• Applied Biological Chemistry
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• v.36 no.3
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• pp.163-171
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• 1993

The collagens from filefish (Novoden modestus) and cod (Gadus macrocephalus Tilesius) skin were isolated and their physicochemical properties were investigated. Glutamic acid, hydroxyproline, valine and phenylalanine in the filefish skin collagen (FSC) were presented at higher levels than those of cod skin collagen (CSC), but the contents of glycine, proline and serine were contrary. The content of essential amino acids of FSC (265 residues/1000 residues) was higher than CSC (229 residues). The solubilities of both collagens were the lowest at pH 7.0, but precipitously increased at acid zone(below pH 5.0). FSC has lower viscosity than CSC. Furthermore, while the viscosities of both collagens were the lowest at pH 7.0, the viscosities of FSC and CSC were the highest at pH 4.0 and pH 2.0, respectively. The denaturation temperature of $FS(25^{\circ}C)$ was higher than $CSD\;(17^{\circ}C)$. The free hydrophobic residue contents of FSC and CSC tended to increase till $60^{\circ}C,\;and\;50^{\circ}C$ respectively, and to decrease thereafter. Hydration capacities of both collagens were the lowest at pH 7.0, and CSC had the superior hydration capacity to FSC. In addition, emulsifying and emulsifying stability of CSC was also superior to FSC.

• Food Science of Animal Resources
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• v.29 no.3
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• pp.356-363
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• 2009

This study was carried out to investigate the effect of hot boning and curing condition on the quality characteristics of ground chicken breast. Treatments were cured by four conditions follows; control (general curing method), T1 (after hot-boning and then immediately cured), T2 (after hot-boning and immediately cured, then frozen), and T3 (after hot-boning, immediately frozen, refrigerated and then cured). The pH of chicken breast in the state of pre-rigor was 6.22. The pH of cold storage or freezing chicken breast meat respectively were 5.70 or 5.61. The pH of T1 and T2 treatments were significantly higher than those of control and T3 treatment (p<0.05). After stored for 1 wk, the pH value of T1 treatment had a higher value than those of other treatments. T1 treatment had the highest water holding capacity and the lowest cooking loss among all treatments, regardless of the cooking methods. The reduction in diameter for T1 and T2 treatments was lower than those of control and T3 treatment (p<0.05). T1 treatment had the lowest fat loss and moisture loss among all treatments, and the emulsifying capacity of T1 treatment was the highest. The protein solubility of T1 treatment was significantly lower than that of T3 treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.82-89
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• 1998

Partial hydrolyzing condition for low-molecularized alginate and rheological properties such as viscosity, solubility, emulsitying ability, oil absorption capacity, bile acids binding and metal ion binding of the low-molecularized alginates from the sea mustard ( Undaria pinnatifida) and giant kelp (Macrocystis pyrifera) were investigated. Alginate from sea mustard was regularly hydrolyzed with the increase of HCl concentration in the range of 0.2 N to 0.5 N and with the prolonged reaction time at $100^{\circ}C$. The molecular weight of alginate was decreased to a part of 100 after hydrolysis for 50 min with 0.3 N HCl. The ratio of mannuronate to guluronate was increased with the acid hydrolysis and total yield was estimated to be $75\%\~80\%$. Low-molecularization of alginate was featured in the apparent decrease of viscosity, whereas solubility, emulsifying ability, and bile acids binding ability were increased with the low-molecularization. Oil absorption capacity of the acid$\cdot$alkali soluble alginate was slightly higher than that of the water soluble alginate. Metal ion binding capacity was the highest in acid$\cdot$alkali soluble alginate, and decreased with the low-molecularization.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.1
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• pp.7-20
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• 2023

Boil-dried concentrate (BDC) and steam-dried concentrate (SDC) were prepared from olive flounder Paralichthys olivaceus roe using the cook-dried process, and their food functionality and in vitro bioactivity were examined. The buffer capacity of BDC and SDC was found to be stronger in the alkaline region than in the acidic region, and the buffer capacity of SDC was superior to that of BDC. The water holding capacities of these concentrates were 7.6 and 7.4 g/g protein, respectively, both of which were significantly lower than that of freeze-dried concentrate (FDC). The solubility of BDC (13.4%) and SDC (12.7%), foaming capacity of BDC (107.7%) and SDC (110.6%), and oil-in-water emulsifying activity index of BDC (7.7 m²/g) and SDC (9.7 m²/g) were all significantly lower than the corresponding values for FDC (P<0.05). The lower food functionality of BDC and SDC compared with FDC can be attributed to the high-temperature denaturation of proteins during the cook-dried process. The 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activities (IC₅₀) of SDC (2.5 mg protein/mL) was 60.4 ㎍/mL, and the angiotensin I converting enzyme inhibitory activity was 80.9%. Olive flounder roe concentrates have good antioxidant and antihypertensive activities, and can be used as materials or ingredients in the processing of seafood and other foods to enhance protein contents and food functionality.

• Food Science of Animal Resources
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• v.38 no.2
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• pp.315-324
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• 2018

The objective of this study was to evaluate the efficacy of alkaline-treated sugarcane bagasse fiber on physicochemical and textural properties of meat emulsion with different fat levels. Crude sugarcane bagasse fiber (CSF) was treated with calcium hydroxide ($Ca(OH_2)$) to obtain alkaline-treated sugarcane bagasse fiber (ASF). The two types of sugarcane bagasse fiber (CSF and ASF) were incorporated at 2% levels in pork meat emulsions prepared with 5%, 10% and 20% fat levels. Alkaline-treatment markedly increased acid detergent fiber content (p=0.002), but significantly decreased protein, fat, ash and other carbohydrate contents. ASF exhibited significantly higher water-binding capacity, but lower oil-binding and emulsifying capacities than CSF. Meat emulsions formulated with 10% fat and 2% sugarcane bagasse fiber had equivalent cooking loss and textural properties to control meat emulsion (20% fat without sugarcane bagasse fiber). The two types of sugarcane bagasse fiber had similar impacts on proximate composition, cooking yield and texture of meat emulsion at the same fat level, respectively (p>0.05). Our results confirm that sugarcane bagasse fiber could be a functional food ingredient for improving physicochemical and textural properties of meat emulsion, at 2% addition level. Further, the altered functional properties of alkaline-treated sugarcane bagasse fiber had no impacts on physicochemical and textural properties of meat emulsions, regardless of fat level at 5%, 10% and 20%.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.344-349
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• 1988

Proteolysis of 7S and 11S soy protein-rich fraction(PRF) with commercial proteases(alcalase and pronase) apperently increased protein solubility at pH 5, heat coagulation and calcium tolerence, while decreasing emulsifying capacity and foam stability regardless of the kind of protein and protease used. However, the proteolysis decreased the protein solubility of 7S PRF at pH 6 and 11S PRF at pH 4. The proteolysis of 11S PRF increased oil absorption and foam expansion, while slight decrease or almost no change was noted on 7S PRF. Heat stabilities of the emulsion and kinetic viscosities changed very little by the proteolysis.

• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.321-325
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• 1983

This study was carried out to investigate the nutritive value and functional proterties of chloroplastic protein and cytoplasmic protein which are a leaf protein concentrates of acacia. The results obtained are as follows; 1. The limited amino acids of chloroplastic protein and cytoplasmic protein in acacia leaf were methionine & tryptophan in both cases. 2. Digestibilities of chloroplastic protein and cytoplasmic protein were 72.59% and 60.24%, respectively. 3. Bulk density, water absorption, emulsifying capacity and emulsion stability of the chloroplastic protein and cytoplasmic protein were not greatly different from those of milk casein, but water solubilities of those were lower than that of milk casein. 4. Fat absorption of the cytoplasmic protein was similar to that of milk casein, but that of the chloroplastic protein was lower than that of milk casein.

• Food Science of Animal Resources
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• v.34 no.3
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• pp.362-371
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• 2014

This study utilized commercially available proteolytic enzymes to prepare egg-white protein hydrolysates (EPHs) with different degrees of hydrolysis. The antioxidant effect and functionalities of the resultant products were then investigated. Treatment with Neutrase yielded the most ${\alpha}$-amino groups (6.52 mg/mL). Alcalase, Flavourzyme, Protamex, and Ficin showed similar degrees of ${\alpha}$-amino group liberation (3.19-3.62 mg/mL). Neutrase treatment also resulted in the highest degree of hydrolysis (23.4%). Alcalase and Ficin treatment resulted in similar degrees of hydrolysis. All hydrolysates, except for the Flavourzyme hydrolysate, had greater radical scavenging activity than the control. The Neutrase hydrolysate showed the highest 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity ($IC_{50}=3.6mg/mL$). Therefore, Neutrase was identified as the optimal enzyme for hydrolyzing egg-white protein to yield antioxidant peptides. During Neutrase hydrolysis, the reaction rate was rapid over the first 4 h, and then subsequently declined. The $IC_{50}$ value was lowest after the first hour (2.99 mg/mL). The emulsifying activity index (EAI) of EPH treated with Neutrase decreased, as the pH decreased. The EPH foaming capacity was maximal at pH 3.6, and decreased at an alkaline pH. Digestion resulted in significantly higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ABTS radical scavenging activity. The active peptides released from egg-white protein showed antioxidative activities on ABTS and DHHP radical. Thus, this approach may be useful for the preparation of potent antioxidant products.

• Preventive Nutrition and Food Science
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• v.13 no.3
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• pp.204-211
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• 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 Poultry Science
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• v.12 no.1
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• pp.31-38
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• 1985

To learn more about the productivity of edible meat and its functional properties of spent hen, 60 White Leghorn fowls at 20 month of age were randomly divided into 6 groups, 10 hen for each group, and processed. As the productivity of edible meat, the yield of dressed carcass, giblets, cut-up meat, and breast and leg (thigh and drustick) muscles were determined. The approximate chemical composition, the content of salt-soluble protein, the emulsifying capacity and W.H.C. of breast and leg muscle were measured as the functional properties. The results were summarized as follows. 1. The average live weight of spent hen was 1,576.7g from which the yield of dressed carcass and giblets were 998.9g(63.4%) and 75.3g(4.8%) respectively. It means the yield of ready-to-cook form was 1,074.2g(68.2%) and the inedible byproducts was 502.5g (31.8%). 2. The average, weight of each part of cut-up chicken were: neck 41.0g(4.1%), wings 135.9g (13.6%), breast 276.7g (27.7%), legs 323.6g (42.4%). back 176.1g(17.6%) and the cutting-loss was 45.6g(4.6%). 3. The average weight of total edible muscle from breast and leg was 51.5g(85.86% of breast and leg cut weight) and the percentages based on the carcass and live weights were 51.6% and 32.7%, respectively. 4. The contents of H$_2$O, protein, fat and water-protein ratio of breast muscle were 72.95%, 20.54%, 1.59% and 3.55, respectively and those of leg muscle were 71.9%, 19.12%, 3.96% and 3.76%, respectively. 5. The salt-soluble protein contents of breast and leg muscle were 7.97% and 6.26% and their concentrations based on the total protein content were 38.8% and 32.74%, respectively. 6. The emulsifying capacity of breast and leg muscle was 43.23$m\ell$and 43.23$m\ell$, respectively. 7. The W. H. C- of breast and leg muscle was 54.23% and 52.61%, respectively.