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Jinghua Guo, Yan Yan, Lingdi Dong, Yonggang Jiao, Haizheng Xiong, Linqi Shi, Yu Tian, Yubo Yang, and Ainong Shi

Hydroponics has been an increasingly important field of vegetable production. However, a big issue with hydroponics is that certain crops can quickly accumulate high levels of nitrate-N (NO3 ± -N) from the hydroponic system. The objective of this research was to decrease NO3 accumulation and increase the nutritional value and yield of vegetable crops using lettuce and oilseed rape as a model under hydroponic production. In this study, two technologies were applied to leafy vegetable production: 1) using supplementary lighting (blue-violet diode) by manipulating illumination and 2) removing fertilization before harvest for a short term (3 or 5 days), thus providing a practical experiment for improving yield and edible qualities of hydroponic leaf vegetable production. Illumination was applied 4 hours a day (0500–0700 hr and 1700–1900 hr) during good weather, or 12 hours a day during bad weather with insufficient natural light (<2000 lux) during the autumn and winter seasons. Results showed that the lettuce cultivar Ou-Luo and the oilseed rape cultivar Ao-Guan Pakchoi had increased yield (50.0% and 88.3%, respectively), decreased NO3 content (26.3% and 30.8%, respectively), and increased total soluble solids (24.1% and 30.6%, respectively). The 5-day fertilizer-free treatment before harvest resulted in 19.2%, 6.4%, and 16.5% yield increases; and 26.0%, 24.3%, and 47.8% NO3 decreases in oilseed rape cultivar Ao-Guan Pakchoi and lettuce cultivars Da-Su-Sheng and Ou-Luo, respectively.

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Denys J. Charles, Amots Hetzroni, and James E. Simon

Recent developments in electronic odor-sensing technology has opened the opportunity for non-destructive, rapid, and objective assessment of food quality. We have developed an electronic sensor (electronic sniffer) that measures aromatic volatiles that are naturally emitted by fruits and fruit products. The ability of our sniffer to detect contamination in fruit juice was tested using tomato juice as a model system. Tomato juice was extracted from cultivar Rutgers and divided into eight glass jars of 300 g juice each. The jars were divided into two treatments: the control jars contained tomato juice mixed with 0.15% sorbic acid to suppress microbial growth, and the experimental jars contained only tomato juice. All the jars were placed open, on a counter top in the laboratory for 8 days. The juice was tested daily with the electronic sniffer and for pH. The total volatiles in the headspace of the juice was extracted on alternating days via dynamic headspace method using charcoal traps, analyzed by gas chromatography, and confirmed by GC/mass spectometry. The results indicate that the sniffer is able to detect differences between the two treatments 4 days after the tomato juice was exposed to ambient atmosphere. The electronic sniffer output for the control juice showed a monotonous decline, while the output for the experimental juice exhibited a sharp incline after day four. This sensor output correlated well with the total volatiles.

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A.P. Medlicott, J.M.M. Sigrist, and O. Sy

The effects of harvest maturity of mangos (Mangifera indica L.) on storage tinder various low-temperature regimes and the influence of storage on quality development during subsequent ripening at higher temperatures were investigated. The capacity for storage of mango fruit depended on harvest maturity, storage temperature, and the time of harvest within the season. Development of peel and pulp color, soluble solids concentration, pH, and softening in `Amelie', `Tommy Atkins', and `Keitt' mangos occurred progressively during storage for up to 21 days at 12C. Based on the level of ripening change that occurred during 12C storage, immature fruit showed superior storage capacity than fruit harvested at more-advanced stages of physiological maturity. On transfer to ripening temperatures (25C); however, immature fruit failed to develop full ripeness characteristics. Mature and half-mature fruit underwent limited ripening during storage at 12C, the extent of which increased with progressive harvests during the season. Ripening changes during storage for 21 days were less at 8 and 10C than at 12C. Chilling injury, as indicated by inhibition of ripening, was found at all harvest stored at 8C, and in early season harvests stored at 10C. Fruit from mid- and late-season harvests stored better at 10 than at 12C, with no apparent signs of chilling injury. Flavor of mangos ripened after low-temperature storage was less acceptable than of those ripened immediately after harvest. Suggestions are made for maximizing storage potential by controlling harvest maturity and storage temperature for progressive harvests throughout the season.

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Steven A. Sargent, Jeffrey K. Brecht, and Judith J. Zoellner

Internal bruising (IB) caused by handling impacts results in disruption of normal ripening in tomato (Lycopersicon esculentum Mill.) locular gel. It was selected as an injury indicator to investigate the effect of drop height (O, 10, 20, 30 cm) onto an unpadded surface and number of impacts (one or two) for three tomato cultivars. For mature-green (MG) tomatoes, significant incidence of IB (5% to 45%) was found in all cultivars for single drops on opposite sides of fruits from 20 cm; two drops on the same location from 20 cm caused 20% to 30% IB. Breaker-stage (BR) tomatoes were more sensitive to impacts than MG. Single drops from 10 cm on opposite sides of BR fruits caused 15% to 73% IB, depending on cultivar. Two drops on a single location from 10 cm caused 50% to 68% IB. `Sunny' was less susceptible to IB than `Solar Set' or `Cobia' (formerly NVH-4459).

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Dale E. Marshall and Roger C. Brook

The tender skin of bell peppers (Capsicum annuum L.) covers a crisp, fragile flesh that is easily bruised, cracked or crushed. During commercial harvest and postharvest handling operations, bell peppers undergo several transfers, each of which has the potential for causing mechanical injury to the peppers. These mechanical injuries include abrasions, cuts, punctures, and bruises, which affect the market grade and reduce pepper quality and subsequent life. Previous research on handling fresh vegetables and fruits has shown that the instrumented sphere (IS) is a tool that can help identify potentially damaging impacts during harvest and postharvest handling operations. For the study reported, the IS was used to evaluate the damage potential for peppers being hand harvested, and for peppers on a packing line. Studies in the field attempted to duplicate how pickers harvest peppers into pails and then empty them into empty wooden pallet bins. For the packing line evaluated, the diverging roll-sizer had the greatest potential for damage. Adding cushioning to hard surfaces and removing the metal support from under the cross-conveyor would help to reduce pepper damage. Cushioned ramps, and hanging flaps or curtains should be used to help reduce acceleration and drop height between pieces of equipment. All locations should be cushioned where peppers impact a hard surface, and drop height should be limited to 3 inches (8 cm) on a hard surface and 8 inches (20 cm) on a cushioned surface. The speed of all components in the system should be checked and adjusted to achieve full line flow of peppers without causing bruising. Workers must receive instruction on the significance of bruising during the harvest and postharvest operations.

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Michael J. Havey and Farhad Ghavami

onion populations, mapping of important phenotypes, fingerprinting of inbred lines and hybrids, and quality control of seed lots. Table 3. Genetic map positions of single nucleotide polymorphisms (SNPs) and mean allelic frequencies across 14 onion

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Donald J. Merhaut, Lea Corkidi, Maren Mochizuki, Toan Khuong, Julie Newman, Ben Faber, Oleg Daugovish, and Sonya Webb

( SWRCB, 2013 ) to oversee that the state maintains water quality and properly allocates its water sources for beneficial uses. The SWRCB developed nine Regional Water Quality Control Boards (RWQCBs). Each of these agencies is responsible for developing

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Suzanne Stone, George Boyhan, and Cecilia McGregor

and age of seed, rather than genetic variation alone, it is possible that the intracultivar variation detected in days to germination and flowering time are a consequence of the vendors’ seed quality practices. Although quality control is an important

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William Pelletier, Jeffrey K. Brecht, Maria Cecilia do Nascimento Nunes, and Jean-Pierre Émond

unacceptable for shipping according to the cooling facility's quality control managers in California. At this point, the fruit were still acceptable for immediate sale. Upon arrival at the DC in Florida, dense water condensation was observed in the clamshells

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O. Smith-Kayode, S.A.O. Adeyemi, Remi Aribisala, Funke Bogunjoko, and G.N. Elemo

Conventional procedure for producing concentrated orange juice through evaporation often causes thermally induce gelation with difficulties in raising brix to optimum level. The objective of this study was to determine the effects of mixed pectinase treatment on solids extraction, recovery and pulp wash from selected sweet orange fruit cultivars. Enzyme use level, depectinization time were varied and pertinent rheological parameters determined on concentrate samples towards standardising quality control protocols. The enzyme treatment improved juice circulation in the climbing film evaporator and solids content raised to ≥ 60 Brix.