This article examines the nutritional quality and human health benefits of melons, specifically, muskmelon or cantaloupe (Cucumis melo L. var. reticulatus Naud.) and honeydew melon (Cucumis melo L. var. inodorus Naud.) types. Melons are naturally low in fat and sodium, have no cholesterol, and provide many essential nutrients such as potassium, in addition to being a rich source of beta-carotene and vitamin C. Although melons are an excellent source of some nutrients, they are low in others, like vitamin E, folic acid, iron, and calcium. Since the U.S. diet is already high in fat and protein content, melons should be included in everyone's diet, along with five to eight servings per day of a variety of other fruit and vegetables, to ensure adequate nutrition, promote individual health, and reduce one's risk of cancer and certain other chronic diseases.
Within the Cucurbitaceae are two genera, Cucumis and Citrullus (muskmelons and watermelon, respectively), with sweet-tasting fruits. Per-capita consumption of these two genera rank melons (11.6 kg) second only to bananas (12.6 kg) as the most-consumed fruit in the United States. Consumption of melons, especially muskmelon and honey dew fruits, is significant from the standpoint of their nutritional benefits to humans. Orange-fleshed melons provide a person with 100% of their daily requirement of vitamins A and C. Melons also are a significant source of nutrients: sugars, dietary fiber, calcium, iron, potassium, and “phytochemicals.” Phytochemicals are compounds not presently recognized as having nutrient value. Thirty-eight known phytochemicals are in melons and have preventive properties in addition to anti-cancer attributes. Use of beta-carotene-rich melons is important in chemopreventive trials. Melon production and genetic factors may affect human health-beneficial nutrient and phytochemical quality attributes.
Zhengnan Yan, Dongxian He, Genhua Niu, Qing Zhou, and Yinghua Qu
plants. Nutritional values of hydroponic lettuce influenced by DLI and light quality. Higher DLI increased anthocyanin and vitamin C contents, and decreased nitrate contents, which were consistent with previous studies ( Gent, 2014 ; He et al., 2019
Jaime Prohens, Adrián Rodríguez-Burruezo, María Dolores Raigón, and Fernando Nuez
accessions with an increased concentration of phenolics as a way to develop new varieties with improved nutritional quality was suggested by Stommel and Whitaker (2003) . These authors studied the concentration of hydroxycinnamic acid conjugates in the fruit
J. Emilio Villarreal, Leonardo Lombardini, and Luis Cisneros-Zevallos
Oral Session 30—Produce Quality, Safety, and Health Properties Moderator: Dennis J. Osborne 21 July 2005, 8:00–9:45 a.m. Room 108
Regina R. Melton and Robert J. Dufault
`Sunny' tomato (Lycopersicon esculentum Mill.) seedlings were pretransplant nutritionally conditioned (PNC) in 1988 and 1989 with factorial combinations of N from 100 to 300 mg·liter-1 and P from 10 to 70 mg·liter-1. In 1988, all conditioned seedlings were exposed to 12 hours of 2C for eight consecutive nights before transplanting. In 1989, half of the conditioned plants were exposed to a low-temperature treatment of 8 days with 12-hour nights at 2C and 12-hour days in a warm greenhouse (19C/26C, night/day). In both years, as N PNC increased to 200 mg·liter-1, seedling growth increased. Increasing P PNC from 10 to 40 mg·liter-1 increased seedling growth, but only in 1988. In both years, P PNC did not affect yields. Low-temperature exposure in 1989 decreased seedling growth in comparison to those held in a warm greenhouse (19C/26C, day/night). In 1988, first harvest yields were not affected by N PNC; however, in 1989, as N increased to 200 mg·liter-1, early yields increased. In 1988, total yields increased wit h N PNC from 100 to 200 mg·liter-1 and in 1989 with N at 50 to 100 mg·liter-1 with no further increases from 100 to 200 mg·liter-1. Low-temperature exposure had no effect on earliness, yield, or quality. A PNC regime combining at least 200 mg N/liter and up to 10 mg P/liter should be used to nutritionally condition `Sunny' tomato seedlings to enhance yield.
Anusuya Rangarajan and John F. Kelly
Over the past few years, studies have been conducted exploring the variability in iron nutritional quality from a tropical vegetable, Amaranthus. In order to confirm previous iron bioavailability data, A. cruentus, A. hypochondriacus and A. tricolor lines were grown at the MSU Horticulture Research Center and then analyzed for total and in vitro bioavailable iron. Leaves were harvested 39 days after transplanting, washed, lyophilized and ground. Total iron levels were determined using atomic absorption spectroscopy and bioavailable iron estimates derived using an in vitro assay simulating gastrointestinal digestion. Among the lines tested, total iron concentrations ranged from 145 to 506 ppm. Bioavailable iron ranged from 44 to 70 ppm. Both the total and bioavailable iron measured were highest in A. tricolor, similar to results of previous years. Total iron values were lower for all of the lines than detected previously, but the range of bioavailable iron was similar to earlier work. Bioavailable iron estimated using the in vitro procedure does not appear to be greatly influenced by fluctuations in total iron content. Amaranth could provide between 44 and 70 mg Fe/100 gm fresh weight, equal to 20-35% of the daily Fe requirement for women, and 40-70% for men. Future experiments will utilize an animal bioassay to verify differences detected in bioavailable iron.
Anusuya Rangarajan, Wanda Chenoweth, John F. Kelly, and Karen Agee
Studies have been underway to evaluate the genetic variation in iron nutritional quality of the green leafy vegetable Amaranthus. Initial screening of 35 lines of amaranth from 12 species indicated wide variation in total iron, and small, but significant, differences in bioavailable iron, as determined by an in vitro assay. To verify if the differences in bioavailable iron detected by the in vitro assay were biologically significant, two lines of amaranth, A. tricolor Ames 5113 and A. hypochondriacus Ames 2171, were evaluated using a hemoglobin repletion assay in rats. Weanling Sprague-Dawley rats were made anemic by feeding an ironfree casein-based diet for 4 weeks. The anemic animals were fed treatment diets in which all Fe was provided by the amaranth lines. Hemoglobin levels were measured at the start and end of the treatment period to determine bioavailability. Although A. tricolor contained a higher concentration of total iron (670 ppm), the bioavailability of this iron to rats was lower than from the A. hypochondnacus line (total Fe = 210 ppm). Similar amounts of either amaranth line added to the diet produced similar changes in hemoglobin, although total iron concentrations were significantly different, confirming results observed with in vitro assays.
M.S.S. Rao, Ajmer S. Bhagsari, and Ali I. Mohamed
110 ORAL SESSION 24 (Abstr. 551–556) Vegetable Crops: Crop Physiology/Nutrition
Jonathan R. Schultheis and Robert J. Dufault
Pretransplant nutritional conditioning (PNC) of transplants during greenhouse production may improve recovery from transplanting stress and enhance earliness and yield of watermelon [Citrullus lanatus (Thumb.) Matsum. & Nakai]. Two greenhouse experiments (Expts. 1 and 2) and field experiments in South Carolina and North Carolina (Expt. 3) were conducted to evaluate N and P PNC effects on watermelon seedling growth and their effects on fruit yield and quality. `Queen of Hearts' triploid and `Crimson Sweet' diploid watermelon seedlings were fertilized with N from calcium nitrate at 25, 75, or 225 mg·liter–1 and P from calcium phosphate at 5, 15, or 45 mg·liter–1. In the greenhouse, most variation in the shoot fresh and dry weights, leaf count, leaf area, transplant height, and root dry weight in `Queen of Hearts' and `Crimson Sweet' was attributed to N. Cultivar interacted with N, affecting all seedling growth variables, but not leaf area in Expt. 2. To a lesser extent, in Expt. 1, but not in Expt. 2, P interacted with cultivar, N, or cultivar × N and affected shoot fresh and dry weights, leaf count and leaf area. In the field, transplant shock increased linearly with N, regardless of cultivar or field location. The effect of PNC on plant growth diminished as the growing season progressed. For both cultivars at both locations, N and P PNC did not affect time to first staminate flower, fruit set, fruit width or length, soluble solids concentration, or yield. Vining at Charleston for both cultivars was 2 days earlier when N was at 75 rather than 25 mg·liter–1, without further change with the high N rate. At Clinton, the first pistillate flower was delayed linearly the higher the N rate for `Crimson Sweet'. At Charleston, hollow heart in the `Queen of Hearts' increased nearly 3 times when N PNC rate was tripled (from 75 or 225 mg·liter–1), while N had no effect on hollow heart in `Crimson Sweet'. In contrast, at Clinton, hollow heart in either cultivar was affected by P PNC, not N. PNC with 25N–5P (in mg·liter–1) can be used to reduce seedling growth and produce a more compact plant for easier handling, yet not reduce fruit quality or yield.