Bioprocess development for fructooligosaccharides and carotenoids production using Agave mead

Abstract

Fructooligosaccharides (FOS) and carotenoids are bioactive compounds of interest to the food industry due to the multiple benefits associated with their daily intake. One of the strategies that can be used to obtain said products of interest is successive fermentation, in which a compound of interest is produced in an initial fermentation, and the same resulting medium can be used to be fermented by another microorganism to generate another metabolite of interest. The successive fermentation strategy was used to produce FOS (first fermentation) and carotenoids (successive fermentation) using Agave mead as fermentation media. First, fermentation was evaluated for 120 h to determine the best fermentation time in terms of FOS productivity (g FOS/L*h) and carotenoids (mg/L*h). Once the best fermentation time was selected, the effect of different variables was evaluated. A Box Hunter & Hunter experimental design was used, considering five independent variables (pH, inoculum concentration, agitation, temperature, and light) at two levels (−1, +1) that influence total FOS (g/L) and total carotenoids (mg/L). Selected variables were later evaluated in a third-order experimental design (Box Behnken) to optimize total FOS (g/L) and total carotenoids (mg/L) in successive fermentation. As a result, it was possible to take advantage of the sugars present in the Agave mead to produce FOS and successively carotenoids in the same fermentation medium. In addition, through the experimental design, it was possible to obtain a concentration of 33.33 ± 1.39 g/L of total FOS and 5.11 ± 0.25 mg/L of total carotenoids in 48 h of fermentation.