Browsing by Subject "fermentointi"
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(2012)Folate is a water-soluble vitamin that belongs to the vitamin B group. The most important function of folate is to participate in C1 metabolism, and folate deficiency can lead to megaloblastic anaemia, neural-tube defects or coronary diseases. In Finland the folate fortification of food products is not mandatory and the intake of folate is still too low. Based on previous studies, blue lupin (Lupinus angustifolius) seems to be a good source of folate, especially the Haags Blaue variety, which has shown to be suitable for cultivation under Finnish environmental conditions. The aim of this research was to study if the folate concentration of blue lupin could be increased with germination and fermentation. In addition, the purpose was to examine how these bioprocessing methods would affect vitamer distribution of folates. Three germination experiments were performed, two with seeds that were soaked overnight in water and one with seeds that were soaked in lactic acid solution. The duration was four or five days and the samples were collected daily. The fermentation experiment was performed with kernel flour from non-germinated seeds and kernel flour from seeds that were germinated for two days. The synthesis of folate was studied using two microbes: Streptococcus thermophilus and Saccharomyces cerevisiae. The fermentation with S. cerevisiae yeast was made both with and without glucose addition. Samples were taken at 0 and 24 h. Total folate concentrations of samples were analysed with a microbiological method and the vitamers were analysed with an ultra-high-performance liquid chromatography method (UPLC). The folate concentration of seeds increased 2-fold by germination. The proportion of 5-methyltetrahydrofolate increased significantly during germination, from 60 % in nongerminated kernel flour to 77–88 % in germinated dehulled seeds. S. thermophilus did not produce folates in lupin flours. The folate content of non-germinated flour was increased 1.8-fold by yeast fermentation between 0 and 24 h, and yeast needed the glucose addition. However, glucose addition did not have an impact on folate concentrations of kernel flour from germinated seeds. Germination significantly increased the folate content of lupin seeds, and the greatest proportion of folates were stable vitamers. Stability of vitamers is important for the folates of food products thus germination of lupin seeds appears to be an interesting processing method. On the basis of the fermentation experiment, S. cerevisiae is a promising folate producing microbe when using lupin flour as a matrix. The fermentation experiment should still be repeated and performed using sterilised flour so that the actual production of folate by S. cerevisiae could be studied.
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(2019)Partial replacement of wheat flour with faba bean flour enhances the nutritional quality of wheat bread, but simultaneously weakens the gluten network, decreases the bread volume and increases bread hardness. The flour can be fermented with lactic acid bacteria, capable of producing exopolysaccharides (EPS), to improve the technological properties for baking. The aim of the research was to produce a bread rich in protein by replacing 30 % of the wheat flour with faba bean flour, which was fermented by EPS-producing Weissella confusa or Leuconostoc pseudomesenteroides -lactic acid bacteria to improve the baking quality. The effect of native and fermented faba bean flour to the properties of dough and bread was studied. Water absorption and rheology of the dough was analyzed with farinograph and Kieffer test of Texture Analyser. The volume of the breads was measured by rapeseed replacement method, and the texture of the breads by using TPA-test of Texture Analyser. The protein content of the total energy value of the bread was determined by calculations. As expected, native faba bean flour decreased the stability and elasticity of the dough compared to the 100 % wheat dough. The volume of wheat - faba bean bread decreased 11 % and the crumb texture was 38 % harder compared to the wheat bread. Fermentation of faba bean flour increased the water absorption and decreased the extensibility of the dough compared to the dough with native faba bean. Fermentation with W. confusa increased the bread volume by 21 % and decreased the bread hardness by 12 % compared to the breads with native faba bean. The volume of the breads with W. confusa-fermented faba bean was increased by 8 % even compared to the 100 % wheat bread. Yet the breads fermented with L. pseudomesenteroides had considerably decreased volume (-15 %) and increased hardness (+116 %) compared to the breads with native faba bean. The difference was hypothesized being caused by more intense acidification and possibly the different structure and amount of EPS. In this study 30 % of wheat flour was successfully replaced with faba bean, resulting a bread rich in protein and with a texture similar to 100 % wheat bread, as the faba bean flour was fermented with EPS-producing W. confusa -lactic acid bacteria. New methods for analyzing the rheology of EPS-containing dough would be beneficial for estimating the baking quality.
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(2015)The aim of the study was to optimize growth media and its composition for one Lactobacillus strain. The purposes of the optimized culture media for fermentation were to maximize cell count and amount of viable cells during processing. The raw materials for growth media had to be suitable for industrial use. The study was performed by Bioscreen and fermentation tests in different growth media. At first ability of the strain to grow was tested by Bioscreen C with different raw materials and their compositions. According to literature, six carbon, four nitrogen sources and three other raw material were chosen to Bioscreen tests. Bioscreen C measured turbidity (OD value) of cultivation. According to the results from Bioscreen tests, optimal raw materials were chosen to the fermentation tests. The optimal carbon sources were whey permeate powder and glucose, the optimal nitrogen sources casein peptone and yeast extract and other raw materials manganesulfate, magnesiumsulfate and yeast extract. The cultivations were made in a bioreactor (Biostat Q). The starter strains were concentrated and freeze-dried. Samples from cultivated, concentrated and freeze-dried starter strain were analyzed (cell counts, optical density, growth rate, base consumption and survival-%). Results were compared to those obtained using control medium that is known to support the growth of the Lactobacillus strain. Lactobacillus strain was able to grow in different growth media. In Bioscreen tests compositions of growth media have major effect on lactobacilli growth. Bioscreen experiments revealed that in most cases the Lactobacillus strain grew to higher OD values in the composed media compared to control medium. In Bioscreen tests the sugar based growth media required more added minerals and yeast extract than whey permeate based media. Yeast extract was found to promote Lactobacillus growth in Bioscreen tests. In fermentation tests cells grew on growth media equally as on control media. Suitable alternative options for growth media were found from tests for further studies. Further studies can research functionality of the raw materials in production scale and preservation of the cell concentration during storage.
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(2016)Tutkielman kirjallisuuskatsauksessa perehdyttiin kauraan ja härkäpapuun raaka-aineena. Lisäksi tutustuttiin intialaiseen riisistä ja mustasta linssistä fermentoinnin avulla valmistettuun idli-höyryleipään ja sen valmistusprosessiin. Tutkielman kokeellisen osan tavoitteena oli selvittää soveltuvatko kotimaiset kaura ja härkäpapu idlin valmistusprosessiin. Idlin raaka-aineet korvattiin osittain tai kokonaan kauralla ja härkäpavulla. Lisäksi tutkittiin heräteviljelmän käyttöä taikinan ja valmiin höyryleivän ominaisuuksien kannalta. Osa taikinoista fermentoitiin idlin valmistusprosessin mukaan spontaanisti ja osaan lisättiin startteriksi leivinhiivaa tai viiliä. Taikinoiden viskositeetit mitattiin ennen fermentointia. Fermentoitumista mitattiin taikinan tilavuuden muutoksen, pH:n ja happoluvun avulla. Höyryleivistä määritettiin paistohäviö, korkeus ja sisuksen kovuus heti sekä seitsemän vuorokauden säilytyksen jälkeen. Valmiiden höyryleipien ravintosisältö ja välttämättömien aminohappojen koostumus laskettiin perustuen kirjallisuusarvoihin. Härkäpapu-riisi- ja härkäpapu-kaura -taikinat fermentoituivat spontaanisti. Härkäpapu-riisi -taikina fermentoitui härkäpapu-kaura -taikinaa tehokkaammin. Härkäpapupitoisuus nosti molempien taikinoiden happolukua fermentoinnissa. Taikinaan lisättävällä viilillä tai leivinhiivalla voitiin säädellä taikinan tilavuutta, ja sitä kautta vaikuttaa höyryleivän tilavuuteen, huokoisuuteen ja kovuuteen. Härkäpavusta ja riisistä oli mahdollista valmistaa rakenteeltaan hyvä höyryleipä. Härkäpapu ja kaura tuottivat ominaisuuksiltaan erilaisen, rakenteeltaan ei-huokoisen ja tiiviin höyryleivän. Kauraa sisältävät höyryleivät säilyivät pehmeämpänä kuin riisiä sisältävät. Raaka-aineiden suhdetta muuttamalla saatiin aikaan erilaisia höyryleivän rakenteita höyryleivän proteiinilaatua heikentämättä. Lähes kaikki höyryleivät ylittivät FAO:n asettamat vertailuarvot välttämättömien aminohappojen määrissä. Idli-prosessilla fermentoidut kaura ja härkäpapu soveltuvat höyryleivän lisäksi myös muiden ravintoarvoiltaan laadukkaiden ruokavalmisteiden pohjaksi.
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(2022)Plant-based proteins are gaining increasing interest among the scientists and consumers due to accelerating health and environmental awareness. Fermentation is a traditional method for improving the shelf-life, nutritional profile and sensory attributes of food. The aim of the Master’s thesis was to investigate the impact of semi-solid fermentation with Pleurotus ostreatus mycelium on faba bean (Vicia faba) and oat (Avena sativa) protein. 16 amino acids were analyzed by UHPLC-PDA -method, and the nutritional value of protein was estimated by calculating Amino Acid Score (AAS) for essential amino acids. The results indicate that the presence of fungus decreased the total protein content of faba bean from 33 % to 27 % while the protein content of other samples remained stable. Significant changes were observed in the amino acid compositions, but the changes were not consistent. Only the content of alanine and valine increased in all three fermented samples. AAS -method showed an increase in the content of some limiting amino acids. Overall, the fermentation with Pleurotus ostreatus seemed to have a slightly positive or neutral impact on the essential amino acid composition of faba bean and oat protein.
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(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.
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(2022)Lähes miljardi ihmistä maapallolla elää kroonisesti aliravittuna, ja samaan aikaan ruokaa päätyy jätteeksi noin kolmasosa tuotetusta määrästä. Tätä hävikkiä on mahdollista vähentää käyttämällä ruokajätteeksi luokitellun ruuan raaka-aineena valmistettaessa uutta ruokaa. Tämän tutkimuksen tavoitteena oli kehittää valituilla maitohappobakteerikannoilla optimoitu leipomosivuvirtojen kierrätysmenetelmä, jonka avulla korvataan apu- ja säilöntäaineita leivontaprosessissa. Työssä ratkottiin prosessin ongelmia nostettaessa tuotantoa pilot-mittakaavasta leipomomittakaavaan. Valitun propionihappobakteerikannan (PAB) tuottamalla propionihapolla voidaan estää mikrobien aiheuttamaa leivän pilaantumista ja näin ollen pidentää sen säilyvyyttä. Toinen valittu bakteerikanta tuotti eksopolysakkarideja (EPS), joilla voidaan mm. nostaa taikinan viskositeettia ja lisätä valmiin leivän tilavuutta sekä pidentää säilyvyyttä. Tutkimus toteutettiin vertailemalla pilot-mittakaavan prosessia leipomomittakaavan prosessiin erikseen molemmilla maitohappobakteereilla fermentoidulla ylijäämäleivällä. Fermentointiprosessi suoritettiin Viikissä elintarvike- ja ravitsemustieteiden osaston prosessilaboratoriossa ja leipomomittakaavan leivonnat Koivulan leipomossa Kouvolassa. Leivistä otettiin näytteitä, jotka analysoitiin instrumentaalisesti ja aistinvaraisesti. PAB-leipäraskin vaikutus leivän säilyvyyden parantumiseen oli selvästi havaittavissa homehtumiskokeissa. Nämä suotuisat vaikutukset pystyttiin säilyttämään siirryttäessä laboratoriosta tuotantoympäristöön. Sen lisäksi PAB-pilot- ja -leipomoleipien happamuusarvot olivat hyvin lähellä toisiaan, mikä tukee mittakaavan muutoksen onnistumista. Siirryttäessä laboratoriosta tuotantoympäristöön EPS-leivillä ei tuntunut olevan eroa leivän ominaisuuksissa lukuun ottamatta leipomossa tehdyn EPS-leivän pienempää tilavuutta ja suurempaa kovuutta. Testattu takaisinfermentointi ei onnistunut leipomo-olosuhteissa, mutta sen jatkokehittämiseen saatiin arvokasta tietoa.
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(2012)The literature review focused on the proteins and insoluble fibre, ?-(1->4)-galactan, of blue lupin seed and how they degrade during germination. The review also dealt with the food applications of lupins and the harmful substances of lupins: allergens and ?-galactosides. The object of the experimental study was to determine the peptidase activities in the blue lupin seeds at the different stages of germination, classify the peptidases in the seeds and investigate the changes occuring in the proteins during germination and fermentation. The percentage of the water-soluble protein in the seeds was also determined. Blue lupin seeds were soaked in water over night and were germinated in the dark (15 ° C, RH 100 %). Peptidase activities were determined spectrofotometrically using azo-casein as a substrate. Class-specific peptidase-inhibitors (Pepstatin A, PMSF, E-64 and O-FEN) were used for classification of peptidases. Lactobacillus brevis and Lactobacillus rhamnosus were used in the fermentations (35 °C, 24 h) as well as baking yeast. The changes which occured in the proteins during germination and fermentation were investigated by electrophoresis (SDS-PAGE). The Dumas method was used to determine the percentage of the water-soluble protein in the extracts composed of soaked and germinated (2 day) seeds. Peptidase activities increased until the second day of germination and then remained constant until the fourth day. Serine- and aspartic peptidases were identified by inhibitor tests but not cysteine peptidases, even though cysteine peptidases have been previously known to break down legume proteins during germination. The cysteine peptidase inhibitor, E-64, used in this study has been observed earlier to inhibit cysteine peptidases belonging to papain family but not to legumain family. Proteins degraded slightly when the germination continued 4 days, and the degradation continued further during the fermentations. Large polypeptides (MW 45–100 kDa) mainly degraded during germination and fermentation. In addition, 17 kDa polypeptides degraded during fermentation. Possible 20 kDa hydrolysis products also formed during fermentation. The degradation of proteins in fermentations was more efficient when seeds germinated for 2 days were used compared to ungerminated seeds. The content of the water-soluble protein in the soaked seeds and the seeds germinated for 2 days varied between 35–96 %, and the content increased markedly when the pH of the extraction solvent increased from 6 to between 7.5–9.0. Thus the alkalinity of the extraction solution changed the structure of the storage seed proteins to more water-soluble form. The peptidase activity of germinated blue lupin could be applied in varied fermentation processes. The storage proteins of blue lupin were extremely water-soluble, so this discovery could be utilised for manufacturing substitutes for dairy products.
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