Ulla R M Holopainen

• PhD
• Senior Researcher at VTT Technical Research Centre of Finland

This study characterised the starch and dietary fibre properties and their significance to the pasting characteristics of oat flakes and flours produced from 30 Finnish pure cultivar oats with or without the industrial scale milling process. Large variation in carbohydrate characteristics was observed, the insoluble dietary fibre content of flours...

Lytic polysaccharide monooxygenases (EC1.14.99.53-56, LPMOs) are oxidative enzymes with the capability to enhance lignocellulose saccharification as well as nanofibrillation of cellulosic fibres. The parameters affecting the efficiency of oxidative modification of cotton linters and softwood kraft fibres by LPMO from Trichoderma reesei ( Tr AA9A) w...

The aim of this study was to understand the processability of thirty pure cultivar oat batches and how the physical properties of oat groats and flakes affect the characteristics of oat flake flour. This was conducted by investigating the relationship between the chemical composition of oats and the physical characteristics of oat groats, flakes an...

The impact of dehulling as a pre-treatment for dry fractionation on the distribution of inositol phosphate and the composition and quantity of different carbohydrates in the fine and coarse fractions from yellow peas and faba beans was elucidated. For peas, low molecular weight carbohydrates markedly increased during air classification in the fine...

Background: Structure and protein-starch interactions in pasta products may be responsible for lower postprandial glycemic responses compared with other cereal foods. Objective: We tested the effect on postprandial glucose metabolism induced by two pasta products, couscous and bread, through their structural changes during mastication and simula...

Faba bean (Vicia faba L.) is a potential, sustainable protein alternative. Germination behavior of Vicia faba L. var. minor and Vicia faba L. var. major needs further studies in order to enable larger scale bioprocessing. In this study, early-stage water uptake of two distinct faba bean varieties was assessed by hyperspectral imaging. Nutritional a...

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 F...

Interest in using undervalued forage fish for human consumption has recently increased due to its environmental benefits. However, feasible strategies to process the undervalued fish species to food use are limited. Therefore, this study investigated the possibility to utilise whole (ungutted) Baltic herring as a raw material for hybrid plant-fish...

Dehulling of peas and faba beans prior to milling and air classification was evaluated, namely its impact on physical properties, chemical composition and techno-functional properties of the fractions. Dry fractionation protocols for protein enrichment from whole and dehulled peas and faba beans were optimized and large-scale batches were produced....

Rice bran is an underutilized side-stream from white rice production, rich in protein and dietary fibre. The aim of the work was to study dry fractionation as a novel approach to enrich protein from non-heated, supercritical carbon dioxide–extracted milled rice bran. One-step air classification allowed protein enrichment from an original 18.5% up t...

Enzymatic modification of bleached softwood kraft fibres for improved fibre reactivity was studied at high (20% w/w) and low (1% w/w) dry matter content. The role of enzyme family and structure in fibre modification was assessed using endoglucanases from three structurally different glycoside hydrolase (GH) families (5, 7 and 45) with and without a...

This work studied the impact of bioprocessing with lactic acid bacteria starter cultures (dextran producing Weissella confusa and Lactobacillus plantarum) and proteolytic and xylanolytic enzymes on structural, chemical and sensory characteristics of wholegrain wheat crackers. Bioprocessing of flour increased free amino acids content (FAA) and water...

Hydrothermal pretreatment is commonly used for enhancing enzymatic hydrolysis of lignocellulosics. Spruce and wheat straw were pretreated with increasing severity and lignin characteristics were analysed. The effect of enzymatically isolated lignin on the hydrolysis of Avicel and the adsorption of a cellobiohydrolase onto lignin was measured. Non-p...

The aim of this study was to investigate the impact of in situ produced exopolysaccharides (EPS) on the rheological and textural properties of fava bean protein concentrate (FPC). EPS (dextrans) were produced from sucrose by two lactic acid bacteria (LAB). The acidification, rheology, and texture of FPC pastes fermented with Leuconostoc pseudomesen...

Herein, we describe a new method of assessing the kinetics of dissolution of single fibers by dissolution under limited dissolving conditions. The dissolution is followed by optical microscopy under limited dissolving conditions. Videos of the dissolution were processed in ImageJ to yield kinetics for dissolution, based on the disappearance of pixe...

Insects represent a sustainable but under-exploited food resource partly due to the chitin-containing exoskeleton and also the high lipid content that hamper the production of food ingredients. Here we present dry fractionation technology for upgrading house crickets (Acheta domesticus) and yellow mealworm larvae (Tenebrio molitor) by extraction wi...

Air classification of an industrial barley endosperm fraction with initial protein content of 8.3% mixed with Aerosil 200F flow aid resulted in protein enrichment up to 28.3% with 21.7% protein separation efficiency. By reducing the classifier wheel speed from 21500 rpm to 8000 rpm, the protein separation efficiency increased to 59.4%, whereas the...

The sustainability of the global protein production is seriously challenged, why upgrading protein from new or under-utilized sources such as brewer's spent grain (BSG) is desirable. In this article a new method for high-yield protein extraction from BSG with deep eutectic solvents (DESs) is reported. Novel carboxylate salt - urea DESs are describe...

Structural and textural properties as well as the dietary fibre content of solid cereal foams influence the oral breakdown of structure, bolus formation and digestibility. The aim of this study was to investigate how structural differences of solid cereal foams (puffs vs. flakes) affect in vivo chewing and in vitro starch digestion. Four extruded p...

The aim of the present work was to develop and evaluate near-infrared (NIR) and fluorescence spectroscopy as rapid and potential on-line methods for determination of the amount of aleurone in pearling dust fractions of barley. Phytic acid was used as marker for the aleurone layer. Different varieties of barley were pearled and dust fractions were p...

The possible use of specific biochemical compounds identified in wheat grains was evaluated for monitoring barley grain tissues during fractionation. First barley grain anatomy was studied through microscopic observation and quantification of the relative proportion of each anatomical part in four distinct barley samples from both hulled and hulles...

The Publisher regrets that this article is an accidental duplication of an article that has already been published, < http://doi.org/10.1016/j.foodres.2017.03.008 >. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdraw...

The global production of pulses, such as various peas, beans, lupins and lentils, is about 770 million tons. Pulses are diverse in their traditional food uses in Asia, Africa and America, where they have been used e.g. f.ex.in soups, spreads, meal components, snacks and breakfast items. Having high protein content (about 20-40 %), pulses have recen...

Cellulose-based filaments produced with ionic liquid-based processes have high application potential in textiles and composites to replace cotton fibres. These filaments already have unique properties that could be further improved with the addition of proteins. Keratin from poultry feathers is currently a low-value material that has potential as a...

Steam explosion was studied as a means to improve the enzymatic digestibility of carbohydrates in Brewer's spent grain, a protein and lipid-rich lignocellulosic by-product of the brewing industry. Having temperature, treatment time and the presence of acid catalyst as variables, a treatment at 200 °C for 10 min without an acid catalyst was found to...

The morphology and chemical composition of the inner bark of four willow hybrids were analyzed as a step towards complete willow biomass valorization. The inner bark consisted of highly delignified bundles of thick-walled sclerenchyma fibres and non-delignified surrounding tissue of thin-walled parenchyma cells. In comparison with willow wood fibre...

Aqueous dispersion properties of a protein concentrate obtained from turnip rapeseed (Brassica rapa) press cake were investigated. Protein content of the press cake was enriched from 35.9% to 45.8% by sequential supercritical-CO2 extraction, milling and air classification. The protein denaturation degree and the solubility in the prepared protein c...

Microscopy techniques can be utilized in studying the structure of cereal grains, their processing or end products. By stereomicroscope, the appearance of cereal samples can be recorded. For light microscopy, samples are usually fixed, embedded and cut into sections for staining with different dyes in order to visualize various components present i...

Background: Dietary recommendations for Nordic countries urge the use of plant foods as a basis for healthy nutrition. Currently, the level of dietary fibre (DF) intake is not adequate. Berries are an elementary part of the recommended Nordic healthy diet and could be consumed in higher amounts. Materials and methods: Finnish bilberries and a bi...

Wheat bran contains good quality protein, but given its location inside aleurone cells, this protein has restricted digestibility. The aim of this work was to liberate and solubilize wheat bran proteins via cell wall degradation by using carbohydrate-hydrolyzing and proteolytic enzymes without causing extensive protein hydrolysis. Bran incubated wi...

The aims were to assess how particle size reduction and carbohydrate-hydrolyzing enzyme treatment influence protein recovery from rapeseed cold-pressed cake and to determine the effect of these pretreatments in protein extraction procedures varying in ionic strength, pH, and total solid content. Defatted press cake (median particle size 600 μm) was...

Potato peel mass is a costream produced in large quantities by the food industry. Its availability and the presence of starch (46%), pectin, and cellulose make it a potential renewable raw material for polymer products. In this study, biopolymer films were produced from potato peel mass and glycerol. High-pressure homogenization (HPH) and HPH combi...

The influence of sulphur (S) application on yield formation, hordein composition and malting quality of 2-rowed spring barley (Hordeum vulgare L.) was studied in Nordic conditions for the first time. In a greenhouse experiment, S deficiency was indicated when 10 mg S/kg soil or less was available, by an increase in the malate:sulphate ratio in leav...

Two bottles of beer from an about 170 year old shipwreck (M1 Fö 403.3) near the Åland Islands in the Baltic Sea were analysed. Hop components and their degradation compounds showed that the bottles contained two different beers, one more strongly hopped than the other. The hops used contained higher levels of β-acids than modern varieties and were...

In this work, barley kernel sections embedded in resin were mapped using polarized Raman spectroscopy (PRS) for evaluation of both chemical and structural changes in endosperm upon malting. A multivariate analysis that includes Band-Target Entropy Minimization (BTEM) was used to resolve the individual spectrum of components present on sections and...

Chemical composition, baking process and structure of breads influence their degradation in digestion leading to different postprandial responses. Rye bread has a very different structure as compared to wheat bread, and rye breads are known to induce lower postprandial insulin responses than wheat bread. The aim of this study was to find out potent...

Milling properties, water uptake, and modification in malting were studied in 14 barley (Hordeum vulgare L.) lots from two consecutive crop years. In all barley lots studied, grains with lower β-glucan and protein content and higher starch content produced finer flours upon milling. Grains with lower β-glucan content also hydrated more rapidly duri...

Cell wall and pectin-degrading enzyme preparations were used to enhance extractability of proteins from rapeseed press cake. Rapeseed press cakes from cold pressing of intact Brassica rapa and partially dehulled Brassica napus seeds, containing 36-41% protein and 35-36% carbohydrates, were treated with pectinolytic (Pectinex Ultra SP-L), xylanolyti...

This work aimed to elucidate the effect of wheat aleurone integrity on its fermentability, i.e. the formation of short-chain fatty acids (SCFA) and microbial phenolic metabolites, in an in vitro model using human faecal microbiota as an inoculum. The structure of aleurone was modified by mechanical (dry grinding) or enzymatic (xylanase with or with...

Grain ultrastructure is of utmost importance when designing grain processing procedures in the food industry. In this study, wheat and barley grain components were localised using optical and Raman microscopy. The optical microscopic analyses were performed using several selective stains to localise β-glucan, protein and starch or autofluorescence...

Water-soluble biocides are prone to excessive leaching and high concentrations are therefore required in surface coatings for successful protection of a surface against biodeterioration. Encapsulation prolongs the lifetime of biocides in different matrices by protecting them from leaching and by releasing them slowly. In this study, sodium benzoate...

Reduced-fat cheese may suffer from flavour and texture problems. The improvement of such aspects using low-pressure homogenisation in a pre-processing routine in cheesemaking was investigated. Reduced- and full-fat Finnish Emmental cheeses were produced with milk homogenised at 10 MPa or without homogenisation (control), incubated and pasteurised....

Hordeins are major storage proteins of barley (Hordeum vulgare L.) grains and are considered to influence malting and brewing by forming a matrix surrounding the starch granules which affects the release of fermentable sugars. However, the extent to which environmental factors affect hordein location, and the impact of this on malting performance,...

Millions of tonnes of brewer's spent grain (BSG) are annually produced worldwide as a by-product of the brewing industry. BSG has the potential to be a valuable source of food, chemicals and energy if cost-efficient fractionation methods can be developed. A 2-fold improvement in carbohydrate solubilisation could be achieved through the introduction...

Whole grain oats contain several nutritionally advantageous constituents and many physiological responses have been linked to the intake of oat products. Most of the advantageous constituents are localized in the oat bran, which is a conventional milling product obtained from dehulled or naked oat groats by removing starchy endosperm particles. Oat...

Whole grain oats contain several nutritionally advantageous constituents and many physiological responses have been linked to the intake of oat products. Most of the advantageous constituents are localized in the oat bran, which is a conventional milling product obtained from dehulled or naked oat groats by removing starchy endosperm particles. Oat...

Four different grain cell wall staining techniques were compared. Two techniques specifically detected arabinoxylan (AX). The first technique used a xylanase probe, while the other one was based on immunolabeling of AX using monoclonal antibodies. The two other staining techniques, one based on Calcofluor and the other on immunolabeling using monoc...

Effects of a Trichoderma reesei tyrosinase (TYR) and a Trametes hirsuta laccase (LAC) on breadmaking performance of gluten-free oat flour were investigated by SDS-PAGE analysis of oat protein fractions, large deformation rheology, and microscopy of the doughs, as well as on the basis of specific volume and firmness of the gluten-free breads. TYR in...

Effects of lipid removal on the fine milling and air classification processing of oats were studied. Lipid removal by supercritical carbon dioxide (SC-CO2) extraction enabled concentration of the main components of oats – starch, protein, lipids and cell walls – into specific fractions. Using defatted oats as raw material, the highest β-glucan conc...

The waterproof defence barrier of the potato (Solanum tuberosum) tuber periderm consists of the suberized cells of phellem. The distinct polyaliphatic and polyaromatic domains of suberin have separate roles in the development of resistance to infections. The aliphatic suberin composition and changes in the amounts of peel and extractive free suberi...

A new technique to visualize cereal cell walls by fluorescence microscopy was developed. The novel staining technique is based on an inactive fluorescently labeled xylanase binding to arabinoxylan (AX), an important polysaccharide in grain cell walls in terms of the technological and physiological functionalities of grain. The xylanase probe could...

Poly(ethyleneimine) (PEI) microcapsules containing laccase from Trametes hirsuta (ThL) and Trametes versicolor (TvL) were printed onto paper substrate by three different methods: screen printing, rod coating, and flexo printing. Microcapsules were fabricated via interfacial polycondensation of PEI with the cross-linker sebacoyl chloride, incorporat...

Wheat bran is a composite material made of several layers, such as pericarp, testa and aleurone. It could be fractionated into purified fractions, which might either be used as food ingredients, or serve as a starting material for extraction of bioactive compounds. The aim of this work was to evaluate the potential of using electrostatic separation...

Wheat bran is an undervalued by-product of white flour and has great nutritional potential due to its high content in fibres and bioactive compounds. Micronized bran could be used as a food ingredient to improve the nutritional potential of cereal products, or be used as a starting material for other processes (bioactive compound extraction or bran...

Alkylresorcinols (AR) are amphiphilic phenolic compounds found in high amounts in wheat, durum wheat and rye, with different homologue composition for each cereal. The effect of different amounts of added AR from these cereals on bread volume, height, porosity and microstructure was studied. Breads with added rye bran (with high levels of AR) or ac...

240th ACS National Meeting, Division of Agriculture and food Chemistry. Boston, MA, USA, 22-26 August 2010

Wheat bran-derived arabinoxylan-oligosaccharides (AXOS) recently have been shown to potentially exert prebiotic effects. In this study, 15 bran samples obtained by milling different wheat cultivars were treated with xylanases from Hypocrea jecorina (XHJ), Aspergillus aculeatus (XAA), and Pseudalteromonas haloplanktis (XPH) to assess the effect of b...

NJF Seminar 419 Plant Breeding and Management for Human Nutrition. How can we produce more healthful crops and food products? Forssa, Finland, 10-11 June 2010

NJF Report Vol.6, 2 NJF (Nordic Association of Agricultural scientists) seminar 419. Forssa, Finland, 10-11 June 2010

International Symposium for Young Scientist and Technologists in Malting, Brewing and Distilling. Freising-Weihenstephan, Germany, 19-21 May 2010

Second International Symposium for Young Scientist and Technologists in Malting, Brewing and Distilling. Freising-Weihenstephan, Germany, 19-21 May 2010

Chemical and enzymatic depolymerizations of suberin isolated from potato peel ( Solanum tuberosum var. Nikola) were performed under various conditions. Enzymatic hydrolysis with cutinase CcCut1 and chemical methanolysis with NaOMe of suberin yielded monomeric fragments, which were identified as TMS derivatives with GC-MS and GC-FID. The solid, hydr...

This study investigated the potential of ball milling as a dry process for in situ production of arabinoxylan oligosaccharides (AXOS) in arabinoxylan (AX)-rich wheat and rye bran. An extensive lab-scale ball mill treatment (120 h, 50% jar volume capacity) increased the wheat bran water-extractable arabinoxylan (WE-AX) level from 4% (untreated bran)...

Twenty-seven barley (Hordeum vulgare L.) samples collected from growing sites in Scandinavia in 2001 and 2002 were examined to study the effect of endosperm structure on malting behavior. Samples were micromalted, and several malt characteristics were measured. Samples were classified as having a mealier or steelier endosperm on the basis of light...