Impact of calcium-starch interactions on the textural and oil absorption properties of deep-fried potato mashes

Abstract

The quality of mashed potato-based deep-fried products largely depends on their texture and oil content. In this study, Laser Ablation Inductively Coupled Plasma Mass Spectrometry analysis revealed that CaCl2 addition to the water used for blanching increased the presence of Ca2+ ions in potato cell walls, in the middle lamellae as well as in the cells. Potato mashes were softer and had lower storage and loss moduli when the CaCl2 concentration was increased. Similar observations were made for potato starch gels, highlighting the importance of the interactions between Ca2+ ions and starch for the properties of potato mashes. Interestingly, more amylose was extracted from potato starch gels when the system contained more CaCl2 due to increased amylose leaching from the granules and impaired crystallization. In contrast, amylopectin extraction yields were hardly affected. It is suggested that in potato mashes, the presence of more extracellular amylose with lower crystallinity changed the textural and rheological properties when CaCl2 was added to the blanching water. Additionally, Time Domain Proton Nuclear Magnetic Resonance revealed more and stronger interactions between starch and water in potato mashes due to Ca2+ ions cross-linking amylopectin. These stronger interactions are believed to contribute to the observed reduced oil absorption during deep-frying. Hence, CaCl2 addition during blanching can impact the quality of deep-fried potato mashes and holds promise to optimize the manufacture of frozen potato products.