Article

Instrumental and Sensory Characterization of Heat-Induced Odorants in Aseptically Packaged Soy Milk

Department of Food Science and Human Nutrition, University of Illinois, 1302 West Pennsylvania Avenue, Urbana, Illinois 61801, USA.
Journal of Agricultural and Food Chemistry (Impact Factor: 2.91). 05/2007; 55(8):3018-26. DOI: 10.1021/jf0631225
Source: PubMed
ABSTRACT
Predominant heat-induced odorants generated in soy milk by ultrahigh-temperature (UHT) processing were evaluated by sensory and instrumental techniques. Soy milks processed by UHT (143 degrees C/14 s, 143 degrees C/59 s, 154 degrees C/29 s) were compared to a control soy milk (90 degrees C/10 min) after 0, 1, and 7 days of storage (4.4 +/- 1 degrees C). Dynamic headspace dilution analysis (DHDA) and solvent-assisted flavor evaporation (SAFE) in conjunction with GC-olfactometry (GCO)/aroma extract dilution techniques and GC-MS were used to identify and quantify major aroma-active compounds. Sensory results revealed that intensities of overall aroma and sulfur and sweet aromatic flavors were affected by the processing conditions. Odorants mainly responsible for the changes in sulfur perception were methional, methanethiol, and dimethyl sulfide. Increases in 2-acetyl-1-pyrroline, 2-acetyl-thiazole, and 2-acetyl-2-thiazoline intensities were associated with roasted aromas. A marginal increase in intensity of sweet aromatic flavor could be explained by increases in 2,3-butanedione, 3-hydroxy-2-butanone, beta-damascenone, and 2- and 3-methylbutanal. Predominant lipid-derived odorants, including (E,E)-2,4-nonadienal, (E,E)-2,4-decadienal, (E,Z)-2,4-decadienal, (E)-2-nonenal, (E)-2-octenal, 1-octen-3-one, 1-octen-3-ol, and (E,Z)-2,6-nonadienal, were affected by processing conditions. Intensities of overall aroma and sulfur notes in soy milk decreased during storage, whereas other sensory attributes did not change. Color changes, evaluated by using a Chroma-meter, indicated all UHT heating conditions used in this study generated a more yellow and saturated color in soy milk in comparison to the control soy milk.

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    • "Dairy products have a mild flavor, which is easily affected by stronger flavors of other compounds. Additionally, sterilization of soymilk produces compounds with sulfur flavor such as methional, methanethiol, and dimethyl sulfide, and compounds with roasted aroma such as 2-acetyl-1-pyrroline and 2-acetyl- thiazole (Lozano et al., 2007). Furthermore, addition of soymilk to milk decreases concentration of lactose (Fiocchi et al., 2003). "
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    • ", Benitez, & Cadwallader, 2007; Suratman, Jeon, & Schmidt, 2004; Wilkens & Lin, 1970). Therefore, hexanal and furan values could explain the panel sensation of beany, grassy and oxidized flavors for UHT-treated soymilk. Few studies have been made in relation to the impact of soymilk treatment on volatile compounds and their sensory characteristics. Lozano et al. (2007) studied soymilk treated by three UHT conditions by combining time and temperature. They considered a total of 10 attributes evaluated after treatment, resulting to astringency and beany flavor as the most perceived attributes by panelist. That result is in accordance with the present study for UHT samples at day 1 of analysis as well as"
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    • "d increased significantly due to treatment applied, either heat or UHPH. However, no changes were observed in 200 MPa, 55 °C compared to base product . The predominant compound detected was hexanoic acid. In general, its levels increased in all treatments compared to soymilk base product, with a more important increase in 300 MPa, 80 °C (p < 0.05). Lozano et al. (2007) found butanoic acid and hexanoic acid in soymilk heat treated. These compounds were related to cheese aroma and sweaty odour, respectively. According to Wilkens and Lin (1970) , hexanoic acid is formed by hexanal oxidation in presence of oxygen which in turn causes a fetid odour. In the esters group, treatments at 200 MPa caused a signi"
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