RESUMO
Kombucha beverage produced through fermentation of sugared tea using bacteria and yeast has gained attention for its beneficial health benefits. However, the cost linked to the raw materials often increases the upstream process expenses, thereby the overall operating expenditures. Thus, there is a need to explore alternative waste and cost-effective raw materials for Kombucha fermentation. The present study, compared the physico-chemical and microbial growth pattern of Kombucha beverage production using tea waste from the tea processing industries with that of the green/black tea, reporting similar trends irrespective of its type. Further, the amplicon sequencing of 16S rRNA showed dominant presence of Komagataeibacter rhaeticus and high throughput sequencing of ITS1 confirmed the presence of yeast species similar to Brettanomyces bruxellensis in the tea waste based Kombucha beverage. Appreciable amount of carbohydrates (8.5/100 g) and energy (34 kcal/100 g) with appropriate organoleptic properties favourable for human consumption were also observed during the nutritional content and qualitative property assessment. The overall study showed a broad taxonomic and functional diversity existing during Kombucha fermentation process with tea waste to maintain a sustained eco-system to facilitate cost-effective beverage production with desired properties for safe consumption. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05476-3.
RESUMO
The aim of the present paper is to develop a novel method for fluorimetric determination of uranium in rock/mineral solutions containing hydrolysable elements such as Nb, Ta, Zr and Ti sequestered by bi-fluoride. These rocks/minerals are decomposed with ammonium bi-fluoride (NH4HF2) and sulfuric acid (H2SO4) mixture. Uranium in such mineral solutions is selectively extracted into ethyl acetate with 2,3-dihydroxynaphthalene at pH 10-12 in the presence of cetyltrimethylammonium bromide, prior to its pellet fluorimetric determination. Optimizations of certain parameters such as the effects of fluoride fluxes, mineral acids, masking agents and diverse ions are discussed in detail. This method is applied for the determination of uranium in synthetic mixtures and a set of in-house reference refractory minerals including certified reference material X1807 with a high degree of accuracy and precision. The results for the refractory minerals using the proposed method are in excellent agreement with results obtained by other standard methods. The novelty of the proposed method is that the decomposition mixture (NH4HF2/H2SO4) inhibits the hydrolysis of hydrolysable elements by formation of their soluble fluoro complexes, and the separation of uranium using the complexing agent 2,3-dihydroxynaphthalene is more eco-friendly compared to existing the conventional solvent extraction system using aluminum nitrate as the salting out agent.
RESUMO
A simple and rapid solid phase extraction (SPE) procedure has been developed for the extraction and determination of uranium in water samples. The method is based upon the adsorption of uranium(VI)-2,3-dihydroxynaphthalene complex on microcrystalline naphthalene at the pH range 10 - 12 in the presence of a counter cation cetyltrimethylammonium ion. The solid mass consisting of uranium-2,3-dihydroxynaphthalene-CTA complex and naphthalene is ignited in the furnace at a temperature of 700°C for 1 h and then digested in dil. HNO3 solution. Uranium is then determined by LED fluorimetry using fluorescence enhancing pyrophosphate buffer. The effects of different variables like pH of the solution, reagent concentrations, counter cations, stirring time, interfering ions etc. have been investigated thoroughly for the quantitative recovery of uranium. The accuracy of the developed method has been ascertained by standard addition method as well as conventional pellet fluorimetry method involving co-precipitation of uranium using aluminum phosphate as a carrier.
RESUMO
There is a dearth of biologically active matrices for the encapsulation of bone cells. Here, we hypothesize that the use of gum tragacanth (GT) with alginate might improve the biological properties of calcium alginate (CA) beads, a common cell encapsulation system. We show that the incorporation of GT in the bead-composition significantly improves the molecular transport, swelling and degradation properties of the CA bead. Although no significant molecular interaction between GT and CA was found, a decrease in the concentration of calcium with an increase in GT concentration was noticed. We show that the presence of GT in the bead-composition resulted in improved viability, proliferation, and differentiation of encapsulated bone cells. We further demonstrate that bone cell loaded CA-GT beads are capable of inducing angiogenesis. In conclusion, we prove that CA-GT beads are more osteo-conductive and proangiogenic in comparison to pure CA beads.
