• Korean Journal of Poultry Science
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• v.26 no.1
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• pp.1-25
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• 1999

Concerns about meat quality, including chicken meat, for the human diet has led to many attempts to manipulate the carcass fat and increase the eating quality. For actual eating quality, the birds must be grown and finished in a manner that results in meat that are tender, succulent and of good flavor, as well as being free from any foreign taint, flavor or safety hazard. Tenderization treatment with high voltage(820V) electrical stimulation and prechill muscle tensioning would improve the tenderness of chicken meat. Proper programs for the withdrawal of feed and water require a team approach for maximizing yield of meat and minimizing carcass contamination. Also effding of supplemental levels of-tocopherol to poultry with vegetable or fish oils increases of desirable polyunsaturated fatty acid(PUFA) content and stablizes the meat against rancidity and fish off-flavors. The nutritional effects of varying dietary ingredients on broiler carcass fat content are also important. Increasing the levels of energy in the ration increases the carcass fat content, while increasing the proteing levels decreases carcass fat content. Supplement-tation of poultry diets with amino acids such as methionine, lysine, glycine and tryptophan as well as amino acid such as well as amino acid mixtures can reduce body fat deposition. Normal stress leads to chicken muscular damage resulting in reduced meat quality, but this can be controlled by preslaughter management practices. Feed manufactures can utilize ntilize nutrient modulation to control pale soft exudative(PSE)syndrome. Finally, the success in poultry meat production depends on the consistent achievement of carefully selected levels of quality. Quality assurance should be the wider function of incorporating quality into the production system and the combination of motivating quality into actions and operations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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• pp.154-162
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• 2006

Cheese analogs using lipoxygenase-defected soymilk and ${\alpha}$-chymotrypsin modified soy protein isolate (SPI) were prepared. Color, textural properties, sensory attributes and melting spreadability of cheese analogs were evaluated and compared with mozzarella cheese, and relationships between textural properties, sensory attributes and melting spreadability of cheese analogs were analyzed. Off-flavors were not mostly discriminated. Cheese analogs containing 10% SPI untreated and containing 6% and 8% SPI treated by ${\alpha}$-chymotrypsin in ${\Delta}E$ value of color were the most similar to mozzarella cheese. Quality characteristics and melting spreadability of cheese analogs were highly affected and improved by ${\alpha}$-chymotrypsin modification. Sensory attributes and melting spreadability of cheese analogs containing 6% SPI treated by ${\alpha}$-chymotrypsin were the most similar to mozzarella cheese, while in textural properties, cheese analogs containing 10% SPI were the most similar with mozzarella cheese. Hardness in sensory attributes was highly positively correlated with hardness (r>0.65), adhesiveness (r>0.56), chewiness (r>0.77) and gumminess (r>0.76) in textural properties, while it was highly negatively correlated with melting spreadability (r>-0.68).

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.808-812
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• 1998

Melania snail(Semisulcopira bensoni) is used as ingredient in Korean traditional soup and nutritional foods. Generally, lipoxygenase in several food products may produce off-flavors during their processing and storage. Therefore, the inactivation of lipoxygenase is required to make the better extracts from Melania sanil. Also, the quality on freshness of Melania snail may be evaluated by lipoxygenase activity. The lipoxygenae activity was the highest at 40~60% saturation among several concentrations in salting-ouot saturated solution of ammonium sulfate. The partial purification of lipoxygenase was successfully obtained by Sephacryl S-200 gel chromatography. The first peak among three peaks for protein determination showed the highest activity of lipoxygenase in 13~16 fractions among 100 fractions. The highest peak of lipoxygenase activity by ion exchange chromatography was shown at 0.1M NaCl. In the purification step, the specific activity was 20.8U/mg and activity yield was 19.8%. The optimum pH and temperature were pH6.0~8.0 and 3$0^{\circ}C$, respectively. Molecular weight of the lipoxygenase was estimated about 35kDa by SDS-PAGE.

• KSBB Journal
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• v.15 no.5
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• pp.438-443
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• 2000

Continuous processes using immobilized yeast were investigated in order to shorten beer maturation time. Three silica-based ceramic media and one cellulose-based medium were used. Diacetyl (DA) was one of the most distinctive compounds causing immature flavors. Heat treatment of green beer (GB) to convert a-acetolactate to DA was essential to shorten the time for beer maturation. The longer heat treatment time was needed at the lower temperature. Oxygen concentration in GB had a large influence on the conversion of a-acetolactate to DA. The lower the oxygen concentration in GB, the lower conversion ratio to DA. Heat treated GB was fed continuously to four kinds of immobilized yeast columns. DA concentration after immobilization columns was reduced to less than 0.1ppm at $3∼5^{\circ}C$ 180∼150 minutes retention time in all columns tested. This concentration is enough to fit the quality speification of commercialized product. Formation of a-acetolactate from residual sugars was higher in ceramic media column than cellulose media cloumn. The taste of beers from test processes were not the same as that of traditionally produced beer, but no off-flavors were detected in test samples, which shows that immobilized yeast columns have potentials as rapid processes for beer maturation.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.19-24
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• 1995

The effect of several inhibitors such as ascorbic acid on the lipoxygenase in soybeans known to catalyze reaction resulting in racid off-flavors was examined in the soybean homogenates by the oxygen electrode method. Among 8 compounds added at homogenizing process, 10 mM ascorbic acid inhibited lipoxygenase-1 and lipoxygenase-2/3 activities to 41.7 and 49.8%, respectively. Inactivation of lipoxygenase-2/3 was highly accelerated by homogenization for 15 min at room temperature, so the activity was inhibited 70.8% comparing with the homogenization of 3 min. When soybean homogenates with 10 mM ascorbic acid was stored at $25^{\circ}C$ for 72 hrs, lipoxygenase-2/3 activities lowered to 52.8% whereas L-1 activities lowered to 15.8%. Since it is reported that lipoxygenase-2 is responsible for the off-flavor of soybean products, the inhibitory effect of ascorbic acid among several inhibitors investigated might be useful in soybean processing.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.509-514
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• 2009

The effectiveness of a technique for binding rice-washed solution with trimethylamine (TMA) was investigated in this study. The mixtures of TMA and rice-washed solution were quantified using an electronic nose based on the mass spectrometer. After 7 min of reaction in a model system, the binding of TMA to the rice-washed solution was detected. As the concentration of rice-washed solution increased, the levels of TMA detected in the headspace decreased, thereby indicating an increase in the binding of TMA to the rice-washed solution. The binding effect of the rice-washed solution was comparable to those of starch, ${\alpha}$-cyclodextrin, or amylose, and superior to that of flour. The results of this study demonstrate the potential for reduction of off-flavors using the rice-washed solution.

• Preventive Nutrition and Food Science
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• v.18 no.1
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• pp.67-75
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• 2013

Descriptive analysis and consumer acceptance tests were conducted with frozen (FCR), homemade (HCR), and aseptic-packaged (ACR) cooked rice products from two cultivars-IM and SD. FCR was prepared using a rapid freezing process, which may provide consumers with a quality similar to that of HCR. The intensity of the flavors of roasted, glutinous rice, rice cake, and rice starch and the textures of glutinousness, moistness, chunkiness, adhesiveness, and squishiness were all greater in the FCR as compared to the HCR and ACR (p<0.05) in IM and SD cultivars. The differences in sensory characteristics between the FCR and ACR were larger than the equivalent differences between the FCR and HCR. Overall consumer acceptance ratings for FCR in overall aspect, appearance, aroma, and texture were not significantly different compared to those for HCR (p>0.05); however, in most cases these factors showed significant differences when compared with ACR (p<0.05). From partial least square regression analysis, cooked rice was positively related to sweet, transparency, glossiness, roasted, glutinousness, chunkiness, moistness, glutinous rice, adhesiveness, rice shape, rice starch, and squishiness attributes but negatively related to raw rice, old rice, old rice aroma, a particle feeling, off-aroma, white color, scatteredness, slickness, size of cooked rice, and firmness attributes.

• Food Science of Animal Resources
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• v.34 no.4
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• pp.543-551
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• 2014

The aim of this study was to evaluate the effect of proteolytic (Serratia liquefaciens, match %: 99.39) or lipolytic (Acinetobacter genomospecies 10, match %: 99.90) psychrotrophic bacteria (bacterial counts, analysis of free fatty acids (FFA) and analysis of free amino acids) on the microbial and chemical properties (yogurt composition), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of yogurt during storage. Yogurts were prepared with raw milk preinoculated with each psychrotrophic bacteria. The total solid, fat, and protein content were not affected by preinoculation, but the pH of yogurt preinoculated with psychrotrophic bacteria was higher than in control. There was a dramatic increase in short chain free fatty acids among FFA in yogurt with Acinetobacter genomospecies 10. For 14 d of cold storage condition, SCFFA was 25.3 mg/kg to 34.4 mg/kg (1.36 times increased), MCFFA was 20.4 mg/kg to 25.7 mg/kg (1.26 times increased), and LCFFA was 240.2 mg/kg to 322.8 mg/kg (1.34 times increased). Serratia liquefaciens (match %: 99.39) in yogurt caused a greater accumulation of free amino acids (FAA), especially bitter peptides such as leucine, valine, arginine, and tyrosine, but SDS-PAGE showed that the inoculation of Serratia liquefaciens did not affect the degree of casein degradation during storage. Taken together, the excessive peptides and FFA in yogurt generated from psychrotrophic bacteria could develop off-flavors that degrade the quality of commercial yogurt products.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.553-560
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• 2012

This study was conducted to compare the physicochemical and sensory properties of yogurt containing nanopowdered peanut sprouts (NPPS) and powdered peanut sprouts (PPS) at different concentrations (0.05-0.20%, w/v) during storage at $4^{\circ}C$ for 16 d. The pH values of NPPS (0.05-0.20%, w/v)-added yogurt were lower than those of PPS-added yogurt. The antiradical scavenging activity and LAB counts were significantly higher in NPPS-added yogurt than in PPS-added yogurt during the storage period of 16 d (p<0.05). Higher concentrations (0.15, and 0.20%) NPPS-added yogurt showed greater antiradical scavenging activity. The LAB counts were ranged from $9.00{\times}10^8$ to $1.10{\times}10^9$ and $1.30{\times}10^9$ to $9.10{\times}10^8$ CFU/mL in 0.05% and 0.20% NPPS-added yogurts, respectively. In sensory testing, 0.05 and 0.10% NPPS-added yogurt showed similar results to the control in whey-off, grainy texture, and overall acceptability. Yellowness and astringent scores increased with increasing addition of NPPS or PPS to the yogurt irrespective of its storage times. Peanut and beany flavors were lower during the storage for 0.05 and 0.10% NPPS-added yogurt. Based on the data obtained from the present study, it was concluded that 0.05 and 0.10%, w/v of NPPS could be used to produce NPPS-added yogurt without significant adverse effects on the physicochemical and sensory properties, but with an enhanced functional value added to the yogurt.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1132-1137
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• 2009

Successive application of Saccharomyces cerevisiae DSM 70424 and Saccharomyces rouxii DSM 2535 or DSM 2531 in the production of non-alcoholic beer was investigated. The aim of the study was to consider the impact of the 2 mentioned strains of S. rouxii on the reduction of alcohol content in wort fermented at 12 or $24^{\circ}C$ for 96 hr, applying periodic aeration. The 2 S. rouxii strains were added at the $48^{th}$ hr of fermentation after thermal inactivation of S. cerevisiae cells. The greatest alcohol decrease rate was observed for the treatment containing S. rouxii DSM 2535-fermented at $24^{\circ}C$ (from 1.56 to 0.36%). The concentration of acetaldehyde, diacetyl, and 2,3-pentandione, that have a key role in appearance of 'wort' and 'buttery' off flavors, were significantly lower in S. rouxii-containing treatments fermented at $24^{\circ}C$. S. rouxii-containing treatment fermented at $24^{\circ}C$ showed slightly lower overall flavor acceptability compared to S. cerevisiae-containing treatment fermented at the same temperature. Such score was improved for the products obtained at $12^{\circ}C$.