Genesys 10 uv

Patties used for testing for lipid oxidation were removed from the display case on days 0, 3, and 7, vacuum packaged and frozen until further analysis. A modified version of lipid oxidation thiobarbituric acid reactive substances (TBARS) was conducted [19 (link),20 (link)]. Prior to completing TBARS analysis, patties were thawed at 4 °C for 12 h. From each patty, 2 g of meat was homogenized (AHS 250, VMR Power Max, Radnor, PA, USA) for 60 s with 8 mL of a cold (1 °C) 50 mM phosphate buffer mix standardized to a pH of 7, containing 0.1% ethylenediaminetetra acetic acid (EDTA), 0.1% n-propyl gallate, and 2 mL of trichloroacetic acid (Sigma, St Louis, MO, USA). Samples were then filtered through filter paper (Whatman No. 4), and duplicate 2-mL aliquots of clear supernatant were then transferred into 10 mL borosilicate tubes, mixed with 2 mL of 0.02 M 2-thiobarbituric acid reagent (Sigma, St Louis, MO, USA), and boiled at 100 °C for 15 min. Immediately after boiling, tubes were placed into an ice bath for 15 min. Absorbance was measured at 533 nm with a spectrophotometer (Thermo Fisher Scientific., model Genesys 10 UV, Waltham, MA, USA) and TBARS were calculated as mg of maldonaldehyde per kg of sample [21 (link)].

The content of Chl a and b and carotenoids was determined in 96% ethanol extracts [39 (link)] by analyzing the absorption spectra of the samples on a Genesys 10 UV spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA) at λ_max of 470, 649, and 665 nm. The content of UVAPs was determined using fully developed, healthy-looking upper leaves (8–12), which were kept for 24 h in acid methanol (methanol/water/HCl, 78:20:2) at +4 °C [40 (link)]. The optical density of the samples was determined in the UV range (maximum at 327 nm) using a spectrophotometer (Genesys 10 UV, Thermo Fisher Scientific, Waltham, MA, USA). The content of UVAPs was expressed in relative units per 100 mg of dry matter.

The dosage of phenolic compounds was carried out using the Folin–Ciocalteu colorimetric method [87 (link)] with adaptations. Gallic acid 0.2 mg/mL (Sigma Aldrich; Duque de Caxias, Brazil) was used as a standard in the construction of the analytical curve (5, 10, 20, 30, and 40 µg/mL). The samples, in triplicate, were added to water to complete the volume of 250 μL; then, 2250 μL of the reactive mixture (Folin–Ciocalteu) was added. After 30 min, the absorbance was determined at 750 nm in a spectrophotometer Genesys 10uv (Thermo Fischer; São Paulo, Brazil). The values were converted to indicate mg of phenolics/g of plant material.

The total phenolic contents of the extracts of Pitavia punctata were determined using the method described previously [16 (link)]. Briefly, a sample (160 μL) of the different extracts was mixed with 100 μL of Folin-Ciocalteu reagent and incubated 5 min before the addition of 300 μL of 20% sodium carbonate (Na₂CO₃); the reaction tubes were diluted to 1.2 mL with distiller water and then incubated for 1 h. The absorbance of the mixture was read at 765 nm using a spectrophotometer (Thermo Spectronic GENESYS 10 UV) and the quantification was made on the basis of a standard curve of Gallic acid. The results were expressed as mg of Gallic acid equivalents (GAE) per gram of extract.
The total flavonoids contents of the extracts were determined by the methodology described previously [17 ]. Briefly, a sample (200 μL) of the different extracts was mixed with 60 μL of 5% sodium nitrite (NaNO₂); after 6 min of incubation, 60 μL of 10% aluminium chloride (AlCl₃) was added and incubated for 6 min before the addition of 400 μL of 4% sodium hydroxide (NaOH). As reference, a calibration curve was made using Quercetin as a standard; the absorbance of the reaction mixture was measured at 415 nm and the results were expressed as mg of Quercetin equivalents (QE) per gram of extract.

An overnight culture of A. baumannii A118 was prepared by inoculation of a single colony into 5 mL of LB broth, followed by incubation at 37 °C with good aeration (120 rpm). A 1:100 dilution into 50 mL of fresh LB broth containing tryptone (10 g/L), yeast extract (5 g/L) (Difco) and sodium chloride (0.5, 2.5, 5, 7.5 or 10 g/L) was done, followed by incubation at 37 °C and agitation at 120 rpm for 320 min. Samples were collected at 30 and 60 min and then each 20 min, and the optical density at 600 nm (OD_600nm) was measured in a spectrophotometer (Genesys 10UV, Thermo Scientific, Madison, WI, USA). The growth curves were constructed plotting the OD_600nm values versus the incubation time.

Measurement of OD₆₂₅ was performed with the photometer Genesys 10 UV (Thermo Fisher Scientific, USA). pH was measured applying pH indicator strips pH 0–10 (Merck, Germany). Glucose concentration was determined using Diabur Test 5000 (Roche Diagnostics, Switzerland) or HPLC. HPLC analysis of xylose, acetate, ethanol, lactate, HMF, furfural, levulinic acid and formate was performed with the column Aminex HPX-87 H (Bio-Rad, USA) and quantified using a refractive index detector 8120 (Bischoff, Germany). The volumetric flow rate of the mobile phase (5 mmol/L sulfuric acid) was 0.4 or 0.6 mL/min at 65 °C for different detection times up to 45 min depending on the product to be determined.