MICROENCAPSULATION OF CALCIUM LACTOBIONATE FOR PROTECTION FROM MICROORGANISMS IN A SOLID PHASE FOOD

Abstract

Prebiotic compounds may be consumed during storage by the foodstuff’s own microflora, so that new processes to protect these bioactive compounds before they are released in the gastrointestinal tract need to be developed. With this aim, lyophilized calcium lactobionate microparticles were designed, employing different coat materials (caseinate, gelatine, gum arabic, maltodextrin and mixtures of gum arabic and maltodextrin), some of which had previously been treated with transglutaminase enzyme. The microparticles were introduced into cottage cheese, as an example of a matrix with low water activity, and were found to exert a successful protective effect against consumption of lactobionate by lactic acid bacteria present in the cheese. Diffusion of the calcium lactobionate to the surface of the microparticles and diffusion of the lactic bacteria into the microparticles were negligible during the tested period. A model was developed to simulate the lactobionate consumption in the microparticles-cheese system. All the microparticles tested had good protective characteristics and no important improvement was observed when transglutaminase was added. Microparticles of sodium caseinate were chosen for the final digestibility analyses. Subsequently, in the digestibility tests, the calcium lactobionate was released from sodium caseinate microparticles in the cottage cheese under both gastric and intestinal conditions. Therefore, this study presents a protective microparticle process for use in functional food products.