Flour Matrix Research Articles

Screening of α-amylase/trypsin inhibitor activity in wheat, spelt and einkorn by high-performance thin-layer chromatography.

α-Amylase/trypsin inhibitor proteins (ATI) are discussed as possible triggers for non-celiac gluten sensitivity. The potential of high-performance thin-layer chromatography (HPTLC) was studied for the first time to analyse the inhibitory properties of ATIs from flour of wheat, spelt, and einkorn. Inhibition by each flour of the digestive enzymes trypsin or α-amylase was determined by the reduction of released metabolisation products in comparison to non-digested flour, and positive (acarbose) and negative (water) controls. Firstly, amylolysis was carried out in miniaturized form on the HPTLC surface (HPTLC-nanoGIT) after in-vial pre-incubation of the amylase with the inhibitors from flour. α-Amylase inhibition was evident via the reduction of released saccharides, as analysed by normal phase HPTLC. A strong influence of the flour matrix on the assay results (individual saccharides) was evident, caused by an increased amylolysis of further polysaccharides present, making HPTLC analysis more reliable than currently used spectrophotometric sum value assays. The detection and visualization of such matrix influence helps to understand the problems associated with spectrophotometric assays. Only maltotriose was identified as a reliable marker of the amylolysis. The highest α-amylase inhibition and thus the lowest saccharide response was detected for maltotriose in refined spelt, whereas the lowest α-amylase inhibition and thus the highest saccharide response was detected for maltotriose in refined wheat. A comparison of refined and whole grain flours showed no clear trend in the responses. Secondly, trypsin inhibition and proteolysis were performed in-vial, and any inhibition was evident via the reduction of released peptides, analysed by reversed-phase HPTLC. Based on the product pattern of the proteolysis, einkorn and whole wheat showed the highest trypsin inhibition, whereas refined wheat and refined spelt showed the lowest inhibition. Advantageously, HPTLC analysis provided important information on changes in individual saccharides or peptides, which was more reliable and sustainable than spectrophotometric in-vial assays (only sum value) or liquid column chromatography analysis (targeting only the ATI proteins).

Effects of pre-drying treatment and particle sizes on physicochemical and structural properties of pumpkin flour

The objective of this study is to investigate the effect of pre-drying treatment and particle size on pumpkin flour's compositional, functional, pasting, thermal, and structural properties. Pre-drying treatment and reducing the size of particles have led to an increase in the levels of crude fiber, phytochemicals, and functional properties. However, the amounts of moisture and lightness of color decreased with pretreatment, but improved with particle size reduction. Among the samples, those that were finely milled after pre-treatment showed the highest viscosities, while the untreated samples that were coarsely milled had lower viscosities. The pre-drying treatments yielded notable reductions in both gelatinization temperature and enthalpy of the flour matrix, in comparison to untreated flours. FTIR analysis has indicated that no new functional groups were produced. XRD analysis suggests that while pre-drying treatment leads to decreases in crystallinity index, fine milling leads to increments. The morphological pattern suggested that pretreatment effectively altered the original surface structure of the flour, but particle size reduction did not.

Extraction and Quantification of Azelaic Acid from Different Wheat Samples (Triticum durum Desf.) and Evaluation of Their Antimicrobial and Antioxidant Activities

Azelaic Acid (AzA) is a 9-carbon atom dicarboxylic acid, with numerous pharmacological uses in dermatology. Its effectiveness in papulopustular rosacea and acne vulgaris, among other dermatological disorders such as keratinization and hyper-pigmentation, is thought to be related to its anti-inflammatory and antimicrobial properties. It is a by-product of Pityrosporum fungal mycelia metabolism but also it is found in different cereals such as barley, wheat, and rye. Diverse topical formulations of AzA exist in commerce, and it is mainly produced via chemical synthesis. In this study we describe the extraction of AzA from whole grains and whole-grain flour (Triticum durum Desf.) through green methods. Seventeen different extracts were prepared and analyzed for their AzA content by HPLC-MS methods and then screened for their antioxidant activity using spectrophotometric assays (ABTS, DPPH, and Folin-Ciocalteu). Minimum-inhibitory-concentration (MIC) assays against several bacterial and fungal pathogens were performed, to validate their antimicrobial activity. The obtained results indicate that whole grain extracts provide a wider spectrum of activity than the flour matrix; in particular, the Naviglio® extract showed higher AzA content, while the hydroalcoholic ultrasound-assisted extract provided better antimicrobial and antioxidant activity. The data analysis was performed using principal component analysis (PCA), as an unsupervised-pattern-recognition technique, to extract useful analytical and biological information.

Impact of fortificants on the powder properties of a gluten-free porous starch matrix of puffed rice flour

Iron and zinc fortified pulverized expanded porous starch matrix of puffed rice (EPSMPR) flours of different particle sizes (50–150, 150–300, 300–425, 425–500, and 500–710 μm) were analyzed for powder properties and compared with un-fortified EPSMPR flours. Both fortified and control EPSMPR flour samples showed flow stability values close to 1, signifying the integrity of the flour matrix to various flow conditions. At higher rotor speed (up to 100 mm/s), no significant increase in the compaction coefficient was observed for both fortified and control EPSMPR flour of varying particle size, indicating flow speed independency. Increase in caking strength (up to 61%), water absorption capacity (up to 16%), and swelling capacity (up to 20%) of EPSMPR flour was observed with particle size. PCA analysis revealed a negative correlation between tapped and untapped densities and water absorption index: the angle between them was approximately 180°. Similarly, the angle of repose correlated negatively with the caking index.

Epitope-imprinted polydopamine and reduced graphene oxide-based sensing interface for label-free detection of gliadin

Detection of gluten and its components in foods is paramount in ensuring safety of gluten-sensitive individuals. However, the conventional immunodetection methods including gold standard enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction, and advanced proteomic methods suffer from high cost, complicated instrumentation and protocol, and slow assay turnaround time. Herein, we developed an inexpensive electrochemical sensor for gliadin (GLI) detection using electrochemically reduced graphene oxide for sensitivity enhancement and PQQPFPQQ epitope-imprinted polydopamine as selective recognition interface. The sensing performance was improved by optimizing key process factors including template/monomer ratio, pre-polymerization period, electropolymerization and electrochemical reduction cycles, elution time, and rebinding pH and time. The sensor shows a linear relationship between current response and GLI concentration in the 1–15 ppm range with high affinity to the epitope template (imprinting factor IF = 8.68) and target GLI (IF = 3.14), low limits of detection (0. 70 ppm) and quantification (2.33 ppm). The sensor also exhibits excellent selectivity against potential interferents including ovalbumin (selectivity factor SF = 0.15), folic acid (SF = 0.25), and casein (SF = 0.39) in buffered matrix. The obtained sensor-to-sensor reproducibility, repeatability, and stability ensure its sensitive determination of native GLI in rice flour matrix with coefficient of variance in the range of 2.52–4.27 %, and recovery rates of 99.1–101.9 %. The results fare better than those analyzed by traditional ELISA and similar methods. The developed sensor could be used as a reliable platform for rapid detection of allergic gluten components in processed food products.

A Quick Analysis Method for Protein Quantification in Oilseed Crops: A Comparison With Standard Protocol.

Protein is one of the most abundant substances in plants and plays a major role in human health hence standardization of its analytical quantification method is essential. Various methods for protein quantification exist, such as Kjeldahl, Bradford, Lowry, bicinchoninic acid assay (BCA), Biuret, and total amino acid content methods. These methods are widely applied; however, the development of the rapid and efficient method is the need of the time hence the objective of this research was to analyze and comparing compare the modification of the Kjeldahl method for the determination of protein content in oilseed crops. The study was performed to improve the sample preparation method (processing and digestion) for protein quantification. Generally, the method initially requires homogenization of grains to a fine flour, which involves time and increases the risk of sample cross-contamination and partial loss of oil from the sample during grinding. Moreover at times, it becomes challenging to homogenize oil seeds to fine flour due to high oil content. However, in the present research, the whole grain was digested in place of grounded flour to accomplish quick protein quantification and compared it with the flour matrix of different oil seeds. To further reduce the digestion time and avoid frothing, we have used the modified digestion mixture. The developed method was statistically validated using analysis of variance (ANOVA), Pearson correlation reliability test, paired T-test, and different types of plot analysis. The validation of the sample preparation method in protein quantification demonstrated non-significant differences that the protein content from whole grain of all the five oilseed crops shows 100% non-significant results compared with the flour matrix in both the digestion mixtures. The developed novel method could be used to prepare the sample for protein analysis and reduces the overall analysis time while ensuring the accuracy of the results.

Three‐dimensional printing of wheat flour and Acheta domesticus powder blends

SummaryThree‐dimensional printing (3DP), a novel food‐processing technique, may improve the aesthetic qualities of insect‐based products. In this study, structural and morphological properties of insect powder‐based bio‐inks with 0%–75% insect powder (IP) in wheat flour (WF) matrix were evaluated. Proximate composition, water absorption capacity, amino acids and degree of redness and yellowness increased (P < 0.05). Fourier transform infrared analysis, scanning electron microscope and 3D printability results showed good incorporation of IP and WF. Good viscoelastic properties were exhibited by the inks using 40% solid of 75% IP and 25% WF, and 50% solid of 50% IP and 50% WF. These samples showed comparable dimensions to the standard design and had good textural properties. Thus, 3DP can be effective in processing edible insects, improving the aesthetic quality and reducing consumer apathy.

Development and Characterization of Plantain (Musa paradisiaca) Flour-Based Biopolymer Films Reinforced with Plantain Fibers.

Agroindustrial wastes are a cheap and abundant source of natural fibers and macromolecules that can be used in the manufacturing of biocomposites. This study presents the development and thermo-mechanical characterization of a bio-composite film (TPF/PF), made of thermoplastic banana flour (TPF) matrix and plantain fibers (PF). Fabricated materials were characterized by physical analysis, chemical composition, Fourier-transformed spectroscopy (FTIR), thermal analysis (TGA), mechanical analysis, and scanning electronic microscopy (SEM). The physical analysis showed that TPF and PF have a low density and high affinity to water resulting in a lightweight, renewable, and biodegradable TPF/PF composite. The chemical composition and spectra analysis of the fiber showed that PF is a potential candidate for reinforcing composites due to its high α-cellulose and low lignin content. The thermal analysis determined that TPF degrades at a lower temperature than PF, therefore the matrix sets the processing temperature for TPF/PF composite films. The mechanical test showed an improvement in the tensile properties of the composite in comparison to neat TPF. Tensile strength and Young’s modulus were improved by 345% and 1196%, respectively, when PF fibers was used. Good bonding and mechanical interlocking of PF to the TPF were identified by SEM. Therefore, potential biocomposites can be developed using natural fibers and thermoplastic starches obtained from plantain agroindustrial wastes.

Ultrasonic agglomeration of model flour systems: Process parameter-product physico-thermal property relationships.

Ultrasonic compression was applied to wheat flour to create an agglomerated and compacted model food system. This novel process combines physical compression with ultrasonic vibration to permanently weld particles together, thereby producing a robust compact. Fundamental relationships among operating parameters, energy imparted to the specimens, and physical properties of the agglomerated products were developed. Integrated agglomeration energy was determined to be a linear function of percent maximum horn amplitude and ultrasonication time, and integrated energy in turn influenced product physical properties, such as density and fracture strength, in highly significant linear relationships. Microscopic, computer tomographic, and differential scanning calorimetric analyses confirmed progressive compaction of and thermal stability changes in the flour matrix with increased processing energy. Specimens agglomerated at higher energy levels were furthermore demonstrated to have higher fracture strength than conventionally (pressure-only) compressed specimens despite similar densities, due to the robust interparticle bridging produced by agglomeration. PRACTICAL APPLICATION: Ultrasonic agglomeration represents a potential improvement over standard compression in the manufacturing of meal-supplementing energy bars. Ultrasonic agglomeration effectively adheres particles together without incorporation of low-nutrient- density syrups and binders. Agglomerated and compacted products also have superior mechanical stability, which can improve texture and physical stability during product handling.

Recognizing subsurface breccias in Archean terranes: Implications for district scale metallogeny

Breccias are common in ancient and modern volcanic terranes, where they form at and below surface through volcanic, hydrovolcanic, magmatic, or tectonic mechanisms. They are critical for volcanic reconstruction as stratigraphic markers and indicators of geodynamic change and since they can be associated with mineralization their genesis is also important from an exploration perspective. Their origin can be difficult to ascertain in ancient terranes that have undergone polyphase deformation and associated metamorphism. The Joliet Breccia is a subeconomic Cu-Ag prospect within the Neoarchean Rouyn-Noranda mining district, in the Abitbi greenstone belt, Canada. It was previously interpreted as a phreatic breccia formed on the seafloor. This study presents new data indicating that the Joliet Breccia is a subsurface magmatic-hydrothermal breccia. Specifically, the recognition of gradational contacts with host rocks and between internal breccia domains, lack of sedimentary features and the spatial and temporal association with a tonalite intrusion strongly supports this interpretation. The angular, poorly sorted, lithic clasts derived from the immediate host rocks, hydrothermal cement, complete absence of a rock flour matrix, and presence of a radial and concentric fracture pattern extending into the host rocks, further support a subsurface magmatic-hydrothermal emplacement mechanism.A new TIMS U-Pb zircon age of 2698.0 ± 0.9 Ma (2σ) for a tonalite block within the breccia constrains the maximum age of brecciation. Four LA-ICP-MS U-Pb dates on hydrothermal monazite (2693.7 ± 1.0/8.9 Ma; 2696.9 ± 0.45/8.9 Ma; 2698.7 ± 1.4/8.9 Ma; 2701.2 ± 0.33/8.9 Ma; 2 s/2ssys) found in the cement of the Breccia indicate brecciation and mineralization occurred shortly after the emplacement of the tonalite. Similarly, the ca. 2697 Ma St. Jude intrusive breccia indicates a localized ca. 2699–2695 Ma magmatic-hydrothermal event superimposed on ca. 2704–2701 Ma strata. These breccias are temporally correlative with the youngest units of the Blake River Group strata and associated ca. 2698–2695 Ma volcanogenic massive sulfide (VMS) deposits, which suggests an indirect genetic link between these two hydrothermal systems. The VMS deposits may represent the near surface, distal manifestations of a deeper magmatic-hydrothermal system akin to the porphyry-intermediate sulfidation epithermal continuum in modern subaerial volcanic arcs.

3D printing of encapsulated probiotics: Effect of different post-processing methods on the stability of Lactiplantibacillus plantarum (NCIM 2083) under static in vitro digestion conditions and during storage

The increasing demand for functional foods is associated with the need to deliver probiotics through novel food matrices. In this study, a high-fiber high-protein composite flour matrix was selected as the food vehicle. To improve their stability, four encapsulation techniques (spray drying, freeze drying, spray-freeze drying, and refractance window drying) were used for the production of probiotic encapsulates in fructooligosaccharide: whey protein: maltodextrin matrix. Considering the need to develop customized/personalized products, the material supply was 3D printed using an in-house developed extrusion-based food 3D printer CARK (controlled additive-manufacturing robotic kit). The effect of four post-processing methods (freeze drying, refractance window drying, hot air drying, and microwave drying) was explored and the overall effect on probiotic stability during storage under two different conditions (4 °C and room temperature) was evaluated. No significant loss of probiotic viability was observed during the 3D printing process. Freeze drying method of post-processing achieved >90% survival rate for freeze dried and spray-freeze dried synbiotics incorporated products. Among the various treatments, spray-freeze-dried synbiotics incorporation followed by freeze drying post-processed 3D printed construct showed the best survival rate (79%) and viability (6.43 ± 0.17 log10 CFU/ml) under static in vitro digestion conditions. With around 96–98% survival rate with retained viability of 7.98 ± 0.48 log10 CFU/ml during the storage period of 35 days, the approach shows promising prospects for the delivery of probiotics in prebiotic matrices of customized shapes.

Impact of thermal processing on levels of acrylamide in a wheat‐lentil flour matrix

AbstractA growing demand for plant‐based protein has seen a resurgence in the utilisation of pulses such as lentil and chickpea as a protein‐rich substrate to produce food products traditionally based on animal or cereal protein. Additionally, pulses offer metabolic benefits due to the bioactivity of compounds including phenolic acids, simple and complex carbohydrates and a more complete amino‐acid profile which is not found in cereal grains. However, there is an increasing concern in the formation of acrylamide in food which occurs when asparagine, an abundant amino acid found in pulses, forms a complex with the reducing sugars; glucose, fructose, and maltose. Recent studies in animal models have shown that acrylamide is carcinogenic and therefore is a concern for humans. High levels of acrylamide have been reported particularly in fried products, primarily due to the Maillard reaction which amplifies the formation of acrylamide. This study investigated the levels of acrylamide in bread, cookies, and extruded products prepared with wheat‐lentil composite flour. Our research found that extrusion resulted in a significantly lower concentration of acrylamide compared to traditional baking. Additionally, increasing the amount of lentil within the composite significantly increased the net concentration of acrylamide for all bread, cookies and extrudate products.

In vitro and in vivo digestibility from bionanocomposite edible films based on native pumpkin flour/plum flour

Pumpkin (Cucurbita maxima) flour was used as an unconventional food hydrocolloid source for the development of glycerol-plasticized edible films using the casting methodology. Four film systems were made from thermoplastic pumpkin flour (TPPF) to evaluate the effect of matrix concentration (2.5% and 5%) and the addition of a natural filler (bionanocomposite - ‘huesito’ plum (Spondias purpurea) flour), maintaining the same matrix:plasticizer:nanofiller ratio. A comprehensive study in terms of the structural, thermal, crystalline, physicochemical, microstructural and mechanical properties was carried out here. These properties were related to the results obtained from the digestibility tests of the prepared edible films. This study showed that the increase in the concentration of the constituents of edible films significantly affected their properties, despite maintaining the same ratio of the constituents. A plasticizing effect was observed as a result of the increased concentration of the pumpkin flour matrix. This effect allowed obtaining more hydrophobic and plastic materials, and less digestible. It is worth noting that a new classification of resistant starch (RS) (type 6 RS) can be suggested based on the results obtained or the redefinition of the concept of type 5 RS can also be recommended. As for the effect of the addition of natural nanofiller, at a low concentration of the pumpkin flour matrix, natural nanofiller also caused a plasticizing effect. An anti-plasticizing effect was, however, determined at a high concentration of the pumpkin flour matrix. The addition of natural nanofiller in bionanocomposite films did not cause any significant effect on their digestibility.

Carbonized wood flour matrix with functional phase change material composite for magnetocaloric-assisted photothermal conversion and storage

Materials for energy collection, conversion and storage are important for overcoming energy-shortage problems. The research reported a nanocomposite containing polyethylene-glycol-10000 (PEG10000) as phase-change-material composite (PCMC) and graphene nanosheets functionalized with Fe3O4 nanoparticles (Fe3O4-GNS) stored and loaded into a porous carbonized-wood-flour (CWF) matrix. The Fe3O4-GNS/CWF/PCMC nanocomposite possessed favorable photothermal and magnetocaloric conversion properties. Introducing Fe3O4-GNS and CWF enhances the inherently low thermal conductivity of the PCMC. Energy was stored by the PCMC and released during the phase transition process. Furthermore, additional magnetothermal conversion and storage via Fe3O4-GNS component could reversely promote photothermal conversion due to continuous thermal energy supply. PEG10000 as biocompatible and nontoxic PCMC could form efficient combination within Fe3O4-GNS/CWF/PCMC and conduct least environmental-related effect. The nanocomposite exhibited favorable thermal conversion performance as temperature rising over 65 °C within 150 s, excellent thermal stability below 300 °C, a high melting enthalpy over 95 J/g and crystallization enthalpy over 85 J/g, good stability over 100 heating-cooling cycles, and efficient synergetic energy conversion. The PCMC with Fe3O4-GNS adsorbed in CWF rapidly converted light and magnetic energy to thermal energy, because of the enhanced thermal conductivity. The Fe3O4-GNS/CWF/PCMC nanocomposite therefore would have great potential in energy collecting, conversion and storage applications.

Lipid composition and dynamics during breadmaking in heat-moisture-treated associated matrices

The use of fruits, legumes, and ancient grains for bread-making applications is receiving particular attention, since they involve nutrient dense grains with proven health-promoting attributes. Dilution by 34% of the basic wheat flour matrix by accumulative ternary addition of heat-moisture-treated teff, chestnut, and chickpea flours did significantly impact both the extractability and the distribution of lipid subfractions in composite flours, doughs, and breads, and induced dynamics in lipid binding over mixing, fermentation, and baking steps. A preferential covalent lipid binding to the inside part of the starch granules takes place sequentially during bread-making steps at the expenses of both accessible free lipids and lipids initially bound non-covalently to the gluten/non-gluten proteins and to the outside part of the starch granules. Larger accumulation of starch lipids over mixing encompassed smaller extent of starch hydrolysis in fresh breads and smaller slowly digestible starch formation, while higher increase of starch lipids after fermentation and baking led to a bigger extent of starch digestibility and to a more prominent formation of slowly digestible starch fraction but to lower volume in fresh breads. Extensive binding of either protein bounded lipids or free lipids over fermentation and baking provided breads with promoted specific volume and anti-radical activity and slower retrogradation kinetics on ageing, respectively.

Evaluation of physicochemical, thermomechanical, and structural properties of chickpea flour composite films reinforced with crystalline nanocellulose

ABSTRACTChickpea flour–crystalline nano‐cellulose (CNC) composite films were prepared using chickpea flour as the film forming material, glycerol as the plasticizer and 2.5 to 10% CNC as reinforcement supplement. Mechanical properties of the composite films increased with an increase in the CNC content up to 5%. By inclusion of CNC up to 10%, the storage modulus of chickpea flour matrix increased by an order of magnitude from 7.3 to 86.4 MPa. The storage modulus of all samples, on the other hand, decreased as temperature increased. The Tg values measured by dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) were shifted toward higher temperatures by the addition of CNC. The creep resistance of chickpea flour films increased again up to 5% added CNC, and strain sweep tests confirmed the extension of linear viscoelastic region. X‐ ray diffraction (XRD) confirmed a positive correlation between the degree of crystallinity of chickpea flour composties and CNC content. FTIR spectroscopy confirmed the molecular interaction between chickpea flour, glycerol and CNC. SEM results revealed agglomeration in the structure of the film with the addition of CNC beyond 5% and diminishing of surface homogeneity, while decreasing the pore size of chickpea flour matrix. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48389.

Geographical origin discrimination of wheat kernel and white flour using near‐infrared reflectance spectroscopy fingerprinting coupled with chemometrics

SummaryWheat kernel and flour with three genotypes across 4 years procured from three different geographical areas of China were analysed using near‐infrared reflectance (NIR) spectroscopy coupled with chemometrics to better classify wheat according to the origin, production year and genotypes, respectively. For this purpose, principle component analysis‐linear discriminant analysis and multi‐way anova were applied to the NIR data. The best classification percentages were obtained for flour matrix both for geographical origin and production years with the correct percentages of 100% and 73%, respectively. For genotypes, wheat whole kernel showed better classification percentage (98.2%). All the samples were validated using external validation procedure and the obtained percentages were found satisfactory with the average prediction abilities of >85% in all regions indicating the suitability of the developed model. Multivariate anova showed that NIR fingerprints of wheat kernels and flours were significantly influenced by regions, years, genotypes and their interactions. In conclusion, white flour showed better performance in discriminating the geographical origin as compared to wheat whole kernel.

Development of a polyclonal antibody-based indirect competitive ELISA for determination of sterigmatocystin in wheat and corn flours

ABSTRACTSterigmatocystin (STC) is a toxic secondary metabolite produced by more than 50 fungal species, including Aspergillus flavus, A. parasiticus, A. nidulans, and A. versicolor. The Joint FAO/WHO Expert Committee on Food Additives concluded that sterigmatocystin is genotoxic and carcinogenic with the critical effect determined to be carcinogenicity. The present study describes a simple method to prepare hapten and immunogens in order to generate polyclonal antibodies against this metabolite. We developed a sensitive and specific polyclonal antibody-based competitive indirect enzyme-linked immunosorbent assay (ciELISA) for monitoring STC in wheat and corn flours without the need for derivatisation of STC or clean-up of samples by immunoaffinity chromatography for quantification. The half inhibitory concentration (IC50) of the established method was 4.52 ± 0.81 ng mL−1, with the limit of detection (IC10) being 0.19 ± 0.04 ng mL−1 in wheat and corn flour matrices with the coefficient of variation of less than 22%.The assay was very specific to STC and showed no cross-reactivity with its analogue structures. The ELISA allowed for up to 5% methanol without significant influence on the IC50 value. Validation of the assay was performed by spiking STC into a blank flour matrix and the recoveries were in the range of 75.3 % to 104.5 % with a coefficient of variation less than 15%. A small retail survey was conducted by purchasing wheat (n = 8) and corn flours (n = 2) from local grocery stores. All of these retail samples were negative for STC using the developed ELISA method and were confirmed by LC-MS/MS. We demonstrated a rapid, simple, and reliable method for screening STC in wheat and corn flours.

Extrusion of a Curcuminoid-Enriched Oat Fiber-Corn-Based Snack Product.

Extruded snack products were made from an oat fiber-corn flour matrix fortified with 1.5% (w/w) curcuminoids (750mg curcuminoids/100 g) to improve the solubility and stability of curcuminoids. The effects of extruder feed moisture content (21%, 28%, and 35%) and screw speed (200 and 300 rpm) on the extrusion parameters and physical properties of final snacks were investigated. Curcuminoids lost during extrusion and curcuminoids loss during subsequent drying of extrudates were analyzed, to separate the losses occurring in each unit process. Drying post extrusion (at 50°C for 4hr) was essential to obtain a crunchy shelf stable product (5% moisture). Curcuminoids loss during extrusion was from 17% to 84%, with high loss for the extrusion with low feed moisture content (21%). A further curcuminoids loss of 4% to 44% occurred during drying, with much higher loss for the extrudate with high moisture content. Total curcuminoids retained after extrusion and drying was 12% to 41% (59% to 88% loss), equivalent to 180 to 616 mg curcuminoids retained per 100 g snack, levels within recommended daily dose. Curcuminoids retained after drying was stable during 80 days of storage at 25°C. The results highlighted the importance of understanding the impact of each unit process separately (for example, extrusion and drying) on the stability of curcuminoids for the development of healthier extruded snacks. PRACTICAL APPLICATION: Extruded snacks products were developed by fortifying the snacks with oat fiber and curcuminoids in order to address the need for a healthy ready to eat food products. Some extrusion characteristics were selected to produce snack products which have favorable properties in terms of consumer acceptance.

Improved extraction of peanut residues from a wheat flour matrix for immunochemical detection

The efficacy of different buffers in extracting peanut from a solid model food incurred with peanut and subjected to processing was evaluated using two commercial ELISA kits: Veratox® for peanut allergen and peanut ELISA from Morinaga. Average percentage recoveries of peanut from unprocessed samples using the kit supplied buffers were 46 ± 5 and 28 ± 2 with the Veratox and Morinaga kits, respectively. However, Na2CO3, pH 9.6 and PBS containing 1 M GuHCl recovered 65% ± 4% and 77% ± 10% of peanut, respectively from unprocessed samples with the Veratox kit. These two buffers also performed better than the Veratox buffer with fried, high pressure processed, and baked samples. PBS containing SDS and β-ME, performed significantly better than the Morinaga buffer in recovering peanut from unprocessed, boiled and fried samples. Thus, the use of alternative extraction buffers provides better recovery of peanut residues from a processed solid food matrix.