Vitamin C stability in encapsulated green West Indian cherry juice and in encapsulated synthetic ascorbic acid

Kinetic studies on the degradation of vitamin C and nonenzymatic browning of green West Indian cherry juice and synthetic ascorbic acid, encapsulated in maltodextrin DE20 and a mixture of this with gum arabic, were carried out at different temperatures (15, 25, 35 and 45 degrees C). Vitamin C degradation followed the first-order and nonenzymatic browning a zero-order kinetic model. At higher storage temperatures the formulation containing a mixture of maltodextrin and gum arabic (3:1) was the most effective for vitamin C protection. An increase in storage temperature showed a greater impact on the degradation of synthetic vitamin C than on that of the green West Indian cherry juice. These differences could be due to the presence of phenolic compounds with antioxidant activity, protecting the vitamin C. (c) 2006 Society of Chemical Industry8681202120

Effect of encapsulating materials on water sorption, glass transition and stability of juice from immature acerola

Immature acerola juice was dehydrated by spray drying, using as encapsulating material maltodextrin DE25, arabic gum, or a mixture of both in different proportions. A constant ratio of 1:1 was kept between juice solids and encapsulating material. The effect of encapsulation materials on water sorption, glass transition, and physical properties of encapsulated immature acerola juice was investigated. The monolayer moisture of the encapsulated juices, calculated according to the GAB theory, varied from 5.11 to 5.73g H2O/100g of solids (25 degrees C). The glass transition temperature (T-g) of maltodextrin and gum arabic varied from 60 (a(w) 0.33) to 38 degrees C (a(w) 0.54), and from 62 (a(w) 0.33) to 42.6 degrees C (a(w) 0.54), respectively. The addition of juice to the encapsulating materials decreased the T-g of the juice powder to 39.5-41.3 degrees C (a(w) 0.33) and 1.84-8.05 degrees C (a(w) 0.54), but no marked differences were found among the juice powders. The critical a(w) i.e., the point of onset of physical alterations in the encapsulated materials, was higher than the corresponding monolayer values. Stickiness was observed at temperatures close to T-g, and collapse occurred at temperatures of 20 degrees C or more above the T-g. Maltodextrin DE25 and gum arabic offered equivalent contributions to the stability of the system.8233734