• Journal of Applied Biological Chemistry
• /
• v.42 no.4
• /
• pp.180-185
• /
• 1999

Protein concentrate was produced and succinylated from rice bran to assess and improve its functional properties for the purpose of expanding the uses of rice bran proteins. The most effective solvent for the extraction of rice bran proteins was 20% aqueous ethanol at pH 9. The protein content of rice bran protein concentrate produced was 70.0% and the total protein yield was 64.3%. The extent of succinylation of free amino groups in the modified products was 72.8%. Though the modified protein products showed good functional properties including solubility, emulsion properties, and oil absorption capacity, it did not form gel. Succinylation improved solubility and emulsion and gelling properties. These improvements in functionality will enhance the value of rice bran proteins, thus enabling them to be more competitive with other food proteins.

• Preventive Nutrition and Food Science
• /
• v.13 no.3
• /
• pp.204-211
• /
• 2008

Fish protein hydrolysates (FPHs) with different degrees of hydrolysis by treatment with alcalase, pronase, flavourzyme and trypsin and isolated peptide were prepared from Hwangtae (yellow dried pollack, Theragra chalcogramma). Hwangtae protein hydrolysate was fractionated according to the molecular weight into six major types of APO1 (1.3 kDa), APO2 (1 kDa), APO3 (<1 kDa), APACE (<1 kDa), APG1 (70 kDa) and APG2 (70 kDa) isolated from the hydrolysate using consecutive chromatographic methods. Soluble peptide were produced from Hwangtae and evaluated for their nutritional and functional properties. Some functional properties of FPHs were assessed and compared with those of egg albumin or the soybean protein. APO2 had the highest nitrogen solubility value (94.2%), emulsion capacity and emulsion stability of the Alaska Pollack peptide ranged from 12.4 to 39.5 (mL of oil per 200 mg of protein) and 44.0% to 77.5%, respectively. Highest and lowest fat adsorption values were observed for APG1 (9.9 mL of oil per gram of protein) and APO3 (3.8 mL of oil per gram of protein), respectively.

• Korean Journal of Food Science and Technology
• /
• v.19 no.6
• /
• pp.499-505
• /
• 1987

The functional properties of lupin seed protein concentrate (LPC) were examined and compared to those of soybean protein isolate (SPI) and Na-caseinate. LPC-50, of which protein level was 50%, was prepared by a two phase solvent (hexane: alcohol: water= 10:7:3) extraction method. LPC-70 was made from LPC-50 by removing the fractions solubilized by carbohydrate decomposing enzymes. The solubilities of LPC-50 and LPC-70 were similar to that of of SPI but slightly higher at pH 4-5, and less susceptible to the added salt. The apparent viscosity of LPC increased exponentially as the concentration increased over 6% level, and the change was similar to that of Na-caseinate. LPC showed strong pseudoplastic non-Newtonean flow behavior, which was similar to that of SPI The emulsifying capasity of LPC-70 was similar to that of SPI when salt was added. The foaming capacity of LPC was comparable to that of SPI. LPC showed high oil and water absorption capacities, which increased as the protein level was elevated. LPC-70 showed the highest oil absorption capacity of all the samples tested.

• Korean Journal of Food Science and Technology
• /
• v.28 no.3
• /
• pp.506-513
• /
• 1996

Soybean hull was microparticulated at cut-off wheel speed of 9,000 rpm and air-classified into fine and coarse fraction at air classifying wheel speeds (ACWS) of 10.000, 15,000 and 20,000 rpm. respectively. Proximate analysis of the coarse and fine fractions of the microparticulated/air-classified soybean hull showed that ash, protein and lipid were enriched in the coarse fractions and carbohydrates in the fine fraction. Dietary fiber were enriched in coarse fractions and dietary fiber and dietary fiber content increased with decreasing ACWS. Mean particle size of fine fractions ranged from $3.1{\mu}m\;to\;5.5{\mu}m$ that of coarse fractions ranged from $9.9{\mu}m\;to\;20.0{\mu}m$ and both increased with decreasing ACWS. The particles were mostly oval-shaped regardless of the fractions. Generally the fraction of low ACWS showed higher viscosity. In water holding capacity, oil absorption and emulsion capacity, there was significant difference between coarse and fine fractions while there was no significant difference as a function of different ACWS. Oil absorption of flying batter was decreased significantly in the fraction of ACWS 15,000. when cakes and cooking were prepared partially substituted with soybean hull fraction, there was no significant changes on their physical and sensory properties up to 10% substitution.

• Korean Journal of Food Science and Technology
• /
• v.27 no.6
• /
• pp.997-1002
• /
• 1995

In order to study the effects of reaction temperature, time and particle size on the physicochemical properties of chitosan, commercially available chitin was treated with 50%(w/w) NaOH. To obtain 78% of deacetylation, a treatment of 6 hours at $100^{\circ}C$(Ch-100), 20 minutes at $120^{\circ}C$(Ch-120) or 10 minutes at $140^{\circ}C$(Ch-140) was necessary. The resulting chitosans showed a different viscosity; 180cps for Ch-100, 130cps for Ch-120, 30cps for Ch-140. The residence time at $80^{\circ}C$ also decreased the viscosity of the chitosan but the reduction in the particle size of chitin largely favored deacetylation and resulted in a higher viscosity of the chitosan. Compared with chitin, the capacity of water and oil absorption of chitosan was not significantly improved. However, the capacity of dye absorption was increased by 4 times by the deacetylation. In addition the IR spectra of chitosans showed less sharp absorption bands than that of chitin.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.7 no.1
• /
• pp.43-52
• /
• 1978

It is well known that water holding capacity plays an important role in processing such meat products as frankfurter-type sausage and fish meat paste products as kamaboko and fish sausage. Consumer qualities of meat products, such as appearance, flavor, as well as drip and shrinkage on cooking, depend greatly on the degree of water binding. In this paper, the water holding capacities of fish paste and salt added paste of white corvenia, Argyrosomus argentatus and file fish, Novodon modestus were measured by centrifuging and press method before and after cooking. And the effects of the addition of phosphates and starch to enhance water binding and stabilize gel formation were also discussed. In addition, the experimental conditions which are suitable to determine the water binding of fish meat paste product were suggested. The results were expressed in percent of water absorbed by the filter paper when pressed or released by pressor or centrifuge to the weight of sample. From the results. a proper condition to measure the water holding capacity of fish meat paste was that 3.0 g of sample which was previously added with 10 percent water was centrifuged at 13,400 G or 12,000 rpm for 15 minutes for the centriguging method and for press method, 0.3 g sample with 10 percent of water added was extracted by an oil pressor at $30\;kg/cm^2$ for 1 minute. Water holding capacity of fresh paste of white corvenia was relatively higher than that of file fish and the difference between species of fish was greater than the difference between measurments by two methods. Sodium chloride had a great effect on enhancing the water holding capacity of fish meat paste giving better effect when 3.0 percent of salt was added. Phosphates used except calcium phosphate revealed a certain enhancement in water binding, yielding best effect at 0.3 percent addition, and metaphosphate seemed to be more effective in order. The addition of corn starch, however, appeared to be not so effective for enhancement of water binding in fresh-salt-added fish meat paste but in cooked fish paste which might be attributed to absorption of water by starch grain and swelling during the heating and consequently enforced gel strength of cooked fish paste. And the water holding capacity of cooked fish paste was proportionally related to its gel strength.

• Journal of the East Asian Society of Dietary Life
• /
• v.25 no.6
• /
• pp.1049-1057
• /
• 2015

This study investigated the physicochemical properties of Dioscorea batatas for improvement of biological activities during a three-step steaming process, steaming $120^{\circ}C$ for 30 min and hot air drying at $60^{\circ}C$ for 8 hrs. Samples were extracted with 70% ethanol and analyzed for free sugars, and organic acids were analyzed by HPLC. The DPPH & ABTS radical scavenging activities, crude saponin, water binding capacity, oil absorption, and ${\alpha}$-glucosidase activity were measured. The major free sugars in all samples were fructose, maltose, and sucrose, and the free sugar contents increased to 157~235% after the three-step steaming process compared to the control. Organic acid contents of samples treated by steaming increased to greater than 55.8 mg/100g. The ABTS radical scavenging activity significantly increased with repeated steaming process, especially after the three-step process. As the time of steaming process increased, DPPH radical scavenging activity increased from 26.99% fresh Dioscorea batatas to 80.46~97.79% after the three-step process. Crude saponin content increased rapidly as steaming time increased, but decreased after the three-step process steaming process. The water-binding capacities of the samples treated by steaming process were higher than that of the control, whereas oil absorption decreased as steaming time increased. From the results, steaming process could be suggested as beneficial for controlling fat intake. Compared to acarbose, a known antidiabetic drug, used as a positive control, ${\alpha}$-glucosidase inhibitory activity of samples treated by two-step steaming was among the samples. The results suggest that Dioscorea batatas treated by steaming process has antioxidative and anti-diabetis activities and can be used as a natural health product.

• Korean journal of food and cookery science
• /
• v.32 no.1
• /
• pp.50-57
• /
• 2016

In this study, kim (dried laver) bugak ("KB"), Aster yomena bugak ("SB"), and namul (vegetables)-kim bugak (combination of Aster yomena and kim) ("NB") were prepared and their quality characteristics were investigated. NB was made by slicing Aster yomena, seasoning it with perilla seeds, attaching it to kim and applying glutinous rice paste, followed by freeze-drying. SB had a higher oil absorption rate than KB, reflecting the high oil absorption rate of namul (here, Aster yomena). DPPH radical scavenging activity was highest for SB; whereas, NB had higher DPPH radical scavenging activity than KB, indicative of the higher antioxidant capacity of namul, as compared to kim. With longer storage period, moisture content tended to be increased, while maximum load, yield stress and hardness tended to be decreased. Overall preference was in the order of NB>KB>SB, without statistical significance. Acid value and peroxide value of NB, stored at $25^{\circ}C$ for 40 days, tended to be increased gradually but did not meet the criteria for rancidity. Therefore, NB could be stored at $<25^{\circ}C$ for > 40 days. Furthermore, it would be possible to make functional bugak using a variety of namul, as well as Aster yomena.

• Korean Journal of Food Science and Technology
• /
• v.27 no.3
• /
• pp.394-403
• /
• 1995

Various thermal treatments such as toasting, roasting, drum drying, autoclaving+drum drying, microwaving+drum drying and extrusion were attempted to investigate their effects on chemical composition (proximate composition, Klason lignin, neutral sugar, uronic acid, starch, free sugar, dietary fiber, phytic acid, etc) and functional properties (water solubility index, water absorption index, water holding capacity, oil holding capacity, bulk density, swelling, etc) of wheat bran. Thermal treatments on wheat bran increased soluble dietary fiber (SDF) content from 2.7% (raw sample) to 4.6% (toasted), 4.5% (roasted), 4.6% (drum dried), 5.2% (autoclaved), 3.7% (microwaved), 5.6% (extruded). In contrast, total dietary fiber (TDF) content remained nearly constant regardless of thermal treatments, reflecting the concomitant decrease in insoluble dietary fiber (IDF). It was also found that water holding capacity (WHC) increased $20{\sim}75%$ due to thermal treatments employed in this research. Both bulk density and swelling were not directly relevant to WHC, but thier multiplication exhibited good correlation $(R^2=0.94)$ with WHC. Scanning elctron microscopy (SEM) exhibited that structure of raw wheat bran was significantly modified, whose degree and shape well reflected the types of thermal treatments.

• Applied Biological Chemistry
• /
• v.36 no.3
• /
• pp.172-177
• /
• 1993

To extract insoluble proteins from sesame meal residue by microorganism, the sesame meal residue was treated with crude enzyme solution of Bacillus sp. CW-1121. The foaming capacity of salt soluble protein was quite lower than that of water soluble protein and the foaming stability of salt soluble protein decreased abruptly in 10 min., while it sustained for 30 min in case of water soluble protein. Emulsion capacities of all the protein fractions showed minimum value near isoelectric point of protein and salt soluble protein had lower emulsion capacities than that of water soluble protein. The emulsion stability of the protein was relatively stable for 30 min at $80^{\circ}C$. Oil and water absorption capacities of salt soluble protein were higher than those of water soluble protein.