Feasibility of spray chilling encapsulation for protection and stabilization of flavor compound-zinc ion complexes
The aim of this study was to investigate the feasibility of utilizing spray chilling encapsulation technology to protect the flavor compound-zinc ion complex, 2-acetylpyridine-ZnCl2 (2-APri-ZnCl2). 2-APri-ZnCl2 was loaded at 5% (w/w) in molten Hydro-KoteC®, a commercial vegetable stearin. Spray chilling of this suspension was performed using a laboratory scale Mini Spray-dryer B-290 equipped with a spray chilling accessory, a dehumidifier and a two-fluid nozzle (nozzle cap, ∅= 2.2 mm; nozzle tip, ∅ =1.4mm; 046376). The heating temperature (94C) was set at 40% above the melting point of the lipid (60-63C). Two independent trials were performed. Microencapsules were stored in 20mL sealed amber vials and stored at ambient temperature (25°C). The percent change in 2-APri-ZnCl2 , was determined using gas chromatography-flame ionization detection (GC-FID) analysis at 0, 14, 21, 30, and 70 days. Scanning (SEM) and transmission electron microscopy (TEM) were used for micro-level observation of the physical structure of the microencapsules. SEM images of samples from the lower chamber and sample vessel compartments of the spray chiller showed that the materials had physical differences related to flowability (e.g., rough vs. smooth walls) as well as an inhomogeneity with respect to particle size. Samples from the lower chamber exhibited the preferred morphological characteristics in that they had smooth walls and were of relatively homogenous size. Stability studies showed that the microencapsulated 2APri-ZnCl2 complex with 2.5% initial loading in trials 1 and 2 maintained approximately 80 and 59% retention of 2APri, respectively, after 70 days of storage at ambient temperature. The difference in stability between the two trials is thought to be due to a variance in the operational parameters of the spray chiller. Results indicate that spray-chilling encapsulation is a viable technique for the protection of the flavor compound-zinc ion complex 2-APri-ZnCl2, and may be applicable for the protection of the much less stable complexes, 2-acetyl-1-pyrroline-ZnI2 and 2-acetyl-1-pyrroline-ZnCl2. Spray-chilling encapsulated flavor compound-zinc ion complexes may be useful as flavoring materials in industrial food applications (e.g., bakery, ice cream, and soups).
Encapsulation, Spray Chilling, Flavor compound-zinc ion complex
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign