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.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.
"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). "
[Show abstract][Hide abstract]ABSTRACT: The aim of the present study was to investigate the effect of addition of soymilk on physicochemical, microbial, and sensory characteristics of milk fermented with Lactobacillus acidophilus. Soybeans were blended 1:5 w/v with distilled water. The prepared soymilk was added to milk in combinations of 20%, 40%, and 60%. Milk was used as the control. All the samples were sterilized and fermented with Lactobacillus acidophilus LA-5 as probiotics. Then, they were kept at 5ºC for 14 days. Microbial count, titratable acidity, pH, syneresis, color parameters and sensory evaluation were performed during the storage time. Results showed that all the samples possessed minimum effective dose of LA-5 on day 14, although a significant decrease in LA-5 was observed in the sample with 60% soymilk. In each experimental day, there was a noticeable decrease in the pH of the samples. Addition of soymilk to milk also significantly increased syneresis, particularly in samples with 60% soymilk. Sensory evaluations showed that scores of texture, mouth sense, aroma, and flavor of the samples with 40% and 60% soymilk were significantly lower than other samples. With respect to color, “L” value decreased significantly in the fermented product with 60% soymilk and the decrease was more pronounced with longer storage times. In conclusion, addition of 20% soymilk did not substantially alter physicochemical and sensory characteristics of milk while providing an appropriate growth culture for LA-5. The mixture of milk-20% soymilk can be introduced as a good probiotic product with lower lactose content and additional nutritional benefits.
Full-text · Article · Nov 2014 · Iranian Journal of Veterinary Research
", 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"
[Show abstract][Hide abstract]ABSTRACT: Ultra high pressure homogenization (UHPH) was applied on soymilk to produce an aseptically packaged beverage. UHPH-treated soymilk (300 MPa, 80 °C inlet temperature and 144 °C/0.7 s at the homogenization valve) was compared with samples treated by ultra high temperature (UHT) at 142 °C for 6 s. After treatment, soymilk samples were aseptically packaged in coated paperboard cartons of 200 mL Tetra Brik containers. Tetra Brik containers were stored for 6 months at room temperature and analyzed at different days. Microbiological (total mesophilic aerobic bacteria, aerobic spores, Bacillus cereus, and enterobacteria counts), physical (dispersion stability and particle size distribution), chemical (hydroperoxide index and volatile profile evolution) and sensory analyses were performed on soymilks. Both UHPH and UHT soymilks did not present microbiological growth during storage. UHPH soymilk presented high colloidal stability and relevant decrease in hydroperoxide index during storage. On the other hand, almost all of the compounds associated to off-flavors were detected in the volatile profile of soymilk. Sensory results indicated that UHPH treatment did not produce changes in soymilk which could affect the panel perception for different UHT and UHPH soymilks and for selecting their preference.
"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"
[Show abstract][Hide abstract]ABSTRACT: The effect of ultra high pressure homogenisation (UHPH) on the volatile profile of soymilk was studied and compared with conventional treatments. Soymilk was treated at 200MPa combined with two inlet temperatures (55 or 75°C) and treated at 300MPa at 80°C inlet temperature. UHPH-treated soymilks were compared with base product (untreated sample), pasteurised soymilk (90°C, 30s) and ultra high temperature (UHT; 142°C, 6s) treated samples. Volatile compounds were extracted by solid-phase microextraction and were identified by gas chromatography coupled with mass spectrometry. Pasteurisation and UHPH treatments at 200MPa produced few changes in the volatile composition, reaching similar values to untreated soymilk. UHT treatment produced the most important effects on volatile profile compared to UHPH at 300MPa and 80°C. Hexanal was the most abundant compound detected in all treatments. The effect of UHPH technology on volatile profile induced modifications depending on the combinations of processing parameters.