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A. PLOTTO1, K. L. Goodner1, C. A. Margaria2, and E. A. Baldwin1. (1) Quality Improvement Research Unit, USDA-ARS-Citrus & Subtropical Products Laboratory, 600 Ave. S. N.W., Winter Haven, FL 33881, (2) United States Distilled Products Co., 1607 12th St. S., Princeton, MN 55371 Thresholds for flavor volatiles have been traditionally calculated in water or air, but they may vary widely in more complex matrices such as milk, gels, or fruit slurries. The data presented is a summary of a study that provides the industry with threshold guidelines more adequate for the use of flavors in citrus juices. Thresholds of volatile compounds known to be important for orange juice (OJ) flavor were determined in a deodorized OJ matrix. The Three-Alternative-Forced-Choice (3-AFC) method was used (ASTM: E-679) with a dilution factor of 3 between each step. Sixteen to twenty experienced panelists participated in the study. For each compound, the test was repeated four times, or until the threshold was determined with certainty. For most terpenes and long-chain aldehydes, odor thresholds in the juice were up to 200 times higher than in water (alpha- and beta-pinene, limonene, octanal), while for more soluble aldehydes and the terpene-alcohol linalool, the threshold in juice was about 10 to 15 times higher than published values in water. In contrast, odor and taste thresholds for esters were only twice (methyl butanoate) to ten times higher in the orange juice matrix than published values in water, except for ethyl propanoate, which was 30 times higher. Odor thresholds were generally higher than retronasal thresholds. At subthreshold concentrations, compounds tended to decrease perception of sweet taste. At supra-threshold, most esters increased fruitiness, but some imparted a spoiled flavor. While thresholds followed a unimodal normal distribution for most compounds, a bimodal distribution was found between panelists for sensitivity to beta-ionone and beta-damascenone. These results show the importance of nonsoluble compounds on odor and flavor perception. The effect of volatile-matrix interactions will be discussed. The threshold values provided by this research are directly applicable by the industry in comparison with the current values that are published in water.
Session 41, Citrus and flavors
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |