Bioaccessibility, Intestinal Absorption and Anti-Inflammatory Activity of Curcuminoids Incorporated in Avocado, Sunflower, and Linseed Beeswax Oleogels.

Beeswax oleogels (OGs), with a mechanical strength similar to pork backfat, were formulated with avocado (A), sunflower (S), and linseed (L) oils, applying a central composite design plus star point, and were evaluated as oral delivery vehicles of curcuminoids (OGACur, OGSCur, OGLCur). The incorporation of curcumin into the OG matrix significantly delayed both the formation of peroxides and conjugated trienes (K268 values), and the degradation rate of curcumin decreased with the increase of the oil polyunsaturated fatty acids (PUFA) content. The oil structuring did not affect the bioaccessibility of curcuminoids (>55% in all the OGs, regardless of the oil type), but it did reduce the release of fatty acids (~10%) during in vitro gastrointestinal digestion. The intestinal absorption, evaluated in Caco-2 cell monolayers, was higher for the micelle-solubilized curcumin from the digested OG than from unstructured oils, and it showed high anti-inflammatory potential by inhibiting the tumor necrosis factor-α (TNF-α) production compared to the positive control, both before and after the stimulation of ThP-1 cells with LPS. Regardless of the oil type, these beeswax-based OGs with gel-like behavior designed as fat replacers may be promising vehicles for the oral delivery of curcuminoids.

Characterization, Bioactivity and Application of Chitosan-Based Nanoparticles in a Food Emulsion Model.

In this study, chitosan nanoparticles (CNPs) were prepared by the ionic gelation technique with tripolyphosphate (TPP), and the effect of CNP composition and physicochemical characteristics were evaluated. After the synthesis optimization, CNPs were used as carriers for a fish protein hydrolysate (FPH) with bioactive properties (CNPH). The physicochemical characteristics, antioxidant capacity and antimicrobial, antihypertensive and emulsifier properties of unloaded and loaded CNPs in a food system model were studied. CNPH showed a uniform particle distribution, size ~200 nm, high stability (zeta potential around 30 mV), radical scavenging activity and increased antimicrobial activity against Staphylococcus aureus, Shigella sonnei and Aeromonas hydrophila. Additionally, CNPH showed an angiotensin I-converting enzyme (ACE)-inhibitory activity of 63.6% and, when added to a food emulsion model, this system containing CNPs, with or without FHP, exhibited improved food emulsion stability. Thus, CNPs were able to carry the FPH while maintaining their bioactive properties and can be an alternative to the delivery of bioactive peptides with potential as an emulsion stabilizer for food applications.

Entrapment of natural compounds in spray-dried and heat-dried iota-carrageenan matrices as functional ingredients in surimi gels.

Two drying methods (spray drying and heat drying) were used to entrap various natural compounds within a matrix of iota-carrageenan. The natural compounds were, namely, collagen hydrolysate (CH), pomegranate polyphenolic extract (PP) and shrimp lipid extract (SL). The resulting dry powders were compared in terms of water solubility, entrapment efficiency, hydrodynamic particle properties, ζ potential and antioxidant properties (ABTS radical scavenging capacity, ferric ion reducing power and Folin-reactive substances). Dry powders and plain compounds were incorporated into squid surimi gels, and after in vitro simulated gastrointestinal digestion (sGID), the residual antioxidant and angiotensin-converting enzyme (ACE)-inhibitory activities were evaluated. All powders showed antioxidant properties, electronegative ζ potential and great entrapment efficiency after rehydration (ranging from ∼70 to 97%). The heat-dried powders were composed of microparticles ranging from 177 to 380 µm resulting in low water solubility (21.6-36.1%), while the average particle size and solubility values of spray-dried preparations were 2.9-13.2 µm and >86%, respectively. In contrast to the plain compounds, the addition of any of the microparticle dried preparations allowed obtaining well-conformed surimi gels. The ACE-inhibitory capacity of the surimi gels after sGID was increased by the addition of any of the compounds studied, but to a lesser extent by their entrapment forms (except with the entrapped SL). The antioxidant activities of gels with the entrapped compounds were even lower than those of gels without bioactives in some cases. In conclusion, the addition of dried microparticles did not increase the biological activity as compared to the plain compounds; however, they were beneficial to ensure adequate gel consistency.

Functional aptitude of hake minces with added TMAO-demethylase inhibitors during frozen storage.

The ability of compounds of natural origin (black, white, red, and green tea extracts, phytic acid) to inhibit TMAO-demethylase enzyme was assayed. Black tea and phytic acid exerted the highest inhibiting activities, similar to the already known inhibitor sodium citrate. Hake minces incorporating these three compounds were prepared and stored frozen (150 days, -12 °C). TMAO-demethylase enzyme was partially inhibited (lower enzyme activity, reduction of formaldehyde accumulation). The study of physicochemical properties of the minces (salt-soluble proteins, water holding capacity, structural water associated with myofibrils) pointed to evident protein aggregation and loss of functionality when phytic acid was added, whereas black tea and sodium citrate did not have a negative effect. Consequently, the salt-ground mince with phytic acid showed worse viscoelastic properties than the others. In conclusion, black tea polyphenols and sodium citrate can be used as additives to inhibit TMAO-demethylase enzyme during frozen storage of fish minces.

Bioaccessibility and antimicrobial properties of a shrimp demineralization extract blended with chitosan as wrapping material in ready-to-eat raw salmon.

A shrimp extract (SME) obtained from the mild-acid demineralization treatment of shrimp shells to produce chitosan was collected. It was mainly composed of fat (≈73%), protein (≈19%), and ash (≈9%) and contained considerable amounts of calcium (≈1.9 g/100 g), astaxanthin (≈30 mg/100 g) and unsaturated fatty acids (≈27% MUFA, ≈39% PUFA). The SME was used in combination with chitosan for wrapping raw salmon to produce a ready-to-eat product enriched in calcium. No significant changes in hardness were found, as compared to the unwrapped salmon. Estimated intakes of bioaccessible calcium increased significantly by 3.6-fold, whereas intake of bioaccessible fat was reduced by 15%. SFA were the main fatty acid group reduced (≈80%), whereas MUFA and PUFA were only reduced by ≈20% each. Total viable counts, pseudomonads, enterobacteria, and specific fish spoilers were reduced by 2-4 log CFU/g in wrapped sample during the chilled storage period (19 days).

Chemical characterization of wash water biomass from shrimp surimi processing and its application to develop functional edible films.

The aim of this work was to recover and study the composition of the biomass obtained from the surimi processing industry, and to explore the feasibility of its valorization by developing functional edible films. A concentrate from wash water of minced shrimp muscle of low commercial value [shrimp concentrate (SC)] was obtained by alkaline solubilization and isoelectric precipitation, which had protein content of 61.8% and fat 23.6%. The protein fraction of low molecular weight (≤37 kDa), with maximum solubility at basic pH 9-11, and was rich in essential amino acids (296 essential amino acids/1000 residues), whereas the fat fraction showed a high degree of unsaturation (26.8% MUFA, 28.3% PUFA). SC, showed antioxidant activity measured by FRAP and ABTS assays and, was successfully incorporated into an agar film matrix (agar-to-protein ratio of 3:1). The films were translucent and brownish and maintained integrity upon immersion in water, but swelled considerably. Films were able to release protein and exert antioxidant activity in water and 95% ethanol (aqueous and fatty food simulants, respectively), the release being faster and greater in the former. In conclusion, the biomass obtained from shrimp mince/surimi processing was for developing edible films.

Recovery, viscoelastic and functional properties of Barbel skin gelatine: investigation of anti-DPP-IV and anti-prolyl endopeptidase activities of generated gelatine polypeptides.

The characteristics and functional properties of gelatine from freshwater fish skin (Barbus callensis) were investigated. The gelatine extraction efficiency was improved by an acid-swelling process in the presence of barbel crude acid protease extract. Barbel skin gelatine (BSG) contained 92.15% protein, 0.31% lipid and 0.72% ash. The amino acid profile of BSG showed a high percentage of imino acids. The electrophoretic profile showed that BSG is mainly composed of α- and ß-components. BSG showed an excellent solubility and possessed interfacial properties, which were governed by the protein concentration. Biological activities of the hydrolysates obtained after digestion of BSG with several commercial proteases were evaluated. The results suggested that these hydrolysates are a good source of natural inhibitors of dipeptidyl peptidase-IV and prolyl endopeptidase and could potentially be used as dietary ingredients in the management of type 2-diabetes and/or neuropathological disorders.

Nanoencapsulation of an active peptidic fraction from sea bream scales collagen.

Sea bream scales were subjected to enzymatic hydrolysis with Esperase, and a peptide fraction with a molecular mass <3kDa (F3) was isolated by ultrafiltration. F3 was encapsulated in nanoliposomes made of partially purified phosphatidylcholine (PC). Concentrations of 3.1% and 1mg/ml for PC and F3, respectively, were established as the best entrapment protocol by response surface methodology. The liposomes entrapment efficiency and zeta potential were 74.6±0.9% and -40.8±0.67mV, respectively. The liposome size ranged from 66.2 to 214nm, with a mean diameter of 90.3nm and a polydispersity index of 0.25. The antioxidant activity and ACE inhibitory activity of the encapsulated peptide fraction (L-F3) remained constant after 8days at 4°C. Encapsulation preserved the biological activities of F3, and could therefore be an alternative to improve the stability of these compounds when applied to a food product.

The effect of combined traditional and novel treatments on oxidative status of dolphinfish (Coryphaena hippurus) and sardine (Sardina pilchardus) muscle lipids.

Fish is rich in polyunsaturated fatty acids with beneficial effects on human health; however, these lipids are very sensitive to auto-oxidation reactions, leading to loss of nutritional and sensory quality. The effect of traditional (brining, smoking) and novel (addition of polyphenolic extracts, high pressure) preservation processes on the antioxidant/oxidative status of muscle lipids from dolphinfish and sardine was studied. Brining with oregano or rosemary aqueous extracts, as well as smoking, gave rise to deposition of phenolic compounds (9-42, 1.5-4.5 and 0.4-2.3 µg phenol/g for smoked, oregano-brined and rosemary-brined samples, respectively) in the muscle of both fish species. The antioxidant activity, as measured by ferric reducing ability, was also improved after brining with antioxidant extracts or smoking, results ranging from 8.9 to 82 mM FeSO4 · 7H2O equivalents/mg muscle depending on the treatment and the fish species. Consequently, fish lipid oxidation (as measured by thiobarbituric acid reactive substances) derived from brining and pressurizing, applied alone or in combination, was reduced between 6.6 and 69.8% depending on the treatment and the fish species. The combination of brining with oregano extract and light smoking showed an additional antioxidant effect, as compared with that obtained by smoking, on reducing sardine lipid oxidation derived from brining and pressurizing.