Degradation of total carotenoids and texture in frozen pumpkins when kept for storage under varying conditions of time and temperature

Abstract

The total carotenoid content and textural properties of pumpkin pieces thermally treated at 55°C, 65°C, 75°C, 85°C and 95°C for different blanch times (3 min, 5 min, and 10 min) and subsequently kept for storage at 0°C, −18°C and −40°C for a period of 80 days were measured. The total carotenoids content increased in the thermally treated pumpkin pieces, the increase being greater at 55°C than at 95°C. Storing the pumpkin pieces caused the total carotenoids content to decrease by 35–40% at 0°C, by 15–20% at −18°C and by 25–30% at −40°C. A low-temperature blanch gave a firmer texture to pumpkin in comparison with high-temperature blanching. The texture of thermally treated pumpkins degraded when kept for storage, the losses being greater at 0°C than at −18°C and −40°C. A split plot analysis was performed to study the effect of the factors on the retention of carotenoids.

• Pumpkins
• total carotenoids
• texture
• freezing temperature
• thermal treatment