Barley Protein Research Articles

Correlation of Serum Tissue Transglutaminase Antibody Levels and Marsh Grading of Duodenal Biopsy in Patients of Celiac Disease

Background: Celiac disease (CD) is a chronic small intestinal immune-mediated enteropathy precipitated in genetically predisposed individuals by ingestion of wheat gluten and related proteins of barley and rye. It is an under-diagnosed gluten-sensitive enteropathy, usually presenting with atypical/extra-intestinal features. Duodenal biopsy is considered as the gold standard in the diagnosis of CD. Serum anti tissue transglutaminase (anti-tTG) antibodies is auto antibodies directed against tissue transglutaminase (tTG) enzyme. Aims and objective: The aim of the study is to find out the prevalence of CD among clinically suspected cases of malabsorption, to assess the correlation of anti-tTG levels with modified Marsh grading of duodenal biopsy, to find out sensitivity, specificity and predictive values of anti-tTG test and to calculate the cut off values of anti-tTG diagnostic of high grade CD. Methodology: The present study included 118 clinically suspected patients of malabsorption in which both duodenal biopsy and anti-tTG test was done. The mucosal damage graded according to the modified Marsh grading and anti-tTG tests were done in serum using ELISA kit. Results: The prevalence of CD among clinically suspected cases of malabsorption was 12.7%. The incidence was highest in middle aged male patients. The most common clinical symptom was chronic diarrhea and commonest presenting sign was anemia. Anti-tTG levels were found to be proportionately increasing with the severity of CD and showed a positive correlation(r=0.433). Patients with anemia and chronic diarrhea showed statistically significant (p value=0.0242 and 0.0089 respectively) mean anti-tTG levels in Celiac patients in relation to non-Celiac patients. Although the mean levels of anti-tTG was 6.3 times higher than baseline in grade 3 disease, the ROC analysis showed that anti-tTG in isolation had no significance in exactly grading the disease (AUC=0.30). Conclusion: Positive correlation was found between anti-tTG levels and modified Marsh grading. Anti-tTG showed proportionate increase with severity of duodenal damage. Anti-tTG test showed low sensitivity (42.86%) and high specificity (84.34%). Hence it is not a reliable tool in isolation to screen CD but should be used in combination with duodenal biopsy. It can be used to assess the severity of CD and for follow up.

Some aspects of application of pesticides and fertilizers on nutritive value and other characteristics of crop plants

We surveyed different aspects of the application of agrochemicals (pesticides and foliar non-standard fertilizers) on the nutritive value and other non-yield characteristics of crop plants. The survey was based on results of our own trials and studies conducted by other researchers. Various parameters of plant and seedling growth, and yield, were analyzed, as well as the chemical composition, and energetic and thermodynamic parameters of plants in order to better assess the impact of these agrochemicals on crops. The application of various agrochemicals has been found to affect the germination of seeds produced by treated plants. The most significant and most diverse results have been obtained by analyzing the yield and yield components of many different crops (field crops, fruits, vegetables), as well as their chemical composition (mineral elements, different sugars, secondary metabolites, etc.) in terms of improving their nutritive quality. It was found that in maize seedlings it occurs by changing the content of various elements, as well as polyphenol profiles and thermodynamic parameters, and the effects did not only depend on the dosage of agrochemicals but also on maize genotype. We also found that agrochemicals affected the energetic and thermodynamic parameters of individual maize plants, as well as the parameters of plant growth and yield. It was noticed that these agrochemicals greatly affected the content of microelements, starch and crude proteins in maize and barley, sugar and polyphenol contents in various fruit trees and soybean. We noted that in certain agroecological situations these agrochemicals have led to spectacular magnification of yields of different crops, but there were also situations when they did not have any positive effect on crop yield, which is discussed also in the context of results of other researchers.

Plonowanie jęczmienia jarego w warunkach nawożenia siarką

In the last 20 years, due to a significant reduction in industrial emissions and changes in the assortment of available fertilizers, a progressive sulphur deficiency has been observed in the soils of Poland and other parts of the world. This creates the need to supplement NPK fertilizers with sulphur and to conduct research on the optimization of its use as a fertilizer component. A three-year field study was carried out on Haplic Luvisols with low content of sulphur available to plants. The aim of the study was to assess the effect of sulphur-containing fertilizers (ammonium sulphate, potassium sulphate and Wigor S) applied at rates of 20 and 40 kg S/ha on the yield of grain, straw and protein of spring barley. The study showed that application of sulphur, irrespective of its form, generally significantly increased the yield of spring barley grain and straw as compared to the control. However, no significant differences were found in the effects of the fertilizers on yield depending on either the fertilizer type or application rate. Protein content in the grain of the plants fertilized with sulphate sulphur was on average about 6% higher than in the grain of non-fertilized plants. As a result of the beneficial effect of sulphur on the yield of spring barley grain and on its protein content, the protein yield increased. The highest increases were obtained following application of sulphate fertilizers, especially at a 40 kg S/ha. The research suggests that irrespective of the form used, sulphur fertilization in the conditions of deficiency of this nutrient in the soil, with relatively high temperatures and high soil moisture, significantly affects the yield of spring barley grain and straw and the accumulation of protein in the grain.

The effect of application of potassium, magnesium and sulphur on wheat and barley grain yield and protein content.

The effect of application of potassium, magnesium and sulphur on wheat and barley grain yield and protein content.

Recent advances in biosensors for diagnosis of celiac disease: A review.

Celiac disease (CD) is an intestinal issue activated by the inappropriate immune reaction towards gluten protein of wheat, rye, barley, oats, and autoantigen, tissue transglutaminase. Regardless of the accessibility of immunochemical conventions for research facility analysis of CD, there is as yet a need of speedier, less expensive, and simpler devices for diagnosing CD. This review concentrates on progresses in biosensors for diagnosing CD in perspective of the scaled down hardware, multianalyte discovery and low sample volume necessity. Various recently developed biosensors in this field are presented.

ITRAQ-based quantitative proteomic analysis of key barley proteins reveals changes after malting

Since the choice of malting varieties, as well as the impact of malting on protein composition and other malt quality parameters, are fundamental for beer production, there was a need to focus on this study. The present work was undertaken to evaluate the effect of malting processing on the barley proteins. The relationship between the protein pattern of barley grains and malt was investigated by combination of HPLC SEC separation with MS. We have found that the biggest difference between grain and malt protein profiles was observed in the fraction, where these proteins were identified: β-amylase, β-glucosidase and two various isoforms of protein Z (Z4, Z7). This peak was significantly increased after the malting. In addition, iTRAQ was applied for investigation of the relative quantitative changes of selected proteins after food technological processing. Our results indicate that the content of β-amylase is increased more rapidly in comparison to β-glucosidase. On the other hand, protein Z7 seems to have the opposite trend. The quantitative analysis reveals the increasing tendency of protein Z4 and decreasing tendency of Z7 protein after malting.

Intestinal uptake of barley protein-based nanoparticles for β-carotene delivery

Our previous study introduced a barley protein microparticle for encapsulation of hydrophobic drug/nutraceutical, which could release nanoparticles upon gastric digestion and deliver encapsulated compound to a simulated intestinal environment intact. This work focused on evaluating the potential of liberated nanoparticles to improve the absorption of encapsulated compounds (e.g., β-carotene) using in vitro Caco-2 cell and ex vivo small intestine models. Nanoparticles obtained from gastric digestion of barley protein microparticles had a spherical shape and an average size of 351 nm. Nanoparticles showed low cytotoxicity in Caco-2 cells and their cellular uptake was dependent on time, concentration and temperature. In a Caco-2 cell monolayer model, significantly greater uptake and transport of β-carotene were observed when it was delivered by nanoparticles (15%), compared to free β-carotene suspension (2.6%). In an ex vivo rat jejunum model, nanoparticles showed the capacity to retain in small intestinal tissue. Approximately 2.24 and 6.04 μg nanoparticle were able to permeate through each cm2 intestinal tissue and translocate to the serosal side after 60 and 90 min, respectively. Results from this study demonstrated the absorption improving effect of the barley protein nanoparticles and suggested their potential as vehicles for hydrophobic compounds.

Celiac disease and endocrine autoimmunity - the genetic link.

Celiac disease is a small intestinal inflammatory disease with autoimmune features that is triggered and maintained by the ingestion of the storage proteins (gluten) of wheat, barley and rye. The prevalence of celiac disease is increased in patients with monoglandular and/or polyglandular autoimmunity and their relatives. Between 10 and 30% of patients with celiac disease are thyroid and/or type 1 diabetes antibody positive, while around 5 to 7% of patients with autoimmune thyroid disease and/or type 1 diabetes are IgA anti-tissue transglutaminase antibody positive. The close relationship between celiac disease and endocrine autoimmunity is largely explained by sharing a common genetic background. The HLA antigens DQ2 (DQA1*0501-DQB1*0201) and/or DQ8 (DQA1*0301-DQB1*0302), that are tightly linked to DR3 and DR4, respectively, are the major common genetic predisposition. Moreover, functional single nucleotide polymorphisms of various genes that are involved in immune regulation have been identified as "overlap" susceptibility genes for both celiac disease and monoglandular or polyglandular autoimmunity. While plausible, it remains to be established how far a gluten free diet may prevent or ameliorate glandular autoimmunity. In conclusion, all patients with celiac disease should be screened for type 1 diabetes and/or autoimmune thyroid disease. Conversely, patients with the above autoimmune endocrine disorders should be also screened for celiac disease.

EFFECT OF BARLEY FLOUR ON WHEAT BREAD QUALITY

This study was carried out to investigate the possibility of utilization of barley flour in production of pan bread. wheat flour of (72% extract) was replaced by 10, 15 and 20% barley flour. The effect of such replacements on physical and chemical characteristics of produced pan bread were studied. The results indicated that barley flour had a higher contents of chemical composition than that in wheat flour except carbohydrate content was the highest in wheat flour (85.53%) than in barley flour (76.67%),whereas, protein, ash, dietary fiber, β-glucan and antioxidant were higher content in barley flour (13.63, 2.44, 19.00, 8.65, 97.34 respectively) as compared with its content in wheat flour (12.26, 0.49, 4.88, 0.34, 55.33 respctively),while, wet gluten and falling number were reduced by added barley in composite flour. The rheological properties of the five dough mixes were studied using farinograph and extensograph. The water absorption and dough weakening increased as the percentage of barley flour increased, while were decreased the extensibility and maximum resistance to extension . The results of sensory characteristies of prepared bread (containes10% barley flour) was not significants different from control for crust color, grain and texture. The results revealed that it was possible to use barley flour at level of 10, 15% to produce bread that satisfied baker's and consumer's sensory expectation. This levels may be to increased the nutritional value from dietary fibers, β-glucan, minerals, vitamins and antioxidants.

Microscopic and Proteomic Analysis of Dissected Developing Barley Endosperm Layers Reveals the Starchy Endosperm as Prominent Storage Tissue for ER-Derived Hordeins Alongside the Accumulation of Barley Protein Disulfide Isomerase (HvPDIL1-1).

Barley (Hordeum vulgare) is one of the major food sources for humans and forage sources for animal livestock. The average grain protein content (GPC) of barley ranges between 8 and 12%. Barley hordeins (i.e., prolamins) account for more than 50% of GPC in mature seeds and are important for both grain and flour quality. Barley endosperm is structured into three distinct cell layers: the starchy endosperm, which acts essentially as storage tissue for starch; the subaleurone, which is characterized by a high accumulation of seed storage proteins (SSPs); and the aleurone, which has a prominent role during seed germination. Prolamins accumulate in distinct, ER-derived protein bodies (PBs) and their trafficking route is spatio-temporally regulated. The protein disulfide isomerase (PDI) has been shown to be involved in PB formation. Here, we unravel the spatio-temporal proteome regulation in barley aleurone, subaleurone, and starchy endosperm for the optimization of end-product quality in barley. We used laser microdissection (LMD) for subsequent nanoLC-MS/MS proteomic analyses in two experiments: in Experiment One, we investigated the proteomes of dissected barley endosperm layers at 12 and at ≥20 days after pollination (DAP). We found a set of 10 proteins that were present in all tissues at both time points. Among these proteins, the relative protein abundance of D-hordein, B3-hordein and HvPDIL1-1 significantly increased in starchy endosperm between 12 and ≥20 DAP, identifying the starchy endosperm as putative major storage tissue. In Experiment Two, we specifically compared the starchy endosperm proteome at 6, 12, and ≥20 DAP. Whereas the relative protein abundance of D-hordein and B3-hordein increased between 6 and ≥20 DAP, HvPDIL1-1 increased between 6 and 12 DAP, but remained constant at ≥20 DAP. Microscopic observations showed that these relative protein abundance alterations were accompanied by additional localization of hordeins at the periphery of starch granules and a partial re-localization of HvPDIL1-1 from PBs to the periphery of starch granules. Our data indicate a spatio-temporal regulation of hordeins and HvPDIL1-1. These results are discussed in relation to the putative role of HvPDIL1-1 in end-product quality in barley.

A sensitive HPLC-MS/MS screening method for the simultaneous detection of barley, maize, oats, rice, rye and wheat proteins in meat products

The use of grain proteins in various types of meat products is common practice. A reliable detection of these food ingredients is required to control specifications and regarding food fraud and allergenic potential. Consequently, a sensitive HPLC-MS/MS method for the simultaneous detection of barley, maize, oats, rice, rye and wheat proteins in meat products was developed. After protein extraction and tryptic digestion, three to four selected marker peptides for each grain species were measured by HPLC-MS/MS. Emulsion-type sausages with grain-based protein concentrations in the range of 5–1000 mg/kg and blank values were produced. The limits of detection of the method were ≤5 or ≤10 mg grain protein/kg meat product for each grain species and no false-positive or -negative results were obtained. The detectability of the marker peptides only slightly decreased after storage and grilling of sausages, whereas the influence of the canning process was noticeably higher.

Evaluation of sample preparation methods for mass spectrometry-based proteomic analysis of barley leaves

BackgroundSample preparation is a critical process for proteomic studies. Many efficient and reproducible sample preparation methods have been developed for mass spectrometry-based proteomic analysis of human and animal tissues or cells, but no attempt has been made to evaluate these protocols for plants. We here present an LC–MS/MS-based proteomics study of barley leaf aimed at optimization of methods to achieve efficient and unbiased trypsin digestion of proteins prior to LC–MS/MS based sequencing and quantification of peptides. We evaluated two spin filter-aided sample preparation protocols using either sodium dodecyl-sulphate or sodium deoxycholate (SDC), and three in-solution digestion (ISD) protocols using SDC or trichloroacetic acid/acetone precipitation.ResultsThe proteomics workflow identified and quantified up to 1800 barley proteins based on sequencing of up to 6900 peptides per sample. The two spin filter-based protocols provided a 12–38% higher efficiency than the ISD protocols, including more proteins of low abundance. Among the ISD protocols, a simple one-step reduction and S-alkylation method (OP-ISD) was the most efficient for barley leaf sample preparation; it identified and quantified 1500 proteins and displayed higher peptide-to-protein inference ratio and higher average amino acid sequence coverage of proteins. The two spin filter-aided sample preparation protocols are compatible with TMT labelling for quantitative proteomics studies. They exhibited complementary performance as about 30% of the proteins were identified by either one or the other protocol, but also demonstrated a positive bias for membrane proteins when using SDC as detergent.ConclusionsWe provide detailed protocols for efficient plant protein sample preparation for LC–MS/MS-based proteomics studies. Spin filter-based protocols are the most efficient for the preparation of leaf samples for MS-based proteomics. However, a simple protocol provides comparable results although with different peptide digestion profile.

Application of Barley‐ and Lentil‐Protein Concentrates in the Production of Protein‐Enriched Doughnuts

AbstractBarley and lentil proteins have good emulsifying and foaming capacity, which make them suitable ingredients in many food formulations. The aim of this research was to develop protein‐enhanced foods based on barley and lentil proteins using doughnut as a food model. In enriched doughnut formulations, barley proteins were used to substitute for 20% of the wheat flour (doughnuts labeled as barley doughnut, barley/lentil doughnut [BLD], and vegan doughnut [VD]) and lentil proteins were used as an egg replacer (in BLD and VD doughnuts). A VD formulated with barley and lentil proteins to replace egg white protein and milk was also tested. The physicochemical parameters, proximate composition, and sensory qualities of the prepared doughnuts were studied and compared with the control doughnut (CD) containing egg white and milk. The protein‐enriched doughnuts showed better cooking characteristics with reduced cooking loss and diameter reduction compared to the control. In addition, they had a higher protein and β‐glucan content. During the storage‐stability test, the doughnuts containing lentil and barley proteins showed higher values for hardness, chewiness, and gumminess compared to the control. However, the sensory scores for appearance, flavor, and overall liking were rated more favorable toward the CD. It is also noticed that the fat content and caloric values increased for some protein‐enriched doughnut formulations. Considering the consumers’ demand of high‐protein convenient snack foods, the doughnuts prepared with barley and lentil proteins may have potential for commercialization with some improvements.

Celiac Disease and Glandular Autoimmunity.

Celiac disease is a small intestinal inflammatory disease with autoimmune features that is triggered and maintained by the ingestion of the storage proteins (gluten) of wheat, barley, and rye. Prevalence of celiac disease is increased in patients with mono- and/or polyglandular autoimmunity and their relatives. We have reviewed the current and pertinent literature that addresses the close association between celiac disease and endocrine autoimmunity. The close relationship between celiac disease and glandular autoimmunity can be largely explained by sharing of a common genetic background. Further, between 10 and 30% of patients with celiac disease are thyroid and/or type 1 diabetes antibody positive, while around 5–7% of patients with autoimmune thyroid disease, type 1 diabetes, and/or polyglandular autoimmunity are IgA anti-tissue transglutaminase antibody positive. While a gluten free diet does not reverse glandular autoimmunity, its early institution may delay or even prevent its first manifestation. In conclusion, this brief review highlighting the close association between celiac disease and both monoglandular and polyglandular autoimmunity, aims to underline the need for prospective studies to establish whether an early diagnosis of celiac disease and a prompt gluten-free diet may positively impact the evolution and manifestation of glandular autoimmunity.

Barley protein concentrates: Extraction, structural and functional properties

Protein concentrates were prepared from defatted barley (Hordeum vulgare L.) flour using alkaline and enzymatic treatments. Milder enzymatic treatments included (i) a bi-enzymatic method involving the use of starch-hydrolyzing enzymes, and (ii) a tri-enzymatic method using the former bi-enzymatic treatment followed by digestion with glucanase. The concentrate obtained through alkaline extraction (AI-BP) was comprised mainly of low molecular weight fractions of proteins. Bi-enzymatic treatment produced a protein concentrate with the highest protein content (49.0%), while those obtained by the tri-enzymatic treatment followed by an isoelectric precipitation step (TEI-BP) gave the highest protein recovery yield (78.3%). In both of the latter concentrates, 35 kDa B-hordeins were the major protein fraction. Divergence in secondary/tertiary structure elements (AI-BP; TEI-BP) was obtained and attributed to the difference in the protein profiles. Further characterization of protein concentrates indicated that they exhibit pseudoplastic behavior. Emulsifying capacity of concentrates was comparable to that of whey protein isolate.

Fortification of Al-Jameed Bouillon by Adding Barley and Wheat Bran and Study its Effect on Chemical and Sensory Properties

The aim of this study is to investigate the influence of wheat bran and barley fortification at different levels (3, 5 and 7%) on the percentage of fiber in Jameed that can reduce intestinal cholesterol absorption and other nutrients and study its effect onash, protein content and sensory attribute of this product. The results have shown that all levels of wheat bran and barley increase fiber, ash and protein percentage in Al-jameed Bouillon. The highest percentage of fiber, ash and protein were at level 7% wheat bran and for 7%barley evidence to the result, comparing with control sample. The sensory attributes were almost improved as a result of using the fiber (barley and wheat bran) at different levels.

Assessment of interaction of vanillin with barley, pea and whey proteins: Binding properties and sensory characteristics

Interactions of vanillin with barley proteins (alkaline-based & tri-enzymatic-based barley protein concentrates, AI-BP & TEI-BP) and two control proteins (pea protein concentrate, PPC; whey protein isolate, WPI) were assessed by (a) quantifying the vanillin unbound to the protein at equilibrium, (b) characterizing the structure of protein-vanillin complexes by fluorescence spectrophotometry, and (c) conducting sensory evaluation. Effects of heat- and high-pressure-treatments of proteins on these interactions were also evaluated. The interaction between vanillin and barley proteins, estimated using Klotz plots of unbound vanillin, was found to be non-cooperative, while the quenching of the protein-vanillin complex fluorescence was related to changes in protein binding site hydrophobicity upon vanillin complexation. Using unbound vanillin, native WPI showed the lowest degree of binding, while high-pressure-treated AI-BP concentrate showed the least interaction. Fluorescence spectroscopy analysis revealed the weakest vanillin interaction with heat-treated PPC, followed by heat-treated WPI. The flavor intensity perception results obtained by the sensory evaluation of high protein cookies were well correlated with those predicted by Klotz plots of unbound vanillin., while the consumers' palettes saturation results were comparable to those estimated by the fluorescence spectroscopy. Correlating analytical data with consumers’ perception contributes to the understanding of protein/flavor interactions in foods.

Novel protein-lipid composite nanoparticles with an inner aqueous compartment as delivery systems of hydrophilic nutraceutical compounds.

Food protein and lipid based nanoparticles have attracted recent interest as a means of delivering nutraceuticals. Nanoparticle encapsulation of nutraceuticals faces challenges to overcome for it to be readily applied in the food industry, such as low encapsulation efficiency for hydrophilic compounds and poor stability once in the gastrointestinal tract. This research introduces a new protein-lipid composite nanoparticle with a three-layered structure (a barley protein layer, α-tocopherol layer and phospholipid layer) and an inner aqueous compartment to load hydrophilic nutraceuticals. This delivery system showed efficient encapsulation of vitamin B12 (69%) and controlled release behavior in simulated gastrointestinal media. An in vitro cell evaluation demonstrated that nanoparticles could internalize into Caco-2 cells via energy-dependent endocytosis and significantly increase the uptake and transport efficiency of vitamin B12 in this model. In vivo, the developed vitamin B12 loaded nanoparticle showed increased serum vitamin B12 levels upon oral administration and reduced the methylmalonic acid level more efficiently than the free form in rats. A 14-day in vivo toxicity study showed no evidence of toxicity in rats implying the safety of the developed nanoparticles in long term use. Overall, the results of this study show the great potential of the developed nanoparticles in increasing the absorption of vitamin B12 upon oral administration.

Oats in healthy gluten-free and regular diets: A perspective

During the 20th century, the economic position of oats (Avena sativa L.) decreased strongly in favour of higher yielding crops including winter wheat and maize. Presently, oat represents only ~1.3% of the total world grain production, and its production system is fragmented. Nonetheless, current interest is growing because of recent knowledge on its potential benefits in food, feed and agriculture. This perspective will serve as a further impetus, with special focus on the recently valued advantages of oats in human food and health.Five approved European Food Safety Authority (EFSA) health claims apply to oats. Four relate to the oat-specific soluble fibres, the beta-glucans, and concern the maintenance and reduction of blood cholesterol, better blood glucose balance and increased faecal bulk. The fifth claim concerns the high content of unsaturated fatty acids, especially present in the endosperm, which reduces the risks of heart and vascular diseases. Furthermore, oat starch has a low glycemic index, which is favourable for weight control. Oat-specific polyphenols and avenanthramides have antioxidant and anti-inflammatory properties. Thus, oats can contribute significantly to the presently recommended whole-grain diet.Next to globulins, oats contain a small fraction of prolamin storage proteins, called ‘avenins’, but at a much lower quantity than gluten proteins in wheat, barley and rye. Oat avenins do not contain any of the known coeliac disease epitopes from gluten of wheat, barley and rye. Long-term food studies confirm the safety of oats for coeliac disease patients and the positive health effects of oat products in a gluten-free diet. These effects are general and independent of oat varieties. In the EU (since 2009), the USA (since 2013) and Canada (since 2015) oat products may be sold as gluten-free provided that any gluten contamination level is below 20ppm. Oats are, however, generally not gluten-free when produced in a conventional production chain, because of regular contamination with wheat, barley or rye. Therefore, establishing a separate gluten-free oat production chain requires controlling all steps in the chain; the strict conditions will be discussed.Genomic tools, including a single nucleotide polymorphism (SNP) marker array and a dense genetic map, have recently been developed and will support marker-assisted breeding. In 2015, the Oat Global initiative emerged enabling a world-wide cooperation starting with a data sharing facility on genotypic, metabolic and phenotypic characteristics. Further, the EU project TRAFOON (Traditional Food Networks) facilitated the transfer of knowledge to small- and medium-sized enterprises (SMEs) to stimulate innovations in oat production, processing, products and marketing, among others with regard to gluten-free. Finally, with focus on counteracting market fragmentation of the global oat market and production chains, interactive innovation strategies between customers (consumers) and companies through co-creation are discussed.

The adsorption of α-amylase on barley proteins affects the in vitro digestion of starch in barley flour

The conversion of barley starch to sugars is a complex enzymic process. Most previous work concerned the biotechnical aspect of in situ barley enzymes. However, the interactions among the macromolecular substrates and their effects on enzymic catalysis has been little examined. Here, we explore the mechanisms whereby interactions of protein and starch in barley flour affect the kinetics of enzymatic hydrolysis of starch in an in vitro system, using digestion rate data and structural analysis by confocal microscopy. The degradation kinetics of both uncooked barley flour and of purified starches are found to be two-step sequential processes. Barley proteins, especially the water-soluble component, are found to retard the digestion of starch degraded by α-amylase: the enzyme binds with water-insoluble protein and with starch granules, leading to reduced starch hydrolysis. These findings are of potential industrial value in both the brewing and food industries.