• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.532-537
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• 1991

Effect of storage temperature fluctuation on quality of frozen breaded raw shrimp was studied. Storage experiments were undertaken as follows; First, after storage at $-20^{\circ}C$ for 20 days or 40 days, storage temperature of materials were raised to $-15^{\circ}C\;or\;15^{\circ}C$, and then stored at these temperatures, And second, by repeating for 5, 10 and 15 times by 3 conditions ($-20{\rightarrow}-15^{\circ}C{\rightarrow}-20^{\circ}C,\;-20{\rightarrow}-10^{\circ}C{\rightarrow}-20^{\circ}C\;-20{\rightarrow}-5^{\circ}C{\rightarrow}-20^{\circ}C$) with temperature fluctuation during storage. Quality changes were measured by determining extractability of salt-soluble protein, volatile basic nitrogen, thiobar-bituric acid, pH and microbiological changes at regular intervals. Rise in storage temperature from $-20^{\circ}C\;to\;-15^{\circ}C$ had not caused significant change on it's quality, but rise up to $-5^{\circ}C$ caused some change in quality without relationship with storage period before temperature rise. Fluctuation of storage temperature from $-20^{\circ}C\;to\;-15^{\circ}C$ of frozen breaded raw shrimp did not cause noticeable changes on it's quality. But temperature fluctuation from $-20^{\circ}C\;to\;-10^{\circ}C\;or\;-5^{\circ}C$ caused remarkable changes of it's quality, according to the increase of fluctuation times and temperatures.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.168-174
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• 2005

This study was carried out to investigate the feeding effect of wild grape wine by-products on pork qualities. The chemical composition, volatile basic nitrogen, thiobarbituric acid reactive substances and pH were not significantly different between control and wild grape pork, but the cholesterol and roast loss of wild grape polk. were lower than those of the control, and 1l1e salt soluble protein extractability of the control was lower than that of the wild grape pork. The Hunter's $a^{\ast}$ and $b^{\ast}$ value of wild grape polk. meat were higher than the control, the $a^{\ast}$ value of wild grape polk. meat was higher than the control, but the $L^{\ast}$ value of meat and fat were not significantly different between control and wild grape pork. The cohesiveness, gumminess and chewiness of control(respectively $66.2\%$ 428kg and 189g) were higher than wild grape polk. (respectively $61.4\%$ 357 kg and 154 g). The total amino acid composition of polk. were not significantly different between control and wild grape wine, The glutamic acid, leucine, arginine and aspartic acid were major amino acids in control and wild grape pork. The arachidonic acid $(C_{20:4})$, EPA $(C_{20:5})$ and DHA $(C_{22:6})$ of wild grape polk. were higher than those of the control. The taste (p<0.001), aroma (p<0.05), flavor (p<0.001), juiciness (p<0.01) and palatability (p<0.01) of wild grape polk. were higher than those of the control, but the texture between control and wild grape polk. were not significantly different.

• Applied Biological Chemistry
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• v.12
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• pp.19-24
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• 1969

As a one of the new methods for soybean protein food processings, an attempt was made to decompose steamed soybean protein to amino acids, peptides, and other water soluble forms by the use of protease produced by Aspergillus sojae, and extract them to use as additives of low protein foods or weaning-foods of children. In this paper, as a one part of this subject, the optimum condition, such as optimum pH, temperature, digestion period, raw material's mixing ratio with wheat meal, amount of water added, and effect of sodium chloride addition, to decompose and extract soybean protein were studied. They were obtained when mixing raw materials with wheat meal in the ratio of 10:4 and adding six folds of water at $40-45^{\circ}C$, pH 5-8 for 18 hrs. digestion. Although sodium chloride addition exerted an unfavorable influence upon the decomposition of the aforementioned materials, it was effective to prolongation of digestion period. Under the abovementioned optimum conditions, the maximum extractability of soybean protein as forms of amino acids, peptides, and other water soluble forms, was nearly 70 percent against protein content of raw materials.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.189-197
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• 2014

Onion juices were prepared by various heat treatments (at $105-120^{\circ}C$ for 4.5-5.5 h), from the onions cultivated with increasing numbers of sulfur applications (once for Sulfur-1, four times for Sulfur-4). As heat treatment intensity increased, the onion juices darkened (p<0.001), which adversely affected the sensory preference. In addition, increasing the heating temperature significantly increased the organic acid content of onion juices (p<0.001), and therefore, decreased pH (p<0.001). Heat intensity did not affect the thiosulfinate content of onion juices, suggesting that the rate of decomposition of thiosulfinate into low-molecular weight sulfur derivatives is similar over the temperature range of $105-120^{\circ}C$. Total flavonoids were higher in onion juices derived from Sulfur-4 than in Sulfur-1 onions, and increased with heat treatment intensity (p<0.001). These results indicated that heat-facilitated conversion of bound forms of flavonoids to their free forms increases the extractability of flavonoids from onions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.3
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• pp.207-211
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• 1983

An attempt was made to find out the possibility of utilizing water-melon seed as resources of food fats and protein. The water-melon seed contained 40.40% of crude fat and 28.36% of crude protein. The lipid fraction obtained by silicic acid column chromatography was composed of about 97.35% neutral lipid, and the main components of neutral lipid by thin layer chromatography were triglyceride(50.40%), diglyceride(21.84%) and sterol(11.48%). The predominant fatty acids of total and major lipid classes were linoleic acid(55.30-67.85%), palmitic acid(12.07-28.12%) and oleic acid(9.06-16.40%), whereas stearic acid and linolenic acid were detected as small amounts. The salt soluble protein of watermelon seed was highly dispersible in 0.02M sodium phosphate buffer containing about 0.7M $MgSO_4$, and the extractability of seed protein was about 27%. Glutamic acid and arginine were major amino acids, and the essential amino acids such as lysine, threonine, valine, methionine, isoleucine, leucine and phenylalanine were also detected. The electrophoretic analysis showed 6 bands in water-melon seed protein, and the collection rate of the main protein fraction purified by sephadex G-100 and G-200 was 52.4%. The amino acids of the main fraction protein were also mainly composed of glutamic acid and arginine. The molecular weight for the main protein of the water-melon seed was estimated to be 120,000.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.55-61
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• 1987

This study was carried out to investigate the changes in the pH, extractability of protein, ATPase activity of myofibrillar protein, myofibrillar fragmentation, freezing loss and drip loss during storage at $4^{\circ}C$ and $-20^{\circ}C$ in breast and leg muscle of spent-hen meat. pH values ill pectoral and leg muscle were lowest ell tile 1st day and 1st week during cold and frozen storage, respectively. The extractabilities of myofibrillar proteins were increased graduall during cold storage and were highest on the 1st week during frozen storage, The $Mg^{2+}-ATPase$ activities of myofibrillar proteins were highest on the 1st day and 1st week during cold and frozen storage, respectively. The myofibrillar fragmentations were greatly changed on the 1st day during cold storage and 1st week during frozen storage. Freezing losses and drip losses were increased gradually during frozen storage. pH values in breast muscle were lower than those of leg muscle, and the extractabilities, $Mg^{2+}-ATPase$ activities, fragmentations of myofibrillar proteins, and drip losses in breast muscle were higher than those of leg muscle during storage, but the patterns of the changes in both muscles were similar during storage.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.319-325
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• 1985

Agar was prepared from domestic agarophyte (Gelidium amansii) by a process of acid extraction. Optimal conditions in the acid treatment of the seaweed and the gelling properties of the agar thus prepared were investigated. The yield and gel strength of the control (the agar extracted with distilled water) showed 13,3% and 306g/$cm^2$, respectively. The yield of 38.7% was obtained when agar was extracted with 0.007N Hydorchloric acid while the gel strength of agar,511g/$cm^2$ was observed with the agar extracted with 0.005N Hydorchloric acid solution. The agar extracted with hydrochloric acid solution showed excellent properties of agar at the acid concentration range 0.005N-0.01N The cooking time of 60 min. was found to be effective to the yield and also to the gelling property of the agar and the cooking longer than 60 min. was proved to be destructive to agar. In general, yield and gelling properties of the agar obtained showed a close relation to the acid concentration and cooking time, but no consistent influence on the contents of ash and sulfur trioxide.

• Resources Recycling
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• v.25 no.3
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• pp.11-19
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• 2016

A fundamental study to recycle a Si-Sludge and waste copper nitrate solution acid solution generated by domestic electronic industries was carried out. The waste copper nitrate solution was used as the lixiviant to leach the metals like Cu, Ca, Fe, etc. from the sludge leaving Si in the residues. The effect of reaction temperature, time and pup density on the metals leaching from the sludge was investigated. To enhance the extractability of Fe, the effect of HCl, $HNO_3$ and $H_2O_2$ introduced additionally during the leaching was also examined. Considering the leaching efficiency of Fe along with Cu, the leaching conditions comprising of 200 ~ 225 g/L pulp density and $90^{\circ}C$ temperature for 30 min were optimized. Under this condition, 98.27 ~ 99.17% Cu could be dissolved in the leach liquor with the obtained purity of Si in the residues as 98.69 ~ 98.86 %. The study revealed that the leaching of Cu contained in the Si-Sludge with the waste copper nitrate solution is a plausible approach by which the obtained leach liquor can further be treated suitably to recover Cu as the high pure value-added products.

• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.128-132
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• 1983

The apple seed contained 25.96% of crude fat and 37.62% of crude protein. The lipid fractions obtained by cilicic column chromatography were mainly composed of about 93.52% neutral lipid, whereas compound lipid was only 6.48% level. Among the neutral lipid separated by thin layer chromatography, triglyceride was 92.17%, sterol ester, sterol, diglyceride and free fatty acid were 3.53, 2.25, 1.44 and 0.56, respectively. The predominent fatty acids of total and neutral lipids were linoleic acid (59.79-69.37%) and oleic acid (20.04-29.82%), but those of glycolipid and phojspholipid were linoleic acid (29.20-36.04%). The major fatty acids of triglyceride separated from neutral lipid were oleic acid (44.31%), linoleic acid (36.66%) and palmitic acid (12.48%). The salt soluble protein of apple seed was highly dispersible in 0.02M sodium phosphate buffer containing about 1.0M $MgSO_4$, and the extractability of seed protein was 37%, Glutamic acid was the major amino acid in salt soluble protein, followed by arginine and aspartic acid. The eletrophoretic analysis showed three bands in apple seed protein, and the collection rate of the main protein fraction purified by Sephadex G-100 and G-200 was 76.6%. Glutamic acid, aspartic acid and arginine were the major amino acids of the main apple seed protein. The molecular weight for the main protein of the apple seed was estimated to be 45,000.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.1
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• pp.46-50
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• 1983

In order to find out the possibility of utilizing red pepper seed as food resources of fats and proteins, a series of studies were conducted. The red pepper seed contained 27.6% of crude fat and 22.2% of crude protein. The lipid fractions obtained by silicic acid column chromatography were mainly composed of 95.4% neutral lipid, where as compound lipid were 4.6%. Among the neutral lipid separated by thin layer chromatography, triglyceride was 85.6%, sterol ester 4.9%, free fatty acids 3.4%, diglyceride 2.5%, sterol 2.2% and monoglyceride 1.1%, respectively. The predominant fatty acids of red pepper seed oil were linoleic acid (57.1-75.4%), palmitic acid (13.9-21.3%) and oleic acid (8.0-15.1%), especially glycolipid contained 1.7% of linolenic acid and small amount of myristic acid and arachidic acid. The salt soluble protein of red pepper seed was highly dispersible in 0.02M sodium phosphate buffer containing 1.0M $MgSO_4$, and the extractability of seed protein was about 25.0%. Glutamic acid and arginine were major amino acids of red pepper seed protein. The electrophoretic analysis showed 6 bands in seed protein, and the collection rate of the main protein fraction purified by sephadex G-100 and G-200 was about 62.2%. Glutamic acid (19.9%) was major amino acid of the main protein, followed by glycine and alanine. The molecular weight of the main protein was estimated to be 93,000.