Unlocking the potential of rice bran oil body as fat replacement in cookies: single and double crosslinked binary emulsion-filled gels based on lutein-loaded rice bran oil body emulsion.

BACKGROUND: Rice bran oil body is rich in nutritional value, which is a byproduct of rice processing. The aim of this study is to develop a novel emulsion-filled gel with lutein-loaded rice bran oil body and investigate its functionality as a fat replacer in cookies. The effects of incorporating structured oil body in the form of emulsion-filled gel instead of butter in cookies with a ratio of 0, 10, 20 and 50 wt% formulation were determined by measuring appearance, texture, thermodynamic properties, moisture distribution and microstructure. RESULTS: The results demonstrated the relationship between geometry, moisture and structure. The 20 wt% emulsion-filled gel substitution ratio yielded mobility and distribution abilities of melted fat and sugar in the cookies that were closest to those of butter. The addition of emulsion-filled gel increased the L* value and decreased the a* value, while the b* value of the cookie increased due to the advanced delivery of lutein by oil body. By controlling the addition ratio, the texture of the cookies can be adjusted. Starch granules were separated due to colloidal particles, reducing saturated fat content and decreasing cookie gelatinization enthalpy. The fat coating on starch particles enhanced the binding capacity of free water, improving air entrapment and forming a constrained gluten network structure. CONCLUSION: These findings provide a theoretical basis for rice bran oil body as a novel substitute for butter in the development of healthy, high-quality cookies. © 2024 Society of Chemical Industry.

[Study on the spectrophotometric determination of hydroxyl free radical from low power trench-type ultrasound].

Under the condition of different pH (7-11) and different ethanol volume fraction (45% to 85%), the ultraviolet-visible absorption spectra of malachite green were studied in neutral and alkaline ethanol solution, the maximum absorption wavelength at 620 nm was found, and the matching degree of standard curve was better established. In low power trench-type ultrasound apparatus, the absorption of the malachite green solution was measured under ultrasound and non-ultrasound, respectively. the difference values of the ultraviolet absorption of the malachite green solution under low power trench-type ultrasound were measured results of the hydroxyl free radical oxidation degrading malachite green, therefore hydroxyl free radical from low power trench-type ultrasound was determined indirectly. Then the contents of hydroxyl free radical in four conditions were measured. The detection limit of the method of 8.4 x 10(-6) mmol x L(-1) and the relative standard deviation of the method of 9.4 x 10(-5) - 3.7 x 10(-4) mmol x L(-1) were determined, a higher testing precision and good reproducibility were confirmed. It can be applied for fast detection of neutral and alkaline ethanol solution system in the case of very low concentration of hydroxyl free radicals. Since malachite green is heat sensitive, so compared to measuring temperature, the method possessed better functions for thermal effects of ultrasound.

Enhancing the physicochemical stability and digestibility of DHA emulsions by encapsulation of DHA droplets in caseinate/alginate honeycomb-shaped microparticles.

Docosahexaenoic acid (DHA) was encapsulated in caseinate/alginate microparticles by adjusting the pH based on the electrostatic complexation, in order to improve the physicochemical stability and digestibility of single caseinate-stabilized DHA emulsions. In this study, relatively stable honeycomb-shaped DHA microparticles were formed by electrostatic complexation between positively charged caseinate-coated DHA droplets, caseinate and negatively charged alginate at pH 4.5. The zeta-potential, particle size, size distribution, physical stability, microstructure, DHA oxidation and free fatty acids (FFA) release rate in a simulated gastrointestinal tract (GIT) model were determined. Dynamic light scattering (DLS) and confocal laser scanning microscopy (CLSM) measurements indicated that DHA microparticles had a particle size (1521.00 ± 39.15 nm) significantly larger than that of caseinate-stabilized DHA emulsions (243.23 ± 4.51 nm). The microparticles were much more stable near the isoelectric point (pI) of the adsorbed proteins compared with the single emulsions according to the original transmissions of LUMiSizer. The cryo-scanning electron microscopy (Cryo-SEM) images also showed that the microparticles formed a specific honeycomb-shaped network structure with more uniform distribution and without aggregation. The incorporation of DHA droplets into caseinate/alginate microparticles significantly ameliorated their chemical stability. GIT studies showed that the digestion of DHA microparticles was enhanced which was due to more open loose structures compared with the large-scale close-knit aggregation of DHA emulsion droplets. This study may provide useful information for the stabilization of functional food components and rational design of nutraceutical delivery systems.

The Stability, Microstructure, and Microrheological Properties of Monascus Pigment Double Emulsions Stabilized by Polyglycerol Polyricinoleate and Soybean Protein Isolate.

Monascus pigment is a natural food pigment and is commonly used for coloring and as antiseptic of cured meat products, confectionery, cakes, and beverages. However, Monascus pigment is sensitive to environmental conditions. The main aim of this study was to investigate the effect of polyglycerol polyricinoleate (PGPR) and soy protein isolate (SPI) on the particle size, zeta potential, physical stability, microstructure, and microrheological properties of Monascus pigment double emulsions. The effects of ionic strength, heating, and freeze thawing treatment on the stabilities of Monascus pigment double emulsions were also characterized. It was found that the optimum PGPR and SPI concentrations for fabricating Monascus pigment double emulsion were 3.6 and 3.0 wt%, respectively. The fabricated Monascus pigment double emulsion was composed of fine particles with narrow and uniform size distributions. Microrheological property results suggested that the elastic characteristic of the Monascus pigment double emulsion was dominated with increasing PGPR and SPI contents. It was mainly due to the increased collision and interaction between the droplets during the movement resulting in force increasing. Monascus pigment double emulsions with <5 mM CaCl2 prevented calcium to destroy the physical stability of emulsions, while Monascus pigment double emulsions with more than 10 mM CaCl2 formed creaming. After freeze thawing treatment, creaming occurred in Monascus pigment double emulsion. However, it was stable against heating treatment due to heating leading to a dense network structure. It could be contributed to the practical applications of Monascus pigment double emulsions in food products.