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J.B. Magee

The origins, demise and current status of some common misconceptions about the role of fruit and vegetables in human nutrition are discussed. Most, but not all, of the misconceptions were held by the public. The early widespread belief that tomatoes were poisonous was gradually overcome, and today the tomato is one of the most versatile and widely used foods in the diet. Recent reports suggest that consumption of tomatoes and tomato products has the potential to reduce the risk of certain cancers. Our current awareness of the potential of spinach in nutrition and health evolved from an early misconception that its only important nutritive value was as a source of iron. The connection between foods from the nightshade family and arthritis and the connection of cherries and gout relief are discussed briefly. The misconception that a wide variety of fruit and vegetables was not needed in the human diet was rejected long ago. Today fruit and vegetables are considered essential for their intrinsic nutritive value and for their potential health functionality because of the phytochemicals they contain.

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Harbans L. Bhardwaj and Anwar A. Hamama

. In addition, we also evaluated the ratio of omega-6 to omega-3 fatty acids [linoleic (C18:2) versus linolenic (C18:3) fatty acids] in canola sprouts resulting from considerable importance of this ratio in human nutrition. Materials and Methods Mature

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Harbans L. Bhardwaj and Anwar A. Hamama

Sprouts from seeds of cruciferous plants, such as brussels sprouts, broccoli, and cauliflower (Brassica sp.) are considered desirable for human diets. However, no information is available about sprouts made from seeds of canola (Brassica napus L.), a cruciferous crop that is increasing in acreage in the United States and is considered a source of healthful, edible oil. This study reports contents of aluminum (Al), boron (B), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), sulfur (S), and zinc (Zn) in sprouts made from seeds of four canola cultivars (Banjo, KS 8200, KS 8227, and Virginia) grown at three locations (Orange, Petersburg, and Suffolk) in Virginia during two crop seasons (2001–02 and 2002–03). The contents of protein, oil, P, K, Ca, Mg, S, and Na (expressed as percent on a dry weight basis) in canola sprouts were 27.33, 25.1, 0.61, 0.43, 0.43, 0.31, 0.57, and 0.01, respectively. The contents of B, Cu, Fe, Mn, and Zn (expressed as mg·kg−1) in canola sprouts were 12.35, 5.69, 88.46, 45.44, and 48.98, respectively. Contents of various minerals in canola sprouts were greater than those in sprouts of alfalfa, brussels sprouts, mungbean, and radish reported in the literature. It was concluded that canola sprouts are a potential component of diets for superior human nutrition.

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John S. Caldwell and Marilyn S. Prehm

1 Associate professor, Dept. of Horticulture. 2 Assistant professor, Dept. of Human Nutrition and Foods. We thank Robert Frary, Assistant Director for Research & Measurement, VPI & SU, for Statistical Analysis of Student Evaluations. The

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Juan M. Quintana, Helen C. Harrison, James Nienhuis, Jiwan P. Palta, and Michael A. Grusak

To assess nutritional potential, pod yield, and Ca concentration of pods and foliage were determined for a snap bean population, which included sixty S1 families plus four commercial varieties. The experimental design was an 8 × 8 double lattice, repeated at two locations (Arlington and Hancock, Wis.). Snap beans were planted in June 1993 and machine harvested in August 1993. Calcium analyses were made using an atomic absorption spectrophotometer. Significant differences were detected in pod Ca concentration and yield among the S1 families. Pod size and Ca concentration were inversely correlated (R 2 = 0.88). Distinct differences between the locations were not observed, and higher Ca genotypes remained high regardless of location or pod size. Low correlation (R 2 = 0.21) between pod and leaf Ca concentration was found. Pods of certain genotypes appeared to have the ability to import Ca more efficiently than others, but this factor was not related to yield.

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Jack E. Staub, Philipp W. Simon, and Hugo E. Cuevas

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D. Mark Hodges and Gene E. Lester

The consumption of netted muskmelons (Cucumis melo L. Reticulatus group) has raised health concerns due to pathogenic bacteria attaching to sites on the netted rind inaccessible to sanitation. The purpose of this study was to compare 1) the enzymic and nonenzymic antioxidant capacity between representative cultivars of netted muskmelon and both green- and orange-fleshed honey dew muskmelons during storage for 17 days and 2) levels of non-nutrient phytochemicals between these genotypes in consideration of ultimately substituting netted orange-fleshed with non-netted orange-fleshed muskmelon. Netted muskmelon (`Cruiser'), green-fleshed (`Honey Brew'), and orange-fleshed (`Orange Dew') muskmelons were harvested in Texas at the beginning (21 May) and at the end (11 June) of the production season in 2004. Fruit were analyzed immediately (day 0) or stored simulating retail conditions for 7 or 14 days at 7 °C and 95% ± 2% relative humidity plus 3 days at 21 °C. Both `Orange Dew' and `Honey Brew' non-netted cultivars evinced similar and less lipid peroxidation, and hence postharvest senescence, during the 17-day storage period than the netted muskmelon `Cruiser'. In comparison with `Cruiser', `Orange Dew' generally exhibited higher concentrations of ß-carotene and phenolics and, with few exceptions, higher activities of the antioxidant enzymes ascorbate peroxidase (AsPX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), guaiacol peroxidase (POX), and superoxide dismutase (SOD). Higher AsPX and SOD activities in both `Orange Dew' and `Honey Brew' appear to confer a greater resistance to lipid peroxidation in these muskmelon genotypes than to the netted `Cruiser'. `Orange Dew' also appears to be a healthier food choice not only due to its lack of a netted rind which could potentially harbour human illness-related pathogens, but also that it is superior to both `Cruiser' and `Honey Brew' in overall beta-carotene and phenolic levels.

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Kirk W. Pomper and Michael A. Grusak

Understanding the mechanisms that regulate xylem transport of calcium (Ca) to snap bean (Phaseolus vulgaris L.) pods could allow approaches to increase pod Ca concentration and enhance the nutritional value of edible pods. Using the snap bean cultivars Hystyle and Labrador, which exhibit high and low pod Ca levels, respectively, we wished to determine whether there were differences between the two cultivars in stem xylem-sap Ca concentration and whether any differences in sap Ca concentration were related to differences in whole-plant water uptake or Ca import between the cultivars. Well-watered greenhouse-grown plants were placed in a growth chamber at a constant light intensity for an equilibration period. Pot weight loss was measured to determine whole-plant water use and stem xylem exudate was subsequently collected from the severed base of the shoot at flowering and at two stages of pod development. `Hystyle' displayed an exudate Ca concentration that was 50% higher than `Labrador' during pod development. `Labrador' showed 35% greater total water transport through the stem than `Hystyle'. `Labrador' plants also showed a significantly larger leaf area than `Hystyle' plants. Additional plants were used to determine total, long-term Ca influx. No difference was observed between cultivars in total Ca influx into the aerial portion of the plant. With whole-shoot Ca influx being equivalent and pod transpiration rate identical in the two cultivars, our results suggest that the higher whole-plant water uptake in `Labrador' led to a dilution of Ca concentration in the xylem stream and thus less total Ca was transported to developing pods, relative to that in `Hystyle'. Increased transpiration efficiency, enhanced root uptake of Ca, or reduced Ca sequestration in the xylem pathway of the stem could lead to an enhancement in pod Ca concentration in future cultivars of snap bean.

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Susan C. Miyasaka, Marisa Wall, Don LaBonte, and Alton Arakaki

Twelve sweetpotato (Ipomoea batatas var. batatas) accessions/cultivars/landraces (entries) were evaluated for yield, resistance to pests, and quality in five field trials planted at Pepe`ekeo, Hawai‘i Island, and replicated over time with blocks planted on May and Oct. 2014, Feb. and July 2015, and Jan. 2016. Plots were harvested at 4.5 to 6 months after planting. In the first two field trials, local entries planted were ‘Okinawan’, ‘Mokuau’, and ‘Kona B’, as well as PI 531094, ‘Beauregard’, PI 573309, PI 573330, ‘Darby’, ‘Pelican Processor’, and ‘Picadito’. Yields of ‘Mokuau’ and ‘Kona B’ were low and were replaced in the latter three field trials with ‘Murasaki-29’ and ‘LA 08-21p’ from Louisiana State University (LSU) AgCenter, Baton Rouge. At harvest, storage roots were graded according to State of Hawai‘i standards and marketable yields included grades AA, A, and B. Then, injuries of storage roots due to infestations of sweetpotato weevil (Cylas formicarius elegantulus) in each category were estimated. Finally, sugar concentrations, anthocyanins, and β-carotene contents were measured in storage roots. Marketable fresh weight yields of entries differed significantly, with ‘LA 08-21p’ having the greatest marketable yield. However, ‘LA 08-21p’ also had the greatest incidence of damage due to sweetpotato weevil, perhaps because of its growth habit as a tight cluster of storage roots located close to the soil surface. Entries also had significantly different sugar concentrations (fructose, glucose, sucrose, maltose, and total sugars). Concentrations of sucrose ranged from 25 to 68 mg·g−1 fresh weight and were greater than those of monosaccharides analyzed. ‘Beauregard’ had the highest sucrose concentration and total sugars. Purple-fleshed cultivars Okinawan and LA 08-21p contained total monomeric anthocyanins that ranged from 34 to 37 mg/100 g dry weight. Orange-fleshed cultivars Beauregard and Darby contained β-carotene that ranged from 5485 to 8302 µg/100 g fresh weight. These results provide yields of storage roots, susceptibility to sweetpotato weevils, and amounts of antioxidants in purple- and orange-fleshed sweetpotato cultivars to growers interested in producing new sweetpotato cultivars.

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Michael A. Grusak and Kirk W. Pomper

Understanding the mechanisms that regulate xylem transport of calcium (Ca) to snap bean (Phaseolus vulgaris L.) pods could allow approaches to enhance pod Ca levels, and thereby improve the value of this food source for humans. Pods of greenhouse-grown plants of `Hystyle', `Labrador', `Tendergreen', `Green Crop', `BBL94', and `Gold Crop' were examined for stomatal density and rates of pod transpiration throughout pod development. Among pods ranging from 6 to 14 mm in diameter, Ca concentration and pod stomatal density varied inversely with increasing diameter in all cultivars; Ca concentration for pods of a given diameter also varied among cultivars. To assess the influence of pod stomatal density on pod transpiration, water loss was measured from detached pods of `Hystyle' and `Labrador', which have high and low pod stomatal densities, respectively. Pod transpiration rates were similar for the two cultivars, being ≈15% the rate measured in leaves under equivalent conditions, and comparable to rates of cuticular transpiration measured in leaves with closed stomates. These results suggest that pod stomates have no role, or have only a limited role, in pod transpiration. Pods of `Hystyle' and `Labrador' were placed in enclosures that maintained constant high- or low-humidity environments throughout pod development. For each cultivar, the high-humidity environment led to lower pod Ca concentrations, demonstrating that pod transpiration does have a significant impact on pod Ca accretion. However, `Hystyle' consistently exhibited higher pod Ca concentrations, relative to `Labrador', suggesting that differences in xylem sap Ca concentration may have been responsible for cultivar differences in pod Ca concentration.