Structure and properties of citrus pectin as influencing factors of biomarkers of metabolic syndrome in rats fed with a high-fat diet

Abstract

Pectin, widely used as a food and pharmaceutical ingredient, has garnered attention in recent years due to its bioactive properties. We conducted an in vivo study to evaluate the effects of citrus pectin on biomarkers of metabolic syndrome (MtS), including lipid profile, hypertension, and adipose tissue. Supplementing a high-fat diet (60% energy from fat) with 20% pectin for 4 weeks significantly reduced body weight and fat accumulation, improved insulin resistance, and decreased circulating leptin levels, demonstrating a beneficial effect on MtS. Pectin exhibited excellent viscosity, emulsifying properties, and water-holding capacity, forming a viscous gel in the gastrointestinal tract. This gel delays gastric emptying, enhances satiety, and reduces food and calorie intake, leading to lower weight gain in rats fed pectin. Its viscosity also interferes with lipase activity, lipid hydrolysis, and absorption, while its oil-holding capacity may help prevent lipid absorption. The presence of galactose in pectin's structure showed potential for improving insulin resistance. Furthermore, both degree of esterification (DE) and pH influence pectin's functionality. At acidic pH levels, such as those found in the stomach and duodenum, high methoxyl pectin (HMP) retains fats and bile salts more effectively, contributing to better cholesterol regulation. These effects, combined with the antioxidant properties of pectin, helped reverse arterial hypertension associated with MtS. Overall, our findings highlight the potential of citrus pectin as a natural bioactive ingredient for combating obesity-related disorders, complementing pharmacological treatments and promoting health through innovative dietary approaches.