• 한국식품영양학회지
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• 제34권4호
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• pp.390-397
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• 2021

The purpose of this study was to investigate at how the quality of citron changed during storage as a result of the browning inhibitor treatment. In the browning inhibitor treatment, Vit.C, Vit.C+NaCl, Vit.C+NaCl+CD substances were used. As a result of investigating the browning degree, Vit.C+NaCl+CD showed the lowest value of 0.76 when stored for 12 weeks. The 𝚫E of the chromaticity value indicated that significant color change occurred when the value was high. As the Vit.C+NaCl+CD mixture showed the lowest value of 46.01 at 25℃, it was found that browning did not occur much compared to other treatments. The change in polyphenol oxidase (PPO) activity of citron increased as browning progressed. Among the browning inhibitor solutions, Vit.C+NaCl+CD solution showed the lowest value 118.8 u/g at 25℃ after 12 weeks. Based on these findings, it seems that CD mixing solution can be used as a citron browning inhibitor.

• The Plant Pathology Journal
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• 제39권2호
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• pp.159-170
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• 2023

Spot blotch disease of wheat caused by Bipolaris sorokiniana (Sacc.) Shoem is considered as an economically important disease which affects all the growing stages of wheat crop. Therefore, it is important to search some effective management strategies against the spot blotch pathogen. Some synthetic elicitor compounds (salicylic acid, isonicotinic acid, and chitosan) and nano-particles (silver and aluminum) were tested against the pathogen to observe the change in biochemical activity and defense action of wheat plant against spot blotch disease. All the tested elicitor compounds and nano-particles showed a significant increase in activity of peroxidase, polyphenol oxidase (PPO), and total phenol over control. The highest increase in activity of peroxidase was recorded at 72 h from chitosan at 2 mM and 96 h from silver nano-particle at 100 ppm. Maximum PPO and total phenol activity were recorded from chitosan at 2 mM and silver nano-particle at 100 ppm as compared to pathogen-treated and healthy control. The lowest percent disease index, lowest no. of spots/leaf, and no. of infected leaves/plant were found in silver nano-particle at 100 ppm and chitosan at 2 mM, respectively. The use of defense inducer compounds results in significantly up-regulated enzymatic activity and reduced spot blotch disease. Therefore, chitosan and silver nano-particle could be used as alternative methods for the management of spot blotch disease.

• 한국작물학회지
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• 제55권3호
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• pp.220-225
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• 2010

본 연구는 콩나물용 플라스틱 필름봉지(OPP+PE)에 포장되어 유통되는 콩나물을 냉장고 온도인 $3^{\circ}C$와 대형 마트의 진열대 온도인 $13^{\circ}C$로 저장한 콩나물의 품질변화에 미치는 요인을 분석하여, 유통 기간 중 콩나물의 품질변화에 대한 기초 자료를 알아보고자 하였으며, 그 결과는 다음과 같다. 1. 플라스틱 필름 봉지에 포장된 콩나물은 냉장 온도인 $3^{\circ}C$에 비해 마트 진열대 온도인 $13^{\circ}C$에서 세근의 발생수가 많았으며, 하배축과 뿌리의 길이도 더 길어졌으며, 수분함량과 생체중에서도 $13^{\circ}C$에서 더 늘어났다. 경도 조사에서는 $13^{\circ}C$에서 경도 값의 증가로 하배축이 질겨졌으며, 색도 조사에서도 $3^{\circ}C$의 자엽과 하배축에서는 거의 변화를 보이지 않았으나, $13^{\circ}C$에서는 하배축은 갈색으로 변하고, 자엽은 푸르게 변하였다. 2. 자엽과 하배축의 환원당 함량변화에서는 저장 기간이 경과함에 따라 감소하였는데, 저장 기간 3일차부터 $13^{\circ}C$ 저장조건에서 하배축에서 변화 폭이 크게 나타났다. 3. 유리당의 성분 중에서는 galactose와 fructose의 함량이 높았고, 유리당 함량의 변화는 $3^{\circ}C$에 비해서 $13^{\circ}C$에서 더욱 민감하게 나타났으며, galactose와 fructose의 함량은 2~3배정도 증가하였다. 4. 유리 아미노산의 함량 변화도 $13^{\circ}C$에서 크게 증가하였으며, 저장 3일차부터 변화의 폭이 크게 조사되었다. 5. 조단백질의 함량 변화에서는 30.9~35.4%로 증가하였으며, $13^{\circ}C$에서 변화의 폭이 크게 나타났다. 6. PPO 활성에서는 $3^{\circ}C$에서는 4일차부터 크게 증가하여 저장 9일차에서 계속 증가되었으나, $13^{\circ}C$에서는 저장 1일차부터 PPO 활성이 크게 증가하여 저장 7일 차부터는 더 이상의 증가가 없었다.

• 한국식품영양학회지
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• 제31권5호
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• pp.689-695
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• 2018

This study was carried out to select apple cultivars suited for the fresh cutting or minimal processing as investigating correlation between total phenol and ascorbic acid as browning factors and the enzymatic browning degree. In soluble solid-acid ratio, 'Gamhong' and 'Arisoo' were highest value of 71.69 and 71.52 compared with other cultivars. And the change of lightness (${\Delta}L$) and color (${\Delta}E$) in 'Gamhong' and 'Arisoo' showed lower than other cultivars while 'Arkansas black' was highest change of lightness and color as ${\Delta}L$ 8.27, ${\Delta}E$ 13.86 respectively. Total phenol and ascorbic acid contents in 'Arkansas black' were highest such as 334.3 mg GAE/100 g and 9.22 mg/100 g, respectively. And polyphenol oxidase (PPO) activity also was the highest such as 14.43unit in 'Arkansas black'. The correlation test showed browning of apple was significantly dependent on ${\Delta}L$, ${\Delta}E$, total phenol, ascorbic acid contents and PPO activity (p<0.01). On the contrary, no significant correlation had been determined between the browning and ascorbic acid oxidase (AAO) activity. Thus, it seemed that the browning of apple was not only due to oxidation of ascorbic acid but also total phenol. It was suggested that 'Gamhong' and 'Arisoo' were suitable for fresh cutting or minimal processing.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.95.1-95
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• 2003

Plant growth promoting rhizobacteria (PGPR) have been shown to suppress phytopthora blight. This suppression has been related to both microbial antagonism and induced resistance. The PGPR isolates were screened by dual culture plate method and most of the isolates were showed varying levels of antagonism. Among the PGPR isolates pyoverdin, pyochelin and salicylic acid producing strains showed the maximum inhibition of mycelial growth of Phytopkhora capsici and increased plant growth promotion in red pepper. PGPR isolates further analysed for its ability to induce production of defence related enzymes and chemicals. The activities such as Phenyle alanin ammonia Iyase (PAL), Peroxidase (PO), Polyphenol oxidase (PPO) and accumulation of phenolics were observed in PGPR pretreated red pepper plants challenged with Phytopkhora capsici. The present study shows that an addition of direct antagonism and plant growth promotion, induction of defense related enzymes involved to enhance resistance against invasion of P. capsici in red pepper.

• 한국식품과학회지
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• 제27권6호
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• pp.991-996
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• 1995

비열처리공법 중 하나로 새롭게 주목받고 있는 초고압처리를 신선초 녹즙에 적용하여 미생물의 살균정도 및 갈변효소의 불활성화정도를 살펴보았다. 실험에는 $3800\;kg_f/cm^2{\sim}6700\;kg_f/cm^2$ 범위의 압력에서 $3{\sim}17\;min$동안 처리하였으며 반응표면분석법(RSM)을 이용하여 미생물 및 효소 불활성화의 최적조건을 구하고자 하였다. 반응표면분석결과 $5700\;kg_f/cm^2$ (558.6 MPa)에서 7.16 min 처리할 때 3.44 log cycles의 총균수 감소효과를 얻을 수 있을 것으로 예상되었다. 대장균의 경우, 모든 처리 조건에서 완전살균이 가능하였다. Peroxidase나 PPO와 같은 갈색화효소는 초고압처리에 의해서 쉽게 불활성화 되지 않았으며, 미생물이나 효소의 불활성화는 처리시간보다는 압력에 더욱 의존함을 알 수 있었다.

• 한국식품저장유통학회지
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• 제21권6호
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• pp.776-783
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• 2014

절단 배추를 예열처리하고 LDPE 필름 포장하여 단기저장하면서 이화학적인 품질특성과 갈변도를 조사하였다. $40^{\circ}C$에서 1, 2, 4, 8시간동안 예열처리한 후 SDS-PAGE 법으로 단백질 밴드를 조사한 결과, 예열처리구에서 대조구에 비하여 HSP 밴드로 추정되는 60, 39, 33, 12 kDa 밴드가 강하게 나타났으며, 이 중 4시간 예열처리구(HS 4)가 가장 발현율이 높았으며 중량감소율도 적었다. 8주 동안 저장 중 예열처리한 절단배추의 중량감소율 및 적정산도는 거의 변화가 없었으며, 가용성 고형분 함량은 4시간 예열처리구가 가장 적게 감소하였다. 갈변도는 HS 4가 가장 적었다(Con>HS 1>HS 8>HS 2>HS 4, p<0.05). PPO활성은 저장 중 모든 구에서 지속적으로 증가하였으며, HS 4가 가장 낮았고 총페놀성 화합물은 모든 처리구에서 유사하게 감소하였다. 예열처리한 절단배추에서 HSP 밴드의 발현을 확인하였으며, 4시간 예열처리구의 단기 저장 효과가 가장 좋았다.

• 원예과학기술지
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• 제32권3호
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• pp.353-358
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• 2014

치콘의 판매 중 상품성 저하의 원인이 되는 치콘 절단면적변 현상을 억제하기 위해 열수 침지 실험을 실시하였다. 열수침지처리로는 대조구($20^{\circ}C$ 1분)과 $38^{\circ}C$에서의 4분, 8분, $42^{\circ}C$에서의 2분, 4분, 그리고 $45^{\circ}C$에서의 1분, 2분을 두었다. 색차계로 측정한 ${\Delta}a^*$과 ${\Delta}h$값은 $42^{\circ}C$ 2분 처리에서는 가장 낮게 유지되었으며, $42^{\circ}C$의 2분과 $45^{\circ}C$의 1분 처리구에서는 대조구보다 유의 있는 낮은 값을 나타내었다. $10^{\circ}C$에 저장 6일째 관능 평가한 절단면의 적변지수는 $42^{\circ}C$의 2분과 4분 처리 그리고 $45^{\circ}C$의 1분 처리에서 낮았다. 적변의 원인 물질이 되는 총페놀함량을 저장 6일째 조사하였는데, 이 또한 절단면의 색변화가 적었던 $42^{\circ}C$의 2분과 4분 처리 그리고 $45^{\circ}C$의 1분 처리에서 낮았다. 페놀물질 합성에 관여하는 PAL 활성은 $42^{\circ}C$ 2분 처리에서는 가장 낮은 값을 보였으며, $42^{\circ}C$의 2분와 $45^{\circ}C$의 1분 처리구에서는 대조구보다 유의 있는 낮은 수치를 보였다. 그러나 가장 강한 열처리였던 $45^{\circ}C$의 2분 처리에서는 절단면의 적변이 대조구와 유사한 수준으로 진행되었으며, 페놀함량과 PAL 활성도 대조구와 차이가 없었다. 공기에 노출된 절단조직에서 페놀물질을 산화시켜 적변을 일으키는 PPO의 활성은 $42^{\circ}C$와 $45^{\circ}C$의 모든 처리구에서 낮았는데, 특히 다른 조사항목에서는 모두 대조구와 유사한 수준을 보였던 $45^{\circ}C$의 2분 처리구가 가장 낮은 수치를 보였다. 또한 각 조사항목간 상관관계에서, PPO를 제외한 모든 조사항목간에서는 대부분 고도의 상관관계를 보였으며, 특히 관능평가한 적변지수와 ${\Delta}h$값은 $r=0.927^{***}$를, PAL 활성과 총 페놀물질 함량과는 $r=0.942^{***}$의 고도의 상관관계를 보였다.

• 한국식품조리과학회지
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• 제28권3호
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• pp.319-326
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• 2012

This study was designed to investigate the properties related to browning of hot water and 80% ethanol extracts of green tea (Camellia sinensis) and propolis. The extracts were assessed for polyphenol oxidase (PPO) inhibitory activity and total phenolic and flavonoid contents. In addition, apples were cut into 15 mm thick slices and dipped for 1 min in 0.5% of the green tea extracts and the propolis solutions and stored at room temperature for 24 h. The PPO inhibitory activity of the green tea extracts was better than that of the propolis. The highest DPPH free radical scavenging activity (90.81%), total phenol contents (170.42 mg/mL) and the metal chelating effects (45.93%) were measured in the green tea hot water extracts. The mineral content of the green tea water extracts was 69,328.44 ppm potassium and 2,409.42 ppm magnesium. After 24 h, the ${\Delta}E$ value of the apple slices treated with the green tea water extracts was the lowest (1.35). The antibrowning effects of the green tea extracts were higher than those of propolis in the apple slices.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.407-415
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• 2012

An endophytic bacterium, Bacillus thuringiensis GS1, was isolated from bracken (Pteridium aquilinum) and found to have maximal production of chitinase (4.3 units/ml) at 5 days after culture. This study investigated the ability of B. thuringiensis GS1 to induce resistance to Rhizoctonia solani KACC 40111 (RS) in cucumber plants. Chitinase activity was greatest in RS-treated plants at 4 days. ${\beta}$-1,3-Glucanase activity was highest in GS1-treated plants at 5 days. Guaiacol peroxidase (GPOD) activity increased continuously in all treated plants for 5 days. Ascorbate peroxidase (APX) activity in RS-treated plants was increased 1.5-fold compared with the control at 4 days. Polyphenol oxidase (PPO) activity in RS-treated plants was increased 1.5-fold compared with the control at 3 days. At 5 days after treatment, activity staining revealed three bands with chitinase activity (Ch1, Ch2, and Ch3) on SDS-PAGE of cucumber plants treated with GS1+RS, whereas only one band was observed for RS-treated plants (Ch2). One GPOD isozyme (Gp1) was also observed in response to treatment with RS and GS1+RS at 4 days. One APX band (Ap2) was present on the native-PAGE gel of the control, and GS1- and GS1+RS-treated plants at 1 day. PPO bands (Po1 and Po2) from RS- and GS1+RS-treated plants were stronger than in the control and GS1-treated plants upon native-PAGE at 5 days. Taken together, these results indicate that the induction of PR proteins and defense-related enzymes by B. thuringiensis GS1 might have suppressed the damping-off caused by R. solani KACC 40111 in cucumber plants.