Effect of gamma irradiation and heat treatment on the artificial contamination of maize grains by Aspergillus flavus Link NRRL 5906

2017 ◽  
Vol 71 ◽  
pp. 57-63 ◽  
Author(s):  
Mohamed Albuzaudi ◽  
Tero Eerikäinen ◽  
Ossi Turunen ◽  
Mohamed Ghelawi ◽  
M. El Haj Assad ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Gamma Irradiation ◽  
Aspergillus Flavus

Influence of Temperature and Water Activity on Aflatoxin Production by Aspergillus flavus in Cowpea (Vigna unguiculata) Seeds and Meal

1985 ◽  
Vol 48 (12) ◽  
pp. 1040-1043 ◽  
Author(s):  
P. E. KOEHLER ◽  
L. R. BEUCHAT ◽  
M. S. CHHINNAN
Keyword(s):  
Heat Treatment ◽  
Water Activity ◽  
Aspergillus Flavus ◽  
Vigna Unguiculata ◽  
Dry Weight ◽  
Aflatoxin Production ◽  
Weight Basis ◽  
Influence Of Temperature

Experiments were done to determine the influence of temperature (21, 30 and 37°C) and aw (0.76 to 0.98) on aflatoxin production by Aspergillus flavus on cowpea (Vigna unguiculata) seeds, meal and meal supplemented with onion. Larger quantities of aflatoxin were produced at 21 and 30°C than at 37°C. The highest amount of aflatoxin (2777 μg/20 g, dry weight basis) was observed in meal containing onion at aw 0.98 after 20 d of incubation at 21°C. A level of 870 |μg/20 g was detected in seeds at aw 0.95 after 14 d of incubation at 30°C. Meal at aw 0.96 supported production of 551 μg of aflatoxin per 20 g after 20 d at 30° C. Temperature had little influence on the optimal aw for aflatoxin production in cowpea meal. However, an increase in temperature resulted in a decreased optimal aw for aflatoxin production on whole cowpeas. When known quantities of aflatoxin were added to cowpea meal which was subsequently steamed for 5 min, only 29% was extractable using a variety of procedures, indicating that the toxin may be bound in some manner to cowpea constituents as a result of heat treatment.

Mössbauer effect study of the effect of gamma irradiation and heat treatment on montmorillonite

1994 ◽  
Vol 91 (1) ◽  
pp. 783-787 ◽  
Author(s):  
N. A. Eissa ◽  
N. H. Sheta ◽  
W. M. El Meligy ◽  
H. A. Sallam
Keyword(s):  
Heat Treatment ◽  
Gamma Irradiation ◽  
Mössbauer Effect ◽  
Effect Study ◽  
Mossbauer Effect

Effects of physical preservation methods on sclerotial germination in Aspergillus flavus and Aspergillus ochraceus in stored grain

1992 ◽  
Vol 70 (6) ◽  
pp. 1206-1210 ◽  
Author(s):  
M. Menasherov ◽  
N. Paster ◽  
R. Nitzan
Keyword(s):  
Gamma Irradiation ◽  
Aspergillus Flavus ◽  
Combined Treatment ◽  
Aspergillus Ochraceus ◽  
Combined Treatments ◽  
Stored Grain ◽  
Modified Atmospheres ◽  
Irradiation Dosage ◽  
Different Levels ◽  
Sclerotial Germination

Germination of sclerotia of Aspergillus flavus and Aspergillus ochraceus was assessed following gamma irradiation during exposure to different levels of relative humidities or to various modified atmospheres. The effect of combined treatments on germination was also studied. No sclerotia of either fungi germinated following irradiation with 2.5 kGy. At 80% relative humidity, germination was almost completely inhibited during 50 days of exposure. Sclerotia of A. flavus were found to tolerate higher levels of CO2 than those of A. ochraceus, and 100% germination of the former, but not the latter, occurred at 80% CO2 (given with either 20 or 5% O2). Germination of A. flavus sclerotia was markedly reduced only at modified atmospheres of 40% CO2 and 1% O2. Working with two sublethal dosages of gamma irradiation, 1.0 and 1.5 kGy, it was demonstrated that less CO2 was needed in the atmosphere (with 20% O2) to reduce germination as the irradiation dosage increased. The advantages of the combined treatment compared with each treatment applied alone are discussed. Key words: sclerotia, germination, Aspergillus, inhibition, physical methods.

Structural evolution of defective graphene under heat treatment and gamma irradiation

2018 ◽  
Vol 97 ◽  
pp. 151-154 ◽  
Author(s):  
Yifei Zhang ◽  
Jie Shi ◽  
Cheng Chen ◽  
Nan Li ◽  
Zhiwei Xu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Gamma Irradiation ◽  
Structural Evolution ◽  
Defective Graphene

Effect of Moist Heat Treatment on Sensory Qualities of Peanut Kernels

1979 ◽  
Vol 6 (2) ◽  
pp. 93-95
Author(s):  
L. R. Beuchat ◽  
P. E. Koehler
Keyword(s):  
Heat Treatment ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Aspergillus Flavus ◽  
Sensory Panel ◽  
Moist Heat ◽  
Organoleptic Characteristics ◽  
Sensory Qualities ◽  
And Control ◽  
Control Samples

Abstract Shelled Florunner cv. peanut kernels adjusted to 12 to 13% moisture were subjected to heat treatments at 60, 90, and 120° C for periods of 1 and 2 hr. Kernels were then dried, oil-roasted, and examined for sensory qualities. Moistened, heated kernels were also inoculated with an aflatoxigenic strain of Aspergillus flavus and analyzed for free fatty acid (FFA) and aflatoxin contents at weekly intervals over a 6-week period of incubation at 30°C. Treatment of moist kernels at 60°C for 1 or 2 hr caused the FFA content to increase from 1.2% (unheated) to 2.2%, whereas treatment at 90 and 120°C for the same periods of time resulted in FFA contents ranging from 10.3 to 13.2%. After 6 weeks, the FFA content of all inoculated and control samples ranged from 11.5 to 14.5%. Sensory panel evaluations of uninoculated, roasted kernels indicated that moist heat treatment at 60°C did not significantly (P ≤ 0.05) alter organoleptic characteristics; treatment at 90°C for 2 hr resulted in significantly lower scores for texture and flavor, whereas treatment at 120°C resulted in a general decrease in all sensory qualities. Kernels heated prior to inoculation with A. flavus did not appear to support growth as well as did unheated kernels early in the 6-week test period.

Conclusive comparison of gamma irradiation and heat treatment for color enhancement of Rubellite from Mozambique

2019 ◽  
Vol 103 ◽  
pp. 102926
Author(s):  
Bongkot Phichaikamjornwut ◽  
Sorapong Pongkrapan ◽  
Saweat Intarasiri ◽  
Duangkhae Bootkul
Keyword(s):  
Heat Treatment ◽  
Gamma Irradiation ◽  
Color Enhancement
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