Effect of ultrasound assisted extraction upon the Genistin and Daidzin contents of resultant soymilk

Abstract

The purpose of this study was to determine the effect of ultrasound treatment on the contents of daidzin, genistin, and their respective aglycones, daidzein and genistein, in resultant soymilk. Soybean slurry was exposed to ultrasound treatment, filtered, and placed in an ultrasound cleaning bath set with different frequencies (35and 130 KHz), treatment temperatures (20 and 40°C), and times (20, 40, and 60 min). Concentrations for these isoflavones were determined using reverse-phase high-performance liquid chromatography. Results indicated that both frequencies significantly (p<0.05) increased isoflavone content (IC), glycosides, and aglycones in extracted soymilk. These results were attributed to induced cavitation, which increases the permeability of plant tissues. However, the frequency of 35 kHz caused a noticeably higher increase in IC than 130 kHz. Results also revealed significant increases in IC with increased sonication time (from 20 to 60 min) and with increased temperature (from 20 to 40°C).

Changes in Bioactive Compounds Concentration and Physicochemical Properties of Mango Smoothies Treated by Ultrasound

“…Hence, it might be possible that US treatment induced some physical or biochemical reactions within the SM-MS, leading to the changes observed in its isoflavone profile. Just like the achieved results, a significant interconversion of isoflavone glucosides to aglycones during processing was reported by Fahmi et al (2012). These authors elucidated that the ratio of aglycones to glucosides increased by 19 -23 % in soymilk obtained from a sonicated slurry.…”

“…This phenomenon was also observed by Fahmi et al (2012) in a US treated-soymilk slurry at different frequencies (35 and 130 kHz), treatment temperatures (20 -40°C) and times (20, 40 and 60 min). These authors indicated that, by increasing treatment time (from 20 to 60 min) and temperature (from 20 to 40°C ), isoflavone content of soymilk obtained from the sonicated slurry significantly increased; however, the changes were more noticeable at 35 kHz.…”

“…Unfortunately, similar studies evaluating the isoflavone profile of fruit-smoothies with soymilk as affected by US processing have not been reported up today. Nonetheless, other works conducted in soymilk and a fruit juice-soymilk beverage treated with thermal pasteurization, high hydrostatic pressures or pulsed electric fields describe interesting information (Fahmi et al, 2012;Morales-de la Peña et al, 2010;Jung et al, 2008;Giri and Mangaraj, 2012;Murphy et al 1999;Yen and Kao 2002). For instance, Yen and Kao (2002) evaluated the changes on the isoflavone profile of soymilk obtained from black soybean soaked at different temperatures (30 and 50°C) and times (6, 8 and 12 h).…”

“…In this respect, ultrasound (US) technology has received special attention because it can be cheap, simple, environmental-friendly, and effective treatment in extending shelf-life of beverages, particularly when it is combined with mild heat (thermosonication) (Abdullah, 2014). Some authors have demonstrated that US processing caused minimal impact on quality parameters and great retention of health related compounds in orange, guava, and strawberry juices, purple cactus pear, and soymilk (Abdullah, 2014;Cheng et al, 2014;Fahmi et al, 2012;Sakhale et al, 2012;Ribeiro et al, 2014;Chauhan and Patil, 2013). However, information about the effects of US treatment together with the application of mild heat on physicochemical properties and health-related compounds of mango smoothies is not available.…”

Analysis of Isoflavones in Foods

“…Solid samples need to be ground, whereas liquid samples do not. However, in some cases liquid samples are freeze‐dried and treated the same as solid samples (Otieno and others ; Jung and others ; Toro‐Funes and others , , ; Fahmi and others ).…”