A novel process for preparing low-fat peanuts: Optimization of the oil extraction yield with limited structural and organoleptic damage

• Novel healthy, eco-friendly and efficient defatting process without using chemicals.
• Significant effect of pressure and water content on oil yield and deformation ratio.
• High oil extraction yields (70–80%) and low deformation ratio (<1%).
• Use of relatively low pressures (<10 MPa) for very short durations (3–4 min).
• Low-calorie peanuts with preservation of textural and organoleptic qualities.

The main purpose of this study was to extract the maximum amount of oil from peanuts without causing major damage and preserving their organoleptic quality after defatting. Accordingly, a successful, healthy, eco-friendly and economic defatting process for peanuts was implemented using mechanical oil expression, which was optimized by means of Response Surface Methodology. The results demonstrated that maximum extraction yields were obtained at a low initial moisture content (5–7% d.b.). Defatting and deformation ratios were mostly affected by the pressure and water content with high correlation coefficients (98.4% and 97.5%, respectively), and overall acceptability decreased following higher oil extraction yields. It was concluded that the optimum values for the product moisture content, pressure, and pressing duration were 5% d.b., 9.7 MPa and 4 min, respectively, with a defatting ratio of 70.6%. This resulted in an insignificant irreversible deformation ratio (<1%) and an overall acceptability of 7.6 over 10.