Phytochemical nanoencapsulation for nutrient delivery and edible coatings for perishable food preservation are two emerging technologies. Leveraging the strong antimicrobial function of phytochemical nutrients, we propose convergent research to integrate the two technologies by embedding phytochemical-encapsulated nanoparticles in an edible coating on fresh fruits to achieve multiple functions. In particular, we report the study of an edible coating on strawberries that is composited of trans-resveratrol (R)-encapsulated nanoparticles (RNPs) embedded in a chitosan (CS) matrix. The biodegradable and biocompatible RNPs significantly increased the aqueous solubility of R by 150-fold and bioavailability by 3.5-fold after oral administration. Our results demonstrated the abilities of the RNP-embedded CS edible coating to diminish dehydration, prevent nutrient loss, inhibit microbe growth, increase nutraceutical value, preserve strawberry quality, and extend shelf life during storage at both 22 and 4 °C. Such a phytochemical nanoencapsulation-based edible coating is promising for the dual purposes of enhancing nutrient delivery and preserving perishable foods.

Objectives Trans‐resveratrol (R) is a natural polyphenolic compound found in red grapes, mulberries, and other berries. Cell and animal studies indicate that it can improve metabolic health through its anti‐inflammation, anti‐obesity, anti‐oxidant properties. However, the evidence is inconclusive in human studies regarding its effectiveness in improving metabolic health, most likely due to its low aqueous solubility, and trivial bioavailability. The objectives of this study are to encapsulate R into biocompatible and biodegradable nanoparticles (R‐NPs), and measure their characteristics and oral bioavailability in C57BL/6J mice. Methods The R‐NPs were made of soy phosphatidylcholine, vitamin E, Tween 80, and R. Their size, polydispersity index and zeta potential were measured using Zetasizer Pro. R‐NPs were stored in dark at 4°C, 22°C and 37°C, and their physical and chemical stability was measured every day. The physical stability was determined using Zetasizer Pro. The encapsulation efficiency and chemical stability were determined using an Agilent 1290 Infinity II UHPLC system. After oral administration of R‐NPs and free R at R concentration 50 mg/kg body weight in C57BL/6J mice, their oral bioavailability was determined by measuring blood R concentrations using the UHPLC system. Results Nanoencapsulation significantly increased aqueous solubility of R by more than 140 times. The mean particle size of freshly made R‐NPs was around 70 nm. The polydispersity index was less than 0.3. The zeta potential of R‐NPs was around −13 mV. R’s encapsulation efficiency was more than 95%. The size, polydispersity index, zeta potential, and R concentrations of R‐NPs did not change significantly at 4°C, 22°C and 37°C for 3 days. The encapsulation efficiency of R‐NPs remained above 94% after storage for 3 days at three tested temperatures. These data indicated good chemical and physical stability of R‐NPs. As compared to free R, R‐NPs had higher oral bioavailability in C57BL/6J mice. Conclusions Nanoencapsulation increased the aqueous solubility and stability of R, and improved R’s oral bioavailability in mice.

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Objectives Active packaging based on natural phytochemicals is of great importance in food preservation against quality degradation, spoilage, and waste generation, and in food safety against foodborne outbreaks. Epigallocatechin gallate (EGCG), a major green tea catechin, has antioxidant and antimicrobial properties. It is, however, unstable and easily degraded during storage. Nanoencapsulation can overcome this issue. The objective of this project is to make biocompatible EGCG-encapsulated lipid nanoparticles (EGCG-NPs) and determine their anti-bacterial activities using Salmonella enteritidis, Escherichia coli, and Staphylococcus aureus. Methods EGCG-NPs were prepared using soy phosphatidylcholine, α-tocopherol acetate, α-tocopherol nicotinate, surfactant, EGCG by a sonication method. The size and polydispersity index of NPs were measured using Zetasizer Pro. EGCG-NPs were applied on chitosan-soaked nanofiber, and their anti-bacterial activities were determined using Salmonella enteritidis, Escherichia coli, and Staphylococcus aureus. The number of bacteria was determined by counting the colony forming unit formed on the agar plates. Results EGCG encapsulation efficiency was more than 90%. The mean particle size of EGCG-NPs was about 70 nm. Their polydispersity index was less than 0.2. The anti-bacterial activity of EGCG-NPs was more potent in Salmonella enteritidis than it in Escherichia coli, and Staphylococcus aureus. EGCG-NPs killed about 80% of Salmonella enteritidis after 1-hour incubation. Conclusions EGCG-NPs was successfully prepared. EGCG-NPs had potent anti-bacterial activities, especially to Salmonella enteritidis. Funding Sources Arizona State University.