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Gamma irradiation can induce beneficial as well as deleterious impacts on chromosome behavior in crop plants. The cytogenetic changes occurring due to the storage of inbred seeds after gamma irradiation in the somatic and gametic cells of Zea mays L. were investigated in this study. A wide spectrum of chromosomal anomalies was encountered in somatic and gametic cells of maize that are gamma irradiated, stored (aged), and treated with a combination of both of these treatments. Gamma rays and ageing treatments induced a number of chromosomal anomalies independently, but a combination of the 2 treatments suppressed the frequency of chromosomal anomalies considerably in somatic as well as gametic cells of maize. It is evident from our study that the decrease in mitotic index was inversely proportional to the increase in doses in all the sets of gamma rays and ageing treatments. The conclusion drawn from our study is that individual treatment of gamma rays induced the highest percentage of chromosomal abnormalities, followed by the combination treatment of ageing and gamma rays, and the least number of abnormalities were induced by the individual treatment of ageing. Hence, the combination treatment proved to be better in the mechanism of genetic repairing, which is discussed in the present study. [ABSTRACT FROM AUTHOR]

The effects of harvest dates on superficial scald development and postharvest quality in 'Granny Smith' apples (Malus domestica Borkh.) were investigated. Apples were harvested at 15-day intervals during 2 consecutive years (2000-2001) and stored at 0°C with 90% relative humidity for 8 months. At the end of the 8 - month storage period plus an additional 1 week at 20°C the percentage of superficial scald was lower (24.4%) in late harvested (November 15) apples than in apples harvested early (October 15), which was 85.4%. The apples harvested late reached a climacteric maximum quicker than those harvested early. The percentage of weight loss, soluble solids, titratable acidity and flesh firmness varied among the different harvest dates. Delaying harvest achieved an increase in soluble solids percentage. Flesh firmness, titratable acidity and soluble solids remained at acceptable levels regardless of harvest dates and storage durations. Loss of chlorophyll was slower in apples harvested late than in those harvested early. The percentage of decay was lower in fruit harvested early. We conclude that 'Granny Smith' apples could be stored for 8 months with minimal scald incidences (0% to 14.2% depending on storage length) if they are harvested in November in Korkuteli, Antalya ecological conditions. [ABSTRACT FROM AUTHOR]

The death kinetics of Escherichia coli O157:H7, E. coli type 1 and total coliforms after irradiation treatment in minced beef were evaluated to analyze the effect of increasing irradiation doses. Irradiation doses ranging from 0.0 kGy to 1.5 kGy were evaluated for reducing numbers of E. coliduring frozen storage conditions at -18 °C for 30 days. D10 values of E. coli O157:H7, E. coli type 1, and total coliforms were 0.245 kGy, 0.552 kGy and 0.293 kGy, respectively. An irradiation dose of 1.5 kGy was shown to inactivate 105 MPN/g of serotype O157:H7 and 103 MPN/g of E. coli type 1. This inactivation level might be considered safe for the consumption of minced beef. Finally, E. coli type 1 was found to be a suitable indicator for assessing the impact of irradiation on E. coli O157:H7 serotype. There was no significant change in numbers of bacteria during frozen storage. [ABSTRACT FROM AUTHOR]

The kinetics of nonenzymatic browning in citrus juice concentrates (orange, lemon, grapefruit and tangerine) during 8 weeks of storage at 28, 37 and 45 °C were investigated. Browning development was followed by measuring absorbance at 420 nm (A 420 ) and using CIE-Lab color system. Analysis of kinetic data from A 420 values suggested a zero-order reaction for nonenzymatic browning, while changes in L* and b* parameters followed a first-order reaction. Activation energy for nonenzymatic browning determined by A420 values ranged from 17.60 to 35.27 kcal mol-1 , while those for L* and b* parameters were 6.67-28.99 kcal mol-1 and 15.38-34.2 kcal mol-1, respectively. Activation energies were higher in orange (28.99-35.27 kcal mol-1) and tangerine (27.84-33.1 kcal mol-1) juice concentrates than those in grapefruit (6.74-27.81 kcal mol-1) and lemon (6.67-17.6 kcal mol-1) juice concentrates. The lower activation energies determined for grapefruit and lemon juice concentrates indicated that nonenzymatic browning reactions are favored in these samples. [ABSTRACT FROM AUTHOR]