• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.933-938
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• 2005

To investigate pertinent packaging treatment of fresh-cut potatoes (Solanum tuberosum L.), potato cubes were subjected to passive, gas exchange, and vacuum packaging conditions. Low density polyethylene film (LDPE), polypropylene film (PP), anti-fogging film (AP), and perforated film (PF) were used as passive packaging treatments. Mixed gases of 5% $CO_2/5%\;O_2$ (MA1) and 10% $CO_2/5%\;O_2$ (MA2) were applied as gas exchange packaging. Packs filled with cubes were kept at $5^{\circ}C$, and changes in weight loss, surface color, vitamin C content and sensory quality of cubes were analyzed during storage. Respiration rate of cubes was 2.11 times higher than that of intact raw potatoes at $5^{\circ}C$. Gas concentrations in passive packaging was maintained at 1-2% $O_2$ and 4-14% $CO_2$ after 7 days. Gas levels changed depending on films used. Cubes packed in PP and MA2 showed lowest weight loss and browning during storage. Firmness of cubes was not affected by packaging treatment. Vitamin C content was highest in cubes packed with AF. Cubes packed in MA2 showed highest quality upto 10days storage, followed by those packed in PP and AF.

• Food Science and Preservation
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• v.18 no.3
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• pp.414-422
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• 2011

The optimum condition for phenolics contents extraction from purple sweet potato was 12 hrs. in 50% ethanol. The electron donating scavenging activities (DPPH), ABTS radical cation decolorization (ABTS) and antioxidant protection factor (PF) of Jami, Yeonjami and Shinjami were higher than general sweet potato, and thiobarbituric acid reaction substance (TBARs) was below 30%. The minimum inhibitory concentration (MIC) against Staphylococcus aureus and Escherichia coli on skin were each 5,000 and 2,500 ppm in all purple sweet potatoes, and MIC of Jami was the lowest as 2,500 ppm against Staphlococcus epidermidis. The whitening (tyrosinase inhibitory) activity of purple sweet potatoes was the highest as 62.5% and 48.7% in Jami water and ethanol extracts. The anti-inflammation (hyaluronidase inhibitory) activity of purple sweet potatoes was the highest as 25.3% and 94.4% in Jami water and ethanol extracts. The safety of cosmetic with Jam; extracts was assessed by various safety profiles. pH and viscosity change of essence for 90 days was not detected. Cosmetic was stable to temperature and light for 90 days. The result to measure changes of skin color and pore size of the skin was that an aged skin was more effective than young skin.

• Food Engineering Progress
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• v.21 no.2
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• pp.167-173
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• 2017

Purple-fleshed potato powder (PFPP) was investigated to determine optimal mixing ratio with milk powder and dextrin to produce a ready-to-eat mashed potato powder. The rheological characteristics, color, and anthocyanin contents were studied at a different concentration of ingredients. The power-law model was applied to explain the mechanical spectra of mashed potatoes which represented the change in structure induced by different mixing ratios. Mixture design was used to obtain the experimental points used to establish the empirical models to describe the effects of each ingredient on the characteristic of the mashed potato. The results of mechanical spectra showed that both storage and loss moduli (G' and G'') were significantly influenced by PFPP and milk powder concentration. The power law parameters n' and n'' showed higher values for the mashed potato with a lower concentration of PFPP and a higher concentration of milk powder, which showed that the gel networks involved in the mashed potato were weaker. The optimum mixing ratio with the highest redness and anthocyanin content, while maintaining the rheological properties similar to the commercial mashed potato, was determined as PFPP:milk powder:dextrin = 90.49:4.86:4.65 (w/w). The proportions of PFPP and milk powder in the formulation significantly changed the characteristics of mashed potato, whereas no significant effect of dextrin was observed in this formulation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.436-446
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• 2020

In this study, we verified the effects of organic amendment application based on soil testing in potato cultivation. The application rate of organic amendments was determined based on the inorganicization rate of nitrogen, phosphoric acid, and potassium in the organic amendments. There was no significant difference in the length, stalk number, stalk diameter, and leaf color of potato plants under organic amendment application compared with those under chemical fertilization. The quantity of potato tubers and yield of marketable tubers under organic amendment application were higher than those under chemical fertilization. The top fresh weight and top-to-root ratio were the highest under organic amendment application, followed by those under chemical fertilization and the control. The inorganic nitrogen content in the leaves and stems of potato plants was the highest under chemical fertilization. There was no difference in the phosphoric acid content between the potatoes under chemical fertilization and those under organic amendment application. The potassium content in potatoes was higher under chemical fertilization than that under organic amendment application. While the change trend of inorganic nitrogen content in the roots was similar to that in the leaves and stems, the potatoes under organic amendment application, with the highest yield, showed the highest dry weight. The tuber weight showed a positive correlation with plant length, stalk number, and stalk diameter. The higher the weight of the tuber, the higher the weight of the marketable tuber, and the higher the top fresh weight, the higher the yield. Therefore, to increase yield, it is necessary to supply nutrients to improve the top fresh weight to the optimal level. There was no difference in the utilization efficiency of nitrogen and potassium between the potatoes under chemical fertilization and those under organic amendment application. The utilization efficiency of phosphoric acid was increased by 0.1% in potatoes under organic amendment application compared with that under other treatments. Regarding soil chemistry after harvest, the soils under organic amendment application showed a higher electrical conductivity and higher nitrogen and phosphoric acid content than those under other treatments. Therefore, the organic amendment method used in this study can be an alternative to chemical fertilization. It is also advantageous for the cultivation of subsequent crops in potato fields.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.124-130
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• 2020

The sweet potato (Ipomoea batatas [L.] Lam.) is the sixth-most important crop in the world following rice, wheat, potato, maize, and cassava. Four varieties ('Beniharuka', 'Annobeni', 'Pungwonmi', 'Hogammi') and their Japanese cultivars are broadly distributed in South Korea. In the Korean marketplace, sweet potatoes are classified by color and shape, not by variety, making it necessary to differentiate varieties for uniform production and consumption. In this study, molecular markers were developed to distinguish the four varieties of sweet potato using SNPs and genotyping-by-sequencing (GBS) analysis via a tetra-primer amplification refractory mutation system (ARMS)-PCR. The results revealed that three variety-specific fragments (164 bp and 241 bp of SNP 04-27457768 and 292 bp of SNP 03-16195623) were amplified in the 'Beniharuka', 'Pungwonmi', and 'Annobeni' sweet potato varieties. There were instances where some varieties produced three bands within the gel electrophoresis, indicating heterozygosity at the given SNPs loci. DNA sequencing analysis also confirmed the results of electrophoresis at the SNPs loci. Overall, these molecular markers would provide a useful, rapid, and, simple evaluation method for the Korean sweet potato marketplace, where the mixing of varieties is a serious issue.

• Journal of the Korean Magnetic Resonance Society
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• v.26 no.3
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• pp.24-33
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• 2022

The browning phenomenon of fruits can be easily observed when fruits or vegetables (apples, pears, bananas, potatoes, etc.) are cut with a knife and the part turns brown. When this browning occurs, changes in taste, color, and nutrients usually are introduced. The cause of this browning phenomenon has been well studied for a long time, but these studies have mainly focused on preventing deterioration of processed foods during food processing or storage. Resultantly, there are few studies on how much changes in nutrients (saccharides, amino acids, fats, water-soluble low molecular weight ammonium ions, etc.) are caused by browning. The purpose of this study is to determine the change in nutrients during browning using apple as a model fruit. We conducted a comparative study on how much the nutrient fluctuations differ depending on the presence or absence of pretreatment such as the application of heat. All analysis was conducted using ¹H NMR. The ANOVA analysis showed that the concentrations of 4 amino acids (alanine, asparagine, isoleucine, and valine), 3 types of sugars (fructose, glucose, and xylose), 1 type of organic acid (lactate) and choline were significantly increased in samples showing browning. In addition, the groups before and after browning were clearly separated using multivariate statistical analysis methods (PCA, PLS-DA), which was greatly contributed by two sugar components (fructose and glucose) present in high concentrations in apples.

• Journal of Applied Biological Chemistry
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• v.58 no.1
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• pp.21-24
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• 2015

Antioxidant activities of ethanol extracts from three types of sweet potatoes with distinctive flesh color (white, orange, and purple) were investigated. Total phenolic content of purple-fleshed sweet potato (PF) was always 2- to 5-fold higher than those of white-fleshed (WF) and orange-fleshed sweet potato (OF). 2,2-diphenyl-1-picryl-hydrazyl free radical scavenging activity of 70% ethanol extracts was highest ($EC_{50}$ = 0.179 mg/mL) for PF and lowest ($EC_{50}$ = 2.127 mg/mL) for OF. And then, reducing power was also highest ($EC_{50}$ = 0.236 mg/mL) for PF and lowest ($EC_{50}$ = 1.587 mg/mL) for WF. Antioxidant activities of 70% ethanol extracts were closely related to the amount of total phenolics. These results imply that antioxidant activity of PF is 6.7 to 11.9 times higher than those of WF and OF.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.144-150
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• 2011

This study was conducted to investigate the nutrient components and physicochemical properties of general ('Superior') and colored potato. Proximate composition, reducing sugar, free sugars, free amino acids, organic acids, minerals were analyzed, and Hunter color values were measured in the study. 'Rose' and 'Blue' (colored potatoes) contained high levels of reducing sugar, and total free sugar content was greatly different according to varieties. Glutamic acid, arginine and ${\gamma}$-aminobutyric acid were detected to be the three major amino acids in colored potato, and the major organic acids of general potato were oxalic acid, tartaric acid, malic acid and citric acid. All potato contained high level of potassium, calcium and magnesium. The Hunter 'L' value was the highest in 'Jaseo'; Hunter 'a' value was high in 'Blue' and 'Jasim'; Hunter 'b' value was the highest in 'Haryoung'. Overall, colored potato had higher amount of nutrients and physicochemical properties than 'Superior'. Therefore, colored potatoes are expected to be highly valuable items for the development and applications of a functional food. In addition, these results will provide fundamental data for improving sitological value, breeding of new cultivar and promoting of roughage usage.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.247-254
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• 2005

General composition, total anthocyan content, and antioxidative and antimicrobial activities of Korean purple. fleshed potatoes (varieties A-D based on coloring degree of cross sections) were investigated. Slight differences in composition content were observed among varieties. Color intensity analyzed by sensory evaluation test decreased in order of PL-14, 31, 28, 3, 17, and 6, Total anthocyanin contents differed significantly among varieties from 3 to 29 mg Per 100 g, and decreased in order of PL-28, 31, 14, 12, 5, and 3. PL-28, 31, and Jasim potatoes showed slightly higher antioxidant activities than ${\alpha}$-tocopherol. PL-28, 31, 6, and Jasim showed antimicrobial activities against three species each of Gram-positive and-negative bacteria, with highest activities observed against Bacillus subtilis and relatively high activities against E. coli.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.261-265
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• 2003

In order to examine the difference in processing quality of potato tubers among localities, chemical properties of soils were analyzed and climatic conditions were investigated. Potatoes (Solanum tuberosum L.) were grown at seven localities of Korea during two years from 1994 to 1995. Soil samples and tubers were obtained from 2 to 3 commercial farms per locality with 10 days interval from 70 days before harvesting. As the result of that, higher correlation in processing quality was found with organic material content among soil conditions. On the climatic conditions, minimum temperature and sunshine hours during the period from 30 to 11 days before harvesting exhibited highly significant negative correlations with all quality parameters except reducing sugar content. Additionally, regression equations based on the observed level of these factors showed the relatively high coefficients of determination for dry matter content and chip color. To produce higher quality potatoes for processing, therefore, climatic conditions such as minimum temperature and sunshine hour and soil condition such as organic matter content have to be considered before the selection of areas or fields.