Innovative Integration of Arrayan (Luma apiculata) Extracts in Chitosan Coating for Fresh Strawberry Preservation

Strawberries are a rich source of vitamins and antioxidants, among other nutrients, but they are highly susceptible to mechanical injuries, dehydration, and microbial spoilage, and thus have a limited post-harvest shelf-life. Bioactive edible coatings have been studied to decrease or prevent these damages. In this study, ethanolic extracts of Arrayan (Luma apiculata), a traditional berry from the south of Chile, were used to enrich a chitosan-based edible film and coat fresh strawberries. A long-term storage (10 °C) study was conducted to determine the strawberries' weight loss, microbial stability, fruit firmness impact, and antioxidant activity. Later, a sensory panel was conducted to determine overall consumer acceptance. Our results show that the bioactive coating inhibited the growth of different pathogenic bacteria and spoilage yeast. In the stored strawberries, the weight loss was significantly lower when the bioactive coating was applied, and the samples' firmness did not change significantly over time. Microbial growth in the treated strawberries was also lower than in the control ones. As expected, the antioxidant activity in the coated strawberries was higher because of the Arrayan extract, which has high antioxidant activity. Regarding sensory qualities, the covered strawberries did not show significant differences from the uncoated samples, with an overall acceptance of 7.64 on a 9-point scale. To our knowledge, this is the first time an edible coating enriched with Arrayan extracts has been reported as able to prevent strawberries' decay and spoilage.