Development of arrowroot flour fermented by kefir grains

The present study aims to produce arrowroot flour fermented by kefir grains, in addition to assessing the physicochemical, nutritional, and microbiological characteristics. Fermented arrowroot flour was produced at room temperature (approximately 25 to 28 °C). Fermentation was conducted in batch (6 kg of the substrate and 10% of kefir grains were added with homogenization every 3 hr). Samples were evaluated every 12 hr for both fermentation processes (fermentation process 1: 24 hr and fermentation process 2: 48 hr). The flours were evaluated for physicochemical, nutritional, and microbiological qualities, using a completely randomized design, considering only the variation in the duration of both fermentation processes (from 24 to 48 hr). The fermentation process positively modified the physicochemical, nutritional, and microbial characteristics of the flours. An increase in antioxidant activity (IC₅₀ : control flour [CF] = 18.9 ± 0.13; arrowroot kefir flour [24 hr of fermentation; AKF1] = 15.36 ± 0.14; and arrowroot kefir flour [48 hr of fermentation; AKF2] = 13.84 ± 0.15), protein percentage (CF = 3.08 ± 0.12; AKF1 = 4.87 ± 0.33; and AKF2 = 6.00 ± 0.07), and organic acid (lactic, acetic, and propionic acids) production was observed, as well as modification in color (browning), the conformation of starch structures, and carbohydrate reduction. These results suggested that the "arrowroot kefir flours" open a new perspective for introduction in the market as a new product that can be used as food in nature or food ingredient for making bread, biscuits, pasta, and others, showing microbiological safety and functions properties. PRACTICAL APPLICATION: The fermented flours present improved nutritional characteristics due to the fermentation process, such as higher antioxidant activity and protein levels. Regarding the population growth and societal demand for healthier food, one possibility is to provide a fermented flour with added nutritional value and raise knowledge about the arrowroot. Thus, these flours can be used in various food items or as an ingredient in food preparations for consumers that desire a healthy diet.

Keywords: Maranta arundinacea L.; fermentation; organic acids; phenolic compounds.