Soybean meal nano scales resistant starch- model carbohydrates for encapsulation of bioactive compounds

摘要

Nano particles, because of their release efficiency and reduced toxicity, are widely used as encapsulating materials. Resistant starch serves as a particularly good source of encapsulating materials; it is resistant to enzymatic digestion by pancreatic enzymes in mono gastric animals like human. This RS can be used to encapsulate substances that are unstable to light, heat, oxygen and upper intestinal physiological environment. This study researched the use and benefits of RS as an encapsulating material. The resistant starch (RS) fraction of soybean meal was isolated using enzyme assays with a-amylase and amyloglucosidase. The isolated RS was sonicated at 40 °C for 5 hours. The resulting particles sizes ranged from 60 to 80 nm. This material was then coated on a glass bead; this served to construct a model system for targeted delivery to colon. The chemical digestion mimicked the small intestine with pH 4.5 and 8.5 and the stomach with pH 1.5 and 6.5. The percentage of dissolution in both the stomach and the intestine showed 15-30%. The enzymatic digestion with pancreatic α -amylase and amyloglucosidase showed less than 30% digestion. The thermal stability of the encapsulated system was studied with differential scanning calorimetry (DSC). The DSC showed the stability of the material of up to 101 °C and an enthalpy of 277.3 J/g. This study demonstrated that soybean meal RS can be used to encapsulate minerals, micronutrients, antioxidants, and drugs. Encapsulation using RS as the nano based materials could provide means to increase chemical and physical stabilities of the encapsulated material.