Uv vis 1240

The total polyphenol content (TPC) in beetroot was determined photometrically (spectrophotometer Shimadzu UV/VIS-1240) in a lyophilised sample by the method of Lachman et al. (2005) and expressed as milligram of gallic acid equivalent (GAE) per kilogram of dry weight (d.w.). The GA is usually used as a standard unit for phenolic content analysis because of the wide spectrum of phenolic compounds. The TPC was determined by using Folin-Ciocalteau phenol reagent, which was added to a volumetric flask containing 100 ml of extract. The prepared mixture was mixed. After 3 min, 5 ml of sodium carbonate solution (20%) was sequentially added to the mixture. The mixture was adjusted to 50 ml by adding distilled water. After 2 h, samples were centrifuged for 10 min, and sample absorbance was measured at a wavelength of 765 nm against blank. The polyphenol content was sequentially calculated from a standard curve plotted with a known concentration of GA.

The PB was grown (25°C) in a Pikovskaya medium and treated with Ca 3 (PO 4 ) 2 and AlPO 4 (Sigma, USA), FePO 4 (Aldrich, USA), pNPP or Na-phytate as sources of P. The amount of dissolved P was determined calorimetrically by staining the samples with ammonium vanadomolybdate and read at a wavelength of 413 nm using a UV-VIS-1240 Shimadzu spectrophotometer.

The biosorption studies were carried out in batch mode. A known amount of biosorbent was introduced in flasks containing certain concentration of MB. The mixture was stirred during a determined time. While equilibrium was reached, the absorbance of supernatants was determined by spectrophotometer (Shimadzu UV-vis 1240) at the maximum absorbency visible wavelength (λmax= 664 nm).
The uptake of biosorbed dye per unit mass of biosorbent at equilibrium, qe (mg g -1 ), and the biosorption percentage, (% removal), were calculated using the following relationships:
).
(1)
Where V is the volume of the solution (L), m is the mass of biosorbent (g), C0 is the initial MB concentration (mg L -1 ), Ce is the MB equilibrium concentration (mg L -1 ) in liquid phase and qe is the dye quantity biosorbed at equilibrium (mg g - 1 ).

The chemicals used for analysis were: Folin-Ciocalteau reagent, monohydrate of gallic acid p.a., anhydrous natrium carbonate p.a., aluminium chloride p.a., sodium nitrite p.a., sodium hydroxide p.a., 35%, catechin hydrate 98%, 2,2diphenyl-1-picrylhydrazyl (DPPH) radical p.a., methanol p.a. All analysed parameterstotal polyphenol content, total flavonoid content and antioxidant activity in wines were analysed using UV/VIS spectrophotometry (spectrophotometer Shimadzu UV/VIS-1240, Shimadzu, Japan).

The chemicals used for all analysis were: Folin-Ciocalteau reagent, monohydrate of gallic acid p. a., anhydrous sodium carbonate p. a., citric acid p. a., disodium hydrogenphosphate dodecahydrate, 35 % hydrochloric acid p. a., ethanol p. a., methanol p. a., 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical p. a., Trolox (pure).
All analysed parameters -total polyphenol content, total anthocyanin content, antioxidant activity and wine colour density in wines were analysed by UV/ VIS spectrophotometry (spectrophotometer Shimadzu UV/VIS -1240, Shimadzu, Japan).