Sensory and chemical changes in five varieties of carrot (Daucus carota L) in response to mechanical stress at harvest and post-harvest

Summary

Carrots harvested by hand or machine and given additional mechanical stress by shaking in a transport simulator were analysed for taste, flavour and content of sugars, terpenes, 6-methoxymellein and ethanol as well as for ethylene production and respiration. Carrots stressed by shaking had higher ethylene production and respiration, higher content of ethanol and 6-methoxymellein and lower levels of total terpenes, several individual terpenes and sugars. This corresponded to a higher sensory score for ethanol flavour and odour, bitter taste, earthy flavour, terpene flavour, aftertaste and sickeningly sweet taste and a lower score for acidic taste and sweet taste as measured by an expert taste panel. Ethanol content was highly correlated with ethanol flavour and odour and sickeningly sweet taste. Of five varieties tested,'Bolero' 'Panter' and 'Yukon' were most sensitive to mechanical stress, whereas 'Napa' and 'Newburg' were most resistant. Hand-harvested carrots were not significantly different from machine-harvested carrots as regards chemical or sensory variables. Principal component analysis showed only slightly different placing of these samples in the score plot. A digital carrot could monitor the degree of mechanical stress to which the carrots were subjected. (C) 2001 Society of Chemical Industry.