Work

Effect of different heating pretreatment methods on physicochemical properties of pressed walnut oils and functional properties of walnut protein isolates

Year: 2025

Type: article

Abstract: In this study, three heating pretreatment methods, including far infrared heating (FIH), stir-frying heating (SFH), and microwave radiation heating (MRH), were applied to raw materials before the cold pressing extraction of walnut oil (WO). The quality properties of WO and walnut protein isolate (WPI) were comparatively studied. The results showed that different pretreatment methods significantly affected the physicochemical properties, oxidative stability, and antioxidant activity of different WO (p < 0.05). FIH pretreatment notably improved the yield, antioxidant activity, oxidation stability, and total polyphenol content of WO (p < 0.05). Significant effects were detected on the flavor of WO through different pretreatment methods. Additionally, the WPI obtained after FIH pretreatment exhibited higher protein solubility, water-holding capacity, and emulsion stability. These findings indicate that FIH pretreatment is a simple and effective strategy to obtain high-quality WO and WPI. This study will provide a theoretical basis for the preparation and application of WO and WPI.

Source: LWT

DOI: 10.1016/j.lwt.2025.117885