• Korean Journal of Agricultural Science
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• v.38 no.3
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• pp.405-411
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• 2011

In this study, we evaluated the changes of fruit quality indices during fruit development and ripening in Korean new pear cultivar 'Wonhwang' and 'Whasan' to determine appropriate harvest time and to enhance the marketability. The fruit of each cultivar harvested from 100 days after full bloom (DAFB) to 135 and 150 DAFB in 'Wonhwang' and 'Whasan', respectively. The fruit growth of both cultivars showed a typical single sigmoidal pattern. Flesh firmness of two cultivars decreased continuously with fruit development and ripening, reaching a final level of about 2.6 kgF at harvest stage. The starch content of fruit sap was much higher in the fruits of early development stage than the later stage of fruit ripening. In 'Wonhwang' pears, the starch level decreased coincide with fruit ripening (130 DAFB), while that of 'Whasan' decreased from very early stage of fruit development (120 DAFB), 30 days before full ripe. 'Whasan' pear showed much lower acidity level of about 0.13% during fruit development and ripening period compared with that of 'Wonhwang'. Therefore, the ratio of soluble solids to total acidity (TSS/acid) increased gradually with fruit development and ripening, reaching a final level of 80 and 98 in 'Wonhwang' and 'Whasan', respectively. There were no climateric rise of fruit respiration during fruit ripening periods in two oriental pear cultivar. The changes of skin color difference including hunter vale $a^*$ which means loss of green color occurred only after onset of ripening in two cultivars.

• Korean Journal of Food Science and Technology
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• v.13 no.4
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• pp.334-339
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• 1981

Surface color, water extract color and soluble solids of the roasted barley resulted from the various roasting conditions were determined to establish the optimum roasting conditions. The correlation coefficients between the surface color of the roasted barley and its ground was in the range from 0.957 to 0.994, and which showed the internal color being well represented that of surface of the roasted grain. The degree of roasting was determined maim by the roasting temperature, rather than by the total heat energy input during roasting. The maximum yield of the water soluble solids was 68% and obtained from the barley roasted at $232^{\circ}C$ for 25 minutes. The readings of Y-value of the roasted whole barley was a good index to judge and control the degree of roasting.

• Current Research on Agriculture and Life Sciences
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• v.28
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• pp.53-62
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• 2010

The effect of far-infrared (FIR) irradiation on the functional compounds of grape seeds extract were evaluated. Grape seed was dried on different heating power (0, 900, 1800 W) and heating time (0, 20, 40 min) with far-infrared drier. Contents of soluble solids, catechins, total phenolics and total flavonoids along with Hunter's color value, electron donating ability (EDA) and nitrite scavenging activity were analyzed. The soluble solids, Hunter's L value and a value were not significantly different from control samples. Cathechin, procyanidin $B_2$ and epicatechin contents changed with heating time. In the treated sample, total cathechins content was found maximum at 900 W of heating power and 20 min of heating time with a high level of total phenolics, total flavonids and EDA. These results indicated that FIR irradiation of grape seed could enhance antioxidant activities of its extracts by increasing the amounts of functional compounds. Moreover, response surface methodology(RSM) was applied to predict optimum conditions for heating by FIR rays of grape seeds. Based on superimposition of contour map with respect to total phenolics, total catechin and EDA, optimum ranges of heating conditions were heating power of 621.82~818.18 W and heating time of 16.3~19.83 min.

• Food Science and Preservation
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• v.3 no.2
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• pp.105-111
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• 1996

The conditions of cold stroage of Citrus unshiu Marc. var. okitsu produced in Cheju were investigated. The changes of peel moisture contents soluble solids, total sugar, vitamin C and density were slightly occured, and decay ratio was below 20% on keeping freshness relatively till late of March during cold storage. After thats decayed citrus fruits were increased gradually mainly from cold injury with lower temperature and high humidity. The loss of fruit weight, decrease of fruit hardness, and decrease of acid content were occured gradually during cold stroage. Because of the difficulty of long term storage for Citrus unshiu, the conditions and periods of cold storage would be determined after considering the physicochemical properties of fruits every year.

• The Korean Journal of Food And Nutrition
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• v.34 no.1
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• pp.15-25
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• 2021

This study aimed to investigate the antioxidant activities and quality characteristics of jelly added with Orostachys japonicus juice. The moisture content and the soluble solids content of the jelly samples decreased significantly with increasing content of O. japonicus. The pH was highest in the control samples, and the pH significantly decreased with the addition of increasing amounts of O. japonicus. In terms of the chromaticity measurements, the lightness value and redness value was highest in the control sample, and it decreased as the amount of added O. japonicus increased, whereas the yellowness value increased with increasing levels of O. japonicus added. The gumminess and chewiness of the jelly increased with the addition of increasing amounts of O. japonicus. On the other hand, the cohesiveness and adhesiveness of the jelly did not show statistically significant changes. The total polyphenol and DPPH radical scavenging activities of the jelly with 100% O. japonicus added were significantly higher than those of the jelly with 0% O. japonicus added. Regarding the sensory evaluation, the sample with 75% O. japonicus added was perceived to have the best color, flavor, O. japonicus flavor, chewiness, and overall preference.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.668-674
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• 1990

Tempeh-type fermented products were prepared from soybean, sorghum or mixture of soybean and sorghum(1 : 1) with the traditional Indonesian inoculum(LARU : mixed cultures of Rhizopus oligosporus). Fermentation increased protein and fiber contents in the soybean tempeh(ST) and tempeh of soybean-sorghum mixture(SSM). Fat content was slightly higher in sorghum tempeh(SGT) and SSM than that of control. During the fermentation, pH, soluble solid and soluble nitrogen were increased, while no significant change was found in the total solids. The trypsin inhibitor activity(TIA) and phytic acid content decreased after 32 hrs fermentation. It is suggested that Rhizopus oligosporus is capable of hydrolyzing trypsin inhibitor and phytic acid of the substrate. Thiamine and niacin contents increased in all samples as compared with the unfermented control. In amino acid level, there were some decreased in total amino acids after 32 hrs fermentation in three types of tempeh. While the concentrations of lysine, valine. tyrosine and alanine in ST, SGT and SSM were increased those of serine and glutamic acid were decreased in compare to the unfermented control.

• Food Science and Preservation
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• v.30 no.2
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• pp.190-204
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• 2023

Because of their short harvest season, large quantities of persimmons must often be processed within a limited time. Therefore, new methods to extend their storage life are required. This study examined the effects of chlorine dioxide (ClO₂) gas fumigation for various treatment periods on the storage quality of astringent persimmons Cheongdobansi under low-temperature conditions. The conditions consisted of continuous treatment with ClO₂, treatment for 2 weeks with ClO₂, and no treatment, all of which are stored at low temperatures. Control samples (storage 0 days) without any treatment were prepared and all experiments were conducted for 10 weeks at two-week intervals. The ClO₂ gas treatment maintained the moisture content, color value, hardness, soluble tannin content, and sensory characteristics. However, ClO₂ gas treatment did not affect the soluble solids, pH, and total sugar content. In particular, continuous treatment with ClO₂ maintained the storage quality after 6-8 weeks of storage, particularly the hardness and weakness (sensory evaluation). The results suggest the potential of continuous treatment with ClO₂ as a highly effective method for maintaining the freshness of Cheongdobansi.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.171-177
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• 2005

Nutritional compositions and antioxidative activity of Kabocha squash (Cucurvita maxima Duch) as health food were compared with those of pumpkin (Cucurvita moschata Duch). Kabocha squash had higher soluble solids and twofold harder flesh than pumpkin. Crude protein, crude lipid and total amino acid contents of Kabocha squash were higher than those of pumpkin. Major free sugar in Kabocha squash was sucrose, and its content were 2.1 times higher than that of pumpkin. Major organic acids of Kabocha squash and pumpkin were succinic and malic acid, respectively. Kabocha squash had higher amounts of vitamins $A,\;B_1,\;B_2,\;C$ and C than pumpkin, while both showed similar mineral contents except for iron. Contents of Total pectin and hydrochloric acid soluble pectin of Kabocha squash were 17.00 and 7.37 g/100 g AIS, respectively. In pumpkin, total pectin content was 25.14 g/100 g AIS, and water soluble pectin content was higher than those of other pectin fractions. Contents of carotenoid in Kabocha squash and pumpkin were 285.91 and 24,62 mg% d.b., respectively. Kabocha squash had higher electron-donating radical-scavenging activity, SOD-like activity and nitrite-scavenging effect than pumpkin.

• Food Science and Preservation
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• v.23 no.2
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• pp.155-161
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• 2016

This study aimed to investigate the effects of pretreatments blanching, roasting, drying, and storage temperatures ($25^{\circ}C$, $4^{\circ}C$ and $-10^{\circ}C$) on their quality of lotus leaves. As a result, the lotus leaves retained a good appearance when stored at $25^{\circ}C$ for 5 days, $4^{\circ}C$ for 30 days, and $-10^{\circ}C$ for 90 days, regardless of the pretreatment used. At the same storage temperatures, pH, soluble solids, total acid content, polyphenols, and microorganisms were significantly different among the pretreatments (p<0.05). Soluble solids, pH, and total acid contents were not significantly different for the same pretreatments at different storage temperatures. However, the polyphenol, oxalic acid, and tartaric acid contents of lotus leaves were significantly different after drying and blanching treatments. In particular, it was shown that polyphenol content of the lotus leaf was affected by both pretreatment and storage temperature. In conclusion, the lotus leaves appeared in good condition until 5 days at $25^{\circ}C$, 30 days at $4^{\circ}C$, and 90 days at $-10^{\circ}C$, regardless of the pretreatment while influenced by storage temperature.

• Korean Journal of Food Science and Technology
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• v.51 no.1
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• pp.35-41
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• 2019

The sensory characteristics of eight commercial ready-to-drink (RTD) cold brew coffees were compared by descriptive analysis. The cold brew coffee samples were analyzed for hunter color values, brown color, turbidity, pH, titratable acidity, soluble solids, total phenolic content, and chlorogenic acid content. Three appearances, nine aroma, five flavor/taste, and four texture/mouth-feel related sensory attributes were evaluated by a panel of nine judges. The results of three-way analysis of variance of descriptive data showed that all sensory attributes except "fruit" aroma, "dark chocolate" aroma, "bitter" aroma, and "sweet" taste had significant differences among the samples (p<0.05). Based on the principal component analysis (PCA) of the descriptive data, the samples were primarily separated by first and second principal components, which accounted for 81.78% of the total variance among the samples with high intensities of "nutty aroma", "grain aroma", and "grain taste" versus "earth aroma", "sour aroma", "sour taste", "astringent", "smoothness", and "residual". In the correlation analysis of sensory terms and physicochemical parameters, titratable acidity and soluble solids showed significant positive correlations with earth aroma and smoothness characteristics.