Publications by authors named "Pirjo H Mattila"

Carrots contain a significant content of phenolic compounds, mainly phenolic acids. Technological processing of carrots inflicts wounding stress and induces accumulation of these compounds, especially caffeic acid derivatives, in the periderm tissue. In this study, the effect of minimal processing (polishing, washing, peeling, and grating) on the retention of soluble phenolic acids in carrots was monitored during cold storage.

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The aim of this study was to find new sustainable, Nordic natural antioxidant sources, develop subcritical water extraction (SWE) process for recovering the antioxidant compounds from the most potential raw materials, and to test their antioxidative effects in meat products. The antioxidant capacities of water and 50% ethanol (aq) extracts of 13 berry, grain, and horticultural plant materials as well as hexane/ethanol extracted stilbene fractions from pine heartwood and spruce inner bark were measured in hydrophilic and lipophilic systems. Tree, bilberry leaf (BL), and sea buckthorn leaf (SBL) extracts showed the highest antioxidant capacities.

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A meat model system was used for screening lipid oxidation inhibiting capacity of diverse horticultural plant materials. In the model, heme-containing sarcoplasmic proteins from the meat water-phase were homogenized with linoleic acid and thiobarbituric reactive substances (TBARS) were measured. 23 Plant materials were investigated at three high (50, 100, and 200 ppm) concentrations and five plant extracts were tested at three low (5, 10, and 20 ppm) concentrations over time.

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This study provides information on the variation of anthocyanin and flavonol contents and composition in 32 black and 12 redcurrant varieties, as well as flavonol contents and composition in two green-fruited blackcurrant (green currant) and one white currant varieties conserved in a national ex situ germplasm field collection in Finland, North Europe. Flavonols were analysed as aglycones and anthocyanins as authentic compounds using HPLC methods. In blackcurrants, total anthocyanin content varied 1260-2878mg/100g dry weight and total flavonol content 43.

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Vitamin C and polyphenol contents (anthocyanins, proanthocyanidins, phenolic acids and flavonols) were analysed in commercial blackcurrant juice products purchased from various European countries (Finland, Poland, Germany, United Kingdom) using HPLC methods. The aim was to study variation between countries, as well as evaluate the intake of polyphenols from commercial juices. There was significant variation in the contents of polyphenols and vitamin C between countries.

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According to a new European Union regulation, vitamin D(3) can be partially or totally substituted with 25-hydroxyvitamin D(3) (25-OH-D(3)) in hens' feed. The purpose of this study was to clarify how this regulation has affected the vitamin D content of commercial eggs and chicken meat. Another aim was to investigate how effectively 25-OH-D(3) is transferred from the hens' diet to egg yolk by analyzing eggs from farms using known commercial feeds and by conducting an animal study.

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The contents of extractable and unextractable proanthocyanidins were determined in a large number of commercial food products of plant origin available in Finland. Proanthocyanidins were extracted with aqueous acetone-methanol and quantified by normal phase high-performance liquid chromatography (HPLC) according to their degree of polymerization. Unextractable proanthocyanidins were analyzed from the extraction residue by reversed phase HPLC after acid-catalyzed depolymerization as free flavan-3-ols (terminal units) and benzylthioethers (extension units).

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This study developed a method for the determination of extractable and unextractable proanthocyanidins. Extractable proanthocyanidins were separated according to their degree of polymerization using normal phase HPLC. Unextractable proanthocyanidins were measured after acid-catalyzed depolymerization as flavan-3-ols (terminal units) and benzylthioethers (external units).

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Numerous in vitro and in vivo studies have suggested that dietary anthocyanins and ellagitannins or ellagic acid might have beneficial health effects. Epidemiological evidence on the disease-preventing potential of these polyphenols is lacking, due to the absence of reliable data on their contents in foods. In this study was analyzed the content of anthocyanins and ellagitannins (as ellagic acid equivalents after acid hydrolysis) in foods consumed in Finland, including berries, fruits, vegetables, and processed products, using high-performance liquid chromatographic (HPLC) methods.

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Berries contain a wide range of phenolic compounds in different conjugated forms, a fact that makes their simultaneous analysis a difficult task. In this work, soluble and insoluble phenolic compounds were identified and quantified in 18 species of berries by reversed phase high-performance liquid chromatography combined with diode array detection. The analytical results and literature data were used for the identification of the predominant conjugated hydroxycinnamic acids, flavonol glycosides, and anthocyanins in berries from six families, viz.

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