• Journal of Applied Biological Chemistry
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• 제49권3호
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• pp.75-81
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• 2006

A full-length cDNA encoding dihydroflavonol 4-reductase (st-dfr) of potato was isolated by rapid amplification of cDNA ends, and their expression was investigated from purple-fleshed potato (Solanum tuberosum L. cv. Jashim). The st-dfr exists as a member of a small gene family and its transcripts was abundant in the order of tuber flesh, stem, leaf, and root. The expressions of st-dfr gene were light inducible and cultivar dependant. Transgenic potato plants harboring antisense st-dfr (AS-DFR) sequences were analyzed. The accumulation of mRNA was nearly completely inhibited as a result of introducing an AS-DFR gene under the control of the 35S CaMV promoter into the red tuber skin Solanum tuberosum L. cv. Desiree. The anthocyanin content of the tuber peels of the transgenic lines was dramatically decreased by up to 70%. The possible production of flavonols in the peels of AS-DFR transgenic potatoes was discussed.

• 한국육종학회지
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• 제41권4호
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• pp.385-390
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• 2009

A resveratrol synthase (RS) gene was isolated from peanut (Arachis hypogaea, L. cv. Jinpoong) plants. This gene was placed under the control of the cauliflower mosaic virus 35S promoter (CaMV35S) and introduced into two Korean varieties of potato (Solanum tuberosum L. cvs. Jasim and Jowon) plants by Agrobacterium-mediated gene transfer. Putative transformants were screened by PCR with primers designed from CaMV 35S promoter, NOS terminator and RS gene. Most of selected transgenic potato plants showed the amplification of expected fragments by PCR of genomic DNA with gene-specific primers, while they were absent in untransformed control plants. Expression of the resveratrol synthase gene was also examined by northern blot analysis. The transformants showed a band which was lacking in the control plant, confirming that the introduced gene is transcribed into mRNA in the transformants. The strength of the band, which reflected the level of mRNA expression, differed among the individual transformants. Among the transformants obtained, the highest trans-resveratrol content in the transgenic young leaves of purple-fleshed "Jashim" was $2.11{\mu}gg^{-1}$ fresh weight and that in the microtubers in vitro of purple fleshed "Jashim" was $8.31{\mu}gg^{-1}$ fresh weight. This amount of resveratrol may have a positive biological effect on human health.

• Food Science and Biotechnology
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• 제14권1호
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• pp.117-122
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• 2005

Polyphenoloxidase (PPO) was extracted from Solanum tuberosum Jasim by various chromatographic methods and was subsequently purified and characterized. PPO was purified upto 78-fold from the crude extract. SDS-PAGE profile of the enzyme showed a major subunit of PPO with molecular weight of 40 kDa. The optimum pH and temperature for the maximum activity of PPO was 6.5 and $25^{\circ}C$, respectively. The enzyme was found to be quite stable between 10 and $40^{\circ}C$, whereas it was almost inactivated at $70^{\circ}C$ when incubated for 30 min. Substrate specificity study indicated that catechol was the most suitable substrate for PPO isolated from purple-fleshed potato with a $K_m$ value of 21.1 mM. The most effective inhibitor was ascorbic acid, followed by L-cysteine, citric acid, EDTA, and boric acid. Studies on the effect of metal ion on PPO activity showed that magnesium and copper were inhibitory, while iron and zinc ions increased the activity of PPO.

• 생물환경조절학회지
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• 제15권2호
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• pp.204-210
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• 2006

고령지농업연구소에서 육성된 '자심' 감자(Solanum tuberosum L.) 괴경의 자주색 육색은 안토시아닌 색소의 축적에 기인한다. 본 연구는 이러한 '자심' 감자의 괴경 조직에 안토시아닌이 축적될 때 결정적으로 관여하는 기상 환경요인을 분석하고 색소 함량 증대를 위한 질소시비 기준을 설정하기 위하여 수행되었다. 기상 환경요인이 뚜렷하게 다른 3개 지역에서 파종시기 또는 재배 작형을 달리하여 '자심' 감자를 재배하고 수확된 괴경의 안토시아닌 함량을 분석한 결과, 수확일을 기준으로 수확전 30일 동안의 야간온도가 낮을수록 괴경내 안토시아닌 축적이 왕성한 것으로 나타났다. 안토시아닌 축적에 영향을 미치는 질소시비 수준의 효과를 분석한 결과 고랭지인 대관령에서는 권장시비량 처리구에 비해 감량시비 혹은 증량시비 처리구에서 안토시아닌 함량이 낮은 결과를 보였다. 그러나 평난지인 강릉에서는 시비수준간 뚜렷한 차이를 보이지 않았다. 이러한 결과로 볼 때 안토시아닌이 고농도로 축적된 자주색 육색의 '자심' 감자를 생산하기 위해서는 적절한 재배지대 및 작형의 선택과 시비관리가 매우 중요할 것으로 생각된다.

• 동의생리병리학회지
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• 제21권3호
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• pp.605-610
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• 2007

This experimental study was performed to evaluate the effects of ehtanol extract of Purple Solanum tuberosum L(EPSTL) on obesity and hyperlipidemia in rats induced by high fat diet. Sprague-Dawley rats were divided into normal group, control group, EPSTL (100 mg/kg and 200 mg/kg) treated group. EPSTL was orally administered to the obese rats by high fat diet for 6 weeks. The effect of EPSTL on obesity and hyperlipidemia were examined in vitro and in vivo as follows : EPSTL effectively inhibited the differentiation of 3T3-L1 adipocytes in a concentration dependent manner. EPSTL significantly lowered body weight of rats fe high fat diet for 6 weeks from 4 weeks treatment compared with untreated control. EPSTL significantly reduced the weight of retroperitoneal fat only at 100 mg/kg and epididymal fat pad in rats fed high fat diet for 4 weeks at 100 and 200 mg/kg. EPSTL significantly reduced the level of triglyceride at 200 mg/kg, while EPSTL tended to lower the levels of total lipid and phospholipid in rats fed high fat diet for 4 weeks with no significance. EPSTL significantly attenuated the level of total cholesterol, LDL and atherosclerosis index (Al) as well as increased the level of HDL at 200 mg/kg. EPSTL significantly reduced the levels of total lipid and triglyceride of hepatic tissues in rats fed high fat diet for 4 weeks at 200 mg/kg. EPSTL significantly lowered the level of insulin, while it did not affect leptin compared with untreated control. Taken together, these results suggest that EPSTL can be used for the treatment or prevention of hyperlipidemia and obesity.

• Natural Product Sciences
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• 제15권3호
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• pp.134-138
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• 2009

In an attempt to establish anti-ulcerogenic activity of potato tubers, inhibitory activity against ethanol- and indomethacin-induced gastric ulcer models in rats was evaluated for the first time. From several varieties of potato tubers including Solanum tuberosum L. cv. Superior (white skin and fresh potato) and two new varieties of (Bora valley and Gogu valley), raw potato juice was prepared and the starch was obtained from each juice by filtration and drying. Upon oral administration to rats, raw potato juice showed more or less inhibitory activity. The starch showed higher and dose-dependent inhibitory activity, suggesting that the active ingredient in raw potato juice may be the starch. Particularly, the starch obtained from the tubers of new potato variety, "Bora valley," with purple color, showed the highest inhibitory activity (62.4% and 37.1% inhibition of ulcer index at 500 mg/kg), while omeprazole (proton pump inhibitor) used as a reference drug showed 74.4% and 75.7% inhibition at 20 mg/kg against ethanol- and indomethacin-induced ulcer formation, respectively. The present study provides a first evidence of anti-ulcerogenicity of raw potato juice and the starch. Especially, the starch from "Bora valley" strongly inhibited ulcer formation in rats. Considering that these are food components, they may be safely used for anti-ulcerogenic nutraceuticals.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2018년도 추계학술대회
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• pp.42-42
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• 2018

Anthocyanins has a strong antioxidant capacity but exhibit poor stability in water. Therefore, stability of anthocyanin from purple potato (Solanum tuberosum L.) was encapsulated by the application of food polymers. Solid formulation of purple potato was prepared using whey protein, tapioca and lecithin by capillary rheometer at $80^{\circ}C$. The ratio of the polymer and potato powder was 2:8. Total phenolic compound, total flavonoid, total anthocyanin and antioxidant activity was investigated by the spectrophotometer. Result revealed that total phenolic compound (TP) ($5321{\mu}g/100g$), total flavonoid (TF) ($1352{\mu}g/100g$) total anthocyanin (TA) ($764{\mu}g/100g$) and free radical antioxidant activity (DPPH) (86%) was higher in 0.01 M acetic acid mediated lecithin based formulation compared to control (Potato powder) (TP: $1357{\mu}g/100g$; TF) ($634{\mu}g/100g$, TA) ($264{\mu}g/100g\;DPPH$) (64%). Lecithin is a strong emulsifier having capacity to extract bioactive compound and encapsulate extracted compound by nonpolar tail and negatively charged head. Therefore, it would be concluded that lecithin might be used as an encapsulating agent for the bioactive compound from purple potato.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2018년도 추계학술대회
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• pp.274-274
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• 2018

Anthocyanins has a strong antioxidant capacity but exhibit poor stability in water. Therefore, stability of anthocyanin from purple potato (Solanum tuberosum L.) was encapsulated by the application of food polymers. Solid formulation of purple potato was prepared using whey protein, tapioca and lecithin by capillary rheometer at $80^{\circ}C$. The ratio of the polymer and potato powder was 2:8. Total phenolic compound, total flavonoid, total anthocyanin and antioxidant activity was investigated by the spectrophotometer. Result revealed that total phenolic compound (TP) ($5321{\mu}g/100g$), total flavonoid (TF) ($1352{\mu}g/100g$) total anthocyanin (TA) ($764{\mu}g/100g$) and free radical antioxidant activity (DPPH) (86%) was higher in 0.01 M acetic acid mediated lecithin based formulation compared to control (Potato powder) (TP: $1357{\mu}g/100g$; TF) ($634{\mu}g/100g$, TA) ($264{\mu}g/100g\;DPPH$) (64%). Lecithin is a strong emulsifier having capacity to extract bioactive compound and encapsulate extracted compound by nonpolar tail and negatively charged head. Therefore, it would be concluded that lecithin might be used as an encapsulating agent for the bioactive compound from purple potato.

• 산업식품공학
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• 제21권2호
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• pp.167-173
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• 2017

본 연구에서는 고유의 자색 안토시아닌을 함유하고 있는 PFPP를 이용하여 매쉬드 포테이토를 제조하고 이의 물리화학적 특성을 확인하였다. PFPP와 전지분유, 덱스트린을 혼합하여 ready-to-eat (RTE) 매쉬드 포테이토 제품을 제조하기 위하여 세 구성 성분의 최적 혼합비를 도출하고자 혼합물 실험방법을 이용하였다. 다양한 배합비에서 매쉬드 포테이토의 색도, 안토시아닌 함량, 유변학적 특성의 차이를 관찰하였으며 PFPP와 전지분유의 배합비에 따라 매쉬드 포테이토의 구조가 변화하여 다른 유변학적 gel 특성을 나타내었다. PFPP의 함량은 주로 적색도와 안토시아닌 함량에 큰 영향을 미쳤으며, 전지분유의 함량은 전지분유의 친수성 및 수용성 특성에 의하여 유변학적 특성의 변화에 영향을 미쳤다. 매쉬드 포테이토의 유변학적 특성 및 다양한 배합비에 따른 특성은 모델링을 통하여 구조적 및 성분에 따른 경향을 정량적으로 나타낼 수 있었다. 본 연구를 통하여 적색도와 안토시아닌의 함량을 최대로 함유하면서 유변학적 특성은 시판되는 매쉬드 포테이토와 유사한 고품질의 기능성 매쉬드 포테이토의 최적 배합비는 PFPP 90.49%, 전지분유 4.86%, 덱스트린 4.65%임을 도출하였다.

• 한국식품과학회지
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• 제31권2호
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• pp.348-355
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• 1999

자색감자의 anthocyanin 색소의 안정성에 대한 pH, 당, 유기산, 금속이온, ascorbic acid 및 광의 영향을 조사하였다. 자색감자 색소는 pH가 낮을수록 anthocyanin 색소의 안정성이 증가하였으며 pH가 높아질수록 색소 용액의 최대흡수파장이 장파장 쪽으로 이동하는 bathochromic shift현상이 관찰되었다. 당류 첨가는 오히려 무첨가구에 비해서 저장 안정성을 저하시켰는데 maltose, sucrose, galactose, fructose, glucose 순으로 안정성이 저하되었다. 유기산은 anthocyanin 색소의 안정화에 크게 기여하였으며 그 순서로는 malic acid, tartaric acid, citric acid, succinic acid 순으로 나타났고 malonic acid는 오히려 안정성을 떨어뜨렸다. 금속이온은 $Cu^{2+}$을 제외하고는 anthocyanin 색소의 안정화에 기여하였으며 특히 $Cd^{2+},\;Al^{3+}$이 효과적이었다. Ascorbic acid는 anthocyanin 색소의 파괴를 초래하여 안정성을 저하시켰으나 thiourea를 첨가하므로 색소파괴의 정도를 낮출 수 있었다. 일광에 의해 anthocyanin 색소의 파괴가 촉진된 반면 광을 차단할 경우 색소를 안정화시킬 수 있었다.