Conditioning Cucumbers to Increase Heat Resistance in the EFE System

The ethyiene-forming enzyme system (EFE) in cucumber fruit (Cucumis sativus L. cv. Burpee Hybrid II) developed an increased tolerance to hot water immersions of 30 to 60 min at 45°C and 30 to 50 min at 46°C when conditioned at 32.5 ± 0.5°C in air for 24 hr. Thermodynamic analysis of the heat inactivation of the ethyiene-forming enzyme (EFE) system in conditioned and unconditioned cucumbers showed: Increased D-value in the heat resistant EFE of conditioned cucumbers; larger energies of activations and Q₁₀ for conditioned cucumbers; larger entropy and enthalpy changes in conditioned cucumbers. The EFE system in conditioned cucumbers was in a more ordered state than in control cucumbers which was speculated to be due to the formation of hydrophobic bonds during conditioning thereby increasing the thermostability of the EFE system.     

BLACK CLERGY AND URBAN REGIMES: The Role of Atlanta's Concerned Black Clergy

ABSTRACT: This study examines the involvement of black ministers in urban regimes through a case study of Atlanta's Concerned Black Clergy organization. In the early years of black political leadership, the black clergy were promoters of racial solidarity, oftentimes against the interests of low income residents. With black political leadership secure, the clery emerged as frequent critics of development policies during Andrew Young's years as mayor. More recently, the Concerned Black Clergy have become active regime participants helping to influence policy decisions on behalf of the city's poorer citizens. Through their organizational efforts, the Concerned Black Clergy have become part of the process of regime change in the city.     

Effects of Deaeration and Storage Temperature on Quality of Aseptically Packaged Guava Puree

Deaeration of aseptically packaged guava puree did not benefit either color or flavor stability but did aid in the retention of ascorbic acid during the first 6 months of storage. The reduction of headspace O₂ was greatest in the samples stored at 23°C followed by lesser decreases in samples stored at 10° and - 18°C. Sensory panel scores for color, Hunter color values, dissolved O₂, headspace O₂, and ascorbic acid were highly correlated with each other showing that color changes were related to O₂ consumption and ascorbic destruction.     

Ripeness and Tissue Depth Effects on Heat Inactivation of Papaya Ethylene-Forming Enzyme

Heat inactivation studies were conducted on the ethylene-forming enzyme system (EFE) in papayas of different maturities, and at three tissue depths. D-values showed EFE in the mesocarp and endocarp were more heat sensitive than EFE in the exocarp. Within the mesocarp and endocarp, EFE in ¼ and ½ ripe papayas were more heat labile than in mature green and color break fruits. Ion leakage increased concomitantly with increased mesocarp and endocarp ripeness confirming that papayas ripen differentially from the innermost tissues outwards. Membrane integrity as determined by ion leakage may explain the increase in heat sensitivity of EFE in riper tissues.     

Auxin treatment of pre‐veraison grape (Vitis vinifera L.) berries both delays ripening and increases the synchronicity of sugar accumulation

Background and Aims: Pre‐veraison auxin treatments can delay grape berry ripening, but there is little information about their effects on berry development and wine composition. The aim of this study was to further investigate these effects and explore the practical implications of delaying ripening. Methods and Results: Treatment of pre‐veraison Vitis vinifera L. cv. Shiraz berries with 1‐naphthaleneacetic acid (NAA) significantly delayed ripening as measured by the accumulation of total soluble solids (TSS) and anthocyanins. The onset of the post‐veraison phase of berry size increase was delayed in NAA‐treated fruit, but these fruit were significantly larger than Control fruit at harvest. NAA‐treatments significantly increased the synchronicity of berry sugar accumulation. GC‐MS analysis of wine headspace volatiles showed significant, but largely small, differences in the concentration of 19 compounds. No significant difference in sensory properties was found between replicate small‐scale wine lots made from Control and NAA‐treated fruit. Conclusions: Auxin treatment delayed berry ripening, increased the synchronicity of sugar accumulation between berries, increased berry size and changed the levels of some volatile compounds, but did not affect wine sensory properties. Significance of the Study: We propose that NAA sprays might be used to delay grape berry ripening and increase the synchronicity of sugar accumulation, and therefore ripening, without deleterious effects on wine quality. This may be useful in controlling winery intake and fruit composition.