Extraction of bio-hydroxyapatite from devilfish (Loricariidae) for the fluoride and cadmium adsorption from water and its feasible photocatalytic properties.

In this study, the adsorption capacity of bio-hydroxyapatite (Bio-HAp) from devilfish for the removal of F- and Cd(II) from aqueous solutions was investigated. This material was synthesized according to a 2FI factorial experimental design by varying the extraction conditions for Bio-HAp, including the type of pretreatment (alkaline and peroxide), the calcination temperature from 550 to 850 °C, and the sonication process. The maximum adsorption capacities were 8.48 and 83.56 mg g-1 for F- and Cd(II), respectively. Statistical analysis showed the importance of the type of pretreatment, temperature, and sonication for adsorption. The predicted optimal conditions were Bio-HAp extracted from bone with peroxide pretreatment, calcination at 550 °C and sonication. The surface of the Bio-HAp was found to be mesoporous and basic in character. TGA, FT-IR and SEM-EDS characterizations confirmed the presence of F- and Cd(II) on the Bio-HAp surface and confirmed the adsorption mechanisms by electrostatic forces, ion exchange, and chemisorption. The Praunitz-Rake model of adsorption isotherm showed better agreement with the equilibrium adsorption data of F- and Cd(II) at pH 7. Furthermore, photodegradation experiments showed 100% degradation methylene blue (MB) under natural sunlight. This study indicates an effective photodegradation process, suggesting high adsorption capacity of the samples. The use of devilfish as an adsorbent promises to be a viable and sustainable option for the removal of fluoride and cadmium from water, and for use in photodegradation experiments.

Modification on the polyphenols and dietary fiber content of grape pomace by instant controlled pressure drop.

Instant controlled pressure drop (DIC) has been used as a pre-treatment to increase extractable polyphenols (EPP), mainly attributed to matrix structure expansion. This work aimed to evaluate the effect of DIC on non-extractable polyphenols (NEPP), EPP, and dietary fiber on grape pomace. At 0.2 MPa-60 s was observe an increase of total EPP and total anthocyanins. Despite the increment of EPP, was observe the lowest anthocyanins and non-extractable proanthocyanidins content at 0.4 MPa-120 s. This increase was due to a partial transformation of anthocyanins into phenolic acids and the depolymerization of proanthocyanidins. Also was observe partial solubilization of insoluble dietary fiber. Morphologically, the size of the pores generated by DIC was more significant at higher pressures. Thus, DIC modified the morphology and profile of the polyphenols of grape pomace, producing phenolic compounds of simpler structure and improving their antioxidant capacities.

Improvement of physico-chemical properties and phenolic compounds bioavailability by concentrating dietary fiber of peach (Prunus persica) juice by-product.

BACKGROUND: This study aimed to concentrate dietary fiber (DF) from peach (Prunus persica) juice by-product (PJBP), to improve its functional properties, and its polyphenols bioavailability. The dietary fiber concentrates (DFCs) were obtained from PJBP using water/ethanol treatments (100:0, 20:80, 50:50, 80:20, and 0:100, v/v) at 1:5 ratio (wet weight/solvent, w/v) for 5 and 20 min at 21 °C. RESULTS: All treatments concentrated condensed tannins, total and insoluble DF, with the highest content found with 100% H2 O treatment. The major polyphenols of DFC were 4-O-caffeoylquinic, chlorogenic, and 1,5-di-O-caffeoylquinic acids. Water and oil retention capacity and maximum glucose diffusion rate were improved mainly with 100% H2 O treatment. Healthy rats were fed with a standard diet supplemented with 8% of PJBP, DFC obtained with 100% H2 O for 5 min, or DFC obtained with 20% EtOH for 5 min. Gastrointestinal digesta weight and viscosity were increased in animals supplemented with 100% H2 O DFC. Moreover, the urinary excretion of polyphenol metabolites, mainly glucuronide and sulfate conjugates, was increased with this treatment, indicating a greater bioavailability of PJBP polyphenols, which was associated with an increased dietary fiber porosity. CONCLUSION: Water treatment could be used to potentiate PJBP functional properties and polyphenols bioavailability. © 2017 Society of Chemical Industry.