Tunable alkaline-modified microcrystalline cellulose for deacidification of corn oil

Advancing eco-friendly refining technologies that preserve key bioactives is vital for producing high-quality functional edible oils. In this work, corn oil was selected as a representative model to evaluate a sustainable deacidification strategy based on alkali-modified cellulose materials. Alkali-modified cellulose (AMC) adsorbents were developed by treating microcrystalline cellulose (MCC) with NaOH (5-50 %) and evaluated for their performance in corn oil deacidification. The adjustability of alkali concentration enables the preparation of AMC with specific adsorption capacities suited to oils of varying acid values. The AMC treated with 25 % NaOH achieved the highest deacidification efficiency (97.23 %) under optimized conditions (3 % dosage, 50 °C, 200 rpm, 90 min) for corn oil with an initial acid value of 6.51 mg KOH/g. The alkali treatment caused visible changes in the color, morphology, and transparency of AMC, reflecting the structural transformation induced by different alkali concentrations. Structural characterizations via SEM, TEM, XRD, and FTIR confirmed enhanced porosity and crystalline transformation conducive to free fatty acid (FFA) adsorption. AMC showed minimal impact on oil's peroxide value and fatty acid composition, with high retention of tocopherols (96.27 %) and phytosterols (91.17 %), though squalene loss was substantial (85.91 %). These findings indicate that AMC can be further developed into a tunable and selective deacidification approach for corn oil and potentially other edible oils, enabling precision refinement while minimizing nutritional loss.