Short-chain fructooligosaccharides synthesis using a commercial enzyme complex from Aspergillus sp. and anti-cancer activity on HCT116 and HT-29 cell lines

Abstract

Over the last years, short-chain fructooligosaccharides (FOS) have gained significant attention as valuable food and dietary supplement components. Apart from implications such as dietary fibres, sweeteners, and humectants, FOS are hailed for their prebiotic properties. Moreover, much research is dedicated to their role as anti-cancer agents. Despite the ongoing interest, both technical aspects, challenges of FOS production, and their anti-cancer role necessitate more in-depth investigations to understand their healthcare role better. This study aimed to optimise critical FOS synthesis parameters using a commercial enzyme, Viscozyme® L, to obtain a preparation with a high FOS content. A central composite design and response surface methodology evaluated the effect of pH, temperature, synthesis time, substrate, and enzyme load on multiple responses, chosen as independent variables, were utilised to define optimal conditions. Under the optimal conditions (temperature 50 °C, pH 5.5, sucrose concentration 352 g/L, enzyme concentration 2.5% v/v, and 5.5 h of reaction), a preparation with a total FOS content of 58.8% was obtained. The FOS preparation showed minimal in vitro antioxidant capacity in the ORAC, CUPRAC, and ABTS*+assays. In addition, the cytotoxicity of FOS against tested cell lines was evaluated. FOS did not reduce HT-29 cell viability even at the concentration of 2.5 mg/mL, whereas FOS inhibited the proliferation of HCT116 cells by 50% at 2.35 mg/mL. Finally, the sensitisation effect of FOS on HCT116 cell treatment with doxorubicin has been revealed.