Effects of Plastic and Alternative Packaging Materials on Blueberry Quality During Short-Term Storage

This study compared polyethylene terephthalate (PET), corrugated cardboard (CB), cardboard with a cellulose lid (CBC), and rice-straw packages with a polylactic acid lid (RPLA) for half-highbush ‘Northblue’ and highbush ‘Draper’ blueberries. Fruits were stored for 7–8 days at 5 ± 1 °C and 40 ± 2% relative humidity to represent short local distribution conditions in Estonia. Packaging treatments influenced postharvest quality, and responses differed between the two cultivars. In ‘Northblue’, PET maintained lower weight loss (2.4%) and higher firmness (0.51 N) than CB (6.8% and 0.35 N), while CBC and RPLA showed intermediate weight loss and firmness. In ‘Draper’, CB resulted in the highest weight loss (10.6%) and a significant decline in total anthocyanin content from 90 to 49 mg 100 g−1 FW, whereas RPLA showed the highest total phenolic content (207 vs. 144 mg 100 g−1 FW in CB) and organic acid content (0.88 g 100 mL−1). RPLA also maintained the highest organic acid content in ‘Northblue’ (0.65 g 100 mL−1). RPLA showed potential for short-term storage under the low-RH conditions tested, although its performance differed between the two cultivars.