Biochemical changes induced by five pathogenic fungi on seeds of Hibiscus sabdariffa (Yakwa)
Different biochemical analysis were carried out to determine the changes induced by some fungi inoculated on Hibiscus sabdariffa linn seed for 14days. The inoculated fungi are Aspergillus niger Van Tieghem, Aspergillus flavus Link Ex fr, Fusarium oxysporum Schlecht, Penicillium chrysogenum Thom and Penicillium roqueforti Thom. The moisture content of fungi– inoculated seeds increased (p=0.05) when compared with the uninoculated control. Fusarium oxysporum (64.7%) caused the highest increase in moisture followed by Penicillium chrysogenum (61.0%), Aspergillus flavus (58.9%) and Aspergillus niger (58.2%). There was a significant decrease (P=0.05) in Dry Matter from the control seeds when compared to the fungi inoculated seeds. There was also a decrease in carbohydrate of fungi inoculated seeds as when compared with the uninoculated control. The protein content of the fungi inoculated seeds, increased significantly when compared to the uninocualted control (25.5%). Penicillium chrysogenum (29.9%), Fusarium oxysporum (28.7%), Aspergillus flavus (28.4%), Aspergillus niger (27.8%) increased in that order. The increase could be due to the presence of proteinaceous mycelium in the fungi. There was a significant decrease (P=0.05) of lipid from the uninoculated control (10.38%) when compared to the fungi inoculated seeds. The decrease in oil content could be due to the hydrolysis of oil to free fatty acid. There was a drastic and significant decrease in fibre caused by utilization during fermentation. There was significant increase (P=0.05) in ash, when compared to the uninoculated control. This is due to the presence of minerals like potassium and phosphorous in the mycelia of the fungi.
Keywords: Hibiscus sabdariffa Linn Seed, Biochemical changes and fungi