Browsing by Subject "antioksidantti"
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(2020)Tutkimuksen tarkoituksena oli selvittää mahdollisuuksia hyödyntää kalanjalostusteollisuuden elintarvikelaatuisia sivutuotevirtoja kalaöljyn ja rehun tuotannossa. Tässä työssä tutkittiin eri antioksidanttien vaikutusta lohen perkuujakeen säilöntätuloksiin ja pohdittiin sakan, josta öljy oli erotettu, käyttöä rehuna. Tutkimuksessa säilöttiin kasvatetun kirjolohen perkuujaetta, joka koostui sisäelimistä ja mädistä. Tutkimuksessa oli kaksi koetta. Ensimmäinen koe kesti 65 päivää ja siinä perkuujakeeseen lisättiin muurahaishappoa siten, että lopulliseksi happopitoisuudeksi saatiin 3 %. Kontrollina toimi pelkästään muurahaishappoa sisältänyt perkuujae. Koejäseninä oli neljä eri antioksidanttia: butyloitu hydroksianisoli (BHA), tert-butyyli-hydrokinoni (TBHQ), etoksikiiniseos (Helmlox) ja butyloitu hydroksitolueeni (Ionol). Ionolia annosteltiin 100 ppm ja BHA:ta, TBHQ:ta ja Helmloxia oli kokeessa kahta eri pitoisuustasoa 50 ja 100 ppm. Toinen koe kesti 29 päivää ja siinä perkuujakeen muurahaishappopitoisuus oli 1 %. Kokeessa käytettiin BHA- ja Helmlox-antioksidantteja 10 ppm annostuksella. Kokeista analysoitiin erikseen öljy- ja sakkaosat. Analyysien perusteella eri antioksidanteilla tai niiden pitoisuuksilla ei ollut vaikutusta sakan pitoisuuksiin. Ensimmäisessä kokeessa saatiin öljyosan arvoja tarkasteltaessa suurimmaksi osaksi erittäin merkitseviä (p<0,001) eroja kontrollin ja koeryhmien välille. Myös antioksidanttien välille saatiin selkeitä eroja, mutta pitoisuuksien erot eivät vaikuttaneet AV-, PV- ja TOTOX-arvoihin. Toisen kokeen öljystä saatujen pitoisuuksien erot kontrollin ja koejäsenten välillä olivat vähäiset. Antioksidanttien välillä erot olivat suuremmat kuin kontrollin ja koejäsenten välillä. Peroksidiluku oli BHA:lla selvästi suurempi kuin kontrollilla ja Helmloxilla, jolloin myös TOTOX-luku oli isompi. Tämä on kuitenkin ristiriidassa ensimmäisen kokeen tulosten kanssa. Kakkoskokeessa mitatut aminohappopitoisuudet vähenivät, kun perkuujakeeseen lisättiin antioksidanttia, mikä on ristiriidassa aiempien tutkimusten kanssa. Parhaiten antioksidanttina toimi TBHQ, seuraavaksi parhaiten BHA, jonka jälkeen Ionol ja huonoiten toimi Helmlox. Perkuujakeen sakan käyttöä sian ja broilerin rehuna rajoittaa sen suuri kalarasvapitoisuus. Kuitenkin turkiseläimille lohen perkuujae sopii rehuraaka-aineeksi, jos aminohappopuutteita täydennetään muilla rehuraaka-aineilla.
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(2020)The purpose of the study was to determine the possibilities of utilizing the by-product streams of fish processing industry in the production of fish oil and silage. In this thesis the effect of different antioxidants on the preservation of salmon scraps was studied and the utilisation of the dregs from which the oil was extracted as feed was considered. The scarps preserved in this study were from farmed salmon and consisted of internal organs and roe. The study had two experiments. The first one lasted for 65 days and in it formic acid was added to the scraps for a final acid content of 3 %. The scraps with only the formic acid acted as the control and the four different antioxidants studied were butylated hydroxyanisole (BHA), tert-butylhydroquinone (TBHQ), ethoxyquin mixture (Helmlox) and butylated hydroxytoluene (Ionol). The amount of Ionol was 100 ppm and for BHA, TBHQ and Helmlox there were two different amounts, 50 and 100 ppm. The second experiment lasted for 29 days and the formic acid content was 1 %. BHA and Helmlox antioxidants were used with an amount of 10 ppm. The oil and sediment parts from the experiments were analyzed separately. Based on the analyses the antioxidants or their amounts did not have an effect on the values extracted from the sediment. In the first experiment the analyses from the oil gave mostly highly significant (p<0,001) differences between the control and the antioxidants. There were also clear differences between the antioxidants but the different amounts did not have an effect on the AV-, PV- and TOTOX-values. In the second experiment the analyses from the oil gave only minor differences between the control and the antioxidants, the differences between different antioxidants being larger. The peroxide value of BHA was clearly larger than that of the control and Helmlox and therefore also the TOTOX-value was larger, which contradicts the results of the first experiment. In the second experiment also the measured amino acid contents diminished when the antioxidants were added which contradicts previous research. TBHQ worked best as an antioxidant, then BHA, Ionol and Helmlox in order. The usage of the dregs from the scraps as feed for pigs and chicken is limited by its high fish oil content. However for fur animals salmon scraps are suitable as feed products if the amino acid deficiencies are compensated with other feed products.
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Dietary total antioxidant capacity in relation to overall cancer incidence in a French cohort study (2013)Background: Cancer is the leading cause of death worldwide, claiming 7.6 million lives a year. Five behavioural factors have been recognised to be responsible for 30 % of the disease burden. Among them is low fruit and vegetable consumption. Fruit and vegetable consumption has been inversely associated with cancer risk but the mechanisms behind this effect are still largely debated. Dietary antioxidants present in large quantities in plant foods have been hypothesised to contribute to this protection. Objective: The aim of this study was to investigate the relationship between dietary total antioxidant capacity (TAC) and overall cancer incidence. This was done applying a new antioxidant measurement that reflects the whole set of direct antioxidant reducers (vitamin C, alpha-tocopherol, carotenoids and flavonoids) present in diet. The average TAC intake levels of the participants were assessed and the main dietary contributors to the TAC scores were examined. Subjects: Study subjects included 67 634 middle aged French women participating in an on-going prospective cohort study called E3N. Their dietary assessment was made between June 1993 and July 1995 using a semi-quantitative food frequency questionnaire able to quantitatively and qualitatively assess the average daily intake of 208 different foods, recipes and beverages. Cancer cases were self-reported and validated against medical records. The follow up of the participants ended in May 2008. Methods: Four different total antioxidant capacity scores were created using two different TAC methods, the ferric reducing ability parameter (FRAP) and the total radical-trapping antioxidant parameter (TRAP), and including or excluding coffee from the dietary TAC calculation. Coffee exclusion was justified with the fact that it is the largest contributor to the dietary TAC intake, and because of its association with some negative lifestyle behaviours, it can act as a confounder even if adjustments are made. Statistical analyses for cancer risk according to dietary TAC intake were made using Cox proportional hazards model adjusting for energy intake without alcohol, tobacco smoking, alcohol intake, BMI, physical activity level, educational background, region of residence and family history of cancer. Results: When coffee was included in the dietary TAC scores a significant but modest increase in cancer risk was observed towards higher TAC intakes (p for trend < 0.05 for both FRAP and TRAP). On the contrary, when coffee was excluded from the TAC scores a significant although modest decrease in overall cancer risk was observed (p for trend = 0.016 for both FRAP and TRAP without coffee). In the indexes where coffee was included in the score it contributed up to 43 % and 76 % of total FRAP and TRAP scores respectively. After coffee the main contributors to dietary TAC intake were tea, wine, fruits, vegetables, fruit juice and chocolate. The mean daily intake of TAC was 20.5 mmol of FRAP and 20.2 TE of TRAP in the scores including coffee. When coffee was excluded from the scores, the mean intake levels dropped to 9.4 mmol and 4.9 TE. Conclusion: Dietary total antioxidant capacity was associated with a statistically significant but modest decrease in cancer incidence when intake of coffee, the main TAC source, was not taken into account. Coffee seems to be acting as a confounding factor since when it was included in the TAC scores, there was a small but statistically significant positive association with cancer risk. For future studies it would be crucial to standardise the TAC methods so that comparisons between studies could be made. On the other hand in vitro nature of the TAC methods should be kept in mind; a fact that challenges the interpretation of the results from the biological perspective.
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(2012)Numerous scientific studies have revealed the connection between oxidative stress and a wide range of diseases, including cardiovascular, neurodegenerative, inflammatory diseases and cancer. The most probable theory of ageing is based on oxidative stress as well. There exist endogenous and exogenous antioxidants capable of fighting oxidative and nitrosative damage to molecules and tissues of the body. Such compounds may be beneficial in prevention and treatment of different conditions. For example, plant foods contain various amounts of antioxidants. The aim of this thesis is to evaluate the antioxidant-related activities of certain commonly used vegetables (broccoli, brussel sprouts, cauliflower, peas), berries (bilberry, raspberry), herbs (Egyptian basil, oregano, rosemary, thyme) and spices (paprika) and to discuss their role in human health. The sample extracts were tested with four different methods: the determination of total phenols using Folin-Ciocalteu reagent, the DPPH free radical scavenging activity assay, reducing power activity assay and iron (II) chelation. In all assays, with exception of iron (II) chelation, vegetables proved to be less active as a potential source of antioxidants than other samples, while herbs seemed to be the most active samples. Iron chelation potential of samples is approximately the same with exception of paprika (lower than other samples) and bilberry (higher than other samples). The results obtained from different assays are not consistent with each other, and good correlative relationship occurs only between total phenols and iron reduction. On the basis of the results, it can be assumed that herbs and berries may be the main target for the research of pharmaceutically important antioxidants, although in daily diet vegetables and fruits are likely to be the best sources of such compounds. However, the beneficial daily doses of plant foods remain to be considered and further research is needed to provide information on the activity of given samples in vivo.
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(2019)Chicory (Cichorium intybus) is a biennial or perennial plant belonging to Asteraceae family grown worldwide for its roots, but also for its leaves. Chicory has been utilized as a food crop, but also because of its medicinal properties, for at least two millennia. The aim of the Master's thesis was to produce hair root and cell cultures from chicory, and to evaluate the antimicrobial and antioxidant properties of extracts made from them. Hair root infection is caused by the soil-borne bacterium Agrobacterium rhizogenes, which transfers its own DNA into the genome of the plant and causes the plant to produce opines which the bacteria uses as a nutrient source. Hairy root infection causes the plants to grow excessive amount of lateral roots and at the same time increases the formation of secondary metabolites. Hairy roots can be grown on a solid or liquid medium without added plant hormones, and this phenomenon is utilized in a number of biotechnological applications. The successful initiation of hair roots requires suitable conditions and components, but once these are clear the process itself is quite simple. Wounded explants are infected with either a liquid bacterial suspension or by direct transfer of bacterial growth. After infection bacterial growth is eliminated with the use of antibiotics. Hairy roots are initially identified by morphological traits and verified by detecting rol genes with the use of PRC. Plant cell suspension cultures are produced from explants with the help of auxin and cytokinin in suitable proportions. As with hairy root cultures, plant cell suspension cultures can be harnessed to produce various molecules of economic benefit. Bioactivity of plant extracts can be studied by a variety of different methods. DPPH and antimicrobial assays were used to investigate the bioactivity of hairy root and cell suspension cultures produced for the study. The DPPH assay is used to measure radical scavenging properties of samples, by comparing the results to a reference antioxidant such as for example Trolox, which is a synthetic vitamin-E. Methanol extracts of hairy roots, cell suspension cultures, and natural roots were assayed for their antioxidant properties with the DPPH assay. Hot water extracts of hairy root and cell suspension cultures were tested against VTT-E70045 Staphylococcus aureus strain for antimicrobial properties. The results of the study showed that especially the antioxidant properties of chicory hair roots differ greatly from natural roots and cell suspension cultures. The radical scavenging properties of hairy root extracts were up to 45 times more potent than of extracts made from natural root and cell suspension cultures. The results of the antimicrobial experiment showed that all extracts from hair root and cell suspension cultures had bacteriostatic properties. One hairy root clone 2R5 clearly had antimicrobial effects, and it would be interesting to do a more thorough assessment to find out which compounds are responsible for this.
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(2021)Oat has a high content of lipids compared to many other grains. Oat contains lipid hydrolysing enzyme, lipase, and unsaturated fatty acids, which are prone to oxidation. Hydrolytic reactions and oxidation of lipids may cause major quality changes in oats. Oat contains also phenolic antioxidants - tocols, avenanthramides and phenolic acids - that may inhibit lipid oxidation. The aim of this research was to examine how tocols, avenanthramides and phenolic acids act as antioxidants in oat during lipid oxidation. The purpose was to study concentration changes of these compounds in six oat samples in storage. The storage experiment was performed for 12 weeks at 40 °C. Tocols, avenanthramides, phenolic acids and neutral lipids were analysed by liquid chromatography methods after 0, 2, 4, 8 and 12 weeks of storage. Volatile compounds were measured by a solid phase microextraction gas chromatography method. During the storage, volatile compounds, such as hexanal and 2-pentylfuran, were formed especially in groats. Free fatty acids were hydrolysed from triacylglycerols only in groats, because lipase was active in these samples. The α-tocol concentrations of oat samples decreased significantly, 45-77%, in storage. The β-tocotrienol concentrations decreased 34-53%. At the beginning of the storage avenanthramide concentrations showed 20-45% reduction. After that, the concentrations were either stable or increased 10-30%. The phenolic acid concentrations either decreased, increased or were stable during storage. The most significant change was found in unheated groats where the concentration of free caffeic acid increased even 2.6-fold during eight weeks of storage. The loss of α-tocols imply that these compounds are effective antioxidants in oat. This study did not indicate antioxidant activity of avenanthramides and phenolic acids in oat because the changes of these compounds varied in storage. However, the variation of avenanthramide and phenolic acid concentrations may have been caused by their antioxidant activity and release of bound compounds. Thus, further research is needed in order to study the effect of avenanthramides and phenolic acids in oat during lipid oxidation.
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(2018)The main objective of the literature review of this Master’s Thesis was to gather information concerning cosmetic products, especially plant based cosmetic ingredients and how they are produced. The part consists of information about cosmetic legislation, safety of cosmetic products and introduction of plant sample materials used in the experimental part. The aim of this Master’s thesis was to isolate plant extracts containing phenolics from three different plant materials (cowberry [Vaccinium vitis-idaea], birch leaf [Betula pendula/pubescens] and flax seed [Linum usitatissimum]) by using accelerated solvent extraction (ASE) with two different extraction solvents (94 % ethanol and 80 % acetone), and supercritical fluid extraction (SFE). The content of total phenolics in the extracts was determined spectrometrically according to the Folin−Ciocalteau procedure and calculated as gallic acid equivalents (GAE). Chlorophyll and carotenoid content of birch leaf extracts were also determined. Antioxidant activity of extracts was tested with emulsion test, where rapeseed oil containing emulsion was oxidized in the presence of plant extracts. Oxidation of the emulsion was monitored for 7 days by determining the content of hydroperoxides in emulsion with a spectrophotometric method. Amount of plant extracts added to emulsions was 100 or 500 μg GAE phenolics per g of oil in emulsion. ASE was suitable for extracting phenolics from all the sample materials. Cowberry and birch leaf extracts contained remarkable amounts of phenolic compounds, but flax seed extracts contained only small amounts of those. Phenolics in flax seed are mainly lignans, which are tightly bound to the hull part of the seed. Thus, it requires extensive pretreatments to extract them. SFE was not suitable method for extracting phenolics from any of the sample materials. Inhibition of oxidation varied between different extracts. Cowberry extract containing 500 μg GAE per g of oil was the most effective extract in inhibiting oxidation in emulsion. Birch leaf extracts inhibited oxidation until day 4. After that the amount of hydroperoxides increased relatively fast. Birch leaf extracts were rich in chlorophylls, which can act as a pro-oxidants. According to the results, cowberry was most optimal raw material of the tested materials for isolating antioxidant containing extracts from plant materials. Both acetone and ethanol were suitable extraction solvents for ASE.
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(University of HelsinkiHelsingin yliopistoHelsingfors universitet, 2009)Oksidatiivinen stressi on tila, jossa elimistön vapaiden radikaalien ja antioksidanttien suhde on epätasapainossa. Tämä voi johtua joko vapaiden radikaalien ylimäärästä tai antioksidanttien puutteesta. Vapailla radikaaleilla tarkoitetaan aineenvaihdunnassa muodostuvia hapen ja typen lajeja, jotka ovat herkästi uudelleen reagoivia. Antioksidantit ovat aineita, jotka viivyttävät, estävät tai poistavat vapaiden radikaalien aiheuttamia vaurioita. Eläinlääketieteessä tiedetään melko vähän oksidatiivisen stressin vaikutuksesta eläinten terveyteen ja hyvinvointiin. Tämän kirjallisuuskatsauksen tarkoituksena oli selvittää mitä antioksidantit ovat, ja mitkä ovat niiden vaikutusmekanismit. Työssä koottiin yhteen kotieläinten ravitsemuksessa eniten tutkittujen antioksidanttien terveys- ja laatuvaikutuksia. Lisäksi työssä selvitettiin antioksidanttien ja oksidatiivisen stressin tutkimusmenetelmiä lypsylehmillä ja lihasioilla. Tavoitteena oli arvioida uusimmissa antioksidanttitutkimuksissa käytettyjen merkkiaineiden, määritysmenetelmien ja koeasetelmien soveltuvuutta tuotantoeläimille. Oksidatiiviset vauriot kohdistuvat solussa rasvoihin, valkuaisaineisiin tai nukleiinihappoihin. Endogeenisiä antioksidantteja ovat katalaasi, superoksididismutaasi, sekä glutationi- ja tioreduksinjärjestelmään kuuluvat entsyymit. Ravinnosta saataviin antioksidantteihin kuuluvat E- ja C-vitamiini, A-vitamiinin esiasteena tunnettu β-karoteeni, sekä hivenaineet seleeni, kupari ja sinkki. E-vitamiini ja karotenoidit ovat rasvaliukoisia aineita, jotka suojaavat rasvojen hapettumiselta. C-vitamiini ja glutationi ovat vesiliukoisia aineita, jotka voivat suojata rasvojen, valkuaisaineiden ja nukleiinihappojen hapettumiselta. Antioksidantit toimivat yhteistyössä. Hivenaineet toimivat solunsisäisten antioksidanttisten entsyymien, kuten superoksidismutaasin ja glutationiperoksidaasin osana. Antioksidanttit toimivat yhteistyössä. E-vitamiinilla ja seleenillä on vaikutusta lypsylehmällä poikimisen tienoilla esiintyvien sairauksien, kuten utaretulehduksen, jälkeisten jäämisen ja kohtutulehdusten esiintyvyyteen. Antioksidantteja on tutkittu myös hedelmällisyyteen liittyvien fysiologisten toimintojen yhteydessä. Antioksidanteilla on vaikutuksia lihanlaatuun märehtijöillä ja sioilla. E-vitamiini- ja seleeninlisä vaikuttaa rasvojen härskiintymiseen, lihan väriin, vedensidontakykyyn, rasvahappokoostumukseen ja antioksidanttipitoisuuteen. Karotenoideilla on vaikutusta rasvakudoksen väriin. Antioksidanteilla on vaikutusta myös maidon rasvapitoisuuteen, rasvahappokoostumukseen ja maidon sisältämien antioksidanttien määrään. Antioksidanttien toimintaa voidaan määrittää mittaamalla suorasti tai epäsuorasti antioksidanttien määrää tai antioksidanttien puutteesta syntyneitä oksidatiivisia vaurioita. Antioksidanttien määrää voidaan mitata joko arvioimalla antioksidanttien kokonaiskapasiteettia tai mittaamalla yksittäisten antioksidanttien määrää nestekromatokrafialla. Nukleiinihappoihin kohdistuvia vaurioita voidaan mitata COMET-analyysillä. Aminohappojen hapettumista voidaan mitata arvioimalla kolorimetrillä karbonyyliryhmien määrää. Rasvojen hapettumista voidaan määrittää mittaamalla malondialdehydin tai isoprostaanien määrää. Tuotantoeläimiltä verestä ja lihaksesta määritettyjä merkkiaineita ovat esimerkiksi malondialdehydi, glutationi ja muut yksittäiset antioksidantit. Lypsylehmillä oksidatiivisen stressin ja antioksidanttien tutkimisessa eri merkkiaineiden ja määritysmenetelmien käyttö on vielä vakiintumatonta. Lihasioilla tehdyissä lihanlaatukokeissa tiobarbituraattihappoon perustuva malondialdehydin määritys on eniten käytetty menetelmä rasvojen hapettumisen mittaamiseen. Antioksidanttien tutkimusmenetelmäksi sopivat kliiniset koe-eläinkokeet, joissa koeasetelmana käytetään faktorikoetta.
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(University of HelsinkiHelsingin yliopistoHelsingfors universitet, 1994)Kokeen tarkoituksena oli seleeni- ja E-vitamiiniköyhän dieetin avulla, johon lisättiin härskiä kalanmaksaöljyä, saada porsaille aikaan oksidatiivinen stressi. Tällaisen dieetin tiedetään aiheuttavan nutritionaalista lihasrappeumaa (NMD), maksarappeumaa (HD) ja ns. mulberry heart diseasen (MHD). Stressiä lisättiin rauta-injektion avulla, sillä rauta nopeuttaa lipidien peroksidaatiota eli rasvojen härskiintymistä. Veriparametrien, makroskooppisten, valomikroskooppisten sekäelektronimikroskooppisten tutkimusten avulla selvitettiin oksidatiivisen stressin aikaansaamia vaurioita stressille herkissä kohde-elimissä, kuten sydämessä, maksassa ja luustolihaksissa. Vauriot olivat selvästi todettavissa mm. tietyissä veriparametreissä (Fe, TBARS, CK, TIBC) rauta-injektion saaneilla porsailla, ilmentäen merkittävää raudan yliannostusta ja siitä seuraavaa solukalvojen vaurioitumista.
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(2016)Protected cultivation of raspberries (Rubus idaeus L.) has increased its popularity in Finland. One reason is that the fruit is extremely sensitive to rainy weather during its development. The raspberry plant itself is sensitive to wind and low temperatures, which can reduce growth. In Europe most of the raspberry is grown in protected cultivation, and this technology is now becoming popular in Finland. A high tunnel is a cost-efficient way to protect the plants against rainy weather and extend the harvest season. The protected cultivation has been shown to increase the yield and cropping potential of raspberry and reduce the gray mold in the berries. In human diet, berries are among the richest sources of antioxidants. In raspberry, the most important antioxidants are vitamin C (20 %) and phenolic compounds (80 %). Among phenolic compounds, ellagitannins and anthocyanins give the greatest contribution to antioxidant activity. The aim of this thesis was to study the yield, sensory quality, nutritional quality and shelf life of three floricane fruiting raspberry cultivars grown in high tunnel and open field. Cultivars ’Glen Ample, ’Glen Dee’ and ’Maurin Makea’ were used in the study. Sugar and acid content of raspberry were examined to get an overview of sensory quality. The nutritional quality was studied with an antioxidant activity assay (using FRAP method) and total phenolics assay (using Fast Blue BB method). The shelf life was tested both in +5 °C and in room temperature. The average total yield per cane was 99 % greater in tunnel than in the open field, whereas both sugar and acid content of the berry were greater in open field. Berry weight and total phenolics content were strongly cultivar dependent characteristics. The results of the antioxidant activity assay did not show significant differences between either growing conditions or the cultivars. The shelf life in room temperature was equally weak for all samples, but in +5 °C storage the open field raspberries developed symptoms of gray mold earlier than those picked from the tunnel. The conclusion is that contents of health beneficial compounds in berries were not affected in tunnel cultivation, but berry taste may be affected, as differences in sugar and acid contents were observed.
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(2016)Protected cultivation of raspberries (Rubus idaeus L.) has increased its popularity in Finland. One reason is that the fruit is extremely sensitive to rainy weather during its development. The raspberry plant itself is sensitive to wind and low temperatures, which can reduce growth. In Europe most of the raspberry is grown in protected cultivation, and this technology is now becoming popular in Finland. A high tunnel is a cost-efficient way to protect the plants against rainy weather and extend the harvest season. The protected cultivation has been shown to increase the yield and cropping potential of raspberry and reduce the gray mold in the berries. In human diet, berries are among the richest sources of antioxidants. In raspberry, the most important antioxidants are vitamin C (20 %) and phenolic compounds (80 %). Among phenolic compounds, ellagitannins and anthocyanins give the greatest contribution to antioxidant activity. The aim of this thesis was to study the yield, sensory quality, nutritional quality and shelf life of three floricane fruiting raspberry cultivars grown in high tunnel and open field. Cultivars ’Glen Ample, ’Glen Dee’ and ’Maurin Makea’ were used in the study. Sugar and acid content of raspberry were examined to get an overview of sensory quality. The nutritional quality was studied with an antioxidant activity assay (using FRAP method) and total phenolics assay (using Fast Blue BB method). The shelf life was tested both in +5 °C and in room temperature. The average total yield per cane was 99 % greater in tunnel than in the open field, whereas both sugar and acid content of the berry were greater in open field. Berry weight and total phenolics content were strongly cultivar dependent characteristics. The results of the antioxidant activity assay did not show significant differences between either growing conditions or the cultivars. The shelf life in room temperature was equally weak for all samples, but in +5 °C storage the open field raspberries developed symptoms of gray mold earlier than those picked from the tunnel. The conclusion is that contents of health beneficial compounds in berries were not affected in tunnel cultivation, but berry taste may be affected, as differences in sugar and acid contents were observed.
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(University of HelsinkiHelsingin yliopistoHelsingfors universitet, 1990)Tämä syventävien opintojen tutkielma sisältää kirjallisuuskatsauksen ja tutkimusosan. Kirjallisuuskatsauksessa käsitellään eri antioksidantteja ja rasvahappoja. Tutkimusosassa on mitattu kolmentoista lämminverisen ravurin veren A- ja E-vitamiinipitoisuudet, Fe-, Zn-, Se- ja Mn-pitoisuudet sekä plasman rasvahappopitoisuudet. Tarkoituksena oli alustavasti määrittää eri antioksidanttien ja rasvahappojen pitoisuuksia hevosella.
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