51 research outputs found
The Galactic extinction and reddening from the South Galactic Cap U-band Sky Survey: u band galaxy number counts and color distribution
We study the integral Galactic extinction and reddening based on the galaxy
catalog of the South Galactic Cap U-band Sky Survey (SCUSS), where band
galaxy number counts and color distribution are used to derive the
Galactic extinction and reddening respectively. We compare these independent
statistical measurements with the reddening map of \citet{Schlegel1998}(SFD)
and find that both the extinction and reddening from the number counts and
color distribution are in good agreement with the SFD results at low extinction
regions ( mag). However, for high extinction regions
( mag), the SFD map overestimates the Galactic reddening
systematically, which can be approximated by a linear relation ]. By combing the results of galaxy number counts and
color distribution together, we find that the shape of the Galactic extinction
curve is in good agreement with the standard extinction law of
\cite{ODonnell1994}
Histamine production by Enterobacter aerogenes in chub mackerel (Scomber japonicus) at various storage temperatures
Extraction Optimization, Composition Analysis, and Antioxidation Evaluation of Polysaccharides from White Jelly Mushroom, Tremella fuciformis (Tremellomycetes)
Histamine production by Enterobacter aerogenes in chub mackerel (Scomber japonicus) at various storage temperatures
Abstract Growth of Enterobacter aerogenes and accumulation of histamine in chub mackerel (Scomber japonicus) were investigated through measuring bacterial count, histidine decarboxylase (HDC) activity and histamine content in fish samples stored at various temperatures from 4 to 37 °C. Results showed that bacterial count and HDC activity rapidly increased in chub mackerel inoculated with E. aerogenes at storage temperature above 20 °C and reached the highest values (8.64 log CFU/g and 31.68 U/g) at 37 °C. Meanwhile, fish samples stored at 25 and 37 °C for 18 h, formed histamine at above 50 mg/100 g of the potential hazard level. In contrast, bacterial growth and histamine formation were controlled for 36 h by cold storage at low temperature (4 °C). Therefore, strict temperature control was necessary for preservation and processing of chub mackerel in order to assure this marine fish safety
Histamine production by Enterobacter aerogenes in chub mackerel (Scomber japonicus) at various storage temperatures
Abstract Growth of Enterobacter aerogenes and accumulation of histamine in chub mackerel (Scomber japonicus) were investigated through measuring bacterial count, histidine decarboxylase (HDC) activity and histamine content in fish samples stored at various temperatures from 4 to 37 °C. Results showed that bacterial count and HDC activity rapidly increased in chub mackerel inoculated with E. aerogenes at storage temperature above 20 °C and reached the highest values (8.64 log CFU/g and 31.68 U/g) at 37 °C. Meanwhile, fish samples stored at 25 and 37 °C for 18 h, formed histamine at above 50 mg/100 g of the potential hazard level. In contrast, bacterial growth and histamine formation were controlled for 36 h by cold storage at low temperature (4 °C). Therefore, strict temperature control was necessary for preservation and processing of chub mackerel in order to assure this marine fish safety
Sonication enhances quality and antioxidant activity of blueberry juice
Abstract Effect of sonication on the blueberry juice was studied by evaluating the pH, viscosity, electric conductivity, color, total sugars, soluble solids, polyphenol, anthocyanidin, and radical scavenging activities. There were not any remarkable (p > 0.05) change in pH and electric conductivity. However, viscosity and color of blueberry juice markedly (p < 0.05) enhanced with the extension of sonication time. Meanwhile, total sugars, soluble solids, polyphenol, and anthocyanidin were obviously enhanced (p < 0.05). Moreover, prominent increase (p < 0.05) was observed on DPPH, superoxide, and hydroxyl radicals scavenging activities of sonicated blueberry juice. The current results exhibited sonication effectively improved blueberry juice quality and enhanced its antioxidant activity
Optimization of culture medium for production of melanin by Auricularia auricula
Abstract Melanin is a natural high molecular weight pigment with the huge application value and development potential in food industry. In the present study, medium composition for melanin production by fungus Auricularia auricula was investigated. Wheat bran extract, l-tyrosine, and CuSO4 were determined to optimize medium composition by response surface methodology with Box–Behnken design. Results indicated that the optimal medium composition was 26.80% (v/v) wheat bran extract, 1.59 g/L l-tyrosine, and 0.11 g/L CuSO4, and the maximum melanin yield was 519.54 mg/L. Melanin production through A. auricula fermentation avoided expensive enzymatic or complicated chemical methods for melanin extraction from tissues of plant or animal, which had the huge application value and development potential for efficient production of melanin
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