Influence of cultivar, storage and cooking on the mechanical properties of winter squash (Cucurbita maxima)

Texture profile analysis and rupture tests were carried out on raw and cooked tissues of Delica, CF 2 and CF 4 buttercup squash cultivars and Red Warren pumpkin during storage. The raw tissues of CF 2 were the firmest, exhibiting high tissue strength (high failure force) combined with less rigidity, ie lower modulus of deformability (MOD) and higher compressibility (high strain and deformation at failure). Red Warren had the least firm tissues combined with high rigidity and low compressibility. The firmness of Delica and CF 4 tissues was intermediate. The texture parameters such as MOD, failure force, hardness, gumminess and chewiness measured on raw and cooked tissues of the four cultivars showed no significant differences up to 2 months of storage but then decreased (P < 0.05) between 2 and 3 months of storage. The size of the cells and thickness of the parenchyma cell walls among Delica, CF 2 and CF 4 were similar. The greater size of Red Warren parenchyma cells, larger intercellular spaces and thinner cell walls appear to account for its lower tissue strength compared with the other cultivars.