The quantification of hydrolysable polyphenols such as gallic, ellagic acid and vescalagin by HPLC-DAD is classically run after methanol extraction as a reference solvent. Water extraction is usually discarded because of a lower obtention of total polyphenol content compared to methanol extraction. In our study, methanol was compared to water extraction in both the total polyphenol content method and the HPLC-DAD analysis. Total polyphenol content in water extraction was lower than in methanol extraction, but water extraction gave better results on HPLC-DAD. In conclusion, total polyphenol content cannot be used as reference to choose the solvent of extraction to quantify some polyphenols by HPLC-DAD because of the specific properties of each polyphenol. Indeed, recovery results obtained on hydrolysable polyphenols with water extraction were better and with a lower variability than following methanol extraction.

With increasing meat demand and global warming, the sustainability of broiler chicken production has become a “hot topic” for the conventional industry. We conducted a life cycle assessment (LCA) to compare the environmental impact of supplementing broiler chicken diets with postbiotics derived from the yeast cell wall (YCW). Supplementation with S. cerevisiae reduced the carbon footprint of climate change (8.4%), land use (8.7%), water use (7.7%), resource use (7.9%), acidification (12.5%), marine eutrophication (9.5%), freshwater eutrophication (8.6%), terrestrial eutrophication (12.6%), and particulate matter (11.4%). The positive effects on the environmental impact were associated with improvement in the feed conversion ratio (FCR: −7.6%), body weight gain (BWG: +5.7%) and a reduction in mortality of around 44.1%. Overall, the environmental benefit was similar in chickens exposed to heat stress (−8.7%) or challenged with Clostridium perfringens (−8.2%), two stressful situations commonly encountered on poultry farms. This LCA study demonstrates that S. cerevisiae is a food additive that can help the poultry industry cope with stress caused by various factors and reduce its overall environmental impact.