• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.738-744
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• 2008

In most developing countries consumers purchase retail cuts from hot carcasses and prepare traditional meat products as per their convenience and requirements. In this study, effects of different post mortem handling practices on quality of meat curry from culled sheep meat have been studied. After slaughter, leg cuts were subjected to nine commonly prevalent handling conditions in India viz. deboning (boning out) and cooking within 2-3 h (1), deboning immediately and cooking after 5-6 h (2), deboning after 5-6 h and cooking (3), deboning immediately, storage at $4^{\circ}C$ for 24 h and cooking (4), chilling for 24 h at $4^{\circ}C$, deboning and cooking (5), deboning after 5-6 h, storage for 24 h at $4^{\circ}C$, and cooking (6), deboning after 5-6 h, storage for 48 h at 4??C and cooking (7), deboning after 5-6 h, freezing and cooking (8), deboning after 5-6 h, storage for 24 h at $4^{\circ}C$, freezing and cooking (9). Significant differences were observed in pH, water-holding capacity, cooking loss and shear force values. Sensory scores were significantly higher in conditions (1), (5) and (9), and significantly lower in conditions (4) and (6). From the results, it was concluded that, to have the best quality product, meat should be cooked either immediately after slaughter or should be deboned just before cooking. Storage of deboned meat at refrigerated temperature must be avoided.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.120-126
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• 1989

Streptococcus diacetylactis and Leuconostoc cremoris were isolated from commercial culture and the effects of culture conditions on the diacetyl production by these strains and their mixture(1:1) were investigated. Optimum temperatures and culture times for the diacetyl production by Str. diacetylactis, Leu, cremoris and their mixture were 60hr at $22^{\circ}C$(diacetyl content, 2.24ppm), 48hr at $22^{\circ}C$(2.29ppm) and 48hr at $22^{\circ}C$ (2.21ppm), respectively Optimum initial pH for the diacetyl production by Str. diacetylactis, Leu. cremoris and the mixture were all 4.8(4.32, 6.66, 7.30ppm, respectively) and optimum sodium citrate concentrations(%, w/v) were 0.30(2.58ppm), 0.1(2.54ppm) and 0.1(2.52ppm), respectively. The diacetyl contents were gradually increased according as inoculation rates(%, w/v) were increased. The amounts of diacetyl produced under optimum conditions at 24hr incubation by Str. diacetylactis, Leu. cremoris and the mixture were 4.40, 6.59 and 7.25ppm, respectively. The most effective factor affecting diacetyl production under optimum condition was pH.

• Current Research on Agriculture and Life Sciences
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• v.16
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• pp.45-54
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• 1998

A thermotolerant bacterium, Streptomyces thermocyaneoviolaceus which produced xylan-degrading enzymes, utilized excellently xylan of wheat bran by producing the enzymes in comparison with that of birchwood or oat spelts. Optimal enzyme production was achieved in WB medium containing 0.8% wheat bran, 0.06% yeast extract, 0.06% bactopeptone, 0.05% $MgSO_4{\cdot}7H_2O$, 0.05% $FeSO_4{\cdot}7H_2O$, 0.05% $KH_2PO_4$ and, 0.2% $K_2HPO_4$(pH 7.0) at $50^{\circ}C$ for 24 hrs. The optimal pH and temperature for the hydrolysis of xylan were pH 5.5 and $65^{\circ}C$, respectively. The enzyme activity was retained more than 80% at the range from pH 4.5 to pH 9.5 at $4^{\circ}C$ for 12 hrs and 94% on the heat-treatment at $65^{\circ}C$ for 1 hr. Xylobiose, xylotriose, xylose, and other xylooligosaccharides were produced as end products from hydrolysis of birchwood xylan by the xylanase of S. thermocyaneoviolceus.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.1
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• pp.86-91
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• 2012

An in vitro rumen batch culture study was completed to compare effects of common grasses, leguminous shrubs and non-leguminous shrubs used for livestock grazing in Australia and Ghana on $CH_4$ production and fermentation characteristics. Grass species included Andropodon gayanus, Brachiaria ruziziensis and Pennisetum purpureum. Leguminous shrub species included Cajanus cajan, Cratylia argentea, Gliricidia sepium, Leucaena leucocephala and Stylosanthes guianensis and non-leguminous shrub species included Annona senegalensis, Moringa oleifera, Securinega virosa and Vitellaria paradoxa. Leaves were harvested, dried at $55^{\circ}C$ and ground through a 1 mm screen. Serum bottles containing 500 mg of forage, modified McDougall's buffer and rumen fluid were incubated under anaerobic conditions at $39^{\circ}C$ for 24 h. Samples of each forage type were removed after 0, 2, 6, 12 and 24 h of incubation for determination of cumulative gas production. Methane production, ammonia concentration and proportions of VFA were measured at 24 h. Concentration of aNDF (g/kg DM) ranged from 671 to 713 (grasses), 377 to 590 (leguminous shrubs) and 288 to 517 (non-leguminous shrubs). After 24 h of in vitro incubation, cumulative gas, $CH_4$ production, ammonia concentration, proportion of propionate in VFA and IVDMD differed (p<0.05) within each forage type. B. ruziziensis and G. sepium produced the highest cumulative gas, IVDMD, total VFA, proportion of propionate in VFA and the lowest A:P ratios within their forage types. Consequently, these two species produced moderate $CH_4$ emissions without compromising digestion. Grazing of these two species may be a strategy to reduce $CH_4$ emissions however further assessment in in vivo trials and at different stages of maturity is recommended.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.1002-1007
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• 2008

The purpose of this paper studied the optimal hydrogen production condition of plasma reforming system to operate the PEMFC. Plasma reforming reactor used with Ni catalyst reactor at the same time, So $H_2$ concentration increased. Also the WGS and PrOx reactor were designed to remove CO concentration under 10 ppm, because CO has effect on catalyst poisoning of PEMFC. The maximum $H_2$ production condition in plasma reforming system was S/C ratio 3.2, $CH_4$ flow rate 2.0 L/min, catalytic reactor temperature $700{\pm}5^{\circ}C$ and input power 900 W. At this time, the concentration of produced syngas was $H_2$ 70.2%, CO 7.5%, $CO_2$ 16.2%,$CH_4$ 1.8%. The hydrogen yield, hydrogen selectivity and $CH_4$ conversion rate were 56.8%, 38.1% and 92.2% respectively. The energy efficiency and specific energy requirement were 37.0%, 183.6 kJ/mol. In additional, The experiment of $CO_2/CH_4$ ratio proceeded. Also WGS reactor experiment was proceeding on optimum condition of plasma reactor and the exit concentration were $H_2$ 68%, CO 337 ppm, $CO_2$ 24.0%, $CH_4$ 2.2%, $C_2H_4$ 0.4%, $C_2H_6$ 4.1%. At this time, experiment result of PrOx reactor were $H_2$ 51.9%, CO 0%, $CO_2$ 17.3%.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.3
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• pp.197-205
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• 2013

An in vitro study was conducted to determine the effects of defaunation (removal of protozoa) and forage sources (rice straw, ryegrass and tall fescue) on ruminal fermentation characteristics, methane ($CH_4$) production and degradation by rumen microbes. Sodium lauryl sulfate, as a defaunation reagent, was added into the mixed culture solution to remove ruminal protozoa at a concentration of 0.375 mg/ml. Pure cellulose (0.64 g, Sigma, C8002) and three forage sources were incubated in the bottle of culture solution of mixed rumen microbes (faunation) or defaunation for up to 24 h. The concentration of ammonia-N was high under condition of defaunation compared to that from faunation in all incubations (p<0.001). Total VFA concentration was increased at 3, 6 and 12 h (p<0.05~p<0.01) but was decreased at 24 h incubation (p<0.001) under condition of defaunation. Defaunation decreased acetate (p<0.001) and butyrate (p<0.001) proportions at 6, 12 and 24 h incubation times, but increased propionate (p<0.001) proportion at all incubation times for forages. Effective degradability of dry matter was decreased by defaunation (p<0.001). Defaunation not only decreased total gas (p<0.001) and $CO_2$ (p<0.01~0.001) production at 12 and 24 h incubations, but reduced $CH_4$ production (p<0.001) at all incubation times for all forages. The $CH_4$ production, regardless of defaunation, in order of forage sources were rice straw > tall fescue > ryegrass > cellulose (p<0.001) up to 24 h incubation.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.4
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• pp.275-281
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• 2013

This study was conducted to increase the amount of bio-hydrogen production from microalgae(Chlorella vulgaris) in batch reactors by thermal pre-treatment. The optimization of thermal pre-treatment was conducted using statistic experimental design of response surface methodology. Two experimental parameters of temperature and reaction time were considered. The optimization condition was founded at the coded variables of <0.52, -0.07> corresponding to the experimental of heating temperature of $95.6^{\circ}C$ and reaction time of 57.9 min, respectively. Under the optimal condition, the maximum hydrogen production was predicted to 25.3mL $H_2/g$ dry cell weight (dcw), which was 9.1 times higher value of control(2.8mL $H_2/g$ dcw).

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.771-778
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• 1995

This study was carried out to produce the oligosaccharides(G2~G7) directly from the culture broth of Bacillus cereous IAM1072. The maximal production of oligosaccharides was obtained after cultivation at $30^{\circ}C$ for 24hrs in the mixture of 12% soluble starch, 1.5% peptone and 0.25% $K_2HPO_4$ adjusted to pH 7.0. Among the oligosaccharides produced $G_5$ oligosaccharide was purified. After methylation, the result of GC analysis was suggested to be oligosaccharide consisting of 5 glucose unit with ${\alpha}-1,4-glucosidic$ bond.

• Journal of Life Science
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• v.12 no.1
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• pp.43-48
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• 2002

An actinomycetes which produces fibrinolytic enzyme was isolated from soil. Characteristics of the isolated strain and the optimal conditions for the productions of fibrinolytic enzyme were summarized as follows; The fibrinolytic enzyme production strain generates gray airmycelium and had about 0.6~0.8$\times$0.4~0.8${\mu}{\textrm}{m}$ cylindrical spore, smooth surface and formed spore chain of 10~40 spores. We have identified this strain as Streptomyces sp. JK-20. This strain was able to grow up at 20~32$^{\circ}C$ and its optimum growth temperature and pH was 24$^{\circ}C$ and pH 6.0, respectively. The optimal conditions for porducing fibrinolytic enzyme; carbon source, nitrogen source, metal ions and phosphorous sources was 1% xylose, 0.5% yeast extract, 0.5% polypepton, 0.1% MgSO$_4$.7$H_2O$ and 0.1% NaH$_2$PO$_4$.2$H_2O$, respectively. This strain showed the highest productivity of fibrinolytic enzyme after the fourth day under such optimal culture conditions.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.327-329
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• 2023

In this study, an experiment was conducted to investigate the effect of the concentrations of tryptone, an organic nitrogen supplement, and sodium tungstate on the growth of microbial and the production of acetic acid and ethanol in the culture of Clostridium ljungdahlii. Microbial growth increased by 144.6%, and ethanol and acetic acid production improved by 8.6% and 36.7%, respectively, when 2.5 g/L of tryptone was added to the medium of the control experiment (0 g/L tryptone). In the experiment with 1 µM Na₂WO₄·2H₂O, which is 100 times higher than the condition of the medium used in the control experiment (0.01 µM Na₂WO₄·2H₂O), there was no significant difference in microbial growth or total production of C2 metabolites, but ethanol production increased and acetic acid production decreased. As a result, the ethanol/acetic acid production ratio increased significantly from 0.24 in the control experiment to 0.56.