The effects of lactose hydrolysis on the lactose-free yogurt quality

Abstract

Yogurt is a dairy product obtained by fermenting milk appreciated for the benefits presented to the digestive and general consumers health and for the reduction of symptoms caused by inadequate lactose digestion. Therefore, the lactose in yogurt is better digested than that in milk, as a result of the microorganisms ability to synthesize lactase. However, a low lactose content in yogurt is not suitable for people with lactose intolerance. Thus, the most reliable remedy seems to be complete enzymatic digestion of the lactose in yogurt. The aim of the study was to investigate the influence of different lactose hydrolysis processes, the contribution of the enzyme and the milk type on the characteristics of the obtained yogurt. For a systematic approach, the non-hydrolyzed yogurt (control sample), the yogurt that was hydrolyzed before fermentation, and the co-hydrolyzed yogurt (concomitant addition of β-galactosidase and starter culture) were performed simultaneously.