Utilization of Some Sugar Industrial by- Products and Fructan Storing Crops for Bioproduction of Citric Acid

Document Type : Original Article

Authors

1 Sugar Crops Research Institute, Agric. Research Center, El-Sabahia, Alex. Egypt

2 Food Science and Technology Dept, Faculty of Agric.,Univ of Alex, El-Shatby., Egypt

Abstract

Two sugar industrial by-products, cane bagasse “SCB” and sugar beet molasses “SBM” along with two fructan storing crops ,chicory rootsCR” and Jerusalem artichoke tubers “JA”, alone or after mixing were utilized as a carbon source in fermentation medium to produce citric  acid  by Aspergillus niger strainGQ890276. It was found that the proximate composition and total sugars content of these agro-materials   played a role in terms of citric acid production . Moisture  ranged from 6.55 to 23.15%; crude fat from zero to 1.55%; crude protein from  3.27 to 8.53%; crude fiber from zero to 47.46% , ash from3.29 to 8.93% ,nitrogen free extract from 44.83 to 87.06 %  and total sugar 8.11 to 87.06% among  these materials. The fermentation media either containing mixture of CR +SCB and/or CR as carbon source gave  high citric acid yield after 7 days of fermentation comparing with  other used  carbon sources. The citric acid yield was 59.36 g/L in  CR +SCB   medium .It was 87.80% when calculation was  based on the amount of consumed fermentable sugars. Also this media  gave the high  biomass ( 22.90 g/L)yield.  

Main Subjects