Browsing by Subject "aistinvarainen arviointi"

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  • Wickman-Viitala, Tiina (Helsingin yliopisto, 2020)
    There is growing concern about the world population growth and the sufficiency of protein resources. Edible insects could be an alternative protein source for human beings. The aim of this master thesis was to examine the sensory characteristics of a new home cricket (Acheta Domesticus) product and understand the attitudes of consumers towards edible insects. The aim was to investigate the impact of consumer familiarity with edible insect food products on purchase intention and expected liking. The roles of media trust and purchase activism were expected to affect the behavior of consumers. Besides these four indicators also two more were added. These were food neophobia scale and innovativeness. The data on consumer attitudes and perception towards insect food was collected by using an electronic form that was sent to different mailing lists. Total of 167 respondents were gathered, 141 women and 63 men. 53 participants attended the sensory analysis tests on the beginning of the year 2020, ages 18 – 62. The analysis of the data was done with SPSS Statistics version 25. The findings of this study indicate that consumer familiarity contributes to purchase activism, purchase intention and expected liking. In this study the media trust did not contribute. Food neophobia scores correlated negatively to the intention to buy, expected liking and willingness to recommend the product. Innovativeness correlated positively to intention to buy and expected liking, and as expected, innovativeness correlated negatively to food neophobia scores. As people learn more about the ecological and nutritional benefits of edible insects, their attitudes towards insect food become more positive and they are more willing to try and taste insect products. The new home cricket product, PANNU Sirkka by GRiiDY, turned out to be quite suitable for Finnish consumers taste. On the just-about-right scale (1–4) the average score was 3,3 – 3,8 of all the assessed attributes. Many of the open responses mentioned the product to be ‘tasty, delicious, surprisingly good and crispy’, for instance. To overcome the preconceptions of western consumers, there should be more occasions to try and taste insect food. Marketing efforts are best targeted to consumers who are neophilic and innovative and encourage them to be the early adopters of insect food.
  • Päivärinta, Katariina (Helsingin yliopisto, 2019)
    Hajuammattilaisuudella, hajuharjoittelulla ja muulla systemaattisella hajuille altistumisella on merkittävää vaikutusta hajuaistin toimintaan. Muutokset näkyvät esimerkiksi hajuaistin herkkyydessä sekä kyvyissä havainnoida, tunnistaa ja erottaa hajuja toisistaan. Tämän maisterintutkielman tavoitteena oli selvittää eroavatko aistinvaraisen arvioinnin ammattilaiset ja elintarviketieteiden opiskelijat toisistaan hajujen tunnistamisen, kokemisen ja ruokamieltymyksien suhteen. Tutkimuksen hypoteesien mukaan ammattilaiset olisivat parempia tunnistamaan hajuja, kuvailisivat niitä useammilla sanoilla ja arvioisivat ne keskimäärin tutummiksi sekä heillä olisi vähemmän ruokainhokkeja. Lisätavoitteena tutkimuksessa oli myös tarkastella mahdollisia hajunäytteiden välisiä eroja. Tutkimuksen merkityksenä oli olla osa aistinvaraista perustutkimusta ja tuottaa uutta tietoa vähän tutkitun hajuammattilaisten alatyypin, elintarvikkeiden aistinvaraisen arvioinnin ammattilaisten, hajuaistikyvyistä. Tutkimukseen osallistui yhteensä 85 koehenkilöä, joista aistinvaraisen arvioinnin ammattilaisia oli 23 kpl, elintarviketieteiden opiskelijoita 56 kpl ja muiden alojen opiskelijoita tai työntekijöitä 6 kpl. Tutkimus koostui kolmesta osasta, jotka olivat hajujen tunnistustesti, hajunäytteiden arviointitehtävä sekä verkkokysely. Hajujen tunnistustestissä koehenkilöiden hajuaisti testattiin 32 hajun Sniffin’ Sticks-tunnistustestillä. Hajunäytteiden arviointitehtävässä näytteitä oli 6 kpl (β-jononi, tyrni, L-karvoni, valkosipuli, D-karvoni, balsamico) ja niistä tutkittiin koettua miellyttävyyttä, voimakkuutta, tuttuutta ja laatua. Verkkokyselyllä kartoitettiin koehenkilöiden ruoka-asenteita ja suhtautumisia erilaisiin ruokalajeihin ja ainesosiin. Tutkimuksessa havaittiin ammattilaisten olevan parempia tunnistamaan hajuja ja kuvailevan niitä useammilla sanoilla kuin opiskelijat. Ammattilaiset eivät kuitenkaan arvioineet hajuja keskimääräisesti tutummiksi eikä heillä ollut tilastollisesti merkitsevästi vähemmän ruokainhokkeja. Hajunäytteiden keskinäisessä vertailussa havaittiin eroja hajujen välillä. Miellyttävimmäksi arvioitu β-jononi oli myös hajuista vähiten tuttu ja voimakas. Voimakkaimmaksi ja epämiellyttävimmäksi arvioitiin balsamico, kun taas tutuin haju oli valkosipuli.
  • Järvelä, Anu (Helsingfors universitet, 2011)
    The fish processing industry requires a method by which shelf life of whitefish could be reliably assessed in real time. Quality Index Method (QIM®) has been used in several European countries for many different species of fish. QIM® predicts the remaining shelf life of fish species based on changes in sensory characteristics. The aim of the present study was to create the QIM® for sea-farmed whitefish, the first QIM® for Finnish fish, which could be included in the official QIM® folder. The study was conducted in the Finnish Food Safety Authorty (Evira). Examined fishes were purchased from Kalatukku E. Eriksson Ltd. pH value and a microbiological method were used to evaluate shelf life. Sensory profiles were created (n = 13). Two profile panels (n = 9) and the QIM® panel (n = 5) evaluated the raw and cooked fish. The result was also ensured by quality scoring for fish (Evira 8001). The QIM® panel created a draft for the QIM® frame, and the draft was further tested. Photos of fresh fish samples were taken. The QIM® draft created according to this study was an effective basis for initiating the validation of the QIM® prepared. It can also be noted that the QIM® itself was suitable for sea-farmed whitefish. Cooked fish analysed with a sensory evaluation method (Evira 8001), and found the time when you can find spoiled taste of from cooked fish and the examination of raw fish can be stopped. The microbiological method “Determination of the number of microbes” (Evira 3420/1) correlated with the QIM® result, fish samples were polluted on the fifteenth day. The pH results did not provide reliable results with which the QIM® result could have been compared. The prepared QIM® created for the sea-farmed whitefish could be utilised in the future in the Finnish fishing industry. It would be useful if QIM® was created for the other most common Finnish trade fish, so that the expiry dates on packages would be based on one common method, and thus the last day of use would have a scientific basis.
  • Peltoniemi, Anna (Helsingfors universitet, 2012)
    Current domestic, commercial apple cultivars seem to have relatively short shelf life and there is only little information available about sensory changes during storing. Apple production is increasing and at the same time there is challenge to produce cultivars with long shelf life. The aim of this master thesis was to study the sensory characteristics of domestic apple cultivars during storage and to create sensory profiles for the apples. Soluble dry matter and dry matter were measured instrumentally during the storage. The objective was to study in which of the attributes the storage causes most effects and how long does it take for these effects to appear. Descriptive analysis (n=14, 2 replicates) was used to examine the sensory characteristics of 16 cultivars harvested in the autumn of 2010. The cultivars were classified as autumn (Jättimelba, Petteri, Samo, Vuokko, Heta, Discovery, Pekka, Summerred) and winter cultivars (Eva-Lotta, Konsta, Punainen Atlas, Tobias, Aroma/Amorosa, Lobo, Y9330, Åkerö Hassel). The lexicon was based on the descriptive analysis of apples from the previous autumn and consisted of 23 sensory attributes: six related to appearance (green, red, relative area of red, surface wax, outside and inside browning), six to texture (hard, crispy, toughness of peel, mealy, juicy, soggy), five to odour (intensity, grassy, fruity, alcoholic, mouldy) and six to flavour (intensity, sour, sweet, astringent, diversity, alcoholic). The cultivars were stored in a traditional cold storage (+3 °C, RH 80–92 %) and the evaluations were conducted 2–5 times during the storage. The storage had the most effects on the textural and flavour attributes. Almost all attributes differentiated between the cultivars. In the basic sensory profiles only the grassy and mouldy odour and in the storage test the appearance green, the odour intensity and grassiness, the sweet flavor and soggy texture didn’t make difference. Diversity and sweet flavor and fruity odour were explained better by soluble dry matter. Y9330, Eva-Lotta, Aroma/Amorosa, Discovery and Summerred showed a promising capacity for extended shelf life of up to 15 weeks.
  • Toppinen, Laura (Helsingin yliopisto, 2020)
    Global food production contributes to 25-30% of total greenhouse gas emissions and the environmental effects of the food system are estimated to even rise 50-90 % by year 2050. A shift to plant-based diets and the use of meat alternatives can address the growing health and environmental problems related to animal-based food consumption. However, off-flavors may limit the utilization of plant-based proteins in food applications by creating challenges concerning sensory quality and consumer acceptance. The aim of this study was to test if LAB fermentation can improve consumer perception of an oat and legume-based product. Furthermore, this study explores consumer perceptions of plant-based protein products, factors related to their consumption and whether flavor of these products might be a barrier to use. The consumer study included a sensory evaluation (N=135) and a web survey (N=1442). In the sensory study consumers evaluated the pleasantness of a fermented plant-based protein product and a non-fermented reference sample in addition to attributes related to odor and taste. Consumer views and attitudes towards plant-based protein products were studied in the web survey. The effects of fermentation on the sensory properties of the plant-based protein product were very small, yet statistically significant. Consumers found the fermented sample to be more pleasant overall and in smell. The odor of the fermented sample was also found less earthy, but the taste slightly more bitter compared to the reference sample. The results suggest that fermentation could be used as a method to reduce earthy flavors of plant-based protein products and thus increase consumer acceptance. Based on the results to the survey, taste, health, environmental impact, ethical reasons, price, domestic origin and easiness to prepare were the most important factors in food choices of the respondents. Characteristics of the participants show that consumers with frequent consumption of plant proteins were overrepresented in the sample so the findings cannot be extended to general population. Overall, the sensory properties of plant-based protein products were perceived as quite pleasant among the respondents and as many as 83 % (N = 1197) agreed that these products taste good. This study presents that flavor and particularly odor of plant-based protein products might act as a barrier to use especially to consumers that are not familiar with these products.
  • Mäkipelto, Anni (Helsingfors universitet, 2015)
    Maisterintutkielman kirjallisuusosassa perehdyttiin tuorejuustoihin ja niiden valmistusmenetelmiin. Tässä tutkielmassa tutkittiin pääasiassa leikattavan tuorejuuston kolmea eri valmistusmenetelmää: säkitys-, ultrasuodatus- ja rahka-rasvaseosmenetelmää. Kirjallisuusosassa käsiteltiin lisäksi tuorejuustojen koostumusta, valmistusmenetelmien kannattavuutta, kuten tuorejuustosaantoa ja laatuominaisuuksia. Kokeellisessa osassa valmistettiin leikattavaa tuorejuustoa pilot-mittakaavassa ultrasuodatus- ja rahka-rasvaseosmenetelmällä ja verrattiin teollisesti säkitysmenetelmällä valmistettuun leikattavaan tuorejuustoon. Näytteistä tutkittiin valmistusmenetelmien vaikutuksia leikattavan tuorejuuston valmistusprosessiin, laatuun, rakenteeseen, aistinvaraisiin ominaisuuksiin, säilyvyyteen ja kannattavuuteen. Tuorejuustojen aistittavaa laatua tutkittiin perinteisen miellyttävyystestin avulla ja rakennetta erilaisin rakennemittauksin. Lisäksi juustoista määritettiin kemiallinen koostumus ja mikrobiologinen laatu. Eri valmistusmenetelmillä valmistetut leikattavat tuorejuustot erosivat toisistaan tilastollisesti merkitsevästi joiltakin rakenteellisilta ja aistinvaraisilta ominaisuuksiltaan. Yksi leikattava tuorejuustonäyte koettiin kokonaisuudessaan miellyttävimmäksi kaikilta arvioitavilta ominaisuuksiltaan. Lisäksi rakennemittausten tulokset tukivat hyvin kuluttajien aistinvaraisia arviointeja. Tuorejuustojen säilyvyyttä tutkittiin siten, että rakenne- ja mikrobiologisista määrityksistä tehtiin toistomittaukset viiden viikon kuluttua valmistuksesta. Toistomittauksien avulla voitiin tarkastella rakenteen ja mikrobiologisten tulosten muuttumista säilönnän aikana. Säilyvyys oli pysynyt hyvänä lukuun ottamatta säkitysmenetelmässä mikrobien pesäkemääriä, joiden tulosta vääristivät maitohappobakteerit.
  • Varis, Jutta (Helsingfors universitet, 2017)
    Faba bean (Vicia faba L.) is an economical, sustainable source of vegetable protein. Antinutrients and unpleasant flavor restrict its use for animal feed and human consumption. Addition of faba bean flour or other protein rich bean flours has a big influence on the structure and flavor of baked products. The aim of this study was to find out how the structure and sensory profile changed when native faba bean (NHP) flour or fermented faba bean (RHP) flour was added to wheat bread. The study was organized into two substudies 1) The wheat breads were baked with 0–50 % faba bean flour (NHP0, NHP10, NHP30, NHP50) 2) The breads were baked with 30 % faba bean flour fermented with four different lactic acid bacteria (R1HP, R2HP, R3HP, R4HP and control sample NHP30r). Generic descriptive analysis (GDA) was used for evaluations (n = 12). NHP breads were evaluated with 13 attributes: five related to an odour, two to colour, four to texture and two to taste. In RHP evaluation, three attributes were added: musty odour, crumb musty taste, and crumb sour taste. The analysis of variance showed that the amount of faba bean or the type of fermentation had an effect in each attribute except in odour of yeast in RHP breads. NHP30 control samples were evaluated similarly in both substudies. High levels of faba bean (NHP30, NHP50) made the intensities of odour and flavour stronger and texture less smooth compared to wheat bread with lower levels of faba bean. Weissella confusa fermented bread (R1HP) differed considerably from other fermented samples in texture, specific volum, colour and in some odour and flavour attributes. The Weissella confusa E3403-strain, used in bread R1HP, produces exopolysaccharides, which transforms the technological attributes of faba bean flour more suitable for wheat baking. The Weissella confusa E3403-strain also excludes the negative side effects affecting the taste and texture and enables the high faba bean and protein level in wheat bread.
  • Saarimaa, Kaisa (Helsingin yliopisto, 2018)
    Maisterintutkielman kirjallisuuskatsauksessa perehdyttiin naudan jauhelihan laatuun ja pilaantumi-seen vaikuttaviin tekijöihin alkaen naudan kasvatuksesta ja päättyen valmiiksi jauhelihapak-kaukseksi. Tutkimuksen kokeellisen osan tarkoituksena oli selvittää, mitkä tekijät vaikuttavat jau-helihan säilyvyyteen nykyisessä prosessissa ja millä tavoin säilyvyyttä voidaan parantaa. Tutki-muksessa valmistettiin rasvapitoisuudeltaan 17 % naudan jauhelihaa kolmella eri reseptillä. Resep-teistä valmistettiin näytteet kahdella eri prosessinopeudella. Tutkimuksessa tehtiin 12 vuorokauden säilyvyyskoe kuudelle eri näytteelle. Aistinvaraisessa arvioinnissa näytteiden väriä tutkittiin 3- ja 7-portaisilla asteikoilla sekä näytteiden värivirhettä 9-portaisella asteikolla, n=3 (asiantuntijaraati). Kolmiportainen asteikko oli kuvattu arvosanoilla hyvä, tyydyttävä, huono. Seitsenportaisessa asteikossa joka toinen sana oli kuvattu väreillä kirkkaanpunainen, punainen, harmahtava ja harmaa, ja asteikon tueksi oli laadittu värikart-ta. Värivirheasteikossa joka toinen sana oli kuvattu: ei värivirhettä, hento värivirhe, pieni värivirhe, kohtalainen värivirhe ja äärimmäinen värivirhe. Laboratoriotutkimuksissa mitattiin pakkauksien suojakaasuista happi ja hiilidioksidi, määritettiin näytteiden kokonaisbakteerit sekä mitattiin pH ja rasvapitoisuus (%). Näytteitä tutkittiin valmistuspäivänä ja kun niiden ikä oli 4, 6, 10 ja 12 vuoro-kautta. Tuloksissa huomattiin, että reseptillä oli tilastollisesti merkitsevä p<0,001 ero aistinvaraisten arvi-ointien tuloksiin. Massan jäähdyttäminen hiilidioksidilla huononsi jauhelihan väriä. Lisäksi se nosti hiilidioksidin ja laski hapen määrää pakkauksessa. Pakasteraaka-aineen osuuden lisääminen kasvat-ti näytteiden kokonaisbakteerien määrää. Prosessinopeuden nopeuttaminen auttoi ylläpitämään jauhelihan punaista väriä pitempään.
  • Ylitalo, Anna (Helsingin yliopisto, 2019)
    People are eating a lot of ice cream all over the world and new products must be developed to create new options for consumers. Unilever, for whom this thesis has been made, is interested in developing new ice cream structures. The objective of the thesis was to explore different possibilities of ice cream structures and create two new interesting structures to the ice cream market; one with long, stretchy and chewy texture and one with high overrun (HOR) and light mouthfeel. The idea was to change the amounts, types and mixes of emulsifiers and stabilizers from the recipe. Additionally, process parameters, homogenisation and overrun, were changed from the current values. Hence, the purpose was to influence the size and amount of air bubbles and fat globules. The study was conducted at Unilever Sipoo, Ingman ice cream factory at their pilot plant. In the experimental part of the study, various versions of new ice cream structures were tested and compared to the reference product. After sensory analysis, it was decided to proceed with three versions of the HOR structure and two versions of the stretchy structure. At the end there were five versions of two new structures produced and analyzed with various tests. The analytical methods suitable and available for this study were viscosity measurement, shelf-life test, chemical test and melting test. Furthermore, there were small sensory analysis done during the study and comprehensive, final sensory analysis was done at the end of the study, for the final products. In conclusion, both of the new structures succeeded well. The “HOR E NAS 4” proved to be the best version of the structures. The melting profile of “HOR E NAS 4” ice cream corresponded the reference product. The results of the shelf-life test were positive: all the new structures survived better than the reference product. Sensory evaluation showed that the structures differed statistically significantly from each other and especially from the traditional ice cream, which was the aim of the study. The “HOR E NAS 4 “ was evaluated to be more firm and not so creamy as the reference product, which have to take in consideration in further investigations. “HOR E NAS 4” will be published on the ice cream market next year, as a new product.
  • Matikainen, Laila (Helsingin yliopisto, 2019)
    This Master's thesis compares the commercial cooking tests of potatoes in Finland and Europe. The cooking type comprises the structural properties of potato, which are described e.g. in terms of floury and waxy or types A-D. Other measures of cooking quality, such as color, taste and odor, were excluded from the work. The main focus of the thesis was on the survey of European cooking type tests and on the comparative study of descriptors for different varieties. As the use of descriptors and terminology differ slightly from one country to another, the significance of the differences in the resulting cooking type result was also considered. In the study, seven varieties with seven different meters and a total of 12 different measuring methods were compared. The key method of the thesis was sensory evaluation by descriptive method. The descriptors were used as unambiguously as possible, such as evaluating flouriness by appearance and by palpation in the mouth. In addition to sensory evaluations, experiments with structure analysis, hyperspectral imaging, and color measurement were included in the study. The purpose of the analysis was to look at the descriptor ensembles, and to observe their dimension on the axis waxy - floury and possible other independent dimensions that would diversify the description of the cooking quality. The results were examined statistically by means of generalized linear models, correlations and principal component analysis. The thesis concluded that there are some differences between European ways of determining the cooking type, and in borderline cases, different results are possible. In general, European descriptor ensembles are strongly built to support the waxy-floury axis. In addition to the descriptor ensembles, the cooking type determination include procedures and calculation methods and cannot be separated from the whole. The results of the study support the fact that hardness/softness is an independent dimension, and hardness determined by the texture analyzer clearly distinguished the varieties. In sensory comparison, external observation and mouthfeel evaluation produced similar results, except for hardness assessment. The instrumental methods distinguished the varieties more clearly than sensory evaluation. Disintegration analyzed by color measurement and starch content is a viable combination for cooking type determination.
  • Airaksinen, Kaisa (Helsingfors universitet, 2013)
    A structural problem found in pork – so-called destructured meat - complicates the production of high quality meat products. Destructured meat resembles PSE meat, although it is relatively dry compared to the watery PSE meat. Muscle fiber bundles can be peeled off in strips from destructured meat. Structural problems can already be seen in raw meat as soft texture and light colour. In addition to light colour, the pH-value of destructured meat is lower and drip loss is higher than in normal meat. In a cooked meat product this problem is seen as dry spots which are light in colour and as broken slices. The objective of this study was to improve the quality of cooked meat products. It was examined whether the quality of cooked ham improved when destructured meat was removed from the raw material before preparation of the product. In addition, it was also examined whether the mincing rate of the meat with two different grinder plates (larger, 0-plate or smaller, 20-plate) influenced the appearance of the final product. The crucial method used for whole meat products was sensory analysis. The appearance of the final ham product made of normal meat was better than that made of destructured meat. The result was the same regardless of whether a 0-plate or a 20-plate was used. The structure of the product made of pork minced with 20-plate was, however, considered superior compared to the product made of pork minced with 0- plate. The use of destructured meat as raw material in fermented sausages was also investigated – whether destructured meat could be used without weakening the quality of the final product. The ripening of fermented sausages was followed by determining the aw-value, firmness and pH-value. The study showed that fermented sausage is an excellent product to be made from structurally flawed meat. It can be concluded that the visibility of structural problems in a final product can be decreased by selecting raw material combined with a grinder plate of small size.
  • Ruohomaa, Marttaleena (Helsingin yliopisto, 2020)
    Mallasviskin valmistuksessa pääraaka-aineet ovat mallas, hiiva ja vesi. Riippuen siitä, minkä viljan mallasta ja mitä mallaslaatua käytetään, voi mallasviskin aistinvaraisissa ja kemiallisissa ominaisuuksissa olla suuriakin eroja. Tutkielmassa tutkittiin ruismaltaan alkuperämaan vaikutusta ruistisleen aistinvaraisiin ja kemiallisiin ominaisuuksiin, joita analysoitiin soveltuvin menetelmin. Ruistisleet valmistettiin belgialaisesta, kanadalaisesta ja suomalaisesta ruismaltaasta. Jokaisesta mallaslaadusta valmistettiin neljä rinnakkaisnäytettä, joiden ominaisuuksien keskiarvoja käytettiin tuloksissa ja tulosten tarkastelussa. Mallastuksen ja käymisen aikana tarkkailtiin pH:ta, brix-% -arvoja ja lämpötilan muutoksia. Käymisprosessin jälkeen tislauksissa kontrolloitiin höyrynsyöttöä, tislausnopeutta sekä tisleen alkoholipitoisuutta. Aistinvarainen arviointi toteutettiin kahdessa osassa: kolmitestillä selvitettiin eroavatko näytteet aistittavilta ominaisuuksiltaan toisistaan, jonka jälkeen koulutettu raati suoritti ruistisleille kuvailevan analyysin. Ruistisleille ominaisten kemiallisten yhdisteiden pitoisuuksia tutkittiin kaasukromatografian avulla. Kuvailevan aistinvaraisen arvioinnin sekä kaasukromatografian tuloksissa havaittiin joitakin tilastollisesti merkitseviä eroja. Asetonin tuoksussa suomalaisesta ja kanadalaisesta ruismaltaasta valmistetun ruistisleen välillä oli tilastollinen merkitsevyys, samoin kuin oljen tuoksussa belgialaisesta ja kanadalaisesta valmistetun ruistisleen välillä. Vaikka mausteen tuoksussa ja viinin maussa ei ollut tilastollisesti merkitseviä eroja, pieni p-arvo indikoi mahdollista eroavaisuutta näissä ominaisuuksissa eri maiden ruimaltaista valmistetuissa ruis-tisleissä. Kolmitestin tuloksissa tilastollisesti merkitsevää eroa ei ollut. Kaasukromatografian tuloksista tilastollisesti merkitseviä eroja löytyi propanolin, isobutanolin ja isopentanolin määrissä. Propanolin sekä isopentanolin pitoisuudet olivat tilastollisesti merkitseviä suomalaisesta ja belgialaisesta ruismaltaasta valmistettujen ruistisleiden sekä suomalaisesta ja kanadalaisesta valmistettujen ruistisleiden välillä. Isobutanolin pitoisuudet olivat tilastollisesti merkitseviä suomalaisesta ja belgialaisesta ruismaltaasta valmistettujen ruistisleiden välillä. Kaiken kaikkiaan suurimmat erot sekä aistinvaraisesti että kemiallisilta ominaisuuksiltaa olivat kanadalaisesta ja suomalaisesta ruismaltaasta valmistettujen tisleiden välillä. Ruismaltaan alkuperän lisäksi jatkossa olisi mahdollista tutkia eri mallastustapojen vaikutuksia ruistisleeseen. Lisäksi on epäselvää hävittääkö tynnyrikypsytys erot, jotka syntyvät ruistisleeseen erilaisten ruismaltaiden käytön seurauksena.
  • Sinisalo, Aurora (Helsingin yliopisto, 2019)
    Sokeri on raaka-aineena edullinen ja sitä käytetään elintarvikkeissa sen monipuolisten ominaisuuksien takia. Nykytiedon valossa liiallisesta sokerinkulutuksesta johtuva energiansaannin ylitys voi kuitenkin nostaa riskiä sairastua elintasosairauksiin, minkä takia matalampi sokerinkulutus onkin suositeltua. Ratkaisuja sokerin vähentämiseen etsitään koko ajan mm. erilaisista uusista raaka-aineista sekä prosessointitavoista. Tutkimuksen tavoitteena oli selvittää, miten sokerin vähentäminen korvaamalla sakkaroosia uudella sokerin kaltaisella tuotteella ja liukoisella kuidulla (Nutriose®) vaikuttaa tärkkelysvalumakeisen aistittavaan laatuun. Lisäksi tutkittiin tämän uuden sakkaroosin korvikkeen makeutta ja teknologisia ominaisuuksia, sekä kuidun mahdollisuuksia makeisten valmistuksessa sokerin korvaajina. Tutkimuksen ensimmäisessä vaiheessa tutkittiin sakkaroosin korvikkeen teknologisia ominaisuuksia marmeladien ja toffeen valmistuksessa. Toisessa osassa valmistettiin tärkkelysvalumakeiset, joiden aistittavaa laatua arvioitiin koulutettua raatia (N=10) ja yleistä kuvailevaa menetelmää käyttäen. Ominaisuudet, joita makeisista arvioitiin olivat: kimmoisuus, makeus, makeuden viive, karheus, sekä tarttuvuus hampaisiin. Sakkaroosin korvike liukeni hyvin veteen, mutta sakkaroosiin verrattuna huonomman liukenevuuden takia se saavutti nopeasti ylikylläisen liuoksen, jolloin se kiteytyi nopeasti säilytyksessä. Sakkaroosin korvike muodosti vähemmän viskoosisen liuoksen kuin sakkaroosi ja sillä oli lisäksi hyvät ruskistamisominaisuudet. Tutkimuksessa selvisi, että sakkaroosin korvikkeen makeus sai arvon 0,6 kun sakkaroosi saa arvon 1. Sakkaroosin osittainen korvaaminen korvikkeella makeisissa ei kuitenkaan vähentänyt tuotteen makeutta ja kimmoisuutta. Makeiset, jotka sisälsivät Nutriose® -kuitua olivat kovempia, tarttuvampia hampaisiin ja niillä oli pidempi makeuden viive kuin kontrollimakeisella. Lisäksi Nutriose -makeiset olivat vähemmän makeita, sekä karheampia kuin kontrollinäyte. Nutriose sai aikaan tärkkelysvalumakeisissa kovan rakenteen, mutta marmeladeissa pektiinin kanssa sen rakenne oli pehmeämpi ja venyvämpi.
  • Uusihonko, Jenni (Helsingin yliopisto, 2020)
    In UHT-heating (Ultra High Temperature) product is heated above 130 degrees for a few seconds, which destroys all micro-organisms and prolongs shelf life of the product. UHT-heating is divided into direct and indirect heating. The aim of this study was to compare the effects of direct and indirect UHT-heating on the composition and quality of skimmed milk. The properties were also examined with a protein drink, but to a lesser extent. Differences between indirect and direct UHT-heating and off-flavours formed from proteins were examined by sensory evaluations and proteins in the samples were examined by SDS-polyacrylamide gel electrophoresis method (SDS-PAGE), which separates proteins according to their size. Sensory evaluations and electrophoresis analyzes were organized after production and during storage at regular intervals until best before date, storing samples at different storage temperatures. In sensory evaluations the differences between direct and indirect UHT-heating were relatively small from the production to best before date, but mainly direct UHT-heated milks received better or as good evaluation results as indirect UHT-heated milks. Milks stored in cold temperature received better evaluation results than those stored in warm temperature, and storage temperature had a greater effect on milk evaluation results than UHT-heating. Changes (reddish colour, caramel taste) caused by Maillard reaction were observed in both UHT-heated milks after one month of warm storage. In electrophoresis analyzes the protein bands of direct and indirect UHT-heated milks differed immediately after production and during storage. After production protein bands of milks heated by direct UHT-heating method corresponded more to the protein bands of raw milk. The intensity of protein bands decreased how longer and how warmer temperature the milk samples were stored. Whey proteins β-lactoglobulin and α-lactalbumin were visible in milks heated by direct UHT-heating method, but not indirect, while casein protein bands (αs1-casein and β-casein) were intensively visible in electrophoresis analyzes of both heating methods, as well as large protein aggregates (molecular size over 250 kDa) at top of the gel.
  • Liljeroos, Anna (Helsingin yliopisto, 2020)
    Beer is the world´s most popular alcohol drink, with a long history. It is commonly made with baker’s yeast Saccharomyces cerevisiae. Yeast used for fermentation has an effect on the sensory properties of the product. Saccharomyces boulardii is a probiotic yeast. The objective of the thesis was to explore the use of probiotic yeast S. boulardii in wheat beer and develop it further with the help of sensory evaluations. S. boulardii is used to prevent travelers' diarrhea and as a help to many intestinal disorders. The use of probiotic yeast could make a new interesting product with functional properties. In the experimental part of the study beer was produced with two yeasts, S. cerevisieae and S. boulardii. The beer was matured in two different temperatures (20°C and 37°C). The four samples were compared to commercial reference product. One sample (C37) did not meet quality standards so it was left from sensory analysis. The sensory analysis was performed with 9 trained panelists by using generic descriptive analysis. Concentration for alcohol was measured with High Performance Liquid Chromatography (HPLC). Also pH value and the colour shade was measured. The samples were plated on agar plates to calculate colonies forming units (CFU) to test the yeast surviving in 1, 2 and 3 months time. Eight attributes were rated using visual analogue scales, anchored verbally at the end points. Sensory evaluation showed that the beer differed statistically significantly from each other in three attributes: appearance of foam, the mouthfeel of carbon dioxide and stale, musty smell. B37 was categorized in the same group in Tukey’s test with commercial product although the alc. vol.% was lower. The samples that were fermented in the room temperature had a musty smell and they had darker colour. pH values had only minor differences and the sourness did not have statistically significant differences in sensory analysis. Yeasty taste did not vary significantly between samples. B37 maintained colonies forming units better in the first month and B20 in the second and third measurement. B37 was the most similar to the commercial product, so further studies are encouraged to assess right fermentation conditions. The survival of the probiotic yeast was good, so the product has potential to the beer market.
  • Tenhovirta, Santeri (Helsingin yliopisto, 2019)
    In the thesis, the effects of six different lactic acid bacteria (LAB) species on properties of sour beer was studied. As the fermentation by LAB may yield unexpected results, and as the prediction of specific organoleptic compounds present in LAB-fermented sour beers has proven to be challenging, sensory and chemical properties of sour beers fermented with selected LAB was assessed. The main research question was “are there statistically significant differences between the different sensory properties of the sour beers produced with different LAB species?”. Use of Lactobacillus plantarum, L. rhamnosus, L. brevis, L. buchneri, L. delbrueckii and previ-ously unreported in sour beer brewing, L. alimentarius, was assessed. Fermentation was carried over approximately six weeks, during which the changes in viable cell density, pH, refractive index, organic acid and ethanol (using PDA/RI) and sugar compositions (using HPAEC-PAD) were assessed. Sensory evaluation was performed in two parts: Overall preference rank test with untrained panellists and descriptive analysis with trained panellists. Differences were found in the results of viable cell count, organic acid composition and descriptive sensory analysis. Increase in lactic, acetic and succinic acid and ethanol over the fermentation period was detected. Decrease in citric acid, maltose, glucose and sucrose was detected. Novel L. alimentarius yielded fastest growth rate, with encouraging results from sensory analysis. L. delbrueckii did not grow in the substrate media, allowing possible infection to take place. L. brevis and L. buchneri yielded acetic acid concentrations detectable in sensory and chemical analysis. Increased lactic acid concentration was associated with increased overall rank, raspberry aroma and apple and vinous flavours, with negative correlation to butyric, rancid and yeasty flavours and bitter aftertaste. Further studies are suggested to assess the effects of fermentation temperature, O2 availability, wort composition and buffering capacity on the results of the LAB fermentations.
  • Oksa, Vilma (Helsingin yliopisto, 2019)
    Abstract Licorice is traditionally made from sugar, molasses, water, wheat flour, and licorice extract. In the literature review, the focus was on the properties of quinoa, licorice extrusion, sensory and physical properties of licorice and the basis behind sensory evaluation and instrumental testing in product development. In the experimental part, gluten-free quinoa and rice licorice were made and their properties were studied with multiple sensory and instrumental measurements, and the self-made samples were also compared to commercial samples to see the possible differences between them. The hypothesis was that the changes in the recipes and process parameters would result in significant differences between the products. The sensory evaluations included a generic descriptive analysis with the first batch and two separate consumer tests with the two batches. The instrumental testing conducted of compression and extension tests with Instron and the determination of water activity. The data were analyzed with one- and three-way analyses of variance, as well as principal component analysis for the descriptive analysis. The manufacturing of the quinoa and rice licorice with the twin-screw extrusion was achieved. The generic descriptive analysis revealed that all the self-made samples were described similarly to each other, while the commercial gluten-free samples differed significantly from these. The quinoa licorice was seen sticky and not homogenous in appearance or texture, while the commercial samples were described as more homogenous and more intense in their taste. The consumer tests showed that both panels preferred the commercial samples over the self-made ones and that the quinoa licorice was preferred over the rice licorice. Commercial samples were seen as soft and chewy, while all the self-made samples from both tests were described as hard and grainy. The hypothesis was overruled since the quinoa licorice samples did not have significantly different properties despite the variation in the process parameters and ingredients. The study revealed that at least with these parameters there are no noticeable, significant differences in the sensory or physical properties of quinoa licorice. The commercial samples, however, remain significantly different from the self-made samples.