LAUSR

BACKGROUND Soaking and air-resting are processing steps in malting. It has been reported to increase metabolic and enzyme activities in rice paddy due to exposure of the grain to atmospheric oxygen. This study evaluated the effect of soaking and air-resting on the phytochemical composition of Piper guineense seeds. The seed extracts were prepared as follows: soaking the seeds in water for four hours, air-resting for 30, 60, 90, and 120 minutes and re-soaking for another four hours. The out-of-steep seeds were milled and an extract was formed by tissue homogenization and maceration using ethanol. The phytochemical, antioxidant, and antibacterial properties of the seed extract were determined using standard methods. RESULTS The alkaloid, flavonoid, saponin, tannin, and total phenol contents were 0.126-0.268, 0.091-0.172, 0.080-0.123, 0.00-0.107, and 0.447-0.908 g kg-1 respectively. The antioxidant properties (reducing power) of the seed extracts were concentration-dependent and ranged from 1.08-3.24 g kg-1 at 8 mg/ml, 1.14-3.47 g kg-1 at 16 mg/ml, 1.30-3.35 g kg-1 at 24 mg/ml, 1.26-3.11 g kg-1 at 32 mg/ml and 1.13-3.04 g kg-1 at 40 mg/ml. The antibacterial activities against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa showed that at 100 mg/ml, the inhibition zone diameters of the seed extracts ranged from 10 - 23 mm. CONCLUSION Soaking and air-resting of Piper guineense seeds increased the phytochemical components of the seeds. The extracts from the seeds air-rested for 30 minutes showed the highest phytochemical contents and had the highest antioxidant and antimicrobial properties. This article is protected by copyright. All rights reserved.