Quality Evaluation of Blueberries Coated with Chitosan and Sodium Alginate during Postharvest Storage
Edible coatings are used to improve fruits appearance and storage and to extend their shelf-life. The effects of chitosan and sodium alginate as edible coatings on the quality of fresh blueberries during storage were studied. Berries were treated with coatings, packed in polylactic acid punnets and then stored at 0°C for 6 weeks. Fruit quality was evaluated for weight loss, firmness, surface color, titratable acidity, total soluble solids content, total
anthocyanin content, total phenolic content, total antioxidant capacity and yeasts and molds count. Sodium alginate coated samples showed higher values of firmness and lightness during storage, but lower values of total soluble solids content and titratable acidity compared to the other samples. Furthermore, sodium alginate coated blueberries showed higher total phenolic content. Unfortunately, the results showed that alginate coating promoted the growth of yeasts and molds at the end of storage period. On the contrary, chitosan coating delayed ripening as indicated by lower respiration rate, higher total soluble solids content and titratable acidity values compared to other treatments. Moreover chitosan coating inhibited the growth of yeasts and molds. For these reasons, chitosan coating could be considered for commercial application in extending shelf life and maintaining quality of blueberry during storage and marketing.