Antioxidant Effects of Water Extracts from Barley (Hordeum vulgare L.) Prepared under Different Roasting Temperatures

Abstract

The antioxidant effects of water extracts of roasted barley (WERB) were investigated under different roasting temperatures and compared with those of the water extracts of unroasted barley (WEUB). It was found that the Maillard reaction products increased upon increasing the roasting temperatures. Both WERB and WEUB exhibited significant antioxidant activities in linoleic acid and liposome model systems. Although WERB and WEUB afforded considerable protection against the damage of deoxyribose and proteins, the antioxidant efficiency of roasted samples was weaker than that of unroasted samples because of the reduction of antioxidant components (catechin, tocopherol, and lutein) with increasing roasting temperature. Unroasted samples were more effective in reducing power, quenching free radical, hydroxyl radical, and chelating iron than the roasted samples. The different antioxidant activity among roasted and unroasted barley samples may be partly attributed to the changes in catechin, tocopherol, and lutein contents.

Antioxidant, antibacterial, and anti-inflammatory activities of standardized brazilin-richCaesalpinia sappanextract

“…The reducing power was determined as described by Duh et al (2001). The samples (0.01-0.1 mg) in phosphate buffer (1.0 mL, 0.2 M, pH 6.6) were mixed with 1% potassium ferric cyanide (1 mL), and the mixtures were incubated at 50 C for 20 min.…”

“…Phenolic compounds from plants are known to possess antioxidant activities in terms of free radical scavenger, reducing power, and quencher of singlet oxygen formation (Duh et al, 2001). It is well known that antioxidant compounds can protect against several degenerative diseases, and have potential use as a dietary supplement.…”

Control of Superoxide Dismutase Activity during Malting Using Plackett-Burman and Box-Behnken Experimental Design and Its Effect on Reducing Power of Wort

“…Table I shows the maximum and minimum levels of variables chosen for trials in the Plackett-Burman experimental design for screening important factors that remarkably developed SOD activity during the malting process of Ganpi-3. Table II 8 represented eight different malting parameters. Table III shows the effect, standard error, t-ratio, P-value and confidence level of the Plackett-Burman design.…”

“…Neglecting the terms which were insignificant on the basis of regression coefficients and P-value, the linear regression equation (6) (6) where Y was the predicted response (SOD activity) from the Plackett-Burman design and X 2 , X 3 , X 8 were coded values of steeping time, germination temperature and kilning temperature, respectively.…”

“…As can be seen, the reducing power of the congress wort was much higher if the SOD activity of the corresponding malt was relatively high. Reasonable explanations were possible, such as differences of SOD activity in different malts were caused by the degree of protection reducing compounds, such as flavanoids, phenolic acids and so on that exhibited antioxidant activity through their reductive capacity in Fe 3+ -Fe 2+ and from oxidation by superoxide radical distinct during the onset of mashing 8,13 . Also possible was that, polyphenols, melanioidins and reduced thiol groups of proteins were responsible for notable variations in the reducing power in mashing 22 .…”