Antioxidant activity of alkylresorcinols from rye bran and their protective effects on cell viability of PC-12 AC cells.

Alkylresorcinols (ARs) are phenolic lipids that are present in high amounts in the bran layer of different cereals. Rye samples, cultivar Hazlet, and a white rye genotype, RT202, were analyzed for their antioxidant properties and AR content and composition, based on six fractions of the bran, where 1 was the outermost fraction and 6 was the bran fraction closest to the endosperm. Gas chromatography-mass spectrometry (GC-MS) analysis demonstrated that the most commonly found AR homologue in Hazlet rye is C19:0 and that the total amount of ARs decreases from the outermost to innermost fractions. The antioxidant activity using oxygen radical absorbance capacity (ORAC) for both white rye genotype RT202 and Hazlet brans was determined to decrease from the outermost fraction (136.05 µmol TE/g for Hazlet fraction 1 and 186.57 µmol TE/g for white rye genotype RT202 fraction 1) to the innermost fraction (9.84 µmol TE/g for Hazlet fraction 6 and 78.75 µmol TE/g for white rye genotype RT202 fraction 2). A positive relationship was seen with GC-MS results. Treatment of PC-12 AC cells with Hazlet fraction 1 increased mitochondrial biogenesis as determined using mitochondrial fluorescent dyes. In the presence of a prooxidant (AAPH), PC-12 AC cells were better protected from free radical attack when treated with Hazlet fraction 1 than with all other bran fractions. The results suggest that higher AR content in bran fractions confers antioxidant protection against free radical damage.

Patented techniques for the extraction and isolation of secoisolari-ciresinol diglucoside from flaxseed.

Plant lignans are phenolic compounds generally containing a dibenzylbutane skeleton. Secoisolariciresinol diglucoside (SDG) is the major lignan found in flaxseed. SDG is known to have antioxidant and anticancer properties. SDG can potentially be used as a natural antioxidant in foods thereby preventing further oxidation reactions and thus enhance the shelf life of foods. This article reviews the patents that are concerned with the extraction of SDG from flaxseed, the richest plant source of lignans. Most of the patented techniques for the extraction, isolation, and purification of SDG are conducted on defatted flaxseed and whole flaxseed. Flaxseed hull is potentially a good starting material. Furthermore, most methods use aliphatic alcohols (methanol, ethanol, isopropanol, butanol) to extract the complexed form of SDG. Combinations of these solvents are commonly used with water. Alkaline hydrolysis liberates SDG from its complexed form. SDG is enriched by a process involving either liquid-liquid partitioning or passing the aqueous phase through anion exchange resins or C18 resins. The SDG is recovered after evaporation of the water. Analytical HPLC coupled with mass spectrometry is performed to determine the quantity and purity of the extracted SDG.

Evaluation of antioxidant capacity and aroma quality of breast milk.

OBJECTIVE: It is important to understand the difference and similarity in antioxidant capacity and aroma quality between formula and breast milk for purposes of modifying infant formulas. We evaluated the antioxidant properties and aroma quality of infant formula and breast milk. METHODS: Six breast milk samples and four infant formulas were used. Antioxidant properties were measured using the following methods: 2,2-diphenyl-1-picryhydrazyl free radical scavenging capacity, oxygen radical absorbance capacity, total phenolic content, and phenolic composition. Aroma quality was determined using the electronic nose. RESULTS: The 2,2-diphenyl-1-picryhydrazyl free radical scavenging activity for formula and breast milk ranged from 45.3% to 61.8% and from 52.8% to 61.2%, respectively. Oxygen radical absorbance capacity ranged from 28.8 to 31.9 g/kg for formula and from 25.5 to 39.2 g/kg for breast milk. Total phenolic content ranged from 422 to 751 mg/kg and from 329to 797 mg/kg for formula and milk, respectively. p-Hydroxybenzoic acid, p-coumaric acid, and ferulic acid were detected with values ranging from 614 to 635, 1391 to 1444, and 1425 to 1490 microg/kg in breast milk and from 783 to 3594, 1449 to 1510, and 1447 to 1561 microg/kg in formulas. Electronic nose results indicated that the aroma quality of formula controls 2, 3, and 4 was similar to that of breast milk. CONCLUSION: Differences and similarities in antioxidant properties and aroma quality were found among some of the formulas and breast milk. The contribution of phenolic acids to total antioxidant capacity was limited.

AAPH-mediated antioxidant reactions of secoisolariciresinol and SDG.

Secoisolariciresinol (SECO ) is the major lignan found in flaxseed (Linum usitatissimum L.) and is present in a polymer that contains secoisolariciresinol diglucoside (SDG ). SECO, SDG and the polymer are known to have a number of health benefits, including reduction of serum cholesterol levels, delay in the onset of type II diabetes and decreased formation of breast, prostate and colon cancers. The health benefits of SECO and SDG may be partially attributed to their antioxidant properties. To better understand their antioxidant properties, SECO and SDG were oxidized using 2,2'-azobis(2-amidinopropane), an in vitro model of radical scavenging. The major lignan radical-scavenging oxidation products and their formation over time were determined. SDG was converted to four major products, which were the result of a phenoxyl radical intermediate. One of these products, a dimer of SDG, decomposed under the reaction conditions to form two of the other major products, and . SECO was converted to five major products, two of which were also the result of a phenoxyl radical intermediate. The remaining products were the result of an unexpected alkoxyl radical intermediate. The phenol oxidation products were stable under the reaction conditions, whereas two of the alcohol oxidation products decomposed. In general, only one phenol group on the lignans was oxidized, suggesting that the number of phenols per molecule may not predict radical scavenging antioxidant ability of lignans. Finally, SECO is a superior antioxidant to SDG, and it may be that the additional alcohol oxidation pathway contributes to its greater antioxidant ability.