• Journal of Adhesion and Interface
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• v.20 no.3
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• pp.87-95
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• 2019

In the present study, the effect of alkali treatment of rice straw on the flexural properties and impact strength of rice straw/recycled polyethylene composite was investigated. Alkali treatments were performed by means of two different methods at various sodium hydroxide (NaOH) concentrations. One is static soaking method and the other is dynamic shaking method. The composites were made by compression molding technique using rice straw/recycled polyethylene pellets produced by twin-screw extrusion process. The result strongly depends on the alkali treatment method and concentration. The shaking method done with a low concentration of 1 wt% NaOH exhibits the highest flexural and impact properties whereas the soaking method done with a high concentration of 10 wt% NaOH exhibits the highest properties, being supported qualitatively by the fiber-matrix interfacial bonding of the composites. The properties between the two highest property cases above-described are comparable each other. The study suggests that such a low concentration of 1 wt% NaOH may be used for alkali treatment of natural fibers to improve the flexural and impact properties of resulting composites, rather than using high concentrations of NaOH, 10 wt% or higher. Considering of environmental concerns of alkali treatment, the shaking method is preferable to use.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1398-1403
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• 2009

Present study deals with variations of physicochemicals including $\gamma$-aminobutyric acid (GABA), $\gamma$-oryzanol, free sugar, lipoxygenase activity, fat acidity, and germination rate from Korean brown rice cultivars. With increase of storage time and temperature, GABA, $\gamma$-oryzanol, lipoxygenase activity, and fat acidity increased, whereas free sugar and germination rate was reduced. Among cultivars, 'Gopumbyeo' exhibited the highest contents in GABA and $\gamma$-oryzanol during 12 weeks storage at $25^{\circ}C$ (GABA: $28.6{\pm}5.6{\rightarrow}170.4{\pm}4.6\;mg/100\;g$, $\gamma$-oryzanol: $6.1{\pm}0.7{\rightarrow}6.7{\pm}0.4\;mg/g$) and 'Ilpumbyeo' significantly decreased in free sugar during 12 weeks storage at $10^{\circ}C$ ($1,423.7{\rightarrow}1,058.4\;mg/100\;g$). Moreover, 'Taebongbyeo' exhibited the highest quality owing to low lipoxygenase activity, low fat acidity, and high germination rate. In free sugar compositions, sucrose exhibited the highest content (>70%), followed by fructose (>7%), raffinose (>5%), glucose (>3%), and maltose (>2%) during storage. Based on our results, changes of physicochemicals in stored brown rice may be important information in processing food and functional properties.

• Korean Journal of Food Science and Technology
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• v.9 no.2
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• pp.144-152
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• 1977

The physiochemical properties of eight different cultivars or newly bred lines of glutionous rice were investigated and obtained following results; (1) The gelatinizing temperature, blue value and alkali number of starch separated from the sample cultivars or lines were similar to those of starch from conventional cultivar Olchal. The expansive power of three newly bred lines were somewhat weaker than that of starch from conventional cultivar, but the expansive power of other four lines were similar to that of conventional cultivar. (2) pH of cooked rice of the ten sample cultivars or breeding lines showed no discernible differences rangeing from 6.54 to 6.60. (3) The degree of gelatinization of cooked rice of newly bred lines were rather lower than that of conventional ones, but the degree of their retrogradation were somewhat higher than that of conventional cultivars. (4) In order to improve the palatability of cooked rice of Tongil (common rice), glutinous rice were mixed in different rate. The results showed that a mix ratio of six per cent glutinous rice was most favourable. The acceptability of common Tongil rice was improved when it was cooked with four to six per cent of glutinous rice mixed, and it showed no significant difference from that of Akibare alone cooked rice. Also no difference was noticed among newly bred glutinous lines in the acceptability when they cooked with common Tongil rice mixed. (5) Injolmi, Yaksik, Misitgaru, Twipap and Yugwa were prepared from glutinous rice of sample cultivars and or breeding lines to study their characteristics in processing and their acceptability. The results indicated that the acceptability score of newly bred lines were lower than that of conventional cultivar in cases of Twipap and Yugwa, but in cases of Injolmi, Yaksik and Misitgaru, identical score was obtained from both of newly bred lines and conventional cultivars.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1646-1652
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• 2002

Si-Raw is a raw cured meat (raw, cured meat fermented with steamed rice) produced by the aboriginal people of Taiwan. In order to prevent food poisoning or intoxication from botulism, new methods of monitoring the production base on hurdle technology were investigated. New methods investigated incorporated citric acid, sodium hypophosphite, Monascus anka mash, plum paste or lactic acid bacteria inoculum added separately to meat with steamed rice and salt to lower the Aw (water activity) and pH values of the products to control the microbial growth. Results showed that anaerobic bacterial counts, lactic acid bacterial counts and aerobic bacterial counts for the products of all treatments were less than $10^6$, $10^5$ and $10^2cfu/g$, respectively. Sodium chloride content of all products was above 5.46%, water activity was below 0.939 and pH value was below 4.27. IMP was lower and ATP and hypoxanthine were higher. ATP concentrations were higher in the samples which contained the anka mash. Result of sensory panel test indicated that most people preferred the products with added sodium hypophosphite. Except for the fact that the content of tryptamine in the sample with Monascus anka mash was higher, the amine concentrations for all treatments were lower than those of other fermented meat products. The amino acid nitrogen content was higher in the product made from raw meat treated with citric acid, but lower in the other products. Neither Clostridium botulinum nor Trichinella spiralis were detected in any of the treatments. The result may indicate that hurdle technology is effective for hygiene and safe producing Si-Raw.

• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.400-406
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• 2021

The purpose of this study was to evaluate the microbial contamination level of Korean traditional rice cakes (Garaetteok, Injeolmi, Gyeongdan), as well as manufacturing environment of small-sized businesses in Korea. The contamination levels of total aerobic bacteria, coliforms, and Bacillus cereus in raw materials were 3.76-4.48, 2.21-4.14, and 1.02-1.15 log CFU/g respectively. On the other hand, Escherichia coli was not found. It has been found that the contamination level of total aerobic bacteria, coliforms, and B. cereus in the raw material decreased after the washing process, but it increased again during the soaking and grinding process. However, after the steaming stage, the contamination level increased again during the molding and cooling process, suggesting the need to take cautions in managing cooling water and molded rice cakes in the process. These results suggest that the safe management of cooling water and taking cautions in the drying process after steaming of rice cakes are necessary for controlling cross-contamination. No E. coli was detected during the manufacturing process involving all tested rice cakes. The microbial contamination level of manufacturing environment such as rice grinder and rice cake forming machine was high. Therefore, in terms of food safety strategy, it is necessary to consider introducing systematic cleansing and disinfection procedure to processing equipment and environment for the sake of reducing microbiological risks.

• Research in Plant Disease
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• v.14 no.3
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• pp.143-152
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• 2008

Mixed-planting of two rice cultivars, HP ('Hopyeongbyeo') and NP ('Nampyeongbyeo'), having a dissimilar susceptibility to rice blast was practiced for chemical-free control of rice blast in the field. The HP/NP combination was selected for applying under mechanized agricultural conditions. Because they have similar genetic characteristics such as seed germination and heading time, culm length, rice quality and size of rice grains except susceptibility to blast. Incidence of panicle blast was reduced 50.4 % compare with supposed blast incidence by HP/NP mixed-planting when the seeds of two cultivars were combined 1 to 1 as weight. Supposed blast incidence was estimated from reduction of rice blast caused by addition of a resistant cultivar NP. Race diversity of Magnaporthe oryzae was examined for correlation with control effect of HP/NP mixed-planting on rice blast. The population of dominant race KJ-101 was diminished and replaced with various co-existing races and eleven new races were appeared in mixed-planting plot. Total number of race isolated from mixed-planting plot was not largely different from mono-culture. However, detection frequency of the new race was increased and variation of the population size of each race was decreased in mixed-planting plots. It was shown that a biased community with a dominant race (KJ-101 or KI-181) was altered to a balanced one of coexisting races. From these results, it was supposed that the balanced diversity among co-existing races within a community might be correlated to control effect by HP/NP mixed-planting on rice blast. Further more, it should be studied that genetic characteristics of the individual race including a virulence on cv. HP and NP was examined for verifying a correlation of mixed-planting effect and race diversity.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.570-576
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• 2011

The effect of nuruks and crude amylolytic enzyme on free amino acid and volatile components of brown rice vinegar prepared by static cultures was investigated. Five groups consisted of AV (100% nuruk without crude amylolytic enzyme), BV (75% nuruk; 25% crude amylolytic enzyme), CV (50% nuruk; 50% crude amylolytic enzyme), DV (25% nuruk; 75% crude amylolytic enzyme) and EV (100% crude amylolytic enzyme without nuruk). Free amino acid content in AV vinegar (132.06 mg%) was lower than the others (184.56-191.22 mg%). Acetic acid, 3-methyl butyl acetate, acetoin and isoamyl alcohol were major volatile components as analyzed using gas chromatography-mass spectrometry after headspace solid-phase microextraction. Acetic acid in AV and EV samples represented 67.56% and 55.53% of total GC peak area, respectively. E-nose provided different patterns in each case showing variation in sensory properties.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.171-178
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• 2022

In this study, the quality characteristics of rice cookies supplemented with different types of insect powder (Tenebrio molitor, Protaetia brevitarsis, and Gryllus bimaculatus) were assessed according to the quantity of insect powder used (0, 1, 2.5, 5, and 7.5 g). No significant differences were observed in rice cookie densities or water content. The pH value and spread factor decreased with increasing insect powder content (p<0.05); however, a significant increase was observed in the loss rate (p<0.05). Crude ash, crude fat, and crude protein content significantly increased with higher concentrations of insect powder (p<0.05). Moreover, lightness and yellowness decreased, whereas redness increased with higher insect powder concentrations (p<0.05). Hardness significantly decreased, whereas the antioxidant capacities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals increased with higher insect powder concentrations (p<0.05). Finally, insect powder can prove a valuable resource in rice cookie production, considering its nutritional value, consumer preference, and antioxidant properties.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.1
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• pp.39-48
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• 2021

In this study, characteristics of solid-state fermentation distilled spirits with nuruk (fermentation starter) and sorghum were investigated. The starch digestion activity was highest in black koji (A. usamii) at 359.15 U/g dry base, white koji (A. luchuensis) at 306.98 and yellow koji (A. oryzae) at 15.31 was followed. The pH of the solid-state fermented mash in yellow, white and black koji showed 5.09, 4.46 and 4.50 respectively with significant differences (p<0.001). The total acid content of white and black koji was 0.73% as citric acid. The alcohol content of mash prepared with yellow, white and black koji was 4.34, 4.24, 3.89% respectively. The contents of reducing sugar showed 3.28, 3.23 and 2.64%. Total sugar were 14.88, 17.84 and 17.60% respectively. The alcohol content of each distillate ranged from 44.3 to 39.9%, and the furfural content in yellow koji was 1.25 times lower than the others.

• Journal of Food Hygiene and Safety
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• v.27 no.2
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• pp.161-168
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• 2012

This study was conducted to evaluate microbial contamination levels of Korea traditional rice cakes such as Sirutteok, Garaetteok and Gyeongdan in the manufacturing process and environment. The microbial contamination levels such as total aerobic bacteria, fungi, coliforms, Escherichia coli, Staphylococcus aureus, Bacillus cereus and Clostridium perfringens of rice cake products were analyzed. The contamination levels of total aerobic bacteria, coliforms, fungi and B. cereus in raw materials were in the range of 2.4~4.5, ND~1.9, 1.2~2.1 and 1.0~2.1 log CFU/g, respectively. The microbial contamination levels of total aerobic bacteria, coliforms, fungi and B. cereus in manufacturing process of rice cakes were increased in the soaking and grinding steps and were decreased in steaming step. E. coli, S. aureus and C. perfringens were not detected in any manufacturing process and environment. The microbial contamination levels of raw materials and final products of rice cake were suitable for microbial safety standard in Korea. However, the manufacturing environment such as equipments and employee's sanitation were in trouble for microbial safety. The results of this study suggest that safety educatio n for personal hygiene and safetymanagement in processing environment are continuously required to assure safety in working environment and employee's individual hygiene.