Native tapioca starch as a potential thickener for fruit fillings. Evaluation of mixed models containing low-methoxyl pectin

Fruit fillings for pastries are low-pH systems that have to withstand baking temperatures without loss of quality. The present study evaluated a mixed system based on native tapioca starch (NTS) with the addition of low-methoxyl pectin (LMP) as a model for use in an acid environment (pH 3.0–3.2). This system was compared with a modified (highly cross-linked, hydroxypropylated and phosphated) waxy corn starch (MWCS) commonly used in industrial fruit fillings. The starch pasting and viscoelastic properties, instrumental texture and syneresis were measured. The addition of LMP to replace 10% of the NTS significantly increased the peak viscosity (PV), hot paste viscosity (HPV), cold paste viscosity (CPV) and total relative setback of the NTS and reduced relative breakdown. The mixed system also made the gel stronger and more elastic, achieving similar levels of viscoelastic properties to those of the control starch. At a frequency of 1 Hz, in acid conditions and with 35% sugar, no significant differences in G′, G″ and tan G′/G″ were found between the mixed system and the control (MWCS). The addition of pectin caused a significant increase in the firmness and consistency of the gels analyzed by extrusion tests.