Browsing by Subject "maito"

Aflatoxins are harmful compounds found in food and feed. The literature review of this thesis looked at aflatoxin M1 (AFM1) found in milk and its occurrence, significance and prevention methods using lactic acid bacteria (LAB). Furthermore, the assay methods of aflatoxins and the factors affecting the analysis were discussed. The aim of the experimental work was 1) to investigate the ability of five LAB strains to bind AFM1 in vitro and 2) to investigate how different matrixes affect the assay of AFM1 and to evaluate the feasibility of the selected ELISA kit for the study. In the first phase of the study the AFM1 concentrations of three different matrixes were analyzed using ELISA when known concentrations of the AFM1-standardsolution were added (0, 20 ja 40 ppt). In the second phase of the study the abilities of five LAB strains to bind AFM1 in UHT skimmed milk and MRS-broth were investigated. The bacterial suspensions were incubated at +32 °C for one hour, and the AFM1 concentration in the matrixes were 50, 15 and 10 ppt. The unbound AFM1 concentrations of the supernatants were analyzed from the samples using ELISA. The unbound AFM1 concentrations were converted to the proportional portion of the bound AFM1. In this study, statistically significant differences were observed in the abilities of the LAB to bind AFM1. The viable cells of strain B2 27 (Lb. plantarum-, pentosus- or paraplantarum) were the best binders of AFM1. They removed 43.7 % AFM1 in UHT skimmed milk, where the AFM1 concentration was 15 ppt. Unlike in previous studies viable cells bound AFM1 better than the heat-killed cells. The used ELISA kit was a sensitive method for analyzing low concentrations of AFM1, but at higher concentrations the assay results were inaccurate. The nonspecific interaction due to the components of the matrixes had to be taken into account when the results were reviewed. In the future, it may be possible to utilize the LAB strains, such as B2 27 for reducing AFM1 the concentration in milk and probably in other foodstuffs. There is a need to develop a practical application which can be used in the binding of AFM1 using lactic acid bacteria and thus reduce the bioavailability of AFM1.

Tutkimuksessa selvitettiin enrofloksasiinin farmikokinetiikkaa naudalla eri antotavoilla (s.c., i.m. ja i.v.). Annos kaikilla antotavoilla oli mg/kg. Tutkimusaineistona oli 5 lypsylehmää. Lehmistä kerättiin maito- ja verinäytteitä. Maito- ja verinäytteiden lääkeainepitoisuudet analysoitiin agar-diffuusiomenetelmällä. Tuloksista laskettiin farmakokineettisiä parametreja, joita myös käsiteltiin tilastollisesti. Puoliintumisajaksi i.v. antotavalla saatiin 1,68 h, s.c. antotavalla 5,55 h ja i.m. antotavalla 5,90 h. Ero puoliintumisajoissa on tilastollisesti merkitsevä. I.m. ja s.c. antotavoilla saatu pitkä puoliintumisaika selittyy ns. flip-flop-ilmiöllä. Flip-flop-ilmiö syntyy, kun imeytyminen antokohdasta on niin hidasta, että se rajoittaa eliminaatiota. Tilastollisesti merkittävä o saatiin MRT-arvolle (mean residence time, keskimääräinen viipymisaika) i.v. ja i.m. antotavan ja i.v. ja i.m. antotavan välillä. Huippupitoisuuksissa ei ollut merkittävää eroa eri antotapojen välillä. Keskimääräinen enrofloksasiini-pitoisuus seerumissa annosvälillä 12 h annettuna suonensisäisti annoksella 5 mg/kg oli 0,617. Tämä pitoisuus ylittää useimpien gram-negatiivisten bakteerien MIC-arvon. Enrofloksasiini siirtyy hyvin maitoon. Keskiarvopitoisuudet maidossa 12h kohdalla eri annostelutapojen jälkeen vaihtelivat välillä 0,63 mg/1-1t,51 mg/l. Tavallisimpien gram-negatiivisten mastiittipatogeenien Mic_90-arvo on välillä 0,03 mg/1-0,13 mg/1. Suuren kudosärsyttävyytensä vuoksi enrofloksasiini olisi annosteltava i.v. Enrofloksasiini vaikuttaa farmakokinetiikaltaan sopivalta lääkeaineelta lypsylehmien lääkintään. Sopivia indikaatioita olisivat mm. E. coli- ja Pasteurella-bakteerien sekä mykoplasmojen aiheuttamat infektiot (esim. hengitystietulehdukset).

Ruoka ei ole pelkästään ravintoa, vaan kulttuurinen tuote, joka tuo elämään pysyvyyttä. Saatavilla oleva ruokavalikoima on laajentunut ja monipuolistunut globalisoidun talouden arkipäiväistyttyä, mutta juusto on ollut ja pysynyt osana ravintoamme jo keskiajalta lähtien. Vuonna 2022 juustoa kulutettiin 25,5 kiloa yhtä suomalaista kohti. Suomi on noussut Ranskan rinnalle yhdeksi eniten juustoa kuluttavaksi maaksi maailmassa. Tästä huolimatta Suomessa ei ole tutkittu juustoa kulttuurisena ilmiönä. Tämän tutkielman tavoitteena on ymmärtää juuston roolia suomalaisessa ruokakulttuurissa ja paneutua juustoon osana syömisen käytäntöä. Käytännöt ymmärretään kokonaisuutena, joka koostuu toisiinsa liittyvistä elementeistä. Tässä tutkimuksessa nojaudutaan käytännön elementteihin: materiaaleihin, osaamisiin ja merkityksiin. Käytäntö nähdään toimintana, jolla on erilaisia merkityksiä ja jonka toteuttamiseen tarvitaan osaamista eli kyvykkyyttä tehdä asioita sekä konkreettisia objekteja eli materiaaleja. Käytäntöjen teoriassa korostuu toiminta yksilön käyttäytymisen tarkastelun sijaan, vaikka ihminen nähdäänkin merkittävänä käytäntöjen suorittajana ja kantajana. Tutkimus toteutettiin laadullisena tutkimuksena. Aineisto kerättiin vuoden 2023 helmikuun ja toukokuun välillä puolistrukturoiduin haastatteluin. Aineisto koostui kymmenestä haastattelusta. Haastateltavat olivat 27–73-vuotiaita Uudellamaalla asuvia miehiä ja naisia. Kerätty aineisto analysoitiin teemoittelemalla käytäntöteoreettista näkökulmaa hyödyntäen. Tutkimuksen tulokset osoittavat, että haastateltavat antavat juustolle niin sosiaalisia kuin kulttuurisia merkityksiä. Juusto on itsessään materiaali, jota hyödynnetään niin leivän päällä, ruoanlaitossa, leivonnassa kuin herkutteluhetkissä. Juustosta ei mielellään luovuta sen monipuolisuuden ja ainutlaatuisuuden vuoksi. Juustoon liittyy tutkimuksen perusteella laajaa osaamista aina eri juustotyyppien tuntemuksesta sen lukuisiin käyttötarkoituksiin. Myös juustonvalmistuksen eettiset ja ekologiset ulottuvuudet olivat haastateltavien tiedossa. Erityisesti eläinten hyvinvointiin liittyvät ongelmat aiheuttivat huolta. Osa haastateltavista oli valmis kokeilemaan tai jopa osittain siirtymään juustoa korvaaviin kasvipohjaisiin tuotteisiin. Tutkimuksen tulokset viittaavat myös siihen, että juusto osana suomalaista syömisen käytäntöä on mahdollisesti vähitellen murtumassa, kun tietoisuus muun muassa eettisistä ja ekologisista ulottuvuuksista erityisesti nuorten keskuudessa on lisääntymässä.

The aim of this study is to examine what kind of discourses can be found in the public expert debate in the news media and in the public lay discourse from the news media comment field regarding the Milk Myths campaign. Milk has a historically strong position in Finnish food culture, and because of this Milk Myths campaign has caused a stir. The theoretical framework of the dissertation is related to Finnish food culture, its tension and changes, food policy and food in media discussions. The topic is strongly connected to the Finnish food culture and its tensions. The changes and tensions in the food culture are notoriously discussed and may create confrontations between interlocutors. The research questions are: 1 What kind of discourses can be found in the expert speech related to Oatly’s Milk Myths campaign in the news media? 2 What kind of discourses can be found in the public debate about Oatly’s Milk Myths campaign? The material for the dissertation was three news articles and one news comment field based on Milk Myths campaign. The news articles were found in Helsingin Sanomat, Iltalehti and MTV. The comment field was related to Helsingin Sanomat’s news coverage Milk Myths campaign. The data was analyzed using discourse analysis. The discourses found in the news material were named health, environmental and economic discourses, as well as a discourse of confrontation. The discourses found in the public debate were named the discourses on the defense of milk and animal welfare, as well as the discourse on a boycott, the environment and Finnishness. In conclusion, the discourses found the research were tense both internally and with other discourses. The discourse was as polarized and dichotomous as the discourse found in previous studies regarding food wars.

Maito on herkästi pilaantuva elintarvike, jonka laadun keskeisiä osatekijöitä ovat solu- ja bakteeriluvut. Maidon laadussa on havaittu vuodenaikaisvaihtelua: helteiden yhteydessä erityisesti maidon soluluku nousee. Ilmastonmuutoksen myötä keskilämpötilan ja sään ääri-ilmiöiden odotetaan lisääntyvän, minkä vuoksi sään ja maidon laadun välistä yhteyttä tulisi selvittää tarkemmin. Tutkielman tavoitteena oli selvittää tilastollisten menetelmien avulla keskilämpötilan ja sademäärän yhteyttä Suomessa tuotetun tankkimaidon solu- ja bakteerilukujen valtakunnallisiin keskiarvoihin sekä maidon laatuluokkien (E, II) osuuksiin. Aineistona käytettiin Maitohygienialiiton maidon laatutilastoja, Ilmatieteen laitoksen säätilastoja ja Luonnonvarakeskuksen tilastotietokantoja vuosilta 2000–2019. Työn ensimmäinen hypoteesi oli, että lämpötila ja sademäärä ovat yhteydessä tankkimaidon solu- ja bakteerilukuihin. Työn toinen hypoteesi oli, että lämpötila ja sademäärä ovat yhteydessä maidon laatuluokkien osuuksiin. Tutkimustulosten perusteella lämpötila on yhteydessä solu- ja bakteerilukuihin sekä E-luokan maidon osuuteen. Riippuvuus soluluvun ja E-luokan maidon osuuden välillä kasvoi, kun kuukauden keskilämpötila kohosi yli 5 °C:een. Keskilämpötilan noustessa 5 °C:sta 15 °C:een, soluluvun geometrinen keskiarvo kasvaa noin 17 % (22 000 solua/ml), bakteeriluvun geometrinen keskiarvo kasvaa noin 12 % (700 pmy/ml) ja E-luokan maidon osuus putoaa keskimäärin kolme prosenttiyksikköä. Yli 15 °C:ssa trendi on edelleen nouseva, mutta vaikutus on huonommin ennustettavissa suurentuvan hajonnan vuoksi. Sademäärän ja vastemuuttujien välinen yhteys oli voimakkuudeltaan vähäinen.

Milk production in Finland has changed during the latest decades. There are significant changes in cattle breeding, cattle feeding, milk collecting and transportation. Also processing of milk products has been developed. In addition, milk products are consumed in a different way than before. For example the consumption of fat-free milk and cheeses has increased whereas overall consumption of milk has decreased. In this master’s thesis milk products of DIPP (Diabetes Prediction And Prevention) nutrition study were classified based on their homogenization and heat-treatment. Creating the classification, the effects of heat-treatment or homogenization on milk proteins and fat globules were considered. The classification was done using information provided by literature and by major dairy manufacturers. Milk products were classified in one of the following groups based on the homogenization information: homogenized, non-homogenized, fat-free; and in one of the following groups based on the heat-treatment information: normally pasteurized or milder heat treatment, high pasteurized at < 100°C, high pasteurized or sterilized at ≥100°C. Milk consumption of children at the age of 6 months (n=1305), 1 year (n=1513) and 3 years (n=1326) was observed using both the updated classical DIPP - milk product classification and the newly created processing based classifications. It was observed that children used a lot of strongly heated milk-based products especially during their first year. At the age of six months mostly high pasteurized or sterilized at ≥100°C and homogenized milk products were used. Background variables such as breastfeeding, mother’s education and children’s living area (Pohjois-Pohjanmaa/ Pirkanmaa) were associated with milk product consumption both when using classical and process based classifications. This study introduces new information about children’s milk product consumption. The process based classification can also be used later when observing whether consumption of some specific kind of milk products can lead to appearance of type 1 diabetes.

The literature review of this thesis deals with light, different light sources and their properties. LED (Light Emitting Diode) light was specially taken into consideration, because the use of LED lights will increase in general illumination. The literature review also deals with the quality changes of dairy products and potatoes caused by exposure to light. The aim of this study was to search for such a spectral distribution of light which would cause only minor changes in the sensory quality of milk and the surface colour of potatoes. Objective was to also find out if there is a difference between the effects of fluorescent light and LED light on the quality of milk and greening of potatoes. Reduced (1,5 %) fat milk and new potatoes were used as testing materials. The milk in commercial carton board packages was exposed to six different light sources: white fluorescent lamp, white LED and LED of four different colours. The potatoes packed in transparent LDPE (Low Density Poly Ethylene) bags were stored under five different light sources: white fluorescent lamp, white LED and LED of three different colours. The light intensity at the surface of the packages was about 1000 lx in both studies. In the milk study, the effects of light were evaluated with a sensory method using descriptive analysis. In the potato study, the light effects were analysed with colour measurements (avalue) using a spectrophotometer and with surface temperature measurements using a laser thermometer. Sensory evaluation of milk there resulted in few statistically significant differences in the intensity of the attributes between the milks stored under different light sources. Light exposure caused a rapid greening of potatoes in every illumination. According to colour change percentage, the greening order under different lights was: white LED < yellow LED < green LED < turquoise LED < fluorescent light. The potatoes which were stored in dark had no change in their surface colour. The surface temperature of potatoes increased most under white LED and turquoise LED lights. A spectral distribution of light which would have caused less changes in sensory quality of milk than commonly used fluorescent light was not found in this study. The results showed, however, that in addition to blue light which has always been considered the most harmful for milk the red light also caused remarkable quality changes. Based on the results of this study, it could be suggested that under the LED lights the quality of packed milk retained its quality characteristics at least as well as under the fluorescent light. There were differences between the effects of different lights on the greening of potatoes. White and yellow LED light caused less greening of potatoes than the other lights. The strongest greening of potatoes was observed under the fluorescent light.

Tämän tutkielman tavoitteena oli selvittää, mitkä eri tekijät vaikuttavat kuluttajan ostopäätökseen, kun ostetaan maitoa kaupasta. Tutkimuksen lähestymistavaksi valittiin kvalitatiivinen tutkimus ja tutkimusmenetelmänä käytettiin yksilöhaastattelua. Haastatteluiden avulla haluttiin selvittää, että mitä eri tekijöitä kuluttajat pitivät tärkeinä maidon ostopäätökseen liittyen. Tutkimuksessa haastateltiin kahtakymmentä eri-ikäistä ja eri sosiaalisen aseman omaavaa henkilöä. Rajauksena tutkimuksessa oli ainoastaan, että haastateltavan henkilön oli ostettava säännöllisesti maitoa kaupasta. Tutkimuksen teoreettinen viitekehys muodostettiin kirjallisuuskatsauksen ja aikaisempien tutkimuksien perusteella. Tutkielmassa keskityttiin seuraaviin tärkeisiin tekijöihin: brändi ja imago, hinta, kotimaisuus ja ostopäätösprosessi. Tutkimuksen perusteella voidaan todeta, että maidon brändillä ja imagolla oli suuri merkitys kuluttajan ostopäätösprosessiin. Myös maidon kotimaisuus oli tärkeä tekijä kuluttajille. Haastatteluissa selvisi myös muita tekijöitä, jotka vaikuttivat maidon ostopäätösprosessiin, kuten maidon hinta tai maitopurkin koko. Nykyään kuluttajat keskittyvät paljon ruoan tuotantotapojen eettisyyteen, mistä seurauksena monet yritykset tuovat tulevaisuudessa markkinoille yhä enemmän luomutuotteita ja lähiruokaa. Tulevaisuudessa kuluttajat suosivat kestävän kehityksen mukaan tuotettuja elintarvikkeita ja yritysten on pystyttävä vastaamaan tuotevalikoimalla tähän trendiin.

It is necessary actively seek effective ways to reduce agricultural emissions so that the proportion of agricultural greenhouse gas emissions in total national emissions does not increase. The aim of this study was to evaluate with carbon footprint calculators different options for reducing greenhouse gas emissions of dairy production and the carbon footprint of energy-corrected milk. The scenarios included the changes in the dietary concentrate proportion, the proportion of grass in cultivation, the digestibility of roughage and the level of milk production. In addition, the effect of temperature on methane emissions from manure was examined. Data of a dairy farm located in Central Ostrobothnia from year 2020 were utilized in the study. The assessment was carried out by using the carbon footprint calculator developed by the European Commission and the Valio Carbo® environmental calculator. According to the results of both calculators, the effect of the changes in the concentrate proportion in the diet on the carbon footprint of milk was very small. Reducing the proportion of concentrate in the diet reduced total emissions. Reducing the proportion of rapeseed meal in feeding reduced total emissions more than reducing the proportion of barley. Increasing the proportion of grass in cultivation reduced the carbon footprint of milk and the total amount of greenhouse gas emissions with both calculators. According to the European Commission carbon calculator, increasing grass yield and also increasing the proportion of grain in cultivation reduced the carbon footprint of milk and the total amount of greenhouse gas emissions. With Valio Carbo® environmental calculator, increasing the proportion of grain in cultivation increased the carbon footprint of milk and the total emissions. According to European Commission calculator, the total emissions and the carbon footprint of milk decreased when the digestibility of roughage decreased. The increase of milk production level also clearly reduced the carbon footprint of milk with both calculators. However, the change in the milk production level had only a small effect on the amount of emissions produced. Reducing the conversion factor describing the effect of temperature on methane formation from slurry reduced the carbon footprint of milk. The decrease in the conversion factor reduced the emissions from the manure system by 51.3 percentage and reduced the milk carbon footprint from 1.21 to 1.15 kg CO2e/kg ECM. In conclusion, there are many feasible opportunities to reduce the carbon footprint. The most effective ways to reduce total emissions at farm level are to increase the proportion of grass in cultivation and to increase the yield of grass. Raising the milk production level effectively reduces the carbon footprint, but in the future the calculations must take into account that the dry matter intake is higher as the milk yield increases. The main differences between the calculators are currently in the coefficients they use. When comparing the results given by the calculators, it is important to note that the calculation principles cannot fully take into account the possible opposite effects of different factors. The results should be looked critically with a caution that the results given by different calculators are not directly comparable.

Milk fat contains a lot of (70–75 %) saturated fat, which is connected to Finnish public heart and coronary diseases. However, it is possible to alter the fatty acid composition of milk fat by giving cows lipid supplements such as crushed rapeseeds. The aim of this pilot study was to investigate how the lipids of crushed rapeseeds affect dairy cow’s milk fatty acid composition. The effects of rapeseed lipids on saturated and unsaturated fatty acid concentrations in milk fat were studied in particular. Additionally, it was investigated how dietary lipids affect cows’ dry matter (DM) intake and milk production as it is known that high amounts of lipids can reduce DM intake and fiber digestion in the rumen. The study consisted of two successive three week long periods of which the first one was control period and the second one test period. There were six ayrshire cows which had been on average 181 days in milk at the beginning of the study. The cows were given partial total mixed ratio (pTMR) containing grass silage as forage (60 % of diet DM) during the whole study. Concentrates comprised cereals, rapeseed meal, molassed sugar beet pulp and mineral supplements. Control diet’s barley was replaced by oats and most of the rapeseed meal was replaced by crushed rapeseed in the test diet. Crushed rapeseed was added 160 g/kg pTMR DM. Cows were also given complete feed 3kg/day at milkings. Lipids of crushed rapeseeds reduced the concentration of saturated fatty acids by 20 % in milk fat. Of all the saturated fatty acids, palmitic acid (C16:0) was decreased by 38 % and stearic acid (C18:0) was increased by 94 %. Of these two saturated fatty acids, C16:0 is linked to higher total plasma cholesterol levels whereas C18:0 is considered to have a neutral effect in humans. The concentration of monounsaturated oleic acid (cis-9 C18:1), which is known to be hypocholesteremic, increased by 78 % in milk fat. Test diet caused decline in DM intake and milk production. It is likely that the milk production decreased partly because the cows were in declining milk production phase. Test feed decreased the apparent digestibility of neutral detergent fiber (NDF), because the amount of rapeseed lipids in the diet was high (48 g/kg diet DM). Crushed rapeseeds suit excellently to alter dairy cow’s milk fatty acid composition. The amount of lipid supplementation should not be too high in order to avoid decreases in DM intake and NDF digestibility as occurred in this study.