PROBIOTIC BEVERAGE BASED ON BRAZIL NUTS: PHYSICAL-CHEMICAL CHARACTERIZATION AND EVALUATION OF ANTIOXIDANT ACTIVITY

Brazil nuts (Bertolletia excelsa) are consumed raw, in the form of flour, drinks, ice cream, among others. The drink is commonly used due to its sensory, biological, and nutritional characteristics. Probiotics are microorganisms that promote various health benefits, modulating intestinal balance and contributing to the prevention of diseases associated with the gastrointestinal tract. The present study aims to develop and characterize a probiotic beverage from Brazil nuts. Brazil nuts were purchased from local stores (Santarém, PA, Brazil) and the Lactiplantibacillus plantarum Lp62 strain was provided by the State University of Santa Cruz (Ilhéus, BA, Brazil). The plant-based milk was prepared using Brazil nuts crushed in a domestic blender containing distilled water (75°C) in a 1:2 ratio (nuts:water), then filtered and pasteurized at 85°C for 10 minutes. For fermentation of the plant-based milk, the samples were inoculated with 10% (v/v) of the bacterial inoculum and incubated at 25°C for 24 hours. The fermented beverage (BF) and the fresh beverage (BN) were characterized in terms of acidity index, pH, total soluble solids, total polyphenols, total flavonoids, antioxidant activity by DPPH, and CFU/mL count. The acidity index value in BF was 5.19 ± 0.07, while BN presented 1.69 ± 0.12. The unfermented beverage had a pH of 6.79, and after fermentation, the pH decreased to 4.98. The total soluble solids values varied depending on sugar consumption during the fermentation process. The unfermented milk (BN) had 7 ± 0.04 °Brix, while after fermentation (BF) this value decreased to 0.87° ± 0.04 °Brix. The samples of unfermented (BN) and fermented (BF) Brazil nut milk did not contain flavonoids. Regarding total polyphenols, BN presented 132.215 ± 2.08 µg EAG/mg and BF showed 136.627 ± 1.27 µg EAG/mg. In determining antioxidant activity by the DPPH method, the values obtained were 125.8625 ± 2.62 µmol TEAC/mL for the BN sample and 131.5431 ± 2.13 µmol TEAC/mL for BF. The concentration of Lactiplantibacillus plantarum LP62 increased significantly during fermentation, from 5.51 log₁₀ CFU/mL in the BN sample to 9.51 log₁₀ CFU/mL in BF. Finally, fermented chestnut milk showed chemical and physicochemical characteristics valuable for a functional food.