Chemical, physical, sensory, and microbiological changes were monitored during storage of unwrapped and shrink-wrapped fresh sweet corn at lo" and 20°C. Wrapping essentially eliminated moisture loss and resulted in elevated carbon dioxide and decreased oxygen concentrations within packages. These effects, together with refrigeration markedly reduced the changes associated with senscence and post harvest deterioration, and hence resulted in at least a threefold extension in shelf life. The water-saturated atmosphere, however, enhanced microbial growth on shrink-wrapped corn. The initial microbial population was effectively decreased by treating the wrapped corn with 0.5 or 1.0 kGy (Co60) irradiation.

No abstract

A major limitation in the calorimetry of fresh broccoli has been the curvature of the head. Total chlorophyll concentration and visual appearance have thus been the methods of choice for color measurement. Samples from six cultivars selected for obvious visual color differences were presented to an older (Gardner C-4) and a newer (Gardner XL-845) generation calorimeter using both whole head and shaved floret sample presentations. No significant differences were observed in the total chlorophyll concentrations of the cultivars, but distinction was made among the cultivars using the shaved floret presentation for the older model and the whole head presentation for the newer model. Newer generation calorimeters thus provide a rapid nondestructive means of assessing fresh broccoli color.

Survival of Salmonella senftenberg 775W, S. anatum, and S. typhimurium during exposure to currently practiced, as well as abusive, pecan processing and storage conditions was studied. Thermal treatments normally carried out during the processing of pecans are inadequate to consistently destroy salmonellae in highly contaminated inshell nuts. Pecan nut packing tissue was toxic to salmonellae, thus affording some protection against high initial contamination and subsequent survival of the organisms. Examinations of inoculated inshell pecans stored at-18,-7, 5, and 21 C for up to 32 weeks revealed that the extent of survival was inversely correlated to the storage temperature. S. senftenberg 775W and S. anatum were not detectable on inshell nuts after 16 weeks of storage at 21 C. Little decrease in viable population of the three species was noted on inoculated pecan halves stored at-18,-7, and 5 C for 32 weeks. Due to organoleptic quality deterioration in pecan nutmeats at elevated temperatures, sterilization methods other than thermal treatment appear to be required for the elimination of viable salmonellae from pecan nuts.