Using biopolymer blends for shrimp feedstuff microencapsulation - I. Microcapsule particle size, morphology and microstructure

dA shrimp feedstuff was microencapsulated through spray drying using differ ent biopolymer treatments as wall materials after a three component Simplex Centroid experimental design, employing wall material to feedstuff ratios of 2:1 and 3:1, and pH values of 4 and 8. The response surface methodology indicated that the three above mentioned variables affected the microcapsul e particle size and microstructure, as evidenced by scanning electron micro scopy. Predictive equations show that the factor that affected significantl y the microcapsule particle size was the binary interactions among the biop olymers. The higher the wall material-feedstuff ratio the larger the microc apsule particle size. As pH varied from 4 to 8, the biopolymer adsorbed lay ers around the core material were more extended. All the resulting microcap sules were of the matrix type, in which the feedstuff microparticles were d istributed within the solid wall material matrix. (C) 1999 Canadian Institu te of Food Science and Technology. Published by Elsevier Science Ltd. All r ights reserved.