• Applied Biological Chemistry
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• v.29 no.2
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• pp.212-218
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• 1986

Proteins in Korean rapeseeds, as in many other plantseeds, are usually bound to phytate molecules. These phytate-bound proteins are of little value as foodstuffs because of their poor solubility in digestive systems. Therefore it is necessary to remove phytates from proteins in order to convert these proteins io a useful foodstuff. In the work, an efficient procedure for removal of phytates from defatted Korean rapeseed was found. The influence of pH on the solubility of protein and phytate of rapeseed flour showed that the former was the lowest at pH 5.0 and began to increase as pH further raised. Meanwhile, the latter was the highest at pH 6.0, however, it was decreased abruptly at alkaline pH, especially to content of 1.3% at pH 11.5. The solubility cf protein was relatively high in NaCl aqueous solution at $pH\;6.0{\sim}8.0$, and did not male any noticeable difference depending on NaCl concentration. On the other hand, the solubility of phytate was high at pH of below 6.0 showing an abrupt decrease at pH of above 6.0. The solubility of protein in $CaCl_2$ aqueous solution was highest at $pH\;6.0{\sim}8.0$, however, there was no significant change at the whole range of tested pH of the solution. A maximum solubility of phytate was shown at $pH\;3.0{\sim}4.0$. And it was decreased abruptly at a higher pH of the above range and also decreased at a lower pH with higher $CaCl_2$ concentration. The solubility of phytate in $Na_2SO_3$ aqueous solution was highest at $pH\;5.0{\sim}8.0$. As the concentration goes up the maximum value of solubility was found to move to higher pHs. Depending on the concentration of $Na_2SO_3$, the decreasing pattern was changed in an alkaline solution. The solubility of phytate in the solution containing low concentration of $Ca^{2+}$ ion was low in all treatments at pH of above 7.0 and showed the maximum value at low pH as $Ca^{2+}$ ion concentration increases. The solubility of protein at pH 11.5 showed the highest value in $1mM\;Ca^{2+}$ ion solution.

• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.114-120
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• 1985

This study was carried out to investigate the storage stability of Yackwa (a Korean fried cake made from wheat flour, honey and 20% oil), with the variation in frying oils (soybean oil of fresh or heat-treated corn oil and rapeseed oil) and storage conditions (temperature, humidity and in dark or under fluorescent light) for 20 weeks period. In $5^{\circ}C$ storage, acid and peroxide values increased slowly, showing the peroxide value of 20 meq/kg after 13 weeks. In $40^{\circ}C$ storage, acid and peroxide values increased remarkably. The product became harder at storage humidity of 25% and softer by moistening at storage humidity of 80%. Acid and peroxide values of Yackwa from corn, rapeseed and soybean oils increased with storage period, to a different extent. The values of fluorescent groups, especially rapeseed oil group, were higher than those of control groups and the heat-treated oil groups were higher than those of fresh oil groups. Sensory scores for rancid flavor were gradually increased with the storage period in all groups. There was no significant difference with the kinds of frying oils, storage conditions and heat treatment. Correlation of sensory scores with acid values was positive throughout whole storage period, with low ${\gamma}-values$. Its correlation with peroxide values was positive up to 6th week but negative at 9th week of storage.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.194-199
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• 2002

Eight Korean wheat cultivars were milled and evaluated for the properties of white layer cake-making, compared to a commercial soft wheat flour. Milling yields of the Korean wheat cultivars ranged from 62.5 to 71.8%. The protein and ash contents of flours milled from Korean wheat cultivars ranged from 7.70 to 10.58% and 0.51 to 0.71%, respectively. Woorimil, Alchanmil and Olgeurumil flours, having low protein content, showed very weak mixing characteristics. Even though Eunpamil and Geurumil flours showed longer mixing time and higher peak height, they had week dough stability. Slight differences in pH and specific gravity of cake batter were observed among the Korean wheat flours. Cake volume measured by rapeseed displacement was in the range of $837.5{\sim}952.5\;cc$. Alchanmil flour demonstrated the highest specific volume of 2.40, and the other domestic flours symmetrical and uniform than those with the commercial soft wheat flour. Volume of white layer cakes was negatively affected by flour protein content and somewhat associated with crumb softness. Crumb color of cakes prepared with domestic wheat flours was slightly darker and more yellowish. Hardness of fresh cakes prepared with domestic flours ranged from 307.33 to 416.60 $g_f$.

• Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.87-96
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• 2023

This study was designed to determine the apparent digestibility coefficients of soybean meal, soy protein concentrate (SPC), soy protein isolate (SPI), rapeseed meal (RSM), pea protein concentrate (PPC), wheat gluten meal (WGM) and wheat flour (WF) for olive flounder, Paralichthys olivaceus. A reference diet (RF) was formulated to meet the nutrient requirements of olive flounder with 1% chromic oxide (Cr₂O₃) as an inert indicator. Test diets were prepared to contain 70% RF and 30% of the test ingredient. Olive flounder, averaging 150 ± 8.0 g, was cultured in 400-L fiberglass tanks at a density of 25 fish per tank. Fecal collection columns were attached to each tank. Fecal samples were obtained from triplicate groups of fish for 4 weeks. Dry matter digestibility of SPC (75%) and WGM (76%) were significantly higher than the other test ingredients. Protein digestibility of SPC (85%), PPC (88%) and WGM (89%) were significantly higher than the other test ingredients, and protein digestibility of RSM (77%) and WF (76%) was lower than the other ingredients tested. Lipid digestibility of SPC (72%) and SPI (69%) were significantly higher than the other test ingredients. Energy digestibility of SPC (85%) and WGM (82%) were significantly higher than that of others tested ingredients. The availability of amino acids in WGM was generally higher than in other plant-feed ingredients. Therefore, SPC and WGM were seems to be efficient as potential protein sources for olive flounder compared to other tested ingredients. Overall, findings of the current study may assist in more efficient and economical formulation of diets using plant feed ingredients for olive flounder.