Effects of steeping condition and germination time on the alpha-amylase activity, phenolics content and malting loss of Nigerian local red and hybrid short Kaura sorghum malts

• Published in: Food chemistry Vol. 58; no. 4; pp. 289 - 295
• Main Authors: Iwuoha, Chinyere I., Aina, Joshua O.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.04.1997; Elsevier
• Subjects: Beers; Biological and medical sciences; Fermented food industries; Food industries; Fundamental and applied biological sciences. Psychology; Soaking; Enzyme; Germination; Malting; Mass loss; Enzymatic activity; Glycosidases; Phenols; Cereal; Hydrolases; Sorghum (food); α-Amylase; O-Glycosidases
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/0308-8146(95)00215-4

The effects of steeping condition (STC) and germination time (GMT) on the phenolics content (PC), alpha-amylase activity (DP) and malting loss (ML) of Nigerian local red (LRS) and hybrid (HSK) grain sorghum were investigated in 6-day micro-malting trials. Air-rested steeping (ARM) effected the highest increase in DP of both LRS (51.7%) and HSK (30.2%), which occurred on the fifth day of germination, while the lowest increase was from the low-temperature steeping treatment (LTM) in LRS (12.6%) and HSK (5.32%), based on the control (CSM). Reduction in PC was proportional to GMT. The greatest reduction, which occurred on the sixth day, in LRS (71.4%), was caused by formalin re-steeping of ARM germinates (FRM), while the least reduction was caused by ARM (28.3%) in HSK. Malting loss (ML) increased with GMT while ARM caused the greatest loss (46.2%) in the 6-day LRS malt. On average, ML of LTM was not significantly different from that of CSM in HSK, but it was in LRS ( P ⩽ 0.05). Results of second-order ANOVA showed that the main factors—STC (A), GMT (B) and sorghum variety, SGV (C)—have significant influences ( P ⩽ 0.025) on DP and ML, while SGV had none on PC. The interaction A × B affected DP ( P ⩽ 0.10) and ML ( P ⩽ 0.005); A × C exerted no statistically significant effects on any of the three quality attributes, while B × C influenced only DP ( P ⩽ 0.05).