• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.153-160
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• 1999

Storage stability of boiled and freeze dried loach and antioxidative effect of Zanthoxylum schinifolium were studied to confirm the possibility in development of instant choo o tang(Korean traditional loach soup). Packaging and storage temperature did not cause a measurable change in in vitro protein digestibility and trypsin indigestible substrate within 45 days of storage but remarkable quality changes were occurred in all samples stored after 60 days. Vacuum packaging and low temperature storage(4 oC) had some effect in retarding protein quality deterioration due to delaying polyunsaturated fatty acid oxidation. Maximum peroxide value and TBA value were reached in 15 days, and there were a slow(TBA value) and rapid reduction(POV) after peaks were reached. In contrast, increasing brown pigment development and fluorescence intensity continued until 90 days of storage. Treatment of ethanolic extracts from Zanthoxylum schinifolium prior to freeze drying could protect against lipid oxidation of freeze dried loach products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.438-443
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• 1999

A livetin solution(LS) containing yolk immunoglobulins(IgY) was separated by treating the egg yolk with natural gum, carrageenan. Carrageenan has been used as a food ingredient. Relative absorbance of IgY LS after proteolysis was investigated. IgY LS was fairly stable to pepsin digestion at pH 3.0. However, IgY LS appeared to be susceptible to pepsin digestion at pH 2.0, showing 18% of relative absorbance and complete breakdown H chain after 30 min exposure. Relative absorbance of IgY LS was considerably high after exposure to trypsin and chymotrypsin for 8 hr. IgY LS showed especially good stability to chymotrypsin digestion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.234-241
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• 1995

Effect of microwave heating on the oxidative stability of the soybean oil, sesame oil, butter and margarine were investigated by mearsuring fatty acids amout and tocopherol losses. The index for chemical properteis, free fatty acid, peroxide value, anisidine value, carbonyl value, conjugated diene and triene levels were also mearsured in the oil samples for 5, 10, 15 and 20 min of heating in a microwave oven. No significant difference was observed on the fatty acids composition in the fats and oils before and after microwave heating. During microwave treatment, the oxidative degradation of the tocopherols in the samples became greater with increasing heating time. The amount of tocopherols in the soild fats, butter and margarine, dropped drastically after 5 min of heating and reduced to 95% of their original levels after 20min heating ${\gamma}$-tocopherol in butter showed the most unstable states and completely destroyed during microwave treatment for 20min. On the other hand, 80% of tocopherols in the liquid oils were still remained after 5min of heating except $\delta$-tocopherol in sesame oil.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1289-1293
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• 2008

Fresh egg yolk (EY) was enzymatically modified using phospholipase $A_2$ ($PLA_2$) to produce an enzymatically modified-egg yolk powder (EM-EYP). The EM-EYP offered significantly higher emulsifying activity, emulsion stability, protein solubility, and mayonnaise stability than the control EYP. By employing $PLA_2$ in the enzymatic modification process, structural changes occurred in the phospholipids and lipoproteins of the yolk, and cleavage of apo-high density lipoprotein (HDL) components (Mw 105 kDa) was detected by sodium dodecyl sulfate-polyaerylamide gel electrophoresis (SDS-PAGE). Based on its functional properties, EM-EYP has great potential as a replacement for fresh EY in the production of processed food products such as mayonnaise.

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.318-322
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• 1994

Aluminium alloy, comprising water, silicone manganese and porous aluminium carrier added into soybean oil in order to investigated its effect on polar lipid content, polymer content, conjugated dienoic acid and free fatty acid value during deep-fat frying at 185$^{\circ}C$. Increase rates of polar lipid and polymer content of the frying ell were reduced about one thirds of the oil without aluminium alloy during deep-fat frying. The aluminium alloy, however, have no significantly effect to inhibit the increase of conjugated dienoic acid and free fatty acid value. Treatment of the frying oil with aluminium alloy was found to be able to inhibit polymer and polar lipid formation.

• Preventive Nutrition and Food Science
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• v.4 no.3
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• pp.175-179
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• 1999

To develop a production method for modified starches with less pollution, pH adjustment and gamma irradiation were applied to commerical corn starch. Blue values were significantly decreased , while alkali number, optical transmittance and solubility markedly increased when gamma irradiation was applied to pH 2 adjusted corn starch. Water binding capacity and swelling power at pH 5 were the highest among the samples. Gelatinization viscosity was considerably affected by gamma irradiation and pH of the starch. Gamma irradiation of pH 2 adjusted starch showed the lowest peak viscosity and the best cooling stability among the tested samples . Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability seems feasible by controlling the pH of the starch and gamma irrdiation.

• The Korean Journal of Food And Nutrition
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• v.9 no.3
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• pp.325-330
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• 1996

Foaming capacity (FC) and stability (FS) of protein recovered from red crab (Chitinonecetes opilio) processing in water and soybean protein isolate were determined at pH 2.0~10.0 in water and NaCl solution. The FC values for both proteins showed the lowest values at the isoelectric point (pH 4.0) and increased nth an increase in pH above the isoelectric point. FC of RCP was higher than that of SPI at pH 10.0 in water and both NaCl solutions. FC of SPI increased with an increase in NaCl concentration at pH 4.0 and 6.0, but FC of RCP was not affected. The highest FS values for both proteins were obtained at pH 4.0 in water. At pH 2.0, FC of RCP decreased with NaCl concentration increase, but FS increased. NaCl concentration had little effect on FS of RCP at pH 4.0 and 6.0, but the FS decreased at pH 10.0. FS of SPI was similar to that of RCP at pH 2.0 and increased with NaCl concentration Increase from 0.1 to 0.5M NaCl at pH 10.0.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.364-367
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• 2001

We gamma-irradiated to natural casings from lamb and pork to improve sanitary quality and microbiological shelf stability of sausage stuffed in animal intestine-induced natural casing from lamb and pork. The microbial changes of irradiated casings and the microbial growth of the sausages with gamma-irradiated natural casings were observed. Population of total aerobic bacteria was decreased by gamma irradiation, dependent upon the irradiation dose. The number of microflora in lamb and pork casings was reduced by about 5.5 log cycle at 5 kGy. Population of total aerobic bacteria of sausages stuffed in non-irradiated lamb and pork casing was about 3.6 log CFU/g after just manufacture and was about 7 log after 10 day storage. However, population of total aerobic bacteria of sausages with 3 kGy-irradiated and 5 kGy-irradiated casings was 2.48 and 0.32 log in lamb, and 2.78 and 0.60 log in pork, respectively. Gamma irradiation to animal intestine- induced natural casings was effective and thus, can be used for enhancing shelf life of final products due to reduction of the number of contaminated microflora.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.960-964
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• 2003

Effects of pH, sugars, organic acids, and metal ions on the stability of anthocyanin pigments extracted from mulberry (Morus alba L) fruit were studied. The pH had marked influences on the color of the anthocyanine pigment: i.e. the lower pH of the anthocyanin solution was, the more stable and intense of the pigment was. Among the sugars, sucrose was the most deleterious followed by fructose, glucose and maltose. Among the organic acids, maleic acid was found to be the most effective in stabilizing the pigment followed by acetic acid, citric acid and tartaric acid. Most metal ions except C $u^{+2}$ and F $e^{+3}$ were found to be effective in stabilizing the pigment.

• The Korean Journal of Food And Nutrition
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• v.11 no.2
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• pp.159-164
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• 1998

pH stability of sweet potato $\beta$-amylase modified with IO4-oxidized soluble starch was increased at pH 3, 5~9 and 11. And optimum pH was 3 and 5 for modification. Thermal stability of the enzyme modified with IO4-oxidized soluble starch was increased at 6$0^{\circ}C$ for 15 min. pH stability of barley $\beta$-amylase modified with IO4-oxidized soluble starch was increased at 3~4 and 8~11, and more increased at pH 3 and 8~11 in the presence of $\alpha$-cyclodextrin.