J Food Bioact

Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online

Journal website www.isnff-jfb.com

Original Research

Volume 6, June 2019, pages 140-147

Ultrasound- and hemicellulase-assisted extraction increase β-glucosidase activity, the content of isoflavone aglycones and antioxidant potential of soymilk

Figure 1. Effect of hemicellulaseassisted extraction (HAE) and ultrasound-assisted extraction (UAE) on the activity of endogenous ß-glucosidase. Means with different letters show difference among treatments (p < 0.05).

Figure 2. The contribuition of different forms of isoflavones in soymilk as affected by hemicellulase-assisted extraction (HAE) and ultrasound-assisted extraction (UAE).

Figure 3. Concentration changes of different forms of isoflavones in soymilk as affected by hemicellulase-assisted extraction (a) and ultrasound-assisted extraction (b). #1, 2, 3, and 4 (blank bars) are total conjugated isoflavones, conjugated daidzein, conjugated glycitein, and conjugated genistein, respectively. The same numbers (black bars) are total aglycone isoflavones, daidzein, glycitein, and genistein, respectively.

Figure 4. Antiradical activity of soymilk produced under hemicellulase-assisted extraction (HAE) and ultrasound-assisted extraction (UAE). Data represent the mean ± standard deviation of each sample (n = 3). Means with different letters indicate significant differences (p < 0.05) among treatments, considering each assay.

**Table 1.** Isoflavone profile (µmol g⁻¹ dw) of soymilk obtained by conventional method (control), hemicellulase-assisted extraction (HAE), and ultrasound-assisted extraction (UAE)
	control	HAE	UAE
Data represent mean values ± standard deviation (n = 3). Values followed by the same letters within a column are not significantly different (p > 0.05). DW is dry weight. The contents (µmol g⁻¹ dw) of isoflavones in the original soybean were 1.84 ± 0.27 (malonylglucosides); 0.62 ± 0.03 (malonyldaidzin); 0.34 ± 0.01 (malonylglycitin); 0.88 ± 0.02 (malonylgenistin); 0.71 ± 0.02 (β-glucosides); 0.26 ± 0.01 (daidzin); 0.22 ± 0.01 (glycitin); 0.23 ± 0.01 (genistin); 0.17 ± 0.00 (aglycones); 0.06 ± 0.00 (daidzein); 0.06 ± 0.00 (glyctein); 0.06 ± 0.00 (genistein)..
Malonylglucosides	1.72 ± 0.01^a	1.41 ± 0.02^c	1.55 ± 0.01^b
malonyldaidzin	0.57 ± 0.00^a	0.45 ± 0.01^c	0.51 ± 0.01^b
malonylglycitin	0.25 ± 0.00^a	0.21 ± 0.00^c	0.23 ± 0.00^b
malonylgenistin	0.91 ± 0.00^a	0.76 ± 0.01^c	0.82 ± 0.00^b
β-Glucosides	0.47 ± 0.01^a	0.28 ± 0.01^b	0.28 ± 0.00^b
daidzin	0.19 ± 0.00^a	0.12 ± 0.01^b	0.12 ± 0.00^b
glycitin	0.12 ± 0.00^a	0.07 ± 0.00^b	0.07 ± 0.00^b
genistin	0.16 ± 0.00^a	0.09 ± 0.00^b	0.09 ± 0.00^b
Aglycones	0.26 ± 0.01^c	0.44 ± 0.00^b	0.63 ± 0.04^a
daidzein	0.10 ± 0.01^c	0.15 ± 0.00^b	0.21 ± 0.00^a
glycitein	0.05 ± 0.00^c	0.11 ± 0.00^b	0.14 ± 0.00^a
genistein	0.11 ± 0.02^b	0.17 ± 0.00^b	0.28 ± 0.04^a

Table 1. Isoflavone profile (µmol g⁻¹ dw) of soymilk obtained by conventional method (control), hemicellulase-assisted extraction (HAE), and ultrasound-assisted extraction (UAE)

control

HAE

UAE

Data represent mean values ± standard deviation (n = 3). Values followed by the same letters within a column are not significantly different (p > 0.05). DW is dry weight. The contents (µmol g⁻¹ dw) of isoflavones in the original soybean were 1.84 ± 0.27 (malonylglucosides); 0.62 ± 0.03 (malonyldaidzin); 0.34 ± 0.01 (malonylglycitin); 0.88 ± 0.02 (malonylgenistin); 0.71 ± 0.02 (β-glucosides); 0.26 ± 0.01 (daidzin); 0.22 ± 0.01 (glycitin); 0.23 ± 0.01 (genistin); 0.17 ± 0.00 (aglycones); 0.06 ± 0.00 (daidzein); 0.06 ± 0.00 (glyctein); 0.06 ± 0.00 (genistein)..

Malonylglucosides

1.72 ± 0.01^a

1.41 ± 0.02^c

1.55 ± 0.01^b

malonyldaidzin

0.57 ± 0.00^a

0.45 ± 0.01^c

0.51 ± 0.01^b

malonylglycitin

0.25 ± 0.00^a

0.21 ± 0.00^c

0.23 ± 0.00^b

malonylgenistin

0.91 ± 0.00^a

0.76 ± 0.01^c

0.82 ± 0.00^b

β-Glucosides

0.47 ± 0.01^a

0.28 ± 0.01^b

0.28 ± 0.00^b

daidzin

0.19 ± 0.00^a

0.12 ± 0.01^b

0.12 ± 0.00^b

glycitin

0.12 ± 0.00^a

0.07 ± 0.00^b

genistin

0.16 ± 0.00^a

0.09 ± 0.00^b

Aglycones

0.26 ± 0.01^c

0.44 ± 0.00^b

0.63 ± 0.04^a

daidzein

0.10 ± 0.01^c

0.15 ± 0.00^b

0.21 ± 0.00^a

glycitein

0.05 ± 0.00^c

0.11 ± 0.00^b

0.14 ± 0.00^a

genistein

0.11 ± 0.02^b

0.17 ± 0.00^b

0.28 ± 0.04^a

**Table 2.** Aglycone to conjugated isoflavone ratio as an index of antioxidant potential
	Ratio
Abbreviations: aISO, aglycone isoflavones; cISO, conjugated isoflavones; aDAI, daidzein; cDAI, conjugated daidzein; aGly, glycitein; cGly, conjugated glycitein; aGEN, genistein; cGEN, conjugated genistein; Data represent mean values ± standard deviation (n = 3). Values followed by the same letters within a column are not significantly different (p > 0.05). *significant at p < 0.05.
feedstock	0.068 ± 0.003^d	0.063 ± 0.002^d	0.105 ± 0.005^d	0.053 ± 0.001^d
control	0.120 ± 0.006^c	0.132 ± 0.009^c	0.146 ± 0.005^c	0.102 ± 0.015^c
HAE	0.258 ± 0.002^b	0.268 ± 0.003^b	0.404 ± 0.005^b	0.204 ± 0.000^b
UAE	0.345 ± 0.021^a	0.327 ± 0.005^a	0.475 ± 0.005^a	0.314 ± 0.046^a
Abbreviations: aISO, aglycone isoflavones; cISO, conjugated isoflavones; aDAI, daidzein; cDAI, conjugated daidzein; aGly, glycitein; cGly, conjugated glycitein; aGEN, genistein; cGEN, conjugated genistein; Data represent mean values ± standard deviation (n = 3). Values followed by the same letters within a column are not significantly different (p > 0.05). *significant at p < 0.05.
ORAC	0.8846*	0.9273*	0.8899*	0.8332*
ABTS	0.8471*	0.8860*	0.8436*	0.8053*

Table 2. Aglycone to conjugated isoflavone ratio as an index of antioxidant potential

Ratio

aISO/cISO

aDAI/cDAI

aGLY/cGLY

aGEN/cGEN

Abbreviations: aISO, aglycone isoflavones; cISO, conjugated isoflavones; aDAI, daidzein; cDAI, conjugated daidzein; aGly, glycitein; cGly, conjugated glycitein; aGEN, genistein; cGEN, conjugated genistein; Data represent mean values ± standard deviation (n = 3). Values followed by the same letters within a column are not significantly different (p > 0.05). *significant at p < 0.05.

feedstock

0.068 ± 0.003^d

0.063 ± 0.002^d

0.105 ± 0.005^d

0.053 ± 0.001^d

control

0.120 ± 0.006^c

0.132 ± 0.009^c

0.146 ± 0.005^c

0.102 ± 0.015^c

HAE

0.258 ± 0.002^b

0.268 ± 0.003^b

0.404 ± 0.005^b

0.204 ± 0.000^b

UAE

0.345 ± 0.021^a

0.327 ± 0.005^a

0.475 ± 0.005^a

0.314 ± 0.046^a

Correlation

ORAC

0.8846*

0.9273*

0.8899*

0.8332*

ABTS

0.8471*

0.8860*

0.8436*

0.8053*