• Food Science and Preservation
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• v.16 no.3
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• pp.371-375
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• 2009

Electron spin resonance (ESR) spectroscopy was used to detect radiation-induced signals from irradiated spices and ESR parameters were analyzed to define specific signals. Four powdered spices (red pepper, garlic, onion, and black pepper) were irradiated with 0, 1, 5, or 10 kGy at room temperature using a [60Co] gamma-ray irradiator prior to ESR analysis. Radiation-induced triplet signals, including those from the cellulose radical, which are center signals ($g_2=2.00673$) within the range of 3.0455 mT, were observed in all irradiated spice samples. The parameters g-value, center field, and signal range of hyperfine triplet ESR signals were constant in all irradiated samples, being specific for cellulose radicals and thereby distinguishing these signals from those of nonirradiated control samples. High positive correlation coefficients ($R^2=0.8452-0.9854$) were obtained between irradiation doses and corresponding ESR signal intensities. Thus, reliable detection of irradiated dried spices by measurement of ESR cellulose signals was confirmed by parameter analysis for the cellulose radical.

• Journal of Food Hygiene and Safety
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• v.4 no.2
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• pp.119-132
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• 1989

Gamma irradiation as a new physical treatment was applied to comparative investigates with a conventional ethylene oxide fumigant on the microbiological and physicochemical qualities of selected spices and dry vegetables such as powdered red pepper, black pepper, welsh onion, onion, garlic, carrot, korean cabbage and instant ramyon soup. The microorganisms contaminated in the sample, including total viable count, thermophilic bacteria, aerobic spore and fungi counts between the $10^4\;to\;10^6/g$ range. Coliforms were found only in black pepper and welsh onion powder as the $10^2\;to\;10^3/g$ level. A radiation dose of 7 to 10 KGy were sterilized completely to the contaminated microorganisms, while ehthylene oxide (E.O.) fumigation reduced of them to the $10^3/g$ level. An optimum dose of irradiation was less detrimental than E.O. fumigation to the physicochemical properties of the sample. Sensory evaluation after three months of storage at room temperatures showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as E.O. fumigated samples. Comparison gamma irradiation with E.O. gas treatment showed that E.O. treatment was less effective than radiation in cotrolling microbial contamination of spices and vegetables.