Browsing by Subject "FRACTIONS"

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  • Rosa-Sibakov, Natalia; Mäkelä, Noora; Aura, Anna-Marja; Sontag-Strohm, Tuula; Nordlund, Emilia (2020)
    The objective of this work was to evaluate the role of beta-glucan molecular weight (M-w) and the presence of other carbohydrates on the physiological functionality of oat branviaanin vitrodigestion study. A complete approach using three differentin vitrodigestion models (viscosity of the small intestine digest, reduction of bile acids and on-line measurement of gas evolution) was used to predict the physiological functionality of enzymatically modified oat bran concentrate (OBC). OBC was enzymatically treated with two beta-glucanase preparations at three different levels in order to specifically decrease beta-glucanM(w)(Pure: purified beta-glucanase) or beta-glucan and other cell wall polysaccharides (Mix: commercial food-grade cell wall degrading enzyme preparation). TheM(w)of beta-glucan in OBC was tailored to high (1000 kDa), medium (200-500 kDa) and low (
  • Fouz, Ramiro; Vilar, Maria J.; Yus, Eduardo; Sanjuan, Maria-Luisa; Dieguez, Francisco J. (2016)
    The objective of this study was to investigate the variability in cow's milk somatic cell counts (SCC) depending on the type of milk meter used by dairy farms for official milk recording The study was performed in 2011 and 2012 in the major cattle area of Spain. In total, 137,846 lactations of Holstein-Friesian cows were analysed at 1,912 farms. A generalised least squares regression model was used for data analysis. The model showed that the milk meter had a substantial effect on the SCC for individual milk samples obtained for official milk recording. The results suggested an overestimation of the SCC in milk samples from farms that had electronic devices in comparison with farms that used portable devices and underestimation when volumetric meters are used. A weak positive correlation was observed between the SCC and the percentage of fat in individual milk samples. The results underline the importance of considering this variable when using SCC data from milk recording in the dairy herd improvement program or in quality milk programs.
  • Adamczyk, Bartosz; Sietio, Outi-Maaria; Biasi, Christina; Heinonsalo, Jussi (2019)
    See also the Commentary on this article by Hattenschwiler et al., 223: 5-7.
  • Xu, Yan; Pitkänen, Leena; Maina, Ndegwa Henry; Coda, Rossana; Katina, Kati; Tenkanen, Maija (2018)
    The aim of this study was to study the interactions between dextran and fava bean protein. Two dextrans produced by Leuconostoc pseudomesenteroides DSM 20193 and Weissella cibaria Sj 1b were purified and mixed with fava bean protein isolate (FPI) in water or in different buffers. The two isolated dextrans presented a typical dextran structure, mainly alpha-(1 -> 6) linkages (above 95%) and few alpha-(1 -> 3) branches, but they differed in molar mass and conformation. Dry-heating incubation of FPI and dextran mixture facilitated the conjugation of dextran to FPI through the Maillard reaction. Both mixed and conjugated systems were further heat-treated, and different influences of the formed covalent bonds on rheological properties were observed. The W. cibaria Sj 1b dextran had a much higher gel-strengthening ability than the Ln. pseudomesenteroides DSM 20193 dextran. The intermolecular FPI-dextran interactions played an important role in stabilizing the mixed systems at different pH.
  • Gurbuz, Goker; Kauntola, Vilja; Diaz, Jose Martin Ramos; Jouppila, Kirsi; Heinonen, Marina (2018)
    Interactions of food proteins and lipids under oxidative conditions may lead to alterations in food texture as well as loss of nutritional and sensory quality. Oxidative and physical stability of oil-in-water emulsions stabilized with water-soluble proteins extracted from quinoa (Chenopodium quinoa) and amaranth (Amaranthus caudatus) was monitored in an oxidation study at 30 A degrees C for 7 days. Alkaline extraction of proteins from the flours followed by acid precipitation and freeze-drying was conducted and purified rapeseed oil was used to prepare emulsions via high-pressure microfluidizer. Protein-stabilized emulsions showed lower physical and oxidative stability compared to Tween(A (R)) 20-stabilized emulsions. Lipid oxidation volatile profiles of protein-stabilized emulsions indicated advanced oxidation. Comparison with the physically more stable emulsions stored at 6 A degrees C pointed to the role of co-oxidation between proteins and lipids in coalescence of oil droplets and increase in droplet size. Emulsions stabilized with amaranth proteins showed higher resistance to oxidation compared to quinoa protein containing emulsions.
  • Jiang, Zhong-qing; Wang, Jing; Stoddard, Fred; Salovaara, Hannu; Sontag-Strohm, Tuula (2020)
    Abstract: Faba bean protein has good functionalities, but it is little used in the food industry. This study identified a challenge from unfavourable starch gelation when utilizing faba bean for producing protein-based emulsion gel foods, and developed processing methods to overcome that. Two types of protein-based emulsion gel foods, namely yogurt and tofu analogue products, were prepared. The processing methods in this study involved steps of thermal pre-treatment of the beans, dehulling, milling, adding plant oil, homogenization, prevention of starch gelation, and inducing protein gelation. Two methods for preventing starch gelation were studied, namely starch removal and hydrolysis. The gel texture, water-holding capacity, and structural properties of the gel products were evaluated. Both starch-gelation prevention methods produced yogurt and tofu analogue products having typical emulsion gel properties. Hydrolysis of starch was favourable for producing the yogurt analogue, because the hydrolysate compounds improved the gel strength and viscosity. Moreover, it utilized the whole flour, meaning all the nutrients from the cotyledon were used and no side-stream was created. In contrast, starch removal was slightly better than hydrolysis for producing the tofu analogue, because the hydrolysate lowered the gel strength and water-holding capacity of the products. It is both possible and ecologically sustainable to utilize whole faba bean flour for making emulsion gel products.
  • Karhu, Kristiina; Hilasvuori, Emmi; Jarvenpaa, Marko; Arppe, Laura; Christensen, Bent T.; Fritze, Hannu; Kulmala, Liisa; Oinonen, Markku; Pitkanen, Juha-Matti; Vanhala, Pekka; Heinonsalo, Jussi; Liski, Jari (2019)
    Most of the carbon (C) stored in temperate arable soils is present in organic matter (OM) intimately associated with soil minerals and with slow turnover rates. The sensitivity of mineral-associated OM to changes in temperature is crucial for reliable predictions of the response of soil C turnover to global warming and the associated flux of carbon dioxide (CO2) from the soil to the atmosphere. We studied the temperature sensitivity of C in <63 mu m fractions rich in mineral-associated organic matter (MOM) and of C in > 63 mu m fractions rich in particulate organic matter (POM). The fractions were isolated by physical separation of two light-textured arable soils where the C4-plant silage maize had replaced C3-crops 25 years ago. Differences in C-13 abundance allowed for calculation of the age of C in the soil-size fractions (old C, C3-C > 25 years; recent C, C4-C <25 years). We incubated bulk soils ( <2 mm) and size fractions sequentially at 6, 18, 26 and 34 degrees C (ramping up and down the temperature scale) and calculated the temperature sensitivity of old and recent C from (CO2)-C-12 and (CO2)-C-13 evolution rates. The temperature sensitivity was similar or slightly higher for POM than for MOM. Within the POM fraction, old C3-C was more sensitive to changes in temperature than recent C4-C. For the MOM fraction, the temperature sensitivity was unrelated to the age of C. Quantitative PCR analysis indicated that the proportions of bacteria, archaea and fungi did not change during incubation. Our results suggest that while OM stabilizing mechanisms affect the temperature sensitivity of soil C, temperature sensitivity appears unrelated to the age of mineral-associated OM.