Yeast mannans protect liposomes against peroxidation but do not scavenge free radicals

► Mannans effectively protect liposomes against OH radicals. ► Mannans and glucans do not scavenge DPPH radicals. ► Protection is not caused by polysaccharides as scavengers of free radicals. ► Polysaccharides coat liposomes by strong nonspecific interactions. ► Coating shield protects liposomes against oxidation by OH radicals.