국내산 키위에서 추출한 protease 조효소액의 안정성과 최적화에 관한 연구

김미현(Mi Hyun Kim),노정해(Jeonghae Rho),송효남(Hyo-Nam Song) 한국식품과학회 2010 한국식품과학회지 Vol.42 No.5

본 연구는 국내산 키위에서 추출한 protease의 특성을 규명하고자 실시하였으며 지금까지 연구되어 오지 않은 근원섬유에 대한 단백분해 활성을 측정하였다. 국내산 키위 crude 효소액은 시료를 buffer에 넣고 균질화한 원심분리액과 포화황산암모늄 처리 후 투석한 두 단계의 시료로 나누었다. 각각은 21.23 mM/mL와 11.58 mM/mL의 활성을 나타내었고 이를 처음 사용하였던 키위의 양으로 환산하면 112.28 mM/g kiwifruit과 45.80 mM/g kiwifruit이었다. 국내산 키위 crude 효소액의 기질에 때한 특이성에서는 카제인과 근원섬유에 대해 높은 활성을 보였으며 그 다음으로 bovine serum albumin, egg white, collagen, elastin 순이었다. 국내산 키위의 단백분해 효소는 pH 2-3에서는 실활하였으며 60℃ 이상의 온도 범위에서는 급격히 실활하였다. 국내산 키위 crude 효소액은 pH 3.0과 pH 7.5 두 곳에서 최적활성을 나타냈고, 최적온도는 카제인을 기질로 한 경우 40℃에서, 근원섬유 50℃에서 최적온도를 나타냈다. 키위 단백질 분해 효소의 카제인에 대한 활성은 염도가 0.5M일 때까지 매우 높다가 급격히 떨어졌으나 근원섬유에 대한 활성은 염의 농도가 높아짐에 따라 서서히 떨어졌다. 키위는 조리중에 연육작용을 위하여 주로 쓰여지고 있으며, 위의 결과로써 우리나라 육류조리와 같이 재워두는 육류조리방법에도 키위가 좋은 연육효과를 나타낼 수 있음을 보였다. In the study, the protease activity of kiwifruit (Actinidia deliciosa Planch) cultivated in Korea was estimated, with specific examination of proteolytic effects on myofibrilar protein. The crude protease extract of kiwifruit was prepared in two ways; one in which the kiwifruit was homogenized with buffer followed by centrifugation, and the other were the supernatant was precipitated by saturated ammonium sulfate followed by dialysis. The former had 21.23 mM/mL of protease activity, which corresponded to 112.28 mM/g kiwifruit utilized, and the latter had 11.58 mM/mL and 45.80 mM/g of kiwifruit. The crude protease extract of the kiwifruit showed high specificity for casein substrate followed by bovine serum albumin, egg white, collagen, and elastin, in order. The enzyme lost proteolytic activity in acidic conditions such as pH 2-3, and at high temperatures over 60℃. It showed optimal activity in both pH 3.0 and pH 7.5 as well as at 40℃ for casein substrate and at 50℃ for myofibrilar protein substrate. The proteolytic activity toward casein was high with up to 0.5M salt, followed by a sharp decrease beyond this concentration. On the other hand the proteolytic activity for myofibrilar protein decreased steadily with increasing of salt concentration. Kiwifruit has been used as a for meat tenderizer for in home cooking and these results support the its tenderizing effectiveness of kiwifruit especially for Korean style marinating of meat for cooking.

된장과 고추장 키위장아찌의 기능성 및 관능 특성

이봉한(Bong Han Lee),남태규(Tae Gyu Nam),조치흥(Chi Heung Cho),조윤섭(Youn-Sup Cho),김대옥(Dae-Ok Kim) 한국식품과학회 2018 한국식품과학회지 Vol.50 No.2

본 연구는 키위 가공 방안의 하나로 소금물 또는 설탕물로 전처리한 후 된장과 고추장을 담금원으로 하여 장아찌를 제조하였다. 기능성 키위장아찌의 활용 가능성을 제시하고자, 키위장아찌의 총페놀, 총플라보노이드, 바이타민 C 함량과 산화방지능을 비교 분석한 후 관능 평가를 실시하였다. 골드키위는 그린키위보다 더 높은 총페놀, 총플라보노이드, 바이타민 C 함량을 보였으며, 장아찌 제조 시 원과보다 높은 총페놀 함량과 산화방지능을 나타냈다. 전처리로 설탕을 이용할 경우 소금과 비교하여 총플라보노이드 함량은 감소하였지만 높은 바이타민 C 함량을 보였다. 또한 담금원으로 된장을 이용 시 고추장과 비교하여 높은 총페놀함량과 산화방지능을 나타냈다. 관능 특성에서는 설탕과 고추장을 이용한 장아찌에서 높은 기호도 평가를 보였으나, 된장으로 만든 장아찌와 비교하여 낮은 산화방지능을 보였다. 된장 처리시 발생하는 맛, 향미 등의 낮은 기호도는 설탕을 이용한 전처리 과정으로 보완하였다. 결론적으로 설탕과 된장을 이용한 키위장아찌 제조는 키위의 낮은 저장성과 기호도에서 발생하는 단점을 극복하며 산화방지능을 높일 수 있는 방법이라고 판단된다. This study aimed to compare total phenolic, total flavonoid, and vitamin C contents, antioxidant capacities, and sensory characteristics of jangachi made from green kiwifruit (Actinidia deliciosa cv. Hayward) and golden kiwifruit (A. chinensis cv. Hort16A), which were cured with doenjang and kochujang. Golden kiwifruit had higher total phenolic, total flavonoid, and vitamin C contents, and antioxidant capacities than green kiwifruit. Jangachi of both cultivars of kiwifruit had generally higher total phenolic and flavonoid contents, and antioxidant capacities than fresh kiwifruit. Doenjang jangachi of kiwifruit had higher total phenolic contents and antioxidant capacities than kochujang jangachi. Jangachi made from golden kiwifruit cured with kochujang, following pretreatment with sugar solution, had the highest overall quality on sensory evaluation among jangachies tested herein. Together, our findings suggest that kiwifruit jangachi may serve as a good dietary source of phenolics and antioxidants.

다양한 파장의 LED 조사를 통한 참다래 과실의 산 함량 조절

백광현(Kwang-Hyun Baek),장명환(Myung Hwan Jang),곽용범(Yong Bum Kwack),이세원(Se Weon Lee),윤해근(Hae Keun Yun) 한국청정기술학회 2010 청정기술 Vol.16 No.2

참다래(‘헤이워드’) 과실을 저온 및 상온 저장 중에, 여러 다른 파장의 light emitting diode (LED) 광원을 조사한 후 과실의 경도, 당도 및 산함량의 변화를 분석하였다. 과실 경도는 4℃보다 25℃에서 크게 감소하였고, 1주 동안 LED 파장을 조사했을 때, 440 nm와 660 nm의 LED 광원을 처리한 참다래가 암실처리 보다 경도가 높게 유지되었고 380 nm UV등과 470 nm 백색 LED를 처리한 과실은 암실의 조건에 비하여 경도가 낮게 조사되었다. 밀봉을 한 참다래는 공기 중에 개방된 참다래보다 모든 처리구에서 경도가 더 높았다. 당도는 25℃에서 공기 중에 개방한 경우, 470 nm 백색 LED 처리구에서는 낮게 나타났으나 암조건과 380nm UV등 처리에서는 15℃Brix 이상을 나타내었다. 참다래 과실의 산함량은 660 nm 적색 LED 처리구에서 52% 감소하였다. 밀봉된 참다래에서 440 nm 청색 LED, 470 nm 백색 LED, 660 nm 적색 LED 광원을 처리하였을 때, 암실에 놓여진 참다래보다 산함량이 각각 52.6, 55.6 및 52.8% 감소하였다. 참다래에 대한 다양한 파장의 LED 조사효과 중에서, 산함량의 감소는 향후 참다래 과실의 수확 후 후숙기간을 조절하는데 활용될 수 있을 것이다. LED 광원은 정확하고 매우 좁은 영역의 파장을 적은 용량의 전력 소모량으로 구현하기 때문에 대표적인 청정 기술로 분류되며, 이러한 LED 광원을 이용한 참다래 과실의 산도 조절은 기존의 에틸렌 등의 화학물 처리보다 안전한 친환경 과실을 생산할 수 있는 청정기술이라 평가된다. The physiological roles of various wavelength of light emitting diode (LED) on ‘Hayward’ kiwifruit experiencing after-ripening were investigated. Various wavelengths from LED light source were irradiated on kiwifruits kept in plastic bags or under open air at 25℃. During two weeks of storage, firmness of Hayward kiwifruits was decreased by 25℃ treatment than by 4℃ treatment. In the 25℃ storage condition, the firmness of kiwifruits was decreased by the treatment of 380 nm UV and 470nm white LED light source. Sweetness of kiwifruits treated with 380 nm UV LED and dark condition at 25℃ increased higher than 15℃Brix. The acidity of kiwifruits under open air was decreased 52% by incubating at 25℃ with 660 nm red LED treatment. The acidity of kiwifruits in plastic bags was decreased 52.6, 55.6, 52.8% by the treatment of 440 nm blue, 470 nm white and 660 nm red LED light source, respectively, compared to that of kiwifruits incubated in darkness at 25℃. Decreased acidity irradiated by 660 nm red LED light source can be applied for regulating periods of the kiwifruit after-ripening process. LED light sources emit very narrow wavelength with a power-saving mode, therefore, the usage of these LED light source for regulating the after-ripening process can be classified as a clean biotechnology producing safe and environment-friendly kiwifruits.

키위 첨가 다당류 혼합겔의 냉동·해동에 따른 품질 특성

윤혜신,오명숙 한국조리과학회 2003 한국식품조리과학회지 Vol.19 No.6

This study was performed to determine the quality characteristics of mixed polysaccharide gels made from K-carrageenan and locust bean gum with various kiwifruit content after freeze-thawing. The syneresis, rupture properties, TPA properties and sensory properties of the mixed polysaccharide gels with various kiwifruit contents after freeze-thawing were measured. The syneresis of the gel with various kiwifruit contents by freeze-thawing was not significantly different, whereas repeating freeze-thawing resulted in remarkable increase in the syneresis of the mixed polysaccharide gels with 5%, 20% and 40% kiwifruit. In terms of the rupture properties, the rupture stress, rupture energy and rupture strain decreased with increasing kiwifruit content after freeze-thawing. In terms of the TPA properties, the adhesiveness, hardness and chewiness increased and the cohesiveness decreased with increasing kiwifruit content after freeze-thawing. The rupture properties, springiness and cohesiveness of the gel by freeze-thawing were lower than those of the gel stored in the refrigerator. In contrast, the gumminess, hardness and chewiness of the gel after freeze-thawing were higher than those of the gel stored in the refrigerator. The results showed that the gel became crumbly and tough as a result of freeze-thawing. In the sensory evaluation, the overall acceptability of the gel after freeze-thawing was highest at the 30% kiwifruit content, and differences in the sensory properties between the gel after freeze-thawing and that stored in the refrigerator were small. Therefore, mixed polysaccharide gels with kiwifruit after freeze-thawing could be useful despite the small decrease in quality.

Alternaria alternata에 의한 참다래 갈색둥근무늬병

정인호,김경희,허재선,고영진,임명택,신종섭 한국식물병리학회 2008 식물병연구 Vol.14 No.1

Brown leaf spots on leaves of kiwifruit(Actinidia deliciosa) were observed at farmers' orchards in Suncheon and Goheung, Jeonnam Province, Korea in June, 2006. They developed to form dark brown ring spots and severely infected leaves resulted in defoliation during the growing season of kiwifruit. Alternaria sp. was isolated from the diseased leaves repeatedly and was identified as Alternaria alternata on the basis of its mycological characteristics on potato dextrose agar and its pathogenicity was confirmed by wound inoculation on healthy leaves of kiwifruit. A. alternata formed gray to dark sooty gray colony and produced numerous conidia on potato dextrose agar. The conidia, commonly in long chains of 5 or more produced on conidiophores, have 3~5 transverse and 1~2 longitudinal septa and mostly ovoid or obclavate in shape and were pale brown golden brown in color. The condia were 16.5~42.1×6.7~19.5 μm in size and conidiophores were 8.6~112.7 μm in length. This is the first report on the brown ring spot on leaves of kiwifruit caused by A. alternata in Korea. Brown leaf spots on leaves of kiwifruit(Actinidia deliciosa) were observed at farmers' orchards in Suncheon and Goheung, Jeonnam Province, Korea in June, 2006. They developed to form dark brown ring spots and severely infected leaves resulted in defoliation during the growing season of kiwifruit. Alternaria sp. was isolated from the diseased leaves repeatedly and was identified as Alternaria alternata on the basis of its mycological characteristics on potato dextrose agar and its pathogenicity was confirmed by wound inoculation on healthy leaves of kiwifruit. A. alternata formed gray to dark sooty gray colony and produced numerous conidia on potato dextrose agar. The conidia, commonly in long chains of 5 or more produced on conidiophores, have 3~5 transverse and 1~2 longitudinal septa and mostly ovoid or obclavate in shape and were pale brown golden brown in color. The condia were 16.5~42.1×6.7~19.5 μm in size and conidiophores were 8.6~112.7 μm in length. This is the first report on the brown ring spot on leaves of kiwifruit caused by A. alternata in Korea.

Characterization of Antibacterial Strains against Kiwifruit Bacterial Canker Pathogen

Min-Jung Kim,Dae-Han Chae,Gyeongjun Cho,Da-Ran Kim,Youn-Sig Kwak 한국식물병리학회 2019 Plant Pathology Journal Vol.35 No.5

Kiwifruit (Actinidia spp.) is an economically important crop and a bacterial canker disease, caused by Pseudomonas syringae pv. actinidiae (Psa), is the most destructive disease in kiwifruit production. Therefore, prevent and control of the disease is a critical issue in kiwifruit industry worldwide. Unfortunately, there is no reliable control methods have been developed. Recently, interest in disease control using microbial agents is growing. However, kiwifruit microbiota and their roles in the disease control is mainly remaining unknown. In this study, we secured bacterial libraries from kiwifruit ecospheres (rhizosphere, endospere, and phyllosphere) and screened reliable biocontrol strains against Psa. As the results, Streptomyces racemochromogenes W1SF4, Streptomyces sp. W3SF9 and S. parvulus KPB2 were selected as anti-Psa agents from the libraries. The strains showed forcible antibacterial activity as well as exceptional colonization ability on rhizosphere or phyllosphere of kiwifruit. Genome analyses of the strains suggested that the strains may produce several anti-Psa secondary metabolites. Our results will contribute to develop biocontrol strains against the kiwifruit canker pathogen and the disease management strategies.

Characterization of Antibacterial Strains against Kiwifruit Bacterial Canker Pathogen

Kim, Min-Jung,Chae, Dae-Han,Cho, Gyeongjun,Kim, Da-Ran,Kwak, Youn-Sig The Korean Society of Plant Pathology 2019 Plant Pathology Journal Vol.35 No.5

Kiwifruit (Actinidia spp.) is an economically important crop and a bacterial canker disease, caused by Pseudomonas syringae pv. actinidiae (Psa), is the most destructive disease in kiwifruit production. Therefore, prevent and control of the disease is a critical issue in kiwifruit industry worldwide. Unfortunately, there is no reliable control methods have been developed. Recently, interest in disease control using microbial agents is growing. However, kiwifruit microbiota and their roles in the disease control is mainly remaining unknown. In this study, we secured bacterial libraries from kiwifruit ecospheres (rhizosphere, endospere, and phyllosphere) and screened reliable biocontrol strains against Psa. As the results, Streptomyces racemochromogenes W1SF4, Streptomyces sp. W3SF9 and S. parvulus KPB2 were selected as anti-Psa agents from the libraries. The strains showed forcible antibacterial activity as well as exceptional colonization ability on rhizosphere or phyllosphere of kiwifruit. Genome analyses of the strains suggested that the strains may produce several anti-Psa secondary metabolites. Our results will contribute to develop biocontrol strains against the kiwifruit canker pathogen and the disease management strategies.

조기낙엽에 따른 참다래(골드러쉬) 무착과 유목 액아의 발아와 착화

곽용범 ( Yong Bum Kwack ),김홍림 ( Hong Lim Kim ),채원병 ( Won Byoung Chae ),이재한 ( Jae Han Lee ),이응호 ( Eung Ho Lee ),진국 ( Jin Gook Kim ),이용복 ( Yong Bok Lee ) 한국환경농학회 2013 한국환경농학회지 Vol.32 No.3

BACKGROUND: Kiwifruit, which was introduced to Korea in late 1970s, is a warm-temperate fruit tree, whose leaves are easily damaged by wind because of their large size. To produce high quality fruits, efficient windbreak is necessary to protect leaves until harvest. In Korea, typhoons from July onwards usually influence the production of kiwifruit. Damages from typhoons include low fruit quality in the current year and low flowering ratio the following year. This study was conducted to investigate the effect of early defoliation of kiwifruit vines from July to October on the regrowth of shoot axillary buds the current year and bud break and flowering the following year. METHODS AND RESULTS: Scions of kiwifruit cultivar ‘Goldrush’ were veneer grafted onto five?year?old Actinidia deliciosa rootstocks, planted in Wagner pots (13L) and grown in a rain shelter. Kiwifruit leaves in the proximity of leaf stalk were cut by lopping shears to simulate mechanical damage from typhoon since only leaf stalks were left when kiwifruit vines were damaged by typhoons. Kiwifruit vines were defoliated from July 15 to October 14 with one monthintervals and degrees of defoliation were 0, 25, 50, 75 and 100%. All experiments were conducted in the rain shelter and replicated at least five times. Defoliation in July 15 resulted in a high regrowth ratio of 20?40% regardless of degree of defoliation but that in August 16 showed only 5.8% of regrowth ratio in the no defoliation treatment; however, more than 25% of defoliation in August 16 showed 17?23% of regrowth ratio. In September 15, regrowth ratio decreased further to less than 10% in all treatments and no regrowth was observed in October 14. Percent bud break of all defoliation treatments were not significant in comparison to 64.7% in no defoliation except for 42.1% and 42.9% in 100% defoliation in July 15 and August 16, respectively. Floral shoot in the no defoliation treatment was 70.2% and defoliation of 50% or less resulted in the same or increased floral shoot ratio in July 15, August 16, and September 15; however, defoliation in October 14 showed no difference in all treatments. In flower number per floral shoot, 2?3 flowers appeared in no defoliation and only 1 flower was observed when the vines were defoliated more than 50% in July 15 and September 15. In October 14, contrary to the floral shoot ratio, flower number decreased with increased defoliation. CONCLUSION(S): Therefore, it is suggested that dormancy of ‘Goldrush’ axillary buds, was started in August and completed in October. The effect of defoliation on bud break of axillary buds the following year was insignificant, except for 100% defoliation in July 15 and August 16. From July 15 to September 15, floral bud ratio was significantly reduced when more than 50% of leaves were defoliated compared to no defoliation. Also, the number of flowers per flower?bearing shoot the following year decreased by less than 50% when compared to no defoliation, and this decrease was more prominent in September 15 than July 15 and August 16.

Effects of freeze-drying on antioxidant and anticholinesterase activities in various cultivars of kiwifruit (Actinidia spp.)

황정승,조치흥,백무열,박승국,허호진,조윤섭,김대옥 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.1

Oxidative stress contributes to neurodegenerative disorders such as Alzheimer’s disease. Phenolic antioxidants can efficiently reduce oxidative stress. In this study, we evaluated the effects of the freeze-drying process on phenolics, antioxidants, and cholinesterase inhibition in five cultivars of kiwifruits grown in Korea, Actinidia chinensis cv. Hort16A, cv. Happygold, and cv. Haegeum; A. deliciosa cv. Hayward; and A. eriantha cv. Bidan, by comparing them with their fresh counterparts. Among the five cultivars of both fresh and freeze-dried kiwifruits tested in this study, cv. Bidan had the highest levels of total phenolics, total flavonoids, and antioxidants, and cv. Hayward had the lowest. Freezedried kiwifruits inhibited acetylcholinesterase and butyrylcholinesterase that catalyze the breakdown of acetylcholine (neurotransmitter). On sensory evaluation, cv. Happygold had the highest overall preference scores among the freeze-dried kiwifruits. The results suggest that freeze-dried kiwifruit could serve as a good source of antioxidants and cholinesterase inhibitors.

후숙시기 동안 참다래의 품질, 기능성 및 액티니딘 함량 변화 조사

남승희 한국식품저장유통학회 2016 한국식품저장유통학회지 Vol.23 No.3

Kiwifruit (Actinidia chinensis, Hayward) was stored at 25℃ for 0~30 days and investigated to find out the optimum storage time to obtain the best physical and functional properties for consumers’ preference. Kiwifruits was stored at different time period (0, 5, 10, 15, 20, and 30 days) for investigating their physiochemical quality, nutritional components, and functional characteristics. Kiwifruits stored for 20~30 days showed the best physiochemical quality such as higher total acidity and proper firmness. They were also more enriched with dietary fibers, free sugar, and organic acid, although no significant changes were observed in crude protein, crude fat, and moisture content. For functional properties, kiwifruits stored for 20 days showed significantly higher contents of total phenolics, flavonoids, and actinidin. In addition, it showed stronger antioxidant activity, whitening effect, and proteolytic activity when compared with other samples. SDS-PAGE analysis showed the presence of actinidin enzyme in kiwifruits. These results indicated that the kiwifruits stored for 15~20 days possessed excellent quality and high concentrations of nutritional and functional compounds, which could be best for both fresh consumption and product processing