Microencapsulation of probiotics in hydrocolloid gel matrices: a review
The use of hydrocolloid gel matrices to encapsulate probiotics is of interest due to their gentle and simplicity of gel formation as well as mild condition used. This technique enhances the viability of entrapped cells during the product shelf life at least above therapeutic minimum level as well as in the gastrointestinal tract to ensure the health benefits of consumers. This review describes the advantages of microencapsulation, hydrocolloid gel matrices such as alginate, carrageenan and whey protein, microencapsulation processes, special treatments for further improvement in encapsulation efficiency of gel matrices as well as food applications of microencapsulated probiotics.
Probiotics are living microorganisms that have been used in a manufacturing of functional food products such as yogurt and cheese because they improve the intestinal microbial balance of the host (1). The health benefits of probiotics include intestinal infection control, cholesterol level control, immune system stimulation, lactose utilization improvement in lactose maldigestors (persons who cannot digest lactose), providing anticarcinogenic activity, and reduction of inflammatory bowel disease as well as Helicobacter pylori infection (2-4). In order to achieve these benefits, probiotic bacteria should be metabolically stable and active both in the product and host, which were influenced by food composition (acid, oxygen and hydrogen peroxide (5) and digestive system of host (acid, enzyme and bile salt). To make a health claim, the therapeutic minimum level should be at least 107cfu/g or ml of the product (6), which can be achieved by using microencapsulation technology. Simultaneously, low level or poor survival of free probiotic bacteria was demonstrated by many studies (7-13). It was influenced by many factors such as pH, post acidificat ...