Lipids of Quercus Acorns: Health Implications, Oxidative Stability, and Food Applications

Acorns (Quercus spp.) have re-emerged as a sustainable, underutilized food resource, and their lipid fraction has attracted growing scientific interest because of its distinctive composition and technological potential. Acorn lipids typically represent 5–12% of acorn dry weight, ranging from 0.75% (Q. vulcanica) to over 17% (Q. rubra), and are dominated by unsaturated fatty acids, mainly oleic acid (up to ~70% of total fatty acids) and, to a lesser extent, linoleic acid, alongside minor bioactive compounds such as tocopherols (31.60–1486 mg/kg oil), phytosterols (2449–8797.92 mg/kg oil), carotenoids (β-carotene: 473–1421 mg/kg DM), and long-chain aliphatic alcohols (2198.81–2248.87 mg/kg oil) associated with antioxidant, anti-inflammatory, hypocholesterolemic, and cardioprotective effects. Despite their high degree of unsaturation, acorn oils maintain good oxidative stability during up to 180 days of storage under dark conditions at room temperature, partly due to these endogenous antioxidants, and their lipids participate in starch–lipid interactions that influence starch digestibility, glycemic response, and the functional properties of acorn-based foods, including bakery, gluten-free, and pasta products. Based on a comprehensive literature search of the Web of Science database through June 2026, this review provides a comprehensive synthesis of acorn lipids. Critical analysis shows that most evidence derives from whole acorn flour rather than isolated lipids, that reporting units remain inconsistent across studies, and that dedicated intervention trials using acorn oil are lacking—gaps that should guide future research. This review serves as a critical bridge between botanical lipidomics and food engineering, providing a framework for the standardized valorization of Quercus species in the global transition to sustainable, plant-based functional ingredients.