• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.627-632
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• 2019

In this study, Laminaria japonica was used as a substrate for a mixed aerobic microbial consortium. Laminaria japonica is well-known as a representative brown algal biomass possessing advantages of cheap cost, and high productivity and carbohydrate content. A biological saccharification system was established by inoculating and enriching the mixed aerobic microbial consortium. Production of the soluble carbohydrate and reducing sugar at different hydraulic retention times (HRT) was observed. The efficiency of saccharification increased according to the decrease of HRT. The maximum saccharification yield in a continuous biological pretreatment process was 17.96 and 4.30 g/L/day for the soluble carbohydrate and reducing sugar, respectively at the HRT of 1 day. In contrast, the staccharification yield decreased drastically at the HRT of 0.5 day. Experimental results indicate that Laminaria japonica is a promising material for the production of useful products, in particular for the saccharification through a biorefinery process. It can thus be concluded that a continuous biological pretreatment process using a mixed cultivation system can be successfully employed for the biorefinery technology.

• Food Science and Preservation
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• v.25 no.1
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• pp.62-70
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• 2018

This study investigates, the physicochemical characteristics of Sengmaksan (SM) prepared with Liriope platyphylla (LP) that had been roasted for different times (0, 30, 60, and 90 min, denoted as S-0, S-30, S-60, and S-90, respectively) The Hunter's color values such as lightness (L), redness (a), and yellowness (b) were the highest in S-0, while the lowest was found in S-90. The amount of soluble solid and reducing sugar content of S-60 were higher than the others. None of the samples exhibit significant differences in, their pH and acidity. The total content of phenolic compounds increased with the LP roasting time, but the total flavonoid and total anthocyanin contents of the SM decreased at the same time. The total ginsenoside (Ro, Rb2, Re, Rf, Rg1, Rg2, Rg3, Rh1, and Rh2) content did not show significant differences. The DPPH and ABTS radical scavenging activities increased according to the concentration, as well as with the LP roasting time. The ferric reducing antioxidant power (FRAP) showed trends similar to the radical scavenging activity, but it was more sensitive to the LP roasting time. From these results, the active ingredient in S-60 was higher, and the antioxidant activities of SM increased along with the roasting time of LP.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.704-708
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• 1994

This study was performed to compare quality of citron juice as affected by the extraction method. The yield of citron juice was 24.49% by method I (rotary-crushing and screening), 18.09% by method II (pressing) and 12.60% by method III (belt-pressing), respectively. Juices by methods I and II had more soluble solid contents and essential oil and pulp volume than that by method III. Method III was higher in titratable acidity than methods I and II. The contents of fructose, glucose and sucrose in method III were 0.54%, 0.37% and 1.11%, respectively, which were lower values than those in other methods. But there was no siginificant difference in the contents of total sugar by the extraction method. For fatty acids composition, the contents of oleic acid in method I, palmitic acid, linoleic acid and linolenic acid in method II, and stearic acid in method III, respectively, were highest when compared with other methods. The contents of free amino acids detected in method III were smaller than those in methods I and II. Threonin was detected only in method I, methionine and cystine were not detected in methods I. II and III. But the contents of the total amino acids in method III were $1.3{\sim}1.6$ times as large as those in methods I and II.

• Culinary science and hospitality research
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• v.20 no.6
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• pp.136-146
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• 2014

This study aimed to determine the physiochemical changes during maturation to examine the preparation of watery Kimchi with wild vegetables from Gangwon Province, and its use. The wild vegetables in this study included Ligularia fischeri, Aster scaber Thunb, and Cirsium setidens; a comparison was made between preservation in a saline solution and pre-treatment with blanching. As for treatment before preparation of watery Kimchi, the water content was the lowest at 81.45% for Aster scaber Thunb preserved in a saline solution and was found to be 87.39% for blanched Cirsium setidens. Blanching resulted in higher L, b, and a values for color value than treatment with a saline solution and Ligularia fischeri got the highest hardness, followed by Aster scaber Thunb and Cirsium setidens, from both types of treatment. As for the physiochemical properties during maturation, the total soluble solid content and salinity were kept higher by treatment with a saline solution than by blanching, whereas pH tended to get lower in both types of treatment. Turbidity became higher one week after treatment with a saline solution, but varied insignificantly afterward by any type of treatment. As for free sugar, both types of treatment increased the content of glucose and fructose and kept that of sucrose and maltose constant during maturation. As for overall acceptability, blanched watery Kimchi made of Cirsium setidens got the highest preference.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.5
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• pp.603-608
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• 2007

Changes in physicochemical quality and antioxidant activity of kiwifruits by the low dose electron beam irradiated(0, 0.3, 0.6 kGy) were investigated. Fruits were stored at $20^{\circ}C$ for 28 days and evaluated after 0, 1, 2, 3, and 4 week storage. Irradiation did not affect 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities, and pH. Vitamin C contents of irradiated fruits were higher than non-irradiated fruits. Irradiation caused no significant change in total sugar contents and reducing sugar contents. Soluble solid contents in irradiated fruits were higher than non-irradiated fruits for the initial storage period but showed lower increment rate during the storage period. Organic acid contents of irradiated fruit did not show significant effect for the initial and during the storage periods, rate of decline in organic acid content of irradiated fruit were not significantly changed. Results indicated that electron beam irradiation of kiwifruit up to 0.6 kGy is effective in was delayed ripening with no significant changes on antioxidant activity and physicochemical qualify of kiwifruit.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.128-138
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• 1985

This study was conducted to elucidate the shelf-life and quality changes in relation to biochemical components in leaf lettuce (Lactuca sativa L.). The shelf-life of leaf lettuce at room temperature was 2 to 3 days. But it was extended to 3 weeks by packaging in a 0.01 mm thick polyethylene film sack when stored at $3^{\circ}C$. The ascorbic acid contents of fresh leaf lettuce was 25 mg per 100 gram fresh weight. The acid at room temperature was almost destroyed after 4 days storage. But the contents of ascorbic acid at $3^{\circ}C$ maintained about 50 to 60% of the initial level in packaging of polyethylene film sack after 8 days storage. The content of chlorophyll was greatly decreased at room temperature but no significant changes were found at $3^{\circ}C$. The changes of total sugar and reducing sugar contents during storage were not very different between treatments. The contents of alkali soluble protein and free amino acid gradually increased in the treatments of polyethylene film sack packaging during storage in general, but the contents decreased after the increase in control treatment. Nucleic acid content, peroxidase and polyphenoloxidase activities were measured and discussed in relation to the leaf senescence.

• Food Science and Preservation
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• v.24 no.8
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• pp.1088-1093
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• 2017

This study was conducted to investigate the effects of drying methods for Citrus junos peels on quality characteristics of the hot-water leachate from teabags containing those peels. Fresh peels were hot-air ($50^{\circ}C$), cold-air ($30^{\circ}C$), or freeze-dried ($-45^{\circ}C$), powdered to a size of 40 mesh, packaged with a paper sachet, and then the packaged teabags were leached for 10 min with hot-water ($70^{\circ}C$). $L^*$ value (lightness) and $-a^*$ value (greenness) of the peel powder were the highest in the freeze-dried samples. Soluble solids and titratable acidity of the teabag leachate were in the following order; cold-air, freeze, and hot-air dried samples. Among free sugar contents in all samples, fructose content was the highest, followed by glucose and sucrose. Fructose and glucose contents were not affected by drying methods. There was no significant difference in the flavonoid content among the peels dried using three drying methods. DPPH radical-scavenging activity of the leachate was the highest in the cold-air dried sample. These results suggest that cold-air drying would be an effective method to enhance the quality of hot-water leachate of teabags prepared from C. junos peels.

• Food Science and Preservation
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• v.10 no.3
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• pp.302-307
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• 2003

In the present study, we investigated the quality characteristic of old pumpkin extract treated with enzymes. As a results, all the groups treated with pectinase were better in quality characteristic than control group and the group treated with 0.15％(w/w) pectinase was specially great. All the groups treated with simultaneous pectinase and cellulase were higher in the extraction rate than the groups treated with pectinase or cellulase. The experimental groups were divided into non-treated control(I) and three treatment groups(II- IV) for optimum condition of enzyme treatment. The II and IV groups were treated with 0.15％(w/w) pectinase and 0.15％(w/w) cellulase, respectively, and the ill group was treated with both 0.15％(w/w) petinase and 0.05％(w/w) cellulase. Yield for old pumpkin extract of the III group (86.94％) was higher than that of other groups, but there were no significant difference among the groups in soluble solide content and pH of the extract. Reducing sugar and total sugar contents in the ill group were 2.81％ and 4.60％, respectively. Total carotene content in the II group (5.36 mg％) was higher than other groups. Old pumpkin extracts in all the groups showed nitrite-scavenging ability to pH 1.2, 3.0 and 4.0. Total free amino acid content in the III group (176.7 mg％) was higher than other groups. Citrulline contents in the II and III groups were detected 1.66 and 1.41 mg％, respectively but the contents in other groups were not detected.

• Food Science and Preservation
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• v.30 no.6
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• pp.983-990
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• 2023

This study was conducted to develop a preservation technology that can induce changes in physicochemical properties to effectively utilize of persimmon leaves. The application effects of steaming or freezing technique were investigated. Astringent persimmon leaves were steam-blanched (100℃, 30 sec) or frozen (-20℃, 15 d), followed by hot-air drying (50℃). The physicochemical properties of the extract obtained by hot-water leaching from the dried leaves were compared. The extract of leaves dried without pretreatment was used as a control. L* value was higher in steamed than in control and frozen. a* value was highest in the control. The browning index was higher in the frozen and lower in the steamed than in the control. Soluble solids were the highest in the steamed and the lowest in the frozen. Sucrose content was relatively high in the steamed, and the glucose and fructose contents were relatively high in the frozen. Total polyphenol content and DPPH radical scavenging activity were higher in steamed and lower in frozen than in control. Thus, it was confirmed that steam or freeze pretreatment after harvesting persimmon leaves affects the extraction yield, color, antioxidant capacity and component changes of dried persimmon leaves. Unlike steaming, freezing pretreatment showed the effect of promoting decomposition and browning reactions, and it is considered useful when such an effect is needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.4
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• pp.501-505
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• 2003

In order to use as a new functional food material, chemical components of propolis and its extracts were surveyed. The contents of crude fat, nitrogen free extract, crude protein, ash and crude fiber in propolis were 86.41%, 7.32%, 2.71%, 1.05% and 0.20%, respectively. The mineral contents were in the order of Na (120.40 mg%), Ca (115.40 mg%), K (105.87 mg%) and Ca were higher in water extract than alcohol extract. Free sugars were composed of sucrose 152 mg%, glucose 114 mg% and fructose 6 mg%. The major amino acids of propolis were lysine 395.29 mg%, cystine 267.66 mg% and glutamic acid 248.14 mg%, respectively. Eight fatty acids in propolis were identified and the major fatty acids were oleic acid (51.89%), myristic acid (20.86%) and palmitic acid (20.28%). Myricetin, quercetin, apigenin and kaempferol were shown as major flavonols and total flavonol contents were higher in 50% ethanol extract than any other extracts. Major Polyphenol compounds in four kinds of extracts were gallic acid, chlorogenic acid, catechin, epigallocatechin gallate, epicatechin and epicatechin gallate.