Encapsulation By Extrusion

Encapsulation of flavors by extrusion incorporated the basic techniques of solvent dehydration with a novel method for providing excellent protection to the core materials. The process involves the preparation of a low-moisture (5— 10%) melt (100°-130°C) of low DE malto dextrin, sugar, and modified edible starch. The flavor to be encapsulated is combined along with an emulsifier and optionally an antioxidant, and mixed with a melt under extreme agitation. The molten emulsion is extruded through holes about 1/64 in. into a cold, isopropanol bath. The melt solidifies and is broken into small rods by agitation. The flavor particles are recovered by filtration, or centrifugation, often mixed with a flow agent and packaged for sale. The literature discusses many variations in the process. Some are designed to increase the payload (typically 8-10% flavor); often flavor capsules are given additional solvent washes to remove traces of surface oils further improving the exceptional stability this process affords to deterioration by oxidation. As such it is particularly useful with citrus-flavored oils (9).

Development of today's encapsulation by extrusion solvent dehydration began more than 30 years ago. It really comes from a process developed in 1956 involving adding flavor oils to a molten solution of sucrose and dextrose, cooling the solution to a hard slab, and subsequently grinding the rock-candy-like product to the desired particle size (10,11). From the development of pulverized rock-candy flavor to the current state-of-the-art flavor encapsulation by extrusion, significant processing and product improvements have been made by a number of inventors covered by at least six important patents. At one point there were three companies in the United States selling what was advertised as extruded flavor capsules. The volume, however, although significant never reached the size that the quality of these encapsulates would seem to merit. High process cost (perhaps as much as six times the cost of spray drying) is the major factor. Improvements in spray-drying technology, particularly improvements in formulating flavors designed for spray dehydration have narrowed the quality gap. When a dry flavor is required spray drying is still the technology of choice unless the need for the superior quality of extruded capsules is great enough to warrant the added costs.

Homemade Pet Food Secrets

Homemade Pet Food Secrets

It is a well known fact that homemade food is always a healthier option for pets when compared to the market packed food. The increasing hazards to the health of the pets have made pet owners stick to containment of commercial pet food. The basic fundamentals of health for human beings are applicable for pets also.

Get My Free Ebook


Post a comment