This study investigated the effect of chickpea flour (CF) on the staling behavior of gluten-free bread (GFB) by comparing a formulation containing 50% rice flour (RF) and 50% CF (CFB) with a control bread based on rice flour supplemented with whey protein (RFB). Bread samples were stored at room temperature for up to 7 days. Changes in color, reflectance, starch and protein structure, specific volume, crumb structure, texture, and staling kinetics were monitored. CFB exhibited a darker and more yellow crumb and crust, with lower reflectance intensity, and showed greater color stability during storage. Fourier-transform infrared (FTIR) spectroscopy revealed higher overall starch crystallinity and more stable relative crystallinity degree (RCD) values in CFB (58.74–59.05%) compared to RFB (46.19–40.52%) throughout storage, indicating early amylose-driven ordering and a more stable molecular organization of starch. Protein secondary structure analysis showed that CFB had a higher β-sheet content (35.05–37.49) than the RFB formulation (30.37–31.16), indicating stronger protein aggregation. In contrast, macroscopic quality parameters showed that CFB had lower specific volume (1.65 vs. 1.93) and porosity (17.17 vs. 21.01 cm³/g) than RFB, resulting in higher hardness (15.92 vs. 6.15 N) and accelerated staling kinetics (k_corr) (0.28 vs. 0.14 day⁻¹), indicating faster crumb firming despite the observed molecular-level stability. Overall, the results demonstrated that CF contributes to enhanced molecular organization of starch and increased nutritional value of GFB, while its technological performance at the macroscopic level remains formulation-dependent. These findings highlight the need for targeted formulation and process optimization to balance molecular stability with desirable textural properties in CFB.

This study aimed to optimize the formulation of gluten-free bread (GFB) based on rice flour (RF) and Quercus rotundifolia acorn flour (AF) by evaluating the combined effects of flour substitution (0%, 50%, and 100%) and water addition (90%, 100%, and 110%) on technological, textural, colorimetric, structural, and sensory properties. A three-level full factorial design (3²) combined with response surface methodology (RSM) was used to model and optimize product quality. The developed models showed high predictive performance (R² = 0.714–0.999; non-significant lack of fit), confirming their suitability for describing complex interactions in gluten-free systems. Water addition was the dominant factor influencing moisture, crumb structure, and textural softness, while AF mainly affected color, structure, and sensory attributes. Increasing acorn content significantly decreased lightness (L*) and increased redness (a*) and darkness index (DI), reflecting higher phenolic compound content and more intense Maillard reactions. Specific volume (1.85–2.41 cm³/g) was maximized at higher hydration levels, especially when combined with intermediate to high acorn substitution, indicating a synergistic interaction between fiber-rich flour and water availability. Texture analysis showed that AF increased hardness and reduced cohesiveness, while water addition significantly improved softness, elasticity, and overall mouthfeel. Image analysis of crumb structure demonstrated that higher hydration promoted larger pore size and porosity, whereas AF increased cell density, resulting in a finer crumb structure under low hydration conditions. Sensory evaluation confirmed that breads with high acorn content were well accepted due to their characteristic nutty flavor. Multi-response desirability optimization yielded an optimal formulation with approximately 83% AF and 108% water, representing the best achievable compromise among the evaluated quality criteria. The results demonstrate that AF can serve as a key functional ingredient in GFB, provided that hydration is carefully adjusted. This study highlights the effectiveness of RSM combined with image-based analysis as a robust approach for developing high-quality gluten-free bakery products.

Acorns (Quercus spp.) have a long history of use in human nutrition and represent an underutilized plant resource with considerable potential for sustainable food systems. In recent years, acorn flour (AF) has attracted scientific interest as an innovative ingredient, particularly in breadmaking, due to its lack of gluten, favorable nutritional profile, and technological functionality. This review summarizes bread made with AF as a sustainable and innovative food product, with particular emphasis on its technological properties, including rheological behavior, sensory attributes, and nutritional profile. To our knowledge, this review is among the first to integrate an analysis of recent technological advancements in breadmaking with the current European Union regulatory framework, specifically EU Organic Regulation 2018/848. By bridging the gap between food technology and legislative requirements, the review outlines a comprehensive pathway for the commercialization of acorns as a certified organic resource. It concludes that although acorns have significant potential to enhance food security and sustainability, further standardization and increased consumer awareness are necessary to ensure their successful market integration.

Acorn flours from the six Mediterranean Quercus species (Quercus cerris, Quercus petraea, Quercus robur, Quercus ilex, Quercus pubescens, and Quercus rotundifolia) were systematically fractionated for polyphenols using ultrasonic-assisted extraction with seven solvent systems varying in polarity and composition (water at 20 and 40 min; acetone, ethanol, and methanol at 20% and/or 70% v/v). The total polyphenol content (TPC), non-tannic phenolic content (NTPC), tannin content (TC), antioxidant potential (DPPH, ABTS, and FRAP), and individual phenolic profiles through high-performance liquid chromatography (HPLC) were determined. The results showed that the botanical species primarily determined the TPC and TC, while the solvent composition significantly influenced the NTPC yield. Q. cerris yielded the highest average TPC (105.1 ± 3.8 mg GAE/g) and TC, supported by a gallotannin-dominated profile. Conversely, Q. rotundifolia exhibited the lowest values but the highest NTPC/TPC ratio (32.0%). Q. ilex featured species-exclusive ellagitannins, while Q. pubescens showed the highest specific antioxidant activity. For the targeted recovery, 20% acetone is recommended for tannins and 70% ethanol for the non-tannic fractions. These findings establish a species-resolved framework for valorizing acorn flours as functional ingredients, identifying high-tannin species requiring detannification and “sweet” varieties suitable for direct food application.

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.