Browsing by Subject "elintarviketurvallisuus"

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  • Gürbüz, Göker (Helsingfors universitet, 2010)
    The literature review elucidates the mechanism of oxidation in proteins and amino acids and gives an overview of the detection and analysis of protein oxidation products as well as information about ?-lactoglobulin and studies carried out on modifications of this protein under certain conditions. The experimental research included the fractionation of the tryptic peptides of ?-lactoglobulin using preparative-HPLC-MS and monitoring the oxidation process of these peptides via reverse phase-HPLC-UV. Peptides chosen to be oxidized were selected with respect to their amino acid content which were susceptible to oxidation and fractionated according to their m/z values. These peptides were: IPAVFK (m/z 674), ALPMHIR (m/z 838), LIVTQTMK (m/z 934) and VLVLDTDYK (m/z 1066). Even though it was not possible to solely isolate the target peptides due to co-elution of various fractions, the percentages of target peptides in the samples were satisfactory to carry out the oxidation procedure. IPAVFK and VLVLDTDYK fractions were found to yield the oxidation products reviewed in literature, however, unoxidized peptides were still present in high amounts after 21 days of oxidation. The UV data at 260 and 280 nm enabled to monitor both the main peptides and the oxidation products due to the absorbance of aromatic side-chains these peptides possess. ALPMHIR and LIVTQTMK fractions were oxidatively consumed rapidly and oxidation products of these peptides were observed even on day 0. High rates of depletion of these peptides were acredited to the presence of His (H) and sulfur-containing side-chains of Met (M). In conclusion, selected peptides hold the potential to be utilized as marker peptides in ?-lactoglobulin oxidation.
  • Tuomisto, Pirkko (Evira, 2009)
    4/2008
    The drive for risk-based food safety management, systems and control has spread world-wide in recent decades. Since the term is still internationally undefined, its use and implementation vary, producing different realizations. In this Ph.D. thesis, microbiological risk assessment (MRA) was investigated as a basis for risk-based food safety management, which was defined as ‘food safety management based on risk assessment in order to achieve an appropriate level of protection (ALOP)’. Governments are responsible for commissioning MRAs and also for setting food safety targets up to a certain point, but the practical management measures that need to be in place in order to achieve the targets are to be addressed by the operators. On the plant level, food safety is usually managed through regulation, quality assurance systems and a hazard analysis and critical control point (HACCP) programme with its prerequisites. In Finland, food safety management on the food plant level is implemented through an HACCP-like regulated system termed an ownchecking (OC) programme. A quantitative microbiological risk assessment (QMRA) was conducted on salmonella in the beef production chain according to the official standards of the Codex Alimentarius Commission (Codex Alimentarius), and utilized in determining the food safety metrics for beef production. The Finnish Salmonella Control Programme (FSCP) and the main official interventions due to it were examined in the light of risk-based food safety management. The targets set for beef processing plants by the government were converted into quantitative limits, and the results of salmonella monitoring included in the FSCP were examined by the QMRA. The goal of the FSCP was declared in 1994 to ‘maintain the present salmonella situation’, which was considered to refer to the salmonella incidence in humans at that time, and also the de facto ALOP. The requirement for a maximum salmonella prevalence of 1% at defined stages of the beef production chain was embodied in the FSCP. This statement was considered to convey performance objectives (PO) for the aforementioned stages. According to the QMRA, the de facto ALOP was achieved in the referred year 1999, and even the true prevalence levels in the FSCP were estimated to be clearly under the set PO limits with 95% credibility. However, the PO limits were set too high for the de facto ALOP to be maintained in practice. If the salmonella prevalence reached the PO limit of 1% or values near it, the public health risk would increase and overrun the de facto ALOP. The QMRA produced in this work has for the first time provided the possibility to quantitatively asses the relationships between targets set in the FSCP and their impact on public health. At present, imports of beef and beef-derived foods may impose on Finnish consumers a significantly greater exposure than domestic products. If their salmonella prevalence or their share of the foods consumed in Finland increase, the number of human cases could rapidly rise. The models for the QMRA were mainly Bayesian hierarchical models using Markov chain Monte Carlo (MCMC) techniques, which was found to be a flexible and appropriate method for this type of complex modelling. The resulting distributions were also regarded as an advantage compared to the results from models developed with the deterministic approach, because the presentation of results included the extent of the uncertainty, and also in this manner better illustrated the actual operational environment. Based on an inquiry, the personnel in food processing plants had a positive attitude towards food safety management systems, but the knowledge, training and involvement of those employees directly operating on the site with these systems were discovered to be deficient. Therefore, a generic semi-quantitative hygiene risk assessment model, Hygram®, was developed for small and medium-sized food enterprises to offer assistance in understanding, training, and, first of all, detecting the critical steps of the processes, and thereby to contribute to the development of their own-checking systems towards risk-based food safety management. Hygram® was not considered a risk-based tool as such, but whenever the critical limits of the process have been defined as equal to a risk assessment, Hygram® can be used as a risk-based management tool. It can also serve as a tool for systematic hazard analysis and CCP detection when establishing a food safety management system. To conclude, the development of risk-based food safety management is a process in which risk assessment is an essential tool. Scientific, technical, psychological and resource-bound barriers need to be overcome in order to put risk-based management systems into practice. This study showed that QMRA can be valuable in national risk management decision making, although few QMRAs are currently available. Appropriate tools for practical risk management decision making on the industrial level, such as Hygram®, need to be further developed.
  • Tuominen, Pirkko (Evira, 2008)
    4/2008
    The drive for risk-based food safety management, systems and control has spread world-wide in recent decades. Since the term is still internationally undefined, its use and implementation vary, producing different realizations. In this Ph.D. thesis, microbiological risk assessment (MRA) was investigated as a basis for risk-based food safety management, which was defined as ‘food safety management based on risk assessment in order to achieve an appropriate level of protection (ALOP)’. Governments are responsible for commissioning MRAs and also for setting food safety targets up to a certain point, but the practical management measures that need to be in place in order to achieve the targets are to be addressed by the operators. On the plant level, food safety is usually managed through regulation, quality assurance systems and a hazard analysis and critical control point (HACCP) programme with its prerequisites. In Finland, food safety management on the food plant level is implemented through an HACCP-like regulated system termed an ownchecking (OC) programme. A quantitative microbiological risk assessment (QMRA) was conducted on salmonella in the beef production chain according to the official standards of the Codex Alimentarius Commission (Codex Alimentarius), and utilized in determining the food safety metrics for beef production. The Finnish Salmonella Control Programme (FSCP) and the main official interventions due to it were examined in the light of risk-based food safety management. The targets set for beef processing plants by the government were converted into quantitative limits, and the results of salmonella monitoring included in the FSCP were examined by the QMRA. The goal of the FSCP was declared in 1994 to ‘maintain the present salmonella situation’, which was considered to refer to the salmonella incidence in humans at that time, and also the de facto ALOP. The requirement for a maximum salmonella prevalence of 1% at defined stages of the beef production chain was embodied in the FSCP. This statement was considered to convey performance objectives (PO) for the aforementioned stages. According to the QMRA, the de facto ALOP was achieved in the referred year 1999, and even the true prevalence levels in the FSCP were estimated to be clearly under the set PO limits with 95% credibility. However, the PO limits were set too high for the de facto ALOP to be maintained in practice. If the salmonella prevalence reached the PO limit of 1% or values near it, the public health risk would increase and overrun the de facto ALOP. The QMRA produced in this work has for the first time provided the possibility to quantitatively asses the relationships between targets set in the FSCP and their impact on public health. At present, imports of beef and beef-derived foods may impose on Finnish consumers a significantly greater exposure than domestic products. If their salmonella prevalence or their share of the foods consumed in Finland increase, the number of human cases could rapidly rise. The models for the QMRA were mainly Bayesian hierarchical models using Markov chain Monte Carlo (MCMC) techniques, which was found to be a flexible and appropriate method for this type of complex modelling. The resulting distributions were also regarded as an advantage compared to the results from models developed with the deterministic approach, because the presentation of results included the extent of the uncertainty, and also in this manner better illustrated the actual operational environment. Based on an inquiry, the personnel in food processing plants had a positive attitude towards food safety management systems, but the knowledge, training and involvement of those employees directly operating on the site with these systems were discovered to be deficient. Therefore, a generic semi-quantitative hygiene risk assessment model, Hygram®, was developed for small and medium-sized food enterprises to offer assistance in understanding, training, and, first of all, detecting the critical steps of the processes, and thereby to contribute to the development of their own-checking systems towards risk-based food safety management. Hygram® was not considered a risk-based tool as such, but whenever the critical limits of the process have been defined as equal to a risk assessment, Hygram® can be used as a risk-based management tool. It can also serve as a tool for systematic hazard analysis and CCP detection when establishing a food safety management system. To conclude, the development of risk-based food safety management is a process in which risk assessment is an essential tool. Scientific, technical, psychological and resource-bound barriers need to be overcome in order to put risk-based management systems into practice. This study showed that QMRA can be valuable in national risk management decision making, although few QMRAs are currently available. Appropriate tools for practical risk management decision making on the industrial level, such as Hygram®, need to be further developed.
  • Salmivaara, Maikki (Helsingfors universitet, 2013)
    Food has featured in the global development agenda for several decades. However, increasing food prices and the global food crisis of 2007-2008, fuelled the debate around food security, which was also one the main thematic priorities of Finn Church Aid's strategy in 2009-2012. This thesis was commissioned by FCA in order to examine food security in the context of their development cooperation project in Cambodia. The purpose of the study is to support FCA and their local partner organization, the Lutheran World Federation Cambodia’s work on food security. The study has two objectives: to contribute to the understanding of the intertwined issues of rural development and food security, and to the understanding of the food security approach and intervention logics. Firstly, food reality is scrutinized in a Cambodian rural village. The focus is on the functioning of the food system at the local level, and as part of a wider food system reaching beyond the village boundaries and even the national level. In addition, the household level food security is analysed from the perspective of livelihoods - means of gaining a living - and different ways of commanding or accessing food. This level allows scrutinizing how village level changes in the food system affect different kinds of families. Secondly, the study analyses the food security approach of LWF, with regard to the village food reality and in the light of politicised international discourses on food security. The thesis is a contextual case study of the village of Chrokhlong, based on one month’s field work period in November and December 2010, as well as LWF Cambodia’s program documents and interviews with the staff. The field work material consists of 43 interviews with the villagers, 76 informal discussions and personal observation. Food security and general development themes in Cambodia are explored through literature and personal interviews. The study found that the local food security is affected by important changes of the wider food system. Population growth and economic liberalization increase pressures on land and natural resources in the village context. Accumulation and fragmentation of land and degradation of common resources are related to the increasing commoditization of the village food system. Food security has become an issue of purchasing power. Land for rice cultivation appears as the most important factor contributing to household food security. The most food insecure families lack land and means of generating incomes in order to purchase food, such as family members in working age and good health. The poorest families are the most affected by the depletion of common resources and the increasing food prices. At a strategic level, LWF has adopted a holistic approach to food security and defines their objective as 'right to food' in line with a rights based approach to development. However, at the practical level the approach seems narrower, and the work on food security focuses on enhancing food production. This focus risks not taking into account the food insecurity of the land-poor families who do not benefit from increasing productivity. The centrality of the land issue and the specific situation of the most food insecure families is no considered sufficiently. Based on this case study, an integrated and holistic rural development approach would seem to provide relatively more benefits to households that are able to produce to markets, while the food security of the poorest families can be even further threatened by a greater dependence of markets. While LWF’s ideals seem to reflect a 'food justice' discourse, their practical work is more in line with the hegemonic discourse labelled as 'food security', that does not aim at affecting the structural causes of food insecurity at different levels.
  • Salmela, Satu (Helsingfors universitet, 2012)
    Elintarvikelainsäädäntö edellyttää tieteeseen perustuvaa riskiperustaisuutta lainsäädäntöprosessissa. Tieteellisen tiedon tulee asetuksen (EY) N:o 178/2002 mukaan olla keskeisellä sijalla elintarvikelainsäädännön laatimisessa. Suomessa elintarvikelainsäädännön valmisteluun osallistuu huomattava joukko eri toimijoita, jotka edustavat niin elintarvikeketjun eri vaiheita 'pellolta pöytään' kuin eri toimijatahojen edustajia tutkimuksesta kuluttajiin. Jotta tieteellistä tietoa voitaisiin hyödyntää lainsäädäntöprosessissa, tulee sen tavoittaa lainsäädäntöä valmisteleva ministeriö. Useista toimijoista muodostuvan verkoston rakenne voi niin edesauttaa kuin toisaalta vaikeuttaakin tiedon siirtymistä sen tuottajalta – tutkimuksen tekijältä, riskinarvioitsijalta tai tietoa muutoin omaavalta taholta – sen hyödyntäjälle, ministeriölle. Jotta tietoa voitaisiin hyödyntää, tulee verkoston mahdollistaa interaktio eri toimijoiden välillä. Toisaalta lainsäädäntöprosessissa tapahtuvan interaktion eri muodot voivat luoda erilaisia edellytyksiä eri toimijoiden välille. Tässä tutkimuksessa lainsäädäntöprosessin verkoston rakenteen luomia edellytyksiä tieteellisen tiedon hyödyntämiselle elintarvikelainsäädännön valmistelussa tarkasteltiin sosiaali- ja terveysministeriön hallinnonalalla. Tarkastelu kohdistui vuosina 2006–2011 käynnissä olleisiin lainsäädäntöön liittyviin hankkeisiin – lainsäädännön valmisteluun liittyvään lausuntomenettelyyn sekä erilaisten toimielinten jäsenyyksiin. Analyysissä tarkasteltiin niin verkoston rakennetta, eri tapahtumatyyppien vaikutusta verkoston luomien kommunikaatiomahdollisuuksien muodostumisessa kuin verkoston rakenteen luomia edellytyksiä tieteellisen tiedon välittymiselle toimijoiden välillä. Elintarvikesektorin lainsäädäntöprosessin verkoston tarkastelussa keskeisimpiä toimijatahoja sosiaali- ja terveysministeriön hallinnonalalla ovat ministeriöt ja valtion tutkimusta ja/tai riskinarviointeja tekevät keskusviranomaiset, mutta myös muut toimijatahot, kuten erilaiset tutkimusalaa edustavat tahot, ovat edustettuina verkostossa poliittisia toimijoita ja tiedostusvälineitä lukuun ottamatta. Samalla verkostoon ei havaittu muodostuvan erityisiä alaryhmiä. Toimijatahon luonteen ei tutkimuksen tulosten nojalla voida sanoa vaikuttavan suoraan sen asemaan elintarvikelainsäädännön jäsenyysverkostossa, vaan myös tapauskohtaiset lähemmät seikat vaikuttavat toimijatahon asemaan lainsäädäntöprosessissa. Verkoston luomien interaktiomahdollisuuksien, lausuntokierrosten ja toimielinten jäsenyyksien, havaittiin tutkimuksessa olevan yhteydessä toimijan jäsenyyteen verkostossa. Tapahtumatyyppi on yhteydessä sekä siihen, mitkä toimijatahot ja toimijat osallistuvat eri tapahtumiin että siihen, miten usein eri tapahtumiin osallistutaan. Elintarvikelainsäädännön verkoston rakenne mahdollistaa riskiä koskevan tieteellisen tiedon välittymisen elintarvikelainsäädäntöprosessissa. Erityyppiset tapahtumat luovat kuitenkin erilaiset edellytykset tietoa tuottavien ja sitä hyödyntävien tahojen interaktiolle. Lisäksi eri toimijatahoilla on erilainen asema verkostossa, mikä luo erilaiset edellytykset eri tahojen tuottaman tiedon hyödyntämiselle.
  • Kivivirta, Kimmo (Helsingfors universitet, 2016)
    Elintarvikeväärennösten havaitsemiseen käytetään DNA-pohjaisia tunnistusmenetelmiä. DNA-viivakoodaus on tunnistusmenetelmä, jolla pystytään toteamaan laji tuntemattomasta näytteestä lyhyen DNA-jakson eli viivakoodin perusteella. Tämänhetkiset viivakoodit kasveilla sisältävät nukleotiditasolla vähän lajien välisiä eroja, mikä heikentää näytteiden erottelukykyä ja näytteen oikeaa tunnistamista. Viivakoodien erottelukykyä arvioitiin eri puolukoiden (Vaccinium) suvun lajien kesken. Arviointi tehtiin viivakoodeista matK, ycf1, rpoC1 ja ITS. Puolukoiden suvulle ei löydetty viivakoodia, joka kykenisi tunnistamaan täydellisesti näytteitä lajitasolla. Kloroplastiset viivakoodit matK ja rpoC1 onnistuivat parhaiten PCR:ssa, monistamisessa ja sekvensoinnissa. Genomisen viivakoodin, ITS:n monistamisessa ilmeni häiriötä näytteissä, joissa oli vähän DNA:ta. Avoin lukukehys ycf1 puuttuu puolukoiden (Vaccinium) suvulta, mikä esti viivakoodin käyttämistä. DNA-viivakoodeista matK kykeni tunnistamaan BLAST-tietokantavertailussa seitsemän 14:sta näytteestä ja BOLD-tietokantavertailussa yhdeksän näytettä 14:sta näytteestä. ITS kykeni tunnistamaan BLAST-tietokantavertailussa kahdeksan näytettä 14:sta näytteestä. ITS:lle ei ollut riittävästi vastaavuuksia BOLD-tietokannassa ja rpoC1:lle ei kummassakaan tietokannassa. Sekvenssilinjauksessa matK ja rpoC1 olivat lajien välillä hyvin samankaltaisia. ITS sisälsi lajien välillä enemmän variaatiota, mutta tietokannoista puuttui vastaavia sekvenssejä, mistä syystä positiivisia tunnistuksia saatiin heikosti. DNA-viivakoodauksessa kasveilla kahden viivakoodin käyttö on edelleen suositeltavaa lajitason tunnistuksen tarkentamiseksi. Reaaliaikaisella PCR:lla (qPCR) pystytään spesifisesti toteamaan lajin läsnäolo näytteessä havaitsemalla DNA-jaksoja, jotka ovat ainutlaatuisia kohdelajin perimässä. Spesifinen tunnistusmenetelmä pyrittiin luomaan mustikalle (Vaccinium myrtillus) sijoittamalla alukkeet ja koetin lokuksille dfr ja MADS-box. Mustikan spesifisen menetelmän kehittelyssä ei saavutettu täydellistä spesifisyyttä. Mustikan lisäksi myös lajit V. praestans, V. smallii ja V. ovalifolium tuottivat positiivisen signaalin dfr-geenille suunnitelluilla alukkeilla ja koettimella. Positiivista ekspressiota tuottaneet lajit sisälsivät oletettavasti samankaltaisen dfr-geenin, jolle mustikalle spesifiset alukkeet ja koetin sitoutuivat. Spesifinen menetelmä kykeni kuitenkin sulkemaan pois muiden kasvisukujen näytteet sekä suurimman osan puolukoiden suvun näytteistä. Menetelmää voidaan hienosäätää kun dfr-geenin sekvenssi saadaan selville positiivisen signaalin antaneista lajeista tai kun muita suuremman muuntelun alueita paljastuu sekvensoinnin tuloksena.
  • Perkiömäki, Johanna; Leimi, Anna; Tuominen, Pirkko (Evira, 2012)
    4/2012
    Oheisessa selvityksessä on tunnistettu ja kuvattu suomalaisen lehmän ja vuohen raakamaidossa mahdollisesti olevia biologisia vaaroja, joista saattaa aiheutua kuluttajalle terveydellistä haittaa, sekä keinoja riskin vähentämiseksi. Raakamaidon kulutus on ollut Suomessa toistaiseksi vähäistä (n. 1 % maidon ja maitotuotteiden kulutuksesta), mutta käyttäjissä on myös riskiryhmiin kuuluvia kuluttajia. Kuluttajariskiä lisää joissakin kotikeittiössä sovelletut raakamaidon pitkät säilytysajat ja korkeat säilytyslämpötilat. Selvityksen perusteella tärkeimmät biologiset tekijät, jotka voivat aiheuttaa raakamaidon elintarviketurvallisuusriskejä Suomessa, ovat EHEC-, Listeria monocytogenes-, salmonella- ja kampylobakteerit. Ne saattavat aiheuttaa vakavia sairauksia ja jälkitauteja, ja niitä kaikkia on todettu suomalaisissa tuotantoeläimissä, ihmisissä ja navettaympäristössä. Suomalainen elintarviketurvallisuusjärjestelmä ei ota kovin hyvin huomioon raakamaidon tuotannon ja kulutuksen erityisominaisuuksia vaan riskinhallinta perustuu pitkälti hyvien hygieniakäytäntöjen lisäksi maidossa olevia mikrobeja tuhoavaan pastörointiin. Sen vuoksi olisi perusteltua luoda raakamaidon myyntimäärään ja toimintaan suhteutettu yhtenäinen, mahdollisia riskejä ennaltaehkäisevä kansallinen järjestelmä, sekä lisätä raakamaidon kanssa toimivien yritysten ja kuluttajien tietoa hyvistä tuotantotavoista ja turvallisesta käytöstä.