Storage of Citrus Oils

The primary benefit claimed in this patent was the maintainence of fresh flavor in encapsulated citrus oils which otherwise would readily oxidize during storage, yielding objectionable off-flavors. While spray dried flavorings have continued to dominate the dry flavor market, encapsulated products have been gaining market share. Initial studies that led to the work of Swisher (1 ) were done by Schultz et al (2), This work involved the addition of citrus oils to a molten solution of sucrose and dextrose, cooling the solution to form a hard slab similar to rock candy and then grinding the solid to the desired size. 

The desired citrus flavor is the result of volatile compounds in specific proportions. Citrus oils have unique composition profiles depending on the cultivar, the processing conditions, and the storage conditions. There have been more than 200 different compounds identified in citrus oils. However, the degree of unsaturation in monoterpenes leads to rapid oxidation and unstable compounds. The reactivity and volatility of citrus oils require strict quality control protocols. 

Citrus peel oils have been used widely in beverages, cosmetics, pharmaceuticals, and perfumery industry, whereas seed oils are used in cooking and for treatment of leather and textile. The quality, freshness, and uniqueness of citrus oils are major considerations pertaining to their value and applications (43). However, large amounts of volatile components, as well as unsaturated compounds, render the oils unstable and prone to change with time and storage conditions. 

Processing effects. Citrus oil quality may be affected by certain processing parameters. Some which have been studied include effects of yield from the fruit, the amount of water used during recovery and extraction, storage of fruit prior to processing, blending of fruit varieties, and handling the emulsion or finished oils (12). 

D Amore and Corigliano (155) indicated the intense fluorescence of Mediterrean mandarin oil at 415 nm might be useful for characterization and detection of adulteration. Slater (156) reported the ratio of some infrared peak intensities might be useful for detection of adulteration or storage abuse in citrus oils. 

Table 7 shows the fatty acid composition of different citrus seed oils. The ratio of unsaturated to saturated fatty acids is approximately 2 1 (9), although this ratio was reported to be in the range of 3-5 1 by Nagy (35). Generally, different varieties, cultivar, location, storage condition, and harvesting time of citrus fruit may lead to this variation. Table 8 shows the content of the six major fatty acids in different citrus seed oils these are linoleic (C18 2), palmitic (C16 0), oleic (C18 l), linolenic (C18 3), stearic (C18 0), and palmitoleic (C16 l) acids. 

Citrus peel oils are generally collected from fruit as it processed into juice. These citrus oils are used as flavorings in numerous products from Juices to cosmetics. There are many factors that affect the aroma of the peel oil, such as type of fruit, harvest maturity, processing affects, storage, and others (/, 2, 3, 4),... 

The most common problem occurring during flavor storage is deterioration due to oxidation. Any flavoring containing citrus oils or oils based on aldehydes is susceptible to oxidative reactions and development of off-flavors. Thus, an important function of an edible film is protection of the flavoring from oxygen. 

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