Microflora of heat-damaged rapeseed

1976 ◽  
Vol 54 (24) ◽  
pp. 2893-2902 ◽  
Author(s):  
J. T. Mills ◽  
G. J. Bollen
Keyword(s):  
Heat Resistance ◽  
Alternaria Alternata ◽  
Brassica Campestris ◽  
Fungal Flora ◽  
Surface Disinfection ◽  
Thermal Death ◽  
Storage Fungus ◽  
Thermal Death Point ◽  
Low Levels ◽  
Penicillium Spp

Microfloral components present on two sound lots (1 and 2) and three sample grade, heat-damaged lots (3 to 5) of stored Canadian rapeseed (Brassica campestris L. and B. napus L.) were determined with and without surface disinfection. Lots 1 and 2 were from a granary and a warehouse, respectively, and lots 3 to 5 were from primary elevators. Seed in lots 4, 5, and 3 showed progressively increased effects of heat damage as shown by the crush test. Sound lots 1 and 2 had mainly Alternaria and Cladosporium spp. with traces of Eurotium amstelodami, E. repens, and Penicillium spp. Lot 4 seed had low–medium levels of Alternaria alternata, Absidia ramosa, E. amstelodami, and Mucor pusillus. Lot 5 had high levels of E. amstelodami and low levels of Talaromyces thermophilus but A. alternata and M. pusillus were largely absent. Lot 3 had deeper-seated E. amstelodami, T. thermophilus, and Penicillium spp. than lots 4 and 5. Eurotium amstelodami was the predominant storage fungus in the heat-damaged lots. During the early stages of heating, E. amstelodami was often accompanied by the primary sugar fungi M. pusillus and A. ramosa, and after severe heating, by T. thermophilus. The thermal death point was between 50 and 60 °C for moist seed and between 80 and 90 °C for dry seed after 30-min exposure. With the exception of E. amstelodami, heat resistance of the fungal flora did not exceed that of the seed.

An investigation of the thermal death kinetics ofMycobacterium paratuberculosisduring pasteurisation

2000 ◽  
Vol 25 ◽  
pp. 71-76
Author(s):  
M.T. Rowe ◽  
I.R. Grant ◽  
H.J. Ball ◽  
C. Pope
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Heat Resistance ◽  
Raw Milk ◽  
Circumstantial Evidence ◽  
Infected Cattle ◽  
Thermal Death ◽  
Death Kinetics ◽  
Viability Stain ◽  
Thermal Death Kinetics

AbstractMycobacterium paratuberculosis is the known cause of Johne's disease in cattle and has been implicated as a cause of Crohn's disease in humans. Concern has been expressed that the organism, which is excreted in milk and faeces of infected cattle, may be transmitted via pasteurised milk. This is largely from work that has shown an unacceptable risk of survival of the organism when it is present in raw milk at numbers exceeding 102cfu/ml. Three possible reasons for this apparent heat resistance were investigated viz. use of a milk heating menstruum, presence of a heat resistant sub–population, and the tendency of the organism to form clumps. Heat resistance studies using a combined acid–fast/viability stain, and a comparison of the relative heat sensitivities of clumped and de-clumped M. paratuberculosis cells provided circumstantial evidence that it is the organism's tendency to form clumps which confers the apparent heat resistance. This work casts doubt on the efficacy of current commercial pasteurisation heat treatments (72°C/15s) for the inactivation of M. paratuberculosis. This would be of concern if a link between M. paratuberculosis and Crohn's disease is eventually established.

Thermal Death Point: I. Spores of Clostridium Tetani

1931 ◽  
Vol 48 (5) ◽  
pp. 436-456 ◽  
Author(s):  
T. J. Murray ◽  
M. R. Headlee
Keyword(s):  
Clostridium Tetani ◽  
Thermal Death ◽  
Thermal Death Point

Heat Resistance of Juice Spoilage Microorganisms

2002 ◽  
Vol 65 (8) ◽  
pp. 1271-1275 ◽  
Author(s):  
ADRIENNE E. H. SHEARER ◽  
ALEJANDRO S. MAZZOTTA ◽  
ROLENDA CHUYATE ◽  
DAVID E. GOMBAS
Keyword(s):  
Heat Resistance ◽  
Process Conditions ◽  
Citrate Buffer ◽  
Ph Values ◽  
Death Time ◽  
High Fructose ◽  
Thermal Death ◽  
Challenge Tests ◽  
D Values ◽  
Thermal Death Time

The heat resistance of various yeasts (Saccharomyces cerevisiae, Rhodotorula mucilaginosa, Torulaspora delbrueckii, and Zygosaccharomyces rouxii), molds (Penicillium citrinum, Penicillium roquefortii, and Aspergillus niger), and lactic acid bacteria (Lactobacillus fermentum and Lactobacillus plantarum) obtained from spoiled acid or acidified food products was determined in 0.1 M citrate buffer at pH values of 3.0, 3.5, and 4.0. S. cerevisiae was the most heat resistant of the microorganisms in citrate buffer, and its heat resistance was further evaluated in apple, grapefruit, calcium-fortified apple, and tomato juices as well as in a juice base with high fructose corn syrup. Decimal reduction times (D-values) and changes in temperature required to change the D-value (z-values) for S. cerevisiae were higher in the juices than in citrate buffer at all pH values tested. The D57°C(135°F)-values varied from 9.4 min in the juice product with pH 2.8 to 32 min in a calcium-added apple juice with pH 3.9. The S. cerevisiae strain used in this study can be used in thermal-death-time experiments in acidic products to calculate process conditions and in challenge tests to validate the calculated temperatures and hold times during processing.

Mycoflora associated with diseased rice grains in Bangladesh and their pathogenic potentiality

2021 ◽  
Vol 7 (1) ◽  
pp. 932-940
Author(s):  
Pranami Chowdhury ◽  
Shamim Shamsi ◽  
Hasna Hena Begum ◽  
Md Abul Bashar
Keyword(s):  
Alternaria Alternata ◽  
Fusarium Moniliforme ◽  
Trichoderma Viride ◽  
Curvularia Lunata ◽  
Rice Grain ◽  
Aspergillus Clavatus ◽  
Cultivated Rice ◽  
Rice Varieties ◽  
Rice Samples ◽  
Penicillium Spp

Fifty six spotted rice grain samples of four commercially cultivated rice varieties namely BRRI 28, 29, Kalijira and Pajam were collected from 14 different districts of Bangladesh. Forty rice samples (Hybrid 2,3,4, BR7,11,12,14,16,22,23,25,26and BRRI28 to BRRI 55) were also collected from Bangladesh Rice Research Institute at Joydevpur. Twenty-fivespecies of fungi belonging to 15 genera were associated with these rice varieties. The isolated fungi were Alternaria alternata, Aspergillus clavatus, A. flavus, A. fumigatus, A.niger, A. ochraceus, A.oryzae, A. terreus, Chaetomium globosum, Cladosporium cladosporioides, Colletotrichum gloeosporioides, Curvularia lunata, C. lunata var. aeria, Drechslera oryzae, Fusarium moniliforme, F. oxysporum, F. solani, Microdochium oryzae, Nigrospora oryzae, Penicillium spp., Pestalotiopsis guepinii, Sarocladium oryzae and Trichoderma viride. Amongst these fungi nine i.e. Alternaria alternata (Fr.) Keissler, Aspergillus flavus Link, Curvularia lunata (Wakker) Boedijn, Drechsler aoryzae Breda de Haan (Subramanian and Jain), Fusarium moniliforme Sheldon, F. solani (Mart.) Sacc., Microdochium oryzae (Hashloka and Yokogi) Sam. and Hal., Pestalotiopsis guepinii (Desm.) Stay. and Sarocladium oryzae (Sawada) W. Gams and D. Hawks were found to be pathogenic to rice seeds. The most predominant fungus was D. oryzae which was followed by A. flavus and the least incidence was observed in case of F. solani and P. guepinni. Bioresearch Commu. 7(1): 932-940, 2021 (January)

scholarly journals Fungal Decay of First-Crop and Main-Crop Figs

Plant Disease ◽  
2007 ◽  
Vol 91 (12) ◽  
pp. 1657-1662 ◽  
Author(s):  
Mark A. Doster ◽  
Themis J. Michailides
Keyword(s):  
Aspergillus Niger ◽  
Alternaria Alternata ◽  
Late Summer ◽  
Early Summer ◽  
Late Spring ◽  
Fungal Decay ◽  
Main Crop ◽  
Low Levels ◽  
Serious Disease

Fig cultivars grown in California typically have two crops, although the first crop may be unimportant commercially. The first crop, also known as the breba crop, ripens in late spring and early summer, whereas the main or second crop ripens in late summer. For both cultivars studied, Conadria and Calimyrna, the first-crop figs typically are left in the orchard unharvested. First-crop figs had relatively high levels of fungal decay and tended to have more fungal decay than main-crop figs, especially Alternaria rot (caused by Alternaria alternata and Ulocladium atrum). At least 16 different Aspergillus spp. were found decaying first-crop figs. Fig smut, a serious disease caused by Aspergillus niger and related fungi, usually was present at approximately the same level in first-crop and main-crop figs. Aspergillus spp. known to produce the mycotoxins aflatoxin or ochratoxin were found decaying first-crop figs. Aflatoxin was detected in first-crop figs at low levels similar to those detected in the main-crop figs. Because the abundant spores produced on the first-crop figs can infect main-crop figs, the fungal decay of first-crop figs might result in higher levels of decay for main-crop figs.

scholarly journals THE THERMAL DEATH-POINT OF TUBERCLE BACILLI IN MILK AND SOME OTHER FLUIDS

1899 ◽  
Vol 4 (2) ◽  
pp. 217-233 ◽  
Author(s):  
Theobald Smith
Keyword(s):  
Salt Solution ◽  
Distilled Water ◽  
Thermal Death ◽  
Thermal Death Point

1. Tubercle bacilli when suspended in. distilled water, normal salt solution, bouillon and milk, are destroyed at 60° C. in 15 to 20 minutes. The larger number are destroyed in 5 to 10 minutes. 2. When tubercle bacilli are suspended in milk, the pellicle which forms during the exposure at 60° C. may contain living bacilli after 60 minutes.

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