45C-4 |
Aroma impact components of rabbiteye blueberry (Vaccinium ashei) vinegars |
M. S. SU and J. L. SILVA. Dept. of Food Science & Technology, Mississippi State Univ., Campus Mailstop 9805, Mississippi State, MS 39762-9805 Fruit vinegars are used widely in salad dressings. The aroma of fruit vinegars is very important. Although acetic acid is largely responsible for the vinegar note, other volatile components should have a great impact on the overall natural vinegar aroma. Thus, fruit vinegars may be characterized and differentiated by the quantitative and qualitative analysis of their volatile components. Aroma impact components of blueberry products, such as wines and vinegars, might be affected by the type of fermentation. The aroma impact components of three types of rabbiteye blueberry vinegars - vinegars made from wines without (JV) or with (WV) skin contact or directly made from blueberries (BV) were evaluated. A 20 ml sample of each treatment, with an internal standard (4-methyl-2-pentanol), was extracted with a 50:50 mixture of pentane and diethyl ether in triplicate. Headspace volatiles were isolated by solid phase microextraction (SPME). Volatile extracts and headspace volatiles were analyzed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GCO). The potent odorants were evaluated by Osme method. Three experienced panelists evaluated the aroma compounds from the GC effluents. Osme values were generated by the panelists using a 16-point scale. Compounds were identified by comparison of retention indices, odor properties and GC-MS data against reference standards. Benzaldehyde (nutty), 2-methyl-propanoic acid (rancid butter), 3-methyl-butanoic acid (sweaty), á-terpineol (pine), 2-phenylethenol (rosy), octanoic acid (sweaty), eugenol (clove), and phenylacetic acid (floral) were the most important aroma-active compounds identified in all three treatments. The contributions of these compounds to each sample were different. The numbers of identified aroma-active compounds are more in BV than in other two treatments. The type of fermentation impacts aroma components of rabbiteye blueberry vinegars. These findings will aid in choosing the method that will yield the best quality vinegar.
Session 45C, Food Chemistry: Flavor and aroma chemistry
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