Alternative Plant-Based Gluten-Free Sourdough Pastry Snack Production by Using Beetroot and Legumes: Characterization of Physical and Sensorial Attributes

Objective of this study was to design a formula of a sourdough pastry snack by adding starter inoculum into the formulation which was obtained by the fermentation process through beetroot (Beta vulgaris) puree with black-eyed pea (Vigna unguiculata) and fava bean (Vicia faba). With this development process, it was aimed to review the functional impact of legumes as gluten replacement and emphasize the importance regarding physical and sensory attributes in a pastry snack product. First, a starter inoculum was developed based on modification of the shalgam fermentation process with legumes. An experimental design suggested by the response surface methodology was used to optimize its microbial properties and level of antioxidants with the factors of amounts of beetroot puree, fava bean/black-eyed pea ratio, and fermentation time. In the second part, this starter inoculum was mixed with fava bean flour to obtain a sourdough pastry snack (FBS) with improved physical and sensory attributes and compared to the wheat control sourdough (WCS) pastry snack after the baking process. According to the optimization results to produce starter inoculum with the optimum results of lactic acid bacteria 9.55 log cfu/mL, the level of antioxidant activity 91.86 μM TE/mL, and total yeast level 6.96 log cfu/mL; 75 mL of beetroot puree, 100% for fava bean, and fermentation for 24 h were obtained. Compared to WCS, FBS has approximately 16% higher hardness values. Also, a significant difference was observed for stiffness and springiness among samples. The retention of moisture was higher in the first 4 days following the storage for 8 days; the moisture content continuously decreased with the final moisture content of 12.6%. When compared with the results of textural profile analysis in terms of hardness, stiffness, and springiness, sensory results were correlated. Comparing the overall acceptability of the FBS to WCS, FBS was from moderate to higher scores, which indicated that it could be a promising alternative to chemically developed snack products and a preferred product for people suffering from celiac disease and other gluten intolerances.