The Carotene Content of Tomatoes as Influenced by Various Factors

Abstract

Several thousand tomato fruit were analyzed for carotene. Fruit were included from plants grown in soil and in sand cultures at various locations and under differing environmental conditions. Attempts were made to correlate the carotene content of the fruit with factors such as fruit size, degree of ripeness, mineral nutrient supply of the plant, soil conditions, and variety. Analyses of ripe tomato fruit show a greater concentration of carotene in the stem-end than in the blossom-end. Of several hundred ripe fruit analyzed for carotene, there was little correlation between fruit size and carotene content. Large fruit were only slightly richer in percentage carotene than small fruit. Wide variations in the supply of the macronutrient elements to tomato plants growing in sand cultures produced only slight variations in the carotene content of the fruit even though the variations in nutrient supply greatly affected growth and fruitfulness of the plants. There were indications that increasing supplies of nitrates to the plants resulted in fruit of increasing carotene content, but the magnitude of the variations in carotene was not great. Differences in carotene content were correlated with varietal differences, but the particular varieties reported here did not differ greatly. Ripe fruit produced in the greenhouse, whether in summer or winter, were lower in carotene than fruit produced outside during the summer. Fruit which were picked green and ripened in storage were very much lower in carotene than vine-ripened fruit. From a practical standpoint, this difference seems to be the most important one noted in this report. Ripe fruit obtained from a local market during the winter contained about half as much carotene as might be expected in vine-ripened fruit in the summer.