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The main objective of this study was to investigate the feasibility of production of meat analogues from a faba bean protein concentrate (obtained from dry fractionation) using high-moisture extrusion (HME). The impact of the temperature, ratio between water and product feed rate and product feed rate on the physicochemical properties of the meat analogues during high-moisture extrusion (HME) was studied. The functional, textural, and sensory properties were also assessed. The impact of the moisture content was generally higher than the impact of the temperature and the feed rate within the responses evaluated. The different extrusion conditions tested did not influence the relative distribution of the oligosaccharides. Meat analogues produced with temperatures ranging between 130 and 140 °C, ratio between water and product feed rate of 4 and feed rate of 11 rpm (1.10 Kg/h) had the most positive sensory and textural properties judged by a good bite-feel (firmness) and elasticity in line with attributes associated with this product category. Of oligosaccharides analysed the content of verbascose was the highest α-galacto-oligossacharide and the content of the oligosaccharides is significant higher in the extracts of the heat-treated material compared to the starting material.

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 fraction whereas for faba beans this tendency was less pronounced. Sucrose and raffinose series oligosaccharides were higher in the coarse and fine fractions, respectively, independently on dehulling pre-treatment. A large part of the insoluble non-starch polysaccharides (NSP) was removed by dehulling and mostly assigned to cellulose. Dehulled faba beans and peas contained similar amount of total and soluble NSP, of which the latter were assigned to pectin and arabinogalactan. In general, dehulling increased the amounts of soluble NSP. Dehulling enriched phytic acid in remaining seeds and it was further enriched with protein in fine fractions. Regarding the aimed product e.g., fine fraction, dehulling gives a slight reduction of non-digestible oligosaccharides and phytic acid in peas but not in faba beans.

This chapter introduces alternative protein products as emerging ingredients in the protein industry. It starts by presenting an overview of different alternative protein sources such as land-based (pulses and cereals), microalgae, and insects. It then explains how wet and dry extraction methods are applied together with pre-treatment processes to recover protein-rich fractions (concentrates and isolates) from these sources. By the end of the chapter, a discussion on how these alternative protein products will assist the development of meat analogs, a disruptive application in the Food Industry, is presented, focusing on several studies described in the scientific literature.

Seaweed residues from Alaria esculenta, Saccharina latissima and Ascophyllum nodosum after alginate extraction have been valorized to produce cellulose-based fractions with different purification degrees. The residues were mainly composed of carbohydrates (35–57%) and proteins (12–37%), Alaria and Saccharina being richer in cellulose and Ascophyllum richer in fucoidan. The lower cellulose content in the latter made it unsuitable for the extraction of cellulosic fractions. Self-supporting films were obtained from the cellulosic fractions from Saccharina and Alaria residues. While the higher cellulose purity films presented more desirable characteristics in terms of mechanical properties (with elastic moduli of ca. 5–7 GPa and elongation values of ca. 3–5%) and visual appearance, the presence of non-cellulosic components in the films from less purified fractions reduced their water sensitivity and promoted greater water barrier (with water permeability values of ca. 4–6 kg·m/s·m2·Pa). These results point towards the potential of a simple alkaline extraction to generate cellulose-based films from seaweed residuals with the best compromise between functional properties and economical and environmental efficiency., This work was financially supported by the “Agencia Estatal de Investigación” (PCI2018-092886 Grant) and co-funded by the European Union's Horizon 2020 research and innovation programme (ERA-Net SUSFOOD2) and the RTI2018-094408-J-I00 project (MCIU/AEI/FEDER,UE).

Agar-based extracts from Gelidium sesquipedale were obtained by applying a conventional hot water treatment and alternative ultrasound- and microwave-assisted methods, with and without the application of an alkaline pre-treatment. The alkaline pre-treatment produced refined extracts with higher purity; however, extraction yields increased from 2–5% to 7–19% by omitting this step. In particular, the ultrasound-assisted extraction allowed reducing 4-fold the extraction time, while keeping constant or even increasing the yield (up to 19% for the 1 h extraction) with respect to the conventional protocol. Interestingly, the presence of proteins and polyphenols conferred the semi-refined extracts a relatively high antioxidant capacity (19–24 μmol TE/g extract). The refined extract produced by the standard protocol formed the strongest hydrogels (>1000 g/cm2). On the other hand, the semi-refined extracts produced by the alternative protocols formed slightly stronger hydrogels (337–438 g/cm2) than the refined counterparts (224–311 g/cm2), due to their greater molecular weights of the former ones. LCA assessment showed lower global warming potential for the semi-refined extracts, especially the ultrasound-assisted extraction, hence highlighting the potential of this method to produce more sustainable agar-based extracts for food-related applications., This work was financially supported by the “Agencia Estatal de Investigación” (PCI2018-092886 Grant) and co-funded by the European Union's Horizon 2020 research and innovation programme (ERA-Net SUSFOOD2).

Senior individuals can suffer from immunosenescence and novel strategies to bolster the immune response could contribute to healthy ageing. In this double-blind, randomised, controlled pilot trial, we investigated the ability of non-digestible polysaccharide (NPS) preparations to enhance the immune response in a human vaccination model. In total, 239 subjects (aged 50–79 years) were randomised to consume one of five different NPS (yeast β-glucan (YBG), shiitake β-glucan (SBG), oat β-glucan (OBG), arabinoxylan (AX), bacterial exopolysaccharide (EPS)) or control (CTRL) product daily for five weeks. After two weeks of intervention, subjects were vaccinated with seasonal influenza vaccine. The post-vaccination increases in haemagglutination inhibition antibody titres and seroprotection rate against the influenza strains were non-significantly enhanced in the NPS intervention groups compared to CTRL. Specifically, a trend towards a higher mean log2 fold increase was observed in the AX group (uncorrected p = 0.074) combined with a trend for an increased seroprotection rate, AX group (48.7%) compared to CTRL (25.6%) (uncorrected p = 0.057), for the influenza A H1N1 strain. Subjects consuming AX also had a reduced incidence of common colds compared to CTRL (1 vs. 8, p = 0.029 in Fisher exact test). No adverse effects of NPS consumption were reported. The findings of this pilot study warrant further research to study AX as an oral adjuvant to support vaccine efficacy.

While the harmonized INFOGEST model provides a physiologically relevant platform for simulated digestion, it needs to be combined with adequate analytical methods to enable quantification and comparison of protein digestibility in different food matrices. We have shown that size exclusion chromatography (SEC) can be used to estimate the proportion of small peptides potentially available for uptake. Combined with determination of total dissolved protein, the % of small peptides per total protein was calculated as a physiologically relevant estimate of protein digestibility (DSEC). Values for DSEC differed for casein (87.6%), chicken mince (72.6%), heated pea protein concentrate (67.8%), bread (63%), beef entrecote (57.7%) and pea protein concentrate (57.8%). In contrast to existing methods (TCA soluble protein, free NH2-groups), the proposed SEC based method gives separate insight into the two fundamental processes during protein digestion (solubilization and break-down), while maintaining the ability to rank digestibility of very different food proteins.

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. Fine fractions with protein contents of 44.0 and 46.2% dm from whole and dehulled peas and between 60.0 and 60.9% dm from whole and dehulled faba beans were obtained, respectively. A maximum protein recovery of 71.3% and 49.2% was obtained for peas and faba beans, respectively. Dehulling enabled a lighter colour of faba bean fractions and improved the starch enrichment in the coarse fractions from peas and faba beans. The total non-starch polysaccharides were significantly reduced in the coarse fractions when dehulling was conducted. Dehulling did not significantly improve the techno-functional properties of fine and coarse fractions. © 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

This study reports the feasibility of using Raman spectroscopy for quantification of soluble solids and individual sugars in apples. Six different commercial apple varieties were measured by Raman spectroscopy at three different steps: 1) Intact apples with skin, 2) apples without skin and 3) juices obtained from apples. Results indicated that it is possible to measure Raman signals to a depth of 8 mm into the apple with a wide area Raman probe. Multivariate calibration models were established to evaluate how well Raman spectra can be used to estimate the quality parameters SSC (%), total sugars, glucose, fructose and sucrose. Estimation accuracy for SSC was comparable with what is achievable with near-infrared spectroscopy: Root mean square error of cross-validation (RMSECV) = 0.66, 0.46 and 0.72 % and coefficients of determination (R2) = 0.70, 0.85 and 0.63 for intact apples, apples without skin and juices, respectively. Sucrose and glucose were well estimated with RMSECV of 2.8, 1.9, 2.1 mg/mL for glucose and 5.8, 3.9 and 3.7 mg/mL for sucrose, for the three sample cases, respectively. Coefficient of determination was higher than 0.82 for all models. Regression coefficients for all calibration models highlighted identifiable Raman bands that could be related to the target sugars.

Cereal beta-glucans may reduce fasting LDL-cholesterol and post-prandial blood glucose rise in humans. Several studies have shown that physicochemical properties of beta-glucan such as molecular weight (M) and solubility/extractability as well as the viscosity of food products after in vitro digestion are important for this physiological effect. In this study, we directly compare beta-glucan physicochemical properties and flow behavior of different cereal products after analytical (thermostable alpha-amylase) and physiological (in vitro digestion) extractions. The beta-glucan weight average molecular weights (Mw) were similar for both types of extractions, while differences in beta-glucan solubility between the food products were only evident after in vitro digestion. The extracts after in vitro digestion behaved essentially as pure beta-glucan solutions. Viscosity dropped to 0.8–1.2 mPa after incubation with a beta-glucanase for all extracts, but was not influenced by xylanase addition. The relationship of beta-glucan Mw (or intrinsic viscosity calculated from Mw), concentration and zero shear viscosity measured in the extracts closely resembled the general relationship reported for “random coil” polysaccharides with two distinct regions, below and above the occurrence of coil overlap. A standardized presentation of previously published in vivo data on blood glucose response showed a distinct grouping of samples with significant effect in the range of coil overlap. This points towards an important role of coil overlap for the reduction of post-prandial glycemic response by beta-glucan rich foods and demonstrates the potential of such a general comparison of different studies to increase the understanding of beta-glucan rich food products in vivo effects.

Enzymatic protein hydrolysis of food processing by-products is a well-recognized strategy for producing peptide-rich formulations of added value. The biochemical complexity of this process poses a significant challenge in the use of classical analytical methods as process monitoring tools in both laboratory and industrial setups. In the present study, we are reporting an FTIR-based multivariate approach for monitoring the change in the molecular size distribution of proteins during enzymatic hydrolysis of chicken fillets and processing by-products. For 129 protein hydrolysates, weight-average molecular weight derived from size-exclusion chromatographic analysis was established as a pragmatic measure of the extent of hydrolysis. FTIR spectra acquired from dry films of the hydrolysates were used to build multivariate calibration models using partial least squares (PLS) regression. The best predictions were obtained when the data from two different raw materials, i.e., chicken fillets and mechanical chicken deboning residues, were modeled individually. A good prediction model was also achieved for the combined data from the two raw materials using canonical PLS (CPLS) regression or variable selection. The results from the current study underline the potential of FTIR spectroscopy as a rapid analytical tool for monitoring enzymatic protein hydrolysis of complex raw materials.

Agar-based extracts from Gelidium sesquipedale were generated by heat and combined heat-sonication, with and without the application of alkali pre-treatment. Pre-treatment yielded extracts with greater agar contents; however, it produced partial degradation of the agar, reducing its molecular weight. Sonication produced extracts with lower agar contents and decreased molecular weights. A gelation mechanism is proposed based on the rheological and small angle scattering characterization of the extracts. The formation of strong hydrogels upon cooling was caused by the association of agarose chains into double helices and bundles, the sizes of which depended on the agar purity and molecular weight. These different arrangements at the molecular scale consequently affected the mechanical performance of the obtained hydrogels. Heating of the hydrogels produced a gradual disruption of the bundles; weaker or smaller bundles were formed upon subsequent cooling, suggesting that the process was not completely reversible., Synchrotron experiments were performed at NCD beamline at ALBA Synchrotron with the collaboration of ALBA staff (2018022638 project). This work was financially supported by the “Agencia Estatal de Investigación” (PCI2018-092886 Grant) and co-funded by the European Union’s Horizon 2020 research and innovation programme (ERA-Net SUSFOOD2). Part of this work was supported by the COST Action ES1408 European network for algal-bioproducts (EUALGAE).

Inhibition of dipeptidyl peptidase IV (DPP-IV) and stimulation of muscle glucose uptake are two of the key strategies for management of type-2-diabetes (T2D). In the present study, four protein hydrolysates generated by enzymatic hydrolysis of chicken by-product, i.e., mechanical chicken deboning residue, were evaluated for their DPP-IV inhibitory activity as well as their effect on glucose uptake by skeletal muscle cells. The DPP-IV inhibitory assay was performed at two concentrations (1000 μg mL−1 and 10 μg mL−1) for the crude chicken protein hydrolysates. The hydrolysate with the highest DPP-IV inhibition was selected for preparative-scale fractionation using size-exclusion chromatography (SEC). The SEC fractions were tested for DPP-IV inhibitory activity as well as their effect on glucose uptake and metabolic activity of skeletal muscle cells. The muscle cells were treated with the SEC fractions and glucose uptake was measured based on luminescence detection of 2-deoxyglucose-6-phosphate (2DG6P). A fraction with peptides in the lower molecular weight range was shown to promote glucose uptake and to inhibit DPP-IV. Further chromatographic fractionation followed by inhibition assaying of the most potent SEC fraction led to isolation of five refined peptide fractions with more than 80% DPP-IV inhibition, which were subsequently analyzed with LC-HRMS/MS. This led to identification of 14 peptides as potential DPP-IV inhibitors from protein hydrolysates of mechanical chicken deboning residue.

The objective of this study was to explore the production of an expanded snack entirely based on pea- and oat-rich fractions using the extrusion technology. The effect of the die temperature, HZ6 (146–175 °C) and blend moisture content, MC (11.2 and 16.8% dry basis) were investigated aiming at maximizing expansion, while obtaining a good texture and pleasant sensory perception. The best response was obtained with a HZ6 of 160 °C and MC of 11.2%. MC was the parameter that most influenced final extrudate properties/responses. The gross composition of the raw-material was not modified by extrusion processing apart from a decrease in glucose and fructose content attributed to Maillard reactions. The snacks contained 3.5 g of β-glucan per portion. This is high enough for both approved EFSA health claims: lowers cholesterol and reduces post-prandial glucose response.

Cereal beta-glucan can reduce post-prandial glycaemic responses, which makes it an interesting ingredient to improve the health impact of bread, a staple food with a high glycaemic index (GI). Here we compare the ability of different wheat-based breads prepared with oat bran concentrate and barley flour and a Norwegian type of soft wrap (lompe) for their ability to reduce glycaemic responses in healthy adults. Both breads with the highest beta-glucan content (3.8 g per serving) significantly reduced peak blood glucose rise (PBGR), incremental area under the blood glucose curve (iAUC) and GI compared to wheat control regardless of beta-glucan Mw and solubility. At a medium dose of 1.7 g per serving breads with beta-glucan of high MW and solubility significantly lowered iAUC, but not GI or PBGR compared to white bread. In contrast to previous studies, no significant correlation between viscosity after in vitro digestion and any of the glycaemia variables was found. However, the amount of soluble beta-glucan per serving was inversely correlated with GI. Lompe had a similar medium GI (63) than the high dose beta-glucan breads (56 and 64). However, while "lompe" had significantly lower amounts of rapidly digestible starch, no differences in in vitro starch digestion were found between the different breads. Instead, increased local viscosity at the intestinal border (e.g. soluble beta-glucan interacting with the mucus layer), dilution of nutrients (higher water content and serving size) and/or reduced gastric emptying are proposed as potential explanations for the lower glycaemic responses to high dose beta-glucan breads.

Due to their antifungal activity, chitosan and its derivatives have potential to be used for treating yeast infections in humans. However, to be considered for use in human medicine, it is necessary to control and know the chemical composition of the compound, which is not always the case for polymeric chitosans. Here, we analyze the antifungal activity of a soluble and well-defined chito-oligosaccharide (CHOS) with an average polymerization degree (DPn) of 32 and fraction of acetylation (FA) of 0.15 (C32) on 52 medically relevant yeast strains. Minimal inhibitory concentrations (MIC) varied widely among yeast species, strains and isolates (from > 5000 to < 9.77 μg mL-1) and inhibition patterns showed a time- and dose-dependencies. The antifungal activity was predominantly fungicidal and was inversely proportional to the pH, being maximal at pH 4.5, the lowest tested pH. Furthermore, antifungal effects of CHOS fractions with varying average molecular weight indicated that those fractions with an intermediate degree of polymerization, i.e. DP 31 and 54, had the strongest inhibitory effects. Confocal imaging showed that C32 adsorbs to the cell surface, with subsequent cell disruption and accumulation of C32 in the cytoplasm. Thus, C32 has potential to be used as a therapy for fungal infections.

To examine the role of realistic serving sizes of broccoli, broccoli fibre and cellulose co-consumed with mash potato, or mashed potato eaten alone, on glycaemic and insulinaemic responses (GR and IR) in healthy adults. A non-blind randomized crossover trial was conducted with thirteen healthy subjects consuming four different meals. Capillary blood samples between 0 and 180 min were analysed for glucose and insulin. The incremental area under the fasting blood glucose and insulin curves (iAUC) was calculated for different time increments. Differences in GR and IR between meals were assessed by repeated measures analysis of variance. The immediate GR and IR to one serving of mashed potato eaten with two servings of broccoli were significantly lower than mashed potato eaten alone. The peak, incremental peak and iAUC0–30min for GR and iAUC0–30min for IR were all significantly lower for the broccoli–potato meal. This meal also takes longer to return to fasting baseline with a time-delayed lag in IR and GR compared to the potato only meal. The iAUC60–120min for IR was significantly greater for the broccoli–potato meal compared to the other meals. Yet there was no corresponding significant difference between the broccoli–potato meal and the other meals for peak, incremental peak IR or any other iAUCs for GR and IR. For the potato meals containing added broccoli fibre or cellulose, no significant differences in GR or IR were observed when compared with the potato eaten alone. Co-consumption of cooked broccoli with mashed potato has a significant effect on glycaemic and insulinaemic responses compared to potato eaten alone. Our study suggests broccoli eaten with potato improves glucose homeostasis and therefore indicates a general beneficial nutritional role for broccoli when eaten with a carbohydrate staple.

The correct identification of immune-modulatory activity of polysaccharides is often hampered by immune-stimulatory contaminants, with pyrogens such as lipopolysaccharide (LPS) as a very potent example. In order to avoid false positive immuno-stimulatory properties to be attributed to polysaccharides, accurate quantification and inactivation of LPS in test samples is crucial. To quantify LPS in polysaccharide preparations of different origin and structure we used two different limulus amoebocyte lysate test kits in two different laboratories. We observed larger variation in detection of LPS contamination between kits than between labs. LPS quantification proved unreliable for some polysaccharide preparations as spike controls resulted in spike recoveries outside the acceptable range. We designed a cellular in vitro assay as alternative method to detect the presence of functional LPS. This HEK-Blue hTLR4 cell culture provides a reliable assay, when combined with a cell viability test, for determining functional LPS in polysaccharide preparations. Finally, to inactivate LPS in polysaccharide preparations, we setup an alkaline-ethanol-based treatment. With this assay we observed that our treatment (5h incubation in 0.1M NaOH) at 56°C efficiently inactivated LPS in all polysaccharide preparations below immune-stimulatory levels. At this elevated temperature, however, we also observed minimal to severe degradation of polysaccharide preparations as determined with SEC-RI. Taken together, we describe methods and precautions to reliably detect and inactivate LPS in polysaccharide preparations to allow reliable in vitro investigations towards immune-modulatory potential of polysaccharide preparations.

In this study, the use of two modern portable blood glucose monitors (PBGMs) and a fruit juice-specific system (RQFlex) from Merck was evaluated for determination of glucose concentrations in potato juice, as a representation of the whole potato. The two PBGMs (LifeScan OneTouch Ultra Easy and Bayer Contour) both provided squared correlation coefficients (R 2, p

During the production of composite wheat/barley breads β-glucans are rapidly degraded by endogenous wheat and barley flour β-glucanases. Since the physiological effect of β-glucans is related to their molecular weight a protection from degradation is essential in order to retain their full effect on the mitigation of serum cholesterol and blood glucose levels. In this study we have shortened the contact time between barley flour and water while focusing on the production of good quality barley breads. Incorporation of barley flour into already fermented wheat dough or omitting fermentation and shortening proofing times by more yeast and sucrose addition enabled the production of barley bread with increased β-glucan calcofluor weight average molecular weight (Mwcalc) and good bread quality (crumb fineness, bread slice area). The use of barley components with bigger particle size like coarse barley flour or intact barley flakes further increased β-glucan molecular weight in bread. Inactivation (with scalding) or reduction (dry heat treatment) of β-glucanase activity in barley flour prior to use, on the other hand, had little effect on β-glucan molecular weight reduction during one of the optimized short bread making processes.

Background Acetylated galactoglucomannan (AcGGM) is a complex hemicellulose found in softwoods such as Norway spruce (Picea abies). AcGGM has a large potential as a biorefinery feedstock and source of oligosaccharides for high-value industrial applications. Steam explosion is an effective method for extraction of carbohydrates from plant biomass. Increasing the reaction pH reduces the combined severity (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$R^{\prime}_{0}$$\end{document}R0′) of treatment, affecting yields and properties of extracted oligosaccharides. In this study, steam explosion was used to extract oligosaccharides from Norway spruce wood chips soaked with sodium citrate and potassium phosphate buffers with pH of 4.0–7.0. Yields, monosaccharide composition of released oligosaccharides and biomass residue, their acetate content and composition of their lignin fraction were examined to determine the impact of steam explosion buffering on the extraction of softwood hemicellulose. Results Reducing the severity of steam explosion resulted in lower yields, although the extracted oligosaccharides had a higher degree of polymerization. Higher buffering pH also resulted in a higher fraction of xylan in the extracted oligos. Oligosaccharides extracted in buffers of pH > 5.0 were deacetylated. Buffering leads to a removal of acetylations from both the extracted oligosaccharides and the hemicellulose in the residual biomass. Treatment of the residual biomass with a GH5 family mannanase from Aspergillus nidulans was not able to improve the AcGGM yields. No hydroxymethylfurfural formation, a decomposition product from hexoses, was observed in samples soaked with buffers at pH higher than 4.0. Conclusions Buffering the steam explosion reactions proved to be an effective way to reduce the combined severity (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$R^{\prime}_{0}$$\end{document}R0′) and produce a wide range of products from the same feedstock at the same physical conditions. The results highlight the impact of chemical autohydrolysis of hemicellulose by acetic acid released from the biomass in hydrothermal pretreatments. Lower combined severity results in products with a lower degree of acetylation of both the extracted oligosaccharides and residual biomass. Decrease in severity appears not to be the result of reduced acetate release, but rather a result of inhibited autohydrolysis by the released acetate. Based on the results presented, the optimal soaking pH for fine-tuning properties of extracted AcGGM is below 5.0. Electronic supplementary material The online version of this article (10.1186/s13068-018-1300-z) contains supplementary material, which is available to authorized users.

Purpose To determine the influence of meal composition on the glycaemic impact of different carbohydrate staples, and the accuracy of “adjusted calculated meal GI” compared with “measured mixed-meal GI”. Methods In a non-blind randomized crossover trial fasted healthy subjects consumed four dinner-type mixed meals of realistic serving size comprising a carbohydrate staple of either mashed potato, pasta, rice or a glucose drink, combined with fixed portions of boiled carrots, poached salmon and herb sauce. Blood samples collected between 0 and 180 min were analysed for glucose and insulin concentrations. Adjusted calculated meal GI values were determined against a 50 g reference glucose drink, and compared to corresponding measured mixed-meal GIs, supplemented with data from four previous mixed-meal postprandial glycaemic response studies. Results The common carbohydrate staples, and the glucose drink, ingested as part of the salmon mixed meal induced a significantly lower post-prandial relative glycaemic response (RGR) and concurrent higher relative insulin response than the same amount of staple eaten alone. Adjusted calculated mixed-meal GI closely predicted measured mixed-meal GI in healthy subjects for 15 out of 17 mixed meals examined, showing the need to account for effects of fat and protein when predicting measured mixed-meal GI. Further, we showed the validity of using customarily consumed food amounts in mixed-meal postprandial RGR study design. Conclusions Adjusted calculated mixed-meal GI appears a useful model to predict measured mixed-meal GI in healthy subjects and with further development and validation could aid nutrition research and rational design of healthy meals for personalized nutrition and particular consumer groups. Predicting mixed-meal measured glycaemic index in healthy subjects

Summary We have studied mixing, rheology and stability of potato-cereal flour doughs. These were prepared using samples of two varieties of cooked and cold-stored potatoes. Dependent on variety a minimum duration of 24–48 h cold-storage was required. Dough mixing torque plateau was inversely related to potato water content. This should be 2 Nm at a specific total mechanical energy input of 18–22 kJ kg−1. The resting temperature of the dough was also inversely related to its strength (plateau elastic modulus at time zero). Target dough strength should be about 25 kPa in a bob-cup. Above 15 °C it decreased as a function of time and within 1 h it became too sticky for commercial processing. At 4 °C the dough remained stable. Sufficient potato starch retrogradation is a pre-requisite to make optimal potato-cereal flour dough for commercial processing.

The relative molecular weight distribution of soluble barley beta-glucans (SBB) was monitored through the small intestine in pigs by analyzing water extracts of duodenal- and ileal digesta with HPLC-SEC. Variations among four diets, based on four different barley varieties, were documented as well as variations between animals fed the same diet. The results showed depolymerization of the SBB throughout the whole small intestine independent of diet. The average molecular weight of the SBB was reduced to approximately 50% in duodenum in all the experimental animals.

Yeast-derived beta-glucans (Y-BG) are considered immunomodulatory compounds suggested to enhance the defense against infections and exert anticarcinogenic effects. Specific preparations have received Generally Recognized as Safe status and acceptance as novel food ingredients by European Food Safety Authority. In human trials, orally administered Y-BG significantly reduced the incidence of upper respiratory tract infections in individuals susceptible to upper respiratory tract infections, whereas significant differences were not seen in healthy individuals. Increased salivary IgA in healthy individuals, increased IL-10 levels in obese subjects, beneficial changes in immunological parameters in allergic patients, and activated monocytes in cancer patients have been reported following Y-BG intake. The studies were conducted with different doses (7.5-1500 mg/day), using different preparations that vary in their primary structure, molecular weight, and solubility. In animal models, oral Y-BG have reduced the incidence of bacterial infections and levels of stress-induced cytokines and enhanced antineoplastic effects of cytotoxic agents. Protective effects toward drug intoxication and ischemia/reperfusion injury have also been reported. In conclusion, additional studies following good clinical practice principles are needed in which well-defined Y-BG preparations are used and immune markers and disease endpoints are assessed. Since optimal dosing may depend on preparation characteristics, dose-response curves might be assessed to find the optimal dose for a specific preparation.

Foods naturally high in dietary fiber are generally considered to protect against development of colorectal cancer (CRC). However, the intrinsic effect of dietary fiber on intestinal carcinogenesis is unclear. We used azoxymethane (AOM) treated A/J Min/+ mice, which developed a significantly higher tumor load in the colon than in the small intestine, to compare the effects of dietary inulin (IN), cellulose (CE) or brewers spent grain (BSG) on intestinal tumorigenesis and cecal microbiota. Each fiber was tested at two dose levels, 5% and 15% (w/w) content of the AIN-93M diet. The microbiota was investigated by next-generation sequencing of the 16S rRNA gene (V4). We found that mice fed IN had approximately 50% lower colonic tumor load than mice fed CE or BSG (p

The immune-modulating properties of fungal β-glucans have long been known, but also the structurally different cereal β-glucans have been ascribed immune-modulating properties. Since molecular weight is a crucial factor for the activity of fungal β-glucans, we investigated the effects of cereal β-glucans with different weight average molecular weights ( M ¯ w ) on two human intestinal epithelial cell lines (Caco-2 and HT-29) by monitoring cytokine secretion. Cereal β-glucan of low M ¯ w (40 kDa) increased IL-8 secretion by HT-29 cells significantly, whilst cereal β-glucans of higher M ¯ w (123–359 kDa) showed little effect on IL-8 secretion. The effect of 40 kDa cereal β-glucan on IL-8 secretion by HT-29 cells was both dose and time dependent and not due to LPS contamination. These results suggest that a number of dietary β-glucans may directly interact with some intestinal epithelial cells, resulting in moderately increased IL-8 secretion by these cells.

Phenolic contents and corresponding antioxidant activities were studied in covered whole-grain flours of Norwegian barley varieties and in two different pearling fractions. In covered whole-grain f...

High intake of dietary fiber is claimed to protect against development of colorectal cancer. Barley is a rich source of dietary fiber, and possible immunomodulatory effects of barley polysaccharides might explain a potential protective effect. Dietary fiber was isolated by extraction and enzyme treatment. A mixed-linked β-glucan (WSM-TPX, 96.5% β-glucan, Mw 886 kDa), an arabinoxylan (WUM-BS-LA, 96.4% arabinoxylan, Mw 156 kDa), a mixed-linked β-glucan rich fraction containing 10% arabinoxylan (WSM-TP) and an arabinoxylan rich fraction containing 30% mixed-linked β-glucan (WUM-BS) showed no significant effect on IL-8 secretion and proliferation of two intestinal epithelial cell lines, Caco-2 and HT-29, and had no significant effect on the NF-κB activity in the monocytic cell line U937-3κB-LUC. Further enriched arabinoxylan fractions (WUM-BS-LA) from different barley varieties (Tyra, NK96300, SB94897 and CDCGainer) were less active than the mixed-linked β-glucan rich fractions (WSM-TP and WSM-TPX) in the complement-fixing test. The mixed-linked β-glucan rich fraction from NK96300 and CDCGainer showed similar activities as the positive control while mixed‑linked β-glucan rich fractions from Tyra and SB94897 were less active. From these results it is concluded that the isolated high molecular weight mixed-linked β-glucans and arabinoxylans from barley show low immunological responses in selected in vitro test systems and thus possible anti-colon cancer effects of barley dietary fiber cannot be explained by our observations.

The aim of the current study was to evaluate the effect of a gradual substitution of wheat and soy with brewers dried grains (BDG) on pellet quality, performance, and organ weights in broiler chickens. Five diets were formulated in which 0, 10, 20, 30, or 40% BDG replaced wheat and soy, with a concomitant gradual reduction in the calculated AME level. Each of the 5 experimental diets was fed to 12-d-old broiler chickens (Ross 308) kept in 6 pens, with 12 birds/pen. The birds had ad libitum access to feed and water until termination of the experiment at d 33. Feed intake was not affected by BDG inclusion and compensatory feed intake did not occur, perhaps having been neutralized by a significant (P < 0.001) reduction in the pellet durability index. The pellet durability index was 85% in the control diet (0% BDG) and decreased significantly (P < 0.001) to 68% in the diet with 40% BDG. Increased levels of BDG reduced BW gain significantly (P < 0.001) and led to a significant (P < 0.001) increase in the feed:gain ratio. The feed:gain ratio was significantly (P < 0.05) higher in birds fed 30 and 40% BDG compared with birds fed 0, 10, and 20% BDG. The apparent ileal digestibility values of protein and energy were significantly reduced by BDG inclusion (P < 0.01 and P < 0.001, respectively), whereas starch digestibility increased significantly (P < 0.001). The relative gizzard weight increased significantly (P < 0.001), whereas the relative cecal weights were not affected by BDG inclusion. To conclude, 10 to 20% inclusion of BDG supports acceptable growth and feed utilization, and favors the development of a well-functioning gizzard.

1. A factorial (2 x 3) feeding trial was set up to investigate the effects of coarse or finely ground brewers' spent grain (BSG) and xylanase treatment, either with no xylanase, top-dressed with xylanase or pre-treated with xylanase. 2. The experimental diets shared the same basal formulation and were fed to male broiler chickens (Ross 308) housed in individual cages from 12 to 29 d of age. 3. Xylanase pre-treatment reduced the dietary concentration of arabinoxylan by 15-30%. Pellet durability increased when BSG was ground. 4. Feed utilisation was significantly higher (6%) when the birds were given coarse BSG rather than ground BSG, whereas there was no significant effect of enzyme treatment. Apparent metabolisable energy was unaffected by the dietary treatments. 5. The overall starch digestibility was high (99%), with no dietary differences, whereas ileal protein digestibility was low (57%). Xylanase top-dressing tended to improve ileal protein digestibility but, in general, xylanase treatment had no major effect on overall performance in male broilers given diets with BSG.

Freeze-dried potato samples were obtained from the varieties Saturna and Peik that had been subjected to different agronomic conditions and storage. Powdered samples originating from the same growth year were mixed with oil and heated simultaneously in a stone oven in order to study the potential for acrylamide (AA) formation in a fixed time and temperature situation. For baked samples originating from unstored potato a linear relationship was found between asparagine (Asn) and reducing sugar (RS) content and AA formation. For these samples the AA content varied linearly with a* except from samples that originally were high or low in Asn. Upon storage the correlation between the quantity of the common precursors, Asn and RS, and AA were smaller. Results of the baking experiments suggest that the AA potential for stored potato cannot be predicted from RSs and Asn alone, and that other factors that might change during storage are of importance. Due to north European conditions the RSs might not always be the limiting substrate for AA formation. Additional information for the precursor content in 2004 and 2005 are included. No systematic effect on precursor contents related to chemical vine killing was observed. Precursor contents varied among and between varieties, different cultivation years and growth sites.

A mixture of single side chains from white cabbage pectin were obtained by anion exchange chromatography after applying mild chemical conditions promoting beta-elimination. These pectin fragments were characterized by their molecular weight distribution, sugar composition, 13C-NMR, and MALDI-TOF-MS analysis. These analyses revealed that the large oligosaccharides released by beta-eliminative treatment were composed of alpha-1,5 linked arabinosyl residues with 2- and 3-linked alpha-arabinosyl side chains, and, or beta-1,4 linked galactosyl side chains. Fractions were tested for complement-fixing activity in order to determine their interaction with the complement system. These results strongly indicated that there was a minimal unit size responsible for the complement-fixing activity. Neutral pectin fragments (8 kDa) obtained from beta-elimination were inactive in the complement system, although they contained a sugar composition previously shown to be highly active. Larger pectin fragments (17 kDa) retained some activity, but much lower than polymers containing rhamnogalacturonan type 1 (RGI) structures isolated from the same source. This implied that structural elements containing multiple side chains is necessary for efficient complement-fixing activity.

In the present study, water absorption capacity (WAC) and the resulting baking performance of different barley–wheat flour blends were investigated by baking breads containing 40% barley flour. The different barley varieties varied in polysaccharide contents and composition. Knowledge about variations in WAC and its possible effects on the baking performance were gained by choosing a constant water addition. These variations were related to differences in chemical content and composition. Large variations in WAC were observed for the different barley–wheat mixtures. These variations further resulted in variations in weight, volume and form ratio of the breads. Thus, large individual differences in baking performance were observed and these differences related to differences in polysaccharide content and composition of the different barley flours. Total β-glucan content was the most important parameter for the baking performance and hence, the bread quality due to its significant contribution to the WAC.

β-Glucan content and viscosity of water-soluble β-glucans have a considerable impact on the digestion of barley. Eight different 2-row barley ( Hordeum vulgare L.) cultivars were grown in controlled environment chambers at five different temperatures until maturity. The samples were pearled, milled and analysed for their content of total, insoluble and soluble β-glucan. The water-soluble fraction was extracted at 37 °C, subjected to amylase treatment and freeze-dried. Water-soluble crude β-glucans were solubilised in distilled water, analysed for viscosity and their purity was checked by nuclear magnetic resonance. Molecular weights were profiled by size exclusion chromatography with RI detection. The content of total β-glucan varied from 4.0% to 7.4%, and was significantly affected by the growth temperature. An interaction between cultivar and growth temperature was observed for the total β-glucan content. The extractability was significantly affected by growth temperature, as there was recorded an increasing amount of water-soluble β-glucan with increasing growth temperature. Both the viscosity and the molecular weight of the water-soluble β-glucans increased with the growth temperature.

Changes in chemical quality arising from genetic composition of different barley varieties as well as non-genetic factors were investigated by comparing samples from different seasons and locations. The samples (15), consisting of different varieties originating from Norway and Canada, were analysed for polysaccharide composition as well as total protein content. The results revealed differences in chemical parameters between the hulled and hull-less varieties, especially in carbohydrate composition. Also, variations within the types were found, which indicated that factors other than the presence or lack of hull may also influence the carbohydrate composition. As expected, varieties grown at the same location in both seasons had a lesser variation in their grain composition between the growing periods than varieties grown at different locations. Changing the growth location from Canada to Norway also gave an increase in starch and insoluble fibre, but decreased the amount of β-glucan, protein an...

The purpose of this study was to isolate and perform chemical analyzes as well as biological testing of pectic material from white cabbage isolated by sequential aqueous ionic solutions (SEQAIS) or a simple pure water extraction (PW). Water extraction was aimed at yielding water-soluble pectins only, while the harsher conditions in SEQAIS aimed at extracting proto pectin as well. The pectic material resulting from the various extraction steps was characterized and tested, in order to determine whether structural and biological activity were influenced through different isolation procedures. The SEQAIS fractions obtained were one water-soluble and six partly water-soluble extracts, whereas PW yielded two water-soluble extracts. Sugar composition analysis, linkage analysis, HPSEC molecular weight distribution, HPAEC and 13 C NMR were run to obtain structural characteristics of the extracted material. Both extraction procedures resulted in degradation of pectin. Pectin containing highly methyl esterified Gal p A probably underwent β-elimination due to neutral pH during PW, while hydrolysis of Ara f occurred in the first step of SEQAIS in 50 mM acetic acid pH 4.5. Water-soluble extracts were tested for complement-fixing activity and acidic extracts with degraded side chains showed reduced activity. Authors suggest that extraction conditions at neutral pH should be used in order to withhold side chain structure and immuno-activity.

Heat-treated carbohydrate-rich foods may contain high levels of acrylamide (AA). Crisp bread is a significant dietary AA source in the Nordic countries. We studied whether urinary metabolites of AA could be candidate biomarkers of AA intake and internal dose in mice following dietary crisp bread administration or sc injection. The crisp bread was experimentally baked to contain three different concentrations of AA: 0.19, 1.02, and 2.65 mg/kg, giving dietary exposures to AA of 0.024 +/- 0.002, 0.14 +/- 0.02, and 0.29 +/- 0.04 mg/kg bodyweight (bw)/day (mean +/- SD), respectively. A linear relationship was found between dietary AA exposure and urinary AA metabolites. On average, 55% of the ingested dose was recovered as urinary AA metabolites, and the molar proportions between the urinary metabolites showed similar proportions for the different doses. Urine AA metabolites were measured after sc injection of AA at doses of 0.05, 0.5, 5, and 50 mg/kg bw, and the urinary recovery for the three lowest doses was 54%. With the highest dose, 80% was recovered in urine, and the changed pattern of urinary metabolites indicated saturation of the metabolic conversion of AA to glycidamide. These results indicate that urinary metabolites of AA are good biomarkers of AA intake and internal dose up to 5 mg/kg bw/day. After sc injection of [(14)C]AA, 92% of the radioactivity was found in the urine and 2% in feces, liver, blood, and intestinal content (6% was not detected), demonstrating that sc AA was highly systemically available, that the major part AA metabolites was excreted, and that a significant portion of urinary AA metabolites (most likely glyceramide) was not accounted for by the present analytical method. Since the urinary recovery of AA after crisp bread feeding and sc injection was practically identical, an indicative "bioavailability" of AA from crisp bread was suggested to be approximately complete.

Unacceptable hard tissue can be detected in pre-peeled potatoes after cooking. Pectin methyl esterase (PME) has been suspected to facilitate formation of Ca-bridges between pectin molecules by deesterification of the uronic acids. But this has also been questioned, due to the low storage temperature of the peeled tubers, optimum of PME being 50–70 °C. Hardness in tubers was induced by several packaging methods. Annual and seasonal variations were observed. In the work, analysis of nonstarch polysaccharides (NSP) are considered representative of the pectin content. Analyses revealed an increase in insoluble NSP during storage after peeling and cooking, and a decrease in branching (arabinose, galactose) and degree of methyl esterification of total NSP, in both fresh and cooked tissue, dependant on storage period. Reduction of steric hindrance by debranching of the pectin molecules as well as a PME-induced increase of possible Ca-cross-linking sites may favor hardening of the tissue. The microscopy does not show any pectin changes until after cooking, but the chemical data do. This suggests that hardening, at least partly, is due to the removal of methyl ester groups, as well as galactose and arabinose in the side chains. The Ca-bridges can probably not be formed until sufficient calcium is released from the starch during gelatination.

Even though size exclusion chromatography (SEC) with post column addition of calcofluor (SEC-calcofluor) has been used for the determination of cereal β-glucan molar mass in foods for many years, there is a lack of systematic evaluation of the method. To address this issue a set of suitable β-glucan standards were generated by preparative SEC and their molar mass characteristics were determined by analytical multi-detection SEC (refractive index (RI), light scattering). Each standard was then analysed by SEC-calcofluor at three different labs. As a direct comparison, the analyses were repeated with a RI detector. For SEC-calcofluor accurate measurements of weight average molar mass (Mw) can be made for β-glucan populations within 10-500×10(3)g/mol. Above this molar mass threshold there is an increasing tendency for underestimation of Mw. Precipitation of some β-glucan-calcofluor complexes may have delayed their transport into the detector.Copyright © 2015 Elsevier Ltd. All rights reserved. Inter-laboratory evaluation of SEC-post-column calcofluor for determination of the weight-average molar mass of cereal β-glucan | Request PDF. Available from: https://www.researchgate.net/publication/273507433_Inter-laboratory_evaluation_of_SEC-post-column_calcofluor_for_determination_of_the_weight-average_molar_mass_of_cereal_b-glucan [accessed Sep 18 2018].

In order to study the formation of acrylamide in potato crisps during processing, an experimental design was set up. The design variables were drying time (6 levels), frying temperature (2 levels) and frying time (8 levels). The design contained 36 samples, which were analysed for acrylamide contents using LC high-resolution mass spectroscopy (LC-HRMS), and fat contents using the Soxhlet apparatus. Prior to analysis, all potato crisp samples were ground and analysed on an NIRSystems 6500 near-infrared (NIR) spectrometer. The acrylamide contents were modelled by: (i) design variables using multiple linear regression, (ii) NIR spectra using partial least squares regression (PLSR) and (iii) design variables and NIR spectra in combination using a novel technique combining least squares regression on the former, and PLSR on the latter. The results showed that the NIR spectra alone or in combination with the design variables gave better prediction models for acrylamide than the design variables alone. This implies that the spectra contain chemical information that is not purely a result of the processing variables that were investigated in this experiment. NIR spectroscopy is proposed as a possible tool for screening and identification of potato crisps with a high acrylamide content.

Reducing sugars and free amino acids were analysed in slices from three potato cultivars before and after blanching (0–3 min). The potato crisps were deep fried at 185 °C for different times (3–8.5 min), and analysed for the concentration of acrylamide (AA) and moisture. Potato cultivar and the temperature during processing were important parameters for AA formation in potato crisps. The amount increased with an increase in the processing time. Blanching before deep-frying reduced the concentration of free asparagine and reducing sugar in the raw material. We found no effect of blanching as pretreatment on the concentration of AA in the potato crisps. Any relationship was not detected between the levels of asparagine in the different cultivars, before and after blanching, and the formation of AA in the crisp products. However, it was shown that the content of reducing sugars determined the level of AA after frying.