High-oleic rapeseed oil quality indicators and endogenous antioxidant substances under different processing methods.

Area of Science:

• Agricultural Chemistry
• Food Science and Technology
• Plant Biochemistry

Background:

• High-oleic rapeseed oil (HORO) is valued for its unique fatty acid profile and potential health benefits.
• Processing methods significantly influence the oil's physicochemical properties, antioxidant content, and overall quality.
• Optimizing extraction techniques is crucial for maximizing the yield and preserving valuable bioactive compounds in HORO.

Purpose of the Study:

• To evaluate the impact of different pretreatment (microwave, roasting) and processing (cold pressing, hexane extraction, subcritical butane extraction, aqueous enzymatic extraction) methods on HORO.
• To analyze the effects of these technologies on HORO's physicochemical properties, endogenous antioxidants, and antioxidant capacity.
• To identify the most effective method for producing high-quality HORO with enhanced nutritional value and stability.

Main Methods:

• Investigated various oil extraction techniques including cold pressing, hexane extraction, subcritical butane extraction, and aqueous enzymatic extraction.
• Applied microwave and roasting as pretreatment methods prior to oil extraction.
• Utilized hierarchical clustering and principal component analyses for comprehensive data evaluation.

Main Results:

• Oil yields ranged from 35.4% to 59.7% across different processing methods, with no significant alterations in fatty acid composition.
• The microwave pretreatment-hexane extraction (M-HE) method yielded significantly higher concentrations of tocopherols (688.4 mg/kg), polyphenols (1007.76 mg/kg), and phytosterols (1810.6 mg/kg).
• M-HE demonstrated superior antioxidant capacity, evidenced by high DPPH, FRAP, and ABTS assay values, indicating strong free radical scavenging activity.

Conclusions:

• Microwave pretreatment followed by hexane extraction (M-HE) is a highly effective method for producing high-quality high-oleic rapeseed oil.
• The M-HE process significantly increases the levels of key antioxidants like tocopherols, polyphenols, and phytosterols in HORO.
• This optimized processing approach offers a promising strategy for enhancing the stability and nutritional value of high-oleic rapeseed oil for various applications.