Effect of endogenous and exogenous enzymatic treatment of green vanilla beans on extraction of vanillin and main aromatic compounds.

Endogenous and exogenous enzymatic hydrolysis carried out to obtain vanilla extracts with higher concentrations of vanillin using green vanilla beans. Sequences initiated with freezing of green vanilla beans at - 1 °C for 24 h, followed by endogenous hydrolysis under optimal ß-glucosidase activity at 4.2 and 35 °C for 96 h, exogenous hydrolysis with Crystalzyme PML-MX at pH 5.0 and 40 °C for 72 h, and ethanol extraction at 40% (v v-1) for 30 days. In the proposed method, 200 g of fresh green vanilla beans with 84% moisture (32 g dry base) were used to obtain a liter of single fold vanilla extract. This method allowed the release of 82.57% of the theoretically available vanillin from its precursor glucovanillin with 5.78 g 100 g-1 green vanilla beans (dry base). Vanillic acid, p-hydroxybenzaldehyde and vanillyl alcohol were also released and found in commercial and enzymatic extracts. Glucovanillin was detected in commercial and traditional extracts but was absent in enzymatic extracts, indicating incomplete hydrolysis during the curing process. An in vitro assay was conducted to determine if the presence of peroxidase during hydrolysis might affect overall vanillin concentration. Results showed that POD can use vanillin as a substrate under conditions similar to those in which hydrolysis was conducted (pH 5.0 and 50 °C), possibly explaining why vanillin concentration was not complete at the end of the process.

Human health risk of dietary intake of organochlorine pesticide residues in bovine meat and tissues from Veracruz, México.

Tissue distribution patterns of organochlorine pesticides in bovine carcasses varied significantly among seasons, geographic locations and tissues. The highest concentrations of Σ-DDT during the dry season were detected in lungs from Paso de Ovejas (2,834.90µg/kg lipid) and, during the rainy season, Lindane and Σ-HCH in muscle and lung samples from Paso de Ovejas (995.80 and 1,690.10µg/kg lipid). Estimated daily intakes of γ-HCH and Σ-DDT (3.35 and 1.22µg/kg bw/day) through consumption of muscle tissues from Paso de Ovejas and Puente Nacional during the rainy season showed the highest contribution. During the rainy season the highest non-cancer Hazard Ratios estimated corresponded to γ-HCH (3.97) and Σ-DDT (4.39) detected in muscle samples from Puente Nacional. The highest Hazard Ratios of cancer risk to the 95th centile daily consumption through meat corresponded to p,p'-DDT from Alvarado (7.76E+06) and from Paso de Ovejas for γ-HCH (1.50E+05) during rainy season. The results indicate potential non- and carcinogenic risks to consumer health through meat consumption.

Effect of coumaphos on cholinesterase activity, hematology, and biochemical blood parameters of bovines in tropical regions of Mexico.

To assess the effect of coumaphos [O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl) O,O-diethyl phosphorothioate] exposure on physiological responses during bovine production, acetylcolinesterase (AChE) and butyrylcholinesterase (BuChE) activities were measured in whole blood, erythrocytes, and plasma of healthy male steers (Bos Taurus x Bos indicus) sprayed with coumaphos at a non-lethal dose of 1 mg kg(- 1) body weight per day once every 14 (in vivo group) or 21 days (southern and central groups). Coumaphos topically administered at 1 mg/kg body weight per day to cattle under normal management practices in tropical areas produced a significant inhibition in erythrocyte (RBC) AChE and BuAChE activities when compared to baseline levels. RBC-AChE activity for the in vivo group decreased 71.3% (P < 0.05) and BuChE activity 59.1% (P < 0.05); RBC-AChE activity decreased 55.1% (P < 0.05) (southern group) and 43.4% (P < 0.05) (central group). Compared to the control specimens, steers from in vivo, southern, and central groups after 150 days of exposure had lower (P < 0.05) leukocyte count, absolute lymphocyte, erythrocyte, and platelet counts. Decreases in RBC-AChE activities correlated with decreased lymphocyte (r = 1.000, p = 0.01), erythrocyte (r = 1.000, p = 0.003), and platelet counts (r = 0.841, p = 0.036). Significantly increased BUN levels (P < 0.05) correlated with the decrease in RBC-AChE activities (r = - 0.997, p = 0.047) and with the decrease in absolute red blood cell (r = - 0.883, p = 0.020) and lymphocyte (r = - 0.825, p = 0.043) counts; increased (P < 0.05) total plasma protein levels correlated with the decrease in RBC-AChE activities (r = -0.998, p = 0.043), absolute red blood cell (r = - 0.998, p = 0.040), lymphocyte (r = - 0.893, p = 0.017), and platelet (r = -0.855, p = 0.030) counts. The physiological responses correlated with the erythrocyte acetylcholinesterase inhibition could be considered as early indicators or warning responses of bovine exposures to organophosphorus pesticides (OPs).

Sensory properties changes of fortified nixtamalized corn flour with lysine and tryptophan during storage.

This study was conducted to determine sensory changes of fortified nixtamalized corn flour with lysine and tryptophan up to 83, 100, and 150% of suggested FAO pattern after 2 months storage at room temperature (30 degrees C). Totally, 16 trained panelists participated in sensory study of tortilla made of enriched and normal corn flours where six attributes and a total of 19 descriptors were taken into consideration. A reflectance colorimeter was also used in determination of changes in tortilla color parameters. No significant differences were found in the analysis of 19 descriptors of tortilla made of enriched and normal nixtamalized corn flour after 2 months storage. Also, no color parameter changes were found between normal and enriched tortillas.