Effect of thermal treatments on the storage life of pearl millet (Pennisetum glaucum) flour

Abstract

Effect of pre-milling treatments, viz. roasting and hydrothermal treatment was evaluated on pearl millet [Pennisetum glaucum (L) R Br] flour stored at ambient condition (average maximum and minimum temperatures 33.1±4oC and 21.4±2oC, respectively, and 84.4±2% RH) and controlled condition (30±1oC at 50±2% RH) packed in zip-lip low density polyethylene (LDPE) pouches of 10 µm thickness having permeability 23.13g/m2 24h. Roasting and hydro thermal treatment significantly reduced fat acidity by 8% and 12%, phytic acidity by 10% and 4% and trypsin inhibitor activity by 9% and 5%, respectively, of pearl millet flour. It was observed that pearl millet flour can be stored at controlled condition in superior form than ambient condition. Storage period had significant (P<0.05) effect on moisture content, fat acidity, phytic acid and trypsin inhibitors activity of pearl millet flour. It was found that untreated, roasted and hydrothermally treated pearl millet flour can be stored up to 2, 2 and 30 days at ambient conditions and 3, 3 and 45 day, respectively, at controlled condition without undue deterioration in quality.

Keywords

• Fat acidity
• Moisture content
• Pearl millet flour
• Phytic acid
• Storage
• Trypsin inhibitors activity