Active modified atmosphere storage to preserve the quality of 'San Andreas' strawberries harvest at two ripening stages

Abstract This work was carried out to evaluate the effect of fruit ripening stage at harvest (“1/3 ripe” and “3/4 ripe”, respectively with 30% and 75% of red color) and passive modified atmosphere (MA) and active MA (with initial initial low O2 and/or high CO2) on quality of ‘San Andreas’ strawberries, with emphasis on bioactive compounds and metabolites of fermentative metabolism. The treatments evaluated were: control; passive MA [low density polyethylene (LDPE) packaging of 40 µm]; active MA with initial low O2 (1 kPa); active MA with initial high CO2 (30 kPa); and active MA with initial low O2 (1 kPa) and high CO2 (30 kPa). After 14 days of storage (0.5±0.2°C/92±2% RH) followed by two days of shelf life (20±5°C/65±10% RH), fruit weight loss was higher in control fruit. Soluble solids content and titratable acidity were not different between treatments. Fruit harvested “1/3 ripe” were firmer and had less intense red color after storage than fruit harvested “3/4 ripe”. Storage conditions did not affect fruit texture maintenance, but all MA conditions delayed fruit red color evolution, regardless of ripening stage at harvest. Strawberries harvested “1/3 ripe” and stored in active MA with initial high CO2 had lower incidence and severity of decay. In general, total phenolic compounds (TPC) and total antioxidant activity (TAA) were higher in fruit harvested “1/3 ripe”. The metabolites of the fermentative metabolism were higher in fruit harvested “3/4 ripe” and stored in active MA with initial low O2. Fruit harvested “1/3 ripe” had higher values of TPC and TAA and lower incidence of decay after storage. The use of active MA with initial high partial pressure of CO2 preserves the postharvest life of ‘San Andreas’ strawberries, by reducing decay without increasing the metabolites of the fermentative metabolism.