Enhancing the functional properties of soymilk residues (okara) by solid-state fermentation with Actinomucor elegans

Figures & data

Figure 1. Lactophenol cotton blue stain revealed distinct microscopic features of DCY-1 (magnification, ×40) (a and b), and parsimonious tree was obtained from ITS sequences data, showing the relationships of strain DCY-1 compared with relevant collection strains or ITS sequences (c).

Figura 1. La mancha azul algodón de Lactophenol reveló distintas características microscopicas de DCY-1 (magnificación, ×40) (a y b) y el árbol parsimonioso se obtuvo de las secuencias de datos ITS, mostrando las relaciones de la cepa DCY-1 en comparación con las cepas recogidas o secuencias ITS (c).

Table 1. Antioxidant activities of the water extract of soymilk residues at different periods.

Tabla 1. Actividades antioxidantes del extracto de agua de los residuos de leche de soja en diferentes periodos.

Antioxidant properties	Fermentation time (h)
	0	24	36	48	60
Reducing power (µg VCE/g dw)	132.70 ± 6.34^d	282.51 ± 16.24^c	415.31 ± 17.10^b	575.83 ± 23.78^a	569.63 ± 19.83^a
DPPH scavenging activity (µg VCE/g dw)	159.73 ± 19.17^d	232.14 ± 20.98^c	501.48 ± 9.93^b	541.41 ± 8.35^a	550.54 ± 3.61^a
ABTS·^+ scavenging activity (µg VCE/g d w)	2778.56 ± 179.34^d	2983.52 ± 48.54^c	3803.34 ± 59.78^b	4127.86 ± 59.78^a	4298.66 ± 93.94^a
Hydroxyl scavenging activity (µg VCE/g dw)	16874.01 ± 263.74^d	20288.18 ± 191.29^c	26201.12 ± 121.72^b	27266.20 ± 344.88^a	27570.51 ± 182.59^a
Chelating ability (µmol EDTA-2Na/g dw)	567.77 ± 10.53^d	871.17 ± 15.34^c	1171.17 ± 13.17^b	1309.42 ± 15.66^a	1319.57 ± 17.08^a

Values are presented as means ± SD (n = 3), and means in the same row with different lower case letters (a, b, c, d) are significantly different (p < 0.05).

Figure 2. In vitro ACE-inhibitory activity of fermented okara at different fermentation periods. Means with different lower case letters (a, b, c, d, and e) indicate significant difference (p < 0.05) among the different fermentation periods of okara.

Figura 2. Actividad inhibitoria ACE in vitro de okara fermentada en diferentes periodos de fermentación. Los promedios con distintas letras minúsculas (a, b, c, d y e) indican diferencias significativas (p < 0,05) entre los diferentes periodos de fermentación de la okara.

Figure 3. Changes in protease activity and peptide content of okara at different fermentation periods. Means with different lower case letters (a, b, c, and d) indicate significant difference (p < 0.05) among the different fermentation periods of okara.

Figura 3. Cambios en la actividad de las proteasas y el contenido de péptidos de la okara en los diferentes periodos de fermentación. Los promedios con distintas letras minúsculas (a, b, c y d) indican diferencias significativas (p < 0,05) entre los diferentes periodos de fermentación de la okara.

Figure 4. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) profiles of fermented okara at different fermentation periods. Lanes 1–5 represent the samples fermented at 0, 24, 36, 48, and 60 h, respectively. Lane 6 represents the molecular weight marker.

Figura 4. Perfiles electroforéticos del gel de poliacrilamida dodecil sulfato de sodio (SDS-PAGE) de okara fermentada en diferentes periodos de fermentación. Las barras 1–5 representan las muestras fermentadas a 0, 24, 36, 48 y 60 h, respectivamente. La barra 6 representa el marcador de peso molecular.

Figure 5. Reverse phase high-performance liquid chromatography (RP-HPLC) profiles of fermented okara at different periods.

Figura 5. Perfiles cromatográficos líquidos de alta resolución de fase inversa (RP-HPLC) de okara fermentada en diferentes periodos.

Table 2. Relationship of peptide content with antioxidant and ACE-inhibitory activities.

Tabla 2. Relación del contenido de péptidos con las actividades antioxidantes y inhibitorias ACE.

Parameters	R^2
Reducing power vs. peptide content	0.8576*
DPPH scavenging activity vs. peptide content	0.9863**
ABTS scavenging activity vs. peptide content	0.9603**
·OH scavenging activity vs. peptide content	0.9400**
Fe^2^+-chelating activity vs. peptide content	0.8814*
ACE inhibition activity vs. peptide content	0.8574*

* Correlation is significant at the 0.05 level (two-tailed).

** Correlation is significant at the 0.01 level (two-tailed).

Figure 6. Relationship of protease activity and peptide content.

Figura 6. Relación de la actividad de las proteasas y el contenido de péptidos.