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Endogenous levels of tocopherols and ascorbic acid were quantified by high-performance liquid chromatography (HPLC) during fruit ripening of New Mexican-type chile peppers (Capsicum annuum L.). γ-Tocopherol (γ-toc) was present in seeds, while R-tocopherol (R-toc) was present in the pericarp. γ-Tocopherol content reached its maximum concentration in seeds from red, succulent fruit and then declined. R-Tocopherol increased from the green to dry red maturity stages. Cultivars differed for R-toc but not for γ-toc contents. Ascorbic acid content increased after the green mature stage and peaked in red fruit with about 75% moisture content. Ascorbic acid was highest in the cultivars NuMex R Naky and Sandia.

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Individual onion (Allium cepa L.) bulbs were evaluated for pungency by measurement of enzymatically produced pyruvate and by flavor perception. In four separate experiments, pyruvate values were highly and significantly correlated to mean sensory ratings. Correlation coefficients (r) were 0.92, 0.84, 0.95, and 0.79, and regression coefficients (R2) were 0.84, 0.71, 0.91, and 0.62. The high correlations indicate that pyruvate analysis can be used as a reliable selection technique for pungency in onion breeding programs.

The β-carotene and total carotenoid content of either fresh or dried tissue of fruits of a total of 57 cultivars of six Capsicum species were analyzed using high performance liquid chromatography (HPLC). β-Carotene levels in ripe fruit varied from 0 to 166 μg·g-1 fresh weight, and carotenoid levels were from 1 to 896 μg·g-1 in ripe fruit in 1996. The range of values for β-carotene was similar in 1997, but that for total carotenoids was wider (4 to 1173 μg·g-1 fresh weight). Fresh fruit of the cultivars Greenleaf Tabasco, Pulla, Guajillo, NuMex Conquistador, Ring-O-Fire, and Thai Dragon contained greater amounts of β-carotene per 100 g fresh weight than the recommended dietary allowance (RDA) for vitamin A for the average adult. For dried Capsicum entries, New Mexican, aji, pasilla, and ancho types had the highest levels of β-carotene. In 1996, β-carotene levels among the dried Capsicum germplasm ranged from 2 to 739 μg·g-1 dry weight, and carotenoid levels from 111 to 6226 μg·g-1. Values were higher in 1997, ranging from 24 to 1198 μg·g-1 dry weight for β-carotene and from 187 to 10,121 μg·g-1 for total carotenoids. A pasilla type (C. annuum L.) had the highest total carotenoid content among the dried entries in both years.

Calcium (Ca) is a major plant nutrient that affects cell wall and plasma membrane formation and plays a key role in plant growth, biomass production, and function. Ca can be used to decrease fruit decay and increase firmness and shelf life. Different sources and concentrations of foliar-applied Ca were examined for the effects on nutrient concentration and growth of ‘Eksotika II’ papaya (Carica papaya) plants. Papaya seedlings were established in pots and irrigated with a standard nutrient solution in a net house. Four preharvest sprays were applied as foliar applications with three different sources of Ca {calcium chloride [CaCl2], calcium nitrate [Ca(NO3)2], and calcium propionate [Ca(C2H5COO)2]} at four concentrations (0, 60, 120, and 180 mg·L−1). Plant Ca concentration was unaffected by the different Ca sources. However, increased Ca concentration applied to the leaves enhanced plant accumulation of phosphorous and Ca in the plant, but decreased potassium (K) and magnesium (Mg) concentrations in the tissues. Plants that received Ca at 180 mg·L−1 had greater height and diameter than control plants. In a field trial with mature trees, preharvest applications of Ca (0, 4000, and 5400 mg·L−1) in the form of CaCl2 showed that increasing concentrations improved fruit Ca concentration, texture, and flavor; and decreased weight loss, Mg content, and apparent disease incidence of the fruit.