Publications by authors named "Kjersti Aaby"

30 Publications

  • Page 1 of 1

Major-effect candidate genes identified in cultivated strawberry (Fragaria × ananassa Duch.) for ellagic acid deoxyhexoside and pelargonidin-3-O-malonylglucoside biosynthesis, key polyphenolic compounds.

Hortic Res 2020 Aug 1;7(1):125. Epub 2020 Aug 1.

Department of Genetics, Genomics and Breeding, NIAB-EMR, East Malling, ME19 6BJ, Kent, UK.

Strawberries are rich in polyphenols which impart health benefits when metabolized by the gut microbiome, including anti-inflammatory, neuroprotective, and antiproliferative effects. In addition, polyphenolic anthocyanins contribute to the attractive color of strawberry fruits. However, the genetic basis of polyphenol biosynthesis has not been extensively studied in strawberry. In this investigation, ripe fruits from three cultivated strawberry populations were characterized for polyphenol content using HPLC-DAD-MS and genotyped using the iStraw35k array. GWAS and QTL analyses identified genetic loci controlling polyphenol biosynthesis. QTL were identified on four chromosomes for pelargonidin-3-O-malonylglucoside, pelargonidin-3-O-acetylglucoside, cinnamoyl glucose, and ellagic acid deoxyhexoside biosynthesis. Presence/absence of ellagic acid deoxyhexoside and pelargonidin-3-O-malonylglucoside was found to be under the control of major gene loci on LG1X2 and LG6b, respectively, on the F. × ananassa linkage maps. Interrogation of gene predictions in the F. vesca reference genome sequence identified a single candidate gene for ellagic acid deoxyhexoside biosynthesis, while seven malonyltransferase genes were identified as candidates for pelargonidin-3-O-malonylglucoside biosynthesis. Homologous malonyltransferase genes were identified in the F. × ananassa 'Camarosa' genome sequence but the candidate for ellagic acid deoxyhexoside biosynthesis was absent from the 'Camarosa' sequence. This study demonstrated that polyphenol biosynthesis in strawberry is, in some cases, under simple genetic control, supporting previous observations of the presence or absence of these compounds in strawberry fruits. It has also shed light on the mechanisms controlling polyphenol biosynthesis and enhanced the knowledge of these biosynthesis pathways in strawberry. The above findings will facilitate breeding for strawberries enriched in compounds with beneficial health effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41438-020-00347-4DOI Listing
August 2020

Ellagic acid and urolithin A modulate the immune response in LPS-stimulated U937 monocytic cells and THP-1 differentiated macrophages.

Food Funct 2020 Sep;11(9):7946-7959

Nofima AS, Osloveien 1, 1433 ÅS, Norway.

Dietary polyphenols are subjected, following ingestion, to an extensive metabolism, and the molecules that act at the cellular and tissue level will be, most likely, metabolites rather than native polyphenols. The mechanisms behind the positive effects exerted by polyphenols are not yet completely elucidated, since most in vitro studies use unmetabolised polyphenols rather than the metabolites present in the body. The aim of this study was to investigate and compare the potential effect of phenolic metabolites on the immune response using U937 monocyte and THP-1 macrophage cell cultures. Of the 16 metabolites tested, urolithins (Uro), and Uro A, in particular were the most potent, showing a modest increase in basal NF-κB activity and a reduction in lipopolysaccaride (LPS)-induced NF-κB activity, gene expression and secretion of pro-inflammatory cytokines. Protocatechuic acid and its sulfate/glucuronide metabolites reduced LPS-induced NF-κB activity, but not IL-6 and TNF-α cytokine secretion. Interestingly, both ellagic acid and its metabolite Uro A had immunomodulating effects, although they regulated the immune response differently, and both reduced LPS-induced NF-κB activity in U937 cells. However, while Uro A dramatically reduced IL-6 and IL-10 mRNA expression, no effect could be observed with ellagic acid. In THP-1 cells, treatment with ellagic acid dramatically reduced the expression of Toll-like receptor 4, while Uro A had no effect. The dual role observed for Uro A, showing both a modest increase in basal NF-κB activity and a reduction in LPS-induced NF-κB activity, as well as a reduction in LPS-induced pro-inflammatory cytokine secretion, makes this metabolite particularly interesting for further studies in animals and humans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c9fo03008eDOI Listing
September 2020

Major-effect candidate genes identified in cultivated strawberry ( ×  Duch.) for ellagic acid deoxyhexoside and pelargonidin-3--malonylglucoside biosynthesis, key polyphenolic compounds.

Hortic Res 2020 1;7:125. Epub 2020 Aug 1.

Department of Genetics, Genomics and Breeding, NIAB-EMR, East Malling, ME19 6BJ Kent, UK.

Strawberries are rich in polyphenols which impart health benefits when metabolized by the gut microbiome, including anti-inflammatory, neuroprotective, and antiproliferative effects. In addition, polyphenolic anthocyanins contribute to the attractive color of strawberry fruits. However, the genetic basis of polyphenol biosynthesis has not been extensively studied in strawberry. In this investigation, ripe fruits from three cultivated strawberry populations were characterized for polyphenol content using HPLC-DAD-MS and genotyped using the iStraw35k array. GWAS and QTL analyses identified genetic loci controlling polyphenol biosynthesis. QTL were identified on four chromosomes for pelargonidin-3--malonylglucoside, pelargonidin-3--acetylglucoside, cinnamoyl glucose, and ellagic acid deoxyhexoside biosynthesis. Presence/absence of ellagic acid deoxyhexoside and pelargonidin-3--malonylglucoside was found to be under the control of major gene loci on LG1X2 and LG6b, respectively, on the  ×  linkage maps. Interrogation of gene predictions in the reference genome sequence identified a single candidate gene for ellagic acid deoxyhexoside biosynthesis, while seven malonyltransferase genes were identified as candidates for pelargonidin-3--malonylglucoside biosynthesis. Homologous malonyltransferase genes were identified in the  ×  'Camarosa' genome sequence but the candidate for ellagic acid deoxyhexoside biosynthesis was absent from the 'Camarosa' sequence. This study demonstrated that polyphenol biosynthesis in strawberry is, in some cases, under simple genetic control, supporting previous observations of the presence or absence of these compounds in strawberry fruits. It has also shed light on the mechanisms controlling polyphenol biosynthesis and enhanced the knowledge of these biosynthesis pathways in strawberry. The above findings will facilitate breeding for strawberries enriched in compounds with beneficial health effects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41438-020-00347-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7395118PMC
August 2020

Effect of temperature on stability of anthocyanins, ascorbic acid and color in strawberry and raspberry jams.

Food Chem 2020 Jun 30;316:126297. Epub 2020 Jan 30.

Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Osloveien 1, N-1433 Ås, Norway.

Strawberry (cv. Senga Sengana) and raspberry (cv. Veten) were processed into jams at 60, 85 or 93 °C and stored at 4 or 23 °C for 8 and 16 weeks. High processing temperature reduced ascorbic acid, total monomeric anthocyanins (TMA) and total phenolics (TP) in strawberries (p<0.05), but not in raspberries. Processing temperature had minor effect on bioactive compounds in the jams during storage (<10% explained variance), but influenced color (L*, °Hue, Chroma), especially L* of the strawberry jams (73.3%). Storage period explained most of the variance in ascorbic acid (>90%), TMA (>42%) and TP (>69%). Storage temperature affected stability of anthocyanins, but had minor effect on ascorbic acid, which declined rapidly independent of storage temperature. Storage temperature also explained most of the variance (>40%) in Chroma of the jams and L* of raspberry jams (53%). Bioactive compounds and color were more stable in raspberry jams than in strawberry jams.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.foodchem.2020.126297DOI Listing
June 2020

A Review of Factors Affecting Anthocyanin Bioavailability: Possible Implications for the Inter-Individual Variability.

Foods 2019 Dec 18;9(1). Epub 2019 Dec 18.

Department of Metabolism and Nutrition, Institute of Food Science, Technology and Nutrition (ICTAN-CSIC), Jose Antonio Novais 10, 28040 Madrid, Spain.

Anthocyanins are dietary bioactive compounds showing a range of beneficial effects against cardiovascular, neurological, and eye conditions. However, there is, as for other bioactive compounds in food, a high inter and intra-individual variation in the response to anthocyanin intake that in many cases leads to contradictory results in human trials. This variability could be caused at two levels, one at the bioavailability level and the other at the effect and mechanisms of action. In this context, we have thoroughly reviewed the scientific literature on anthocyanins variability caused by variation in bioavailability. Based on the literature reviewed, we have concluded that the variability in anthocyanins bioavailability might be produced by the lack of homogeneity introduced at three different levels: food matrix and food processing, enzymes involved in anthocyanin metabolism and transport, and anthocyanin metabolizing gut microbiota. However, it should be noted that the literature on anthocyanins bioavailability considering inter or intra-individual variability is still very scarce, which makes it difficult to reach any firm conclusion on the main metabolizing enzymes or bacteria that would be responsible for the variability in anthocyanin bioavailability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/foods9010002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023094PMC
December 2019

Application of HPLC-PDA-MS metabolite profiling to investigate the effect of growth temperature and day length on blackcurrant fruit.

Metabolomics 2019 01 8;15(1):12. Epub 2019 Jan 8.

NIBIO, Norwegian Institute of Bioeconomy Research, Pb 115, 1431, Ås, Norway.

Introduction: Blackcurrant (Ribes nigrum L.) is an excellent example of a "super fruit" with potential health benefits. Both genotype and cultivation environment are known to affect the chemical composition of blackcurrant, especially ascorbic acid and various phenolic compounds. Environmental conditions, like temperature, solar radiation and precipitation can also have significant impact on fruit chemical composition. The relevance of the study is further accentuated by the predicted and ongoing changes in global climate.

Objectives: The aim of the present study was to provide new knowledge and a deeper understanding of the effects of post flowering environmental conditions, namely temperature and day length, on fruit quality and chemical composition of blackcurrant using an untargeted high performance liquid chromatography-photo diode array-mass spectrometry (HPLC-PDA-MS) metabolomics approach.

Methods: A phytotron experiment with cultivation of single-stemmed potted plants of blackcurrant cv. Narve Viking was conducted using constant temperatures of 12, 18 or 24 °C and three different photoperiods (short day, short day with night interruption, and natural summer daylight conditions). Plants were also grown under ambient outdoor conditions. Ripe berries were analysed using an untargeted HPLC-PDA-MS metabolomics approach to detect the presence and concentration of molecules as affected by controlled climatic factors.

Results: The untargeted metabolomics dataset contained a total of 7274 deconvolved retention time-m/z pairs across both electrospray ionisation (ESI) positive and negative polarities, from which 549 metabolites were identified or minimally annotated based upon accurate mass MS. Conventional principal component analysis (PCA) in combination with the Friedman significance test were applied to first identify which metabolites responded to temperature in a linear fashion. Multi-block hierarchical PCA in combination with the Friedman significance test was secondly applied to identify metabolites that were responsive to different day length conditions. Temperature had significant effect on a total of 365 metabolites representing a diverse range of chemical classes. It was observed that ripening of the blackcurrant berries under ambient conditions, compared to controlled conditions, resulted in an increased accumulation of 34 annotated metabolites, mainly anthocyanins and flavonoids. 18 metabolites were found to be regulated differentially under the different daylength conditions. Moreover, based upon the most abundant anthocyanins, a comparison between targeted and untargeted analyses, revealed a close convergence of the two analytical methods. Therefore, the study not just illustrates the value of non-targeted metabolomics approaches with respect to the huge diversity and numbers of significantly changed metabolites detected (and which would be missed by conventional targeted analyses), but also shows the validity of the non-targeted approach with respect to its precision compared to targeted analyses.

Conclusions: Blackcurrant maturation under controlled ambient conditions revealed a number of insightful relationships between environment and chemical composition of the fruit. A prominent reduction of the most abundant anthocyanins under the highest temperature treatments indicated that blackcurrant berries in general may accumulate lower total anthocyanins in years with extreme hot summer conditions. HPLC-PDA-MS metabolomics is an excellent method for broad analysis of chemical composition of berries rich in phenolic compounds. Moreover, the experiment in controlled phytotron conditions provided additional knowledge concerning plant interactions with the environment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11306-018-1462-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326004PMC
January 2019

Effect of high pressure and thermal processing on shelf life and quality of strawberry purée and juice.

Food Chem 2018 Sep 3;260:115-123. Epub 2018 Apr 3.

Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, P.O. Box 8034, N-4068 Stavanger, Norway.

The purpose of the study was to determine the effects of high pressure processing (HPP; 400-600 MPa, 20 °C, 1.5 or 3 min) and heat treatment (HT; 85 °C for 2 min) of strawberry purée and juice made from the same raw material. Microbiological and enzymatic inactivation, Brix, pH, anthocyanins, vitamin C, colour and sensory properties were analysed after processing and cold storage. The microbiological shelf life of the products was at least 49 days when processed at 500 or 600 MPa. Anthocyanins, vitamin C and colour were well preserved after HPP and HT. During storage, anthocyanins, vitamin C and sensory quality were better conserved in HT than in HPP purées, while there were minor differences between HT and HPP juices. This was probably due to higher enzyme activity in HPP purées, and indicates that raw materials with lower initial enzyme activity, like juices, are more suited for HPP than e.g. purées.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.foodchem.2018.03.100DOI Listing
September 2018

Development, validation and evaluation of an analytical method for the determination of monomeric and oligomeric procyanidins in apple extracts.

J Chromatogr A 2017 Apr 18;1495:46-56. Epub 2017 Mar 18.

Institute of Food Research, Norwich Research Park, Norwich, UK.

There is a lack of data for individual oligomeric procyanidins in apples and apple extracts. Our aim was to develop, validate and evaluate an analytical method for the separation, identification and quantification of monomeric and oligomeric flavanols in apple extracts. To achieve this, we prepared two types of flavanol extracts from freeze-dried apples; one was an epicatechin-rich extract containing ∼30% (w/w) monomeric (-)-epicatechin which also contained oligomeric procyanidins (Extract A), the second was an oligomeric procyanidin-rich extract depleted of epicatechin (Extract B). The parameters considered for method optimisation were HPLC columns and conditions, sample heating, mass of extract and dilution volumes. The performance characteristics considered for method validation included standard linearity, method sensitivity, precision and trueness. Eight laboratories participated in the method evaluation. Chromatographic separation of the analytes was best achieved utilizing a Hilic column with a binary mobile phase consisting of acidic acetonitrile and acidic aqueous methanol. The final method showed linearity for epicatechin in the range 5-100μg/mL with a correlation co-efficient >0.999. Intra-day and inter-day precision of the analytes ranged from 2 to 6% and 2 to 13% respectively. Up to dp3, trueness of the method was >95% but decreased with increasing dp. Within laboratory precision showed RSD values <5 and 10% for monomers and oligomers, respectively. Between laboratory precision was 4 and 15% (Extract A) and 7 and 30% (Extract B) for monomers and oligomers, respectively. An analytical method for the separation, identification and quantification of procyanidins in an apple extract was developed, validated and assessed. The results of the inter-laboratory evaluation indicate that the method is reliable and reproducible.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chroma.2017.03.030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5390050PMC
April 2017

Ascorbate pool, sugars and organic acids in black currant (Ribes nigrum L.) berries are strongly influenced by genotype and post-flowering temperature.

J Sci Food Agric 2017 Mar 21;97(4):1302-1309. Epub 2016 Jul 21.

Department of Plant Sciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway.

Background: Marked effects of the climatic environment on fruit chemical composition have often been demonstrated in field experiments. However, complex covariations of several climatic factors in the natural environment complicate the interpretation of such experiments and the identification of the causal factors. This can be better achieved in a phytotron where the various climatic factors can be varied systematically. Therefore, we grew four black currant cultivars of contrasting origin in a phytotron under controlled post-flowering temperature and photoperiod conditions and analysed the berries for their ascorbic acid, sugar and organic acid contents.

Results: The analyses revealed significant effects of genotype on all investigated compounds. Particularly large cultivar differences were observed in the concentrations of l-ascorbic acid (AA) and sucrose. The concentrations of both AA and dehydroascorbic acid (DHAA), as well as the concentrations of all major sugars, decreased consistently with an increasing temperature over the temperature range 12-24 °C. Fructose and glucose were the predominant sugars with concentrations several fold higher than that for sucrose. AA was the main contributor to the total ascorbate pool in black currant berries. The AA/DHAA ratio varied from 5.6 to 10.3 among the studied cultivars. The concentration of citric acid, which was the predominant organic acid in black currant berries, increased with an increasing temperature, whereas the opposite trend was observed for malic and shikimic acid. Quninic acid was always present at relatively low concentrations. By contrast, photoperiod had no significant effect on berry content of any of the investigated compounds.

Conclusion: It is concluded that the post-flowering temperature has marked effects on the concentration of important chemical compounds responsible for taste and nutritional value of black currant berries, whereas photoperiod has no such effect in the studied cultivars. © 2016 Society of Chemical Industry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jsfa.7864DOI Listing
March 2017

Influence of Controlled Postflowering Temperature and Daylength on Individual Phenolic Compounds in Four Black Currant Cultivars.

J Agric Food Chem 2016 Feb 22;64(4):752-61. Epub 2016 Jan 22.

Department of Plant Sciences, Norwegian University of Life Sciences , NO-1432 Ås, Akershus, Norway.

The effects of postflowering temperature and daylength on the concentration of individual phenolic compounds were studied in black currant (Ribes nigrum L.) berries under controlled phytotron conditions. The four cultivars studied varied greatly in their concentrations of individual phenolic compounds and temperature stability for accumulation. The concentrations of a wide range of identified phenolic compounds were strongly influenced by temperature over the 12-24 °C range, often with opposite temperature gradient patterns for compounds within the same subclass. Accumulation of anthocyanins and flavonols increased under natural long day conditions, which provided an increased daily light integral, while under identical light energy conditions, photoperiod had little or no effect on the concentration of phenolic compounds. Furthermore, with the exception of members of the hydroxycinnamic acid subclass, the concentration of most phenolic compounds was higher in berries ripened outdoors than in the phytotron, apparently due to screening of UV-B radiation by the glass cover.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jafc.5b05966DOI Listing
February 2016

Polyphenol-rich juices reduce blood pressure measures in a randomised controlled trial in high normal and hypertensive volunteers.

Br J Nutr 2015 Oct 31;114(7):1054-63. Epub 2015 Jul 31.

Department of Nutrition,Institute of Basic Medical Sciences, University of Oslo,Sognsvannsveien 9, PO Box 1046, Blindern,0317Oslo,Norway.

Intake of fruits and berries may lower blood pressure (BP), most probably due to the high content of polyphenols. In the present study, we tested whether consumption of two polyphenol-rich juices could lower BP. In a randomised, double-blinded, placebo-controlled trial of 12 weeks, 134 healthy individuals, aged 50-70 years, with high normal range BP (130/85-139/89 mmHg, seventy-two subjects) or stage 1-2 hypertension (140/90-179/109 mmHg, sixty-two subjects), were included. They consumed 500 ml/d of one of either (1) a commercially available polyphenol-rich juice based on red grapes, cherries, chokeberries and bilberries; (2) a juice similar to (1) but enriched with polyphenol-rich extracts from blackcurrant press-residue or (3) a placebo juice (polyphenol contents 245·5, 305·2 and 76 mg/100 g, respectively). Resting BP was measured three times, with a 1 min interval, at baseline and after 6 and 12 weeks of intervention. Systolic BP significantly reduced over time (6 and 12 weeks, respectively) in the pooled juice group compared with the placebo group in the first of the three measurements, both for the whole study group (6·9 and 3·4 mmHg; P= 0·01) and even more pronounced in the hypertensive subjects when analysed separately (7·3 and 6·8 mmHg; P= 0·04). The variation in the BP measurements was significantly reduced in the pooled juice group compared with the placebo group (1·4 and 1·7 mmHg; P= 0·03). In conclusion, the present findings suggest that polyphenol-rich berry juice may contribute to a BP- and BP variability lowering effect, being more pronounced in hypertensive than in normotensive subjects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1017/S0007114515000562DOI Listing
October 2015

Validated Method for the Characterization and Quantification of Extractable and Nonextractable Ellagitannins after Acid Hydrolysis in Pomegranate Fruits, Juices, and Extracts.

J Agric Food Chem 2015 Jul 17;63(29):6555-66. Epub 2015 Jul 17.

†Research Group on Quality, Safety and Bioactivity of Plant Foods, CEBAS-CSIC, P.O. Box 164, 30100 Campus de Espinardo, Murcia, Spain.

Pomegranates are one of the main highly valuable sources of ellagitannins. Despite the potential health benefits of these compounds, reliable data on their content in pomegranates and derived extracts and food products is lacking, as it is usually underestimated due to their complexity, diversity, and lack of commercially available standards. This study describes a new method for the analysis of the extractable and nonextractable ellagitannins based on the quantification of the acid hydrolysis products that include ellagic acid, gallic acid, sanguisorbic acid dilactone, valoneic acid dilactone, and gallagic acid dilactone in pomegranate samples. The study also shows the occurrence of ellagitannin C-glycosides in pomegranates. The method was optimized using a pomegranate peel extract. To quantify nonextractable ellagitannins, freeze-dried pomegranate fruit samples were directly hydrolyzed with 4 M HCl in water at 90 °C for 24 h followed by extraction of the pellet with dimethyl sulfoxide/methanol (50:50, v/v). The method was validated and reproducibility was assessed by means of an interlaboratory trial, showing high reproducibility across six laboratories with relative standard deviations below 15%. Their applicability was demonstrated in several pomegranate extracts, different parts of pomegranate fruit (husk, peels, and mesocarp), and commercial juices. A large variability has been found in the ellagitannin content (150-750 mg of hydrolysis products/g) and type (gallagic acid/ellagic acid ratios between 4 and 0.15) of the 11 pomegranate extracts studied.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jafc.5b02062DOI Listing
July 2015

Quality and chemical composition of ten red raspberry (Rubus idaeus L.) genotypes during three harvest seasons.

Food Chem 2014 Oct 25;160:233-40. Epub 2014 Mar 25.

Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Osloveien 1, N-1430 Ås, Norway.

Colour and chemical composition of fruits of 10 red raspberry genotypes grown in Nordic climate during three harvest seasons were studied. The main phenolic compounds in the fruits were ellagitannins and anthocyanins, contributing 57% and 42% to the quantified phenolic compounds, respectively. Cyanidin-3-sophoroside was the most abundant anthocyanin (61%). All quality parameters were significantly affected by genotype. The genotypes could be categorised into three groups. 'Veten' and 'RU984 06038' were characterised by high concentrations of flavonoids, i.e., anthocyanins and quercetin glycosides, and dark red colour. 'Octavia', 'Glen Magna', 'RU004 03067', 'Glen Ample' and 'RU974 07002' were characterised by light colour, high titratable acids and low flavonoid concentrations. 'Malling Hestia', 'RU024 01003' and 'RU004 04095' had high content of dry matter, soluble solids, ascorbic acid and ellagic acid containing compounds, in addition to high hue and chroma values. All quality parameters, except ascorbic acid and lambertianin C, varied significantly between harvest seasons. The lowest seasonal variation in fruit quality was observed in 'RU024 01003' and 'Glen Ample' and the highest 'RU004 03067' and 'Glen Magna'.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.foodchem.2014.02.174DOI Listing
October 2014

Effects of ripeness and cultivar on chemical composition of strawberry (Fragaria×ananassa Duch.) fruits and their suitability for jam production as a stable product at different storage temperatures.

Food Chem 2014 Mar 25;146:412-22. Epub 2013 Sep 25.

Norwegian Institute for Agricultural and Environmental Research, Arable Crops Division, N-2849 Kapp, Norway; Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, N-1432 Aas, Norway. Electronic address:

Effects of ripeness (nearly ripe, ripe, fully ripe) and cultivar ('Blink', 'Polka' and 'Senga Sengana') on colour and chemical composition of strawberry fruits and their suitability for jam production, evaluated as stability during storage at 4 and 20°C for 3 and 6months, were investigated. Quality traits of fruits and jams were significantly affected by both ripeness stage and cultivar. However, after 6months of storage, particularly at 20°C, the effects of fruit ripeness and cultivar were considerably reduced. During jam storage, anthocyanins, ascorbic acid, chroma and hue were least stable in jams made from the least ripe fruits. Quality traits in jams made from 'Senga Sengana' were best preserved during storage, while quality and chemical composition in jams made from 'Blink' changed the most. In conclusion, fully ripe fruits were best suited for jam processing. Storage at low temperature was preferable and 'Senga Sengana' was the most and 'Blink' the least suitable cultivar for processing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.foodchem.2013.09.086DOI Listing
March 2014

Effects of bilberry (Vaccinium myrtillus) in combination with lactic acid bacteria on intestinal oxidative stress induced by ischemia-reperfusion in mouse.

J Agric Food Chem 2013 Apr 25;61(14):3468-78. Epub 2013 Mar 25.

Food Hygiene, Department of Food Technology, Engineering and Nutrition, Lund University, Lund, Sweden.

Intestinal ischemia-reperfusion (I/R) results in oxidative stress, inflammation, and tissue injuries. The present study investigates the antioxidative and anti-inflammatory effects of a dietary supplement of bilberry, either alone or in combination with Lactobacillus plantarum RESO56, L. plantarum HEAL19, or Pediococcus acidilactici JAM046, in an I/R-induced model for oxidative stress in mice. A bilberry diet without addition of bacteria significantly decreased both lipid peroxidation (p = 0.001) and mucosal injury in the ileum. Of 14 anthocyanins identified in bilberry, anthocyanin arabinosides were the most resistant to absorption and microbial degradation in the intestines. Cyanidin-3-glucoside and delphinidin-3-glucoside seemed to be mostly absorbed in the stomach and upper part of the small intestine, while malvidin-3-galactoside, peonidin-3-glucoside, peonidin-3-galactoside, and petunidin-3-galactoside seemed to be digested by the microbiota in the cecum. Bilberry strongly influenced the composition of the cecal microbiota. In conclusion, a food supplement of bilberry protected small intestine against oxidative stress and inflammation induced by ischemia-reperfusion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf400203hDOI Listing
April 2013

Antiproliferative effects of fresh and thermal processed green and red cultivars of curly kale (Brassica oleracea L. convar. acephala var. sabellica).

J Agric Food Chem 2012 Aug 17;60(30):7375-83. Epub 2012 Jul 17.

Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research , Osloveien 1, NO-1430 Ås, Norway.

Brassica vegetables contain a diverse range of phytochemicals with biological properties such as antioxidant and anticancer activity. However, knowledge about how biological activities are affected by processing is lacking. A green cultivar and a red cultivar of curly kale were evaluated for water/methanol-soluble phytochemicals before and after processing involving blanching, freeze storage, and boil-in-bag heat treatment. In both kale cultivars, processing resulted in a significant decrease of total phenolics, antioxidant capacity, and content and distribution of flavonols, anthocyanins, hydroxycinnamic acids, glucosinolates, and vitamin C. Interestingly, the red curly kale cultivar had a higher capacity to withstand thermal loss of phytochemicals. The extracts of both green and red curly kale inhibited the cell proliferation of three human colon cancer cell lines (Caco-2, HT-29, and HCT 116). However, extracts from fresh plant material had a significantly stronger antiproliferative effect than extracts from processed plant material.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf300875fDOI Listing
August 2012

Phenolic compounds in strawberry (Fragaria x ananassa Duch.) fruits: Composition in 27 cultivars and changes during ripening.

Food Chem 2012 May 18;132(1):86-97. Epub 2011 Oct 18.

Nofima AS, The Norwegian Institute of Food, Fisheries and Aquaculture Research, Osloveien 1, N-1430 Aas, Norway.

Phenolic compounds in fruits of 27 cultivars of strawberry (Fragaria x ananassa Duch.) grown in Norway were characterised and quantified by HPLC-DAD-MS(n). Total phenolic content, calculated as the sum of the individual compounds, varied 2.3-fold among cultivars, i.e., from 57 to 133mg/100g of fw. There were significant differences among cultivars in concentration of all phenolic compounds. The highest variation between cultivars was found for cinnamoyl glucose (0.6-24.9mg/100g of fw). Concentration of anthocyanins, the most abundant class of phenolic compounds in the majority of the cultivars, varied from 8.5 to 65.9mg/100g of fw. Flavan-3-ols (11-45mg/100g of fw) and ellagitannins (7.7-18.2mg/100g of fw) contributed on average 28% and 14% to total phenolic contents in the strawberry cultivars, respectively. In three cultivars harvested at three stages of ripeness, anthocyanins and cinnamic acid conjugates were the compounds most affected by ripening. The anthocyanin profile for the individual cultivars was only slightly affected by ripening and growing conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.foodchem.2011.10.037DOI Listing
May 2012

Effect of processing of black currant press-residue on polyphenol composition and cell proliferation.

J Agric Food Chem 2011 Apr 14;59(8):3632-40. Epub 2011 Mar 14.

Nofima Mat AS, Aas, Norway.

The press-residue of black currants provides a good source of phenolic antioxidants. The purpose of this study was to optimize the extraction of phenolic compounds from the press-residue by use of extraction conditions compatible with food use. The effects of temperature, extraction duration, and use of ultrasound-assisted extraction on the juice yield, total phenolics (TP), and anthocyanin content of aqueous extracts were studied. Within the variables and response factors tested, the optimal conditions were a 15 min extraction at 90 °C. No significant effect from ultrasound-assisted extraction was found. The composition of anthocyanins and polyphenols was highly dependent on the extraction temperature. The percentage contribution of delphinidin- and cyanidin-3-rutinoside to TP had a negative linear correlation with temperature, while delphinidin- and cyanidin-3-glucoside had a positive linear correlation with temperature, with a maximum amount obtained at 80 °C and 55 °C, respectively. Furthermore, extracts obtained at higher temperatures showed a stronger inhibition of proliferation of Caco-2, HT-29, and HCT 116 cells than extracts obtained at lower temperatures. This may be due to the decomposition of complex polyphenols at higher temperatures, making them more accessible to the cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf104427rDOI Listing
April 2011

Antioxidative protection of dietary bilberry, chokeberry and Lactobacillus plantarum HEAL19 in mice subjected to intestinal oxidative stress by ischemia-reperfusion.

BMC Complement Altern Med 2011 Jan 27;11. Epub 2011 Jan 27.

Food Hygiene, Department of Food Technology, Engineering and Nutrition, Lund University, Sweden.

Background: Ischemia-reperfusion (I/R) in the intestines is an inflammatory condition which activates leukocytes and reactive oxygen species (ROS) and leads to lipid peroxidation and DNA damage. Bilberry and chokeberry fruits are rich sources of polyphenols which may act as antioxidants and prevent lipid peroxidation. Lactic acid bacteria (LAB) may improve microbial status in the intestines and increase the metabolic activity towards polyphenolic degradation. The aim of the study was to clarify antioxidative effects of bilberry and chokeberry fruits alone and with addition of a LAB-strain, Lactobacillus plantarum HEAL19, in an I/R-model in mice.

Methods: Male BALB/cJ mice were fed the experimental diets for 10 days. Diets consisted of standard chow supplemented with either bilberry (Vaccinium myrtillus) or chokeberry (Aronia × prunifolia) powder alone or in combination with the LAB-strain Lactobacillus plantarum HEAL19. I/R-injury was induced by holding superior mesenteric artery clamped for 30 minutes followed by reperfusion for 240 minutes. Thereafter, colonic and caecal tissues and contents were collected. Malondialdehyde (MDA) was used as indicator of lipid peroxidation and was measured by a calorimetric assay, lactobacilli were cultured on Rogosa agar plates and Enterobacteriaceae on VRBG agar plates, anthocyanins and phenolic acids were analysed by HPLC-DAD-ESI-MSn.

Results: MDA was significantly decreased in the colon of groups fed bilberry alone (p = 0.030) and in combination with L. plantarum HEAL19 (p = 0.021) compared to the IR-control but not in chokeberry-fed groups. Supplementation with bilberry or chokeberry alone reduced the total number of lactobacilli on the mucosa. Higher concentrations of anthocyanins were found in the colon than in the caecum content of mice. A more varied composition of different anthocyanins was also observed in the colon content compared to the caecum of bilberry-fed mice. Phenolic acids formed by microbial degradation of the dietary polyphenols in the gut could be detected. More phenolic metabolites were found in the intestines of bilberry-fed mice than in the chokeberry-fed ones.

Conclusions: Bilberry alone and in combination with L. plantarum HEAL19 exerts a better protection against lipid peroxidation than chokeberry. These dietary supplements may be used to prevent or suppress oxidative stress.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1472-6882-11-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038167PMC
January 2011

Characterization, quantification, and yearly variation of the naturally occurring polyphenols in a common red variety of curly kale ( Brassica oleracea L. convar. acephala var. sabellica cv. 'Redbor').

J Agric Food Chem 2010 Nov 15;58(21):11346-54. Epub 2010 Oct 15.

Nofima Mat AS, Osloveien 1, N-1430 Aas, Norway.

This study focuses on the characterization and quantification of polyphenols in the edible leaves of red curly kale ( Brassica oleracea L. convar. acephala (DC.) Alef. var. sabellica L.), variety 'Redbor F1 hybrid'. The kale was grown at an experimental field (59° 40' N) in the years 2007-2009. The analysis of kale extract by HPLC-DAD-ESI-MS has allowed the determination of 47 different acylated and nonacylated flavonoid glycosides and complex hydroxycinnamic acids. Those compounds included mono- to tetraglycosides of quercetin, kaempferol, and cyanidin and derivatives of p-coumaric, ferulic, sinapic, and caffeic acid. Among the compounds characterized, four flavonols, three anthocyanins, and three phenolic acids were identified in the Brassica family for the first time. Aglycones and conjugated polyphenols were quantified by HPLC-DAD using commercially available standards. The main flavonol, anthocyanin, and phenolic acid were kaempferol-3-sinapoyl-diglucoside-7-diglucoside, cyanidin-3-sinapoyl-feruloyl-diglucoside-5-glucoside, and disinapoyl-diglucoside, respectively, each representing 9.8, 10.3, and 4.9% of the total amount of 872 mg polyphenol equivalents per 100 g of fresh kale. Variations between individual plants and growing seasons were of the same order of magnitude for total phenolics and total monomeric anthocyanins.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf102131gDOI Listing
November 2010

Influence of postflowering temperature on fruit size and chemical composition of Glen Ample raspberry (Rubus idaeus L.).

J Agric Food Chem 2010 Aug 26;58(16):9120-8. Epub 2010 Jul 26.

Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway.

The effects of postflowering temperature on the fruit chemical composition of Glen Ample raspberries were studied under controlled environment conditions. The berry weight decreased significantly with increasing temperature (12, 18, and 24 °C) and with progress of the harvest period. Because the moisture content increased in parallel with the berry weight, the antioxidant capacity (AOC) and the concentration of a range of bioactive compounds decreased with decreasing temperature and progress of the harvest season when expressed on a fresh weight basis in the conventional way. Under those circumstances, dry weight units are therefore preferable. However, despite the dilution effect of large berries, the concentration of ascorbic acid (vitamin C) increased with decreasing temperature, even on a fresh weight basis. Berry AOC was closely correlated with total phenolic concentration (r = 0.958), predominantly anthocyanins and ellagitannins. While a total of 10 anthocyanins were detected, cyanidin-3-sophoroside and cyanidin-3-(2(G)-glucosylrutinoside)-rutinoside accounted for 73% of the total, the former decreasing and the latter increasing with increasing growth temperature. By far, the most prevalent ellagitannins were lambertianin C and sanguiin H-6, both of which increased significantly with increasing temperature. It is concluded that the growth temperature has significant and contrasting effects on the concentration of a range of potentially bioactive compounds in raspberry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf101736qDOI Listing
August 2010

Optimization of extraction of apple pomace phenolics with water by response surface methodology.

J Agric Food Chem 2010 Aug 28;58(16):9103-11. Epub 2010 Jul 28.

Department of Food Engineering, Faculty of Engineering, Erciyes University, 38039 Kayseri, Turkey.

Response surface methodology was employed to optimize the extraction of apple pomace phenolics with water. The constructed models were adequate to explain the behavior of the extraction system and predict the responses, total phenolics, and 5-hydroxymethylfurfural. Among the studied factors, temperature, extraction time, and solvent to solid ratio had the greatest influence on the responses. Water extraction using a combination of 100 °C for temperature, 37 min for extraction time, and 100 mL/g for solvent to solid ratio provided an opportunity to extract the antioxidants of apple pomace by limiting the formation of 5-hydroxymethylfurfural. Twenty-nine phenolic compounds were characterized in apple pomace by HPLC-MS. Phenolic content of apple pomace was 8341 mg/kg of dry matter at optimized conditions, which offer an alternative, safer way to extract antioxidants than by use of organic solvents.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf1015494DOI Listing
August 2010

Characterization and quantification of flavonoids and hydroxycinnamic acids in curly kale (Brassica oleracea L. Convar. acephala Var. sabellica) by HPLC-DAD-ESI-MSn.

J Agric Food Chem 2009 Apr;57(7):2816-25

Nofima Mat AS, Osloveien 1, N-1430 Aas, Norway.

Kale is a leafy green vegetable belonging to the Brassicaceae family, a group of vegetables including cabbage, broccoli, cauliflower, and Brussels sprouts, with a high content of health-promoting phytochemicals. The flavonoids and hydroxycinammic acids of curly kale ( Brassica oleracea L. ssp. oleracea convar. acephala (DC.) Alef. var. sabellica L.), a variety of kale, were characterized and identified primarily through HPLC-DAD-ESI-MS(n) analysis. Thirty-two phenolic compounds including glycosides of quercetin and kaempferol and derivatives of p-coumaric, ferulic, sinapic, and caffeic acid were tentatively identified, providing a more complete identification of phenolic compounds in curly kale than previously reported. Moreover, three hydroxycinnamic acids and one flavonoid with an unusual high grade of glycosylation, quercetin-3-disinapoyl-triglucoside-7-diglucoside, have been tentatively identified for the first time. The influence of different extraction conditions (extraction method, solvent type, solvent/solid ratio, and duration of extraction) was investigated. The total flavonol and hydroxycinnamic acid contents in curly kale determined as rutin equivalents (RE) were 646 and 204 mg of RE/100 g of fresh weight (fw), respectively. The contents of individual flavonoids ranged from 2 to 159 mg of RE/100 g of fw, with main compounds kaempferol-3-sinapoyl-diglucoside-7-diglucoside (18.7%) and quercetin-3-sinapoyl-diglucoside-7-diglucoside (16.5%). After acidic hydrolysis, two flavonol aglycones were identified in curly kale, quercetin and kaempferol, with total contents of 44 and 58 mg/100 g of fw, respectively.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf803693tDOI Listing
April 2009

Molar absorptivities and reducing capacity of pyranoanthocyanins and other anthocyanins.

J Agric Food Chem 2007 Dec 30;55(26):10591-8. Epub 2007 Nov 30.

Department of Chemistry, University of Bergen, Norway.

To improve accuracy in the determination of anthocyanin purity and succeeding antioxidant capacity, 1H and 13C nuclear magnetic resonance spectroscopy have been combined with high-performance liquid chromatography (HPLC) equipped with a diode array detector and UV-vis spectroscopy in the analysis of anthocyanidin 3-glycosides and 5-carboxypyranoanthocyanidin 3-glycosides. The molar absoptivity (epsilon) values were found to be relatively similar, in contrast to previously reported literature values, and the average epsilon values for both anthocyanidin 3-monoglycosides and 5-carboxypyranoanthocyanidin 3-glycosides were proposed to be 22,000 and 23,000 in acidified aqueous and methanolic solutions, respectively. To assess the influence of structure on the potential antioxidant capacity of anthocyanins, the 3-glucosides of pelargonidin (1), cyanidin (2), peonidin (3), delphinidin (4), petunidin (5), malvidin (6), 5-carboxypyranopelargonidin (8), 5-carboxypyranocyanidin (9), 5-carboxypyranodelphinidin (11), 5-carboxypyranopetunidin (12), and 5-carboxypyranomalvidin (13) and the 3-galactosides of cyanidin (7) and 5-carboxypyranocyanidin (14) were examined by a ferric ion reducing antioxidant power (FRAP) assay. The reducing capacities of the individual anthocyanins were in the range of 0.9-5.2 micromol of Trolox equivalents/micromol. The two 5-carboxypyranoanthocyanins 11 and 9 and the four common anthocyanins 2, 4, 7, and 14, all possessing pyrogallol or catechol type of B rings, showed the highest antioxidant capacity measured by FRAP. However, the inclusion of the 5-hydroxyl in the D ring and just one oxygen substituent on the B ring in 8 diminished the reducing capacity considerably. Correspondingly, electrochemical behavior of 5-carboxypyranoanthocyanidin 3-glucosides and anthocyanidin 3-glucosides was derived using HPLC coupled to a coulometric array detector set from 100 to 800 mV in increments of 100 mV. The relative order of the reducing capacity of the various 5-carboxypyranoanthocyanidin 3-glucosides and anthocyanidin 3-glucosides were nearly alike, whether determined by coulometric array detection or FRAP.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf071417sDOI Listing
December 2007

Polyphenol composition and antioxidant activity in strawberry purees; impact of achene level and storage.

J Agric Food Chem 2007 Jun 6;55(13):5156-66. Epub 2007 Jun 6.

Matforsk AS, Norwegian Food Research Institute, Osloveien 1, N-1430 Aas, Norway.

In this study the impact of achenes on polyphenolic compounds, ascorbic acids, and antioxidant activities in strawberry purees at production and after storage at 6 and 22 degrees C for 8 and 16 weeks was investigated. Strawberry purees were made from flesh, berry, and achene-enriched homogenate and contained 0, 1.2, and 2.9% achenes, respectively. At production, strawberry purees made from flesh contained more anthocyanins, p-coumaroyl glycosides, and ascorbic acids, whereas increasing achene levels caused increasing levels of ellagic acid derivatives, proanthocyanidins, flavonols, total phenolics (TP), and antioxidant activities. In addition, the anthocyanins, TP, and ferric reducing ability power (FRAP) in purees with more achenes were better retained during storage. Ascorbic acids and anthocyanins declined rapidly during storage, whereas other polyphenols and antioxidant activities were more stable; that is, the contributions from anthocyanins and ascorbic acids to TP and antioxidant activities decreased. The findings that achenes contributed significantly to polyphenol content and stability of strawberry purees may be interesting in a nutritional and, thus, commercial, perspective.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf070467uDOI Listing
June 2007

Characterization of phenolic compounds in strawberry (Fragaria x ananassa) fruits by different HPLC detectors and contribution of individual compounds to total antioxidant capacity.

J Agric Food Chem 2007 May 2;55(11):4395-406. Epub 2007 May 2.

Matforsk AS, Norwegian Food Research Institute, Osloveien 1, N-1430 Aas, Norway.

Phenolic compounds in strawberry (Fragaria x ananassa) fruits were identified and characterized by using the complementary information from different high-performance liquid chromatography detectors: diode array, mass spectrometer in positive and negative mode, and coulometric array. Electrochemical profiles obtained from the coulometric array detector contributed to the structural elucidation suggested from the UV-vis and mass spectra. About 40 phenolic compounds including glycosides of quercetin, kaempferol, cyanidin, pelargonidin, and ellagic acid, together with flavanols, derivatives of p-coumaric acid, and ellagitannins, were described, providing a more complete identification of phenolic compounds in strawberry fruits. Quercetin-3-malonylhexoside and a deoxyhexoside of ellagic acid were reported for the first time. Antioxidative properties of individual components in strawberries were estimated by their electrochemical responses. Ascorbic acid was the single most important contributor to electrochemical response in strawberries (24%), whereas the ellagitannins and the anthocyanins were the groups of polyphenols with the highest contributions, 19 and 13% at 400 mV, respectively.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf0702592DOI Listing
May 2007

Phenolic composition and antioxidant activities in flesh and achenes of strawberries (Fragaria ananassa).

J Agric Food Chem 2005 May;53(10):4032-40

Matforsk AS, Norwegian Food Research Institute, Osloveien 1, N-1430 Aas, Norway.

High performance liquid chromatography coupled with diode array and coulometric array detectors were used to characterize and quantify phenolic compounds in achenes and flesh of ripe strawberries (cv Totem and Puget Reliance). Total phenolics and total monomeric anthocyanins were measured and antioxidant activities were evaluated by the FRAP and the ORAC assays. Strawberries contained 1% achenes on a fresh weight basis; however, they contributed to about 11% of total phenolics and 14% of antioxidant activities in strawberries. Ellagic acid, ellagic acid glycosides, and ellagitannins were the main contributors to the antioxidant activities of achenes. The major anthocyanin in flesh was pelargonidin-3-glucoside, whereas achenes consisted of nearly equal amounts of cyanidin-3-glucoside and pelargonidin-3-glucoside. Phenolic content and antioxidant activity of strawberry achenes were reduced by industrial processing. However, the levels were still high and strawberry waste byproduct could thus be a possible source of nutraceuticals or natural antioxidants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf048001oDOI Listing
May 2005

Analysis of flavonoids and other phenolic compounds using high-performance liquid chromatography with coulometric array detection: relationship to antioxidant activity.

J Agric Food Chem 2004 Jul;52(15):4595-603

Matforsk, Norwegian Food Research Institute, Osloveien 1, N-1430 Aas, Norway.

High-performance liquid chromatography coupled with a coulometric array detector was used to characterize the electrochemical behavior of 17 flavonoids and three cinnamic acid derivatives. The antioxidant activity of these phenolic compounds was evaluated by the ferric reducing activity power (FRAP), the oxygen radical absorbance capacity (ORAC), and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assays. All flavonoids, except kaempferol-3-rutinoside, malvidin-3-glucoside, and peonidin-3-glucoside, had two oxidation potentials (100-300 and 700-800 mV). Quercetin and myricetin had an additional oxidation wave at 400 mV. The electrochemical responses at a relatively low oxidation potential (300 mV) and the cumulative responses at medium oxidation potentials (400 and 500 mV) had the highest correlations with antioxidant activities. The highest correlations between electrochemical characteristics and antioxidant activities were found between electrochemical responses and antioxidant activities obtained in the FRAP assay and in the DPPH assay after short reaction periods. Lower correlations were revealed between electrochemical responses and antioxidant activities obtained in the ORAC assay.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/jf0352879DOI Listing
July 2004

Commercial antioxidants control lipid oxidation in mechanically deboned turkey meat.

Meat Sci 2003 Nov;65(3):1147-55

MATFORSK-Norwegian Food Research Institute, Osloveien 1, N-1430 Aas, Norway.

Effects of commercial rosemary antioxidants on oxidative stability of mechanically deboned turkey meat (MDTM) compared with Trolox C (vitamin E), ascorbic acid (vitamin C) and control without antioxidant were investigated. Antioxidants were added to meat at three levels. Thiobarbituric acid (TBA) assay and dynamic headspace gas chromatography were used to assess the effects of commercial antioxidants on lipid stability of MDTM during 7 months of frozen storage. Increased levels of TBA-reactive substances (TBARS) and volatile carbonyl compounds were noticed in all meat samples during storage, however most distinctly in meat without antioxidants. Retarding effect of antioxidants on the development of oxidation depended on the level and type antioxidants. Trolox C-a water soluble, synthetic derivative of vitamin E possessed the greatest antioxidative activity reflected by the lowest values of TBARS and volatile compounds. Ascorbic acid was less efficient than Trolox C and Biolox HT-W (rosemary), but more potent than most rosemary extracts in suppressing lipid oxidation especially in the long term frozen storage MDTM. The DPPH() method confirmed that antioxidant activity depends on the concentration of active compounds present in the samples available to scavenge the free radicals formed during the storage period. Supplementation of MDTM with antioxidants could be an alternative method to prevent oxidative degradation of the meat during frozen storage when vacuum packaging is not practical.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/S0309-1740(02)00345-5DOI Listing
November 2003

Quality of comminuted sausages formulated from mechanically deboned poultry meat.

Meat Sci 2002 May;61(1):73-84

MATFORSK-Norwegian Food Research Institute, Osloveien 1, N-1430 Aas, Norway.

Comminuted sausages formulated with mechanically deboned poultry meat-MDPM (turkey or chicken, frame or neck) treated in different ways before production (vacuum packed MDPM or air packed skeletons deboned at production) and stored frozen for 6 or 18 weeks have been studied using a full-factorial design and chemical, physical and sensory analysis. MDPM was obtained from a Beehive separator. Comminuted sausages with MDPM from turkey frames, stored at -25 °C as skeletons, packed in air for 18 weeks developed marked rancid odour and flavour which could also be detected by thiobarbituric acid reactive substances (TBARS) and the concentration of volatile compounds. Vacuum packed mechanically deboned meat irrespective of species and carcass part could be stored for up to 18 weeks and used in formulation of sausages without any serious changes in their sensory profiles. Instrumental colour differences between sausages were mainly due to species. Turkey sausages were darker, redder and less yellow than chicken sausages. Moisture and fat contents were influenced by carcass part and to a lesser extent depended on species and storage time. Principal least squares regression (PLS2) showed close relationships between instrumental parameters and sensory attributes. TBARS, hexanal and volatile compounds were highly correlated with rancid flavour while redness (a(∗)) was strongly related to sensory colour hue and colour strength.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/s0309-1740(01)00167-xDOI Listing
May 2002
-->