Browsing by Subject "storage"

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  • Ottka, Claudia; Vapalahti, Katariina; Puurunen, Jenni; Vahtera, Laura; Lohi, Hannes (2021)
    Background Metabolomics has been proven to be an invaluable research tool by providing comprehensive insight into systemic metabolism. However, the lack of scalable and quantitative methods with known reference intervals (RIs) and documented reproducibility has prevented the use of metabolomics in the clinical setting. Objective The objective of this study was to validate the developed quantitative nuclear magnetic resonance (NMR) spectroscopy-based metabolomics platform for canine serum and plasma samples and determine optimal sample handling conditions for its use. Methods Altogether, 8247 canine samples were analyzed using a Bruker's 500 MHz NMR spectrometer. Using statistical approaches derived from international guidelines, we studied method precision, measurand stability in various long- and short-term storage conditions, as well as the effect of prolonged contact with red blood cells (RBCs), and differences among blood collection tubes. We also screened interferences with lipemia, hemolysis, and bilirubinemia. The results were compared against routine clinical chemistry methods, and RIs were defined for all measurands. Results We determined RIs for 123 measurands, most of which were previously unpublished. The reproducibility of the results of the NMR platform appeared generally outstanding, and the integrity of the results can be ensured by following standard blood drawing and processing guidelines. Conclusions Owing to the advantages of quantitative results, high reproducibility, and scalability, this canine metabolomics platform holds great potential for numerous clinical and research applications to improve canine health and well-being.
  • Martínez Meyer, Marcela Raquel (Helsingfors universitet, 2010)
    Protein-energy malnutrition and mineral deficiencies are two of the three forms of nutritional deficiencies that affect most developing countries due to inadequate access to food and diets based on a sole crop. Common bean (Phaseolus vulgaris L.) is the staple crop of Nicaragua and it has the potential to improve the nutritional status of the poorest group of the nation. Its high content of both protein and nonhaem iron provides many nutrients, but inhibitors also may prevent absorption of iron and zinc by the human consumer. A proper production chain must be followed to ensure the best grain quality for the consumer. To achieve food security, both production and high nutritional content must be maintained. Four nationally important accessions of common bean, with different harvesting dates, were selected to be submitted to two treatments: to evaluate the impact of storage conditions on the end quality of the grain. The duration of the study was six months with sampling every six weeks, and the two treatments were controlled one stored at 40°C and 75 RH %, and the other was stored in in-situ conditions. Proximate and mineral composition was evaluated as well as tannin, phytate and bioavailability. Significant differences among different accessions were found, being the most significant in protein, Fe and Zn content, tannins and phytate. Protein values ranged from 21-23%. Iron content was 61-81 mg/kg but only 3-4% was bioavailable. Zinc content was 21-25 mg/kg and 10-12% was bioavailable. The concentration of phytate ranged from 8.6-9.6 mg/g while tannin values ranged within 37.7-43.8 mg/g. Storage at high temperatures was demonstrated to have an impact on certain nutritional compounds and proved detrimental to final grain quality. Soluble sugar content and tannin content decreased after six months in both storage conditions, IDF decreased in the in-situ and SDF in the stress. The iron content and bioavailability in INTA Biofortificado were not as outstanding as expected, so experiments should be conducted to compare its iron uptake and delivery with other cultivars.
  • Merivirta, Lauri; Björkroth, Johanna; Korkeala, Hannu (International Association for Food Protection, 2003)
    The microbiological quality of 30 production lots of charcoal broiled river lampreys was studied at three lampreys processing plants (A, B and C). Samples were taken directly after charcoal broiling and stored at 22°C and at 3°C. Lampreys were examined on the day of manufacturing and those kept at 22ºC every second day for 6 days. Samples kept at 3ºC were examined every fourth day up to 24 days. On the production day the mean aerobic plate counts (APC) in broiled lampreys were 2.29 log CFU/g, 1.88 log and ND (1.67 log) in plant A, B and C, respectively. At 22C the mean APCs of samples from plant A, B and C increased markedly within 4 days, and after 6 days were 8.56 log, 5.04 log and 6.23 log CFU/g, respectively. The chilling and storing at 3C remarkably improved the self-life of the product. The numbers of bacteria in charcoal broiled river lampreys from plant A were higher than those from plant B and C. No significant increase in APCs was observed during storage at 3C for 24 days; the mean APC did not exceed the number 2.80 log CFU/g in samples from any plant. Staphylococcus aureus was observed in two samples. No lactic acid bacteria, thermotolerant coliforms, enterococci, Clostridium perfringens or Listeria monocytogenes were detected. Microbiological data from this study will be used for the development of a hazard analysis for determining the critical control points.
  • Nykänen, Heli (Helsingfors universitet, 2009)
    Greenhouse cucumber (Cucumis sativus) is one of the most important vegetables in Finland with annual consumption of about 30 million kilogrammes. The cucumber itself generates ethylene at a low level, but excessive ethylene concentrations (>0.5 ppm) in ambient air causes quality losses, like yellowing and softening. The problem is that cucumbers often share the same airspace with ethylene generating fruits and vegetables during transport, storage and sale. The literature review deals with ethylene synthesis and its effects in vegetables. Also, ethylene measurements and detection, as well as ethylene exhaustion, and inhibition are discussed. The aim of the experimental study was to find the best available packaging material for greenhouse cucumbers. From 13 different packaging alternatives, studied in a preliminary test, the most promising were selected for storage experiments. Cucumbers were cultivated in greenhouses in SouthWest Finland. Packed cucumbers were stored at 12 ºC and in airflow with 1 ppm ethylene for 14 or 7 days for the first and second trial, respectively. Analyses were performed once a week. They consisted of O2and CO2concentrations of packages and sensory quality of whole and sliced cucumbers. Cucumbers were also photographed. Results showed that cucumbers packed in low oxygen transmission film deteriorated fast, whereas too many holes in a package resulted in high weight losses. Cucumbers packed in shrinkwrapped PEpackages with micro holes had lighter green colour than other cucumbers after 13 days. Cucumbers packed in biodegradable film had nearly 25 % weight loss after 27 days compared to other packages causing weight loss of 3 %. After 13 and 21 days’ storage time the freshness of taste was better if the PPpouch with an ethylene scavenger was used. The currentlyused shrinkwrapped PEpackage with micro holes proved to be a good choice for cucumbers if there is no risk of ethylene in food chain. If ethylene is present, it is better to use a PPpouch with micro holes. In that case, additional benefit of improved freshness of taste can be achieved by using ethylene scavengers.
  • Laamanen, Tuija-Liina (Helsingfors universitet, 2015)
    Carrot production is very specialized and professional in Finland. Long term storage of the yield is necessary during winter. In storage, the resistance of carrots to diseases decreases even with optimized storage conditions. Diseases can cause huge losses during long storage periods, but the severity of losses varies between years and fields. One of the most harmful diseases of carrots during storage is Mycocentrospora acerina. It is a soil borne fungus that cannot be controlled by fungicides. This is a study of the test method to evaluate the risk of M. acerina in a field. In this test slices of carrots were placed in a container with collected soil samples from a test field. The containers with soil samples and carrot slices were kept six weeks in the dark at +15 °C temperature. After that it was possible to see if M. acerina had grown up from the soil and infected the carrots by forming dark colored patches to the carrot slices. By calculating and comparing the amount of patches on each soil sample it was possible to evaluate the risk of M. acerina in a test field. Results from the test were compared to amount of M. acerina infection found in stored carrots harvested from the same fields. The study showed that it is possible to evaluate the risk of M. acerina. Soil samples can be collected in different times of the year, and the test can be made with fresh or storage carrots. The test samples need to be comparable, so they must be collected the same way and the amount of samples in each container must be sufficient to minimize variation. This study will introduce simple guidelines that farmers can use to test fields and evaluate the risk of M. acerina.
  • Yrjölä, Heikki (Helsingfors universitet, 2009)
    Ilmastonmuutos, fossiilisten polttoaineiden väheneminen sekä niiden hinnan nousu ovat aiheuttaneet sen, että kiinnostus uusiutuvia energiavaroja kohtaan on kasvanut huomattavasti viime vuosien aikana. Peltobioenergian käyttö on ollut vähäistä Suomessa mutta sen käyttö on yleistymässä. Bioenergiakasveista ruokohelven viljely on lisääntynyt Suomessa merkittävästi, koska se on satoisin energiakäyttöön tarkoitetuista heinäkasveista. Ruokohelven pääasiallinen käyttötarkoitus on polttaminen voimalaitoksissa silputtuna ja sekoitettuna pääpolttoaineeseen eli esimerkiksi turpeeseen tai hakkeeseen. Jotta ruokohelven lämpöarvo tai muut ominaisuudet eivät heikentyisi, niin varastointi tulisi suorittaa oikein. Tutkimuksen tavoitteena oli selvittää optimaalisin varastointimuoto ruokohelpipaaleille. Työ aloitettiin perustamalla erilaisia koevarastoja pyörö- ja suurkanttipaaleille. Koevarastoinnin tarkoituksena oli kokeilla erilaisten kate- pohjamateriaalien sekä niiden yhdistelmien vaikutusta paalien kosteuspitoisuuksiin viiden kuukauden aikana sekä laskea varastointikustannukset eri varastotyypeille. Tutkimuksessa mukana olleet katemateriaalit olivat aumamuovi, kevytpeite, peitepaperi sekä peittämätön versio. Pohjamateriaaleina tutkimuksessa käytettiin aumamuovia, trukkilavoja sekä paljasta maata. Tavoitteena oli myös selvittää kolmen erilaisen kannettavan pikakosteusmittarin tarkkuus verrattuna uunikosteuteen. Vertailussa mukana olleet mittarit olivat: Wile 25 Digital, Haymatic Digital ja DICKEY-john. Katemateriaaleista parhaaksi ratkaisuksi osoittautui aumamuovi. Se ei päästänyt vettä lävitseen eikä myöskään kondensoitumista havaittu tutkimuksen aikana. Kustannuksia tarkasteltaessa aumamuovi oli ylivoimaisesti edullisin vaihtoehto vertailluista vaihtoehdoista. Pohjamateriaaleista trukkilavat olivat paras vaihtoehto ruokohelpipaalien varastointiin. Aumamuovi sekä paljas maa keräsivät vettä ja kastelivat paaleja alaosastaan. Mittarivertailussa tarkimmaksi kannettavaksi pikakosteusmittariksi osoittautui Wile 25 Digital paalien kosteuden ollessa alle 20 %. Mittarin tarkkuus ei kuitenkaan ollut riittävä tarkkojen mittausten suorittamiseen. Kestoltaan alle viiden kuukauden varastointiaikoina lappeelleen varastoituja pyöröpaalivarastoja ei ole taloudellisesti järkevää peittää eikä niiden alle tarvitse asettaa pohjamateriaalia. Sen sijaan suurkanttipaalivarastot tulisi peittää myös lyhytaikaisen varastoinnin aikana, koska suurkanttipaalit ovat huomattavasti herkempiä kastumaan kuin lappeelleen varastoidut pyöröpaalit. Varastointiajan ollessa yli viisi kuukautta molemmat varastotyypit tulisi peittää aumamuovilla sekä pohjustaa varastot trukkilavoilla tai muulla sellaisella materiaalilla joka pitää alimmat paalit pois märästä maasta.
  • Ilvonen, Petra (Helsingin yliopisto, 2020)
    Extracellular vesicles (EVs) are a very heterogeneous group of cell originated nanoparticles that act as mediators of intercellular communication. Accurate characterization of EVs is essential to enable their wider use and development as possible biomarkers, drug carriers, and vaccines. There is no validated reference material with EV-like properties currently available. A validated reference material would improve the reliability and reproducibility of EV studies. Nanoerythrosomes (NanoE) have been studied as a possible option for biological reference material. We aimed to further characterize and compare properties of NanoEs and erythrocyte-derived EVs (EryEV) and assess their stability concerning concentration and size distribution at most commonly applied storage temperatures, +4°C, -20°C, and -80°C for 12 weeks. Characterization was done using nanoparticle tracking analysis and flow cytometry. In addition, we studied the surface protein expression including CD235a, CD47, and CD41 of NanoEs and EryEV and conducted a preliminary cellular uptake test using PC-3 cells, CFSE-labeled NanoE, and EryEV particles. For both, NanoE and EryEV samples, 20°C was the worst storage condition. NanoEs stay stable at +4°C for a month and at -80°C, there were some drops in concentration during the 12 weeks of the experiment. EryEVs stay stable at +4°C and -80°C for 12 weeks. Both NanoE and EryEV particles seemed to be taken into the PC-3 cells, but due to problems with autofluorescence we conclude that confirming studies with different labeling protocols or another method need to be conducted. Both NanoEs and EryEVs samples had a significant number of CD47-positive particles.
  • Kamppari, Kirsi (Helsingin yliopisto, 2019)
    Meat is a nutrient dense food providing us valuable amounts of fatty acids, minerals and vitamins and it is involved in the synthesis of protein, fat and membranes in the human body. Pork and poultry consumption has increased since 1970’s in Finland. Meat quality traits are affected by several factors such as breed, genotype, sex, rearing conditions, the animal’s age at the time of the slaughter and nutrition to mention few. The current study is part of INNOFEED-project which aims to show how and why ensiled grass should be biorefined into a variety of inventive feed products and that way establish new type of biorefineries from our most abundant field grown biomass. Grass silage can be pressed, and that way produce juice. The aim of the present study was to evaluate the influence of grass silage juice on fatty acid composition and vitamin E content on pork meat and whether it has an effect on lipid oxidation or color in vacuum and MAP packaged pork meat. Grass silage juice did not influence on total fat content or fatty acid composition in pork longissimus thoracis muscle. In vacuum packaged meat, there were no difference between feeding groups when oxidation was measured with TBARS. In MAP packed meat test feed group gave higher TBARS results throughout the storage period. Grass silage juice effected on color, especially on L* and a*-values. Meat color from test feed group was lighter and not as red as meat from control feed group.
  • Ryynänen, Martti (Suomen metsätieteellinen seura, 1980)