Shelf-life determination, encapsulated

Once we had determined the optimum practical a for the storage of encapsulated orange peel oil, we initiated a study on the influence of spray dryer inlet and exit air temperature on product shelf-life. 

Storage Stability. The formation of limonene oxide at 37 C was measured as a function of time to determine shelf-life of the encapsulated orange peel oil samples. Figure 6 shows the shelf-life results. A value of 2mg limonene oxide/g limonene was used as the end of shelf-life for oxidized encapsulated oil samples ( 3) The sample dried at 160 C and 105 C inlet and exit air temperatures respectively and the smallest temperature differential (55 C). This sample formed limonene oxide much faster than the other five samples. By 23 days, this powder had reached a value of 2mg limonene oxide/g limonene. The sample dried at 280 C and 105 C inlet and exit temperatures respectively did not reach 2 mg limonene oxide/g limonene until after 34 days of storage at 37 C. This sample also had the largest inlet and exit air temperature differential (175 C). The remaining four samples had reached 2mg limonene oxide/g limonene after about 30 days of storage at 37 C. 

Little work has been published comparing the shelf life of flavors encapsulated by different processes. The purpose of this investigation was to determine the shelf life of cold pressed orange oil encapsulated by spray drying, extrusion, and molecular inclusion. Limonene-1,2-epoxide concentration was used to monitor oxidation. 

For determination of shelf-life of cookies, control cookies and sample cookies were prepared in accordance to the method, discussed in Sect. 3.1 with little modification and stored for a period of200 days. The amount of encapsulated clove extract in the sample cookie formulation was 2.5 % of the dough weight. The e-nose system was trained with deliberately made-rancid cookies , prepared by storing control cookies in a rancidity chamber for 1, 3, 10, 20 and 30 days. 

Water Activity The role of water activity in determining shelf life of the spray-dried powders is of interest. It is well documented in the literature that lipid oxidation is slowest at the monolayer (water activity ca. 0.2) and will increase on either side of the monolayer. Anker and Reineccius [86] found that shelf life of orange peel oil encapsulated in gum Arabic increased with water activity within the range of water... 

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