YERBA MATE INFUSION KOMBUCHA: EVALUATION OF CARBOHYDRATE SOURCES’ INFLUENCE ON PHYSICOCHEMICAL AND SENSORIAL CHARACTERISTICS

Kombucha is the beverage produced by fermenting infusions sweetened by a symbiosis of yeast and acetic acid bacteria, rich in bioactive compounds due to the black tea and green tea based. This study aimed to develop a yerba mate (Ilex paraguariensis) kombucha with different carbohydrate sources, such as table sugar (sucrose), sugarcane molasses, and three kinds of honey: Apis (Apis melifera), Borá (Tetragona clavipes), and Mandaguari (Scaptotrigona postica). In a 13 g/L of I. paraguariensis infusion 24 g of an activated commercial starter culture and 20 %(v/v) of the activation fermented were added, and also the carbohydrate sources. On the fermentation days 0, 5, 10, 15, and 20 the pH, total acidity, soluble solids, soluble proteins, and total phenolic compounds of the kombucha was analyzed. The High-Pressure Liquid Chromatography was used to determine caffeine, chlorogenic acids (3-CQA, 5-CQA, 4-CQA, 3,4-CQA, 3,5-DQA, and 4,5-DQA), and rutin, the main phenolic compounds of I. paraguariensis. After 20 days of the fermentation, it was also performed a sensorial analysis of the appearance, aroma, taste, color, and overall assessment, based on a nine-point hedonic scale, and purchase intention, based on a five-point scale. After 20 days of fermentation, the Apis honey kombucha had lower pH 2,82±0,01 and lower total acidity 146,17±2,02 meq/L. On the other hand, the molasses kombucha had higher pH 3,32±0,02 and total acidity 235,00±1,00 meq/L. These results indicate the presence of different acids concentration in each kombucha, with different pH values. The soluble solids indicate the carbon sources' consumption and can represent the production of metabolites during fermentation. Although, after the fermentation lower soluble solids in the molasses kombucha with 7,67±0,06 °Brix, and higher soluble proteins (0,41±0,06 mg/mL) and reducing sugars (22,49±0,10 g/L). These indicate the potential to increase the starter culture metabolic activity. The molasses kombucha presents the higher total phenolic compounds content after 20 days of fermentation (60,87±1,67 μg of gallic acid/mL), and the Mandaguari honey shows the lower (48,01±2,92 μg of gallic acid/mL). These indicate the interaction of the carbon sources with the phenolic compounds. 5-CQA, 3-CQA, and 4-CQA are the three most abundant compounds in every kombucha sample. These compounds are well known in high concentrations in the yerba mate composition. The higher amount of these compounds after the 20 days of fermentation rather than on the first days indicates the concentration of the compounds in the product during the fermentation. Kombucha beverages sensorial analysis results of color and appearance with scores around 7. The taste and aroma of Apis honey and sucrose-kombuchas were the most accepted. Overall assessment and purchase intention results indicate the acceptance of all honey samples except the Mandaguari and no purchase intention for the molasses sugarcane sample. It is essential to know that different carbohydrate sources results in different sensory products. Therefore, changing the carbohydrate source makes the kombucha production suitable for the best offers of raw materials and can lead it to new sensory attributes.