Development of in-situ enzymatic treatment for flavor and nutrients enhancement of strong fragrant rapeseed oil

Trade-offs between intense flavor development and nutrient retention challenge the production of strong fragrant rapeseed oil (SFRO). Conventional enzymatic treatments often require seed crushing, causing premature volatile loss, or exogenous sugar addition, compromising clean-label status. This study developed a novel in-situ enzymatic strategy targeting intact rapeseeds to overcome these limitations. Notably, for the first time, sucrase was identified as a highly efficient biocatalyst for liberating endogenous reducing sugars (glucose and fructose) from rapeseeds to fuel the Maillard reaction. A synergistic dual-enzyme system comprising sucrase and Flavourzyme 1000 L was optimized, which significantly enriched flavor precursors within the intact seed matrix without disrupting structural integrity. Under optimized mild roasting (160 °C/25 min), the in-situ treated oil exhibited a superior nutty aroma dominated by N-heterocycles (22172.4 μg/kg) while minimizing burnt-smelling phenols. Crucially, this mild processing maximized the retention of thermosensitive nutrients, yielding exceptional levels of phytosterols (9163.0 mg/kg) and tocopherols (904.5 mg/kg). Techno-economic analysis confirmed the method's sustainability through enzyme recyclability and reduced water consumption. This work provides a pioneering, clean-label compatible, and cost-effective paradigm for high-quality edible oil processing, highlighting the untapped potential of sucrase in flavor modulation.