Fabrication and characterization of polydopamine-mediated zein-based nanoparticle for delivery of bioactive molecules.

In this study, a combination of whey protein (hydrophilic coating) and polydopamine (crosslinking agent) was used to improve the stability and functionality of quercetin-loaded zein nanoparticles. There are two key benefits of the core-shell nanoparticles formed. First, the ability of the polydopamine to bind to both zein and whey protein facilitates the formation of a stable core-shell structure, thereby protecting quercetin from any pro-oxidants in the aqueous surroundings. Second, neutral and hydrophilic whey proteins were used for the surface coating of the nanoparticles to further enhance the sustained and slow release of quercetin, facilitating its sustained release into the body at a slow and steady rate. The results of this study will promote the innovative development of precise nutritional delivery systems for zein and provide a theoretical basis for the design and development of dietary supplements based on hydrophobic food nutrient molecules.

Recent advances in natural gums as additives to help the construction and application of edible biopolymer gels: the example of hydrogels and oleogels.

Novel, innovative approaches like edible gels (hydrogels and oleogels) are important food materials with great scientific interest due to their positive impacts on structural and functional foods and other unique properties. Biopolymers (protein, starch and other polysaccharides) can be excellent and cost-effective materials for the formed edible gels. Recently, natural gums, although also as biopolymers, are preferred as additives to further improve the textural and functional properties of edible gels, which have received extensive attention. However, these studies have not been outlined in previous reviews. In this review, we highlighted the advantages of gums as additives to construct edible gels. Moreover, the various roles (including electrostatic or covalent interactions) for natural gums in regulation of food gel properties (solvent-holding and rheological properties) are highlighted. Finally, the use of natural gums as additives to improve the stability and targeted delivery of phytochemicals in food gels and their application in food systems are summarized. The information covered in this article may be useful for the design of functional foods that can better meet personalized needs of people.

Interactions between plant-derived antioxidants and cyclodextrins and their application for improving separation, detection, and food quality issues.

Plant-derived antioxidants (PD-AOs) are important for food preservation, as well as for human health and nutrition. However, the poor chemical stability and water solubility of many PD-AOs currently limit their application as functional ingredients in foods and pharmaceuticals. Moreover, it is often difficult to isolate and detect specific antioxidants in multi-component systems, which again limits their potential in the food and medical industries. In this review, we highlight recent advances in the use of cyclodextrins (CDs) to overcome these limitations by forming simple, modified and competitive host-guest interactions with PD-AO. The host-guest properties of CDs can be used to enhance the separation efficiency of PD-AOs, as well as to improve their dispersion and stability in food systems. Moreover, the competitive complexation properties of CDs with target molecules can be used to selectively isolate PD-AOs from multi-component systems and develop detection technologies for PD-AOs. Overall, CD-antioxidant interactions have great potential for addressing isolation, detection, and food quality issues.

Optimization and Kinetics Modeling of Microwave-Assisted Subcritical n-Butane Extraction of Tigernut Oil.

In this study, tigernut oil was extracted from tigernut meal by subcritical n-butane extraction with the assistance of microwave pretreatment. Effects of microwave pulse duration, particle size of tigernut meal, and subcritical extraction variables (temperature, time, solid-liquid ratio, number of extraction cycles) on extraction efficiency were examined by single-factor experiments and Response Surface Methodology (RSM) modeling. The results indicate that microwaving (560 W, 6 min) significantly increased the subcritical extraction efficiency. The variation of extraction yield could be interpreted as a nonlinear function of extraction time, temperature and liquid-solid ratio. Changing the independent variables could affect the oil extraction efficiency. The subcritical extraction of tigernut oil with a liquid-solid ratio of 3.62 kg/(kg of tigernut meal) at a temperature of 52°C for 32 min after three extraction cycles produced the most oil, and a maximum yield (24.736%) of tigernut oil was achieved. The ratio of unsaturated to saturated fatty acids (4.68 UFA/SFA), low acid value (3.30 mg KOH/g oil), low peroxide value (0.28 meq.kg-1), and preponderance of oleic acid indicate a high-quality oil. To describe the extraction kinetics, a modified Brunner's mathematical model was used. The model fit the experimental data well over the entire operating range, and the explanation coefficient exceeds 96%. Our results can be used to develop an optimized method for subcritical fluid extraction of tigernut oil and can move industry further toward implementing microwave-assisted subcritical extraction in oil processing.

The physicochemical properties of starches isolated from defatted tigernut meals: Effect of extrusion pretreatment.

If the tigernut meal left after oil extraction is used as a material for starch resources instead of being wasted, the industrial value of tigernut would be improved. Thus, we investigated the effect of extrusion before oil extraction on the yield, structure and function of starches within tigernut meals (TMS). Compared with the yield of native starch, the yield of TMS-130-11 (barrel temperature: 130 °C; feed moisture: 11 %) was increased by 1.97 %, and that of TMS-140-11 (barrel temperature: 140 °C; feed moisture: 11 %) was decreased by 7.82 %. The starches cannot be obtained when the barrel temperature is above 140 °C with 11 % feed moisture. Extrusion slightly decreased the relative crystallinity and increased the ratio of B2-chains in amylopectin. These changes resulted in reductions in peak viscosity while improving the elastic properties of the starch gel. These results will provide useful information regarding the use of starch isolated from tigernut meal.

Effects of isolation conditions on structural and functional properties of the seed gum from Chinese quince (Chaenomeles sinensis).

Chinese quince seed gum (CQSG) extracted under water-, alkali- and acid- conditions at 25, 50, and 80 °C, were evaluated in terms of yield, monosaccharide composition, molecular distribution, thermal gravimetry, emulsifying stability, rheological properties, and free radical scavenging ability. The results showed that the yield of CQSG increased to 3.9% after water extraction at 80 °C. Alkali and acid treatments promoted the conversion of neutral sugars to the uronic acid branch. Regardless of the extraction temperature, the xylose chain was the main component (35%-40%); however, a reduction was observed as the extraction temperature increased to 80 °C. All CQSG solutions extracted under these isolation conditions exhibited non-Newtonian rheological behavior. Compared to water-extracted samples, the alkali-extracted samples showed the worst thermal stability, while the acid-treated samples showed the worst emulsifying stability. This study provides theoretical support for the potential application of CQSG polysaccharides in the food and pharmaceutical industries.