Assessment of agave fructans as lyoprotectants of bovine plasma proteins concentrated by ultrafiltration

The effectiveness of fructans as protectant agent to prevent protein denaturation was evaluated during freeze-drying and storage. Native agave fructans and two fractions obtained by ultrafiltration were assessed as protective agents. Since the protein denaturation during freeze-drying can alter the functional properties of proteins, the evaluation of bovine plasma protein properties was performed with different concentration of fructans, pH and freezing temperatures. The results showed that the incorporation of fructans as lyoprotectants improved functional properties, due to the reduction of protein denaturation with maximum stabilization of plasma bovine protein at a fructan concentration between 5% and 10% (w/v) for native fructans and 10% (w/v) for the fractions of fructans at −40°C. Moreover, when freezing at −4°C, fructans fraction at 15% (w/v) prevented protein denaturation while native fructans exerted no acceptable protection (P