• Food Science and Biotechnology
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• 제18권2호
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• pp.390-395
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• 2009

Red radish seeds were irradiated at doses up to 8 kGy using electron beam (e-beam) and gamma ray ($\gamma$-ray). The seed viability and functional properties (carotenoid, chlorophyll, ascorbic acid, and total phenol) of sprouts grown from these irradiated seeds were evaluated. High germination percentage ($\geq$97%) was observed in seeds irradiated at $\leq$5 kGy, but the yield ratio and sprout length significantly decreased with increased irradiation dose. Irradiation at $\geq$6 kGy resulted in curling of the sprout roots. Sprouting enhanced the functional properties of red radish seeds as indicated by the increased carotenoid, chlorophyll, ascorbic acid, and total phenol contents during germination. However, radiation treatment hampered the growth of seeds resulting in underdeveloped sprouts with decreased carotenoid, chlorophyll, ascorbic acid, and total phenol contents. In general, e-beam and $\gamma$-ray irradiation of red radish seeds showed similar effects on the seed viability and functional properties of sprouts. Postharvest storage reduced the functional quality of sprouts.

• 한국식품위생안전성학회지
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• 제6권3호
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• pp.165-169
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• 1991

염장미역 제품의 염농도 감소와 저장 조건 개선을 위한 연구의 일환으로 감마선 조사가 염장미역의 이화학적 특성에 미치는 영향을 조사한 결과는 다음과 같다. 미역의 chlorophyll과 carotenoid 색소는 감선 조사에 의해 부분적으로 감소되었고 $10^{\circ}C$ 내외의 저장조건에서 6개원 저장시 비조사 시료와 2kGy 조사시료의 색소 잔존률은 서리 유의적인 차이가 없이 chlorophyll이 47~77%, carotenoid가 54~56%였다. 미역의 관능적 품질과 관련된 유기산과 휘발산의 함량은 염농도가 낮고 저장온도가 높을수록 증가하였고, 감마선 조사에 의한 미역의 조직 연화는 알긴산 추출과 관련이 있는 것으로 나타났다.

• 한국축산식품학회지
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• 제24권4호
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• pp.367-372
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• 2004

Nitrite, a curing agent of meat products, is precursors of carcinogenic N-nitrosamines during processing of meat products or under human stomach conditions as well as having its own toxicity. Some researches have been conducted to evaluate the effects of ionizing radiation on the reduction of residual nitrite and N-nitrosamines in an aqueous model system and cured meat products with different packaging methods during storage. These results showed that the gamma irradiation was effective in reducing the residual nitrite and N-nitrosamines in an aqueous model system as well as meat products. Especially, irradiation combined with vacuum or modified atmosphere packaging was more effective in nitrite and N-nitrosamines reduction than aerobic packaging during storage. The objective of this review is to introduce the irradiation technology for the application of reducing the residual nitrite and N-nitrosamine contents in meat products.

• 대한의용생체공학회:의공학회지
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• 제39권4호
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• pp.161-167
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• 2018

Polyvinyl alcohol/sodium carboxymethyl cellulose (PVA/NaCMC) hydrogels were prepared by physical crosslinking (cyclic freezing/thawing) and gamma (${\gamma}$)-ray irradiation to evaluate the effect of NaCMC concentration (2~8 wt%) on the mechanical properties and the biocompatibility of the PVA/NaCMC hydrogels. The swelling rate of PVA/NaCMC hydrogels regardless of irradiation rose with increasing NaCMC content from 2 wt% to 8 wt%, while the gelation rate was the reverse. As the NaCMC content increased from 2 wt% to 6 wt%, the compressive strength of the hydrogels increased dramatically from $8.5{\pm}2.0kPa$ to $52.7{\pm}2.5kPa$ before irradiation and from $13.5{\pm}2.9kPa$ to $65.5{\pm}8.7kPa$ after irradiation. When 8 wt% NaCMC was added afterwards, the compressive strength decreased however. The irradiated PVA/NaCMC hydrogels containing 6 wt% NaCMC exhibited the tailored properties of the swelling rate of $118{\pm}3.7%$, the gelation rate of $71.4{\pm}1.3%$, the strength of $65.5{\pm}8.7kPa$, respectively, and no cytotoxicity was observed.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.342-345
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• 2001

A bacterial strain PH-4, which produces an enzyme catalyzing the degradation of crosslinked poly(${\gamma}$-glutamic acid) hydrogels, was isolated and identified as a Flavobacterium sp. The enzyme was obtained by the sonication of the bacterial cells preincubated in a Bouillon medium with shaking, without adding of poly(${\gamma}$-glutamic acid) as an inducer. The products of the hydrogel degraded by the crude enzyme agreed closely with the depolymerized materials in SDS-polyacrylamide gel electrophoresis using methylene blue staining, and with a glutamic acid monomer on thin-layer chromatography, thereby suggesting that strain PH-4 produced a kind of exohydrolase.

• 대한본초학회지
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• 제24권4호
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• pp.95-99
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• 2009

Objectives : This study were carried out to investigate the anti-oxidative activities of $\gamma$-SPE(gamma irradiated shell of Persicae semen extract with ethanol). Methods : Anti-oxidative was measured by DPPH free radical scavenging activities, nitric oxide radical scavenging activities, SOD-like activities, xanthine oxidase radical scavenging activities, nitrite scavenging activities and tyrosinase inhibition activities. Results : Effects of free radial scavenging was increased by irradiation. Tyrosinase inhibition activities was decreased by $\gamma$-SPE. Conclusions : Results suggested that $\gamma$-SPE have a potential as a new anti-oxidative material.

• International Journal of Industrial Entomology and Biomaterials
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• 제31권2호
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• pp.103-106
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• 2015

The oriental tobacco budworm, Helicoverpa assulta (Lepidoptera: Noctuidae), is classified as a quarantine pest that must be controlled for the exportation of Korean paprika to the USA. We performed a confirmatory test of gamma irradiation against the last-instar larvae and pupae of H. assulta in paprika. Previous, small-scale gamma irradiation at a dose of 100 Gy to the last-instar larvae allowed emergence of adults, though they were abnormal, but 200 Gy prevented adult emergence completely. For pupae, irradiation of 5- to 6-day-old pupae with 300 Gy prevented normal emergence completely. To gather confirmatory data applicable to phytosanitary quarantine regulations, larvae and pupae were placed inside paprika in a box and were irradiated with 200 Gy and 300 Gy, respectively. After irradiation with 200 Gy (measured doses 170-199 Gy) of 2,186 individuals of the last-instar larvae, 10.84% survived, but either formed abnormal pupae (7.57%) or died during the pupal stage (3.27%), resulting in no emergence of normal adults. For pupae, the dose of 300 Gy (measured doses 276-319 Gy) given to 1,200 pupae allowed 10.75% to survive and 9.17% to emerge with deformity. However, 1.58% of irradiated pupae emerged normally, requiring an increased dose for complete prevention of normal emergence. Subsequently, an increased dose of 400 Gy (measured doses 340-402 Gy) to 1,005 pupae allowed 88.35% to emerge, but all emerged with deformity. Thus, irradiation treatment with a minimum dose of 400 Gy will provide quarantine security for all premature H. assulta in exported paprika.

• 한국축산식품학회지
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• 제33권3호
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• pp.335-340
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• 2013

This study screened for radio-resistant strains lactic acid bacteria (LAB) by evaluating their capability to survive exposure to ionizing radiation. Ten strains of LAB - Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus delbruekii, Lactococcus lactis, Streptococcus thermophilus, Bifidobacterium breve, and Pediocuccos pentosaceus - were selected and subcultuted twice. The LAB was then further cultured for 3 d at $37^{\circ}C$ to reach 7-10 Log colony-forming units (CFU)/mL prior to irradiation and immediately exposed to gamma rays or electron beams with absorbed doses of 0, 1, 2, 3, 4, 5, 6, 8, and 10 kGy. Gamma irradiation gradually decreased the number of the tested viable LAB, and the effect was irradiation dose dependent. A similar effect was found in electron beam-irradiated LAB. Radiation sensitivity of LAB was calculated as $D_{10}$ values, which ranged from 0.26 kGy to 0.9 kGy and 0.5 kGy to 1.44 kGy with exposure to gamma and electron beam irradiation, respectively, in all tested LAB. L. acidophilus was the most resistant to gamma and electron beam irradiation, with $D_{10}$ values of 0.9 kGy and 1.44 kGy, respectively. These results suggest that L. acidophilus might be suitable for the preparation of probiotics as direct-fed microbes for astronauts in extreme space environments.

• 한국식품저장유통학회지
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• 제6권3호
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• pp.286-291
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• 1999

본 연구는 감마선 조사 시기, 강도 및 조사 후 보존제 처리가 절화장미와 국화의 수명에 미치는 영향을 알기 위하여 시행하였던 바 얻은 결과는 다음과 같았다. 절화장미의 경우 감마선 조사 강도가 0.5 KGy 까지는 절화품질에 미치는 영향이 적다고 할 수 있었으나, 이 보다 강한 조사구에서는 절화장미의 품질이 매우 악화되었으며, 조사 후 설탕용액에 침지한 것은 0.75 KGy 처리구까지 절화의 품질 유지효과가 인정되었다. 조사 후 절화보존제 침지 처리의 효과 실험에서는 2% sucrose, 0.2% silver nitrate, 1.0% Crysal 처리구에서 각각 선도 유지 효과가 어느 정도 인정되었으나, silver nitrate 처리구에서는 절화기부의 갈변부패가 매우 심한 것에서 절화수명의 연장에는 별 효과가 없었음을 알 수 있었다. 절화국화의 경우에는 감마선 조사 강도가 강해질수록 관산가치가 급격히 저하되었으며, 2.0KGy의 강도로 조사한 감마선 처리구에서는 증류수 및 HQS에 침지한 절화를 제외하고 다른 절화 보존제 처리구에서는 절화 수명이 급격히 저하되었다. 절화 보존제의 처리효과 중에 설탕용액의 침지 효과가 제일 우수하였는데, 감마선 무조사구에서 절화가 완전히 시들 때까지도 어느 정도 꽃을 관상 할 수 있을 정도로 절화수명은 유지되었다.

• 한국식품과학회지
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• 제28권3호
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• pp.514-520
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• 1996

감마선 조사기법을 사용하여 새로운 건식공정의 공업용 변성전분 생산 기술개발을 위한 기초연구로서, 시판 옥수수 전분에 직접 감마선을 조사하여 감마선 조사 전분(0-110 kGy)의 이화학적 성질을 검토하였다. 감마선 조사선량이 증가함에 따라 blue value가 직선적으로 감소하였으며, alkali number와 용해도는 크게 증가하였다. $65-95^{\circ}C.$의 온도범위에서 전분용액의 광투과도 또한 감마선 조사선량이 증가함에 따라 현저히 증가하였으며, 물결합능력과 팽윤력은 각각 30 kGy 및 10kGy에서 최대값을 나타내다가 다시 감소하는 경향을 나타내었다. 비조사 전분에 비해 감사선 조사 전분의 호화점도는 현저한 감소 현상을 나타내었다. peak 점도의 경우 7,000 B.U.(비조사 전분)에서 60 B.U.(110kGy)로 그 값이 100배 이상 현저히 감소하였으며 $30^{\circ}C$의 냉각점도도 약 300배 이상 급격한 감소를 나타내었다. 현재 시판중인 산처리 전분은 30kGy의 감마선조사 전분과 유사한 특성을 나타내었으며, 산화전분은 100kGy의 감마선 조사전분과 유사한 성질을 나타내었다.