Mingruo Guo
The University of Vermont, USA
Title: Whey protein based microencapsulation of bioactive compounds and probiotics
Biography
Biography: Mingruo Guo
Abstract
Ginsenosides is a group of the bioactive compounds in ginseng. Its application in functional dairy foods is limited due to the bitter taste and yellowish color of ginsenosides. Using polymerized whey protein as the wall material to capsulate ginsenosides may effectively mask its bitter taste and improve the color. Probiotics are widely used in functional fermented foods. Polymerized whey protein based microencapsulation of probiotics might improve their survivability during digestion. The results showed that entrapment yield of the microencapsulated ginsenosides and Lactobacillus Acidophilus (L. Acidophilus) was 95.46±1.95% and 92.90±3.97%, respectively. The probiotic yogurt chemical composition, texture, syneresis, viscosity and sensory properties were analyzed and compared between the experimental sample and the control. There was no significant difference in moisture and ash content between the experimental and the control sample (p>0.05). The yoghurt with microencapsulated ginsenosides displayed the higher viscosity, gumminess, hardness and adhesiveness. The syneresis of experimental sample was significantly lower than that of the control (p<0.01). Sensory evaluation (score scale 1-5) showed that the acceptability score of the experimental yoghurt (3.7) was much higher than the control (1.6). The population the probiotic was above 106 CFU/ml in the yoghurt for the first six-week storage. Results showed that the microcapsules of L. Acidophilus were intact after treated by gastric juice but L. Acidophilus were released in the small intestine juice while the free cells had died out. The results indicated that the polymerized whey protein based microencapsulation might be an effective technique to mask bitter taste and improve the color of probiotic yoghurt containing ginsenosides. They could be released from the capsules in small intestine. And the polymerized whey protein based microencapsulation might protect L. Acidophilus from the acidic gastric juice.