Effect of Saccharomyces cerevisiae Fermentation Process …
123
2.10 Reducing Power Activity
The reducing power was assessed by the method of Oyaizu (1986). Different concentrations of extracts (1 ml) were mixed with 2.5 ml of 0.2 M sodium phosphate buffer
(pH 6.6) and 2.5 ml of 1% potassium ferricyanide, and then the mixture was incubated at 50 °C for 20 min. Then 2.5 ml of 10% trichloroacetic acid was mixed with
each test tube and centrifuged at 1000 rpm for 10 min. The upper layer (2.5 ml)
was mixed with 2.5 ml distilled water and 0.5 ml of 0.1% of ferric chloride, and the
absorbance was recorded at 700 nm. BHT was used as standards.
2.11 Identification of Phenolic and Flavonoid Compounds
by HPLC
Separation and identification of phenolic and flavonoid compounds were carried out
by High-Performance Liquid Chromatography. The HPLC was equipped with 2487
dual λ absorbance detector, column symmetry C18, reversed phase (4.6 × 250 mm,
5 µm) (Alliance, model-2695 from Waters). A constant flow rate of 1 ml/min was
used with two mobile phases: (A) 0.1% trifluroacetic acid in HPLC grade water;
and solvent (B) 0.5% phosphoric acid in 90% acetonitrile. The chromatograms were
recorded at 280, 210 and 370 nm. The identification was carried out by retention time
using external and internal standards of the individual phenolic acids and flavonoid
compounds. The concentration of an individual compound was calculated on the
basis of peak area measurements. All solutions were HPLC grade and were filtered
prior to HPLC analysis.
Statistical Analysis
All experiments were conducted in triplicates. Results were reported as their mean
values ± standard deviation. One-way analysis of variance (ANOVA) of the data
was carried out using the Tukey HSD test. P ≤ 0.05 was considered statistically
significant.
3 Results and Discussions
3.1 Phytochemical Screening
The result of phytochemical analysis was presented in Table 1. Phytochemical analysis for unfermented and fermented flaxseed extracts showed the presence of glycerides, saponins, alkaloids and flavonoids. Tests for Sterols, terpinoids and tannins
were found to be negative. The presence of different phytochemicals in the extract
may be responsible for the therapeutic properties of flaxseed. Bekal et al. (2015)
123
2.10 Reducing Power Activity
The reducing power was assessed by the method of Oyaizu (1986). Different concentrations of extracts (1 ml) were mixed with 2.5 ml of 0.2 M sodium phosphate buffer
(pH 6.6) and 2.5 ml of 1% potassium ferricyanide, and then the mixture was incubated at 50 °C for 20 min. Then 2.5 ml of 10% trichloroacetic acid was mixed with
each test tube and centrifuged at 1000 rpm for 10 min. The upper layer (2.5 ml)
was mixed with 2.5 ml distilled water and 0.5 ml of 0.1% of ferric chloride, and the
absorbance was recorded at 700 nm. BHT was used as standards.
2.11 Identification of Phenolic and Flavonoid Compounds
by HPLC
Separation and identification of phenolic and flavonoid compounds were carried out
by High-Performance Liquid Chromatography. The HPLC was equipped with 2487
dual λ absorbance detector, column symmetry C18, reversed phase (4.6 × 250 mm,
5 µm) (Alliance, model-2695 from Waters). A constant flow rate of 1 ml/min was
used with two mobile phases: (A) 0.1% trifluroacetic acid in HPLC grade water;
and solvent (B) 0.5% phosphoric acid in 90% acetonitrile. The chromatograms were
recorded at 280, 210 and 370 nm. The identification was carried out by retention time
using external and internal standards of the individual phenolic acids and flavonoid
compounds. The concentration of an individual compound was calculated on the
basis of peak area measurements. All solutions were HPLC grade and were filtered
prior to HPLC analysis.
Statistical Analysis
All experiments were conducted in triplicates. Results were reported as their mean
values ± standard deviation. One-way analysis of variance (ANOVA) of the data
was carried out using the Tukey HSD test. P ≤ 0.05 was considered statistically
significant.
3 Results and Discussions
3.1 Phytochemical Screening
The result of phytochemical analysis was presented in Table 1. Phytochemical analysis for unfermented and fermented flaxseed extracts showed the presence of glycerides, saponins, alkaloids and flavonoids. Tests for Sterols, terpinoids and tannins
were found to be negative. The presence of different phytochemicals in the extract
may be responsible for the therapeutic properties of flaxseed. Bekal et al. (2015)