Influence of Gamma Radiation on the Microflora of Cucumber Fruit and Blossoms123

Abstract

10 9 0-3.0 * Control samples usually run in duplicate for each radiation experiment during the season.

Influence of Temperature and Humidity on Microbial, Enzymatic, and Physical Changes of Stored, Pickling Cucumbers1

“…The numbers of microorganisms on an individual cucumber can be estimated by multiplying the counts by 20, the average weight for a single fruit. If allowances are made for season, size, and other variables, the populations of the various microbial groups found initially on the fresh fruit were reasonably comparable to those reported by Etchells et al (14).…”

“…In the past, acid-forming bacteria have been exceedingly difficult to separate from the very high populations of other microbial groups present on the cucumber. An earlier study (14) reported a few thousand per gram of cucumber in comparison to over a thousand times this number for other bacterial groups. The population ratios of the different microbial groups were very similar in this study, and acid-forming bacteria were present in small but significant numbers.…”

“…We have reported (14) high populations of heterogeneous microflora on small (¾/to ainch diameter [about 1.91 to 2.23 cm]) cucumber fruit (182 million/U [1 U = 1 cucumber]) and especially on the attached blossom (476 million/U [1 U = 1 blossom]). The average unit weights were: cucumber, 12.4 g; and cucumber blossom, 0.0275 g. Numerical estimates also were reported for eight microbial groups: total aerobes and spores, total anaerobes and spores, coliform bacteria, acid-forming bacteria, yeasts, and molds (higher fungi).…”

“…These enzymes, particularly pectinase, have been implicated directly as causing softening of commercially brined cucumbers (12). Based on this background (12,14,22), the present study was designed to follow population changes of the above-named eight microbial groups, and activities of the two enzyme systems, on pickling cucumbers from the time of harvest through 6 days of storage at various temperatures and RHs.…”

Microbial ecology of fermenting plant materials

“…Plants harbor a numerous and varied microflora. Although the numbers of lactic acid bacteria on plant materials are highly variable, most investigations have shown that their number is very low, often in the range of 10-1000 cells per g [12][13][14][15][16][17], which represents approx. 0.01-1.0% of the total microbial population.…”