الفهرس 
Flavour Compounds and its importance in foods:Only 14 pages are availabe for public view
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Abstract
Rania Menaaz Bayomy El-feky: Biosynthesis of Flavour Substances from Some Food Industrial Wastes. Unpublished M.Sc. Dissertation, Department of Food Science, Faculty of Agriculture, Ain Shams University, 2010.
Three strains of fungi were used namely Pleurotus ostreatus MHC 254, Pleurotus floridans MHC 237 and Agaricus biosporus GAMU 103 to produce ferulic acid and vanillin from agro-industrial by-products which cause a serious environmental disposal problem such as peanut hulls, wheat bran, date kernels and sugarcane bagasse which are a particular interest for the agriculture economy of temperate and subtropical countries, since they are produced in large quantities from food industry and food processing. Chemical compositions of tested agro-industrial by-products were achieved and the results showed that, a significant differents between lignin content in current agro-industrial wastes. Chemical Analysis of lignin content for by-products before and after inoculation with fungal strains were investigated, where, the initial content of lignin was 3.64% in wheat bran and after inoculation with fungal strains the results observed that, Pleurotus floridans MHC 237 was the highest efficient strain to degrade lignin and was 2.05% after 21 days of incubation. Inner layers of sugarcane have lignin content of 10.64% and after inoculation with Pleurotus floridans MHC 237 the results showed that it was the highest efficient strain to degrade lignin which was 7.08% after 21 days. The initial lignin content of peanut hulls was 43.34% and Pleurotus floridans MHC 237 has the highest efficient strain for degrading lignin which was 35.39% after 21 days. whereas the lignin content of date kernels was increased by increasing incubation period. The available ferulic acid was first obtained by using fungal strains of Pleurotus ostreatus MHC 254, Pleurotus floridans MHC 237 and Agaricus biosporus GAMU 103 and then bioconversion into vanillin and vanillic acid. Determination of ferulic acid using UV-spectrophotometer demonstrated that, extracts of Peanut hulls have increasing in ferulic acid and the strain Agaricus biosporus GAMU 103 recorded the highest values were 19.3 mg/g dry sample after 21 days of incubation. Wheat bran extracts have increasing in ferulic acid by using Pleurotus floridans MHC 237 which record the highest value (1.37 mg/g dry sample) after 14 days of incubation. Inner layers of sugarcane extracts have increasing in ferulic acid and the strain Agaricus biosporus GAMU 103 record the highest value which was 6 mg/g dry sample after 14 days of incubation. Outer layers of sugarcane extracts caused to increase ferulic acid and the strain Agaricus biosporus GAMU 103 record the highest value which was 5.92 mg/g dry sample after 7 days of incubation. Determination of vanillin by UV-spectrophotometer showed that, Peanut hulls extracts produced higher amount of vanillin and the strain Agaricus biosporus GAMU 103 record the highest obtained value which was 16.82 mg/g dry sample after 7 days of incubation. Wheat bran extracts have increased in vanillin and the strain Agaricus biosporus GAMU 103 record the highest value which was 4.28 mg/g dry sample after 21 days of incubation. Inner layers of sugarcane extracts have increased in vanillin and the strain Agaricus biosporus GAMU 103 record the highest value which was 13.22 mg/g dry sample after 14 days of incubation. Outer layers of sugarcane extracts have decreased in vanillin and the strain Pleurotus floridans MHC 237 record the lowest value which was 4.8 mg/g dry sample after 21 days of incubation. HPLC analysis for produced ferulic acid and vanillin were determined before and after inoculation with fungal strains. Peanut hulls extracts recorded the highest value of biosynthesis ferulic acid with the fungus strain Pleurotus floridans MHC 237 which was 59.38 mg/l, and the highest value of vanillin in the strain Agaricus biosporus GAMU 103 which was 19.04 mg/l, wheat bran, and the highest biosynthesis of vanillin was 34.71 mg/l in Agaricus biosporus GAMU 103 after 7 days of incubation. Inner layers of sugarcane recorded the highest values of ferulic acid and vanillin biosynthesized were 25.91 and 621.15 mg/l in Agaricus biosporus GAMU 103 after 21 days, respectively. Outer layers of sugarcane recorded the highest values of ferulic acid and vanillin biosynthesized were 45.90 and 287.27 mg/l in Agaricus biosporus GAMU 103 after 14 days, respectively. The obtained results demonstrated that, the potential application of the used strategy for biosynthesis of vanillin from by-products must be used under suitable conditions.
Key words: Biovanillin - Agro-industrial by-products - Ferulic acid – Bioconversion-TLC – HPLC analysis – UV-spectrophotometer - Lignin content.