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The objectives of this study were to examine inactivation kinetics of inoculated Escherichia coli O157:H7, Listeria monocytogenes and Salmonella Poona inoculated onto whole cantaloupe and treated with ClO(2) gas at different concentrations (0.5, 1.0, 1.5, 3.0 and 5.0 mg l(-1)) for different times (0, 2.0, 4.0, 6.0, 8.0 and 10.0 min). The effect of ClO(2) gas on the quality and shelf life of whole cantaloupe was also evaluated during storage at 22 degrees C for 12 days. A 100 microl inoculation of each targeted organism was spotted onto the surface (5 cm(2)) of cantaloupe rind (approximately 8-9 log CFU 5 cm(-2)) separately, air dried (60 min), and then treated with ClO(2) gas at 22 degrees C and 90-95% relative humidity for 10 min. Surviving bacterial populations on cantaloupe surfaces were determined using a membrane transferring method with a non-selective medium followed by a selective medium. The inactivation kinetics of E. coli O157:H7, L. monocytogenes and S. Poona were determined using nonlinear kinetics (Weibull model). A 3 log CFU reduction of E. coli O157:H7, L. monocytogenes and S. Poona were achieved with 5.0 mg l(-1) ClO(2) gas for 5.5, 4.2 and 1.5 min, respectively. A 5l og CFU reduction of S. Poona was achieved with 5.0 and 3.0 mg l(-1) ClO(2) gas for 6 and 8 min, respectively. A 4.6 and 4.3 log reduction was achieved after treatment with 5.0 mg l(-1) ClO(2) gas at 10 min for E. coli O157:H7 and L. monocytogenes, respectively. Treatment with 5.0 mg l(-1) ClO(2) gas significantly (p<0.05) reduced the initial microflora (mesophilic bacteria, psychrotrophic bacteria, and yeasts and molds) on cantaloupe by more than 2 log CFU cm(-2) and kept them significantly (p<0.05) lower than the untreated control during storage at 22 degrees C for 12 days. Treatment with ClO(2) gas did not significantly (p>0.05) affect the color of whole cantaloupe and extended the shelf life to 9 days compared to 3 days for the untreated control, when stored at ambient temperature (22 degrees C). 相似文献
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Yurong Guo Lei Liu Jian Zhao & Yang Bi 《International Journal of Food Science & Technology》2007,42(8):1012-1018
Silicon oxide and sodium silicate were investigated as potential agents for the control of postharvest pink rot in Chinese cantaloupe (cultivar Yujingxing) caused by Trichothecium roseum. In vitro tests showed that sodium silicate, when added to potato dextrose agar, was effective in suppressing the radial growth of the pathogen on the medium, whereas silicon oxide was ineffective. The effectiveness of sodium silicate increased with concentration, and the growth of the fungus was completely inhibited at 100 mm . When melons were dipped in the solutions, both silicon oxide and sodium silicate significantly (P < 0.01) reduced the severity of pink rot of the cantaloupe with lesion diameters reduced by up to fivefold when compared with the controls. Scanning electron microscopy‐energy dispersive X‐ray analysis showed that silicon (Si)‐treated melons had a smoother surface feature and higher Si levels in the epidermis, especially at the stomata and along the junction between the exocarp and mesocarp. Enhanced peroxidase and phenylalanine ammonia lyase activities were observed in sodium‐silicate‐treated melons but not in those treated with silicon oxide. The results indicate that different mechanisms might be involved in sodium silicate and silicon‐oxide‐initiated reduction of postharvest pink rot in Chinese cantaloupe. 相似文献
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Studies were done to determine the survival and recovery of Salmonella enterica serotype Poona from cantaloupe rind as affected by environmental conditions between the time of contamination and analysis. Detection and enumeration of the pathogen as influenced by analytical methods were also investigated. Combinations of preenrichment broth (lactose broth or universal preenrichment broth), enrichment broth (Rappaport–Vassiliadis broth or tetrathionate broth), and selective agar medium (bismuth sulfite agar or xylose lysine desoxycholate agar) for detecting S. Poona on inoculated cantaloupes stored at 4°C for 7 days or 21°C for 3 days were equivalent in performance. The use of nalidixic acid resistance as a marker in S. Poona and nalidixic acid in media used to enhance detection or enumeration of the pathogen by inhibiting background micro-flora in sanitizer efficacy studies, for example, would not adversely affect its survival on or recovery from cantaloupes. Overall, the composition of the carrier (water or 5% horse serum, a high organic matrix) used to prepare inocula did not influence the number of S. Poona recovered from the intact rind surface, wounds in the surface, or the stem scar tissue. Regardless of inoculation site or composition of the carrier, populations on spot inoculated melons stored at 4°C remained constant between 2 and 24 h after inoculation. The pathogen grew within 24 h in wounds of spot- and dip-inoculated cantaloupes stored at 21°C and 37°C. The addition of up to 1.0% Tween 80 to 0.1% peptone used to remove S. Poona from the rind surface did not adversely affect viability and may have enhanced detachment. Consideration of these observations is recommended when developing a method to test the efficacy of sanitizers in killing salmonellae on the rind surface of inoculated cantaloupes and to detect or enumerate salmonellae that may be natural contaminants. 相似文献
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The effects of a waiting period at room temperature ( approximately 22 degrees C) before refrigerating fresh-cut watermelon, cantaloupe and honeydew pieces contaminated with Salmonella on survival of the inoculated pathogen were investigated. Whole cantaloupes, honeydew melons and watermelons were washed with water, and fresh-cut pieces from individual melons were prepared and inoculated with a five strain cocktail of Salmonella at 10(5)cfu/ml. Populations of aerobic mesophilic bacteria, yeast and mold and Pseudomonas spp. were higher for fresh-cut cantaloupe than for fresh-cut watermelon and honeydew immediately after preparation. Populations of Salmonella, aerobic mesophilic bacteria, yeast and mold and Pseudomonas ssp. in fresh-cut melons left at room temperature for up to 5h before refrigeration were significantly (P<0.05) higher than populations in fresh-cut melons stored at 5 degrees C immediately after preparation. Populations of Salmonella recovered in fresh-cut melon after inoculation with the cocktail of Salmonella strains averaged 2 log(10)cfu/g for all three types of melons. Populations in fresh-cut watermelon and honeydew pieces declined by 1 log when stored immediately at 5 degrees C for 12 days, while the populations in fresh-cut cantaloupe did not show significant (P>0.05) changes. Populations of Salmonella in fresh-cut melons stored immediately at 10 degrees C for 12 days increased significantly (P<0.05) from 2.0 to 3.0 log(10)cfu/g in watermelon, 1.9 to 3.0 log(10)cfu/g in honeydew and 2.0 to 3.6 log(10)cfu/g in cantaloupe pieces. Holding freshly prepared, contaminated fresh-cut melon pieces at 22 degrees C for 3h or more prior to refrigerated storage would increase the chances of Salmonella proliferation, especially if the fresh-cut melons were subsequently stored at an abusive temperature. 相似文献
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ABSTRACT: Efficacy of decontamination treatments in reducing endogenous microbial populations on cantaloupe and in extending fresh-cut shelf-life were investigated. Composite rind plug samples were washed with water or solutions of sodium hypochlorite, H2 O2 , commercial detergent formulations containing dodecylbenzene sulfonic acid and phosphoric acid, or trisodium phosphate, and surviving microbial populations determined. Fresh-cut cubes were prepared aseptically from whole melons given similar treatments, and their visual appearance and bacterial population determined during storage at 4 °C. Population reductions on washed rind plugs were < 1 log with water, 1 to 2 logs with washing and sanitizing agents applied individually, and 3 logs with some sequential treatments with H2 O2 . H2 O2 applied at 50 °C was superior to other whole-melon treatments, yielding a fresh-cut shelf-life of > 2 weeks. 相似文献
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The objectives of this study were to determine phenolic content and antioxidant activity of methanolic extracts from different parts of cantaloupe (leaf, stem, skin, seed and flesh). The flesh extract afforded the highest yield (89.6 ± 0.3%) whilst the lowest yield was obtained from the seed (13.7 ± 0.5%) (p < 0.05). The leaf extract showed the highest total phenolic content (26.4 ± 0.3 mg GAE/g extract) and total flavonoid content (69.7 ± 3.37 μg RE/g extract) accompanied with best antioxidant activity through all antioxidant assays (p < 0.05). In addition, the stem extract also exhibited good antioxidant activity. Thus, these results suggest that methanolic extracts of cantaloupe leaf and stem may serve as a potential source of natural antioxidant for food and nutraceutical application. 相似文献
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Comparison of the volatile compositions and flavour properties of cantaloupe,Galia and honeydew muskmelons 总被引:3,自引:0,他引:3
Aroma compounds were extracted from three cultivars of muskmelon (Cucumis melo L.) by solid-phase microextraction and analysed by gas chromatography–mass spectrometry. Sulfur-containing esters and compounds containing a straight six-carbon chain were present at high concentrations in cantaloupe melons. Compounds containing a straight nine-carbon chain were at high concentrations in honeydew melons. Methyl esters were present at the highest levels in Galia melons. The sensory properties of the three melons were also compared. Cantaloupe melons were associated with sweet, floral and fruity aromas and a persistent aftertaste. Galia melons possessed the strongest cucumber-like flavours, while cucumber aroma and sweet flavour scored highly in honeydew melons. 相似文献
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Jiraporn Korsrilabut Chaleeda Borompichaichartkul Kiattisak Duangmal 《International Journal of Food Science & Technology》2010,45(7):1524-1531
Effect of partially replacing sucrose with invert sugar on drying kinetics of osmosed cantaloupe was evaluated using four levels of invert sugar (0, 5, 10 and 15% (v/v)) to partially replace sucrose syrup at 50 °Brix. The osmosed samples were then dried at 60 °C. The osmosed cantaloupe without invert sugar exhibited the fastest drying rate. The drying rate decreased with increasing amounts of invert sugar. An increase in the degree of water binding to invert sugar is the most likely explanation for this effect and is supported by the observed decrease in the NMR relaxation time. The use of invert sugar could reduce water activity of final product but not significantly improve overall appearance. Six different mathematical models were tested for their goodness of fit with experimental data. Modified Henderson and Pabis model was found to give the best fit and was able to predict the drying time accurately. 相似文献