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.

Novel carbohydrate-triazole derivatives as potential α-glucosidase inhibitors.

A series of novel pyrano[2, 3-d]trizaole compounds were synthesized and their α-glucosidase inhibitory activities were evaluated by in vitro enzyme assay. The experimental data demonstrated that compound 10f showed up to 10-fold higher inhibition (IC5074.0 ± 1.3 µmol·L-1) than acarbose. The molecular docking revealed that compound 10f could bind to α-glucosidase via the hydrophobic, π-π stacking, and hydrogen bonding interactions. The results may benefit further structural modifications to find new and potent α-glucosidase inhibitors.

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.

Nanoemulsions: An emerging platform for increasing the efficacy of nutraceuticals in foods.

Both whole and processed foods contain numerous bioactive substances that improve human health and performance, including macronutrients, micronutrients, and nutraceuticals. Many of these substances are strongly hydrophobic and chemically labile, which can diminish their beneficial health effects, since only a small fraction of the ingested amount is actually absorbed and utilized by the body. In the gastrointestinal tract, the overall bioavailability of a hydrophobic substance is determined by its bioaccessibility, transformation, and absorption. The design of functional foods with enhanced biological activity depends on identifying the relative importance of these three different processes for specific bioactive substances, and then using this knowledge to optimize the nature of food matrices to boost bioavailability. In this review, we focus on the utilization of oil-in-water nanoemulsions for this purpose because their compositions, structures, and properties can be easily manipulated. Nanoemulsions can be used as delivery systems where the hydrophobic bioactive substances are loaded into the oil phase either before or after homogenization. Alternatively, they can be utilized as excipient systems. In this case, the bioactive substances are located within an existing food product (such as a fruit or vegetable), which is then consumed with a specially-designed excipient nanoemulsion (such as a sauce, dressing, or cream). Research has shown that for both delivery and excipient systems, the oral bioavailability of hydrophobic bioactives can be enhanced considerably in the presence of a nanoemulsion, provided its properties have been carefully designed. This review article outlines the principles of the design of nanoemulsion-based delivery and excipient systems for boosting the bioavailability of hydrophobic bioactive substances.

Impact of Food Emulsions on the Bioaccessibility of Hydrophobic Pesticide Residues in Co-Ingested Natural Products: Influence of Emulsifier and Dietary Fiber Type.

In the typical Western diet, fruits and vegetables are often consumed with food products that exist as oil-in-water emulsions, such as creams, dressings, and sauces. Studies have shown that coingestion of fruits and vegetables with emulsions can increase the bioavailability of beneficial lipophilic bioactive agents, such as nutraceuticals or vitamins. Agricultural produce, however, may also be contaminated with low levels of detrimental lipophilic agents, such as hydrophobic pesticides. We therefore examined the impact of coingesting a common agricultural product (tomatoes) with model food emulsions on the bioaccessibility of a hydrophobic pesticide (chlorpyrifos). The impact of emulsifier types (phospholipids, whey protein, Tween 80) and dietary fiber types (xanthan, chitosan, ß-glucan) on the bioaccessibility of the pesticide was measured using a simulated gastrointestinal model. Chlorpyrifos bioaccessibility depended on the type of emulsifier used to formulate the emulsions: phospholipids > Tween 80 > whey protein. Dietary fiber type also influenced pesticide bioaccessibility by an amount that depended on the nature of the emulsifier used. Overall, our results suggest that the bioaccessibility of undesirable pesticides on fruits and vegetables will depend on the nature of the emulsions they are consumed with.

Effect of dietary fibers on the structure and digestibility of fried potato starch: A comparison of pullulan and pectin.

The granular morphology, long-range and short-range ordered structures of fried potato starch were measured in the absence and presence of the dietary fibers. The in vitro digestibility of the fried starchy samples was also quantified using the Englyst method with logarithm-of-slope (LOS) analysis. After frying, the starch granules disintegrated, their internal crystalline structure disappeared, and the quantity of double helices present decreased. As a result of these changes, the fried starch was digested rapidly. Addition of pullulan or pectin to the samples prior to frying, reduced the structural changes observed in the starch granules during frying. Consequently, the fractions of slowly digestible and resistant starch (SDS and RS) increased significantly in the presence of the dietary fibers. These effects were attributed to the ability of the dietary fibers to sequester some of the water, thereby reducing starch granule structural changes, as well as due to their ability to coat the starch granules and interfere with the starch digestion process.

Impact of amylose content on structural changes and oil absorption of fried maize starches.

The absorption of oil during frying has important implications for food quality, cost, and nutrition. Maize starches with low (WMS), intermediate (NMS), and high amylose (HAMS) contents were therefore heated in oil to mimic the frying process, and the impact of amylose content on the hierarchical structures and oil absorption of the fried starches was evaluated. Amylose affected the oil absorption by interfering with the structural evolution of the starch or by directly interacting with the lipids during frying. At low moisture level (20%), the granular state was preserved after frying and so the size and porosity of the granules played a dominant role in the oil absorption process, explaining why the highest oil absorption occurred in WMS. At 40% moisture content, NMS absorbed the most oil because of its granular morphology and lower crystallinity. At 60% moisture content, HAMS absorbed more oil than NMS, because more amylose molecules in HAMS provided more hydrophobic helical cavities available for lipids.

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.

Controlled-release of antacids from biopolymer microgels under simulated gastric conditions: Impact of bead dimensions, pore size, and alginate/pectin ratio.

The highly acidic nature of the gastric fluids inside the human stomach can cause have health problems in certain individuals e.g., acid reflux and ulcers. Antacid-loaded biopolymer microgels can be used to control the acidity of the gastric fluids, which may be useful for developing functional foods to treat these problems. In this study, the impact of biopolymer microgel dimensions and composition on the dissolution rate of encapsulated antacid was determined under simulated gastric conditions. The microgels were formed by injecting antacid (magnesium hydroxide) and biopolymers (alginate or alginate/pectin) into a calcium chloride solution to promote cross-linking. Microgels of varying dimensions were formed using either a hand-held syringe or a vibrating nozzle encapsulation device with different nozzle sizes. The rate of antacid dissolution was measured using an automatic titration device (pH stat) that added HCl solution into the simulated gastric fluids to maintain a constant pH of 2.5. The antacid dissolution rate decreased with increasing microgel diameter (300 to 1660 µm) and decreasing pore size (0.8 to 2.0% alginate). The slowest dissolution rate was observed in microgels containing 80% alginate and 20% pectin, which may have been due to the impact of biopolymer composition on bead dimensions and pore size. The results of this study may be useful for the design of biopolymer microgels that can control the release of antacids in the stomach, thereby leading to better control over the pH of the gastric fluids.

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.

Enhancement of carotenoid bioaccessibility from carrots using excipient emulsions: influence of particle size of digestible lipid droplets.

The influence of initial lipid droplet size on the ability of excipient emulsions to increase carotenoid bioaccessibility from carrots was investigated using a simulated gastrointestinal tract (GIT). Corn oil-in-water excipient emulsions were fabricated with different surface-weighted mean droplet diameters: d32 = 0.17 µm (fine), 0.46 µm (medium), and, 10 µm (large). Bulk oil containing a similar quantity of lipids as the emulsions was used as a control. The excipient emulsions and control were mixed with pureed carrots, and then passed through a simulated GIT (mouth, stomach, and small intestine), and changes in particle size, charge, microstructure, lipid digestion, and carotenoid bioaccessibility were measured. Carotenoid bioaccessibility significantly increased with decreasing lipid droplet size in the excipient emulsions, which was attributed to the rapid formation of mixed micelles that could solubilize the carotenoids in the intestinal fluids. These results have important implications for designing excipient foods, such as dressings, dips, creams, and sauces, to increase the bioavailability of health-promoting nutraceuticals in foods.

Enhancing Nutraceutical Bioavailability from Raw and Cooked Vegetables Using Excipient Emulsions: Influence of Lipid Type on Carotenoid Bioaccessibility from Carrots.

The influence of the nature of the lipid phase in excipient emulsions on the bioaccessibility and transformation of carotenoid from carrots was investigated using a gastrointestinal tract (GIT) model. Excipient emulsions were fabricated using whey protein as an emulsifier and medium-chain triglycerides (MCT), fish oil, or corn oil as the oil phase. Changes in particle size, charge, and microstructure were measured as the carrot-emulsion mixtures were passed through simulated mouth, stomach, and small intestine regions. Carotenoid bioaccessibility depended on the type of lipids used to form the excipient emulsions (corn oil > fish oil ≫ MCT), which was attributed to differences in the solubilization capacity of mixed micelles formed from different lipid digestion products. The transformation of carotenoids was greater for fish oil and corn oil than for MCT, which may have been due to greater oxidation or isomerization. The bioaccessibility of the carotenoids was higher from boiled than raw carrots, which was attributed to greater disruption of the plant tissue facilitating carotenoid release. In conclusion, excipient emulsions are highly effective at increasing carotenoid bioaccessibility from carrots, but lipid type must be optimized to ensure high efficacy.