title: Influence of blanching and grinding process with hot water on beany and non-beany flavor in soymilk.
abstract: A total of 8 beany odor-active compounds and 4 non-beany aroma-active compounds of traditional soymilk were identified through dynamic headspace dilution analysis (DHDA) and gas chromatography-olfactometry-mass spectrometry (GC-O-MS). To eliminate the beany flavors, soymilk was processed with hot water blanching and grinding for 2, 4, 6, 8, and 10 min with a temperature between 80 and 100 °C. A total of 5 beany odor-active compounds and 3 non-beany aroma-active compounds of this soymilk were analyzed by headspace solid phase microextraction (HS-SPME). As a result, lipoxygenase (LOX) activity gradually decreased by hot water treatment with time, and with the decrease of Lox activity, the 5 beany odor-active compounds and 3 non-beany aroma-active compounds were significantly decreased. However, the reduction in non-beany flavor compounds was smaller than for beany odor compounds. Therefore, a balance between beany and non-beany flavors can be reached in soymilk. When the soaked soybeans were blanched and ground with hot water for 2 to 6 min, the LOX activity was between 38% and 57% of the beginning activity. For these processing times, the non-beany compounds could be largely maintained. The ratio of the total peak area of the 3 non-beany aroma compounds and 5 beany flavor compounds was between 0.07 and 0.12, and the sensory scores of the aromas were higher than that of the off-flavors. Practical Application: Beany flavors in soymilk could be reduced with hot water blanching and grinding at temperature above 80 °C. However, the treatment of hot water blanching affected the non-beany aromas of soymilk. A suitable blanching and grinding time is necessary to achieve a balance of soymilk flavors.
authors.affiliation: College of Food Science & Nutritional Engineering, China Agricultural Univ., Beijing 100083, China.
authors.forename: Yan-Chun
authors.initials: YC
authors.lastname: Lv
authors.forename: Huan-Lu
authors.initials: HL
authors.lastname: Song
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: Wu
authors.forename: Shun-Tang
authors.initials: ST
authors.lastname: Guo
mesh_terms: D019342:Acetic Acid / Q000032:analysis; D000447:Aldehydes / Q000032:analysis; D005233:Fatty Alcohols / Q000032:analysis; D005260:Female; D005410:Flame Ionization; D005511:Food Handling / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008084:Lipoxygenase / Q000378:metabolism; D008297:Male; D009812:Odorants; D012639:Seeds / Q000737:chemistry / Q000201:enzymology; D012677:Sensation; D052617:Solid Phase Microextraction; D041942:Soy Milk / Q000737:chemistry* / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry / Q000201:enzymology; D013649:Taste; D013997:Time Factors; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000447:Aldehydes; D005233:Fatty Alcohols; D055549:Volatile Organic Compounds; D008084:Lipoxygenase; D019342:Acetic Acid