• Korean Journal of Food Science and Technology
• /
• v.2 no.2
• /
• pp.8-16
• /
• 1970

Exploitation of leaf protein concentrates for human consumption is very important. Leaf protein concentrates can be easily prepared by mechanically mincing leaves material and press it for getting the juice. Crude protein can be separated from the juice by aging, adjusting the pH, or heating to $75-80^{\circ}C$ etc. This report deals with the extractability of total-N from 69 species of fresh leaves by mechanical process, and then compared the recovery of leaf protein concentrates from leaf extracts by treating with TCA, pH adjustment and heating. Results are summarized as follows. 1. In general, the greater the content of total-N of leaves the greater the percentage extraction. Extraction of the juice from leaves is needed at least two times. The simple equations are constituted between the total-N (T; %) and the first and second extractability ($E_1,\;E_2;\;%$) of the total-N of leaves, as follows: $E_1=0.8168T\;E_2=0.1830T$ 2. The optimum pH value for coagulating protein from extracts is considered to be 3.5 to 4.5. However, the products of leaf protein concentrate by the pH adjustment of extracts are generally dull in color with rich elasticity. 3. Recoveries of the leaf protein concentrate from extracts by treating methods were in the following order of TCA treatment> pH 4 treatment> pH 3 treatment> heat treatment. The yield of leaf protein concentrates decreased bout 10% with pH 4 treatment, 11.4% with pH 3 treatment, and 14.8% with heat treatment compared with the TCA treatment. 4. The heat treatment is the most benifitial method for the production of leaf protein concentrates with regard to properties of texture, color and yield of products and easiness of the treatment method.

• Applied Biological Chemistry
• /
• v.33 no.2
• /
• pp.147-153
• /
• 1990

To investigate the effect of spice oils on the nitrite role in processed meat products, eight spice oils, ascorbic acid, and nitrite at different combinations were added to marcerated pork, and cooked at $70^{\circ}C$ lot 30min or $121^{\circ}C$ for 15min. The cooked sample were stored at $5.5^{\circ}C$ for 12days and pH, residual nitrite, redness, TBA value, and antimicrobial activity were analyzed. pH of the uncooked samples were stable at $5.6{\sim}5.8$ except in samples with nitrite alone, anise, ascorbic acid, and black pepper in which pH increased to $6.7{\sim}7.8$ after 5 days of storage. The pH of the cooked samples were stable at $5.9{\sim}6.1$ during the storage. Residual nitrite decreased rapidly on the first day of storage in each model. Residual nitrite decreased rapidly on the first day of storage in each model. The nitrite reducing effect was greatest in sample with ascorbic acid, followed by clove eugenol and thyme, but was small with peppermint. The redness of the sample was increased with ascorbic acid, colve, eugenol, thyme, anise, black pepper, coriander and rosemary except peppermint, specially samples with ascorbic acid, clove and eugenol were prominent. The TBA values of the samples with cloves, eugenol and ascorbic acid, stored after nine days, were $4{\sim}6.5$ lower than that of nitrite added sample and indicated strong antioxidant activity. The antimicrobial activity determined by inhibition zone, was strong in samples with clove, eugenol, peppermint, thyme, coriander, black pepper, rosemary and anise had antimicrobial activity to the Penicillium sp. Specially with clove, eugenol, peppermint and thyme, while all the samples showed $7{\sim}10mm$ inhibition zone to the Salmonella sp. The above results suggest that addition of eugenol, clove and thyme oil to the processed meat may increased the antioxidant, antimicrobial activity, and redness of the product so that could provide a way of reducing nitrite addition into meat products.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.22 no.1
• /
• pp.25-35
• /
• 1989

To prepare a new type of fish sauce from skipjack scrap, it was examined the effect of koji on the sauce flavor, conditions of low salt fish sauce processing and the changes of taste com-pounds during its fermentation. To prepare the skipjack scrap sauce, chopped skipjack head paste was mixed with $6.6\%$ skipjack viscera, $26.9\%$ koji, $71\%$ of $25\%$ brine, $13.3\%$ salt and $7.6\%$ glucose, and fermented at $25\pm4^{\circ}C$ for 90 days. The same process was also carried out to prepare the low salt skipjack scrap sauce adding $7.6\%$ sorbitol, $0.3\%$ lactic acid and $9.8\%$ ethyl alcohol instead of $13.3\%$ salt. The major free amino acids in the products were glutamic acid, Iysine, valine, phenylalanine, alanine, leucine and isoleucine at 90 days of fermentation. And the contents of total free amino acids in both products were 3,307mg/00m1, 3,637.1mg/100m1 at 90 days of fermentation. The predominating non-volatile organic acids showed in the products were lactic acid, succinic acid, pyroglutamic acid, which were $90\%$ over contents of the total non-volatile organic acids. Total non-volatile organic acid contents in both products were 1,002.1mg/100ml, 1,312.9mg/100m1 at 90 days of fermentation. During fermentation of sauce, ADP, AMP and IMP were decreased, while inosine and hypoxanthine were increased. The major taste compounds of the products were rove진ed free amino acids and non-volatile organic acids. The nucleotides and their related compounds, total creatinine, betaine, TAMO and sugar were seemed to be having an auxiliary role in taste of those products. Fishy odor in skipjack scrap sauce can be improved by adding koji. And the low salt skipjack scrap sauce ($9.12\%$ of salt contents) can be prepared by the replacement of a part of salt with sorbitol, lactic acid and ethyl alcohol. From the results of sensory evaluation and chemical experiments, the skipjack scrap sauce products supposed to be at least equal to the sold soy sauce on the market in quality.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.2
• /
• pp.170-174
• /
• 1999

Proessing conditions for fermented and dried sauces with the underutilized fishes were investigated. Hair tail, gizzard shad, and kangdale were hydrolyzed at $60^{\circ}C$ for 6 hours using $4\%$ Alcalase, and their hydrolysates were separted by molecularporous membrane. The hydrolytic ratios of hair tail, gizzard shad, and kangdale were estimated to be $84.2\%$, $83.6\%$ and $85.1\%$, respectively. Amino nitrogen recoveries were determind to be $73.1\~73.9\%$ by a membrane with molecular weight cutoff 100 dalton and $91.7\~92.5\%$ by a membrane with 500 dalton. Ultrafiltration was very efficient means for removing bitter taste. With the additions of $2\%$ glucose, $4\%$ lactose and $4\%$ skim milk, product yields of hair tail, gizzard shad, and kangdale were determind to be $16.4\%,\;17.2\%$ and $17.0\%$, respectively. Water adsorption rates of hair tail and kangdale showed $5.0\~9.2\%$ and $5.5\~9.6\%$, respectively, under Aw 0.52$\~$0.94. Contents of total nitrogen in the fermented and dried sauces prepared with hair tail, gizzard shad and kangdale were $3.9\%,\;4.1\%$ and $3.7\%$, respectively, and those of amino nitrogen were $3.2\%,\;3.4\%$ and $3.1\%$, respectively. In the fermented and dried sauces prapared with hair tail, gizzard shad and kangdale, the hygroscopities at Aw 0.88 were $6.9\%,\;7.5\%$ and $6.8\%$, respectively, and solubilities under dissolved in water for 30 minutes were $84.6\%,\;83.6\%$ and $93.8\%$, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.3
• /
• pp.357-368
• /
• 1996

To utilize the ascidian tunic as a natural pigment and dietary sources for rainbow trout (Oncorhynchus mykiss), juvenile were fed on experimental diets containing enzymatic hydrolysates of ascidian tunic treated with three commercial mined enzymes (ultrazyme, cellulase, viscozyme) for 12 weeks. From the results of feeding experiment, similar growth rate was checked in the enzymatic hydrolysis group compared with control, and those were a higher than of ascidian tunic powder group. The total acetone extractable pigment in muscle of the enzymatic hydrolysates group was lower than that of the ascidian extracts group and carophyll pink group until 8 weeks, but the level of those pigment of the enzymatic hydrolysates was similar to the ascidian extracts and carophyll pink group after 12 weeks. The lipid content was increased with the pigment concentration in the all experimental group. But the ascidian tunic pigment did not influence on the composition of the fatty acids in the muscle and liver. From the consideration of results for pigmentation, the enzymatic hydrolysates of ascidian tunic were suitable for both a natural pigment and dietary protein and carbohydrates sources as a substitute synthetic pigment for aquaculture use.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.13 no.1
• /
• pp.97-106
• /
• 1984

The Antarctic krill, Euphausia superba, is drawing attention over the world as the largest source of unutilized proteins in the ocean. For the use of krill as a human food, processing conditions of krill sauce by autolysis and/or commercial proteolytic enzyme digestion were examined. The krill was chopped and mixed with equal weight of water, and hydrolyzed by autolysis and/or commercial proteolytic enzyme digestion. The optimal conditions for hydrolysis of krill were $52.5^{\circ}C$, pH 7.0-7.5, 3 hours by autolysis, $52.5^{\circ}C$, pH 6.3, 3hours by bromelain (0.5 %) digestion, and $52.5^{\circ}C$, pH 7.0-7.5, 3 hours by commercial complex enzyme (5 %) digestion, respectively The maximum hydrolyzing rate of protein were 83.2 % by autolysis, 89.7 % by bromelain digestion, 92.7 % by commercial complex enzyme digestion. After krill meat hydrolyzed by autolysis at optimum condition, inactivated at $100^{\circ}C$ for 20 minutes and filtered with Buchner funnel. Two kinds of products were prepared with krill hydrolysate and preservatives: one contained 10 % of sodium chloride and 0.06 % of benzoic acid and the other 10 % of sodium chloride and 3 % of ethyl alcohol. These products were filled in the sterilized glass bottle and sealed. The pH, volatile basic nitrogen, amino nitrogen, color value (L, a and b values) and viable counts of bacteria were determined during storage at $37^{\circ}C$. The results showed that the products could be preserved in good condition during one month at $37^{\circ}C$. As a method to reduce the sodium level in krill sauce, it is convinced that sodium chloride could be replaced half in partially by potassium chloride. In the products prepared from krill by autolysis, bromelain or commercial complex enzyme digestion, hypoxanthine and 5'-IMP were abundant among the nucleotides and their related compounds as 15.3-20.4 ${\mu}mole/g$, dry solid, 2.2-2.5 ${\mu}mole/g$, dry solid, respectively. The abundant free amino acids were lysine, leucine, proline, alanine and valine. The contents of these amino acids were 67.4 %, 69.4 %, 69.8 % of the total free amino acids of each products. And TMAO, betaine and total creatinine were low in contents. The flavor of krill sauce prepared from krill by autolysis or enzyme digestion was not inferior to that of traditional Kerean soy sauce by sensory evaluation.

• Food Science and Preservation
• /
• v.21 no.2
• /
• pp.187-192
• /
• 2014

This study was conducted to develop a salad dressing using jujube (Zizyphus jujuba Miller) puree and to evaluate the processing and quality characteristics of the salad dressing containing various amounts (0, 10, 20, 30, 40, and 50%) of jujube puree. Jujube puree was prepared by crushing peeled, deseeded and steamed fruit flesh. The dressing ingredients (jujube flesh puree, soy sauce, vinegar, oligosaccharide, olive oil, and water) were mixed, homogenized, and packaged in glass bottles. The quality characteristics (color property, total titratable acidity, soluble solids, viscosity, phenolic compound content, antioxidant activity, and sensory acceptability) of the dressing were analyzed. The lightness ($L^*$) and redness ($a^*$) of the dressing tended to increase as the amount of the jujube puree increased whereas the hue angle ($h^{\circ}$) decreased. The total titratable acidity, soluble solids, viscosity, phenolic compound content, and antioxidant activity of the dressing increased with the addition of more jujube puree. The sensory acceptability (color, smell, taste, texture, and overall acceptability) were significantly higher in the dressing added with 30% added jujube puree than in the other samples. The results show that jujube flesh puree (approximately 30%) can be utilized as an additive for preparing a dressing with simultaneously high antioxidant activity and acceptability.

• Journal of Fisheries and Marine Sciences Education
• /
• v.27 no.4
• /
• pp.1084-1091
• /
• 2015

Aquaculture of olive flounder started in the middle of 1980's and now farming has been taken place in many places along the coastal line in Korea. The taste of olive flounder has a good chewy texture because of high collagen content, low fat content, so it is popular for sliced raw fish. Olive flounder is popular among Koreans but the consumption pattern is uniformly so as to be used as sliced raw fish but not other ways. So, now there needs to develop high valued-processed food using olive flounder. This study was set to investigate the processing of terrine by using olive flounder, in which terrine is French style meat loaf that is well favored around the world. In this study, terrine was prepared by chopping olive flounder meat with 39 g egg white and 10 mL fresh cream (per 50 g fillet) and then seasoned with 5 mL lemon juice, 5 mL brandy, 0.05 g salt and 0.05 g pepper. The 25 g of dough was placed on a vinyl wrap, put with 2 g cheese, and layered an another 25 g dough, and then rolled up and wrapped by aluminium foil. Two different cooking methods were used for terrine processing in this study. Terrine-1 was cooked by vacuum sealed in polyethylene film ($20{\times}30{\times}0.05mm$) after boiling for 5 min and stored at $-20^{\circ}C$ for 7 days. Terrine-2 was prepared by vacuum sealed in polyethylene film ($20{\times}30{\times}0.05mm$) and stored at $-20^{\circ}C$ for 7 days. After 7 days, Terrine-1 was thawed and then heated up in microwave for 2 min (Sample-1), while Terrine-2 was thawed and then boiled in water for 5 min (Sample-2). Viable bacterial count, chemical composition, pH, salinity, hardness, TBA, free amino acid content, and sensory evaluation were measured for both Sample-1 and Sample-2. Especially, the scores of sensory evaluation of Sample-2 is slightly higher than that of Sample-1. On the other hand, there were no significant differences on color, odor, taste, texture, and overall acceptance between Sample-1 and Sample-2.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.1
• /
• pp.87-95
• /
• 2006

Nutritional quality of accelerated salt-fermented anchovy sauce using shrimp processing byproduct as fermenting aids was characterized and compared with commercial anchovy sauce. Four types of sauces were fermented with 0 and $10\%$ addition of shrimp byproducts ($24{\pm}2^{\circ}C$, for 270 days), and 20 and $30\%$ addition of those ($24{\pm}2^{\circ}C$, for 180 days), respectively. Extractive nitrogen content (1,431 to 1,569 mg/100g) of anchovy sauces increased as additional ratios of shrimp byproduct increased. According to the results of ommission test, the taste of all anchovy sauces was influenced by the content of free amino acids, such as mainly glutamic acid and aspartic acid. Regardless of additional ratios of shrimp byproducts, all sauces were similar in total amino acid content ($9,848\~10,324$ mg/100 g), which were 2 times higher compared to that of the commercial sauce. Proline, valine and histidine contents of sauces tend to decrease as the additional ratios of shrimp byproducts increased, whereas methionine, isoleucine, leucine, phenylalanine and lysine contents increased. Increase of some amino acids and mineral content of sauces by increasing of additional ratios was due to release from shrimp byproducts. Sensory evaluation showed that scores of color, flavor and taste of the sauce added with $20\%$ shrimp byproducts_were significantly higher than those of other sauces (p<0.05). In the useful utilization aspects of seafood processing byproducts, shrimp byproducts were good resource for accelerated fermentation and nutritional improvement in preparation of fish sauce.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.5
• /
• pp.535-540
• /
• 2009

The effect of cellulolytic (Viscozyme) and pectolytic (Pectinex) enzyme treatments on extraction of total polyphenol and antioxidant activity of extract from apple peel have been examined. Extraction was carried out with a dosage of 0.1, 0.25, 0.5, 1 and 2% (v/v) of Viscozyme, Pectinex and Viscozyme+Pectinex at $30{\sim}50^{\circ}C$ for $12{\sim}24$ hours. Total polyphenol contents (mg/mL) of extracts obtained with 2% of Viscozyme, Pectinex or Viscozyme+Pectinex treatment for 12 hours were $0.30{\pm}0.02$, $0.16{\pm}0.01$, and $0.33{\pm}0.02$ at $30^{\circ}C$, $0.34{\pm}0.01$, $0.19{\pm}0.01$, and $0.35{\pm}0.02$ at $40^{\circ}C$ and $0.34{\pm}0.01$, $0.22{\pm}0.01$, and $0.38{\pm}0.02$ at $50^{\circ}C$ respectively. The result shows that Viscozyme was more effective than Pectinex at all experimental temperatures, and Viscozyme+Pectinex resulted in the highest phenolic content at $50^{\circ}C$. Antioxidant activities determined by DPPH, ABTS and FRAP assays were increased with concentrations of extracts produced by 2% of Viscozyme+Pectinex treatment, which ranged from 0.10 to 0.40 vit. C eq mM for $5{\sim}25\;mg$ of dried matters, from 0.09 to 0.28 vit. C eq mM for $1{\sim}5\;mg$ of dried matters, and from 0.06 to 1.85 $FeSO_4$ eq mM for $1{\sim}5\;mg$ of dried matters, respectively.