Revolutionizing Gluten-Free Baking: the Role of Cassava Sour Starch in Specialty Breads

Abstract Cassava starch (CS) possesses unique attributes such as mild flavor, bright white color, distinctive rheological behavior, and pasting properties, making it a key ingredient in diverse food applications. As the second-most demanded starch globally, CS is primarily produced in tropical and subtropical regions, with Brazil being a leading producer. A specific type of cassava starch, known as polvilho azedo in Brazil (almidón agrio in Colombia), is traditionally made using natural fermentation and sun drying. This culturally significant starch is essential for gluten-free bread production. This study analyzed eight commercial samples of polvilho azedo (PA) and one native CS sample to evaluate key characteristics, including color, acidity, organic acid content, pasting behavior, rheological and thermal properties, morphological structure, swelling, solubility, syneresis, and baking performance. Results revealed notable variability in product quality. Three of the eight samples were likely industrially processed, showing the lowest acidity (1.53 mL NaOH100g-1), organic acid content (607.1 mgkg-1), and b* values (1.84), alongside the highest L* values (>95.2). The lack of specific Brazilian regulations for PA has allowed chemically modified starches to be marketed as traditional PA, potentially misleading consumers and compromising product authenticity. This highlights the need for clear standards to protect the integrity of this unique product.