Samples kept at 30 °C were only used to evaluate oxidative stability. Samples were taken every month and analyzed for all parameters. Chemical composition of all six chocolate samples Selleck Doxorubicin was determined according to the AOAC methods (AOAC, 2005). Carbohydrates were obtained by difference. Mechanical properties of chocolates (hardness) were measured according to the method proposed by Afoakwa, Paterson,
Fowler, and Vieira (2008) using TA-XT2 Texture Analyzer (Stable Micro Systems, Surrey, UK). Maximum penetration and withdrawal forces through a sample were determined (1.0 mm/s, 5 mm of penetration at 20 °C). The color of dark chocolate was measured using a ColourQuest-XE colorimeter (Hunter Assoc. Laboratory, Reston, USA), using the CIE standard illuminant D65 as reference. Ten grams per sample were compressed into an optical cell (vision area 0.37 pol.). Color was expressed as lightness (L*), redness (a*) and yellowness (b*), using CIELab
parameters. A hedonic sensory evaluation was carried out by an untrained panel consisting of thirty individuals composed by the students and employees from the Faculty staff, who liked of bitter chocolate. Approximately 10 g of dark chocolate was placed in a small plate coded with 3-digit random numbers. Each panelist received a set of 3 samples (CONT, PHYT and PHAN) in a different order (3!), and they were instructed to rinse their mouth with water between samples evaluation. Acceptability analysis was performed using a 9 point hedonic scale, considering 9 as “extremely like” and 1 as
“extremely dislike”. The Navitoclax cost http://www.selleck.co.jp/products/Abiraterone.html extraction of chocolate lipids was performed according to AOAC official method 920.75 (AOAC, 2002). About 5 g of the chocolate bars was mixed with 10 mL diethyl ether for 1 min. The tubes were centrifuged and the upper phase separated. The extraction was repeated twice and the combined extract was filtered using sodium sulfate. Ether extracts were evaporated and resuspended with 1 mL of hexane. Hydroperoxide content of the extracted fat was determined according to Shantha and Decker (1994). PV was determined in 50 μL of lipid extract at 510 nm, by using a UV–VIS mini 1240 spectrophotometer (Shimadzu, Kyoto, Japan), and it was calculated from the absorbance. The hydroperoxide content was determined using a standard curve prepared with known concentrations of cumene hydroperoxide. Concentrations were expressed as mmol/kg of fat. The chocolates fatty acid profile was determined according to AOCS Ce 1b-89 (AOCS, 2001). The chromatographic analysis was carried out using a gas chromatograph GC (Agilent 7890 A GC System, Agilent Technologies Inc., Santa Clara,USA). A fused silica capillary column (J&W DB-23 Agilent 122-236; 60m × 0.25 mm i.d., 0.15 μm film thickness) was used for injection.