PHYSICOCHEMICAL CHARACTERIZATION AND MICROBIOLOGICAL QUALITY OF YACON (Smallanthus sonchifolius) FLOUR

Yacon (Smallanthus sonchifolius) has gained prominence as a functional food due to its high content of fructooligosaccharides (FOS), dietary fibers, and bioactive compounds associated with health benefits, such as prebiotic effects and glycemic control. The growing demand for alternative and nutritious ingredients in the food industry has driven the development of flours derived from this root, expanding its applicability in different formulations. In this context, the physicochemical characterization and microbiological evaluation of yacon flour are important steps to ensure its safety, stability, and industrial potential. This study aimed to evaluate the physicochemical composition and microbiological quality of yacon flour. Analyses of color, water activity (Aw), moisture, protein, lipid, and ash content were performed, in addition to microbiological tests for Escherichia coli and Salmonella. The flour showed a light color (L* = 65.4). The hue angle (Hue = 0.608 rad; ≈34.8°) indicated a predominance of yellowish to orange tones. These parameters suggest good visual appearance, although darker than traditional flours such as wheat and rice. This coloration may be associated with the presence of bioactive compounds and mild oxidative processes, highlighting the importance of controlling processing and storage steps. Regarding composition, yacon flour presented lipid content of 1.32% and protein content of 7.14%, higher than that of traditional flours, indicating its potential nutritional value. Ash content was 2.20%, within the range reported for tuber and root flours (1–4%), reflecting a moderate mineral fraction and providing nutrients such as potassium, calcium, and magnesium. Water activity (Aw) was 0.5438, a low value that ensures microbiological stability and extends shelf life by inhibiting the growth of most spoilage microorganisms. Moisture content was 9.84%, within the recommended limit for flours (maximum 15%). Microbiological analyses revealed the absence of Salmonella and Escherichia coli counts below the limits established by the Brazilian Health Regulatory Agency (ANVISA), Normative Instruction No. 313, September 4, 2024. Therefore, yacon flour showed satisfactory physicochemical composition, with low lipid content favorable to stability. In addition, low water activity and microbiological compliance reinforce its safety, supporting its potential as an ingredient for the development of functional foods and other food applications.