The effects of freezing process and frozen storage at isothermal (-7, -15 and -25 degrees C) and non-isothermal (accelerated life testing with step-stress methodology: temperature range from -30 to -5 degrees C) conditions on pumpkin quality were investigated. Storage temperature conditions were selected to embrace the limits practiced in the cold chain. Quality changes, such as texture, colour CIE Lab and vitamin C (ascorbic acid) content, were evaluated for both frozen storage regimes. The freezing process (that included a pre-blanching step) and subsequent frozen storage had significant impacts on all quality parameters analysed. A fractional conversion kinetic model was adequate in colour, texture and vitamin C data fits. The storage temperature effect was successfully described by the Arrhenius law. This study shows that non-isothermal frozen storage has a marked effect on pumpkin quality. (C) 2011 Elsevier Ltd. All rights reserved.