The Effect of Freezing on the Chemical and Physical Components of Irish Grown Organic and Conventional Tomatoes
Document Type Working Paper
Proceedings from the 6th International Conference on Culinary Arts and Sciences- Global, National, Local Perspectives, Stavanger, Norway. June 2008, p 282-287
Tomato flavour is generally attributed to aroma factors, detected by the nose, and taste factors detected by the tongue. The aim of this study was to examine if there are differences in the flavour of Irish grown organic and conventional tomatoes (cv Amoroso). Three batches of organic tomatoes and three batches of conventional tomatoes were tested, using chemical and sensory analysis, each month for three months (July, August and September) during the growing season. GC-MS (n=6 each month) volatiles, pH (n=9 each month) values, and sensory analysis scores for aroma and taste (n=42 each month) were recorded. Markers of tomato aroma intensity and acceptability, overall taste acceptability, sweetness and sourness were identified in both organic and conventional tomatoes using GC-MS. Differences between organic and conventional tomatoes were recorded in each of these categories. Acidity values ranged from 4.2 +/- .04 for organic tomatoes to 4.27 +/- .07 for conventional tomatoes. A comparison between both types of tomato found no significant differences within each month for overall aroma acceptability (P>0.05). However a significant difference in taste acceptability was found within the month of August with panellists preferring the conventional tomatoes (p<.001). Panellists found the conventional tomatoes to be significantly sweeter (p<.001) within each of the three months. Application of Principal Component Analysis (PCA) showed a relationship between the chemical compounds and sensory attributes.