**Preface**

Polysaccharides, starch, protein, pectin, and fibre are naturally occurring polymers with efficient, safe, and green characteristics. These food components show different physico-chemical properties, functional properties, and biological activity, and these natural components have broad application prospects in food processing. Therefore, research on the modification and application of polysaccharides, starch, protein, pectin, and fibre is needed. Our Special Issue, "Research on the Properties of Polysaccharides, Starch, Protein, Pectin, and Fibre in Food Processing", with four reviews and thirty articles, is an attempt to provide a broad perspective on the recent in-depth study of these components. The Guest Editors are very grateful to all the authors for their contributions, and the entire MDPI team for their professional support.
