Nutritional quality of protein concentrates from Moringa Oleifera leaves and in vitro digestibility.

The nutritional value and digestibility of leaf proteins is still a major issue. Therefore, the goal of this work was to optimize the production of a protein concentrate (PC) from Moringa Oleifera defatted leaves (MODL) by enzymatic extraction using Viscozyme L and evaluate its nutritional quality and digestibility. Protein extraction conditions were screened using a factorial design. Enzyme/Substrate ratio and pH had no significant effect, whereas, the significant variables, temperature (°C), enzyme concentration and incubation time (h) were optimized by central composite design (CCD). PC contained 55.7% of proteins with a balanced amino acid profile when compared with MODL and higher content of essential amino acids (EAAs) (488.6-402.9 mg/g of protein respectively). Improvement on protein digestibility was observed for MODL compared to PC (64.75-99.86% respectively) and higher protein digestibility corrected amino acid score (PDCAAS) (62.10-91.41% respectively). PC meets FAO protein quality expectations.

Inhibitory effect of vinegars on the formation of polycyclic aromatic hydrocarbons in charcoal-grilled pork.

The effect of five different vinegars, applied as a seasoning, on the formation of polycyclic aromatic hydrocarbons (PAH) in charcoal-grilled pork loin was investigated. PAH were assayed using acetonitrile based-extraction and high-performance liquid chromatography with fluorescence detection. Unseasoned samples presented a mean value of 31.47 ng g-1 of PAH4 (sum of benz[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene), near the maximum established by European Union (30 ng g-1). Significant reduction (p < .05) of PAH4 formation was observed in meat samples sprayed with vinegar. Elderberry vinegar exhibited the highest inhibition (82%), followed by white wine vinegar (79%), red wine and cider vinegars (66%), and fruit vinegar with raspberry juice (55%). The total phenolic content and antioxidant activities of vinegars had a moderate negative correlation with PAH4 formation, and 3rd degree polynomial equations had the best fitting performance to explain this relation. Spraying meat with these vinegars prior grill is an easy-to-apply strategy to limit the exposure to PAH.