Optimization of Matrix Solid-Phase Dispersion Method for Extraction of Aflatoxins from Cornmeal

An extraction method for simultaneous determination of aflatoxins (AFLAs) G2, G1, B2, and B1 in cornmeal, based on vortex-assisted matrix solid-phase dispersion (MSPD) and high-performance liquid chromatography (HPLC) with fluorescence detection was optimized by a central composite design, validated and applied. Multivariate analysis was performed to evaluate the effect of cornmeal composition on AFLA extraction. The amount and proportion of solid support (celite and C18) and volume of elution solvent (methanol and acetonitrile) were the variables tested. The mobile phase of methanol/acetonitrile/water (24:14:62, v/v/v) in isocratic elution mode provided satisfactory AFLA separation. The best recoveries (85.7 to 114.8%) were obtained when the sample preparation contained 25 mg C18 as solid support and 10 mL of elution solvent. The limits of detection ranged from 0.01 to 0.04 ng g^?1, and the limits of quantification varied from 0.02 to 0.1 ng g^?1. The optimized method was suitable for coarse and medium grind cornmeal. Multivariate correlation analysis showed that the main interferers for AFLA recovery were proteins and sugars.     

Winery grape-residue extract: Effects on quality and sensory attributes of cooked chicken meat

Sensory analysis, instrumental color, pH, and thiobarbituric acid reactive substances (TBARS) were determined on cooked chicken meat with and without grape seed extract during refrigerated storage. The effectiveness of extracts of winery grape residue from the grape varieties ‘Isabel’ and ‘Niagara’ were tested to evaluate their effectiveness at delaying lipid oxidation in cooked chicken meat and stored under refrigeration (4±1°C). The samples were aerobically and vacuum packaged and stored for 14 days. ‘Isabel’ grape extract (IGE) and ‘Niagara’ grape extract (NGE) proved effective at promoting oxidative stability when applied at concentrations of 40 or 60 mg of gallic acid equivalents (GAE)/kg, with results similar to the synthetic antioxidant butylated hydroxytoluene (BHT). The antioxidant efficiency of the extracts was highly dependent on the concentration used. The addition of grape-residue extracts combined with vacuum packaging proved to be a good method for increasing lipid stability in cooked chicken meat stored under refrigeration.