Susana Cofrades

Carob-based bigels (BGs) were developed as structured fat replacers and delivery systems for bioactive compounds during gastrointestinal digestion. Four formulations combining different hydrogel (HG)/oleogel (OG) ratios and selective incorporation of two carob extracts—an inositol-rich extract (I-CFE) in the HG phase and a phenolic-rich extract (P-CFE) in the OG phase—were evaluated to determine the influence of microstructure on digestive behavior and bioactive release. Confocal microscopy showed that BG structure was mainly governed by the OG network, while alginate-rich aqueous domains remained dispersed and confined to different extents depending on formulation. This organization strongly influenced hydration, enzyme accessibility and matrix breakdown during digestion. D-Pinitol remained stable throughout gastrointestinal digestion, and its release depended on the accessibility of hydrated aqueous domains. Phenolic release and antioxidant activity were also modulated by matrix architecture and extract localization, with BG-70/30-I+P showing the most efficient and sustained antioxidant response. Lipid digestion and fatty acid bioaccessibility were similarly influenced by BG structure: less compact OG networks promoted greater lipase accessibility and higher bioaccessibility of unsaturated fatty acids, whereas more structured lipid matrices partially restricted lipolysis. Overall, BG functionality was governed primarily by microstructural organization rather than composition alone.

Bigels (BGs) were formulated using gelatin (GA) or gellan gum (GG) hydrogels (HGs) combined with beeswax-structured oleogels (OGs). Carob fruit extracts—an inositol-rich fraction (I-CFE) and a polyphenol-rich fraction (P-CFE)—were incorporated into the HG and OG phases, respectively, to enable dual delivery. The effects of composition on rheological, textural, thermal, color, and stability properties were evaluated at HG/OG ratios of 70/30, 60/40, and 50/50. GG-based BGs formed rigid, coherent, and crystal-reinforced networks, exhibiting the highest oscillatory stiffness and complex viscosity. GA-based BGs developed softer, more deformable, and viscous structures, with mechanical behavior strongly governed by damping and water content. Increasing OG content reinforced GG BGs through beeswax–crystal integration, whereas in GA it increased oscillatory stiffness but weakened the cohesive, viscous, and recoverable characteristics of the protein network. Categorical principal component analysis (CATPCA) revealed two mechanical domains: a GA-associated regime dominated by viscosity, penetration resistance, and loss factor (tan δ), and a GG-associated regime governed by elastic stiffness. Correlations confirmed tan δ_max as a marker of structural fragility in GA, while stiffness parameters dominated GG behavior. Melting points remained within 53–54 °C, and all BGs showed excellent physical stability. Overall, GA and GG provide complementary design spaces, offering a mechanistic basis for the rational design of BGs with controlled structural and functional properties.

This study evaluates a non-invasive and feasible nutritional strategy as a realistic intervention to prevent or mitigate T2DM in one-year-old female Wistar rats. This strategy is based on replacing a commercial pâté (CP) with a functional one, either a silicon-enriched commercial pâté (Si-CP), a reduced-fat pâté formulated with a biopolymeric emulsion (BP), or a silicon-enriched and reduced-fat biopolymeric pâté (Si-BP). After consumption of a high-saturated fat high-cholesterol diet, CP rats exhibited elevated fecal excretion, fasting serum glucose, insulin, and LDL cholesterol, and altered islet morphology. Versus the CP group, the Si-CP consumption group exhibited significantly reduced fecal output (1.17 ± 0.02 vs. 2.09 ± 0.44) and serum insulin (12.06 ± 7.89 vs. 20.74 ± 7.44), triglycerides (47.51 ± 4.46 vs. 58.24 ± 9.97), LDL cholesterol (34.63 ± 5.14 vs. 42.20 ± 4.98), and ghrelin (32.49 ± 24.66 vs. 78.35 ± 22.85). Although BP rats also exhibited some positive effects, Si-BP animals presented the most promising results. Compared to the CP group, Si-BP consumption significantly reduced fecal excretion (1.44 ± 0.24) and serum glucose (129.1 ± 10.40 vs. 154.9 ± 15.76), insulin (9.49 ± 6.06), triglycerides (46.91 ± 5.13), and estradiol (528.2 ± 45.00 vs. 634.4 ± 98.87), preserved islet circularity (0.88 ± 0.02 vs. 0.82 ± 0.01), and significantly increased tibia length (4.09 ± 0.12 vs. 3.95 ± 0.09) and wet weight (0.65 ± 0.07 vs. 0.56 ± 0.06). This study demonstrates the antidiabetic effects of silicon from diatomaceous earth (4 mg Si/kg body/day) incorporated into pâté in middle-aged female rats. Replacing CP with a functional alternative improved the health status of diabetic female rats, supporting its potential as an effective nutritional adjuvant.

This study explores the development of bigels (BGs) combining a hydrophilic hydrogel (HG) and a lipophilic oleogel (OG) for co-delivery of two carob fruit extracts (CFEs): I-CFE (inositols) and P-CFE (phenolics). The BGs were formulated in HG:OG ratios of 70:30 and 30:70, using a sodium alginate-based HG and an OG composed of olive pomace oil (OPO) and microcrystalline wax (MW). CFEs were loaded in three modes: I-CFE in HG, P-CFE in OG, and both in their respective phases. Rheological, thermal, physicochemical, and microstructural properties were assessed. All the BGs exhibited solid-like viscoelastic behavior, with greater rigidity in 30:70 formulations. The OG phase enhanced the structural BG network, especially when loaded with P-CFE. At 70:30, I-CFE conferred pseudoplasticity and conformational flexibility, particularly in the absence of P-CFE. At 30:70, both extracts acted synergistically, increasing mechanical strength and network organization. Thermal analysis confirmed MW’s role in structuration, with the BGs showing melting peaks between 40–50 °C. The effects studied affected color and stability. Polarized light microscopy confirmed organized microstructures. This is the first work demonstrating the structuring potential and interactive effects of dual carob extracts (I-CFE and P-CFE) within BGs. All the BGs showed suitable fat-replacer properties, remaining self-standing for 21 days, except the 70:30 I-CFE-free formulation. The findings highlight the potential of CFE-loaded BGs as multifunctional fat replacers in healthier meat products.

The use of silicon (Si) in functional foods is innovative.

This study examines the effects of an emulsion gel (EG) and a fat bulking agent (BA), both formulated with pork lard (PL) and an alginate-based gelling system, as animal fat replacers in the reformulation of reduced-fat fresh pork sausages. Both fat analogs were characterized in terms of texture, color, and in vitro gastrointestinal digestion (GID) before being used in the reformulation of four fresh pork sausages, without and with added silicon (Si) from diatomaceous earth powder: S/EG, S/EG-Si, S/BA, and S/BA-Si. Reduced-fat sausages elaborated exclusively with pork backfat (PB), without and with Si, were used as controls (S/C and S/C-Si). Both EG and BA showed adequate physicochemical characteristics and slowed in vitro GID compared to PL and PB. Replacing 75% PB with EG or BA did not negatively impact the technological, nutritional, or sensory properties of the reformulated pork sausages, which were kept for 14 days under refrigeration. Additionally, sausages containing EG or BA as fat substitutes presented lower lipid digestibility after in vitro digestion compared to the control samples. The addition of Si further limited fat digestion, as reflected by the lower release of free fatty acids after in vitro GID compared to products without added Si. This effect was more pronounced in EG-based formulations. Therefore, the use of EG as a PB replacer, together with the addition of Si, could become a promising strategy for developing healthier meat products. This finding may have important implications for the development of functional meat products aimed at reducing fat content and lipid absorption, thereby laying the foundation for precision nutrition strategies focused on improving individual health outcomes.

This study examines the effect of an emulsion gel (EG) and a fat bulking agent (BA), both formulated with pork lard (PL) and an alginate-based gelling system, as animal fat replacers in the reformulation of reduced-fat fresh pork sausages. Both fat analogues were characterized in terms of texture, color and in vitro gastrointestinal digestion (GID) before being used in the reformulation of four fresh pork sausages, without and with added silicon (Si) from diatomaceous earth powder: S/EG, S/EG-Si, S/BA and S/BA-Si. Reduced-fat sausages elaborated exclusively with pork backfat (PB), without and with Si, were used as controls (S/C and S/C-Si). Both EG and BA showed adequate physicochemical characteristics and slowed in vitro GID compared to PL and PB. Replacing 75% PB with EG or BA did not negatively impact the technological, nutritional or sensory properties of the reformulated pork sausages, which were kept for 14 days under refrigeration. Additionally, sausages containing EG or BA as fat substitutes presented lower lipid digestibility after in vitro digestion compared to the control samples. The addition of Si further limited fat digestion, as reflected by the lower release of free fatty acids after in vitro GID compared to products without added Si. This effect was more pronounced in EG-based formulations. Therefore, the use of EG as PB replacer together with the addition of Si could become a promising strategy for developing healthier meat products.

Developing puff pastry (PP) laminating fats (LFs) with sustainable structured olive pomace oil (OPO) could contribute to its increased valorization. This study evaluated the physicochemical stability of four OPO-based LFs or margarines and the performance of their baked PP counterparts during two months of chilling storage at 4 °C. LF samples, developed at the laboratory scale, contained 41% (LF1 and LF2) OPO and 31% (LF3 and LF4) OPO together with 10% cocoa butter when using two static initial crystallization conditions (room temperature for LF1 and LF3, freezer for LF2 and LF4) before storage. During the storage period, the proximate composition, thermal and dynamic rheological properties, firmness and spreadability, oil-binding capacity, color, and lipid oxidation of the four LF samples were examined, along with the baking performance and textural properties of the PP counterparts. The initial cooling rate had minimal significance. Cocoa butter negatively influenced post-crystallization processes occurring in OPO-based LF3 and LF4, resulting in increased hardness and reduced performance after 18 days of storage, attributed, at least partially, to a high amount of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP), mainly from cocoa butter. Conversely, OPO-based LF1 and LF2 maintained their quality and were stable for two months without apparent granular crystal formation.

Oleogels (OG) and gelled emulsions (GE) were elaborated with a mixture of olive and chia oils (80:20 ratio) without and with the incorporation of the health-related compound curcumin. These were studied to evaluate the influence of the oil structuring system on the lipid hydrolysis and bioaccessibility of three healthy fatty acids (FA) (palmitic, oleic, and α-linolenic acids) and of curcumin, compared to the oil mixture (bulk oil, BO). The oil structuring system influenced the firmness and texture, and the presence of curcumin significantly altered the color parameters. GE showed higher lipid digestibility, with a greater proportion of absorbable fraction (higher content of free FA and monoacylglycerides) than OG, which behaved similarly to BO. The presence of curcumin affected the degree of lipolysis, reducing lipid digestibility in OG and increasing it in GE. As for FA bioaccessibility, although GE presented higher percentages overall, curcumin significantly increased and decreased FA bioaccessibility in OG and GE, respectively. The oil structuring system also influenced the bioaccessibility of curcumin, which was higher in GE. Therefore, when selecting an oil structuring system, their physicochemical properties, the degree of lipid hydrolysis, and the bioaccessibility of both curcumin and the FA studied should all be considered.