Effects of pectins and sugars on β-carotene bioaccessibility in an in vitro simulated digestion model

There is lack of information about the effects of pectin and sugars on carotenoid delivery in a simple juice model system. Therefore, the effect of pectin and sugars on beta-carotene bioaccessibility (CBA) and the characteristics of digestive fluids in juice model systems were studied. Carotenoid retention ratio (CRR) in the small intestine and the characteristics of digestive fluids, including color parameters and rheological properties, were investigated to gain insight into the mechanism that can alter carotenoid bioaccessibility. Results illustrated that higher pectin concentration, medium methoxyl pectin (MMP), and low methoxyl pectin (LMP) increased the initial apparent viscosity. However, there was no marked difference for the apparent viscosity of all systems in the stomach and small intestine phases. Generally, systems with sugars had higher CRR than those with pectin. Lower pectin concentration increased CBA. Systems with MMP had higher CBA than those containing high methoxyl pectin (HMP) and LMP; therefore, the effects of degree of methoxylation (DM) were not proportional to CBA. Among systems with different sugars, sucrose could achieve the highest CBA (4.59%). A comprehensive investigation of the effects of pectin and sugars on carotenoid delivery during digestion will be a theoretical guidance to improve nutritional qualities of juice products.