30B-23 |
Effect of caking and stickiness on the retention of spray-dried encapsulated orange peel oil |
C. I. BERISTAIN1, E. Azuara1, V. Velasquez1, and E. J. Vernon-Carter2. (1) Instituto de Ciencias Basicas, Universidad Veracruzana, Luis Castelazo S/N Col Industrial-Animas, Apdo Postal 575, Xalapa, Veracruz., 91000, Mexico, (2) Depto Ingenieria Quimica, Universidad Autonoma Metropolitana-Iztapalapa, Avenida la Purisima s/n, Mexico D.F., 09340, Mexico Justification: Flavor microcapsules containing amorphous carbohydrate as wall material can undergo changes such as crystallization, clumping, sticking and caking during handling and storage. Such physical changes may lead to the released of entrapped flavors. Objective: Investigate the effect of storage temperature and water activity on caking stickiness and glass transition temperatures and evaluate the relative degree of protection of orange peel oil entrapped in mesquite gum. Methods: Orange peel oil was encapsulated in mesquite gum by spray drying. The powders were stored in aw(s) from 0 to 0.974 at 25 and 35°C. Surface caking Tsc and sticky point temperatures Tsp were determined by the modified ampoule and sealed glass tube methods respectively. The glass transition temperature was determined by differential scanning calorimetry. Changes in the oil encapsulated was determined by Clevenger hydrodistillation and by gas chromatography analysis. Results: As expected both Tsc and Tsp decreased with increasing storage aw. Above 0.654 powders caked and collapse during storage. At water activity below 0.654 the capsules were not damage and high retention levels above 90 % were obtained. Increasing aw in the 0.765-0.974 range caused progressive dissolution of the wall polymer and the retention dropped sharply. The structure was completely destroyed at aw=0.974 leading to total loss of the volatiles. The caking temperature was 30°C to 50°C higher than the observed glass transition temperature. Significance: The volatiles are protected and retained by mesquite gum as long as the capsule structure is intact.
Session 30B, Fruit & Vegetable Products: Sensory, Product Development, Fresh-Cut, and Storage
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