Sensory quality of ethylene-exposed carrots (Daucus carota L, cv 'Yukon') related to the contents of 6-methoxymellein, terpenes and sugars

Summary

Carrots were analysed for taste and odour and for contents of terpenes, 6-methoxymellein and sugars during 3 weeks storage at 15 degreesC in an atmosphere containing ethylene (1 mu ll(-1)). The ethylene treatment caused an increase in 6-methoxymellein and the conversion of higher amounts of sucrose to fructose and glucose compared to control carrots stored in air. This corresponded to higher sensory scores for bitterness and terpene flavour and a lower score for sweetness, as measured by an expert taste panel. Principal component analysis showed a more expressed bitter taste, earthy flavour, green flavour, terpene flavour and aftertaste in the ethylene-treated carrots. Correlations were found between sweet taste and the content of sucrose (r = 0.91., p <0.005) and between the contents of various terpenes (particularly <gamma>-terpinene, limonene and caryophyllene) and terpene flavour, green flavour, aftertaste and bitter taste (r greater than or equal to0.72, P < 0.05). In the air-stored carrots these off-flavours seemed to be masked by a high sucrose content. (C) 2000 Society of Chemical Industry.