Evaluating the effects of insoluble date fruit (Phoenix dactylifera L.) fibers on meat analogue patties composed of pea and wheat protein isolates

This study aimed to evaluate the effects of date pomace fibers (DF) on the physicochemical properties of plant-based ground patty analogues. Previously optimized pea and wheat protein isolates were incorporated with varying concentrations of DF, i.e., 0 %, 2.5 %, 5 %, 7.5 %, and 10 % w/w. The addition of DF increased water retention in the patties, leading to subsequent changes in the patty structure. Frequency sweep results confirmed that the presence of DF contributed to structural stability, where patties exhibited more solid-like characteristics and stronger internal bonds, which also increased hardness from ∼65 g to 160-175 g. This could positively correlate with the brittleness of the patties, where large deformation results showed that high DF formulations were more brittle, which reduced springiness, as evident in DF7.5 (from ∼2 mm in DF0 to 1.89 mm in DF7.5). The microstructure revealed that high DF content increased patty fibrousness and led to a uniform structure. Therefore, high DF concentrations seemed to positively impact the analogue structure. DF also contributed to patty analogue color by imparting brown-red tones which may result in a closer appearance to conventional beef patties. This study establishes a foundation for further studies to be conducted on determining the optimum DF concentration that yields patty analogues with desirable structure as well as appearance.