• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1673-1681
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• 2013

Five different chopped frozen garlic products samples, three from Chinese and two from Korean origins being commercially available products in Korean market, were used to confirm their pre-pasteurization or pre-irradiation status by screening (direct epifluorescent filter technique/aerobic plate counts, DEFT/APC; electronic nose, E-nose; photostimulated luminescence, PSL) and identification (thermoluminescence, TL; electron spin resonance, ESR) techniques. Some parts of samples were gamma-irradiated at 1 kGy to be used as control samples in irradiation history identification. DEFT/APC and e-nose successfully showed distinct results between the domestic and imported samples. The PSL photon counts of all the unknown samples were less than 700 (negative), while most of 1 kGy-irradiated samples gave PSL photon counts more than 5,000 (positive). The domestic unknown samples produced the TL glow peaks after $300^{\circ}C$ or more, whereas the imported samples showed TL peaks at the range of $240{\sim}250^{\circ}C$. A clear TL glow peak was obtained from all irradiated samples at $150{\sim}250^{\circ}C$. The unknown samples of Chinese origin gave radiation-specific cellulose ESR signal that was not shown by domestic samples. A multiple step of applying the physical analytical methods is recommended for the effective identification of irradiation status on chopped frozen garlic products.

• Journal of Food Hygiene and Safety
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• v.3 no.4
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• pp.225-232
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• 1988

To improve the storage method for Kimchi, optimal ripening Kimchi was irradiated with doses of 1,3,5 kGy Co-GO gamma radiation, followed by the microbiological, physicochemical and sensory evaluations during storage at $5^{\circ}C$. 1. Total aerobic count increased in the beginning of storage and then decreased slowly as the number of total lactobacilli (anaerobe) increased. The above total aerobic and lactobacilli were reduced by 1 to 3 log cycles with irradiation and at the 90th day after storage the number of total lactobacilli remained $1.30{\times}10^{8}\;per\;ml$ in3 kGy irradiated group. Irradiation treatment at 3 kGy sterilized coli forms and molds contaminating the sample as the level of $2.0{\times}10^{4}\;per\;ml\;and\;5.4{\times}10^{2}\;per\;ml$, respectively and no apparent growth was observed in both control and 1 kGy irradiated groups after 20 days of storage. The population.of yeast, $3.5{\times}10^{3}\;per\;ml$ initially, in, creased steadily during Kimchi storage and at 90 days of storage the number was shown to be $5.6{\times}10^{4}\;per\;ml\;and\;6.5{\times}10^{2}\;per\;ml$ in control and 3 kGy irradiated groups, respectively. 2. In the physicochemical changes during Kimchi storage, pH, acidity and volatile acid of non-irradiated control at the 45th day after storage were 4.0,0.7% and 0.066%, while those of 3 kGy irradiated group were 4.2, 0.59 and 0.06% at the 90th day of storage, respectively. The reducing sugar content of all stored samples changed inversely total acidity content, indicating irradiation delayed the changes of them. The amount of aseorbic acid decreased gradually with the storage time and irradiation dose increase. Textural parameters of 3 kGy irradiated group were superior to those of other groups at the latter stage of storage. 3. Sensory evaluations showed that 3 kGy irradiation was the optimum dose level to extend tite shelf-life of Kimchi more than two months as compared to control.