INFLUENCE OF PROCESSING ON BIOACTIVE COMPOUNDS OF A FERMENTED CHICKPEA FLOUR PLANT-BASED BEVERAGE

Plant-based beverages are an alternative for consumers who avoid dairy products or have milk allergy or lactose intolerance. Therefore, chickpeas are a promising alternative, containing approximately 25% protein and, when used in fermented beverages, can serve as a carrier of probiotic microorganisms while providing prebiotic compounds that contribute to gut health. The aim of this study was to monitor the changes in total phenolic content and antioxidant activity of a fermented chickpea beverage throughout the processing and storage stages. The samples evaluated were the chickpea flour, the fermented beverage on day 0, and after 63 days of storage, in order to understand how heat treatment and fermentation affect these compounds. Chickpea flour was first produced, then mixed with water, modified starch and sucralose as a sweetener. Subsequently, the beverage was pasteurized at 80 ºC for 10 minutes, cooled to 42 ºC and inoculated with a commercial starter culture containing Bifidobacterium spp., Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus paracasei and Streptococcus thermophilus until the pH reached 4.6. Thereafter, potassium sorbate was added as a preservative, and the beverage was stored under refrigeration at 4 ºC. The total phenolic content was determined using the Folin–Ciocalteu method and expressed as milligrams of gallic acid equivalents (GAE) per 100 grams of beverage. The antioxidant activity was measured using the ABTS method and expressed as micromoles per gram. For both analysis, absorbance was measured using a UV–Vis spectrophotometer. Total phenolic compounds showed similar values between the flour (49.17 mgEAG/100g) and the fermented beverage on day 0 (48.87 mgEAG/100g), but increased by 10.5% after 63 days of storage, reaching 54.03 mgEAG/100g. This increase can be explained by the release of phenolic compounds previously bound to the matrix as a result of fermentation. In contrast, antioxidant activity decreased sharply after heat treatment, falling from 2.57 μmol/g in the flour to 0.19 μmol/g on day 0. During storage, a recovery in antioxidant activity was observed, reaching 0.30 μmol/g on day 63, although this value remained 88.3% lower than that observed in the flour. These results suggest that thermal processing reduced antioxidant activity, while fermentation and storage may have promoted the release or formation of compounds with antioxidant activity, contributing to its partial recovery. Although heat treatment is necessary to ensure the microbiological safety of the beverage, it reduces antioxidant activity; therefore, fermentation represents a promising step to partially mitigate these losses, while maintaining phenolic compounds during storage. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001 and also by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) – Process No. 198382/2025-1.