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Kinetics of deoxynivalenol degradation by Aspergillus oryzae and Rhizopus oryzae in submerged fermentation
Garda-Buffon, Jaqueline;Badiale-Furlong, Eliana;
Journal of the Brazilian Chemical Society , 2010, DOI: 10.1590/S0103-50532010000400018
Abstract: the objective was to evaluate the capacity of aspergillus oryzae and rhizopus oryzae to degrade deoxynivalenol (don) during submerged fermentation. the submerged medium utilized was sterile distilled water with 1μg ml-1 don, added and inoculated with 4 × 106 spores ml-1 of the fungal species. sampling was performed every 48 h to 240 h. don analyses included residual mass, percentage and velocity of degradation. residual mass of don in the collected medium was extracted by liquid-liquid partition and quantified by gas chromatography through derivation with trifluoroacetic anhydride. the time required for the largest don degradation was 96 h and 240 h by aspergillus oryzae and rhizopus oryzae respectively, and degradation rate were 0.62 and 0.54 μg h-1, respectively. rhizopus oryzae caused the largest decrease in don at around 90% in 240 h, while aspergillus oryzae caused the most rapid degradation with a 74% reduction of don at 96 h.
Reduction of hexavalent chromium by Rhizopus Oryzae
M Sukumar
African Journal of Environmental Science and Technology , 2010,
Abstract: The ability of Rhizopus oryzae to reduce Cr6+ was evaluated in batch microcosms. The optimum pH of R. oryzae growth was between 6.0 and 7.0. The maximum chromium reduction efficiency of 91.15% and biomass growth was achieved at a pH of 7, temperature of 37°C, with an initial Cr6+ concentration of 400 ppm and incubation period of 72 h. Monod and Haldane models were used to describe the chromium reduction data and the specific growth rate constant value was calculated as 0.082 and the reduction rate was found to be highest at 400 mg Cr6+ /l. The high removal of chromate by R. oryzae indicates a feasible, economical technique for chromate removal from industrial wastewater effluents.
Current Commercial Perspective of Rhizopus oryzae: A Review  [PDF]
Barnita Ghosh,Rina Rani Ray
Journal of Applied Sciences , 2011,
Abstract: The present study reviews the potentiality of Rhizopus oryzae, a potent saprophytic and pathogenic fungus to produce a wide spectrum of metabolites, in the form of enzymes, esters, organic acids, volatile materials, polymers and bioalcohols. A number of extra and intra cellular enzymes are found to be synthesized by various strains of Rhizopus oryzae that includes cellulaes, hemicellulases, pectinases, tannase, phytase, amylase, lipase, protease and other enzymes of immense industrial importance. The fungus is a rich source of lactic acid and is widely studied as a commercially perspective producer of L(+)-LA. In many strains, the end product of glycolysis is channeled to ethanol by the enzyme pyruvate decarboxylase and therefore may be used for the production of alcohol. Biodiesel can also be produced by methanolysis and transesterification reactions employing specific strains of R. oryzae having the relevant enzymes. Dry mycelium of Rhizopus oryzae are proved effective for efficiently catalyzing the synthesis of different flavor esters. Since the Joint FAO/WHO expert committee on food Additives (JEFCA) and Food and Drug Administration, Department of Health and Human Services, USA certified the enzymes extracted from Rhizopus oryzae may be used as food additives for human consumption, this fungal group may be exhaustively used for commercial purposes.
Effect of Freezing Conditions on the Ripening Process and the Quality of Cheese
Arnold Reps,Krystyna Wisniewska,Irmina Jarmul,Anna Brakoniecka-Sikorska
Pakistan Journal of Nutrition , 2005,
Abstract: Kortowski cheese (M nster type) was salted for 100, 75, 50 and 25% of their standard salting time, which is 48 hours. Cheese after 3 weeks of ripening and cheese immediately after salting were stored for 6 and 12 months at -27°C. Cheese of lower salting level ripened faster, both after salting and after frozen storage. The process of protein degradation occurred during frozen storage of ripe cheeses. The content of N-amino acid in ripe cheese after frozen storage and in cheese ripening after storage was almost twice as high as in the cheese that ripened after salting. Separations on Sephadex gel confirm the process of protein degradation during frozen storage of cheese. The conducted research indicated that frozen storage is recommended for Kortowski cheese of reduced salt content and the most favourable solution is to conduct the process of cheese ripening after thawing.
The influence of ripening process on trapist cheese abatement  [cached]
Slavko Kirin
Mljekarstvo , 2002,
Abstract: In this paper the influence of ripening process on Trapist cheeseabatement, taken into account on cheese yield calculation, was investigated. Three different ripening processes were investigated: ripening process with rind washing and without protecting coating application, ripening process with protecting coating application and cheese ripening in plastic shrinkable pouch. The highest abatement was found in the case of cheese ripening on traditional way i.e. without protecting coating applied and with rind washing during ripening period. Slightly lower abatement value showed cheeses with protecting coating applied, while the negligible abatement was noticed in cheese packaged into a pouch. The highest abatement values were noticed during the first 10 days of cheese ripening process with and without protective coating applied. After that time the steady state of abatement value was reached. In this case slightly higher values were obtained in the case of cheeses with protective coating. It is evident that the highest influence on abatement value is during the first phase of Trapist cheese ripening process.
Effect of Ripening Time on Mineral Contents of Herby Cheese
H. Durmaz,Z. Tarakci,E. Sagun,H. Sancak
Journal of Animal and Veterinary Advances , 2012,
Abstract: Herby cheese is a salted traditional cheese manufactured in the Eastern and South-eastern of Turkey. Its name, herby, comes from adding herb in cheese. The aim of this study was to assess the changes in the mineral contents and some chemical parameters in herby cheese during 90 days of ripening. The total solids, ash, salt, Na, Cu, Fe, Mn contents and pH values increased significantly (p<0.05), while Ca, Mg and Zn contents decreased significantly (p<0.05) during ripening. P, Co, Cr, Ni and Cd contents of the cheeses were not significantly (p>0.05) altered during ripening. The results indicated that the mineral of herby cheese showed a very variable behaviour during ripening due to likely manufacturing technology.
Role of Fungal Enzymes in the Biochemistry of Egyptian Ras Cheese during Ripening Period
Husain A. El-Fadaly, Sherif M. El-Kadi, Mohamed N. Hamad, Abdelhady A. Habib
Open Access Library Journal (OALib Journal) , 2015, DOI: 10.4236/oalib.1101819
Abstract: Six fungal genera including thirteen species isolated from Ras cheese samples were tested for assimilation of lactose, skim and fat milk hydrolysis. All fungal strains gave negative results in lactose assimilation except A. nidulans which produced acid without gas after 24 hr and produced a soluble red pigment after 10 days of incubation. All tested fungal strains showed positive results for protein hydrolysis on modified Czapek agar (MCA) medium by skim milk addition. The presence of casein in the cultural medium caused a strong growth comparing with the growth on control. Changing of growth resulting from milk casein addition was in the highest values in the cultures of Rhizopus stolonifer, A. flavus and A. niger being 87.81, 58.32 and 41.58 mm, respectively and the lowest values were A. nidulans and Geotrichum candidum being 7.09 and 13.71 mm. All strains gave positive results for lipolysis except Aspergillus nidulans on plates containing modified Czapek agar (MCA) medium by milk fat addition. The fungal growth diameter was varied from 9.17 to 30.67 mm in the case of A. niger and A. alliaceus, respectively. The presence of milk fat in the cultural medium caused a changing of growth in the case of A. glaucus; A. alliaceus and A. flavus being 28.11, 27.42 and 25.19 mm, respectively and A. niger, Rhizopus stolonifer and A. flavipes achieved lowest values being 5.62, 10.80 and 11.82 mm, respectively. Moisture percentage was gradually decreased during storage period (3 months at 15.5?C) from 31.29% in the first month to 30.25% in the third month. Fat percentage was 24.05% in fresh Ras cheese wheels, which increased to 25.89% after salting period (45 day). During ripening period the values of fat in Ras cheese wheels were 30.53%, 35.98% and 32.38% after the 1st, 2nd and 3rd month, respectively. The highest values of total nitrogen, soluble nitrogen and non-protein nitrogen percentages of Ras cheese wheels were 4.18%, 43.97% and 18.98%, respectively. These values tended to increase with advanced storage.
Fermentasi Etanol dari Ubi Jalar (Ipomoea batatas) oleh Kultur Campuran Rhizopus oryzae dan Saccharomyces cerevisiae  [PDF]
Bioteknologi , 2004,
Abstract: Saccharomyces cerevisiae was known to ferment glucose into ethanol, but S.cerevisiae could not ferment starch into ethanol. This research was to studyethanol fermentation from sweet potato by mix cultures of Rhizopus oryzae and S. cerevisiae. The medium was prepared 10, 15 and 20%(b/v) sweet potato in aquadest into jam’s bottle. The media (50 mL) was inoculated with 1 mL S. cerevisiae 1x106 cfu/mL. After covered by Whatman paper No.41, the bottle added with another 50 mL medium and inoculated with 1 mL R. oryzae 1x105 cfu/mL. Concentration of reducing of sugar, starch, ethanol and biomass was measured everyday. The result showed that 10% sweet potato medium produced the highest content of ethanol that was an amount 2.647% followed by 15% sweet potato medium was 2.623% and 20% sweet potato medium was 2.163%. The optimum fermentation duration to produce the highest content of ethanol was 5 days.
Colour traits in the evaluation of the ripening period of Asiago cheese  [cached]
Giorgio Marchesini,Stefania Balzan,Severino Segato,Enrico Novelli
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2009.s2.412
Abstract: The research was carried out on Asiago d’Allevo cheese samples produced in a single farm located in the Altopiano dei Sette Comuni (above 1000m a.s.l.). After 6-12-18 and 36 months of ripening, samples were analyzed for quality traits, in order to evaluate the effect of ripening on colour and gross composition. As expected crude protein and fat significantly increased through the considered period. Ripening led to a significant decrease of L*, a* and b* values. Lightness showed a negative relationship with crude protein, meanwhile a* and b* were both negatively related to fat content. Concerning L*, the trend could be explained by water loss and N-soluble compounds concentration, which could alter protein matrix. a* and b* reduction was probably related to degradation processes such as lipolysis, which seemed to be extensive in hard and long ripened cheese. Ripening affected significantly the light reflectance at all λ with green cheese having the higher values.
Linoleic and linolenic acids analysis of soybean tofu with Rhizopus oryzae and Rhizopus oligosporus as coagulant
Nusantara Bioscience , 2009,
Abstract: Sudaryatiningsih C, Supyani. 2009. Linoleic and linolenic acids analysis of soybean tofu with Rhizopus oryzae and Rhizopus oligosporus as coagulant. Nusantara Bioscience 1: 110-116. The aims of this research are to know the potency of Rhizopus oligosporus and Rhizopus oryzae as a coagulant in tofu processing for increasing the amount of linoleic and linolenic acids, and to know the time that needed by R. oligosporus and R. oryzae for increasing the amount of linoleic and linolenic acids. It uses PDA for inoculating fungi, and it is done at Sub-Lab Chemistry, Central Laboratory for Mathematics and Natural Sciences, Sebelas Maret University, Surakarta. The tofu making was done in “Dele Emas” Tofu Factory, Surakarta. Analysis of linoleic and linolenic acids were done by Gas Chromatography, in LPPT-UGM Yogyakarta. The conclusion of this research are R. oligosporus dan R. oryzae having a potency as a coagulant in tofu processing for increasing the amount of linoleic and linolenic acids. R. oryzae needs 18 hours to coagulate the tofu, and R. oligosporus needs 12 hours for the same process. The highest amount of linoleic and linolenic acids were obtained by R. oryzae at 6 hours of fermentation (0.26% and 0.14%), and 24 hours of fermentation by R. oligosporus (0.06% and 0.04%).
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