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Browsing by Subject "faba bean"

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  • Suryanarayanan, Tilak (2015)
    The objective of the thesis was to investigate the effect of carbohydrates on solubility, emulsifying, gelling and water holding properties of proteins. Faba bean is a readily available pulse crop with high protein content similar to soy bean and there is a lot of potential for a novel, high protein fermented gel product to be made from a pulse crop like faba bean. This is mainly due to its remarkable nutritional properties, functional properties and low cost, the demand for faba bean protein ingredients will grow. The current study was an attempt to develop pulse protein based products – emulsion (milk-like) and emulsion gel (yogurt-like) from faba bean. It seeks to expand the field of application of faba bean protein based products. Faba bean was pretreated, dehulled and milled. The flour was made into suspensions and the starch in faba bean was subjected to amylolytic treatments (addition of alpha amylase and glucoamylase) to breakdown the starch into smaller particles. These treated suspensions were then homogenized to obtain emulsion. A protein based gel network was produced with the gelation of amylolytically treated faba bean proteins. The emulsion properties, specifically droplet size, stability and activity were tested by PAMAS Particle Counter System. Light microscopy was applied to reveal the microstructure of emulsion and emulsion gel. Emulsion gel texture properties were studied by texture analysis. The emulsions were relatively stable over a period of a month and had white ‘milk’ like appearance. The emulsion gels prepared (amylolytic treatment) had slightly higher water holding capacities than the control A (entire starch present) and control B (starch removed by filtration) emulsion gels. Texture analysis of the emulsion gels showed that more force was required by probe to penetrate the yogurt produced from amylolytically treated samples and less force was required to penetrate the yogurt produced from controls A and B. The yield of the emulsion gels were higher for the amylolytically treated samples. It can be concluded that amylolytic treatment has increased the water holding capacity and also resulted in stronger gel systems.
  • Tang, Jingsi (2017)
    The literature review illustrated the negative impacts of mold spoilage in baked goods and the significance of lactic acid fermentation used to prevent mold growth, with a special emphasis on the mechanism of antifungal metabolites produced by lactic acid bacteria. A brief introduction of the raw materials (faba bean and pearl millet) was also involved. The aim of this study is to explore the potential of different strains of lactic acid bacteria producing antifungal compounds during faba bean and pearl millet fermentation, to facilitate their application in baked foods with extended shelf-life. Different species of lactic acid bacteria isolated from faba bean and pearl millet in previous studies were used singly as a starter for sourdough fermentation. Antifungal assays were carried out on target molds and selected sourdoughs showing antifungal activity were analyzed to assess the nature of antifungal compounds (e.g. organic acids and proteinaceous compounds). All of the water-soluble extracts from sourdoughs were able to inhibit the growth of the indicator molds P. paneum and P. albocoremium, but not A. niger. This was in agreement with previous findings, showing that sensibility towards different antifungal compounds is not identical across different molds. The concentration of organic acids and the potential proteinaceous nature of the most active extracts was also established. It was hypothesized that the organic acids produced during fermentation can act in synergy with proteinaceous compounds and could contribute to the antifungal activity of faba bean sourdough fermented with L. sakei F1410 and L. mesenteroides I21 and of pearl millet sourdoughs fermented with P. pentosaceus A133 and A1231. Furthermore, small molecular peptides generated possibly through proteolysis of proteins in faba bean sourdough fermented with P. pentosaceus I02 and in pearl millet sourdough fermented with L. palantarum A103 could be responsible for the antifungal effect.
  • Karhu, Simo (2024)
    The primary objective of this thesis was to observe the effect of fermentation of oat and faba bean flour mixture on oat β-glucan. The secondary objective was to define how fermentation conditions affect β-glucan content, pH, total titratable acidity (TTA) and viscosity in oat-faba bean matrix utilizing experimental design and response surface methodology (RSM). As fermentation is a part of manufacturing process of plant-based yoghurt alternatives, this thesis observed the fermentation process in detail to define its effect on β-glucan. The flour mixture consisted of whole grain oat flour, oat bran concentrate, faba bean flour, faba bean protein isolate and water. This mixture was fermented with a commercial yoghurt starter, consisting of Bifidobacterium sbsp., Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus paracasei and Streptococcus thermophilus species. Studied fermentation condition factors were time (7 h, 12.5 h, 18 h), temperature (30 °C, 37.5 °C, 45 °C) and inoculum ratio (0.01 %, 0.1 %, 1% w/w). The relationship between the factors and responses were analyzed with the Central Composite Face-centered (CCF) design and response surface modelling. In all tested fermentation conditions, no significant decrease in β-glucan content was observed. However, relationships between fermentation condition factors and other responses were obtained. All factors had decreasing effect on pH and increasing effect on TTA. All factors contributed to viscosity, but temperature was significantly more effective than others, having positive, non-linear effect.
  • Astola, Anni (2020)
    Faba bean (Vicia faba L.) is a healthy and ecological pulse crop. Nevertheless, it contains antinutritive compounds, including lectins. Lectins are proteins or glycoproteins that bind to carbohydrates. Faba bean lectin is called favin and it binds specifically to mannose- and glucose-like carbohydrates. Agglutinatination assays have been traditionally used for the determination of lectins. These assays are, however, often inaccurate. The aim of this study was to adapt and optimize a method for the quantification of faba bean lectin and analyze lectin levels in untreated and treated faba beans. Enzyme-Linked Lectin Assay (ELLA), which is based on the ability of lectins to bind to specific carbohydrates, was adapted in the study. The hypothesis was that the method is suitable for the quantification of faba bean lectin. The commercial lectin standard did not react in the assay and thus the quantification of lectins was not possible. The faba bean samples, however, reacted and the absorbance values of varying samples were compared. The protein-rich faba bean fractions gave the highest absorbance values. Particle size affected the determination of lectins. Heating was efficient in lowering the absorbance values. Long-time roasting and boiling were the most efficient methods to reduce the binding capability of lectins.
  • Turkki, Tuomas (2020)
    Constant increase in protein consumption is global trend and can be seen in consumer behavior of Finnish markets. Consumers are interested in replacing meat proteins with plant proteins, and therefore, it is important to develop locally grown-domestic products and invest in local crop research. Due to this, the current study focuses on the domestic vegetable protein (faba bean and oat) texturing by extrusion cooking and on their functionality when included in burgers. The literature section presents an overview of previous studies on extrusion of vegetable proteins and the functionality of textured vegetable proteins (TVP). In the experimental work the research materials were faba bean protein concentrate and oat concentrate with high β-glucan content. The flour concentrates were texturized with high-moisture extrusion, in different mixtures. Mixtures were prepared in the ratio of: 3:1 (FO) and 1:3 (OF) and soy protein concentrate (S) was used as a reference sample. Moisture content and water absorption capability of TVP samples were measured instrumentally. TVPs were later on applied to develop burgers based on a mixture of meat and vegetable sources. Burgers were prepared for instrumental analysis with seven different recipes, where TVP inclusion, water addition and meat content varied. TVP was included in three different percentages: 0, 25 and 50% and water was added in 0, 12.5 and 25%. In relation to TVP inclusion and water addition, the meat content varied between 25-100%. Sample with 100% meat was used as control sample (0-sample) and burgers with S inclusion as reference samples. Samples were analyzed for cooking loss, shear force and texture profile (hardness, fracturability, springi-ness, cohesiveness, gumminess, chewiness and resilience) which was measured with a compression method. Based on the results of the instrumental analysis, five different burger samples were selected and evaluated for sensorial properties (chewiness, biting force, juiciness and pasty mouthfeel). The highest TVP moisture content was in OF and lowest in FO, hence the difference between S and FO was not significant. The highest water absorption was in S and lowest in OF. 25% TVP inclusion in burgers reduced the cooking loss (p<0.05) and 50% inclusion reduced it even more (p<0.05). With 25% TVP inclusion S had higher (p<0.05) cooking loss compared to FO and OF. With 50% TVP inclusion the difference was eliminated. Water addition increased cooking loss significantly (p<0.05) with each type of TVP. The FO and OF inclusion showed to weaken (p<0.05) the textural properties of burgers and reduced (p<0.05) the shear force. The reference sample S was found to maintain the structure similar as from the meat control sample. Water addition, while replacing meat, weakened also the textural properties and shear force in each TVP included sample. Based on the results, the inclusion of FO and OF in burgers reduces the cooking loss compared to the 0-sample and the reference sample S. The texture of burgers became weaker with FO and OF inclusion, however sensory evaluation revealed them to be similar to S included sample. Therefore additional studies focusing on improving the textural properties of these TVPs are needed. Faba bean and oat concentrates with higher protein contents could be needed to obtain a texture closer to meat.
  • Oksanen, Anni (2021)
    The consumption of meat will be growing in the near future. However, meat production is unsustainable and uses great amounts of environmental resources. Meat consumption could be reduced by usage of meat analogues that are foods or food ingredients that are mostly made of plant proteins and their mouthfeel, texture, nutritional value and visual appearance resemble meat. Faba bean (Vicia faba L.) is a potential raw material for meat analogues although not widely studied. At the moment the most established method for production of meat analogues is wet extrusion (also called high moisture extrusion). The objective of the present work was to produce plant based extrudates with fibrous structure through wet extrusion of faba bean protein concentrate and isolate and study the effect of various processing parameters on the structure of the extrudates. Wet extrusion of faba bean protein fractions is not widely studied, so there was need for this study. Experiments were carried out using split-plot Box-Behnken design, where the variables were faba bean protein isolate content (30, 50 and 70%), water content of the mass (60, 62.5 and 65%) and temperature of the long cooling die (40, 60 and 80 ℃). The response variables were pressure at the die and torque, hardness, gumminess, springiness, chewiness, color, water and oil absorption capacities, water hydration capacity and cutting strength of the extrudate. The results were analyzed using regression analysis. Extrudates were produced successfully in all the experiments, and they had fibrous structure to some extent. The content of protein isolate had significant effect on torque, hardness, gumminess, chewiness, cutting strength, water absorption capacity and lightness. Water content of the mass had also significant effects on torque, hardness, gumminess, chewiness, cutting strength, water absorption capacity and lightness, although the effect was mostly smaller than isolate contents. The temperature of long cooling die had effect only on perpendicular cutting strength and water absorption capacity and the effects were very small. This study showed that producing fibrous plant based extrudates through wet extrusion is possible using faba bean protein isolate and concentrate. The best structures of extrudates were obtained with 30–50% isolate content. Water content didn’t have as clear optimum values as isolate content, but samples with soft and good fibrous structure were obtained at water content of 62.5–65%. In the future the effects of extruder barrel temperature or addition of some other ingredient on the structure of extrudates could be investigated. Faba bean proteins are a potential raw material for plant based extrudates.
  • Sahra, Mia (2019)
    Kivennäis- ja hivenaineet ovat lypsylehmälle välttämättömiä elintoimintojen ja tuotannon ylläpitoon. Härkäpavun siementä voidaan käyttää valkuaisen lähteenä ja koko kasvustoa säilörehuna, mutta niiden hivenainekoostumusta ei tunneta yhtä hyvin kuin rypsirouheen ja nurmisäilörehun. Tutkimuksessa verrattiin lypsylehmän kivennäis- ja hivenaineiden saantia ja sulavuutta härkäpapusäilörehusta ja härkäpavun siemenestä nurmisäilörehuun ja rypsirouheeseen. Tutkielmassa tarkasteltiin kahta koetta, jotka oli tehty Viikin opetus- ja tutkimustilalla vuosina 2014 ja 2015. Molemmissa kokeissa oli 8 Ayrshire-rotuista lypsylehmää. Kokeet toteutettiin kaksinkertaisina 4x4 latinalaisina neliöinä, joissa oli neljä ruokintaa neljänä kolmen viikon jaksona. Koeasetelmat olivat 2x2 faktoriaalisia. Ensimmäisessä kokeessa faktoreina olivat säilörehun kasvilaji (nurmi tai 1:1 nurmi+härkäpapu-kevätvehnä) ja väkirehun raakavalkuaispitoisuus (175 tai 200 g/kg ka). Toisessa kokeessa faktoreina olivat valkuaistäydennys eri lähteistä (rypsirouhe tai härkäpapu), sekä näiden osittainen korvaaminen Spirulina platensis mikrolevällä. Kokeen 2 koeruokinnat olivat isonitrogeenisiä valkuaisrehujen suhteen. Kokeessa 2 kaikissa koeruokinnoissa oli sama pitoisuus kaupallista kivennäisrehua ja kokeessa 1 kivennäislisä oli täysrehuissa. Härkäpapusäilörehuseos sisälsi enemmän kivennäisaineita, mutta vähemmän hivenaineita kuin nurmisäilörehu. Härkäpavun siemen sisälsi 70 % enemmän kuparia kuin rypsirouhe. Härkäpapusäilörehuseos lisäsi eri kivennäisaineiden saantia 1-6 %, mutta vähensi hivenaineiden, kuten raudan ja mangaanin saantia 5-7 % verrattuna nurmisäilörehuun. Härkäpavun siemen lisäsi kuparin saantia 9 %, mutta pienensi magnesiumin, rikin, raudan, mangaanin ja seleenin saanteja 2-14 % verrattuna rypsirouheeseen. Härkäpavun lisääminen ruokintaan kokoviljasäilörehuna tai kokonaisena siemenenä ei vaikuttanut kivennäis- tai hivenaineiden sulavuuteen. Härkäpapusäilörehu tai härkäpavun siemen eivät eronneet merkittävästi nurmirehusta tai rypsistä hivenaineiden lähteinä. Härkäpapu ei sisältänyt mitään kivennäis- tai hivenainetta haitallisen suurta tai hälyttävän pientä määrää.
  • Tauriainen, Vappu (2020)
    Faba bean (Vicia faba) has potential as a domestic supplemental protein feed, as its seeds are rich in crude protein and starch. However, faba bean protein is low in methionine and highly degradable in the rumen, which reduces its nutritional value. The rate of protein degradation can potentially be decreased by industrial heat and steam treatment. The aim of the study was to investigate how feed industrial processing and methionine supplementation can affect the milk yield and milk composition of dairy cows. The study was conducted at the research farm of the University of Helsinki in Viikki from 6.1.2018 to 21.4.2018. Five multiparous Finnish Ayrshire cows with ruminal fistulas participated in the study, which utilized a 5x5 Latin square study design with three-week trial periods. The five experimental treatments consisted of the following isonitrogenous protein feeds: rapeseed meal (RR), milled faba bean (HJ), roasted (industrial heat treatment) faba bean (HR) and methionine-supplemented (15 g/day omasal infusion) faba bean feeds HJM and HRM. The cows were fed TMR (total mixed ratio) ad libitum. TMR was based on first cut timothy and meadow fescue grass silage (D-value 706 g/kg dry matter), including a mixture of barley-oats, sugar beet pulp and a mineral supplement. The share of concentrate in the dry matter of TMR was 38 %. Faba bean feedings (HJ, HJM, HR, HRM) increased dry matter intake by an average of 1.6 kg/day compared to rapeseed feeding, but this had no effect on milk yield, which averaged 27.7 kg/day in the experiment. Crude protein and starch intakes were higher in faba bean feedings compared to rapeseed feeding. Rapeseed meal contained more fat than milled and roasted faba beans, which increased total fat intake in rapeseed feeding. Faba bean feedings increased the digestibility of crude protein and the protein content of milk compared to rapeseed feeding. Roasting of faba beans tended to increase milk and lactose yields (HJ, HJM vs. HR, HRM). However, methionine supplementation had no effect on milk or protein yield (HJ, HR vs. HJM, HRM). Faba bean feedings increased the content of saturated de novo fatty acids in milk fat and decreased the content of long-chain mono- and polyunsaturated fatty acids compared to rapeseed feeding. Feeding had little effect on rumen fermentation or plasma energy metabolites. According to this study, faba beans were palatable as a supplementary protein feed and it was possible to replace rapeseed meal by milled or roasted faba beans without a decrease in total dry matter intake or milk yield. Roasting of faba bean tended to increase milk yield compared to milled faba bean. Faba bean feeds increased the content of saturated de novo fatty acids and reduced the content of unsaturated fatty acids. Methionine supplementation had no effect on milk production in this study.
  • Anttila, Anne (2014)
    The aim of this study was to investigate dairy cow performance on faba bean compared to rapeseed meal on silage based diets. Increasing use of grain legumes may improve selfsufficiency of feed protein. The study was conducted at the research farm of University of Helsinki. In the experiment, eight multiparous Finnish Ayrshire cows were used. Four of them were fitted with rumen fistula. In the beginning of the experiment, cows were 100 (± 51) days in milk. Replicated 4x4 Latin square design was used: the other square consisted of cows with rumen fistulas and the other of intact cows. Treatments of the study were concentrate feeds as follows: control (no protein supplement), rapeseed meal, faba bean and mixture of rapeseed meal and faba bean. Concentrates were fed at a rate of 14 kg/d and silage was given ad libitum. Concentrate feeds including protein supplement were isonitrogenous crude protein content being approximately 200 g/kg DM. Protein supplementation increased silage intake (2,4 kg/d) and milk production (1,6 – 4,9 kg/d). Protein supplementation decreased milk fat content (41,2 vs. 45,3 g/kg DM) but increased milk protein content (35,5 vs. 34,3 g/kg). Feed nitrogen utilization to milk, AAT and ME utilizations and ECM yield to feed intake -ratio were decreased on protein supplementation. In this experiment however rapeseed meal did not give responses of same level as was expected according to results of earlier experiments. Diets including faba bean increased silage intake and milk production compared to rapeseed meal diet. Rapeseed meal diet decreased silage intake 2,7 kg and milk yield 2,5 kg compared with faba bean diet. Mixture of rapeseed and faba bean resulted in the highest milk production being 2 kg more than on average on rapeseed meal and faba bean diets. Utilization of ME and ECM yield to feed intake –ratio were increased with rapeseed meal diet. According to this study rapeseed meal as a protein supplement can be substituted by faba bean in dairy cow diets on silage based diets.
  • Sorvali, Päivi (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.
  • Vähätalo, Sara (2022)
    Plant-based products with good nutritional and sensory quality are needed to facilitate dietary change towards using less of the unsustainable animal origin foods. Extrusion cooking is a way to produce these products cost effectively. A high quality dry-extruded product has porous structure and suitable hardness. These properties can be affected by adjusting the viscosity of the extruded mass. This master’s thesis discusses the properties of colloidal microcrystalline cellulose (cMCC) that affect the structure of dry-extruded textured protein products made of potato protein and faba bean flour made from germinated beans. The aim was to produce a porous, water binding domestic plant-protein product that can be used as part of healthy diet. The hypothesis was that cMCC increases water absorption capacity and changes the stiffness and expansion of the product by increasing viscosity of the mass. The viscosity of raw materials was first examined from flour mixtures and after this mixture of 70:30 faba bean:potato protein with 0; 1.5 and 3.0 % cMCC was extruded in 24; 27 and 30 % water contents. Moisture content, water absorption capacity, water solubility, sectional expansion index, physical properties of dry and swollen extrudates were examined. Products were photographed both dry and after swelling. The nutritional compositions were calculated based on raw material manufacturers’ information. The swollen products contained 15–22 g protein, 11–17 g carbohydrates and 3,5–47,7 fiber g/100 g moist extrudate (31–42 % dry matter) and could be categorized as source of fiber. cMCC improved flowing capabilities of the flour mixture which was observed as more uniform shape of extrudates. Cleaning the equipment was significantly easier with mixtures containing cMCC. cMCC did not increase water absorption capacity but it did decrease water solubility and increased stiffness. Viscosity measurements revealed that potato proteins did not gel. This information could not be utilized in detail to predict viscosities with extrusion because of different flour ratios.
  • Nieminen, Faisa (2023)
    Niacin is a water-soluble B-group vitamin, and it is a general name for nicotinic acid (NA) and nicotinamide (NAM). It is present in foods as available or bound niacin, which is not absorbable. Currently, the main sources of niacin in Finnish diets are meat and dairy products and with the recommendations to shift towards more plant-based diets, a question is raised if legumes would make potential protein-rich sources of niacin. Therefore, this thesis aimed to investigate legume ingredients as potential protein-rich sources of available niacin. Available niacin was studied from legume ingredients, extrudates, and seeds as a sum of NA and NAM. Stability of available niacin in high moisture extrusion was investigated and the influence of germination on available niacin was studied. Additionally, the propotions of bound niacin in legume flours and seeds were investigated. Available niacin was extracted with mild acid hydrolysis from legume ingredients, extrudates, and seeds. To study bound niacin, total niacin was extracted with acid-alkaline hydrolysis from legume flours and seeds. Ultra-high performance liquid chromatography and fluorescence detection (UHPLC-FLD) with post-column derivatisation were used for the quantification of NA and NAM. Oligosaccharides were analysed using high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD) to monitor the germination process. This thesis found that legume ingredients were good sources of available niacin, except for protein isolates. Furthermore, available niacin remained stable in high moisture extrusion and available niacin contents were higher when protein concentrates were favoured as ingredients, rather than protein isolates. Generally, legumes contained more NAM than NA. Germination increased available niacin in faba bean seeds by 30–40%, and oligosaccharide contents decreased. The results of this thesis assumed that legumes contain 20–60% of their niacin in bound forms. However, future research is needed to study bound niacin and niacin bioavailability in legumes, for instance, with a more sensitive and selective tandem-mass spectrometry (LC-MS/MS).
  • Liu, Chang (2015)
    The literature review related to faba bean proteins, the mechanism of protein oxidation and detection methods for protein oxidation as well as the relationship between lipid and protein oxidation. Native faba bean, faba bean treated by oven and microwave, as well as soy protein isolate were used as materials. The materials differed in their lipoxygenase activity. Oil-in-water emulsions were made of 10% purified (removal of antioxidants) rapeseed oil and 3% water soluble proteins that were extracted from flour samples. The emulsions were prepared by homogenizing using microfludizer. Oxidation took place in the oven at 37 °C in the dark with constant stirring by magnet stirrers. Sampling for measurements was carried out on day 0, 1, 4 and 7 from each replicate. Oxidative stability of was monitored by following lipid oxidation as formation of conjugated dienes and hexanal, and by following protein oxidation by measuring loss of tryptophan, formation of carbonyls and dityrosine through fluorescence detections both in the lipid phase and in the continuous phase. In this study, the degree of protein oxidation was generally consistent with corresponding lipid oxidation. Generally, the degree of protein oxidation in lipid phase of emulsions was higher than that in continuous phase, although the protein content was far less in the lipid phase. Both results implied co-oxidative relationship between lipid and protein oxidation. In addition, the results showed that thermal treatment or microwave irradiation can not only result in retarding or decreasing lipid oxidation by lowing lipoxygenase (LOX) activity, but also affect protein oxidation via lipid oxidation and the conformational changes of proteins.
  • Virtanen, Selina (2023)
    The seeds of faba bean (Vicia faba L.) contain volatile and non-volatile off-flavour compounds which are perceived as beany flavour, bitter taste, or astringent sensation, and which can impair the acceptability and liking of faba bean. The aim of this study was to investigate how hydrocolloids added to faba bean protein concentrate (FPC) affect its bitterness. The hypothesis was that the bitterness of FPC was significantly suppressed by the added hydrocolloids. A sensory evaluation study was conducted for six slurry samples that contained 25 % (w/w) FPC in water and of which five samples contained also one of the following ingredients selected based on preliminary tests: carboxymethyl cellulose, wheat starch, guar gum, NaCl, or sucrose. A trained panel (n = 10) assessed the bitterness and thickness of the samples on a line scale (from 0 = “not at all bitter/thick” to 10 = “very bitter/thick”) in three independent sessions. Additionally, the viscosities and pH of the samples were measured to study the possible changes that occurred during storage of the samples. Only a slight difference was found in the bitterness of the samples. The wheat starch sample was assessed as the least bitter and the thickest in mouth, and it was also the most viscous sample. However, these results need to be looked at critically as the viscosities of the samples decreased during the three-day storage, and as the panelists did not agree on the bitterness ratings of the samples. Hence, further research is needed to better understand the significance of hydrocolloids in masking the bitterness of faba bean.
  • Zhou, Xiao (2014)
    Divicine and isouramil are the causative agents of favism. The stability of divicine is of vital importance in faba bean detoxification. The literature review of this thesis focused on the hydrolysis of vicine to divicine, the oxidation processes of divicine and its stability studies. The main aims of this thesis were to produce divicine using the hydrolysis of vicine with ?-glucosidase, and study the effects of nitrogen/air atmosphere, reducing agent, pH and temperature on the stability of divicine. The identities of other compounds observed in vicine hydrolysis were also to be investigated. In addition, convicine was also hydrolyzed in the extracts and pure convicine fractions. Vicine and convicine were co-extracted from dehulled faba bean flour and were separated with preparative HPLC-MS. The extracts and the pure vicine and convicine fractions were hydrolyzed with ?-glucosidase to yield divicine and isouramil. The identities of the compounds formed during vicine fraction hydrolysis were studied by MS. In the following stability studies, the pure vicine fractions were hydrolyzed with ?-glucosidase under nitrogen and in the presence of (+)-sodium L-ascorbate. Moreover, the fractions were firstly hydrolyzed under air, next, the formed divicine was incubated at pH 3.0 or 5.0 at 20 or 37 ºC. An analytical HPLC method was used to study the changes during hydrolysis and stability tests. It was found that higher ?-glucosidase concentration and longer incubation period resulted in higher hydrolysis degrees of vicine and convicine. Further, vicine was hydrolyzed more rapidly at pH 3.0 than 5.0. Vicine was hydrolyzed to divicine. Divicine further generated two compounds, named compound 1 and compound 2 in this thesis. Their corresponding retention times and absorption maxima were: 2.15 min, 282 nm; 1.79 min, 262 nm; and 1.94 min, 210 nm. Compound 1 was directly generated from divicine. It was possibly oxidized divicine, but its characterization with MS failed in this study. Compound 1 decomposed to compound 2 at pH 5.0 at 20 ºC, but at pH 3.0 at 20 ºC, divicine might directly decompose to compound 2. Only one compound (named compound 3) was formed during convicine hydrolysis, and its retention time and absorption maximum were 2.50 min and 280 nm. Divicine and compounds 1, 2, and 3 were not stable, they finally decomposed to non-UV absorbing substances. Divicine was more stable under nitrogen than under air, and in the presence of (+)-sodium L-ascorbate than without its presence. Divicine decomposed similarly at pH 3.0 and 5.0 at 37 ºC, but at 20 ºC, divicine was more stable at pH 5.0. At both pH values, the stability of divicine was increased at 20 ºC compared with 37 ºC.
  • Vottonen, Laura (2018)
    Faba bean (Vicia faba L.) also known as broad bean is an ancient pulse, grown since Neolithic times. It is an excellent source of protein, energy and fibre to humans and animals. Recently in Finland, faba bean has featured heavily in meat replacements, meant for vegan consumers. Faba bean can also be grown further north, than soybean (Glycine max (L.) Merr.), making it a possible domestic plant protein source for Finns. The problem with faba bean is that the beans contain various anti-nutritional compounds. The major ones are vicine and convicine (v-c), located in the cotyledons of the beans, which means that dehulling the seeds does not remove them. V-c can cause favism in humans with G6PD gene mutation this is a disease where red blood cells are destroyed, in worst cases resulting in blood transfusions and death. V-c is also an anti-feedant to livestock and can among other things cause increase in mortality in poultry. Normal v-c content of faba bean is around 1%. There are low v-c faba beans that contain only 5-15% of the original v-c. Markers for this trait have been found, but gene controlling for this trait is not known yet. The synthesis pathway of the v-c is not known. There is a new hypothesis by Dr Fernando Geu Flores of The University of Copenhagen, where the v-c synthesis is an off shoot of another biosynthetic pathway. An experiment was done where RNA of two populations (one low v-c and other high) were compared to each other. The samples were taken during the seed filling period, which is thought to be when v-c is synthesized. Kernel, testa, pod and leaf tissues were collected and RNA of those extracted. Only kernel and testa samples were sequenced. This thesis focuses on the testa results. Results showed differences between the populations. Considering the new hypothesis, the results showed some differences in the beginning of the suspected pathway, with the high v-c population having a 4.97 fold increase compared to the low v-c population. Other differences were also noted, which may cast light on other steps in the pathway.