• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.1
• /
• pp.72-84
• /
• 1993

This study was carried out to understand the varietal variation in physicochemical properties of rice grain and those environmental changes by different transplanting time, and to elucidate the interrelationships among the factors related with eating quality of cooked rice. Fifty three rice samples, among which fifty samples were harvested at ordinary or late transplanted plots of the Crop Experiment Station in Suwon and three samples were harvested orpurchased from Niigata prefecture in Japan, were tested for various physicochemical components of rice grain and some physical factors of cooked rice. All of twenty seven rice cultivars tested were the recent-bred Korean japonica rice showing the wide range of maturity from early to medium-late heading and considerable difference in palatability of cooked rice. Amylose content, taste value by Nireco palatability tester (TVN), iodine blue color of cooking extracts(IB), and the ratio of IB /extracted solid amounts (ES) increased significantly by late transplanting, while viscosity (VN) and Mg / K. N value by Nireco tester, hot-water absorption of milled rice (HA), loss tangent of cooked rice by Rheolograph-Micro(LT), and most viscogram characteristics except setback viscosity (C-P) decreased drastically by late transplanting as compared with ordinary transplanting. Most of physicochemical properties of milled rice revealed narrower varietal variation in lately transplanted plot than in ordinary transplanted one. Protein content (PRO), volume expansion rate of cooked rice(VE), C-P and all physical factors of cooked rice by Rheolograph-Micro showed almost negligible seasonal variation, while amylose content (AM), VN, HA, IB/ES, peak viscosity(P), hot viscosity(H) and breakdown(P-H) viscosity exhibited considerably large seasonal variation. The early-headed varieties revealed lower amylose content and smaller seasonal variation of IB/ES compared with medium or medium-late headed rice varieties. AM was closely associatied with IB and IB / ES and VN was highly correlated with Mg/K. N and TVN in both ordinary and late transplanted plots. VN also was highly negatively correlated with cooking characteristics and highly positively correlated with viscogram properties in ordinary culture. PRO was closely connected with moisture content of milled rice and L T in ordinary transplanted plot. IB, which was closely connected with ES, was also singificantly associated LT, P and P-H in ordinary seasonal culture. IB/ES was highly negatively correlated with P, P-Hand P-H / C-P in ordinary culture but with LT and dynamic viscosity of cooked rice in late seasonal culture. The thirty rice cultivars were largely classified into two varietal groups by cluster analysis with physicochemical properties related with eating quality of cooked rice. Korean and Japanese high-quality rice cultivars were separately distributed in two respective varietal group.

• Korean Journal of Food Science and Technology
• /
• v.16 no.1
• /
• pp.71-77
• /
• 1984

A study on the stability of chlorophyll a in Undaria pinnatifida during blanching, salting and storage was carried out. Raw Undaria pinnatifida was blanched for 25 seconds in the temperature range of 70 to $100^{\circ}C$. To stabilize the chlorophyll a some chemicals such as 1% solutions of $Ca(CH_3CO_2)_2,{\;}Ca(OH)_2,{\;}MgCO_3,{\;}0.5%{\;}Ca(CH_3CO_2)_2$ with $0.5%{\;}MgCO_3$, and reed ash solution were used during/after blanching. The blanched product was salted with table salt after centrifuging for 2 minutes at 1500 rpm, and then again centrifuged after 48 hours for dewatering. The product which was mixed with 8% of table salt was sealed in a polyethylene film bag and stored at 10, 20, 30 and $40^{\circ}C$. The most effective blanching temperature for maximal residual amount of chlorophyll a was $85^{\circ}C$. The quantities of total organic and volatile acids were not significantly changed by the blanching temperature. Blanching in 1% chemical solutions showed bitter results than soaking in 1% chemical solutions for 20 minutes after blanching without chemicals. Reed ash and 0.5% $Ca(CH_3CO_2)_2$ with 0.5% $MgCO_3$ solutions were more effective than the 1% solutions of other chemicals, but the effect was not significant, compared with the group not treated with chemicals. The most reasonable ratio of added salt to dewater the product for 48 hours was 30% in w/w. The amount of total organic and volatile acids revealed no correlation with the amount of added salt. Color and odor of salted product was not severely changed during the storage of 77 days at $10^{\circ}C$. But the changes were accelerated with increasing storage temperatures. The degradation of chlorophyll a in salted product during storage could be interpreted as a first order reaction, and the rate constants at 10, 20, 30 and $40^{\circ}C$ were 0.1289, 0.1028, 0.0770 and 0.0550, respectively. $Q_{10}$ and the activation energy were 1.33 and 5.01 Kcal/g mole.

• Journal of the East Asian Society of Dietary Life
• /
• v.18 no.5
• /
• pp.789-796
• /
• 2008

This study was carried out to investigate the effect of the addition of red wine on the color, water activity, hardness, pH, 2-thiobarbituric acid (TBARS) value, volatile basic nitrogen (VBN) content and total plate count of beef jerky during storage at room temperature for 4 weeks. Beef jerky was prepared using three variations: beef jerky containing 50 mL water (T0), beef jerky containing a combination of 25 mL water and 25 mL red wine (T1) and beef jerky containing 50 mL red wine (T2). The lightness ($L^*$) was the lowest at the 4-week storage period, and the $L^*$ value of T1 and T2 were lower than that of T0 (p<0.05). The redness ($a^*$) tended to decrease during storage, with the $a^*$ value of T1 and T2 being higher than that of the T0 (p<0.05). The yellowness ($b^*$) during storage was not changed, and the $b^*$ value was not significantly different among the different samples tested. The water activity decreased during storage and T0, T1 and T2 was 0.57, 0.57 and 0.60 after 4 weeks of storage, respectively(p<0.05). The hardness increased during storage and the hardness of T2 stored for 4 weeks was lower than that of T0 and T1 (p<0.05). The pH was decreased with an increase in storage time (p<0.05). The TBARS value increased during storage and the TBARS value of T1 and T2 stored for 4 weeks was lower than that of T0 (p<0.05). The VBN content increased during storage and T2 stored for 4 weeks showed the lowest (p<0.05). The total plate count tended to increase during storage, and T0 stored for 4 weeks showed the highest (p<0.05).

• Journal of the East Asian Society of Dietary Life
• /
• v.26 no.5
• /
• pp.435-444
• /
• 2016

This study was conducted to investigate the effects of natural preservatives (G3, G3-1, F3, and F3-1) using Cordyceps militaris on improvement of food quality and safety of noodle during storage. Wheat flour noodle were prepared using three different concentrations of natural preservatives (0.100, 0.200, and 0.400%). Changes in microbial populations, pH value, titratable acidity, and sensory evaluation were measured during storage at $12{\pm}2^{\circ}C$ for 3 days. Overall, use of natural preservatives resulted in lower levels of total mesophilic bacteria, coliform, yeast and mold in noodle compared to the control. In particular, natural preservatives using $2{\times}$ MIC concentrations (0.400%) of F3 and F3-1 were effective at maintaining levels of total mesophilic bacteria for noodle during storage. The pH values of noodle made with F3 and F3-1 were higher than the others. The titratable acidity of noodle with natural preservatives did not significantly change during storage. In sensory evaluation, appearance, color, and overall acceptability of noodle with F3 and F3-1 were preferred than the control. These results could provide useful information for developing an alternative preservation method to improve food quality and shelf-life of noodle using natural preservatives.

• Food Engineering Progress
• /
• v.21 no.3
• /
• pp.225-232
• /
• 2017

Most of the red ginseng (RG) products contain active substances derived from hot water or alcohol extraction. Since active substances of RG are divided into two types - water-soluble and liposoluble - water or alcohol is needed as an extraction solvent and this leads the different extraction yields and components of the active substances. To overcome the limit, whole red ginseng powder can be used and consumed by consumers. In this study, the physicochemical properties and extractable active substance contents of variable-sized RG powder ($158.00{\mu}m$, $8.45{\mu}m$, and $6.33{\mu}m$) were analyzed, and dispersion stability was measured to investigate the suitable size of RG powder for industrial processing. In the results, no significant difference was found from the changes in color intensity and thiobarbutric acid tests at $4^{\circ}C$, $25^{\circ}C$, and $40^{\circ}C$ for 4 weeks. There was no significant difference on the production of antioxidants and ginsenoside among the samples (p>0.05). In dispersion stability, $RG-158.00{\mu}m$ was precipitated immediately, and the dispersion stabilities between $RG-8.45{\mu}m$ and $RG-6.33{\mu}m$ showed no significant difference. It implies that fine RG is suitable for the production process. With further study, it seemed that the physicochemical effects of RG particle sizes can be clearly revealed.

• Journal of Bio-Environment Control
• /
• v.20 no.3
• /
• pp.233-240
• /
• 2011

We evaluated the changes of fruit quality factors and the incidence of physiological disorders during the periods of high temperature environment in 'Wonhwang' and 'Whasan' pears to determine appropriate harvest time for exportation. In 'Wonhwang' pears, the fruits harvested at 130 days after full bloom (DAFB) showed 31.3 and 17.6N of flesh firmness after 5 and 10 days after simulated marketing at $30^{\circ}C$, respectively, while those of the fruits harvested at 135 DAFB lowered to 16.7 or 6.9N, respectively. Whereas, 'Whasan' pear showed higher firmness during 14 days of high marketing condition than 'Wonhwang' pears which represented 30.4, 26.5 and 21.6N in the fruits harvested 145, 150 and 155 DAFB, respectively. Higher soluble solid contents and lower acidity values observed in the late harvested fruits in both cultivar along with increased marketing period at $30^{\circ}C$. Late harvested 'Wonhwang' pears showed higher respiration rate and ethylene production than early harvested ones, while those of 'Whasan' pears showed lower values regardless of fruit maturity which represented less than 50% of 'Wonhwang' pears. The incidence of physiological disorders such as internal browning, water soaking, flesh spot decay, core breakdown and pithiness appeared more severely in the fruits of 'Wonhwang' in accordance with the progress of high temperature marketing and fruit maturity. Whereas, those symptoms were occurred only after 14 days of prolonged marketing time in 'Whasan' pears. Consequently, it was needed to pay more attention to determine the ripeness when the fruits exported to the country with high temperature environment, especially in the fruits of 'Wonhwang' pears showing rapid quality loss and severe physiological disorders.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.8
• /
• pp.996-1002
• /
• 2009

This study was carried out to improve quality and increase anticancer effect of baechu kimchi by changing various kinds of salt. The baechu cabbages were brined with purified salt (P), natural sea salt (NS), natural sea salt without bittern (NS-B) or baked (Guwun) salt (G) and mixed with other ingredients. Thereafter, the kimchis were fermented for 7 days at $15^{\circ}C$. The changes in pH and acidity of the P and G kimchis were slower than those of NS and NS-B kimchis. NS-B and G kimchis promoted the growth of Leuconostoc sp.; however, it inhibited the growth of Lactobacillus sp. when compared with P and NS brined kimchis. The sensory evaluation results indicated that NS-B and G kimchis were better than P and NS kimchi in taste, color and overall acceptability. Rheological property of texture (cutting strength) of NS-B and G brined kimchis was also much better. Anticancer effects of the kimchi juices and methanol extracts were investigated on AGS human gastric adenocarcinoma cells and HT-29 human colon carcinoma cells by MTT assay. NS-B and G kimchis significantly retarded the growth of both cancer cells compared to P and NS kimchis. From these results, kind of salt is very important when kimchi is prepared. It proved that removing bittern from natural sea salt is good ancient tradition when brining the cabbage. Using the baked salt is also a better method to improve the quality and anticancer effect of kimchi.

• Horticultural Science & Technology
• /
• v.30 no.2
• /
• pp.214-219
• /
• 2012

This study aimed to develop a new type of functional citrus beverage (Citurs-F) containing flavonoids extracted from the young fruits of satsuma mandarin ($Citrus$ $unshiu$) and matured fruits of Jeju native dangyooja ($C.$ $grandis$). We made beverages that contained 30% of satsuma mandarin extract with different percentages of concentrated dangyooja-derived flavonoid extracts. In sensory evalution, the highest response indices of color, taste and aroma were from the beverages based on the 30% young fruit extracts plus 15% (Citrus-F-15) and 20% (Citrus-F-20) flavonoids extract from the dangyooja using the KILO prep. In the changes of body weight after oral administration of the Citrus-F, the rat group with HF diet plus the Citrus-F decreased the body weight compared to the rat group fed only HF diet. This effect was to be continued for 9 weeks until the end of experiment. In the lipid content in blood, the rat group with oral administration of citrus extractions merely tended to resolve it in serum test. However, all the 0.1% Citrus-F-15 and Citrus-F-20 treated rat groups from the beginning or after 5 weeks appeared the lowest lipid contents in the blood. In the cholesterol contents, the rat group feeding the KILO-prep's extraction from the beginning weren't significantly recognized them in the group but the rat group feeding 0.1% Citrus-F-15 acted to reduce in the cholesterol contents from 5 weeks. The results indicated that the Citrus-F-15 with rich flavonoids might be main source alleviating the vascular diseases and obesity in human diet.

• Journal of Korean Society of Forest Science
• /
• v.97 no.1
• /
• pp.35-44
• /
• 2008

Mycelial growth of Lentinula edodes on solid or liquid culture media supplemented with differentconcentrations of oak wood vinegar varied depending on the types of wood vinegar or mushroom varieties used.Oak wood vinegar obtained from traditionally carbonizing kiln (TWV) inhibited mycelial growth of L. edodes atthe dilution level of less than $5{\times}10^{-2}$, but stimulated at $10^{-3}$ to $2{\times}10^{-3}$. Wood vinegar from mechanicallycarbonizing kiln (MWV) inhibited at $10^{-3}$, but stimulated at $2{\times}10^{-3}$. In liquid culture media, both wood vinegarinhibited at $5{\times}10^{-2}$, but stimulated at $2{\times}10^{-3}$. Sanjo-302-ho grown in liquid culture media at $2{\times}10^{-3}$, and Sanrim 2and 3-ho grown at $4{\times}10^{-3}$ showed relatively high degree of wood decay (DWD) and growing ability within wood(GAWW) when these isolates were inoculated onto oak wood logs. TWV completely inhibited mycelial growth ofgreen mold fungi, Trichoderma species, tested at $5{\times}10^{-1}$ dilution level, while MWV inhibited at $5{\times}10^{-1}$ to $5{\times}10^{-2}$dilution level. For Diatrype stigma, TWV inhibited mycelial growth at the dilution level of less than $5{\times}10^{-2}$, whileMWV did 80% of mycelial growth at $10^{-2}$, and 100% at $5{\times}10^{-1}$ dilution level. Fresh and dry weight of fruitingbodies harvested after soaking of wood logs into wood vinegar solutions with different concentrations werecompared, and were the highest at $2.5{\times}10^{-2}$ dilution level. Storage test of fruiting bodies at $10^{\circ}C$ for 10 daysshowed that fruiting bodies harvested after soaking in the solution with $2.5{\times}10^{-2}$ dilution level showed the bestfreshness by general test and color changes. In addition, shear force value of L. edodes fruiting bodies measuredby using texture analyzer showed that $2.5{\times}10^{-2}$ dilution level was the best concentration for keeping flesh texture.

• Food Science and Preservation
• /
• v.21 no.5
• /
• pp.627-635
• /
• 2014

We investigated the changes in the quality characteristics of Doenjang with low salt contents (6, 8, 10, and 12%) and 10% garlic. The Doenjang was analyzed at an interval of a week during its fermentation for six weeks, at room temperature. Its L color gradually decreased, but its a and b colors did not change significantly. Its salinity increased by about 1% after six weeks. In contrast, immediately after its preparation, its pH was gradually decreased and its acidity was increased for the fermentation. The reducing sugar was significantly increased from 1.34~1.88 g/100 g immediately after its preparation to 7.25~9.13 g/100 g after six weeks, which was higher as the salt concentration decreased. The amino-type nitrogen doubled from 100~130 mg% at 0 week to 210~290 mg% at six weeks, which were lower with the higher salt concentrations. The growth curve of the Bacillus fermentation strains of Doenjang increased to two weeks but gradually decreased since, and the growth of the Bacillus was favorable for up to two weeks in the Doenjang with 10% and 12% salt added. Otherwise, the yeast was reduced rapidly during the early fermentation of the Doenjang, and slightly changed after three weeks of fermentation. The results of this study showed that the reducing sugar and amino-type nitrogen contents of the low-salt garlic Doenjang were higher with the lower salt dose, and the physicochemical quality of the 6%-salt Doenjang was not significantly affected. Thus, we suggest that low-salt Doenjang can be manufactured with the addition of 6% salt and 10% garlic.