Kombucha is a functional beverage that lacks studies toward standardization of process parameters; thus, the present work aims to evaluate the effect of sucrose content, initial SCOBY mass, and tea composition on several characteristics of the final beverage. For this purpose, a factorial design was performed, and the effect of the three variables was statistically evaluated. All kombuchas were within Brazilian regulation standards (higher than 2.5 and lower than 130 mgEq/L) and can be classified as non-alcoholic beverages. Kombucha yield ranged from 87.3% to 96.4%; SCOBY growth, from 41.11 to 62.08%; turbidity, from 108 to 421.5 NTU; acetic acid, from 3.78 to 5.33 mg/mL; glycerol, from 0.25 to 0.52 mg/mL; and ethanol content, from 1.90 to 3.21 mg/mL. Results showed that kombucha yield, pH, and SCOBY growth were significantly influenced by the SCOBY mass; acidity was greatly affected by the tea composition; kombucha’s turbidity was significantly affected by the sucrose content and the interaction of the sugar content and tea composition; and glycerol, alcohol, and acetic acid were not affected by the parameters evaluated. Results bring science-based information about this global trending beverage, seeking high quality and standardization.

The production of polyhydroxyalkanoates (PHAs) by Bacillus megaterium using industrial residues, crude glycerol from biodiesel synthesis and rice hull hydrolysate (RHH), as low-cost carbon sources was investigated. The experiments were conducted by shaking flasks at 30 °C and 180 rpm up to 72 h. The extraction of PHA was carried out using sodium hypochlorite to make its recovery more environmentally friendly by avoiding organic solvents (chloroform). The yields of PHA varied depending on the extraction method. A total of 33.3% (w·w⁻¹) (mixing chloroform: sodium hypochlorite) and 52.5% (w·w⁻¹) (sodium hypochlorite only) were obtained using glycerol and glucose as a carbon source, respectively. Preliminary experiments using RHH as a carbon source Indicated a yield of PHA of 11% (w·w⁻¹) (chloroform). The PHA produced had thermal properties, such as transition temperature, similar to the commercial polyhydroxybutyrate (PHB).

Gluten-free products and non-alcoholic beverages have become popular global trends. This study assessed strategies for producing low-alcoholic and low or gluten-free beers. Barley malts were fermented by Saccharomyces cerevisiae or Saccharomycodes ludwigii, and commercial endopeptidase was used to reduce gluten. S. cerevisiae is the most used yeast in alcoholic beer, so vacuum evaporation was used to reduce values of ethanol. S. ludwigii produces less alcohol, however, there was no data reported it would ferment on a semi-industrial scale. The physiochemical parameters in rice malt beers were similar to both yeasts. However, the parameters found differed for beer with barley malt mainly ethanol values, confirming the fermentative difference by tested strains. Volatile composition was evaluated and analyzed by multivariate analysis. The beers proposed by different methodologies: S. cerevisiae with barley malt, peptidase, and evaporation exhibited aromas of floral and featuring beer and spice notes, among others; S. ludwigii fermentation with barley malt and peptidase showcased aromas rich in floral and fresh accents, among others; and, S. cerevisiae with malted rice exhibited notes evoking fruity notes reminiscent of roses and S. ludwigii using malted rice was associated with aromas featuring fruity attributes and emitting rancid notes, among others. Among all the strategies tested, the one using barley malt, enzyme, and S. cerevisiae proved results in terms of aromatic parameters, even with the final boiling process to remove the alcohol.