49F-31 |
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C. MORARU1, T.-C. Lee1, D. H. Fleisher2, L. S. Logendra2, A.-J. Both2, and H. W. Janes2. (1) Dept. of Food Science, Rutgers, The State Univ. of New Jersey, Center for Advanced Food Technology, 65 Dudley Rd., New Brunswick, NJ 08901-8520, (2) Dept. of Plant Biology & Pathology, Rutgers, The State Univ. of New Jersey, 20 Ag Extension Way, New Brunswick, NJ 08901-8500 Tomato is a candidate crop for NASA’s manned interplanetary flights. For NASA’s needs, hydroponical growth conditions were optimized to maximize the yield mass at harvest. Disturbances to these parameters may occur, or temporary changes to the environment in critical stages of the crop development may be intentionally performed aiming to improve the growth, yield and quality indexes. The objective of this study was to identify the effect of a 14-day temperature perturbation on the quality of vine-ripened tomatoes grown hydroponically. Tomato plants of ‘Laura’ cultivar were subjected to two day/night temperature perturbation for 14 days, beginning at 10 days after fruit set: a high temperature (HT, 5°C above control) and a low temperature (LT 5°C below control). The controls for this experiment were grown at 23°C day/18°C night. Fruits were harvested at three developmental stages: breaker (B) stage, 3 and 6 days later. The harvested samples were evaluated for total and soluble solids, pH, acidity, color, Bostwick consistency, firmness and lycopene content. This perturbation caused significant changes in selected tomato quality indexes, while others were not affected. The moisture content, soluble solids and L* color index did not vary with the harvesting stage and temperature perturbation level. Significant effects were found for a* and b* color indexes, acidity and texture: at HT fruits were more red/yellow, had higher acidity and were softer. In some cases, notably pH and Bostwick consistency, changes were statistically significant only for the fully-ripe B+6 stage. The results suggest that: 1) this perturbation has minor effects on the fruits processability, but a larger impact on fresh eating, and 2) the perturbation affects components or mechanisms related to ripening. This information is useful for improving the plant biomass production control systems, in order to maximize the quality of hydroponically-grown tomato crops.
Session 49F, Fruit & Vegetable Products: Fresh vegetables
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