• Food Science and Preservation
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• v.20 no.3
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• pp.365-371
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• 2013

The organic acids, fuel oil contents and antioxidant activities of Yakju with the addition of rice varieties were investigated. The rice cultivars that were used in this study were Ilmi rice, Hopyung rice, Hopum rice, Hanarum rice, Anda rice and Indica rice. The study results are as follows: the pH values of Ilmi Yakju and Hanarum Yakju were 4.14 and 4.07, respectively, and those of the other Yakjus, 3.92~3.98. The total titratable acid content of the Yakju for which Indica rice was imported from Thailand was highest among the samples. The reducing sugars content of the Yakju for which Indica rice was used was higher than that of the other samples. The ethanol content of the Hanarum Yakju was higher than that of the other Yakjus, and the lowest ethanol content was found for the Indica Yakju. The major organic acid component of the Yakju was lactic acid. The total organic acid content was highest in the Indica rice Yakju. The amounts of the following main fusel oils were highest, in the following order: 2-butyl alcohol, 2-pentanol, N-propyl alcohol, acetaldehyde, ethyl acetate, methyl alcohol and 2-methyl-1-propyl alcohol. The DPPH free radical scavenging activity of the Indica rice Yakju was much higher than that of the Ilmi rice Yakju and the Hanarum rice Yakju. Also, the SOD activity of the Indica rice Yakju was strongest among all the samples. The total polyphenol content of the Indica rice Yakju was the highest among all the samples.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1583-1591
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• 2015

The present study was conducted to determine the effect of lipid sources with different fatty acid profiles on nutrient digestion and ruminal fermentation. Ten rumen and duodenal fistulated Nellore steers (268 body weight${\pm}27kg$) were distributed in a duplicated $5{\times}5$ Latin square. Dietary treatments were as follows: without fat (WF), palm oil (PO), linseed oil (LO), protected fat (PF; Lactoplus), and whole soybeans (WS). The roughage feed was corn silage (600 g/kg on a dry matter [DM] basis) plus concentrate (400 g/kg on a DM basis). The higher intake of DM and organic matter (OM) (p<0.001) was found in animals on the diet with PF and WF (around 4.38 and 4.20 kg/d, respectively). Treatments with PO and LO decreased by around 10% the total digestibility of DM and OM (p<0.05). The addition of LO decreased by around 22.3% the neutral detergent fiber digestibility (p = 0.047) compared with other diets. The higher microbial protein synthesis was found in animals on the diet with LO and WS (33 g N/kg OM apparently digested in the rumen; p = 0.040). The highest C18:0 and linolenic acid intakes occurred in animals fed LO (p<0.001), and the highest intake of oleic (p = 0.002) and C16 acids (p = 0.022) occurred with the diets with LO and PF. Diet with PF decreased biohydrogenation extent (p = 0.05) of C18:1 n9,c, C18:2 n6,c, and total unsaturated fatty acids (UFA; around 20%, 7%, and 13%, respectively). The diet with PF and WF increased the concentration of $NH_3-N$ (p<0.001); however, the diet did not change volatile fatty acids (p>0.05), such as the molar percentage of acetate, propionate, butyrate and the acetate:propionate ratio. Treatments PO, LO and with WS decreased by around 50% the concentration of protozoa (p<0.001). Diets with some type of protection (PF and WS) decreased the effects of lipid on ruminal fermentation and presented similar outflow of benefit UFA as LO.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1880-1893
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• 2015

In this study, Pseudomonas R0-14, which was isolated from Arctic soil samples, showed a clear halo when grown on M9 medium agarose plates containing olive oil-rhodamine B as substrate, suggesting that it expressed putative lipase(s). A putative lipase gene, lipR, was cloned from R0-14 by genome walking and Touchdown PCR. lipR encodes a 562-amino-acid polypeptide showing a typical α/β hydrolase structure with a catalytic triad consisting of Ser₁₅₃-Asp₂₀₂-His₂₆₀ and one α-helical lid (residues 103-113). A phylogenetic analysis revealed that LipR belongs to the lipase subfamily I.3. LipR was successfully expressed in Escherichia coli, purified, and biochemically characterized. Recombinant LipR exhibited its maximum activity towards p-nitrophenyl butyrate at pH 8.5 and 60℃ with a K_m of 0.37 mM and a k_cat of 6.42 s^-1. It retained over 90% of its original activity after incubation at 50℃ for 12 h. In addition, LipR was activated by Ca²⁺, Mg²⁺, Ba²⁺, and Sr²⁺, while strongly inhibited by Cu²⁺, Zn²⁺, Mn²⁺, and ethylenediaminetetraacetic acid. Moreover, it showed a certain tolerance to organic solvents, including acetonitrile, isopropanol, acetone, methanol, and tert-butanol. When algal oil was hydrolyzed by LipR for 24 h, there was an enrichment of n-3 long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (1.22%, 1.65-fold), docosapentaenoic acid (21.24%, 2.04-fold), and docosahexaenoic acid (36.98%, 1.33-fold), and even a certain amount of diacylglycerols was also produced. As a result, LipR has great prospect in industrial applications, especially in food and/or cosmetics applications.

• Journal of dental hygiene science
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• v.7 no.1
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• pp.21-24
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• 2007

Dental caries is initiated by the acid accumulated in dental plaque. Streptococcus mutans, one of a major causal agents of dental caries, is component of the dental plaque and produces various organic acids such as lactic acid as the end-product of glycolysis. As a consequence, we investigated the acid stress response of S. mutans KCTC 3065 in this study. The addition of lactic acid to the growth media had a concentration-dependent effect on the growth of S. mutans. S. mutans exhibited higher maximum culture OD compared with the more acidic growth pH values. At treatment of centration of 20 mmol/L lactic acid in the mid-log phage, cell growth was reduced to 40% relative to the control. The following results were obtained with the treatment of cells with a concentration of 20 mmol/L lactic acid in the mid-log phage for 2hrs: Analysis of fatty acids extracted from cells showed that growth at a concentration of 20 mmol/L lactic acid resulted in changes in $C_{14:0}$, $C_{16:0}$, $C_{18:0}$ and $C_{18:1}$ fatty acids. Protein profiles investigated by SDS-PAGE showed that approximately 70, 60, 45, 40 and 23 kDa proteins were highly expressed in S. mutans KCTC 3065.

• Food Science and Preservation
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• v.23 no.1
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• pp.117-126
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• 2016

This study was performed to provide information for improving the quality characteristics of tangerine peel Soksungjang. Tangerine peel Soksungjangs were prepared with 10% tangerine peel powder by addition of different koji such as Rhizopus oligosporus (RS, RTS) and Aspergillus oryzae (AS, ATS). As a result, the moisture content was not changed and crude protein content decreased during fermentation in all samples. The pH of RS (Soksungjang manufactured with Rhizopus oligosporus koji) and RTS (Soksungjang manufactured with Rhizopus oligosporus koji and 10% tangerine peel powder) was not changed, whereas pH of AS (Soksungjang manufactured with Aspergillus oryzae) and ATS (Soksungjang manufactured with Aspergillus oryzae koji and 10% tangerine peel powder) decreased rapidly after 10 days of fermentation. The acidity values of all the samples increased during fermentation. The major free sugars were glucose, fructose, and maltose; while, the major organic acids were citric acid, succinic acid, acetic acid, and lactic acid in all the samples. The amino nitrogen content and protease activity were highest in the AS and ATS. Conversely, the reducing sugar content and ${\alpha}$-amylase activity were highest in the RS and RTS. The major free amino acids in all samples were glutamic acid, lysine, leucine, and arginine. Sixty kinds of volatile flavor compounds were identified from all samples; the majority of which were 21 alcohols, 14 hydrocarbons, 5 esters, and others identifies as acids, ketones, and aldehydes.

• Korean journal of food and cookery science
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• v.7 no.2
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• pp.81-88
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• 1991

The changes of the contents of chemical components and sensory evaluation of kimchi which were prepared by addition of different amount of ginseng were investigated during fermentation 50 days at $4^{\circ}C$. The data analysis revealed followings; 1. While saltiness was maintained at around 2.3% level during the entire fermentation periods. Kimchi containing 2% and 4% ginseng showed higher pH, reducing sugar, hardness by Instron and lower acidity than kimchi without ginseng. 2. Results from analysis of organic acids contains by HPLC revealed that all three groups contained relatively high concentration of oxalic acid, lactic acid and malic acid. 3. A result of sensory evaluation revealed that kimchi containing 2% and 4% ginseng was higher in hardness, savory taste and carbonated taste, and lower in sour taste, moldy off flavor than kimchi without ginseng, thus scoring high in overall eating quality. Considering all results obtained throughout this experiments, it can be concluded that the addition of small amount of ginseng to kimchi improve overall acceptability and retard rancidity thus increasing the period during which kimchi is eatable.

• Preventive Nutrition and Food Science
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• v.20 no.4
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• pp.292-297
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• 2015

The objective of this study was to compare the effects of adding lactic acid and pectinase, and chaptalization for the quality of apple wine and the production of hazardous compounds (methanol and acetaldehyde). The pH of all of the samples was below 4; therefore, mash seemed to be fermented without any issue. Total acidity was the highest in sample A due to lactic acid addition. Pre-treated groups (samples B, C, and D) showed higher total acidities than that of the control (P<0.05). Pre-treatments might influence the production of organic acids in apple wines. The control and pectinase added sample (sample B) had the lowest alcohol contents. Adding lactic acid produced more alcohol, and chaptalized samples produced more alcohol due to the addition of sugar. Adding pectinase with and without chaptalization was not effective for producing more alcohol. The control sample had significantly higher acetaldehyde content (2.39 mg/L) than the other samples (1.00~2.07 mg/L); therefore, pre-treatments for apple wine fermentation produced a lower amount of acetaldehyde. Among the pre-treated samples, samples C and D showed the lowest acetaldehyde content of 1.00 mg/L and 1.16 mg/L, respectively. On the other hand, a significantly higher amount of methanol was generated for sample A (1.03 mg/L) and sample D (1.22 mg/L) than that of the control (0.82 mg/L) (P<0.05). Adding lactic acid or chaptalization was effective in reducing methanol and acetaldehyde in apple wines.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.491-505
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• 2020

A newly isolated strain, Proteus vulgaris OR34, from olive mill waste was found to secrete an alkaline extracellular lipase at 11 U·ml-1 when cultivated on an optimized liquid medium. This lipase was purified 94.64-fold with a total yield of 9.11% and its maximal specific activity was shown to be 3232.58 and 1777.92 U·mg-1 when evaluated using the pH-stat technique at 55℃ and pH 9 and Tributyrin TC4 or olive oil as the substrate. The molecular mass of the pure OR34 lipase was estimated to be around 31 kDa, as revealed by SDS-PAGE and its substrate specificity was investigated using a variety of triglycerides. This assay revealed that OR34 lipase preferred short and medium chain fatty acids. In addition, this lipase was stable in the presence of high concentrations of bile salt (NaDC) and calcium ions appear not to be necessary for its activity. This lipase was inhibited by THL (Orlistat) which confirmed its identity as a serine enzyme. In addition, the immobilization of OR34 lipase by adsorption onto calcium carbonate increased its stability at higher temperatures and within a larger pH range. The immobilized lipase exhibited a high tolerance to organic solvents and retained 60% of its activity after 10 months of storage at 4℃. Finally, the OR34 lipase was applied in biodiesel synthesis via oleic acid mediated esterification of methanol when using hexane as solvent. The best conversion yield (67%) was obtained at 12 h and 40℃ using the immobilized enzyme and this enzyme could be reused for six cycles with the same efficiency.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.550-563
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• 2000

This study was carried out in order to elucidate the fundamental data on the taste compounds between wild and cultured fishes produced on Chungmu and Wando at the southern coast areas of Korea. For this purpose, the food components of cultured fishes such as red sea bream Pagnus major, Sebastes pachycephalus and flounder, Paralichthys olivaceus being spot lighted for the main sea fish, the staple food and high economic fish were investigated and compared with those of the wild ones. There was a little appreciable difference in the proximate compositions of all the species from localities between wild and cultured fishes. But according to the growing conditions, wild fishes were higher in moisture contents and lower in crude lipid content than those of cultured fishes and little difference was seen in protein and ash contents between the two. With regard to the nucleotides and their related compounds, i.e. ADP, IMP and inosine were detected but ATP and hypoxanathine were not from them. On the other hand, there were little difference in the total taste compounds of all the species from localities and the growing conditions between wild and cultured fishes. But all the species were higher in IMP content. The total of seventeen amino acids were detected in samples. The highly contents of glutamic acid, lysine, aspartic acid, proline, leucine, alanine, valine and alginine were showed and less low contents of cystein, histidine, methionine, tyrosine and phenylalanine were detected. The total amino acids of the others were much alike in that composition. Little difference was seen from localities and the growing conditions between wild and cultured ones. The free amino acids were much alike in that composition of all the species. There was little difference in the free amino acid compositions all the species from localities and the growing conditions between wild and cultured fishes. But taurine was dominant, showing from 39% to 65% of the free amino acid content and it is followed by hydroxyproline, lysine, alanine and glycine in other. There were differences in the organic acid compositions of all the species from localities and the growing conditions between wild and cultured fishes. In addition, cultured fishes were more abundant in the total organic acid compositions than those of wild ones.

• Food Science and Preservation
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• v.14 no.1
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• pp.47-53
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• 2007

Soybean curd was mixed with onion powder to develop new foods, and changes in quality characteristics were investigated. The moisture content of onion soybean curd rose as the proportion of onion powder increased Whiteness (as measured by the L value) was high in soybean cud admixed with 0.1% (w/v) onion powder, Redness (the a value) was not significantly altered (the readings were 1.03-1.54) on addition of various onion powder concentrations. Yellowness (the b value) was similarly unaffected (readings 13.00-13.93) when various levels of onion powderwere added. Free sugar analysis showed that glucose was high in soybean curd (67.22 g/100 g) admixed with 0.1% (w/v) onion powder, The main organic acid was tartaric acid, and control organic acids included citric and oxalic acids at high levels. The major free amino acids were L-arginine, ${\gamma}-Amino-n-butyric$ acid, L-histidine, L-glutamic acid, L-serine, L-tyrosine and L-threonine, and amino acid content were high in soybean curd admixed with 0.2% (w/v) onion powder. Major phenolic compounds of onion soybean curd were quercitrin, protocatechuic acid and caffeic acid. The hardness of onion soybean curd was similar to that of the control when onion powder was added to 0.1% or 0.2% (w/v), and decreasedmore onion powder was added. Organoleptic qualities dropped as onion powder levels increased. In summary, onion powder addition to soybean curd is optimal at the 0.2% (w/v) level..