| Abstract
| - The ability of epicatechin (EC) to inhibit the thermal development of aroma compounds (i.e., Maillardreaction products) formed during ultrahigh-temperature (UHT) processing of bovine milk was evaluated.Volatile extracts were prepared for two UHT-processed milk samples made from (1) raw milk and (2)raw milk containing 0.1% EC by solvent-assisted flavor evaporation (SAFE) and subsequently analyzedby aroma extract dilution analysis (AEDA). Sensory evaluation was also conducted by a trained panelon the intensity of cooked flavor and bitterness in four UHT-processed milk samples (0.00, 0.01,0.10, and 0.20% EC added prior to processing), as well as a commercial pasteurized milk sample forcomparison. AEDA indicated that addition of EC to raw fluid milk prior to UHT processing reducedthe overall thermal formation of key aroma-active compounds in comparison to the traditional UHTmilk sample. The largest changes in FD values were reported for methional, furfural, 2-isopropyl-3-methoxypyrazine, 2-acetyl-1-pyrroline, and 2-acetyl-2-thiazoline (Maillard-type aroma compounds)with 32-, 8-, 8-, 4-, and 4-fold reductions in formation, respectively. Sensory evaluation also revealedthat all EC-containing UHT milk samples had statistically (P< 0.05) lower cooked flavor intensity incomparison to the control, whereas the 0.2% EC sample was statistically similar to a pasteurizedmilk sample. Furthermore, addition of EC at or below 0.1% in UHT fluid milk did not significantlyincrease the bitterness intensity. Keywords: AEDA; flavonoids; UHT milk aroma, epicatechin; GCO; aroma inhibition
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