Browsing by Subject "Elintarviketieteiden maisteriohjelma"

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  • Helander, Riina (Helsingin yliopisto, 2019)
    Ruokaturvallisuuden merkitys korostuu tulevaisuudessa muun muassa ilmastonmuutoksen, kuluttajan toiveiden ja globalisaation myötä. Ammattikeittiöissä ruokaturvallisuus painottuu elintarvikehygieniaan ja sitä toteutetaan omavalvonnalla. Omavalvonnan kirjauksia, kuten lämpötilahallintaa, on perinteisesti tehty käsin paperille ja valvonnan mittaukset ovat olleet näytemittauksia jatkuvan valvonnan sijasta. Suomalaisissa ammattikeittiöissä omavalvonta toteutuu pääasiassa hyvin, mutta lainsäädännön tulkinta, resursointi ja epäyhtenäiset toimintatavat saattavat aiheuttaa haasteita. Ihmisen rooli ruokaturvallisuudessa on merkittävä. Tänä päivänä teknologian hyödyntäminen ruokaturvallisuudessa yleistyy ja uusia innovaatioita siihen kehitetään jatkuvasti. Omavalvonta voidaan digitalisoida ja automatisoida. Tämän tutkimuksen tavoitteena oli kehittää digitaalista omavalvonnan palvelua ruokaturvallisuutta edistävästi. Tutkimus oli laadullinen tutkimus, jossa menetelminä käytettiin puolistrukturoitua teemahaastattelua ja lyhyempää kyselyhaastattelua. Teemahaastattelujen haastateltavat olivat ammattikeittiöiden keittiöpäälliköitä tai ylemmän tason esimiehiä ja kyselyhaastatteluihin vastasi keittiöiden työntekijät ja kokit. Lisäksi haastateltiin neljää valvontaviranomaista. Teemahaastattelun teemoja olivat omavalvonnan merkitys, haasteet ja ajankäyttö, digitaalisen omavalvonnan vahvuudet, heikkoudet ja kehittäminen, palveluntarjoajan rooli sekä digitaalisen omavalvonnan vaikutus ruokaturvallisuuteen. Valvontaviranomaisilla teemana oli myös valvontakäynnit. Nauhoitetut aineistot litteroitiin ja analysoitiin sisällönanalyysilla teemoitellen. Haasteita omavalvonnassa tuottivat resursointi, lainsäädännön tulkinta sekä eri tasoinen osaaminen niin ruokaturvallisuudesta kuin digitaalisista työvälineistä. Digitaalinen omavalvonta lisäsi haastateltavien mielestä ruokaturvallisuutta automaattisen lämpötilaseurannan, läpinäkyvyyden ja sitouttamisen myötä. Digitaalista omavalvontaa tulisi kehittää kahdesta näkökulmasta. Ensinnäkin, digitaalisten työvälineiden tulisi ohjata käyttäjää tekemään ruokaturvallisia ratkaisuja, perehdyttää, motivoida ja sitä kautta sitouttaa paremmin omavalvonnan tekemiseen. Toiseksi, teknologian ratkaisuja ja automatisointia tulisi lisätä laajemmin koko omavalvontaan. Eri keittiöiden eri prosessit ja sitä kautta omavalvonnan toimintamallit tulee huomioida kehityksessä.
  • Haajanen, Hanna (Helsingin yliopisto, 2020)
    3-Chloro-1,2-propanediol (3-MCPD), 2-chloro-1,3-propanediol (2-MCPD) and 2,3-epoxy-1-propanol (glycidol) and their fatty acid esters are contaminants formed during processing fat containing foodstuffs at high temperatures. Mainly MCPD and glycidyl esters have been found to be formed in the deodorization process of oils, and in vegetable oils, such as palm oil, they have been measured at high concentrations. In accordance with the restrictions imposed by the European Commission, the levels of glycidyl esters must be especially monitored, as they have been identified as potentially carcinogenic compounds. The aim of the study was to introduce and validate a gas chromatographic analysis method for glycidyl esters and MCPD esters for the Customs Laboratory. The method was validated for two matrices: first for oils and then for powdered infant formulas. In addition, the success of the validation was examined by analyzing various oil samples previously received by the Customs Laboratory. The Customs Laboratory is also involved in the activities of the European Union Reference Laboratory, for which it was intended to participate in the reference measurement organized by the EU Reference Laboratory. The method for the determination of 3-MCPD, 2-MCPD and glycidyl esters in oils and infant formulas was carried out according to the guidelines of the European Union Reference Laboratory for Contaminants (EURL-PC). Determination of MCPD and glycidyl ester concentrations in oils and infant formulas included the following steps: fat extraction by liquid-liquid extraction (for infant formulas), addition of standards, solid-phase extraction, conversion of glycidyl esters to 3-MBPD esters, transesterification, neutralization, salting out, derivatization and analysis with gas chromatography-mass spectrometry system. Concentrations were determined using internal standard method. The method was validated for the following parameters: specificity, selectivity, limit of detection and quantitation, reproducibility, repeatability, trueness, linearity and working range, stability and measurement uncertainty. The analytical method developed for the determination of MCPD and glycidyl esters was successfully validated for oils and powdered infant formulas. The developed method proved to be specific and selective. The limit of determination was found to be 6.3 µg/kg, 1.3 µg/kg and 0.8 µg/kg for the oil matrix 3-MCPD, 2-MCPD and glycidyl esters. The limits of determination for the infant formula were 5.4 µg/kg, 3.0 µg/kg and 1.6 µg/kg for 3-MCPD, 2-MCPD and glycidyl esters. Recoveries for MCPD and glycidyl esters in the oil and powdered infant formulas were 83-105%. R2 for calibration lines were greater than 0.99, and the lines were linear over the entire measurement range of 2-1000 µg/kg. The relative standard deviation of repeatability and reproducibility was less than 20% for both matrices. The expanded measurement uncertainty for the MCPD and glycidyl esters of the oil and powdered infant formula was less than 50%. For all parameters, the requirements set by the Customs Laboratory and the performance requirements of Regulation (EU) 1881/2006 were met. A method validated for two matrices can then be accredited. The customs laboratory may use the developed method in the future to control 3-MCPD, 2-MCPD and glycidyl esters levels of oils and powdered infant formulas. In the future, the method could also be validated for new matrices, such as liquid infant formulas.
  • Bredehorst, Swantje (Helsingin yliopisto, 2022)
    Aflatoxin B1 (AFB1) is among the most potent carcinogens and mutagens known and significantly contributes to liver cancer. Mycotoxin contaminated crops, such as maize, groundnuts, or cocoa beans, are often destroyed, leading to a waste of resources. Recently, biotransformation of AFB1 by lactic acid bacteria (LAB) has been receiving growing attention. Biotransformation refers to structural change induced by enzymes or bacteria and can yield modified compounds of lower toxicity or non-toxicity compared to their precursors. Despite this growing interest, previous studies have primarily focused on the AFB1-reduction potential of LAB and biotransformation products have not been studied extensively. Therefore, this work aimed to screen twelve LAB for AFB1 biotransformation properties and analyze its degradation products. LAB were incubated in growth media for 24, 48, or 72 hours and ultra-performance liquid chromatography with fluorescence detection (UPLC-FL) was employed to measure AFB1-reduction and determine whether new fluorescent compounds appeared. Ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used to assess the structure of the degradation products. The highest biotransformation was achieved by Lactobacillus helveticus FAM22155 (28.9 % after 72 h) and Lactobacillus helveticus FAM19191 (19.7% after 72 h). Two new peaks at 2.0 and 3.3 min retention time were observed with UPLC-FL and considered as possible degradation products. As the amount of the latter compound was very low, it could not be further analyzed. The peak at 2.0 min had a mass-to-charge ratio of 207. Two possible structures for this compound were proposed, but due to low intensities, further studies to confirm the structure are needed. This study showed that Lactobacillus helveticus can reduce almost a third of the AFB1 concentration. However, this study highlighted the challenges of identifying degradation products, and it was concluded that the extraction prior to MS should be optimized to identify degradation products. Determining the structure of the degradation products is necessary in order to evaluate whether the biotransformation results in less toxic products. In addition to evaluating the biotransformation efficacy in complex food matrices, it should be studied to determine whether biotransformation represents a promising means of reducing AFB1.
  • Zítková, Kateřina (Helsingin yliopisto, 2022)
    Hexanal is a highly volatile liquid that can prolong the shelf life of fruits and vegetables (Paliyath and Subramanian 2008). Previously, Lehtonen et al. (2020) introduced a freeze-dried active packaging material which was continuously releasing hexanal through the naturally occurring lipid oxidation reactions of sunflower oil. In this study, nine different sunflower oil-based matrices were characterized at different stages of their preparation process. They contained crystallization modifiers (acylglycerols, phytosterols, or their blend), coating materials (gum Arabic and maltodextrin), and were produced by spray-drying of an emulsion. The crystallization modifiers in the matrix may enable the control over the start of the reaction for hexanal release. The emulsions with crystallization modifiers were significantly unstable, their viscosity increased with an increasing proportion of gum Arabic, and they contained crystalline regions from the first day of preparation. All tested emulsions formed a white powder after spray drying and the powder particle sizes were characterized. The differential scanning calorimetry (DSC) did not reveal any melting point of the lipid phase in majority of the powder samples. However, the DSC results showed that the melting temperatures of corresponding oleogels with acylglycerols and acylglycerol/phytosterol blend were 64 and 56.6 °C, respectively. In this thesis, emulsions containing acylglycerols and/or phytosterols were characterized and shown to be suitable for the encapsulation by the spray drying technique. Further studies focusing on the hexanal release from the matrix need to be performed since no hexanal release was detected from the powder samples.
  • Tuccillo, Fabio (Helsingin yliopisto, 2021)
    As the number of vegetarians and flexitarians is increasing, the demand for meat alternatives is following the same trend. Faba bean is a promising crop for environmental, health, and social reasons. From its seeds, several products can be produced, such as flour, protein concentrate, and protein isolate. These materials can be further processed for the development of texturized vegetable proteins. In this context, high moisture extrusion (HME) is an innovative technology, which requires more water, but milder temperatures than the more studied low moisture extrusion. The present thesis aimed at covering the current knowledge gap on this technology, by focusing on the flavor aspect of faba bean-based meat alternatives. The volatile profile of faba bean flour, protein concentrate, protein isolate, and mixtures was studied before and after high moisture extrusion by means of HS-SPME-GC-MS. Comparisons were made between raw materials (flour, protein concentrate, protein isolate, mixtures) and extrudates. The effect of the origin (Canadian and Finnish) of the protein concentrate was also investigated. Materials were also characterized for the following aspects: moisture, ash, protein, lipids, lipid-degrading enzymes (lipase and lipoxygenase), free amino acids, and free mono-, di-, and oligosaccharides. Several classes of volatile compounds were observed in both raw materials and extrudates, namely organic acids, alcohols, aldehydes, alkanes, alkenes, aromatic compounds, furans, esters, ketones, nitro compounds, and terpenes. Many compounds were characteristic of only one material, demonstrating that the formation of certain volatiles was product dependent. However, some other compounds were found in all materials, such as 1-hexanol, hexanal, and 2-pentylfuran. Literature addresses these compounds as responsible for the beany flavor. HME caused the inactivation of lipase and lipoxygenase but did not prevent the formation of lipid oxidation products. Products from Maillard reaction were not found in the extrudates. After HME, 1-hexanol levels decreased, whereas the abundance of 2-pentylfuran significantly increased. The behavior of hexanal after HME was less stable and predictable than the two beforementioned compounds. Not only these novel findings could have application in product development, but they also laid the basis for further research aimed at improving the flavor of faba bean.
  • Tukia, Nea (Helsingin yliopisto, 2021)
    The objective of the research was to compare collagen characteristics, general meat quality parameters and carcass characteristics of three different muscles from freely pasturing Mangalitza Red breed and highly bred domestic/commercial pig breed. Collagen content and collagen solubility was analyzed by hydrolyzing the three different muscle samples. Meat quality parameters were analyzed previously by Natural Resources Center (Luke). The pH of Mangalitza LD muscle varied from 5.41 to 5.64, SM muscle from 5.53 to 5.75 and IS muscle from 5.74 to 5.87, IS having higher pH than the two other muscles (P < 0.05). The pH of commercial pig LD muscle varied from 5.47 to 5.75, SM muscle from 5.52 to 5.77, and IS muscle from pH 5.96 to 6.51, IS having higher pH than the two other muscles (P < 0.05). Breed had effect on pH of muscle IS (P < 0.05), but no effect on muscles LD or SM (P > 0.05). The color of muscles of Mangalitza was darker than commercial pig’s in all the three muscles (P< 0.05). In Mangalitza, LD was lighter than SM and IS, but in commercial pigs, LD and SM were lighter than IS (P < 0.05) Collagen content of all three muscles of Mangalitza differed from each other (P < 0.05) and the collagen content of LD and SM were lower (P < 0.05) than of commercial pig’s collagen content. In commercial pig, collagen content of LD and SM muscles were lower than in IS muscle (P < 0.05). Collagen solubility of all three muscles of Mangalitza differed from each other (P < 0.05) and the collagen solubility of SM and IS were lower (P < 0.05) than of commercial pig’s collagen solubility. In commercial pig, collagen solubility of LD and SM muscles were lower than in IS muscle (P < 0.05). In contrast to collagen content, collagen solubility of LD muscles did not differ between the breeds (P > 0.05). The amount and solubility of collagen did not deviate from normal; it can be concluded that this study did not provide any new information other than the collagen content and solubility of Mangalitza Red breeds muscles of LD and SM.
  • Uusitalo, Mari (Helsingin yliopisto, 2022)
    Cronobacter spp. are opportunistic human pathogens. They can cause infections in infants and illness in older children and adults. There is also a high case fatality rate. Cronobacter spp. are found in dried foods, such as powdered infant formulas and Cronobacter spp. have caused serious cases of infection in worldwide. Therefore, Cronobacter spp. should not be present in powdered infant formulas that reach consumers. Cronobacter do not survive heat treatment. It is therefore likely that Cronobacter will migrate to the product from the environment or from heat-sensitive nutrients added after pasteurization. The data for the study was collected from the production control systems of the powder plants. Data was used for the period 2018-2020. Two powder plants, Plant A and Plant B were compared. Cronobacter results of environmental were compared with different climate variables using regression analysis, for example. Statistical analysis was performed with Minitab software. It was investigated whether the positive Cronobacter results were related to the microbiological results in the products. One subject of the review was whether seasonal variability was present in Cronobacter environmental samples. It was also examined whether explanatory factors were found for the Cronobacter results of individual targets. Based on the results of the study, there was no clear relationship between positive environmental sample results and weather conditions. Seasonal variation is also unrelated to environmental sample results. There was no statistical association between positive Cronobacter environmental results and microbiological results of the products. When examining the sampling targets, most of the positive results were found in the floor sampling targets. Based on the results, it would be a good idea to consider whether it is necessary to make changes in the hygiene areas or tighten the hygiene requirements. The use of additional shoe covers should be on option, for example. The prevention of Cronobacter in the environment is particularly important. Possible contamination of the products poses not only health risks but also financial damage. Rejection of production batches due to Cronobacter contamination can be economically significant.
  • Ylipoti, Kerttu-Maaria (Helsingin yliopisto, 2020)
    Take away food has increased in popularity in the past years. However, there are not many cardboard-based take away packaging options for restauranteurs. Plastic materials such as expanded polystyrene are most commonly used for take away packaging, but the single-use plastics directive by the European Commission has added polystyrene as one of the materials to be banned by 2021. Additionally, consumers are also becoming more educated on material sustainability, which brings added pressure and opportunity for developing new alternatives to the market. This case study implemented customer-dominant logic (CDL) to the design process of a cardboard-based take away package. In CDL, value-creation is perceived as a personal, subjective and holistic process, where the customer is in the center of the value formation process. The aim was to create a CDL based design framework and test whether it resulted in a cardboard-based take away package which created value for the consumer. The case study also aimed to uncover the factors of take away packaging which contributed to the value creation for customers. The results were collected through three consumer studies, which used qualitative methods such as responsive interviews and the Value Toolkit®. It was concluded that cardboard as a material was seen as renewable and easy-to-recycle. The cardboard-based package was successfully designed, as it was rated highest in comparison to a polystyrene-based package and a compostable bagasse package in the final consumer study. It was discovered that out of the four value types: performance, experience, status value, and responsibility, consumers thought performance was the most important in take away packaging. The CDL based framework for package design was successful. The framework can further be studied with collateral case studies, where one design team uses the CDL based framework and the other uses a more traditional approach to design.
  • Laitila, Tiina (Helsingin yliopisto, 2022)
    Aflatoxin B1 (AFB1) is a naturally occurring toxic compound produced by various types of fungi. The presence of AFB1 in food and feed can lead to severe illness, which makes it a serious threat to humans and animals. Due to global climate change, the cases of AFB1 contamination in food will increase since high temperature and humidity favour fungal growth and the production of AFB1. The bioavailability of AFB1 can be decreased by adsorption or biotransformation. Adsorption happens by the utilization of different AFB1 binding agents, which can be either mineral and organic or biological adsorbents. Mineral and organic adsorbents are only used in feed since they may also bind to nutrients. Biological adsorbents are being studied more actively since they maintain the nutritional value of the food. Studies show that Lactic acid bacteria (LAB) can be used to bind AFB1 from contaminated foods. The aim of this research was to study the capacity of different LAB (viable and nonviable) to adsorb (bind) AFB1 under different pH conditions. The research first evaluated the binding ability of AFB1 by 13 viable and nonviable LAB strains at pH 7. The best binding strains were selected for further study at pH 3 to mimic gastric pH. The AFB1 binding with cells was performed at 25℃ for 90 min. To determine the binding capacity, the solutions were centrifuged and free AFB1 in the supernatant was extracted with acetonitrile, and quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was used to clean up the samples. AFB1 concentration was determined by ultra-performance liquid chromatography and fluorescence detection (UPLC-FLD). The LAB strains used in this research were shown to have the ability to bind AFB1. Binding efficacy of AFB1 depended on the bacterial strain. Viability and pH also affected the binding ability. All nonviable cells showed better binding ability (44.9–71.3%) compared to the viable cells (29.0–49.4%). The strains also had better binding capacity at lower pH regardless of the cell viability. The highest binding efficacy (71.3%) was achieved by the nonviable cell of Lactobacillus helveticus FAM 22155 at pH 3. The results of this thesis showed that some LAB strains bind AFB1 and that the binding is stable under stomach conditions. Studies to investigate the stability of the binding under simulated upper and lower gastrointestinal (GI) tract conditions (in vitro digestion) and in vivo studies are needed in order to provide further evidence of the applicability of LAB in lowering the bioavailability of AFB1.
  • Kazerani Garcia, Afsane Aurora (Helsingin yliopisto, 2021)
    Non-communicable diseases such as cardiovascular diseases (CVDs) and erosive, unsustainable industrial fat-production methods pose two of the biggest threats to human health in great part of our planet. CVDs and obesity have been linked to diets high in fat and low in dietary fibre, pushing food manufacturers to adapt to more sustainable ingredients. For this reason, this research developed and researched about a new and sustainable plant-based oleogel intended to act as a substitute for saturated and hydrogenated fats. Its characterization was conducted through several techniques, including optical and field emission electron scanning microscopy, differential scanning calorimetry, Fourier transmission infrared spectroscopy, and synchrotron X-ray powder diffraction. The results showed that the build-up of the formation of the new oleogel was possible, while ensuring that both processing requirements and ingredients are readily available at food manufacturing plants, globally. These findings pose a great opportunity for plant-based fat-replacement formulations, through a sustainable approach. Considering previous studies, this novel system could potentially help in reducing the burden of obesity and CVDs, turning it into a functional food component. Further research on food applications and digestibility models could give more insight on the future applications of this fat-replacement system.
  • Törnroos, Tatu (Helsingin yliopisto, 2021)
    Cowpea (Vigna unguiculata) is one of the most important legumes in the world due to its high nutritional content. Its nutritional value is, however, hindered by different anti-nutrients, such as phytic acid (PA), which can lower the bioavailability of minerals and proteins. PA is a nutritionally significant compound found in many plant materials, such as cereals and legumes. PA is myo-inositol-1,2,3,4,5,6-hexakis dihydrogen phosphate (IP6) by chemical nomenclature. Measurement of PA is challenging, due to its high charges and its low content, amongst other factors. The primary aim in the thesis was to create an accurate, selective, and sensitive UPLC-QTof-ESI-MS method for quantification of PA from legumes, cereals, and other plant materials. The secondary objective was to determine PA content in raw, fermented and phytase-treated white cowpea flour and investigate the effectiveness of the processing methods on PA hydrolysis. PA content in white cowpea has been previously determined with methods lacking the capability to directly measure only PA content, without also adding in the concentration of smaller inositol phosphates (InsP) or other phosphorus containing compounds. Therefore, the presumption was that the measured PA concentration should be lower when using the selective UPLC-QTof-ESI-MS method. Besides white cowpea flour, the concentration of PA in red cowpea, wheat bran, sorghum, wheat fraction and rapeseed protein concentrate flours was also measured to investigate if the method works for other plant matrices as well. The sample preparation method consisted of two-hour extraction in 0.5 M HCl, a neutralization step, lyophilization, reconstitution with 5% MeOH and addition of adenosine 5′-monophosphate monohydrate (AMP) as internal standard. The samples were then analyzed with UPLC-QTof-ESI-MS, with electrospray ionization on negative ion mode (ESI-). The PA quantification method had excellent precision, selectivity, repeatability, and linearity (R2 = 0.991). Accuracy was good and the recovery of 100% resulted in a high level of trueness. The LoD was determined as 3.22 µg/mL but could be possibly lowered. The PA content in white cowpea flour was 5.91 mg/g dry weight. As was presumed, this result was lower than previously reported in literature. The method was also relatively suitable for the other plant samples. However, wheat fraction, rapeseed protein concentrate, and sorghum flours gave unexpected results. In the fermented sample the PA content was 3.30 mg/g and in the enzyme-treated 0.09 mg/g (or 12.4 µg/mL). However, the fermentation and enzymatic treatments did not reduce the PA concentration under the threshold of <3.3 µg/mL, where iron cation chelation still strongly takes place. The processing method could be improved by increasing the phytase dosage or increasing the reaction times to achieve higher hydrolysis of PA.
  • Palsola, Mira (Helsingin yliopisto, 2022)
    African crops are sustainable and healthy alternative ingredients for potential use in various gluten-free products among traditional African foods. In this thesis maise-based, gluten-free crackers with 50% cereal (amaranth, sorghum and teff) and 50% and 75% legume (Bambara groundnut and cowpea) replacements were produced, and their baking performance and technological properties were examined. The effect of sorghum and cowpea flour's bioprocessing and mechanical raw material modifications on cracker technological and sensory properties was studied. The thesis aimed to solve whether maise and African crop flours could be used in gluten-free crackers and how would they affect nutritional values, baking performance and technological and sensory properties in gluten-free crackers. The nutritional calculations indicated that African crop replacement increased fibre content at least by 2.4% and protein by 1.9 E% compared to 100% maise cracker. Crop replacements improved the dough elasticity and bakability and darkened the cracker surface. African crops and higher protein content increased cracker hardness and improved the rising ability. The highest hardness rate was measured with protein fractionated cowpea (31.55 ± 3.17 N, maise 4.02 ± 1.79%) and puffiness with Bambara groundnut 75% (43.57 ± 3.29%, maise 21.93 ± 0.002%). Raw material modifications changed the sensory profile of sorghum and cowpea crackers significantly by decreasing graininess in sorghum and beaniness in cowpea.
  • Kalmu, Niina (Helsingin yliopisto, 2021)
    Poultry meat has become popular in human diet and to secure the growing demand of poultry meat, breeders have developed broilers with fast growth and high breast muscle yield. Because of this genetic selection modern broilers are suffering from various quality defects in their breast muscles, one of which is called WB myopathy. The aim of the thesis was to study whether exercise, WB status or age have effects on ultimate pH and glycolytic potential (sum of total glucose and lactic acid content, given as lactate) in M. pectoralis major of modern broilers chickens. A total of 154 post-rigor breast muscle samples of male broilers of hybrid Ross 308 were used in this study. Broilers were divided randomly into three groups (A-C). Group A birds were not subjected to any exercise during the experiment. Group B birds lived 25 days exactly like group A but after that the drinking water dispensers was elevated to a higher level. Group C birds had their drinking water dispensers elevated to a 5 cm higher level after three days, and it was risen stepwise to 25 cm during the study. Broilers were slaughtered randomly from different groups at 20, 30 or 41 days old. Group B results were disregarded due to technical problems. Initial and ultimate pH, total glucose, free and in glycogen, and lactic acid contents for glycolytic potential, were determined from the breast muscle samples. The results showed that there were no differences between groups A and C (p > 0.05). There were differences between normal and WB cases in ultimate pH (pHu; p = 0.000), total glucose content (p = 0.000), lactate content (p = 0.007) and glycolytic potential (p = 0.000), but the pH values 5 minutes after death showed no significance (pH5; p = 0.190). There were differences in pHu, total glucose and glycolytic potential (p = 0.000), and lactate (p = 0.007), between ages 20, 30 and 41 days old birds. As the severity of WB increased in the breast muscle, the pHu increased and total glucose, lactate content and glycolytic potential decreased. The correlations showed significant relationships between WB score and all the above variables (p < 0.000). The results of the current study show that exercise does not have an effect on the levels of carbohydrates in M. pectoralis major of modern broiler chickens, but WB status and increasing slaughter age result a decrease in glycolytic potential and increase in ultimate pH.
  • Kinnunen, Eveliina (Helsingin yliopisto, 2020)
    Infant formulas are breast milk substitutes for 0 to 12-month-old infants. Addition of milk fat to infant formulas leads to an increase in solid fat content. Infant formulas are oil-in- water emulsions in which oil is dispersed into a continuous aqueous phase. Milk fat crystallization leads to partial coalescence and creaming which are types of instability in emulsions. Partial coalescence occurs when two droplets containing crystals collide and they partially coalesce by making contact between their oil phases. The aim of this thesis was to study if milk fat crystallization leads to partial coalescence which leads to a higher rate of creaming or the increasing density of crystallizing droplets leads to a lower rate of creaming. Also, the aim was to study the effect of interfacial layer on partial coalescence. Milk fat crystallization and emulsion stability were investigated from four series of oil-in- water emulsions containing different oils in different concentrations and either whey protein or lecithin as stabilizer. The samples were stored at 5, 20 and 40 °C and measured after 0, 7 and 28 days of storage. The crystallization of bulk fat and oil in emulsions were studied with melting enthalpies measured with differential scanning calorimetry. Emulsion stability was examined with particle size distribution, instability index and creaming velocity measurements. According to the results combining vegetable oil and butter oil, and emulsifying the fat decreases the total enthalpy change and crystallization onset temperature of oils. Mixing vegetable oil and butter oil before homogenization decreased crystallization onset temperature and total enthalpy change because the oils were in same droplet, and made the emulsions behave more like vegetable oil emulsions. Mixing the oils after homogenization made the emulsions behave similarly to butter oil emulsions. Whey protein was found to be a better stabilizer of emulsions than lecithin at 5 and 20 °C, but at 40 °C some Maillard reaction was noticed. It was suspected that the concentration of lecithin in emulsions was insufficient. Based on the results it could be stated that the increasing density due to crystallizing droplets made the emulsions more stable against creaming. Best stability of emulsions containing oil mixtures would be achieved if butter oil and vegetable oil were mixed after homogenization and whey protein used as emulsifier.
  • Nykänen, Venla (Helsingin yliopisto, 2022)
    Herbs are valued for culinary and health purposes and their metabolism and chemical composition can be influenced with LED lighting. This Master’s Thesis aimed to study how different spectra (green, blue, and white light) affect the sensory properties of hydroponically grown dill (Anethum graveolens L.) and coriander (Coriandrum sativum). The hypothesis was that green light produces more soapy and musty flavours in coriander, whereas blue light produces more citrus and typical coriander-like flavours. For dill the hypothesis was that blue and green light treatments produce stronger flavours compared to white light. A generic descriptive analysis method was chosen, and trained panels created sensory profiles for three light treatment and one commercial coriander and dill samples. Intensities of smell, taste and flavour attributes were evaluated using a line scale (0 = not at all to 10 = extremely) in three replicates. Study was conducted during the COVID-19 pandemic in the sensory laboratory conditions (ISO 8589). One-way ANOVA showed that light treatments had only slight impact on the sensory profiles of coriander and dill. In coriander blue light produced significantly lower lemon odour intensity compared to green light treatment. In dill total odour intensity was significantly lower in blue light sample compared to white light and commercial samples. Otherwise, one-way ANOVA did not show significant differences between samples. However, principal component analysis (PCA) implied that samples differed. Two-way ANOVA results showed that neither panel worked uniformly and deviation among intensity scores was observed. Herb samples proved to be rather difficult to evaluate and more extensive training could have improved panel’s performance. In future consumer study could be performed to study if spectrum affects the hedonic response to these herbs.
  • Juutilainen, Zoja (Helsingin yliopisto, 2022)
    Merkittävä osa elintarvikeperäisistä mikrobiologisista ja kemiallisista vaaroista kasvaa, leviää tai syntyy kuluttajien kotona. Kuluttajat vaikuttavat ruoan turvallisuuteen käsittely- ja säilytystottumuksillaan, joiden arviointi on nykyisessä riskinarvioinnissa vaikeaa puutteellisen aineiston takia. Jotta riskinarviointi olisi paikkansapitävä, ja sen mukaan luodut ohjeistukset, säädökset ja lait mahdollisimman kohdennettuja, tulee kuluttajien vaaroille altistumisen arviointi olla aiempaa tarkempaa. Tutkimus suoritettiin Ruokaviraston toimeksiantona, ja sen tarkoitus oli luoda valmis kyselypohja riskinarvioinnin tueksi. Kyselylomakkeiden avulla pyrittiin selvittämään kuluttajien kalan ja lihan käsittely- ja säilytystottumuksia kotioloissa, millä on merkittävä vaikutus kemiallisille ja mikrobiologisille vaaroille altistumisessa. Tutkimus koostui kahden kyselylomakkeen luomisesta ja niiden validiuden arvioimisesta yksilöhaastatteluilla (n=30, 18–83 v.). Tutkimuksessa havaittiin, että lomakkeet eivät sellaisenaan olleet valmiita käyttöönottoon. Osa kysymyksistä ei soveltunut haluttuun tarkoitukseen, eikä niillä täten saatu kerättyä tarvittavaa aineistoa. Ennen lomakkeiden käyttöönottoa myös kyselyissä käytettyä 7-portaista ankkuroitua asteikkoa tulee muokata numeerisemmaksi, sillä sanalliset ankkurit olivat monitulkintaisia. Tässä tutkimuksessa ehdotettujen muokkausten jälkeen lomakkeiden validiteetti olisi tärkeää tutkia myös seurantatutkimuksen avulla, mutta myös sellaisenaan lomakkeet tuovat tarvittavaa aineistoa kuluttajien kotikäyttäytymisestä.
  • Astola, Anni (Helsingin yliopisto, 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.
  • Niklander, Katariina (Helsingin yliopisto, 2021)
    Enzyme treatments have been able to reduce the amount of oligosaccharides and phytates in legumes. Enzyme treatment has the potential to improve the sensory properties of the product and reduce the stomach symptoms they cause. The aim of the study was to find out how enzyme treatment affects to the sensory properties of spoonable yogurt-like faba bean and pea-based snack samples. In addition, an online survey was made to map stomach symptoms caused by legumes and to study their effect on the use of legumes and legume foods. The methods used in the study were generic descriptive analysis with a trained panel (11 panelists) and an online survey made with E-lomake (227 respondents). In addition, the benefit data from the second study of the project for pea snacks were used (27 evaluators). In the generic descriptive analysis, there were a total of 6 spoonable snack samples to be examined (3 faba bean samples and 3 pea samples). Both raw materials had a control sample (no enzyme treatment) and two differently enzyme treated samples. In the generic descriptive analysis, the panel evaluated 12 properties from the samples: color, fruity and legume-like odor, runniness, grainy, powderiness, thickness, sweet, bitter, legume-like, bitter aftertaste and total intensity of aftertaste. Enzyme treatment had an effect on texture and mouthfeel properties, but not on taste, color, or odor. As a result of the enzyme treatment, the structure thickened and became smoother. The raw material had an effect on all the properties to be evaluated, except for the legume-like flavor. Enzyme treatment had no effect on the pleasantness of spoonable pea snacks. According to the survey, the most common symptoms caused by legumes were flatulence and bloating. Of the legumes and legume foods, chickpeas and pea soup were the most common foods to cause symptoms. More than half (about 65 %) of the respondents stated that they would definitely or probably eat more legumes if they did not cause stomach symptoms. More than half (67 %) would also be absolutely or probably willing to try enzyme-treated legume foods. Based on the results, it is worth further investigating the effects of enzyme treatment on sensory properties, especially in terms of structure / mouthfeel. In addition, the effect of fermentation on the sensory properties of pea and faba bean spoonable snacks should also be studied, as fermentation has been found to improve the sensory properties and nutritional value of plant-based spoonable snacks. Based on the responses to the survey, there seems to be a demand for legume products that cause less stomach symptoms.
  • Kang, Jingran (Helsingin yliopisto, 2021)
    Glucuronoxylans (GX) from birch and galactoglucomannans (GGM) from spruce are capable of forming and stabilising oil-in-water emulsions. Phenolic compounds co-extracted with wood hemicelluloses enhance the stability of an emulsion. The stabilising mechanisms of emulsions prepared from GGM have been studied in detail, while emulsions stabilised by GX require further investigation due to the complexity of their chemical compositions. On the contrary to GGM-based emulsions, pectin was found at the interface of GX-based emulsions. We hypothesise that pectin plays a role in emulsification and affects the bimodal droplet size distribution of an emulsion. Therefore, this study aimed to assess the functionality of pectin in GX-based emulsifiers with pectinase. First, pectinase treatment conditions were optimised, namely reaction medium, time, temperature and pectinase dosage. The enzymatic hydrolysis of pectin was confirmed quantitatively by gas chromatography (GC). To investigate the role of pectin in emulsion stabilisation, rapeseed oil-in-water emulsions were prepared from pressurised-hot-water-extracted (PHWE) spray-dried GX (sGX), sGX treated with pectinase (p-sGX), sGX treated with pectinase and centrifugation (c-sGX), ethanol-precipitated GX (eGX), eGX treated with pectinase (p-eGX), and eGX treated with pectinase and centrifugation (c-eGX). The stability of the 6 emulsions was measured in a 2-week accelerated storage stability test. Phenolic compounds originating from lignin were characterised by pyrolysis gas chromatography-mass spectrometry (pyrolysis GC-MS) to monitor the changes of lignin contents before and after pectinase treatment. It is concluded that the optimum conditions of pectinase treatment were: reaction medium: 0.1 M sodium acetate buffer (pH 4.5), reaction temperature: 50 °C, reaction time: 2 hours, pectinase dosage: 304 U per gram of birch hemicellulose. Results from GC analysis of free monosaccharides confirmed that only pectin was hydrolysed under the abovementioned pectinase treatment conditions and that the hemicellulose backbone structure remained intact. Emulsions prepared from sGX remained stable for over 2 weeks, while creaming was observed in emulsions stabilised by p-sGX and c-sGX during the second week of storage. Emulsions prepared from eGX, p-eGX, and c-eGX remained stable for over 2 weeks. Results from pyrolysis GC-MS indicated that pectinase treatment removed some of the phenolic compounds in GX. Therefore, it was concluded that associations existed among GX, lignin, and pectin. Pectin took part in the formation and stabilisation of emulsions prepared from sGX and eGX by connecting lignin to GX.
  • Rissanen, Janina (Helsingin yliopisto, 2020)
    Securing an adequate protein intake raises questions for the future, and various plant protein products have grown in popularity in recent years. Tofu is one of the most popular vegetable protein products due to its versatility. Also, its different structural types are appealing to consumers. One way to increase the value of other grain legumes closer to soybeans would be to develop a tofu analogue from them. Faba beans are potential for this purpose, as they can be cultivated under the northernmost conditions, they are as rich in protein like soybeans and the proteins within soybean and faba bean are similar in structure. This study complements research related to the gelation of faba bean proteins. The aim was to study how different coagulants, their contents and different faba bean protein contents in the emulsion affect the resulting gel structure. The gels produced by each coagulant were examined separately so that the variables, i.e., coagulant and protein contents, were given three different values. The protein content of the emulsion was either 6, 7 or 8% (w/v), and the contents of coagulants were as follows: transglutaminase (TG) 5, 25 or 50 U/g of protein, gluconodeltalactone (GDL) 0.3, 0.65 or 1%, citric acid 0.14, 0.16 or 0.18% and calcium sulphate (CaSO4 · 2 H2O) 0.5, 1 or 1.5% (w/w). The structures of the gels were compared based on the results of Texture Profile Analysis (TPA) and sensory observations, and in addition, the samples were examined for the interactions formed between the proteins. This was done by dissolving the gels in various solvents. Of the gels studied, the most different structure was produced by transglutaminase, which provided a solid-like gel structure at the highest content combined with the highest protein content in the emulsion. Its TPA value for hardness was the highest. The interactions between proteins also differed most when comparing the results of other gels to transglutaminase gels. A probable explanation for these results was the strong isopeptide bonds formed by TG. GDL, citric acid or calcium sulfate did not produce such a solid gel structure, but the structures of the samples were much softer, part almost liquid. The protein content had a statistically significant effect on the hardness of gels coagulated with TG and calcium sulfate, among others. The coagulant content also affected the results of the TPA measurements, but they had less effect than the protein content.