The relationship between fruit maturation and accumulation of hydrogen peroxide (H 2 O 2 ), lipid peroxidation, ethylene (C 2 H 4 ) production, antioxidant activity (hydrophilic, lipophilic and total) and the antioxidant enzyme ascorbate peroxidase (APX, EC 1.11.1.11) in fruit pericarp tissue of `Chandler' ( Fragaria × ananassa Duch.) strawberry were measured. `Chandler' fruit pericarp maturation and ripening were accompanied by a decline in H 2 O 2 content early in fruit development followed by a rapid accumulation. An increase in membrane lipid peroxidation (thiobarbituric acid reactive substances, TBARS) coincided with accumulation of H 2 O 2 , which preceded a rise in C 2 H 4 production. In general, antioxidant activity declined as fruit matured and ripened. APX enzyme activity increased by 2-fold and peaked at the pink stage of development and then gradually declined with ripening. H 2 O 2 may serve as a signal molecule to initiate the cascade of oxidative processes during maturation and ripening. APX enzyme activity during maturation and ripening was not substantial and thus, may not have a role in alleviating accumulation of H 2 O 2 and subsequent events related to oxidative senescence in fruit pericarp. To our knowledge, this is the first study to present fractionated antioxidant activities (HAA, LAA and TAA) from strawberry pericarp as assessed by the ABTS∼+ radical cation assay. A fundamental understanding of the mechanisms involved in the senescent related-oxidative changes during strawberry fruit ontogeny in relation to quality and nutrition is discussed.
Lotus ( Nelumbo ) is a highly valued plant with a long history for vegetable, ornamental, and medicinal use. Little information is available on the effects of planting time on performance of lotus, especially when grown in containers. The objectives of this study were to find a suitable planting time and to determine best management practices that are of importance for container lotus production. Effects of planting time and disbudding on plant growth indices in southeast Alabama were evaluated in a container production system for the ornamental lotus, N. nucifera ‘Embolene’. Results indicated that plant growth indices were little influenced by different planting dates in March, but were much influenced by planting dates with a difference over a month between February and May. Plants potted and placed outdoors in March and April performed best, and lotus planted in the greenhouse in February and planted outdoors in February and May performed worst. Flower number was not largely influenced by the planting time, but flowering characteristics, especially the flowering peaks, were different among treatments. Planting lotus outdoors between March and May produced the largest return. Influence of planting time on plant growth indices of lotus appeared to be explained by effects of growth-season climate conditions after planting. Disbudding had no impact on plant height but significantly increased underground fresh weight and the number of propagules. Therefore, disbudding should be considered a best management practice to maximize the yield of rhizomes or propagules. Positive linear, quadratic, or cubic relationships were detected among emerging leaf number, underground fresh biomass, and propagule number. Based on the regression models, the yield of lotus rhizomes or propagules can be predicted by the number of emerging leaves. This research provided a guide for nurseries, researchers, and collectors to select the best time to plant lotus outdoors.
Pectinesterase is present in green tomato fruit and increases several-fold during ripening. Several isoenzymes of pectinesterase can be separated by chromatography of tomato extracts on DEAE-Sephadex A-50. The predominant isoenzyme in most tomato cultivars including Better Boy has been designated PE IV. This isoenzyme accounts for most of the increase in total pectinesterase during ripening of these cultivars. The fruit of some cherry tomato cultivars such as Pixie and Short Red contain some PE IV, but the major isoenzyme is PE III which occurs only in these cultivars. PE III and PE IV were isolated from ripe fruit of Short Red and Better Boy, respectively, to further characterize differences between the isoenzymes. PE III binds more strongly to cation exchangers, indicating that it is more basic than PE IV, The molecular weights were estimated by gel filtration to be 26,900 and 25, 100 for PE III and PE IV, respectively. Polyclonal antibodies were raised against the two enzymes. Cross reactivity of the enzymes with the antibodies indicates that PE III and PE IV are immunologically identical.
The health status of Alabama's population ranks above the national average with respect to the prevalence of poor overall health indicators. Consumer knowledge of the health benefits of consumption of fresh fruit is lacking. The compositional and nutritional qualities of fruit are highly variable among states with different climate, soil, and other environmental conditions. Compositional and nutritional data of fresh fruit that reflect Alabama growing conditions is limited. Commercially fully ripened kiwi fruit ( Actinidia deliciosa cvs. Fitzgerald and Hayward) were compared for fruit quality (pH, TA, °Brix, °Brix/TA, and soluble sugars), and antioxidant properties; Vitamin C (reduced, oxidized, and total), Vitamin C Equivalent Antioxidant Capacity (VCEAC), ferric reducing antioxidant power (FRAP), DPPH radical scavenging activity, total phenolics, and flavonoids. In general, `Fitzgerald' ranked higher in overall fruit quality and antioxidant properties when compared to `Hayward'.
Low-dose gamma-irradiation is becoming increasingly an attractive viable technology for control of food-borne pathogens and extension of shelf life of fruits and vegetables. Typically, gamma-irradiation treatment appears to transiently stimulate ethylene synthesis in tomato, which appears to be stress associated, and dose dependent (Larrigaudie et al., 199l). We have investigated the effects of gamma-irradiation treatment at doses of 0, 0.5, 0.75, and 1.0 kGy, alone and in combination with water-based chemical treatment for improving the storage of tomato maintained at 20 °C and 95% RH for 20 days of storage. Changes in ethylene, ascorbic acid and total antioxidant content, color, total soluble solids and carbohydrate concentration were examined. Our preliminary results indicate that these treatments are effective in reducing ethylene concentration in storage while providing a means of eliminating foodborne pathogens without adversely affecting tomato quality.
Little research is reported on container production of ornamental lotus (Nelumbo nucifera Gaertn.). In this study, fertilization has a critical impact on growth index of lotus `No.7', a numbered clone, in 29 liter (7.5 gallon) containers. Compared to the control treatment (zero fertilization), 1–3 tsp. (4g/tsp.) of 20-10-20 (Pro·Sol) applied every 20 days significantly increased plant height (1.3–1.6 times), fresh biomass (2.4–3.3 times), emerging leaf number (1.9–2.7 times), flower number (2.4–2.7 times), and propagule number (1.3–1.5 times). There was a quadratic response as growth parameters increased with increasing fertilizer rates. Growth indices increased linearly from 0–2 tsp. and then leveled as fertilizer rates reached 3 tsp. No difference was recorded in flower number and plant height for 1–3 tsp. fertilizer treatments. Absorption of nutrition increased with fertilization concentration, an absorption peak value appeared between 13 July and 2 Aug. For 1-3 tsp. treatments, nitrogen is nearly 100% absorbed by lotus every 20 days. However, there is some residue for P and K, especially in 3-tsp. treatment in the earlier and later growth season. Analysis of young leaf tissue indicated that macronutrients N, P, K, and dry mass increased, but Ca decreased with increasing fertilizer rates. In tuber tissue, K, Na, and dry mass increased, while Ca and Fe content decreased. The most efficient rate of fertilizer for 7.5 gallon container production of `No.7' lotus was 2 tsp. per 20 days. Although soluble fertilizer also stimulated proliferation of algae growth in the early growth stage of lotus, this problem dissipated as emerging leaves shaded the water surface.
Lotus ( Nelumbo nucifera Gaertn.) is an underused edible aquatic perennial vegetable currently evaluated as a potential functional food source and promoted in the southeastern United States as a rich source of phytonutrients. There is a paucity of information concerning consumer acceptance and willingness to purchase edible, value-added lotus products in the southeastern United States. The purpose of this exploratory study was to evaluate the potential demand and consumer preference for fresh lotus rhizomes and value-added products namely lotus salad, baked lotus chips, and lotus stir-fry. Results of two taste panels indicated that lotus stir-fry was the most preferred value-added product with 77% of participants strongly liking stir-fry, whereas 92% of the participants were willing to recommend this preparation. Results suggest socioeconomic characteristics such as gender ( P = 0.014), age ( P = 0.005), income ( P = 0.043), education ( P = 0.003), shopping habits ( P = 0.013), and type of meal purchased ( P = 0.004) are the factors affecting consumer choice and willingness to recommend lotus stir-fry. Results provide information on consumer acceptance of fresh lotus rhizomes and value-added products. Findings of this case study will assist in analyzing consumer behavior and development of sustainable niche markets for locally cultivated fresh edible lotus rhizomes.
Abstract The response of strawberry plants in the annual hill plasti-culture system to the use of lightweight nonwoven rowcovers (17g/square meter) during the fall establishment period, winter and early spring was investigated. These fabrics can provide some cold and wind dessication protection and can also increase soil and air temperatures around the plant. The increased temperatures under the cover may simulate increased flower bud formation during the short day induction cycles in the fall and spring. Additionally, the covers may provide a protective environment where leaves remain functional for longer periods and crown and root development may be stimulated. In this study, row covers were installed and removed at various intervals from October through March. In addition to the uncovered control plants, the following row cover timings were imposed: Oct.-Mar., Oct.-Feb., Oct.- Dec., Oct.-Nov., Nov.-Mar., Oct.-Feb., Oct.-Jan., Oct.-Dec., Oct.-Nov., Nov.-Mar., Dec.-Mar., Jan.-Mar., and Feb.-Mar. Treatments were reduced from 8 to 6 in the last year of the study. The weight of marketable berries was affected by year and by treatment. Average performance for the four year period showed the Oct.-Feb. treatment to have the highest yields followed by Oct.-Nov. and Feb.-Mar. The Jan.-Mar. performed worse than the control in terms of both yield and berry size. Average berry weight was improved in the Oct.-Feb. and Oct.-Nov. treatment. Row covers in the best treatment (Oct.-Feb.) improved marketable yield by an average of 35% over the control.
