title: Acidification and starch behaviour during co-fermentation of cassava (Manihot esculenta Crantz) and soybean (Glycine max Merr) into gari, an African fermented food.
abstract: Changes in acidification and starch behaviour were investigated during co-fermentation of cassava and soybean into gari, an African fermented product. Non-volatile acidity, pH and starch content were evaluated using standard analytical methods. Starch breakdown and pasting characteristics were also analysed using a Brabender viscoamylograph. Fermentation caused significant variations in the pH, non-volatile acidity and starch concentration. The pH decreased with concomitant increases in non-volatile acidity during co-fermentation of the cassava dough. Soy fortification up to 20% caused only minimal effects on the pH, titratable acidity and starch content during the fermentation period. Starch content decreased from 69.8% to 60.4% within the 48 h fermentation time in the unfortified sample, with similar trends noted at all levels of fortification. Starch pasting characteristics showed varied trends in pasting temperature, peak viscosity, viscosity at 95 degrees C and at 50 degrees C-hold with increasing fermentation time and soybean concentration. Cassava could be co-fermented with soybean up to 20% concentration during gari processing without significant effect on its process and product quality characteristics.
authors.affiliation: Department of Nutrition & Food Science, University of Ghana, Legon-Accra, Ghana. e_afoakwa@yahoo.com
authors.forename: Emmanuel Ohene
authors.initials: EO
authors.lastname: Afoakwa
authors.forename: Edem John
authors.initials: EJ
authors.lastname: Kongor
authors.forename: George Amponsah
authors.initials: GA
authors.lastname: Annor
authors.forename: Randy
authors.initials: R
authors.lastname: Adjonu
mesh_terms: D000354:Africa, Western; D055598:Chemical Phenomena; D003296:Cooking / Q000379:methods*; D005285:Fermentation; D005527:Food, Fortified / Q000032:analysis*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D002365:Manihot / Q000737:chemistry*; D035281:Plant Tubers / Q000737:chemistry; D011786:Quality Control; D012212:Rheology; D012639:Seeds / Q000737:chemistry; D045730:Soy Foods / Q000032:analysis; D013025:Glycine max / Q000737:chemistry*; D013213:Starch / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D013997:Time Factors; D017186:Titrimetry; D014783:Viscosity
chemical_list: D013213:Starch