Thermal transitions and microstructure of starch-apple pomace-based systems

ROCHA PARRA AF; BARRERA, GABRIELA N.; RIBOTTA PD; FERRERO, CRISTINA

INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2023

0950-5423

Apple pomace (AP) is the by-product obtained after juice extraction. It is a potential ingredient for fiber enrichment of foods. In the present work, AP was combined in gluten free-mixtures with rice flour (RF), cassava starch (CS), egg white (EW) and sucrose (SR) to analyze its effect on thermal transitions of starch and the batter and bread crumb microstructures. Model systems with all or part of the main ingredients (RF:CS:EW:AP:SR in 4:4:1:1:1 proportions) and a batter formulation with AP were prepared by dry mixing and then dispersing the solids in water. CLSM allowed observing the distribution of egg proteins, AP and RF particles and CS granules. The batter enriched with AP exhibited higher apparent viscosities and dilatant behavior. Thermal transitions were analyzed by DSC. Endotherms ranged between 57 and 97 °C. Gluten-free breads microstructure was analyzed by SEM. A more irregular and compact crumb structure was observed when AP was used, with the air cell walls constituted by gelatinized starch granules and AP particles interpenetrating them. By measuring firmness of crumb along storage, it could be concluded that amylopectin retrogradation was partially inhibited by the presence of AP in model systems but in bread this inhibiting effect was not evident.