Effect of Experimental Variables on the Malting Performance of Nigerian Maize Oba Super 2 Variety

Background: The Nigerian cultivar, Oba Super 2 (OS2) maize is inexpensive but under- utilized owing to poor development of malting technology for brewing.

Aim: To study the effects of experimental variables on the malting performance of Nigerian maize Oba Super 2 variety.

Study Design: Exploratory.

Place and Duration of Study: Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Nigeria, between March, 2018 to September, 2019.

Methodology: Certified Oba Super 2 maize variety was obtained from Premier Seed Limited, Zaria. The grain sample was malted at varying steeping (S) period (S30, S36 and S42 hours), different germination (G) period (0, 1, 2, 3, 4 and 5 days) and varying kilning (K) temperatures (45, 50 and 55°C) to determine the malting performance. The properties of the un-malted and malted maize were determined using standard methods. Data were analysed using analysis of variance (ANOVA) at P < 0.05.

Results: The malting loss (ML) was significantly higher (P < 0.05) at different steeping period, on the fifth day of germination (G5). The cold water extract (CWE) was significantly higher (P < 0.05) on the fourth day of germination (G4) kilned at K50. The values for hot water extract (HWE) were significantly higher (P < 0.05) on the G4 at K45, K55 and K50, respectively, while free alpha amino nitrogen (FAN) values were significantly higher (P < 0.05) on the G4, all kilned at K50. The values for diastatic power (DP) were significantly higher (P < 0.05) on the G5, kilned at K50, while the cold water soluble protein (CWS-P) was significantly higher (P < 0.05) on the G3 kilned at K50.

Conclusion: The results indicated that longer steeping and germination periods as well as moderate kilning temperature contributed maximally in improving the malting properties and high extract yields.