Isomerization and degradation of all-trans-β-carotene during in-vitro digestion

High internal phase emulsions stabilized by fluorescent phycocyanin for improved stability and bioaccessibility of β-carotene

BACKGROUND

High internal phase emulsions (HIPE) are distinguished from ordinary emulsions by higher oil-phase percentage and better storage stability. Recently, HIPE stabilized with protein-based particles has received more attention. However, organic precipitation, chemical cross-linking and thermal denaturation are often needed to stabilize emulsions with natural proteins, and there is an urgent need to reduce the pollution of organic reagents.

RESULTS

HIPE loaded with β-carotene stabilized by phycocyanin was prepared under mild conditions. It demonstrated strong stability in terms of temperature and storage, as evidenced by its 94.17% retention rate and 81.06% bioavailability. This stability was ascribed to the efficient defense against heat and UV rays, which was probably associated with the oil-droplet environment and interfacial protection of phycocyanin. It is speculated that the possible main interaction site between phycocyanin and sorbitol exists near amino acids 110 to 120 of the B chain. The hydrogen bond and hydrophobic interaction between them make the phycocyanin fully adsorbed on the oil-water interface when sorbitol is stable, forming a strong oil-water structure, which increases the stability of the emulsion.

CONCLUSION

The outstanding fluorescence characteristics provide a feasible alternative for fluorescent emulsions to distribute and trace active compounds in vitro. HIPE loaded with β-carotene might have potential as a 3D printing material for edible functional foods. © 2024 Society of Chemical Industry.

Unveiling fucoxanthin's fate: In vitro gastrointestinal digestion effects on bioaccessibility, antioxidant potential, colour changes, and metabolite profiles

Limited knowledge of fucoxanthin's changes during digestion necessitates comprehensive investigation to ensure its efficacy as a functional ingredient. This study assessed the effects of digestion on fucoxanthin's bioaccessibility, antioxidant activity, colour changes, and metabolite formation through in vitro gastrointestinal digestion. Results indicated the highest bioaccessibility during gastric digestion (0.03 ± 0.00 mg/mL), followed by intestinal and mouth with 0.012 ± 0.00 and 0.011 ± 0.13 mg/mL, respectively. Antioxidant activity was the highest at the gastric stage, with significant activity persisting post-digestion (P < 0.05). Colour changes were significant, with total colour differences (∆E*) of 2.40, 2.86, and 2.76 at the mouth, gastric, and intestinal stages, respectively. LC-MS/MS-based metabolomics analysis revealed 15 key metabolites, with carboxylic acids as major metabolites during gastric and intestinal stages. Pearson correlation analysis demonstrated a significant correlation between identified metabolites with bioaccessibility, antioxidant activity, and colour changes, underscoring fucoxanthin's potential as a promising functional food ingredient.

Taylor dispersion analysis and release studies of β-carotene-loaded PLGA nanoparticles and liposomes in simulated gastrointestinal fluids

β-Carotene (βC), a natural carotenoid, is the most important and effective vitamin A precursor, known also for its antioxidant properties. However, its poor water solubility, chemical instability, and low bioavailability limit its effectiveness as an orally delivered functional nutrient. Nanoparticle encapsulation improves βC's bioaccessibility by enhancing its stability and solubility. This study compares two formulations, i.e. βC-loaded poly(lactic-co-glycolic acid) (PLGA) NPs and liposomes before and after exposure to simulated gastrointestinal fluids using various methods such as Taylor dispersion analysis (TDA), cryo-transmission electron microscopy, dynamic light scattering (DLS), and nanoparticle tracking analysis (NTA). TDA, a microfluidic technique, proved more effective than DLS and NTA in determining nanoparticle size in simulated gastrointestinal fluids. This highlights TDA's potential for assessing nanoparticle colloidal stability in simulated gastro-intestinal fluids, crucial for evaluating encapsulated bioactives' bioavailability. High-performance liquid chromatography (HPLC) revealed that PLGA nanoparticles incorporate and preserve βC more effectively during long-term storage compared to liposomes. Adding ascorbic acid significantly reduced degradation in simulated gastrointestinal fluids. Release studies showed that liposomes released 52% of βC after 36 hours, while PLGA nanoparticles released only 9% over 168 hours. These results provide valuable insights for selecting an appropriate βC nanocarrier for oral delivery based on desired release rates.

Evaluation of astaxanthin stability under varying temperatures and ultraviolet irradiation durations based on Raman spectroscopy

As a potent naturally carotenoid, Astaxanthin (AST) is commonly used as a natural coloring agent and antioxidant in food products, and it's stability is of great interest. The stability of AST solution stored in glass bottle under different temperatures and ultraviolet (UV) irradiation durations was analyzed in situ using confocal Raman spectroscopy, and the acceptable depth of focus was optimized. Raman spectra of AST geometrical isomers were determined by density functional theory (DFT) simulation, and characteristic peaks were selected for studying AST degradation and isomerization. Raman spectra and peak-fitting spectra based on gaussian multi-peak fitting analysis combined with Pearson's correlation analysis were conducted to study the effect of temperatures and UV irradiation on AST degradation and isomerization. The peak intensity ratio of I1518/I880 had been selected as the optimal Raman spectral variable for AST degradation based on Pearson's correlation analysis. Finally, degradation kinetic curves and degradation rate prediction equation were established. The results indicated that the isomerization of 9,13-di-cis isomer occurred at a UV irradiation of 288 h. Moreover, high temperatures above 60 °C and prolonged UV exposure exceeds 48 h can cause significant degradation of AST, with a degradation rate above 20 %. This study provided an in-situ, nondestructive potential method for the calculation of AST degradation under different temperatures and UV irradiation durations, which contribute guiding insights into the development and utilization of AST in food industry.

Pretreatment with Liposome-Encapsulated Shrimp Shell Extract Attenuated Neuronal Damage and Death in Aβ1-42-Induced Memory Deficits in Rats

The accumulation of amyloid-beta (Aβ) peptides is a crucial factor in the neuronal degeneration of Alzheimer's disease (AD). The current study investigated the underlying neuroprotective mechanisms of shrimp shell extract (SSE) and liposome-encapsulated SSE (SSE/L) against Aβ1-42-induced neuronal damage and death in rats. Intracerebroventricular infusion of Aβ1-42 effectively induced memory decline, as observed in a reduction of the rat's discriminating ability in the novel object recognition and novel object location tasks. Oral pretreatment with 100 mg/kg of SSE demonstrated no preventive effect on the memory decline induced by Aβ1-42 infusion. However, treatment with SSE/L 100 mg/kg BW effectively attenuated memory deficits in both behavioral assessments following two and four weeks after Aβ1-42 infusion. Moreover, SSE/L exerted neuroprotective effects by reducing lipid peroxidation and increasing Nrf2/HO-1 expression. There was a significant decrease in Iba1 and GFAP (biomarkers of microglia and astrocyte activity, respectively), as well as a decrease in the levels of NF-κB expression and the inflammatory cytokines TNF-α and IL-6 in the cortical and hippocampal tissues. Treatment with SSE/L also reduced the pro-apoptotic proteins Bax and cleaved caspase-3 while raising the anti-apoptotic protein Bcl2. In addition, the beneficial effects of SSE/L were along with the effects of a positive control commercial astaxanthin (AST). The findings of this study indicated that SSE/L provided neuroprotective effects on Aβ1-42-induced AD rats by ameliorating oxidative stress, neuroinflammation and apoptotic cell death. Therefore, SSE/L might be employed to prevent and mitigate Aβ accumulation-induced neurotoxicity in AD.

Current applications of solid lipid nanoparticles and nanostructured lipid carriers as vehicles in oral delivery systems for antioxidant nutraceuticals: A review

Antioxidant nutraceuticals can be found in several dietary sources and have been utilized for various medical benefits including health promotion, disease prevention, and support for treatment of acute and/or chronic diseases. Nonetheless, there are some limitations in delivering antioxidants via oral administration such as low solubility and permeability, pH and enzyme degradation, and instability of the compounds along the gastrointestinal tract leading to low bioavailability. In order to tackle these challenges, the utilization of lipid nanoparticles has numerous advantages to the escalating delivery system of antioxidants in nutraceuticals across the gastrointestinal tract barrier. Nowadays, several types of lipid nanoparticles can be used in antioxidant nutraceutical delivery systems through the oral route, namely solid lipid nanoparticles and nanostructured lipid carriers. This review article aims to provide notable information on the importance and applications of lipid nanoparticles in antioxidant delivery systems from nutraceuticals by an oral route. The mechanism in enhancing antioxidant compound transport across the gastrointestinal tract can occur by elevating loading capacity, improving chemical and physical stability, and increasing its bioavailability. To date, lipid nanoparticle vehicles have been developed to improve the delivery of antioxidant compounds to enhance bioavailability via oral routes. Lipid nanoparticles have remarkable benefits in delivering antioxidant nutraceuticals via oral administration. Hence, scale-up and commercialization of antioxidant nutraceutical-loaded lipid nanoparticles have been a potential technology in recent years. Subsequently, several vegetable and natural oils with antioxidant activity can also be utilized for nanoparticle formulation lipid components to increase nutraceuticals' antioxidant properties and bioavailability.