Unlocking the health potential of anthocyanins: a structural insight into their varied biological effects.

Anthocyanins have become increasingly important to the food industry due to their colorant features and many health-promoting activities. Numerous studies have linked anthocyanins to antioxidant, anti-inflammatory, anticarcinogenic properties, as well as protection against heart disease, certain types of cancer, and a reduced risk of diabetes and cognitive disorders. Anthocyanins from various foods may exhibit distinct biological and health-promoting activities owing to their structural diversity. In this review, we have collected and tabulated the key information from various recent published studies focusing on investigating the chemical structure effect of anthocyanins on their stability, antioxidant activities, in vivo fate, and changes in the gut microbiome. This information should be valuable in comprehending the connection between the molecular structure and biological function of anthocyanins, with the potential to enhance their application as both colorants and functional compounds in the food industry.

Effects of frying on the surface oil absorption of wheat, potato, and pea starches.

The effects of structural changes on surface oil absorption characteristics of wheat starch, pea starch and potato starch during frying under different water content (20%, 30%, 40%, 50%) were studied. Fried potato starch with a 40% water content exhibited the highest surface oil content. When the initial moisture content reached 30%, the scattering intensity of the crystal layer structure decreased for wheat and pea starches, while the scattering peak for potato starch completely disappeared. At 40% moisture content, the amorphous phase ratio values for fried potato, wheat and pea starches were 13.50%, 11.78% and 11.24%, respectively, and the nitrogen adsorption capacity of fried starch decreased in turn. These findings that the structure of potato starch was more susceptible to degradation compared to pea starch and wheat starch, resulting in higher surface oil absorbed by potato starch during frying process.

PA-Net: A phase attention network fusing venous and arterial phase features of CT images for liver tumor segmentation.

BACKGROUND AND OBJECTIVE: Liver cancer seriously threatens human health. In clinical diagnosis, contrast-enhanced computed tomography (CECT) images provide important supplementary information for accurate liver tumor segmentation. However, most of the existing methods of liver tumor automatic segmentation focus only on single-phase image features. And the existing multi-modal methods have limited segmentation effect due to the redundancy of fusion features. In addition, the spatial misalignment of multi-phase images causes feature interference. METHODS: In this paper, we propose a phase attention network (PA-Net) to adequately aggregate multi-phase information of CT images and improve segmentation performance for liver tumors. Specifically, we design a PA module to generate attention weight maps voxel by voxel to efficiently fuse multi-phase CT images features to avoid feature redundancy. In order to solve the problem of feature interference in the multi-phase image segmentation task, we design a new learning strategy and prove its effectiveness experimentally. RESULTS: We conduct comparative experiments on the in-house clinical dataset and achieve the SOTA segmentation performance on multi-phase methods. In addition, our method has improved the mean dice score by 3.3% compared with the single-phase method based on nnUNet, and our learning strategy has improved the mean dice score by 1.51% compared with the ML strategy. CONCLUSION: The experimental results show that our method is superior to the existing multi-phase liver tumor segmentation method, and provides a scheme for dealing with missing modalities in multi-modal tasks. In addition, our proposed learning strategy makes more effective use of arterial phase image information and is proven to be the most effective in liver tumor segmentation tasks using thick-layer CT images. The source code is released on (https://github.com/Houjunfeng203934/PA-Net).

Impact of pesticide polarity and lipid phase dimensions on the bioaccessibility of pesticides in agricultural produce consumed with model fatty foods.

For most people, the pesticide residues found on agriculture products are the main source of pesticide exposure, which may adversely influence consumer health. The potential health hazard of residual pesticides depends on the nature of the foods they are consumed with. Studies with fat-soluble vitamins and nutraceuticals have shown that their bioaccessibility depends on food matrix composition and structure. We used an in vitro method to investigate the influence of the dimensions of the lipid phase in model fatty foods (emulsified or bulk oil) on the bioaccessibility of various pesticides. Three pesticides that differed in their oil-water partition coefficients were selected: bendiocarb (log P = 1.7), parathion (log P = 3.8), and chlorpyrifos (log P = 5.3). These pesticides were mixed with tomato puree to represent pesticide-treated agricultural products. Three model foods with different oil phase dimensions were used to represent different kinds of food product: small emulsions (d32 = 0.14 µm); large emulsions (d32 = 10 µm); and, bulk oil. Our results showed that the oil droplets underwent extensive changes as they passed through the simulated gastrointestinal tract due to changes in environmental conditions, such as pH, ionic strength, bile salts, and enzyme activities. The initial rate and final amount of lipid hydrolysis decreased with increasing lipid phase dimensions. Pesticide bioaccessibility depended on both the hydrophobicity of the pesticide and the dimensions of the co-ingested lipid droplets. The least hydrophobic pesticide (bendiocarb) had a high bioaccessibility (>95%) that did not depend on lipid phase dimensions. The more hydrophobic pesticides (parathion and chlorpyrifos) has a lower bioaccessibility that increased with decreasing lipid phase dimensions. Our results demonstrate the critical role that food structure plays on the potential uptake of pesticides from agricultural products, like fruits and vegetables.

Impact of Pesticide Type and Emulsion Fat Content on the Bioaccessibility of Pesticides in Natural Products.

There is interest in incorporating nanoemulsions into certain foods and beverages, including dips, dressings, drinks, spreads, and sauces, due to their potentially beneficial attributes. In particular, excipient nanoemulsions can enhance the bioavailability of nutraceuticals in fruit- and vegetable-containing products consumed with them. There is, however, potential for them to also raise the bioavailability of undesirable substances found in these products, such as pesticides. In this research, we studied the impact of excipient nanoemulsions on the bioaccessibility of pesticide-treated tomatoes. We hypothesized that the propensity for nanoemulsions to raise pesticide bioaccessibility would depend on the polarity of the pesticide molecules. Bendiocarb, parathion, and chlorpyrifos were therefore selected because they have Log P values of 1.7, 3.8, and 5.3, respectively. Nanoemulsions with different oil contents (0%, 4%, and 8%) were fabricated to study their impact on pesticide uptake. In the absence of oil, the bioaccessibility increased with increasing pesticide polarity (decreasing Log P): bendiocarb (92.9%) > parathion (16.4%) > chlorpyrifos (2.8%). Bendiocarb bioaccessibility did not depend on the oil content of the nanoemulsions, which was attributed to its relatively high water-solubility. Conversely, the bioaccessibility of the more hydrophobic pesticides (parathion and chlorpyrifos) increased with increasing oil content. For instance, for chlorpyrifos, the bioaccessibility was 2.8%, 47.0%, and 70.7% at 0%, 4%, and 8% oil content, respectively. Our findings have repercussions for the utilization of nanoemulsions as excipient foods in products that may have high levels of undesirable non-polar substances, such as pesticides.

Effect of pullulan on oil absorption and structural organization of native maize starch during frying.

The oil-absorption behavior of native maize starch (NMS) during frying was investigated in the presence or absence of pullulan (PUL) using a LF-NMR method. The morphology, long-range order, short-range order, and thermal properties of fried NMS-PUL mixtures were further evaluated using SEM, XRD, ATR-FTIR, and DSC, respectively. Pullulan addition significantly reduced the oil content of the fried starch samples: 0.395, 0.310, 0.274, and 0.257 g/g in NMS with addition of 0, 1, 3, and 5% PUL, respectively (p < 0.05). SEM analysis showed that the intact granular morphology of the starch granules was preserved upon addition of pullulan. The XRD, FTIR, and DSC results showed that pullulan protected both the short-range double helices and long-range crystalline structure of the granules during frying. As a result, fried NMS-PUL mixtures were denser than fried NMS, thus inhibiting oil absorption during frying. These results may have important implications for creating healthier reduced-fat fried food products.

Lotus seedpod proanthocyanidin-whey protein complexes: Impact on physical and chemical stability of ß-carotene-nanoemulsions.

The impact of lotus seedpod proanthocyanidin (LSPC) on the functional properties of ß-carotene-loaded whey-protein stabilized nanoemulsions was investigated. LSPC was selected because it is known to exhibit strong antioxidant activity, as well as having various health benefits. Physically stable nanoemulsions containing small anionic droplets (d < 0.15 µm; ζ = -27 mV) could be formed at pH 6.5 using whey protein-LSPC complexes as natural emulsifiers. The physical and chemical stabilities of the nanoemulsions were then measured when they were incubated at different pH values. LSPC addition promoted droplet aggregation at pH 4, but not at pH 3, 6.5, or 8, which was mainly attributed to its ability to reduce the electrostatic repulsion between the lipid droplets at pH 4. LSPC was shown to have stronger antioxidant activity than catechin and epicatechin. Our results show that the chemical stability of ß-carotene nanoemulsions could be considerably improved by adding LSPC. We believe that LSPC-whey protein complexes can be used as effective emulsifiers and antioxidants in nutraceutical-loaded nanoemulsions, which may be useful for developing more efficacious functional foods and beverages.

Bioaccessibility and stability of ß-carotene encapsulated in plant-based emulsions: impact of emulsifier type and tannic acid.

The effect of two plant-based emulsifiers (quillaja saponin, QS and gum arabic, GA) and a polyphenol (tannic acid) on the formation, stability, digestibility, and ß-carotene (BC) bioaccessibility of flaxseed oil-in-water emulsions was investigated. The gastrointestinal behavior of the emulsions was studied using a simulated gastrointestinal tract (GIT) consisting of mouth, stomach, and small intestine regions. In the absence of tannic acid, the initial extent of lipid digestion depended strongly on emulsifier type, with 45% and 76% of the free fatty acids being released after 5 min digestion for QS- and GA-emulsions, respectively. Even so, the lipid droplets were completely digested in both emulsions after 2 h incubation in the small intestine phase. Tannic acid addition (0.01% and 0.1% w/w) slowed down lipid digestion, but did not impact the final extent. The droplets in the QS-emulsions containing 0.1% tannic acid were highly flocculated in the stomach phase. Molecular docking simulations indicated that the interactions between tannic acid and the saponins were mainly driven by hydrogen bonding and hydrophobic interactions. Moreover, they showed that the interactions between tannic acid and QS were stronger at pH 2.5 than at pH 7.0, which would account for the extensive droplet flocculation observed under acidic conditions in the stomach. Emulsifier type and tannic acid addition had no significant influence on BC bioaccessibility. The GA-emulsions exhibited better stability than the QS-emulsions when stored at elevated temperatures (55 °C for 7 days). Tannic acid addition effectively inhibited temperature-induced BC degradation. These results may facilitate the design of more efficacious nutraceutical-loaded functional foods and beverages.

Formation and characterization of oil-in-water emulsions stabilized by polyphenol-polysaccharide complexes: Tannic acid and ß-glucan.

Oil-in-water emulsions were prepared that were stabilized by a polyphenol (tannic acid, TA) and/or a polysaccharide (ß-glucan, BG). The influence of TA concentration and solution pH on the physical stability and microstructure of the emulsions was investigated. Emulsions formed using only BG (1%) contained large droplets that were unstable to flocculation and coalescence. The stability of the emulsions (pH 5) could be enhanced by optimizing the ratio of TA-to-BG used to form them, i.e., TA/BG = 0.4 or 0.5. This effect was attributed to a combination of increased steric hindrance and reduced hydrogen bonding of TA to BG. Transmission electron microscopy (TEM) indicated that increasing the level of TA present increased the compactness and thickness of the TA-BG interfacial layers formed around the oil droplets. Furthermore, the stability of the emulsions to droplet flocculation and coalescence depended on the TA/BG ratio and solution pH. The impact of environmental conditions on emulsion stability was also investigated. Emulsions stabilized by TA-BG complexes (TA/BG = 0.5) remained stable from pH 5 to 9 at ambient temperature and at temperatures ≤60 °C at pH 5, but were highly unstable to salt addition at pH 5. Our results may increase the breadth of applications of ß-glucan as a functional ingredient in foods.

Fabrication of plant-based vitamin D3-fortified nanoemulsions: influence of carrier oil type on vitamin bioaccessibility.

The influence of carrier oil type (corn, fish, or flaxseed oil) on the production, stability, and simulated gastrointestinal behavior of vitamin-fortified nanoemulsions was studied. The nanoemulsions were formulated using pea protein as an emulsifier since there is increasing interest in substituting artificial and animal-based food ingredients with natural plant-based alternatives. Lipid digestion and vitamin D3 bioaccessibility were measured when the nanoemulsions were subjected to a three-stage in vitro gastrointestinal tract: oral, gastric, and small intestinal. The majority of all three lipids were digested within the first few minutes in the simulated small intestine, with the corn oil nanoemulsions being digested faster than the fish or flaxseed oils. Moreover, a greater fraction of triglycerides were digested by the end of the small intestine for the corn oil than for the fish and flaxseed oils. For the different carrier oils, vitamin bioaccessibility was ranked: corn oil > flaxseed oil ≈ fish oil. These results suggest that monounsaturated-rich oils (such as corn oil) are better for encapsulating and delivering vitamin D3 than polyunsaturated-rich ones (such as flaxseed or fish oil). The insights gained here may aid in the formulation of more efficacious vitamin-fortified foods and beverages from plant-derived ingredients.

Establishing the impact of food matrix effects on the bioaccessibility of nutraceuticals and pesticides using a standardized food model.

It is important to establish the impact of food matrix effects on the bioaccessibility of co-ingested substances, such as nutraceuticals, engineered nanomaterials, pharmaceuticals, and pesticides. Recently, a standardized food model (SFM) representing a typical US diet has been developed to facilitate these investigations. This model consists of caseinate-stabilized fat droplets, free casein, pectin, starch, sucrose, and sodium chloride. The SFM was stable to creaming for 2 days, contained small particles (d ≈ 180 nm), and had a narrow particle size distribution. The SFM was mixed with pureed tomato that had been deliberately contaminated with chlorpyrifos (a hydrophobic pesticide). The resulting mixture was then exposed to an in vitro digestion model. The structural and physicochemical characteristics of the samples (microstructure, particle diameter, and surface potential) were determined after each GIT stage. Also, the bioaccessibility of both chlorpyrifos and lycopene (a hydrophobic nutraceutical) from the pesticide-contaminated tomatoes was determined after the final digestion process. For lycopene, the bioaccessibility was much lower for tomato alone (0.75%) than for tomato plus SFM (19.0%) (p < 0.05). For chlorpyrifos, the bioaccessibility was also appreciably lower for tomato alone (40.4%) than for tomato plus SFM (58.7%), but the effect was less dramatic (p < 0.05). Our results indicate that a standardized food matrix impacts the bioaccessibility of hydrophobic bioactives in fresh produce by an amount that depends on the nature of the bioactive agent. The SFM developed here may therefore be useful for screening the potential impact of food matrix effects on the bioaccessibility of ingested bioactives and other substances.

Vitamin E Encapsulation within Oil-in-Water Emulsions: Impact of Emulsifier Type on Physicochemical Stability and Bioaccessibility.

The influence of plant-based (gum arabic and quillaja saponin) and animal-based (whey protein isolate, WPI) emulsifiers on the production and stability of vitamin E-fortified emulsions was investigated. Their impact on lipid digestibility and vitamin bioaccessibility was also studied utilizing an in vitro gastrointestinal tract. WPI and saponin produced smaller emulsions than gum arabic. All emulsions had good storage stability at room temperature (4 weeks, pH 7). Saponin- and gum arabic-emulsions were resistant to droplet aggregation from pH 2 to 8 because these emulsifiers generated strong electrosteric repulsion. WPI-coated droplets flocculated around pH 5 due to a reduction in charge near their isoelectric point. Lipid digestion was slower in saponin-emulsions, presumably because the high surface activity of saponins inhibited their removal by bile acids and lipase. Vitamin bioaccessibility was higher in WPI- than in saponin- or gum arabic-emulsions. This information may facilitate the design of more efficacious vitamin-fortified delivery systems.

Bioaccessibility and cellular uptake of ß-carotene in emulsion-based delivery systems using scallop (Patinopecten yessoensis) gonad protein isolates: effects of carrier oil.

Emulsion-based delivery systems were structured by using scallop gonad protein isolates (SGPIs) as novel food-grade emulsifiers. The effects of carrier oil, including the long chain triglycerides (LCT) and medium chain triglycerides (MCT), on the bioaccessibility and cellular uptake of ß-carotene (BC) were investigated. Both LCT and MCT delivery systems remained stable at pH 7-8 but aggregated at lower pH values (3-6) according to the results of light scattering and microscopy measurements. LCT droplets fabricated within SGPIs were digested and released more slowly than MCT droplets during the simulated gastrointestinal tract digestion. The LCT emulsion showed higher BC bioaccessibility (65.5%) than the MCT emulsion (23.1%) as a result of the greater solubilization of BC in mixed micelles fabricated from long-chain fatty acids. Moreover, the LCT emulsion produced higher cellular uptake of BC as compared with the MCT emulsion in intestinal epithelial cells. These results demonstrated that SGPIs could be used as novel food-grade emulsifiers to protect lipophilic bioactive compounds in emulsion-based delivery systems, in which LCT is more suitable to encapsulate and deliver BC than MCT.

Design, Fabrication, Characterization, and In Vitro Digestion of Alkaloid-, Catechin-, and Cocoa Extract-Loaded Liposomes.

Liposomes containing theobromine, caffeine, catechin, epicatechin, and a cocoa extract were fabricated using microfluidization and sonication. A high encapsulation efficiency and good physicochemical stability were obtained by sonication (75% amplitude, 7 min). Liposomes produced at pH 5.0 had mean particle diameter ranging from 73.9 to 84.3 nm. The structural and physicochemical properties of the liposomes were characterized by transmission electron microscopy, confocal fluorescence microscopy, and antioxidant activity assays. The release profile was measured by ultra-high performance liquid chromatography coupled to diode array detection. The bioaccessibility of the bioactive compounds encapsulated in liposomes was determined after exposure to a simulated in vitro digestion model. Higher bioaccessibilities were measured for all catechins-loaded liposome formulations as compared to nonencapsulated counterparts. These results demonstrated that liposomes are capable of increasing the bioaccessibility of flavan-3-ols, which may be important for the development of nutraceutical-enriched functional foods.

In Vitro Bioavailability, Cellular Antioxidant Activity, and Cytotoxicity of ß-Carotene-Loaded Emulsions Stabilized by Catechin-Egg White Protein Conjugates.

Previously, it was shown that catechin-egg white protein (CT-EWP) conjugates were effective antioxidant emulsifiers that could form and stabilize emulsions, and also inhibit the degradation of encapsulated carotenoids. The objective of the current study was to evaluate the impact of conjugation on the in vitro bioavailability, cellular antioxidant activity, and cytotoxicity of ß-carotene-loaded emulsions. Lipid droplets coated with EWP or with CT-EWP conjugates exhibited quite similar behavior when they were passed through a simulated gastrointestinal tract. The ß-carotene encapsulated in emulsions stabilized by CT-EWP conjugates exhibited a higher overall in vitro bioavailability, which was attributed to a greater stability of the carotenoids to chemical transformation. The emulsions stabilized by CT-EWP conjugates also exhibited greater ability in inhibiting oxidation in a cell-based assay (dichlorofluorescein diacetate). Cytotoxicity analysis suggested that ß-carotene emulsions stabilized by CT-EWP conjugates only exhibited a slight cytotoxicity when used at high concentrations. These results suggest that CT-EWP conjugates can be used to formulate emulsion-based delivery systems for chemically labile hydrophobic bioactives with enhanced antioxidant activity and bioavailability.

Production of highly concentrated oil-in-water emulsions using dual-channel microfluidization: Use of individual and mixed natural emulsifiers (saponin and lecithin).

The fabrication of concentrated oil-in-water emulsions is useful for reducing storage and transportation costs, as well as for providing desirable textural, optical, stability, and release characteristics in commercial products. In this study, 50wt% oil-in-water emulsions were produced from natural emulsifiers using high-pressure dual-channel microfluidization (89.6MPa, 1 pass). The particle size and charge characteristics of emulsions stabilized using a hydrophilic biosurfactant (quillaja saponin) or mixtures of hydrophilic and hydrophobic biosurfactants (quillaja saponin+soy lecithin) were measured. The physical stability of the emulsions was determined during storage under quiescent conditions (pH7, 25°C). The mean droplet diameter and polydispersity decreased with increasing hydrophilic and hydrophobic biosurfactant concentration. Surface potential measurements indicated that interfacial composition depended on the amount of hydrophilic and hydrophobic biosurfactant present. The inclusion of hydrophobic emulsifier in the oil phase and hydrophilic emulsifier in the aqueous phase prior to homogenization, led to the formation of smaller oil droplets than using the hydrophilic emulsifier alone. The relatively small size and polydispersity of the droplets in the mixed-emulsifier systems led to a higher emulsion viscosity and a better aggregation stability, i.e., there was a smaller change in particle size during storage. However, some creaming was still observed in the emulsions due to the presence of a fraction of relatively large droplets. In summary, concentrated emulsions stabilized by mixed biosurfactants may be advantageous for commercial application in certain food, beverage, and pharmaceutical products.

Controlling the potential gastrointestinal fate of ß-carotene emulsions using interfacial engineering: Impact of coating lipid droplets with polyphenol-protein-carbohydrate conjugate.

The impact of interfacial coatings comprised of polyphenol-protein-carbohydrate conjugates on the properties of nutraceutical-fortified lipid droplets during digestion was investigated. Surface-active chlorogenic acid-lactoferrin-polydextrose (CA-LF-PD) conjugate was synthesized as emulsifier to stabilize lipid droplets in ß-carotene-enriched oil-in-water emulsions. Changes in droplet size, charge, and microstructure were monitored as ß-carotene emulsions were passed through a simulated gastrointestinal tract model (mouth, stomach, small intestine). LF-coated droplets were unstable to flocculation at pH 8.0-9.0, due to the reduction in electrostatic repulsion, but CA-LF-PD conjugate-coated droplets were stable. Emulsions stabilized by ternary conjugate had better stability to droplet aggregation under simulated GIT conditions than other systems, which increased ß-carotene bioaccessibility. The importance of including an oral phase in the simulated GIT model was also demonstrated. The ternary conjugate-stabilized emulsions developed in this study have potential applications as protectors and carriers of hydrophobic drugs, supplements and nutraceuticals.

Potential physicochemical basis of Mediterranean diet effect: Ability of emulsified olive oil to increase carotenoid bioaccessibility in raw and cooked tomatoes.

Excipient emulsions have compositions and structures specifically designed to increase the bioavailability of nutraceuticals in foods that they are co-ingested with. In this study, olive oil excipient emulsions were shown to significantly increase the bioaccessibility of carotenoids from tomatoes using a simulated gastrointestinal tract (GIT) model (p<0.05): being 8.18±0.93%, 11.85±1.76% for raw tomato-buffer mixture, and cooked tomato-buffer mixture; While being 32.3±2.60%, 55.7±3.28% and 42.6±3.75% for raw tomato-emulsion mixture, cooked tomato-emulsion mixture (boiled together) and cooked tomato- emulsion mixture (tomato boiled alone). These effects were attributed to: (i) the ability of digested olive oil droplets to form mixed micelles in the small intestine that solubilized the carotenoids; and, (ii) the ability of natural antioxidants (phenolics) in the olive oil to protect the carotenoids from oxidation. Thermal treatment (boiling) significantly increased carotenoid bioaccessibility from the tomatoes digested with emulsion, which was attributed to plant tissue disruption at elevated temperatures facilitating carotenoid release (p<0.05). Carotenoid bioaccessibility was higher when the tomatoes were boiled with emulsions (55.7±3.28%) than when they were boiled alone and then added to emulsions (42.6±3.75%). In conclusion, this study indicates that olive oil emulsions boost the bioaccessibility and chemical stability of lipophilic nutraceuticals in tomatoes, which may make an important contribution to the potential health benefits of the Mediterranean diet.

Influence of lipid type on gastrointestinal fate of oil-in-water emulsions: In vitro digestion study.

The potential gastrointestinal fate of oil-in-water emulsions containing lipid phases from different sources was examined: vegetable oils (corn, olive, sunflower, and canola oil); marine oils (fish and krill oil); flavor oils (orange and lemon oil); and, medium chain triglycerides (MCT). The lowest rates and extents of lipid digestion were observed for emulsified flavor oil, followed by emulsified krill oil. There was no appreciable difference between the final amounts of free fatty acids released for emulsified digestible oils. Differences in the digestibility of emulsions prepared using different oils were attributed to differences in their compositions, e.g., fatty acid chain length and unsaturation. The particle size distribution, particle charge, microstructure, and macroscopic appearance of the emulsions during passage through the simulated GIT depended on oil type. The results of this study may facilitate the design of functional foods that control the digestion and absorption of triglycerides, as well as the bioaccessibility of hydrophobic bioactives.