Assessment of enzymatic complexes for the in situ production of prebiotic fructo-oligosaccharides in a strawberry preparation for dairy industry applications

The increasing demand for healthier food products has prompted the food industry to seek innovative production methods. Fructo-oligosaccharides (FOS), valued for their prebiotic properties, have been incorporated into various foods. This study explores a novel approach involving the conversion of sucrose from strawberry preparations into FOS in situ. Four commercial enzyme blends, Viscozyme® L, Pectinex® Ultra SP-L, Catazyme® 25 L, and Novozym® 960, were assessed. Novozym® exhibited the highest transferase activity (12.506 ± 0.053 U·mL−1), and under optimal reaction conditions (47.4°C, pH 5.4, enzyme-to-substrate ratio of 1:99 v/v) produced a total FOS yield of 0.646 ± 0.006 gFOS·ginital sucrose −1 after a 1.25-hour reaction. The industrial potential of this in situ process was demonstrated in a 1.5 L bioreactor, yielding a strawberry preparation containing 56.3% w/w prebiotic FOS, with an 85.4% reduction in sucrose content and an 18.8% decrease in caloric value. While the consistency of the preparations was slightly altered, the phenolic content and antioxidant capacity remained unaffected by the enzymatic treatment. These findings highlight the promising application of in situ enzymatic treatment in developing products with prebiotic properties and reduced sugar and caloric content.