The invention relates to a process for the production of expanded foam beads made of pellets comprising a polyester mixture composed of: a) from 50 to 99% by weight, based on components a and b, of a biodegradable polyester based on aliphatic or aliphatic and aromatic dicarboxylic acids and aliphatic diols, and b) from 1 to 50% by weight, based on components a and b, of polylactic acid, comprising the following steps: (i) production of a suspension comprising pellets of the polyester mixture in a suspension medium, (ii) impregnation of the pellets comprised in the suspension from step (i) with at least one physical or chemical blowing agent, in order to obtain blowing-agent-loaded pellets in suspension, by heating the mixture to the depressurization temperature IMT, with stirring, and (iii) after expiry of a retention time, depressurization of the suspension obtained in step (ii), in order to obtain expanded foam beads, which comprises proceeding in an aqueous suspension medium, adding the blowing agent in step (i) or in step (ii) during the heating phase or immediately after the heating phase and, in step (ii), after heating, keeping the suspension for from 3 to 100 minutes at a temperature in the range from IMT minus 5 DEG C to IMT plus 2 DEG C. The invention further relates to expanded foam beads obtainable by said process, and also to the production of moldings from said foam beads.