Kernel‐based gluten contamination of gluten‐free oatmeal complicates gluten assessment as it causes binary‐like test outcomes

Gluten‐free (GF) foods, whose claim compliance is controlled at the ‘serving level’, hold better chances of protecting gluten‐intolerant consumers. This is particularly true for GF oatmeal, as oats are easily contaminated with gluten‐rich kernels of wheat, rye and barley, which remain intact to the spoon as pill‐like flakes. A single contaminant kernel in otherwise pure oats results in GF labelling noncompliance, thereby posing a risk to patients with coeliac disease. Our in‐market survey of 965 GF oatmeal servings uncovered that one in fifty‐seven servings exceeded the GF labelling maximum of 20 mg kg^?1 (i.e. 20 ppm). The noncompliance pattern was ‘binary‐like’, with kernel‐based contamination the suspected pass/fail driver. We have highlighted probabilities of misassessment for various sample sizes in light of oat's natural propensity for kernel‐based contamination and proposed use of attribute‐based sampling for compliance assessment, thereby providing a way to assess/manage/control ‘rates of servings containing a contaminant kernel’ within acceptable limits with high confidence.     

Lentil protein: a review of functional properties and food application. An overview of lentil protein functionality

There is an increased interest, driven by environmental sustainability and food security points of view, in seeking new protein sources as alternatives to replace animal proteins (Day, Trends in Food Science and Technology, 32 , 2016, 25). Pulse proteins, including lentil proteins (LP), are promising good substitutes as the wide variety of functional properties shown by them (Alsohaimy et al., World Journal of Agricultural Sciences, 3 , 2007, 123; Boye et al., Food Research International, 43 , 2010a, 537). Interest in LP has grown due to its high nutritional value, good Leu/Ile and Leu/Lys ratios (1.24–1.98 and 1.08–2.03, respectively) (Urbano et al., Lentil: An Ancient Crop for Modern Times, 2007, 47, Berlin: Springer), high digestibility (~83%) (Barbana & Boye, Food & Function, 4 , 2013, 310), and its potential use in food product applications (Farooq & Boye, Novel Food and Industrial Applications of Pulse Flours and Fractions. Pulse Foods, 1st edn, 2011, Amsterdam: Elsevier Ltd; Aider et al., Journal of Food Research, 1 , 2012, 160; De la Hera et al., LWT – Food Science and Technology, 49 , 2012, 48; Turfani et al., LWT – Food Science and Technology, 78 , 2017, 361). On the other hand, great progress has been made lately to reveal the good functionality of LP such as solubility and emulsifying, foaming and gelation capacities (Avramenko et al., Food Research International, 81 , 2016, 17; Jarpa‐Parra et al., Food Hydrocolloids, 61 , 2016, 903; Primozic et al., Food Chemistry, 237 , 2017, 65). However, the relatively unknown relationship between its molecular structure and functionalities and the lack of knowledge of the impact of the extraction and environmental conditions on those properties has hindered the exploitation of their full potential. This review describes the current knowledge of the LP structure, physical chemistry and functional properties, and its potential role as an ingredient for the development of food grade products. The gap between the current knowledge and what remains to be known is emphasised.     

Acrylamide content in potato chips on the Italian market determined by liquid chromatography tandem mass spectrometry

An easy‐to‐use and simplified liquid chromatography‐tandem mass spectrometry (LC‐ESI (+)‐MS/MS) method was adopted to determine the amount of acrylamide in thirty‐two samples of potato chips purchased on the South Italian market in 2009. Extract produced from matrices was directly analysed without derivatisation, the use of isotopically labelled acrylamide or the use of clean up cartridges. Quality analytical data were reported. The limit of detection and limit of quantification were 6 μg kg^?1 and 18 μg kg^?1, respectively and recovery values ranged from 90.7–96.3%. The relative standard deviation (RSD) ranged between 2.1% and 5.8%. The values ranged between 27 and 1400 μg kg^?1 and the arithmetic mean acrylamide content resulted 363 μg kg^?1. According to Foot et al. [Food Additives and Contaminants, 24 (2007)(S1), 37] and considering 500 μg kg^?1 as the minimum level possible with the actual available mitigation tools, the number of samples showing an acrylamide level higher than 500 μg kg^?1 resulted to be 22%. This paper gives a contribution to data collection in response to the monitoring activity of EFSA and following the Commission Recommendation 2007/331/EC: really, the number of Italian samples of potato chips and potato products for which acrylamide values was reported in the ‘results on the monitoring of acrylamide’ of EFSA ( http://www.efsa.europa.eu/cs/BlobServer/Report/datex_report_acrylamide_en,0.pdf?ssbinary=true , 2009) issued on 30 April 2009 is very limited.     

Antioxidative and reducing capacity,macroelements content and sensorial properties of buckwheat‐enhanced gluten‐free bread

Common buckwheat flour (BF) was used to substitute 10%, 20%, 30% and 40% of corn starch, the main component of a gluten‐free bread formula, to make buckwheat‐enhanced gluten‐free breads. The 40% BF‐enhanced gluten‐free bread showed the highest antioxidant capacity against ABTS⁺˙ and DPPH˙ radicals (4.1 and 2.5 μmol Trolox g^?1 DM, respectively) and reducing capacity measured by cyclic voltammetry (1.5 μmol Trolox g^?1 DM). The antioxidant and reducing capacity of buckwheat‐enhanced gluten‐free breads were positively correlated with their total phenolic contents (r = 0.97). The 40% BF‐enhanced gluten‐free bread showed the highest overall sensory quality (7.1 units) when compared to control gluten‐free bread (1.8 units). The linear relationship between applied increasing BF doses in gluten‐free bread formula and magnesium, phosphorus and potassium content in breads was noted. It was concluded that 40% BF‐enhanced gluten‐free bread could be developed and dedicated to those people suffering from coeliac disease.     

An improved method for the measurement of 3‐monochloropropanediol esters by matrix solid‐phase dispersion supported liquid–liquid extraction

3‐Monochloropropanediol (3‐MCPD) esters are contaminants produced from the high‐temperature processing of edible oils. The accurate measurement of 3‐MCPD using an easy‐to‐follow and reliable method that uses a readily available instrument is important. Here, we report an acid transesterification heptafluorobutyrylimidazole (HFBI) derivatisation method for the accurate measurement of 3‐MCPD esters in edible oils. We developed a dispersed matrix solid‐phase supported liquid–liquid extraction (DMSP‐SLE) system to remove impurities. Both the transesterification and DMSP‐SLE conditions were optimised. A good linear relationship was obtained within the range of 0.05–10 mg kg^?1 (R² ≥ 0.999) in both blank solvent and an oil sample. The limit of detection was 20.36 μg kg^?1. The average recovery of the 3‐MCPD esters spiked at 0.5, 1.0 and 2.0 mg kg^?1 into a blank oil matrix was in a range from 105.09 ± 2.77% to 120.16 ± 10.88%. The method we developed was further confirmed by performing detection on a Food Analysis Performance Assessment Scheme (FAPAS) sample.     

Characterisation of black cumin,pomegranate and flaxseed meals as sources of phenolic acids

The article focuses on the extraction of ten phenolic acids from black cumin (Nigella sativa L.), pomegranate (Punica granatum L.) and flax (Linum usitatissimum L.) seed meals. The extracts have been fractionated as free, esterified and insoluble‐bound phenolic compounds and quantitatively determined by HPLC–PDA. The analysed meals can be utilised for obtaining valuable phenolic acids. However, the distribution of phenolic compounds varies depending on the meal source. The insoluble‐bound fraction has been the richest for the black cumin meal, both qualitatively and quantitatively, containing all ten analysed phenolics. In the pomegranate meal, the main phenolic has been gallic acid, accounting for nearly 48% in free form. The esterified form of the flaxseed meal has been abundant with ferulic (1025.44 ± 3.99 mg kg^?1 dry weight), caffeic and p‐coumaric acids. The total amount of phenolic acids would be underestimated if only free fractions would be taken into account, while neglecting esterified (for the pomegranate and flax meals) and insoluble‐bound fractions (for the black cumin and pomegranate meals).     

Combined effects of matrix and gene marker on the real‐time PCR detection of wheat

DNA‐based methods have been advanced as excellent alternatives for the detection and quantification of gluten‐containing cereals. In this study, it was intended to evaluate the effect of three distinct food matrices on the performance three TaqMan real‐time PCR approaches targeting α2‐gliadin, agglutinin isolectin (Tri a 18) and thioredoxin h(Tri a 25) genes of wheat. The results of wheat flour detection in soya bean, maize and rice model matrices evidenced that sensitivity was considerably affected by both the food matrix and the target gene. Rice matrix allowed the highest sensitivity, in opposition to soya bean. The α2‐gliadin method enabled the best sensitivity, especially when combined with rice matrix (5 mg kg^?1), followed by maize (10 mg kg^?1) and soya bean (50 mg kg^?1). These findings suggest that food matrix effects need to be carefully evaluated when developing real‐time PCR assays for wheat detection/quantification, but without compromising their great effectiveness as tools to monitor gluten‐containing cereals.     

From wheat sourdough to gluten‐free sourdough: a non‐conventional process for producing gluten‐free bread

Gluten‐free (GF) sourdough was prepared from wheat sourdough and analysed both in fresh (GFS) and dried forms (DGFS). The gluten content in each GF sourdough sample was <20 mg kg^?1. The dough leavening capacity and the properties of the bread samples were investigated and compared to those of bread prepared using bakery yeast (Saccharomyces cerevisiae). Two commercial rice‐based mixtures (different for the presence/absence of buckwheat flour) were used to prepare bread samples. In GFS, lactic acid bacteria (LAB) and yeasts were found in amounts corresponding to 10⁸ and 10⁷ CFU g^?1, respectively, whereas both LAB and yeasts were detected in lower amounts (about 10⁶ CFU g^?1) in DGFS. When used in bread‐making, both GFS types produced significant dough acidification and exhibited good dough development during proofing, resulting in loaves with specific volume values between 3.00 and 4.12 mL g^?1, values similar to those obtained for reference bread (3.05÷4.15 mL g^?1). The use of GFS was effective in lowering the bread staling rate during storage for up to 7 days.     

Gluten‐free bread: multiple time–intensity analysis,physical characterisation and acceptance test

The formulation of gluten‐free breads is challenging, once the gluten network is responsible for the physical and sensory properties of bread. This study presents a novel concept for making gluten‐free breads using sugar substitutes. The quality of gluten‐free breads was analysed by means of physical (specific volume and colour), textural (firmness, elasticity and chewiness) and sensory properties (time‐intensity analysis and acceptance test). Time‐intensity analysis showed that the sample developed with raw sugar had a higher intensity of sweetness, and the sample with stevia had a higher intensity of yeast flavour. The sample with frutooligosaccharides (FOS) presented a higher acceptance by consumers. Sample with stevia presented the higher intensity of yeast flavour (8.10) and the lesser mean of specific volume (2.83 cm³.g^?1); whereas sample with sugar who presented higher intensity of sweetness stimulus (5.20) also presented the higher mean of specific volume (3.80 cm³.g^?1). The addition of prebiotic and sweetener opens up new opportunities to develop gluten‐free breads that may present similar properties to those of wheat‐based breads.     

Inorganic and Total Arsenic Contents in Rice‐Based Foods for Children with Celiac Disease

Celiac disease is an autoimmune disease that affects the villi of the small intestine causing abdominal pain, gas, diarrhea, or bad absorption due to gluten intolerance. The only treatment for this disease consists of a lifelong gluten free diet; this is, celiac people cannot consume products containing gluten, such as wheat, barley, and rye, but they can use rice and corn. Thus, rice flour is mainly used for the manufacturing of the basic products of this population. Unfortunately, rice can contain high contents of total (t‐As) and inorganic (i‐As) arsenic. The current study demonstrated that products for celiac children with a high percentage of rice contained high concentrations of arsenic (256 and 128 μg kg^?1). The daily intake of i‐As ranged from 0.61 to 0.78 μg kg^?1 body weight (bw) in children up to 5 y of age; these values were below the maximum value established by the EFSA Panel (8.0 μg kg^?1 bw per day), but it should be considered typical of populations with a high exposure to this pollutant. Finally, legislation is needed to improve the labeling of these special rice‐based foods for celiac children; label should include information about percentage, geographical origin, and cultivar of the used rice.     

Cooking and texture properties of gluten‐free fettuccine processed from defatted flaxseed flour and rice flour

Nonconventional raw materials have been applied in gluten‐free pasta, to meet the demand of people with coeliac disease. The objective of this study was to evaluate the cooking properties and texture of pasta formulated with rice flour, defatted flaxseed flour and pregelatinised mixed flour of rice and flaxseed (80:20). For this experiment, simplex design was used. Cooking properties and texture were found within the quality limits established for this type of product. The pasta with the most desirable properties (short optimum cooking time (OCT), less solid loss (SL) and intermediate mass increase (MI)) was that one formulated with 43 g 100 g^?1 of pregelatinised flour, 47 g 100 g^?1 of rice flour and 10 g 100 g^?1 of defatted flaxseed flour. This formulation can be characterised as a food rich in dietary fibre and of high nutritional value.     

Enrichment of fresh pasta with antioxidant extracts obtained from artichoke canning by‐products by ultrasound‐assisted technology and quality characterisation of the end product

This work is aimed at: (i) analysing the extracts obtained from canning by‐products of three artichoke cultivars (Opal, Capriccio and Catanese) for antioxidant parameters; (ii) comparing UHPLC‐ESI‐MS/MS profile, colour, textural properties and cooking performance of fresh pasta enriched of the most antioxidant extract, with control pasta. The concentrated Catanese cv. extracts showed the highest antioxidant activity (1662 μmol Trolox equivalents L^?1) and the highest levels of luteolin‐7‐O‐rutinoside, luteolin‐7‐O‐glucoside and apigenin‐7‐O‐rutinoside compared to other cultivars. Fresh pasta enriched of Catanese extract showed higher (P < 0.05) phenolic compounds and antioxidant activity (500 mg gallic acid kg^?1 and 1324 μmol Trolox kg^?1, respectively) than control pasta (306 mg gallic acid kg^?1 and 886 μmol Trolox kg^?1, respectively). The extract increased (P < 0.05) pasta brownness (from 19.93 to 23.34), and decreased yellowness (from 27.11 to 23.09), but did not alter textural and cooking parameters. So, pasta was a good vehicle to increase the antioxidant dietary intake.     

In vitro inhibitory effects of cranberry bean (Phaseolus vulgaris L.) extracts on aldose reductase, α‐glucosidase and α‐amylase

The in vitro inhibitory activities of different seed extracts prepared from cranberry bean mutant SA‐05 and its wild‐type variety Hwachia against aldose reductase, α‐glucosidase and α‐amylase were examined. The results indicated that the polyphenolics‐rich extracts obtained using 800 g kg^?1 methanol and 500 g kg^?1 ethanol demonstrated inhibitory activities against aldose reductase (IC₅₀ of 0.36–0.46 mg mL^?1) and α‐glucosidase (IC₅₀ of 1.32–1.94 mg mL^?1). The 500 g kg^?1 ethanol extracts also showed α‐amylase inhibitory activities (IC₅₀ of 70.11–80.22 μg mL^?1). Subsequent extracts, prepared further with NaCl and H₂O from precipitates of 800 g kg^?1 methanol or 500 g kg^?1 ethanol extracts, exhibited potent α‐amylase inhibitory activities (IC₅₀ of 17.68–38.68 μg mL^?1). A combination of 500 g kg^?1 ethanol extraction plus a subsequent H₂O extraction produced highest polyphenolics and α‐amylase inhibitors. The SA‐05 α‐amylase inhibitor extracts showed greater inhibitory activities than that of Hwachia. Thus, cranberry bean mutant SA‐05 is an advantageous choice for producing anti‐hyperglycaemic compounds.     

Microwave drying of mango ginger (Curcuma amada Roxb): prediction of drying kinetics by mathematical modelling and artificial neural network

Curcuma amada (Mango ginger) was dried at four different power levels ranging 315–800 W to determine the effect of microwave power on moisture content, moisture ratio, drying rate, drying time and effective diffusivity. Among the fifteen thin layer drying models considered for evaluating the drying behaviour, the semi‐empirical Midilli et al., model described the drying kinetics very well with R² > 0.999. Drying rate and effective diffusivity increased as the microwave power output increased. Activation energy was estimated by a modified Arrhenius type equation and found to be 21.6 kW kg^?1. A feed‐forward artificial neural network using back‐propagation algorithm was also employed to predict the moisture content during MW drying and found adequate to predict the drying kinetics with R² of 0.985.     

Koji fermentation based on extracellular peptidases of <Emphasis Type="Italic">Flammulina velutipes</Emphasis>

A total of 28 basidiomycetes and 16 substrates were investigated to detect extracellular peptidases for the hydrolysis of wheat gluten as a complex Koji substrate. In a first screening, basidiomycetes were grown in submerged cultures containing gluten as only carbon and nitrogen source. Growth rate, protein concentration and peptidase activity were monitored. Flammulina velutipes, Armillaria mellea, Trametes versicolor, Meripilus giganteus, Fomitopsis pinicola, Phanerochaete chrysosporium and Hericium erinaceus showed high peptidase activity. To evaluate the effects of complex substrates on peptidase generation, a set of experiments was performed using surface cultures of Flammulina velutipes. This fungus grew well on many of the substrates and yielded a maximum of over 160.000 arbitrary U mL⁻¹ on the surface liquid released from gluten pellets. Gelatin zymography visualized a complex mixture of secreted peptidases. Highest peptidase yield was obtained from a koji-type culture: A maximum of 63% of the gluten was converted to free amino acids in 14 days by peptidase activities in the range of 80,000–90,000 aU mL⁻¹. The dark brown hydrolysate smelled and tasted like meat broth with no detectable bitterness.     

Antioxidant potential of protein‐rich serum from farmed swan goose (Anser cygnoides): in vitro and in vivo evaluation of antioxidant effects

As food ingredient, Anser cygnoides is farmed in large scale; however, its blood is underused. The characteristics, stability and antioxidant activities of P owder of farmed C ygnoides S erum (FACSP) were investigated. Results showed that FACSP was protein‐rich and displayed satisfactory antioxidant activities. In vitro analysis indicated that the IC₅₀ values of 2, 2′‐azinobis‐(3‐ethylbenz‐thiazoline‐6‐sulphonate), 1,1‐diphenyl‐2‐picrylhydrazyl and hydroxyl radicals were 1.56, 2.76 and 39.55 mg mL^?1, respectively. In vivo experiment showed that the activity of total superoxide dismutase and content of glutathione of the FACSP‐treated groups were enhanced, and the contents of malondialdehyde and protein carbonyl were decreased. The parameters of 400 and 800 mg kg^?1 bw day^?1 dose groups were equally or approximately to vitamin C. The FACSP shows potential as an antioxidant functional food at a dose of 400 mg kg^?1 bw day^?1.     

Studies on protein and its high‐molecular‐weight subunit composition in relation to chapati‐making quality of Indian wheat cultivars

In order to predict the suitability of wheat for chapati making, 15 Indian wheat cultivars were studied for various protein characteristics in relation to chapati‐making quality. The cultivars varied considerably in their protein characteristics and chapati‐making potential. Results clearly indicated that both quantitative and qualitative characteristics of proteins influenced the chapati‐making potential of cultivars. Puffed height, the important qualitative parameter of chapati, was positively correlated with protein content (r = 0.62, p < 0.05), gluten content (r = 0.79, p < 0.01), sodium dodecyl sulphate (SDS) sedimentation value (r = 0.57, p < 0.05) and Glu‐1 quality scores of high‐molecular‐weight (HMW) subunits (r = 0.66, p < 0.01). Overall quality score of chapati was positively correlated with gluten content (r = 0.64, p < 0.01), SDS sedimentation value (r = 0.60, p < 0.05) and Glu‐1 score (r = 0.58, p < 0.05). HMW subunit composition varied considerably among cultivars. Cultivars having 5 + 10 subunits at the Glu‐1D chromosome, a protein content of about 130 g kg^?1 and SDS sedimentation value around 75 ml yielded excellent chapatis, while those having 2 + 12 subunits, a protein content of about 115 g kg^?1 and SDS sedimentation value around 55 ml resulted in poor chapatis. Interestingly, the presence of the 1BL/1RS chromosome in cultivars had no adverse effect on chapati quality. © 2003 Society of Chemical Industry     

Cyanogenic potential of fresh and frozen cassava on retail sale in three Irish cities: a snapshot survey

Imported cassava roots can be found on retail sale in several Irish cities and towns. Fresh roots (n = 36 roots) and peeled frozen root pieces (n = 28 packs) were randomly purchased from five retailers in Belfast, Dublin and Limerick and assayed for cyanogenic potential (CNp). Total CNp of fresh root parenchyma varied from 37.5 to 242.9 mg kg^?1 as HCN, dry weight basis – dwb), averaging 104.4 mg kg^?1 HCN (dwb). Total CNp of frozen root parenchyma (n = 28 packs) ranged from 28.5 to 258.6 mg kg^?1 HCN (dwb), averaging 81.7 mg kg^?1 HCN (dwb). Around 78% of fresh roots, and 93% of packs of frozen parenchyma, complied with the Codex Alimentarius definition of ‘sweet’ cassava, but most (86.1% and 64.3%, respectively) exceeded European Union NETTOX recommendations for total CNp. In around one‐third of frozen parenchyma packs, nonglycosidic cyanogens accounted for 83–100% of total CNp. The toxicological implications are briefly discussed.