INFLUENCE OF SUBSTRATES AND RIPENESS ON T ASTE AND AROMA OF TOMATOES

The tomato variety 'Blizzard' was planted in a randomized block design in expanded clay aggregates, rock wool, and soil as standard cultivat ion. The objective was to determine the influence of various substrate s and degree of ripeness on some quality components responsible for ta ste and aroma of tomato fruit. Plants in the two substrates were grown in closed recirculated nutrient solutions against the standard with t omato plants directly cultivated in soil under glass-house conditions. The taste of tomatoes can be well expressed by the sugar/acid ratio. Therefore, glucose and fructose among the carbohydrates and citric- an d malic acid for organic acids were analyzed of equally sized fruit fr om the second fruit cluster of each plant, harvested at a) red ripe st age and b) green ripe with storage at 15-degrees-C and 95% rH until re d ripe before analysis. The analysis of the organic acids was by enzym e tests and for the two sugars by HPLC. Statistical analysis of the re sults was conduced by Tukey test at 5% probability. The calculated sug ar/acid ratios were between 6.18 and 8.46 for the three substrates and the two ripening stages. There were no significant differences to fru it grown in soil. Nevertheless, the partial p-values indicated that th e sugar/acid ratio for the factor ripeness has stronger expression tha n for the factor substrates.