Lettuce (Lactuca sativa) production historically has been limited in the southeastern United States because of the risk of early bolting and unacceptable bitterness. Small-scale vegetable growers may be able to include lettuce in their production through selection of bolt tolerant and nonbitter varieties. The objectives of this research were to evaluate earliness, bitterness, vitamin E, ascorbic acid, folate, β-carotene, and lutein content in 17 lettuce varieties. Significant difference were found among varieties for days to harvest (DTH) (47 DTH for `Epic' to 37 DTH for `Big Curly'). Observed DTH in this study was consistently 7 to 10 days less than commercial descriptions of the lettuce varieties, due to the use of transplants. Only `Slobolt' and `Greengo' bolted before reaching marketable size. Panelists found that the bitterness was acceptable for most varieties, but not for `Nancy,' `Big Curly,' and `Slobolt'. Significant differences among varieties were also found in vitamin E, ascorbic acid, folate, β-carotene, and lutein. `Redprize' and `Nevada' were the best varieties overall, while `Salinas 88 Supreme,' `Epic,' `Legacy,' `Big Curly,' `Slobolt,' and `Greengo' were unacceptable.
Amy Simonne, Eric Simonne, Ronald Eitenmiller, and Christine Harris Coker
M. Wang and I.L. Goldman
The importance of folic acid in the human diet has been recognized in recent years by major increases in government recommended allowances. Red beet (Beta vulgaris L.) is an important vegetable source of folic acid, however little is known about the extent of variation for native folic acid content in red beet germplasm. A total of 18 red beet entries, including 11 hybrids (F1) and seven open-pollinated cultivars (OP), were evaluated for free folic acid content (FFAC) in replicated field experiments during 1993 and 1994. Significant differences among entries were detected in all studies. FFAC ranged from 3.3 to 15.2 μg·g-1 on a dry mass basis. A significant entry × year interaction was detected. Changes in rank of entries between years were minimal among F1 hybrids, while the changes in rank among OP cultivars were large. These data demonstrate significant variability among cultivated red beet germplasm sources for FFAC. Entries with high FFAC may be useful for increasing levels of this vitamin in red beet.
P. Perkins-Veazie and J.K. Collins
Small fruit are rich in several types of phytochemicals, vitamins, and minerals. These compounds have health functional properties that may protect humans from cardiovascular disease and certain cancers. Several of these phytochemicals, such as dietary fiber, anthocyanins, and polyphenolics, also contribute to small fruit quality. Other components contribute to appearance and taste. Nonvolatile organic acids contribute to the perceived sourness of small fruit and changes in levels can alter visual color by affecting cellular pH and anthocyanin structure. The soluble sugars glucose, fructose, and sucrose contribute directly to the perceived sweetness of the fruit and provide carbohydrates for other metabolic functions such as phenolic and ascorbic acid synthesis.
Philipp W. Simon
), folate, minerals (especially magnesium and potassium), and dietary fiber that are underconsumed or “shortfall” by Americans; 2) consumption of vegetables and fruits is associated with a reduced risk of certain chronic diseases (especially cardiovascular
Teddy Morelock*, Luke Howard, and J. Brad Murphy
Spinach (Spinacia oleracea L.) is a highly nutritious leafy green vegetable that contains high levels of vitamins A, C, E and folate as well as minerals such as iron and calcium. Spinach is high in carotenoids, specifically lutein and β-carotene. Spinach has also been shown to have high ORAC (oxygen radical absorbency capacity) values and to have a high total flavonoids content (100 mg·kg-1). Leaves were collected from 11 commercial cultivars and 15 advanced breeding lines which were grown at the Univ. of Arkansas vegetable substation near Kibler, Arkansas. Samples were placed in polyethylene bags in ice chests and transported to the Univ. of Arkansas within 2 hours and samples were stored at -20 °C until analysis were performed. Both growing season and genotype had an effect on both ORAC and total phenolics. Over-winter spinach, which is planted in the fall and harvested in the spring, had higher total phenolics as well as higher ORAC than fall-planted fall-harvested spinach. Univ. of Arkansas breeding lines had higher average levels of total phenolics and ORAC than commercial cultivars. These data indicate that it should be possible to breed for higher antioxidant capacity in spinach. In a separate study involving the same cultivars wide variation in lutein content was observed with the cultivars F380 and Fallgreen having the highest levels. Data indicate wide variation in lutein and that breeding for increased lutein content is possible.
J.A. Kirkpatrick, T.E. Morelock, L.R. Howard, and F.J. Dainello
Fresh-market spinach production has risen in the United States in the past few years as well as total value of the crop. Increased crop value may be attributed to more “value added” spinach products being produced and marketed. Public awareness of nutrition is rising due to more information being distributed concerning cancer prevention, antioxidants, and neutraceuticals. Spinach is high in the carotenoids beta-carotene and lutein, a known antioxidant for the prevention of age-related macular degeneration (AMD). It is also high in vitamins A, C, E, and folate, fiber, and the mineral iron. In this respect, spinach producers have an advantage over growers of salad vegetables such as lettuce. While this is an advantage, more innovative “value added” methods of marketing this product to the consumer are needed. A dark-green, semi-savoy spinach type developed at the Univ. of Arkansas was studied to determine shelf-life and storage capabilities of root cut plants in transparent clamshell containers. Plants were held at temperatures ranging from 1 to 6 °C. Leaf turgidity and visual characteristics were rated on a 1 to 5 scale. Acceptable characteristics and shelf-life of spinach stored in clamshell containers were seen up to 14 to 21 days when plants were stored at or near 1 °C. These results indicate that spinach packaged in transparent clamshell containers will maintain an acceptable shelf-life and could be beneficial to fresh market spinach producers.
Bhimanagouda S. Patil, Kevin Crosby, David Byrne, and Kendal Hirschi
lack of nutritional assessment in biofortified foods is the norm rather than the exception. Different carotenoid-enriched foods ( DellaPenna, 2007 ) and crops enriched with other micronutrients such as vitamin E ( Ajjawi and Shintani, 2004 ) and folate
Kevin M. Crosby, Daniel Leskovar, John L. Jifon, and Joseph Masabni
Melons ( Cucumis melo L.) are among the most popular and nutritious fruiting vegetables in the United States, with the lowest cost per pound to the consumer. The high levels of vitamin C, carotenoids, folate, potassium, and superoxide dismutase
requiring an increase in consumption. Spinach is one of the most desirable leafy vegetables due to its high content of β-carotene (provitamin A), lutein, folate, vitamin C, calcium, iron, phosphorus, and potassium. The red color of ‘USDA Red’ comes from
Loutrina Staley, D.G. Mortley, C.K. Bonsi, A. Bovell-Benjamin, and P. Gichuhi
, provitamin A, folate, and protein ( Mosha et al., 1995 ). Animal manures such as PL and hydrolyzed fish fertilizers are relatively less expensive than conventional inorganic fertilizers and readily available (especially PL). Manures are relatively good