36B-15 |
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G. F. MEHYAR, Dept. of Food Science, Univ. of Manitoba, 250 Ellis Bldg., Winnipeg, R3T 2N2, Canada, S. A. Ibrahim, Food Science & Nutrition, North Carolina A&T State Univ., Dept. of Human Environment & Family Sciences, 171-B Carver Hall, Greensboro, NC 27411-1064, and K. S. Al-Delaimy, Nutirition and Food Technology, Univ. of Jordan, Faculty of Agriculture, Amman, Jordan. Citric acid is widely used by the food, pharmaceutical, and chemical industries as a major substrate for the production of a variety of products. There have been increased interest in using natural resources such as fruit sugars for the production of citric acid. Research has shown that dates, figs, carob pods, kumara, taro and sugarcane are good substrates for citric acid production by A. niger. The objective of this study was to determine the ability of Aspergillus niger to produce citric acid from natural carbohydrate sources; date and sweet whey. The uses of other supplements to increase productivity were evaluated. Two strains of A. niger (ATCC 6275 and 9642) were grown in media containing different concentrations of date extract or molasses fortified with whey, methanol or tricalcium phosphate. The fermentation experiments were conducted at 25 ºC for 12 d. and samples were withdrawn at different time intervals and analyzed for citric acid content. Results showed that high amounts of citric acid was produced by A. niger ATCC 6275 in 20 % molasses in whey with citric acid concentration of 32.4 g/L. When methanol and tricalcium phosphate were added, significant increase in citric acid production was recorded. Citric acid concentrations were 38.4 and 42.4 g/l, in media fortified with methanol and tricalcium phosphate respectively. Our results indicates that the addition of sweet whey, methanol and tricalcium phosphate date or molasses could have a significant influence on the production of citric acid by A. niger.
Session 36B, Biotechnology: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |