Wood hemicelluloses as sustainable wall materials to protect bioactive compounds during spray drying of bilberries

The most widely-used wall materials for spray-dried microencapsulation have limitations in cost-effectiveness, health benefits and sustainability. Wood hemicelluloses, by-products of the forestry industry, including gal-actoglucomannans and glucuronoxylans have the potential to be utilized as innovative wall materials. This study investigated the applicability of galactoglucomannan and glucuronoxylan and their mixtures with carboxy-methylcellulose as wall materials for microencapsulation of bilberry juice, in comparison to gum arabic. The results indicated that galactoglucomannan and glucuronoxylan have a relatively high anthocyanin encapsulation efficiency (71-73%), which was similar to that of gum arabic (76%). The addition of carboxymethylcellulose reduced the encapsulation efficiency of wood hemicelluloses to 46-54%. Microencapsulated powders prepared with wood hemicelluloses were considerably higher in total phenolic content and antioxidant activities than those prepared with gum arabic, and mixtures of wood hemicelluloses with carboxymethylcellulose. The results indicate that wood hemicelluloses are efficient wall materials for spray-dried microencapsulation of bioactive compounds.