplementation, and are considering collaboration with the food industry to translate the technology into real products.

Source note: China Packaging Network (pack.cn), original link: http://news.pack.cn/show-379405.html