JAMES D. OXLEY

Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, USA

Abstract

Flavours and bioactives often require increased stabilization for incorporation into a finished product. Enhanced stability and shelf-life may be obtained through the use of microencapsulation, entrapping the ingredients within a protective shell or matrix to provide protection from the surrounding environment or providing a unique controlled release profile. Once developed, it is important to have an established set of techniques and assays available to quantify the performance of the capsules for stability and shelf-life prediction. Due to the wide variety of microcapsule formulations and applications, customized evaluation is required for each encapsulation system. There are several general elements to consider when designing a system for analyzing stability and predicting shelf-life.

INTRODUCTION

Microencapsulation is a common tool for the protection and delivery of flavours and bioactives. There are a variety of methods, formulations and reasons to encapsulate an ingredient. Common methods include spray drying, fluid bed coating, coextrusion, or emulsion based techniques. Formulations can include encapsulating with proteins, starches, polysaccharides, polymers, and other hydrocolloids. A few common reasons to encapsulate flavours or bioactives include protection from the environment, stabilization during storage, or controlled release in the final application. Regardless of the chosen technique, formulation or reason for encapsulation, the final product must be tested for stability and shelf-life. The variety of methods and techniques used for stability and shelf-life prediction are almost as numerous as the encapsulation technique and formulation combinations. In all cases, characterization is first required, followed by a stability assessment and analysis of the data to generate suitable shelf-life prediction.

CHARACTERIZATION
Proper characterization of an encapsulation system is the foundation of ...