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George Gettinby - One of the best experts on this subject based on the ideXlab platform.
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Effects of Temperature, Water Activity, and Incubation Time on Production of Aflatoxins and Cyclopiazonic Acid by an Isolate of Aspergillus flavus in Surface Agar Culture
Applied and environmental microbiology, 1997Co-Authors: N. Gqaleni, John E. Smith, John Lacey, George GettinbyAbstract:An experiment with a full factorial design was used to study the effects of and interactions among temperature, water activity (a(infw)), incubation period, and substrate on coproduction of aflatoxins (AF) and cyclopiazonic acid (CPA) by an isolate of Aspergillus flavus. Analysis of variance showed that there was a complex interaction among all of these factors and that this influenced the relative concentrations of the mycotoxins produced. The optimum temperatures for the production of AF and CPA were 30(deg)C and 25(deg)C, respectively. Both mycotoxins were maximally produced (0.306 to 0.330 (mu)g of AF(middot)ml of medium(sup-1), 4.040 to 6.256 (mu)g of CPA(middot)ml of medium(sup-1)) at an a(infw) of 0.996 and after 15 days of incubation. No AF were produced in either Yeast extract agar or Czapek Yeast Autolysate agar medium at an a(infw) of 0.90 at 20 or 37(deg)C after 15 days (minimum conditions), while 0.077 to 0.439 (mu)g of CPA(middot)ml of medium(sup-1) was produced under the same conditions. Yeast extract agar favored maximum AF production, and Czapek Yeast Autolysate agar favored maximum CPA production.
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Production of the mycotoxin cyclopiazonic acid by Penicillium commune on solid agar media: Effects of water activity, temperature, and incubation time
Journal of food protection, 1996Co-Authors: N. Gqaleni, John E. Smith, John Lacey, George GettinbyAbstract:The combined effects of water activity (aw), temperature, incubation time, and medium composition on cyclopiazonic acid (CPA) production by an isolate of Penicillium commune was studied using a full-factorial experimental design. An analysis of variance for the mycotoxin showed that there was a complex interaction between all these factors and that this affected the production of CPA. The minimum aw for CPA production (0.025 to 0.238 μg ml-1) in Yeast extract agar was 0.90 whereas in Czapek Yeast Autolysate agar it was 0.85 (0.048 to 0.123 μg m1-1). The temperature range for CPA production was 20 to 30°C. The optimum temperature for CPA production was 25°C. CPA was maximally produced (3.199 to 3.993 μg ml-1) at an aw of 0.996 after 15 days of incubation.
Milan Maksimovic - One of the best experts on this subject based on the ideXlab platform.
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contribution of lactic acid fermentation to improved nutritive quality vegetable juices enriched with brewer s Yeast Autolysate
Food Chemistry, 2007Co-Authors: Marica Rakin, Maja Vukasinovic, Slavica Silermarinkovic, Milan MaksimovicAbstract:Abstract Vegetables are rich sources of the biologically active compounds which have beneficial effects in prevention of some diseases and certain types of cancer. From the point of view of protection and health, the objective of this paper was to optimize food content in order to obtain a functional food. In order to improve the nutritive and protective properties of the product, the beetroot and carrot juices enriched with brewer’s Yeast Autolysate were subjected to lactic-acid fermentation with Lactobacillus acidophilus NCDO1748. Chemical compositions of produced fermented bioproducts showed that fermented carrot juice with brewer’s Yeast Autolysate had higher contents of some minerals (Ca, P, Fe) and β-carotene than had beetroot juice with brewer’s Yeast Autolysate. Higher mineral content in the carrot juice better affected production of lactic acid in that sample. Fermented beetroot juice with brewer’s Yeast Autolysate had higher contents of betanin and vitamin C, which were in accordance with the contents of these components in raw beetroot that did not significantly vary during the processing of the material (pasteurization, fermentation). Thus the fermented bioproduct 3, which is a mixture of beetroot and carrot juices with brewer’s Yeast Autolysate, represents the product with optimum proportions of pigments, vitamins and minerals.
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The examination of parameters for lactic acid fermentation and nutritive value of fermented juice of beetroot, carrot and brewers Yeast Autolysate
Serbian Chemical Society, 2004Co-Authors: Milan Maksimovic, Maja Vukasinovic, Josip Baras, Marica RakinAbstract:The conditions for lactic acid fermentation based on a mixture of beetoot juice (Beta vulgaris L.) and carrot juice (Daucus carota L.) and different content of brewers Yeast Autolysate with Lactobacillus plantarum A112 and with Lactobacillus acidophilus NCDO 1748 has been studied. Both cultures showed good biochemical activity in these mixtures. The production of lactic acid has been stimulated using a higher content of brewers Yeast Autolysate. In these mixtures, L. plantarum A112 showed better growth and lactic acid production than L. acidophilus NCDO 1748. From the data obtained through chemical analyses of the fermented products, it can be seen that the mixture of beetroot and carrot juice and brewers Yeast Autolysate is richer in minerals (Ca, P, Fe) and b-carotene than fermented beetroot juice with the same content of brewers Yeast Autolysate
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the examination of parameters for lactic acid fermentation and nutritive value of fermented juice of beetroot carrot and brewer s Yeast Autolysate
Journal of The Serbian Chemical Society, 2004Co-Authors: Marica Rakin, Josip Baras, Maja Vukasinovic, Milan MaksimovicAbstract:Abstract : The conditions for lactic acid fermentation based on a mixture of beetootjuice ( Beta vulgaris L.) and carrot juice ( Daucus carota L.) and different content ofbrewer’s Yeast Autolysate with Lactobacillus plantarum A112 and with Lacto-bacillus acidophilus NCDO 1748 has been studied. Both cultures showed good bio-chemical activity in these mixtures. The production of lactic acid has been stimu-lated using a higher content of brewer’s Yeast Autolysate. In these mixtures, L.plantarum A112 showed better growth and lactic acid production than L. acido-philus NCDO 1748. From the data obtained through chemical analyses of thefermented products, it can be seen that the mixture of beetroot and carrot juice andbrewer’s Yeast Autolysate is richer in minerals (Ca, P, Fe) and -carotene than fer-mented beetroot juice with the same content of brewer’s Yeast Autolysate. Keywords : beetroot, carrot, lactic acid fermentation, Autolysate of brewer’s Yeast,nutrition.INTRODUCTION During the closing decades of the 20
N. Gqaleni - One of the best experts on this subject based on the ideXlab platform.
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Effects of Temperature, Water Activity, and Incubation Time on Production of Aflatoxins and Cyclopiazonic Acid by an Isolate of Aspergillus flavus in Surface Agar Culture
Applied and environmental microbiology, 1997Co-Authors: N. Gqaleni, John E. Smith, John Lacey, George GettinbyAbstract:An experiment with a full factorial design was used to study the effects of and interactions among temperature, water activity (a(infw)), incubation period, and substrate on coproduction of aflatoxins (AF) and cyclopiazonic acid (CPA) by an isolate of Aspergillus flavus. Analysis of variance showed that there was a complex interaction among all of these factors and that this influenced the relative concentrations of the mycotoxins produced. The optimum temperatures for the production of AF and CPA were 30(deg)C and 25(deg)C, respectively. Both mycotoxins were maximally produced (0.306 to 0.330 (mu)g of AF(middot)ml of medium(sup-1), 4.040 to 6.256 (mu)g of CPA(middot)ml of medium(sup-1)) at an a(infw) of 0.996 and after 15 days of incubation. No AF were produced in either Yeast extract agar or Czapek Yeast Autolysate agar medium at an a(infw) of 0.90 at 20 or 37(deg)C after 15 days (minimum conditions), while 0.077 to 0.439 (mu)g of CPA(middot)ml of medium(sup-1) was produced under the same conditions. Yeast extract agar favored maximum AF production, and Czapek Yeast Autolysate agar favored maximum CPA production.
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Production of the mycotoxin cyclopiazonic acid by Penicillium commune on solid agar media: Effects of water activity, temperature, and incubation time
Journal of food protection, 1996Co-Authors: N. Gqaleni, John E. Smith, John Lacey, George GettinbyAbstract:The combined effects of water activity (aw), temperature, incubation time, and medium composition on cyclopiazonic acid (CPA) production by an isolate of Penicillium commune was studied using a full-factorial experimental design. An analysis of variance for the mycotoxin showed that there was a complex interaction between all these factors and that this affected the production of CPA. The minimum aw for CPA production (0.025 to 0.238 μg ml-1) in Yeast extract agar was 0.90 whereas in Czapek Yeast Autolysate agar it was 0.85 (0.048 to 0.123 μg m1-1). The temperature range for CPA production was 20 to 30°C. The optimum temperature for CPA production was 25°C. CPA was maximally produced (3.199 to 3.993 μg ml-1) at an aw of 0.996 after 15 days of incubation.
Piergiorgio Comuzzo - One of the best experts on this subject based on the ideXlab platform.
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Effect of a Yeast Autolysate produced by high pressure homogenization on white wine evolution during ageing
Journal of Food Science and Technology, 2020Co-Authors: Sabrina Voce, Sonia Calligaris, Piergiorgio ComuzzoAbstract:The enological characteristics and the performances of a Yeast Autolysate produced by high pressure homogenization (HPH-YD) were investigated for the first time in white wine and model solution, in comparison with a thermolysate (T-YD) and a commercial Yeast derivative (COMM). In wine-like medium, HPH-YD showed a significant release of glucidic colloids (on average, slightly higher than the other products), also leading to a greater glutathione solubilization with respect to T-YD. Concerning the volatile composition of the Autolysates, HPH-YD was characterized by the highest concentration of alcohols and esters, while showing an average amount of fatty acids, carbonyls and heterocyclic compounds lower than COMM. These features are potentially linked to a more favorable impact of this product on the composition of wine aroma, should these compounds be released into the wine itself. HPH-YD determined minor modifications on wine volatile profile when added for short contact times, without releasing unwanted compounds and with a slightly lower binding capacity towards wine esters. The effects of the three Yeast derivatives (YDs) on wine color during ageing was also investigated in comparison with sulfur dioxide (SO_2). HPH-YD was the most efficient preparation, limiting wine color changes due to oxidation during four months and behaving more similarly to SO_2. The use of HPH for the production of Yeast Autolysates for winemaking may represent an interesting alternative to thermal treatments, improving the enological characteristics of these additives, particularly their antioxidant capacity, leading anyhow a significant release of colloidal molecules and a limited impact on wine aroma composition.
A Meats - One of the best experts on this subject based on the ideXlab platform.
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Bacteria as food had no effect on fecundity during domestication of the fruit fly, Bactrocera tryoni
Journal of Applied Entomology, 2009Co-Authors: A Meats, K. Streamer, A S GilchristAbstract:Adult Bactrocera tryoni from different generations of domestication were given various diets to determine whether either or both the bacteria Klebsiella oxytoca and Klebsiella pneumoniae could provide a source of proteinaceous material sufficient to allow the female flies to produce mature oocytes and eggs or alternatively, whether the bacteria could act as a beneficial supplementary food when given in addition to the usual laboratory proteinaceous food that consisted of a paste of sucrose and Yeast Autolysate. Overall, there was no evidence from any generation studied that female flies could produce eggs or mature oocytes on a bacterial diet above the levels attained with access to culture medium without bacteria. Similarly, there was no evidence that bacterial supplementation to a diet that included a paste of sucrose and Yeast Autolysate was more beneficial than when the paste was the sole source of proteinaceous food. There was an increase in mature oocytes per female with the number of generations of culture but the extent of increase was greater when sugar/Yeast paste was included in the diet. There was no evidence that mixtures of either bacterium species in nutrient broth or the broth itself was attractive to female B. tryoni over a distance of a few centimetres when the tested flies were caged at low density but flies of later generations did feed when offered either type of food at very close range.
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Relation of constant, daily fluctuating, and ambient feeding temperature to daily and accumulated consumption of Yeast Autolysate and sucrose by female Queensland fruit fly
Entomologia Experimentalis et Applicata, 2008Co-Authors: A Meats, G.l. KellyAbstract:Intake rates by the Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), of Yeast Autolysate and sucrose were clearly related to temperature in constant thermal regimes, but consumption occurred only in light. In regimes of fluctuating temperature, rates of consumption were not necessarily related to the temperatures that prevailed during the photophase, but were more consistently related to daily mean temperature and best related to day degrees per day above the gonadotrophic threshold of 13.5 °C. Day degrees per day could be related to age-specific changes in the daily rate of Yeast Autolysate and sucrose consumption, the rate of accumulated consumption of these foods, and thus the time taken to consume the amount of Yeast Autolysate known to be required for the attainment of sexual maturity. Consumption rate changed within 1 or 2 days of a change between a gonadotrophic regime and a non-gonadotrophic one (or vice versa), which is consistent with the known rapid effects of temperature change on ovarian maturation.
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Influence of the odour of fruit, Yeast and cue‐lure on the flight activity of the Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae)
Australian Journal of Entomology, 2000Co-Authors: Geraldene Dalby‐ball, A MeatsAbstract:Certain volatile substances increased the frequency of flights by Bactrocera tryoni (Froggatt) in laboratory arenas with artificial foliage, irrespective of the presence or absence of a visual cue (red fruit model). The odour of guava and iso-amyl acetate, but not nerol, increased the flight frequency of mature females. The odour of Yeast Autolysate had a similar effect on immature females (previously starved of the substance), but had no effect on mature females (previously fed on it). The flight activity of mature males increased in the presence of the odour of cue-lure. Ten per cent of flies landed on a red model within 7.5 min when in the presence of an odour, whereas only 1.7% did so when there was no odour. No flies landed on transparent models regardless of the presence or absence of odour.
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influence of the odour of fruit Yeast and cue lure on the flight activity of the queensland fruit fly bactrocera tryoni froggatt diptera tephritidae
Australian Journal of Entomology, 2000Co-Authors: Geraldene Dalbyball, A MeatsAbstract:Certain volatile substances increased the frequency of flights by Bactrocera tryoni (Froggatt) in laboratory arenas with artificial foliage, irrespective of the presence or absence of a visual cue (red fruit model). The odour of guava and iso-amyl acetate, but not nerol, increased the flight frequency of mature females. The odour of Yeast Autolysate had a similar effect on immature females (previously starved of the substance), but had no effect on mature females (previously fed on it). The flight activity of mature males increased in the presence of the odour of cue-lure. Ten per cent of flies landed on a red model within 7.5 min when in the presence of an odour, whereas only 1.7% did so when there was no odour. No flies landed on transparent models regardless of the presence or absence of odour.
