Browsing by Subject "processing"

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  • Kauppinen, Joonas (Helsingin yliopisto, 2019)
    Edible insects, such as house crickets (Acheta domesticus) are environmentally friendly, nutritious and safe alternative to meat, when special details such as allergenic potential and antinutrients are considered. The goal of this Master’s thesis is to study the processing methods and parameters of house cricket in creating flour for food applications that is safe and of optimal quality. The thesis hopes to provide a reference for parameters used in house cricket drying and milling, with the equipment available. Furthermore, the goal is to study the optimal time to get below critical value in water content of 10 % and within critical values in water activity of 0,25-0,45 with an oven and a freeze-dryer. The samples within the critical safety values with minimal drying time are then milled with centrifugal mill with two different sieve-sizes and particle size distribution is measured and compared between oven-drying and freeze-drying, the two sieve-sizes and to reference flours. Particle size range of 45-150 μm was used as a goal. Optimal measured drying time at T=70 °C for oven-drying was 5 hours. For Freeze-drying at Tp=25 °C, Tc=-87 °C, p=1 mbar was 6 hours. Of the optimally dried samples, Oven-dried sample milled with 0,5 mm sieve size had the lowest mean and median particle size followed by Freeze-dried sample milled with 0,5 mm sieve size. The 5-hour Oven-dried sample milled with 0,5 mm sieve size was thus the closest to the optimal product, because it had the smallest particle size from all the samples with minimal drying time. Samples milled with 1 mm sieve size had coarser mean and median particle size similar to that of the reference samples obtained from the industry. Furthermore, it can be concluded that compared to reference flours, finer house cricket flour can be milled with 0,5 mm sieve size. On the other hand, 1 mm sieve size with the particular centrifugal mill used yields a flour with similar coarse particle size than those used in the industry today. However, Oven-dried samples caused smearing during milling and thus the relationship between drying method and smearing should be studied further. All of the milled samples showed narrower particle size distribution compared to the Reference samples, which indicates a more homogenous flour and thus is considered a desirable trait in this study, when the specific food application is not known. Furthermore, all samples including the Reference samples showed negative skeweness in terms of their particle size distribution.
  • Tauriainen, Vappu (Helsingin yliopisto, 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.
  • Muroya, Susumu; Ueda, Shuji; Komatsu, Tomohiko; Miyakawa, Takuya; Ertbjerg, Per (2020)
    In the past decades, metabolomics has been used to comprehensively understand a variety of food materials for improvement and assessment of food quality. Farm animal skeletal muscles and meat are one of the major targets of metabolomics for the characterization of meat and the exploration of biomarkers in the production system. For identification of potential biomarkers to control meat quality, studies of animal muscles and meat with metabolomics (MEATabolomics) has been conducted in combination with analyses of meat quality traits, focusing on specific factors associated with animal genetic background and sensory scores, or conditions in feeding system and treatments of meat in the processes such as postmortem storage, processing, and hygiene control. Currently, most of MEATabolomics approaches combine separation techniques (gas or liquid chromatography, and capillary electrophoresis)-mass spectrometry (MS) or nuclear magnetic resonance (NMR) approaches with the downstream multivariate analyses, depending on the polarity and/or hydrophobicity of the targeted metabolites. Studies employing these approaches provide useful information to monitor meat quality traits efficiently and to understand the genetic background and production system of animals behind the meat quality. MEATabolomics is expected to improve the knowledge and methodologies in animal breeding and feeding, meat storage and processing, and prediction of meat quality.
  • Jokinen, Iina; Pihlava, Juha-Matti; Puganen, Anna; Sontag-Strohm, Tuula; Linderborg, Kaisa M.; Holopainen-Mantila, Ulla; Hietaniemi, Veli; Nordlund, Emilia (2021)
    The aim of this study was to determine whether the properties of the native oat grain or non-heat-treated groats (laboratory-scale dehulling) can be used to predict the quality of the industrially produced oat flour produced from heat-treated groats. Quality properties such as the color, hectoliter weight, thousand seed weight and hull content of Finnish native grains (n = 30) were determined. Furthermore, the relationship between the properties of the native grains and the chemical composition of the raw oat materials before and after the milling process were studied. A significant relationship (p < 0.01) was observed between the thousand seed weight of the native oat groats and the chemical composition of the industrially produced oat flour. Furthermore, the protein content of the native grains measured by NIT correlated with the chemical composition of the oat flours. These results suggest that the properties of oat flour produced on an industrial scale, including heat treatment, could be predicted based on the properties of native oat grains.
  • Maina, Ndegwa H.; Rieder, Anne; De Bondt, Yamina; Mäkelä-Salmi, Noora; Sahlstrøm, Stefan; Mattila, Outi; Lamothe, Lisa M.; Nyström, Laura; Courtin, Christophe M.; Katina, Kati; Poutanen, Kaisa (2021)
    Daily use of wholegrain foods is generally recommended due to strong epidemiological evidence of reduced risk of chronic diseases. Cereal grains, especially the bran part, have a high content of dietary fiber (DF). Cereal DF is an umbrella concept of heterogeneous polysaccharides of variable chemical composition and molecular weight, which are combined in a complex network in cereal cell walls. Cereal DF and its distinct components influence food digestion throughout the gastrointestinal tract and influence nutrient absorption and other physiological reactions. After repeated consumption of especially whole grain cereal foods, these effects manifest in well-demonstrated health benefits. As cereal DF is always consumed in the form of processed cereal food, it is important to know the effects of processing on DF to understand, safeguard and maximize these health effects. Endogenous and microbial enzymes, heat and mechanical energy during germination, fermentation, baking and extrusion destructurize the food and DF matrix and affect the quantity and properties of grain DF components: arabinoxylans (AX), beta-glucans, fructans and resistant starch (RS). Depolymerization is the most common change, leading to solubilization and loss of viscosity of DF polymers, which influences postprandial responses to food. Extensive hydrolysis may also remove oligosaccharides and change the colonic fermentability of DF. On the other hand, aggregation may also occur, leading to an increased amount of insoluble DF and the formation of RS. To understand the structure–function relationship of DF and to develop foods with targeted physiological benefits, it is important to invest in thorough characterization of DF present in processed cereal foods. Such understanding also demands collaborative work between food and nutritional sciences.
  • Mäkelä, Jaakko Johannes; Ketoja, Elise; Kuisma, Miia T; Salo, Tapio; Yli-Halla, Markku Juhani; Kahiluoto, Helena (2019)
    Processing of organic residues may affect plant-availability of phosphorus (P) and thus the potential to recycle the nutrient, i.e., recyclability, but empirical evidence in the field is lacking. In field experiments in clay and silt loam soils with low available P, impact on P recyclability by cattle manure and sewage sludge processing methods (composting, anaerobic digestion, lime-stabilization, acid-oxidizer) and three application rates were assessed. Synthetic nitrogen (N) and potassium (K) fertilizers were supplied in surplus and NPK served as a reference. The differences in plant response were small at relevant application rates and not consistently explained by solubility of fertilizer P. Least P was required in composted manure for the same P uptake in silt loam, and composting was beneficial to plant response in clay as well. Lime-stabilization of sewage sludge had an adverse effect on P uptake in silt loam. Increasing application rates of sewage sludge hardly enhanced but did not lower P uptake or yield even at an excessive rate. Soil water-extractable P in the autumn liable to leaching was increased by NPK only. In clay soil, sewage sludges performed better than manures obviously due to anaerobic conditions caused by high precipitation, but in silt loam the contrary was the case. In conclusion, the availability of P in processed residues is more susceptible to weather and soil variables than in synthetic fertilizer. P fertilization benefits in cereal cropping in current north European conditions appear to be generally small.