(Blackberry, Blueberry, Cranberry, Raspberry)
Generally based on berry surface Bushberry color. Soluble solids and titratable acidity may also be considered. All berries should be harvested near ripe as eating quality does not improve after harvest.
Bushberry Quality Indices
Appearance (color, size, shape, freedom from defects), firmness, flavor (soluble solids, titratable acidity and flavor volatiles), and nutritional value (Vitamins A & C).
Bushberry Optimum Temperature
0±0.5°C (32±1°F) for blackberry and raspberry (2-5 days); and blueberry (1-2 weeks) 3±1°C (37±2°F) for cranberry (2-4 months)
Optimum Relative Humidity
Rates of Respiration Production
To calculate heat production multiply ml CO2/kg·h by 440 to get Btu/ton/day or by 122 to get kcal/metric ton/day.
Rates of Ethylene Production
0.1-1.0 µl / kg·hr at 5°C (41°F)
Responses to Ethylene
Blackberries and raspberries do not respond to ethylene by stimulation of ripening processes. Blueberries are climacteric fruit and respond to ethylene; but should be harvested near to full ripe as flavor does not improve after harvest. Removal of ethylene from storage air may reduce disease development.
Responses to Controlled Atmospheres (CA)
Modified atmosphere packaging for shipment with 15 to 20% carbon dioxide and 5 to 10% oxygen reduces the growth of Botrytis cinerea (Grey Mold Rot) and other decay causing organisms, and reduces the respiration and softening rates of blueberries, raspberries and blackberries thereby extending postharvest life. Whole pallet covers and consumer packages for containment of the modified atmosphere are commonly used. Prompt cooling should be done before atmosphere modification.