• Journal of the East Asian Society of Dietary Life
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• v.15 no.2
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• pp.207-212
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• 2005

To determine changes of chlorophyll and potato glycoalkaloid(PGA) contents in potato tubers after lightening, Dejima potatoes cultivated in Korea were used and PGA was analyzed by HPLC. Potatoes were stored under fluorescent and UV light exposure or darkness for 7 days at $5^{\circ}C$. The contents of chlorophyll and glycoalkaloid in the peel of potatoes exposed to fluorescent light were increased to $84\%,\;69.5\%$ respectively compared to potatoes stored without lightening. While a marked effect of lightening on the peel of potatoes exposed to fluorescent light, UV light lead to no change of chlorophyll and less increase in glycoalkaloid than fluorescent did. The increase of chlorophyll was provoked by only fluorescent light. Cortex part did not accumulate any chlorophyll or glycoalkaloid.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.5
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• pp.600-606
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• 2006

This survey was conducted to investigate the usage of potato and recognition of glycoalkaloid among residents aged from their teens to over fifties in Daegu city and Gyeongbuk Province. The preferred purchase places for the respondents were traditional markets (41.8%), big discount markets (23.8%), and supermarkets (14.9%), in order. Freshness (52.1%) was the most important criterion followed by size (12.5%), sprout (10.1%) and producing district (6.6%), in order. Most (77.6%) respondents preferred small amount below $2{\sim}3kg$ per purchase. Potato recognition revealed that respondents knew relatively well that potato sprouts contain toxins (M=4.30), that the major potato toxin is solanine (M=3.86) and that potato contains toxins when its color turns to green (M=3.70). However, respondents did not recognized well that the potato peel contains toxins (M=3.00), or that this toxin is chaconine (M=2.48).

• Journal of the Korean Home Economics Association
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• v.42 no.4
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• pp.187-194
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• 2004

The concentration of potato(Solanum tuberosum L.) glycoalkaloids(PCA) (i.e., ${\alpha}$-chaconine and ${\alpha}$-solanine) in Korean cultivated potato plant, and in the different varieties, parts and weights of the potato tubers, were determined by high-performance liquid chromatography(HPLC). The highest concentrations of PGA in potato plants were found in the roots, followed by the stems and leaves. A large quantity of PGA existed in the periderm of 'Atlantic' potatoes, whereas 'Irish Cobbler' contained the lowest amount in five cultivated potato tubers.'Irish Cobbler' potatoes were divided into three parts and the PGA content in each part was determined. It was found that both of the end parts of the potatoes contained higher PGA than the middle part. The PGA contents in four different sizes of potatoes increased toward the smaller size. Thesignificantly high level of PGA was contained in the smallest size potato tubers, which have been used widely for Korean cooking.

• Korean journal of food and cookery science
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• v.20 no.1
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• pp.76-80
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• 2004

The potato tubers of Solanum tuberosum L. contain potato glycoalkaloids (PGA), a class of naturally occurring toxicants. The primary constituents of this class of compounds in potatoes are $\alpha$-chaconine and $\alpha$-solanine. The purpose of this study was to examine the effects of various cooking methods on the PGA contents in the common Korean potato Irish Cobbler variety and those in commercially produced potato products consumed in Korea. After cooking, most potatoes showed big decreases in their PGA contents compared to the uncooked samples, with the exception of baked potatoes, which maintained 90.86％ of their PGA contents. The PGA levels in boiled and blanched potatoes were reduced by 91.68 and 84.17％, respectively. However, the levels in samples boiled in 1％ salted water were only reduced by 52.10％. Potatoes fried and sauteed in oil had their PGA contents reduced to 49.42 and 49.51％ of their original levels. The reductions in the relative PGA contents by cooking method were in the order boiling〉blanching〉boiling with 1％ NaCl〉steaming〉sauteing〉frying〉microwaving〉baking. The highest remaining PGA content of the potato products in Korea was in potato chips, at 69.57mg/100g, but made with imported potatoes.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.383-387
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• 1984

The difference of glycoalkaloids content on various parts of May Queen and Irish Cobbler potatoes was determined. ${\alpha}-Chaconine$ and ${\alpha}-Solanine$ were isolated from the glycoalkaloids by use of high performance liquid chromatography. It was found that the 99% of the total glycoalkaloids was existent in cortex part of all varieties. Glycoalkaloids content was higher in apical or basal part than the middle part. ${\alpha}-Chaconine$ content of the cortex showed no differences among parts of the potato in both varieties. ${\alpha}-Solanine$ was not detected in medulla part. The potatoes were classified into 4 groups depending on the weight and the glycoalkaloids content of the middle part. As the weight of the potato decreased the glycoalkaloids content of cortex part increased. Glycoalkaloids content was lower in medulla part and no constant tendency was observed.

• Korean journal of food and cookery science
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• v.20 no.6 s.84
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• pp.607-613
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• 2004

The purpose of this study was to investigate the quality characteristics of functional cookies made with potato peels (cortex layer) containing high amounts of glycoalkaloid. Cookies were processed by mixing ratios of 10, 15 and $20\%$ potato peel relatively to flour. The spread ratio of the cookies was increased with increasing potato peel addition. Texture measurement for the cookies on substituting $10\%$ of flour for potato peel showed a decreased hardness, but the cohesiveness and springiness were increased compared to the control and other ratios. The glycoalkaloid contents of the cookies on substituting 10, 15 and $20\%$ of the flour forpotato peel were 6.27, 9.40 and 12.54mg, respectively, which according to the USAD guidelines are safe amounts for the human body, and also enough for making functional cookies. In the sensory evaluations, the cookies with $10\%$ of the flour substituted for potato peel had the highest scores in flavor, taste, appearance and texture.

• Korean journal of food and cookery science
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• v.21 no.1 s.85
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• pp.12-17
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• 2005

The purpose of this study was 10 investigate the quality characteristics of potato added functional cream soup. The highest crude protein (p<.01) and crude lipid (p<.001) were for the potato soup with added potato peel ($S_3$). The highest pH of 5.95 was for the potato soup with added potato peel ($S_4$). The highest lightness of 69.46(L value) was for the potato soup with added potato peel ($S_3$) (p<.01). The redneess(a value) and yellowness(b value) were increased by the adding of potato peel to the potato soup(p<.01). Viscosity was increased by potato content, and was the highest for the potato soup ($S_2$) (p<.001). The glycoalkaloid content of the potato soup with added potato peel was 1.75 mg and 2.20 mg, for $S_3$ and $S_4$ respectively. In sensory evaluation, the highest sensory scores for flavor and taste (p<.05) of mean 3.55 and 3.45, respectively, were obtained from the potato soup with added potato peel ($S_4$). The highest overall acceptability of mean 3.00 was for the potato soup with added potato peel ($S_3$) (p<.01).

• Korean journal of food and cookery science
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• v.23 no.2 s.98
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• pp.245-251
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• 2007

The purpose of this study was to examine how potato glycoalkaloid(PGA) contents changed as storing temperatures and periods changed for potatoes(Superior) cultivated in Korea. Some potatoes were stored at $5^{\circ}$C for 80 days, and others were stored at $20^{\circ}$C for 40 days. PGA contents were measured every 20 days for the potatoes stored at $5^{\circ}$C and 10 days for those stored at $20^{\circ}$C. The results can be summarized as follows. The amounts of a-chaconine and a-solanine measured on the first day of storage were 54.22 mg/100 g and 26.57 mg/100 g, respectively. Thus, the a-chaconine content was almost twice as much as the a-solanine content. The sprouts of potatoes stored at $5^{\circ}$C grew by 0.4 cm in 20 days, 1 cm in 40 days, 1.8 cm in 60 days, and 5.2 cm in 80 days. Furthermore, the PGA content increased by 3.5% in 20 days, 11.6% in 40 days, 23.4% in 60 days, and 41.4% in 80 days, compared to the PGA content on the first day. The sprouts of potatoes stored at 20 grew by 0.5 cm in 10 days, 2.3 cm in 20 days, and 7.4 cm in 40 days. Furthermore, PGA content increased by 12.5% in 10 days, 36.6% in 20 days, 44.8% in 30 days and 48.4% in 40 days, compared to the PGA content on the first day. Thus, we determined that potatoes stored at $20^{\circ}$C showed faster sprout growths and faster increases in PGA content than those stored at $5^{\circ}$C.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.924-929
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• 2004

Quality characteristics of functional bread added with different concentrations of potato juice and processed by basic formulation were investigated. Specific volume and baking loss of bread added with 20% potato juice (potato juice : water = 20 : 80) were the highest. Moisture and crude protein contents increased with increasing content of potato juice, while crude lipid content decreased. Lightness (L value) and yellowness (b value) of bread decreased with increasing content of potato juice, while redness (a value) increased. Texture measurement showed springiness, cohesiveness, and brittleness increased with increase of potato juice content. Highest sensory scores for color (p < 0.001), flavor, and taste (p < 0.05) were obtained from bread added with 20% potato juice, while appearance (p < 0.01) and texture (p < 0.01) of control bread were highest. Glycoalkaloid contentsof bread added with 50 and 100% potato juice were 2.85 and 5.79 mg%, respectively.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1995.06b
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• pp.55-75
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• 1995

Induction of HMG-Co A reductase (HMGR) is essential for the biosynthesis of sesquiterpenoid phytoalexins and steroid derivatives in Solanaceous plants following wounding and pathogen infection. To better understand this complex step in stress-responsive isoprenoid synthesis, three classes of cDNAs for HMGR (hmg1, hmg2, and hmg3) were isolated from a potato tuber library. The potato cDNAs had extensive homology in open reading frames but had low homology in the 3'-untranslated regions. RNA gel blot analysis using gene-specific probes revealed that hmg1 is induced by wounding but wound induction is strongly suppressed by arachidonic acid or by inoculation with Phytophthora infestants. In contrast, hmg2 and hmg3 are slightly induced by wounding and strongly enhanced by arachidonic acid or inoculation. The induction and suppression of HMGR genes parallel the suppression of steroid and stimulation of sesquiterpenoid accumulations observed in earlier investigations. Treatment of the tuber disks with a low concentration of methyl-jasmonate doubled the wound induced accumulation of hmg1 transcripts and steroid-glycoalkaloid accumulation, but did not affect the abundance of transcripts for hmg2 or hmg3 nor induce phytoalexins. High concentration of methyl-jasmonate suppressed hmg1 mRNA and steroid-glycoalkaloid accumulation, induced hmg3 mRNA, and did not elicit phytoalexins. Lipoxygenase inhibitors suppressed the accumulation of of hmg1 transcripts and steroid-glycoalkaloids, which were restored by exogeneous methyl-jasmonate. Methyl-jasmonate applied together with arachidonic acid enhanced the elicitor induced accumulation of sesquiterpenes and sustained steroid-glycoalkaloid levels with transcript levels for the various HMGR mRNAs equal to or greater than wound-only treatment. These results domonstrate that the consequences of wound- and pathogen-responses of plants are different at the levels of gene expression and associated secondary metabolism.