Desenvolvimento de farinha de araruta fermentada por grãos de kefir

Abstract

Fermentations of raw materials by microbial action are essential for the production of metabolites with functional properties and are exploited for the development of new fermented foods to improve their nutritional value. Arrowroot (Maranta arundinaceaea L.) is a perennial herbaceous plant originating from tropical regions of South America, including Central Brazil, commonly used as an ingredient in the production of bread and biscuits, because gives lightness and improves the texture of products. Besides these characteristics, the araruta presents approximately 45% of inulin, indicating to be a natural font with prebiotic potential. Kefir is a symbiotic culture of microorganisms such as yeasts, lactic and acetic bacteria that aggregate nutrition value to a fermented product. Currently, several researchers have been conducted with kefir grains using non-dairy raw materials, to improve the nutritional value of food. The present study aimed to evaluate the fermented effect of kefir grains in the substrate of arrowroot evaluating the possible physicochemical and nutritional characteristics added to conventional araruta flour. The control flour (CF) and fermented (fermented flour for 24 hours (AKF1) and 48 hours (AKF2) at room temperature (~25-28oC)) were produced. Fermentation was conducted in underwent batch (approximately six liters of substrate added of 10% of kefir grains, with homogenization every 3 hours), where the parameters for control were: hydrogenic potential (pH), temperature and total titratable acidity. Samples were evaluated every 12 hours in both fermentation processes (24 and 48 hours). The flour CF, AKF1, and AKF2 were evaluated for features physicochemical nutritional and microbiological quality, using a randomized design, with three repetitions and using the Tukey test with a 5% of the significance level. Has been verified increase in total titratable acidity of 0,63 to 1,2 and 1,55meq NaOH.100g-1 (CF, AKF1 and AKF2, respectively). Phenolic compounds showed a significant increase in 226,19 to 246 and 256,02 mgGAE.100g-1

, and a decrease of IC50 of 18,9 to 15,36 and 13,84, both in CF, AKF1, and AKF2, in this order. Has been verified increase in protein contents (3,08 to 4,87 and 6%) and decrease in carbohydrates (81,3 to 79,39 and 78,04%), for CF, AKF1, and AKF2, respectively. Amylose showed a decrease of 36,37% (CF) to 28,5% (AKF1), unable to verify the presence of this compound in AKF2. Glucose and fructose has been verified in CF (9 and 14mg/g, respectively), with significant decrease in AKF1 (of 0,29 and 0,32mg/g for 0,05 and 0,14 mg/g, respectively) and absence of same in AKF2. It was identified lactic, malic, acetic and propionic acids in flours AKF1 and AKF2, reaching values of 0,051, 0,065, 0,074 g/g (AKF1) and 0,038, 0,076, 0,07 g/g (AKF2), respectively. The flours (CF, AKF1, and AKF2) showed satisfactory microbiological quality, indicative of safety for consumers. The flours (AKF 1 and AKF2) produced in this study open a new perspective for an introduce in the market as a new product, being able use as food in natura and/or food ingredient for the elaboration of breads, biscuits, pasta, and others, showing microbiological safety and functions properties.