Cultivar differences in New Zealand “Kabocha” (buttercup squash, Cucurbita maxima)

Abstract

This research investigates the sensory and compositional differences of six cultivars of buttercup squash (Cucurbita maxima)—'Ajihei’, ‘Delica’, ‘Emiguri’, ‘Kofuki’, ‘Miyako’, and T133'—using a combination of sensory analysis and physical measurements of viscosity and colour (Minolta Chromameter (CR 200) recording L*, a*, b* values) and biochemical measurements of glucose, fructose, maltose, sucrose, starch, and dry matter (DM) content. The results obtained clearly indicate significant differences in all sensory attributes except for sweetness, nutty flavour, and fibres. Similarly all physical properties and chemical measurements except for starch content are significantly different. A principal component analysis of the sensory data shows that the textural attributes are the main source of cultivar differences for these cultivars. DM and starch content are significantly correlated with the principal sensory dimension indicating its importance in influencing most of the sensory properties. The lack of correlation of sugars, and the significant correlation of textural properties with perceived sweetness suggests the influence of squash texture and cell wall properties modifying the perception of sweetness and flavour. Overall ‘Emiguri’ and ‘Delica’ are the most similar squash cultivars. ‘Kofuki’, the most dry and crumbly cultivar, is different from these two cultivars.