Effects of Antioxidants on Rapeseed Oil Oxidation in an Artificial Digestion Model Analyzed by UHPLC–ESI–MS

A normal diet contains large quantities of oxidized fatty acids, glycerolipids, cholesterol, and their cytotoxic degradation products because many foods in the diet are fried, heated, or otherwise processed and consumed often after long periods of storage. There is also evidence that the acid medium of the stomach promotes lipid peroxidation and that the gastrointestinal tract is a major site of antioxidant action, as demonstrated by various colorimetric methods. The identity and yields of specific products of lipid transformation have seldom been determined. The present study describes the molecular species profiles of all major gastrointestinal lipids formed during digestion of autoxidized rapeseed oil in an artificial digestion model in the presence of l-ascorbic acid, 6-palmitoyl-<i>O</i>-l-ascorbic acid, 3,5-di-<i>tert</i>-butyl-4-hydroxytoluene (BHT), dl-α-tocopherol, and dl-α-tocopheryl acetate. Differences in oxidized lipid profiles were detected in the samples digested in the presence of different antioxidants, but none of them could prevent the formation of oxidized lipids or promote their degradation in a gastric digestion model. The lack of effect is attributed to the inappropriate nature of the gastrointestinal medium for the antioxidant activity of these vitamins and BHT. A fast ultrahigh performance liquid chromatographic–electrospray ionization–mass spectrometric method was developed for the analysis of lipolysis products, including epoxy, hydroperoxy, and hydroxy fatty acids, and acylglycerols, utilizing lithium as ionization enhancer

Red/Green Currant and Sea Buckthorn Berry Press Residues as Potential Sources of Antioxidants for Food Use

The potential for using extracts of press residues from black, green, red, and white currants and from sea buckthorn berries as sources of antioxidants for foods use was investigated. Press residues were extracted with ethanol in four consecutive extractions, and total Folin–Ciocalteu (F–C) reactive material and authentic phenolic compounds were determined. Radical quenching capability and mechanisms were determined from total peroxyl radical-trapping antioxidant capacity (TRAP) and oxygen radical absorbance capacity (ORAC) assays and from diphenyl­picrylhydrazyl (DPPH) kinetics, respectively; specific activities were normalized to F–C reactive concentrations. Levels of total F–C reactive materials in press residue extracts were higher than in many fruits and showed significant radical quenching activity. Black currant had the highest authentic phenol content and ORAC, TRAP, and DPPH reactivity. Sea buckthorn grown in northern Finland showed extremely high total specific DPPH reactivity. These results suggest that berry press residues offer attractive value-added products that can provide antioxidants for use in stabilizing and fortifying foods

Red/Green Currant and Sea Buckthorn Berry Press Residues as Potential Sources of Antioxidants for Food Use

The potential for using extracts of press residues from black, green, red, and white currants and from sea buckthorn berries as sources of antioxidants for foods use was investigated. Press residues were extracted with ethanol in four consecutive extractions, and total Folin–Ciocalteu (F–C) reactive material and authentic phenolic compounds were determined. Radical quenching capability and mechanisms were determined from total peroxyl radical-trapping antioxidant capacity (TRAP) and oxygen radical absorbance capacity (ORAC) assays and from diphenyl­picrylhydrazyl (DPPH) kinetics, respectively; specific activities were normalized to F–C reactive concentrations. Levels of total F–C reactive materials in press residue extracts were higher than in many fruits and showed significant radical quenching activity. Black currant had the highest authentic phenol content and ORAC, TRAP, and DPPH reactivity. Sea buckthorn grown in northern Finland showed extremely high total specific DPPH reactivity. These results suggest that berry press residues offer attractive value-added products that can provide antioxidants for use in stabilizing and fortifying foods

Red/Green Currant and Sea Buckthorn Berry Press Residues as Potential Sources of Antioxidants for Food Use

The potential for using extracts of press residues from black, green, red, and white currants and from sea buckthorn berries as sources of antioxidants for foods use was investigated. Press residues were extracted with ethanol in four consecutive extractions, and total Folin–Ciocalteu (F–C) reactive material and authentic phenolic compounds were determined. Radical quenching capability and mechanisms were determined from total peroxyl radical-trapping antioxidant capacity (TRAP) and oxygen radical absorbance capacity (ORAC) assays and from diphenyl­picrylhydrazyl (DPPH) kinetics, respectively; specific activities were normalized to F–C reactive concentrations. Levels of total F–C reactive materials in press residue extracts were higher than in many fruits and showed significant radical quenching activity. Black currant had the highest authentic phenol content and ORAC, TRAP, and DPPH reactivity. Sea buckthorn grown in northern Finland showed extremely high total specific DPPH reactivity. These results suggest that berry press residues offer attractive value-added products that can provide antioxidants for use in stabilizing and fortifying foods

Red/Green Currant and Sea Buckthorn Berry Press Residues as Potential Sources of Antioxidants for Food Use

The potential for using extracts of press residues from black, green, red, and white currants and from sea buckthorn berries as sources of antioxidants for foods use was investigated. Press residues were extracted with ethanol in four consecutive extractions, and total Folin–Ciocalteu (F–C) reactive material and authentic phenolic compounds were determined. Radical quenching capability and mechanisms were determined from total peroxyl radical-trapping antioxidant capacity (TRAP) and oxygen radical absorbance capacity (ORAC) assays and from diphenyl­picrylhydrazyl (DPPH) kinetics, respectively; specific activities were normalized to F–C reactive concentrations. Levels of total F–C reactive materials in press residue extracts were higher than in many fruits and showed significant radical quenching activity. Black currant had the highest authentic phenol content and ORAC, TRAP, and DPPH reactivity. Sea buckthorn grown in northern Finland showed extremely high total specific DPPH reactivity. These results suggest that berry press residues offer attractive value-added products that can provide antioxidants for use in stabilizing and fortifying foods

Characterization of Metabolite Profiles of Leaves of Bilberry (Vaccinium myrtillus L.) and Lingonberry (Vaccinium vitis-idaea L.)

Leaves of bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.) are potential raw materials for food and health care products. Targeted (HPLC-DAD, HPLC-MS, and GC-FID) and nontargeted (¹H NMR) approaches were applied to study the metabolomic profiles of these leaves. Chlorogenic acid was the major phenolic compound in bilberry leaves and arbutin in lingonberry leaves. Flavonol glycosides were another major group of phenolics in bilberry [5–28 mg/g DM (dry mass)] and lingonberry (15–20 mg/g DM) leaves. Contents of fatty acids were analyzed using GC-FID. The changes in the metabolomics profile during the season were apparent in bilberry but not lingonberry leaves. Negative correlation was found between the contents of lipids and phenolics. The consistency between the key results obtained by targeted and nontargeted analyses suggests nontargeted metabolomic analysis is an efficient tool for fast screening of various leaf materials

Identification and Quantification of Avenanthramides and Free and Bound Phenolic Acids in Eight Cultivars of Husked Oat (<i>Avena sativa L</i>) from Finland

Finland is the second largest oat producer in Europe. Despite the existing knowledge of phenolics in oat, there is little information on the phenolic composition of oats from Finland. The aim of the study was to investigate the concentrations of free and bound phenolic acids, as well as avenanthramides in eight Finnish cultivars of husked oat (<i>Avena sativa</i> L.). Seven phenolic acids and one phenolic aldehyde were identified, including, in decreasing order of abundance: <i>p</i>-coumaric, ferulic, cinnamic, syringic, vanillic, 2,4-dihydroxybenzoic, and <i>o</i>-coumaric acids and syringaldehyde. Phenolic acids were mostly found as bound compounds. Significant varietal differences (<i>p</i> < 0.05) were observed in the cumulative content of phenolic acids, with the lowest level found in cv. ‘Viviana’ (1202 ± 52.9 mg kg^–1) and the highest in cv. ‘Akseli’ (1687 ± 80.2 mg kg^–1). Avenanthramides (AVNs) 2a, 2p, and 2f were the most abundant. Total AVNs levels ranged from 26.7 ± 1.44 to 185 ± 12.5 mg kg^–1 in cv. ‘Avetron’ and ‘Viviana’, respectively

Identification and Quantification of Avenanthramides and Free and Bound Phenolic Acids in Eight Cultivars of Husked Oat (<i>Avena sativa L</i>) from Finland

Finland is the second largest oat producer in Europe. Despite the existing knowledge of phenolics in oat, there is little information on the phenolic composition of oats from Finland. The aim of the study was to investigate the concentrations of free and bound phenolic acids, as well as avenanthramides in eight Finnish cultivars of husked oat (<i>Avena sativa</i> L.). Seven phenolic acids and one phenolic aldehyde were identified, including, in decreasing order of abundance: <i>p</i>-coumaric, ferulic, cinnamic, syringic, vanillic, 2,4-dihydroxybenzoic, and <i>o</i>-coumaric acids and syringaldehyde. Phenolic acids were mostly found as bound compounds. Significant varietal differences (<i>p</i> < 0.05) were observed in the cumulative content of phenolic acids, with the lowest level found in cv. ‘Viviana’ (1202 ± 52.9 mg kg^–1) and the highest in cv. ‘Akseli’ (1687 ± 80.2 mg kg^–1). Avenanthramides (AVNs) 2a, 2p, and 2f were the most abundant. Total AVNs levels ranged from 26.7 ± 1.44 to 185 ± 12.5 mg kg^–1 in cv. ‘Avetron’ and ‘Viviana’, respectively