Further insights into the role of melanoidins on the antioxidant potential of barley malt.

The role of Maillard reaction products isolated from barley malt by gel permeation chromatography and ultrafiltration on the antioxidant potential of pale, melano80 and black malts was evaluated. The roasting process is responsible for the polymerisation of early formed lower molecular weight compounds (<10 kDa) into high molecular weight melanoidins (>300 kDa). Melanoidins showed 3-fold higher capacity to scavenge radicals than the lower molecular weight colorants by the metmyoglobin assay. However, a significant decrease of the capacity of black malt and high molecular weight melanoidins to inhibit Fenton induced hydroxyl degradation of deoxyribose was observed. As the high molecular weight fraction, isolated from the black malt extract, exhibited 4-fold higher reducing power than the lower molecular weight fraction, our results support a pro-oxidant effect due to the catalytic formation of hydroxyl radicals in the presence of ferric ions.

Metabolomic prediction of pregnancy viability in superovulated cattle embryos and recipients with fourier transform infrared spectroscopy.

We analyzed embryo culture medium (CM) and recipient blood plasma using Fourier transform infrared spectroscopy (FTIR) metabolomics to identify spectral models predictive of pregnancy outcome. Embryos collected on Day 6 from superovulated cows in 2 countries were individually cultured in synthetic oviduct fluid medium with BSA for 24 h before embryo transfer. Spent CM, blank controls, and plasma samples (Day 0 and Day 7) were evaluated using FTIR. The spectra obtained were analyzed. The discrimination capability of the classifiers was assessed for accuracy, sensitivity (pregnancy), specificity (nonpregnancy), and area under the ROC curve (AUC). Endpoints considered were Day 60 pregnancy and birth. High AUC was obtained for Day 60 pregnancy in CM within individual laboratories (France AUC = 0.751 ± 0.039, Spain AUC = 0.718 ± 0.024), while cumulative data decreased the AUC (AUC = 0.604 ± 0.029). Predictions for CM at birth were lower than Day 60 pregnancy. Predictions with plasma at birth improved cumulative over individual results (Day 0: France AUC = 0.690 ± 0.044; Spain AUC < 0.55; cumulative AUC = 0.747 ± 0.032). Plasma generally predicted pregnancy and birth better than CM. These first results show that FTIR metabolomics could allow the identification of embryos and recipients with improved pregnancy viability, which may contribute to increasing the efficiency of selection schemes based on ET.