Effect of Heat Treatment and Fermentation on Anti-Nutrients Content of Lima Bean (Phaseolus lunatus) During Production of Daddawa Analogue

Aim: To produce daddawa analogue (a fermented condiment) from Lima bean (Phaseolus lunatus) seeds which should have safe levels of anti-nutrients comparable to daddawa from locust bean (Parkia biglobosa) seeds.
Design of the Study: Lima bean and locust bean seeds were separately heat-processed and subjected to natural fermentation for 72 hours to produce daddawa analogue and daddawa respectively.
Place and Duration of Study: Department of Food Science and Technology and Central Science Laboratory, Obafemi Awolowo University, Ile-Ife, Nigeria between March 2010 and June 2011.
Methodology: The pH, titratable acidity, and the anti-nutrients (tannin, phytate, cyanide, trypsin inhibitor) of the fermenting samples were evaluated every 12 hours during fermentation.
Results: pH increased (P = .05) from 7.46 at 0 h to 8.50 after 72 h and from 7.50 at 0 h to 8.74 at 72 h of fermentation in lima bean and locust beans respectively. Titratable acidity decreased in the fermented lima beans from 0.216 at 0 h to 0.045 mg lactic acid/g at 72 h of fermentation. All anti-nutrients analyzed decreased with fermentation time. Tannin content decreased significantly (P = .05) from 19.0 ± 0.10 at 0 h to 2.0 ± 0.01mg/kg at 72 h and from 9.50 ± 0.02 at 0 h to 3.06 ± 0.01 mg/kg at 72 h of fermentation in lima beans and locust beans respectively. Fermentation significantly decreased phytate content (P = .05) from 22.0 ± 0.03 at 0 h to 7.0 ± 0.01mg/kg at 72 h in lima beans. Cyanide content decreased significantly (P = .05) from 0.97 ± 0.01 at 0 h to 0.25 ± 0.01mg/kg at 72 h and from 15.0 ± 0.05 at 0 h to 0.29 ± 0.10 mg/kg at 72 h of fermentation in lima beans and locust beans respectively. Trypsin inhibitor content also decreased significantly (P = .05) from 4.40 ± 0.10 at 0 h to 1.76 ± 0.02 mg/kg at 72 h and from 0.24 ± 0.0 at 0 h to 0.10 ± 0.1 TIU/g at 72 h of fermentation in lima beans and locust beans respectively.
Conclusion: The study has shown that daddawa analogue from lima beans was comparable to daddawa from locust beans in terms of anti-nutritional contents.