Developing gluten free bakery improvers by hydrothermal treatment of rice and corn flours

The impact of hydrothermal treatment of rice and corn flours on their potential as gluten free bakery improvers was tested. Hydrothermal treatment of flours was carried out by suspending flours in water on the basis of 5/1 (w/w) and heated until 65 °C. Corn or rice semolina supplemented by field bean semolina in ratio of 2/1 (w/w) were used for obtaining protein enriched gluten free breads, where improvers functionality was tested. Two central composite designs involving water hydration levels (X1, X′1) and the level of hydrothermally treated rice or corn flours (X2, X′2) were used. Instrumental analyses of breads (specific volume, moisture content, crumb texture and height/width ratio) were carried out to assess the impact of experimental factors. Results showed that hydrothermal treatment of rice or corn flours affected in different extent the bread properties, increasing the specific volume of breads and H/W ratio, and decreasing the hardness and chewiness of both types of breads. The optimum formulation for rice/field bean bread contained 7.59 g/100 g treated rice flour and 96.66 g/100 g water, and for corn/field bean bread the optimum included 4.73 g/100 g treated corn and 78.81 g/100 g water. Optimized breads were found acceptable according to color and texture structure.Financial support of Spanish Scientific Research Council (CSIC), the Spanish Ministry of Economy and Sustainability (Project AGL2014-52928-C2-1-R), the European Regional Development Fund (FEDER) and the Generalitat Valenciana (Project Prometeo 2012/064). H. Bourekoua acknowledges the financial support of Institute of Nutrition, Food and Agrofood Technology (I.N.A.T.A.A.).Peer reviewe

Optimization of Xanthan and Locust Bean Gum in a Gluten-Free Infant Biscuit Based on Rice-Chickpea Flour Using Response Surface Methodology

© 2020 by the authors.Incorporation of xanthan gum and locust bean gum in rice flour supplemented by chickpea flour was used to obtain a good quality of nutritionally enriched biscuit for celiac children. Response surface methodology (RSM) was applied to optimize the levels of xanthan and locust bean gum added to the composite gluten-free flour. Analysis was based on the rheological (hardness and viscoelastic) characteristics of the dough and specific volume, water activity, and hardness of the biscuit. The results revealed that the regression and variance analysis coefficients related to the rheological and physical properties of dough and biscuit under the influence of independent variables were sufficient for an adequate and well-fitted response surface model. Linear terms of variables significantly affect most of the dough and biscuit parameters, where the xanthan gum effect was found to be more pronounced than locust bean gum. Interaction terms showed a significant positive effect on the specific volume of the biscuits and a negative effect on the water activity. However, the interactive effect of gums did not significantly affect the rheological parameters of the dough. Optimized conditions were developed to maximize the specific volume of biscuit and minimize water activity and biscuit hardness, while keeping hardness and viscoelastic properties of the dough in range. Predicted responses were found satisfactory for both rheological and physical characteristics of dough and biscuit.This research was funded by the Ministère de l’Enseignement Supérieur et de la Recherche Scientifique. Université des frères MENTOURI- Constantine for finantial support to author S. Benkradi (Programme de formation residentielle à l’etranger (PNE)).Peer reviewe

Effect of hydrothermal treated corn flour addition on the quality of corn-field bean gluten-free pasta

Corn semolina supplemented by field bean semolina in ratio of 2/1 (w/w) were used for obtaining protein and fiber enriched gluten-free pasta. The effect of hydrothermal treatment of corn flour on its applicability as gluten-free pasta improver was tested. A central composite design involving water hydration level and the amount of hydrothermal treated corn flour were used. Instrumental analyses of pasta (cooking loss, water absorption capacity, hydration and pasting properties, textural parameters and microstructure) were carried out to assess the impact of experimental factors. Results showed that hydrothermal treatment of corn flour affected in different extent on pasta properties, improving cooking and textural characteristics of pasta. The optimum formulation of corn-field bean contained 7.41 g of treated corn flour and 77.26 mL of water was selected on the base of desirability function approach with value of 0.825 which showed the best pasta properties. Obtained results showed also that addition of treated flour induced significant differences (p < 0.05) in all parameters in comparison with control pasta

Effect of hydrothermal treated corn flour addition on the quality of corn-field bean gluten-free pasta

Corn semolina supplemented by field bean semolina in ratio of 2/1 (w/w) were used for obtaining protein and fiber enriched gluten-free pasta. The effect of hydrothermal treatment of corn flour on its applicability as gluten-free pasta improver was tested. A central composite design involving water hydration level and the amount of hydrothermal treated corn flour were used. Instrumental analyses of pasta (cooking loss, water absorption capacity, hydration and pasting properties, textural parameters and microstructure) were carried out to assess the impact of experimental factors. Results showed that hydrothermal treatment of corn flour affected in different extent on pasta properties, improving cooking and textural characteristics of pasta. The optimum formulation of corn-field bean contained 7.41 g of treated corn flour and 77.26 mL of water was selected on the base of desirability function approach with value of 0.825 which showed the best pasta properties. Obtained results showed also that addition of treated flour induced significant differences (p < 0.05) in all parameters in comparison with control pasta

Immobilization/Stabilization of Ficin Extract on Glutaraldehyde-Activated Agarose Beads. Variables That Control the Final Stability and Activity in Protein Hydrolyses

Ficin extract has been immobilized on different 4% aminated-agarose beads. Using just ion exchange, immobilization yield was poor and expressed activity did not surpass 10% of the offered enzyme, with no significant effects on enzyme stability. The treatment with glutaraldehyde of this ionically exchanged enzyme produced an almost full enzyme inactivation. Using aminated supports activated with glutaraldehyde, immobilization was optimal at pH 7 (at pH 5 immobilization yield was 80%, while at pH 9, the immobilized enzyme became inactivated). At pH 7, full immobilization was accomplished maintaining 40% activity versus a small synthetic substrate and 30% versus casein. Ficin stabilization upon immobilization could be observed but it depended on the inactivation pH and the substrate employed, suggesting the complexity of the mechanism of inactivation of the immobilized enzyme. The maximum enzyme loading on the support was determined to be around 70 mg/g. The loading has no significant effect on the enzyme stability or enzyme activity using the synthetic substrate but it had a significant effect on the activity using casein; the biocatalysts activity greatly decreased using more than 30 mg/g, suggesting that the near presence of other immobilized enzyme molecules may generate some steric hindrances for the casein hydrolysis

Chleb z pszenicy durum: schemat wytwarzania oraz charakterystyka jakości tradycyjnego algierskiego chleba Khobz Eddar

The purpose of this work was to evaluate the cellular structure and the physical and sensory properties of traditional Algerian bread named Khobz Eddar after establishing the flow diagram of its manufacturing by a household survey. The household survey involving 50 Algerian housewives was realised in the town of Constantine (Algeria). A majority of the women reported that Khobz Eddar bread is made using durum wheat semolina, salt, yeast, water, oil and eggs, and also nigella and sesame seeds on bread surface. Subsequently, Khobz Eddar bread was produced under controlled conditions, in a laboratory, according to the results of the household survey, and it was tested for its quality. The results showed that the traditional bread had a specific volume of 3.64 cm3 g–1, a low hardness and chewiness (13.15 and 3.70 N), and a high springiness of 0.867. Colour measurments showed crumb lightness with L* value of 72.66 and brown crust of bread with L* value of 57.78. Cellular analysis of bread crumb images indicated a number of cells of 628.5 per 778.63 mm2 total cell area with small holes (1.14 mm2). Produced bread was found acceptable and desirable with respect to its volume, colour, texture and crumb structure. Sensory analysis indicated also that Khobz Eddar is an apreciated bread.Celem pracy było określenie właściwości fizycznych, struktury komórkowej oraz cech sensorycznych tradycyjnego algierskiego chleba o nazwie Khobz Eddar. Oznaczenia te wykonano po ustaleniu schematu jego produkcji na podstawie badań ankietowych przeprowadzonych w gospodarstwach domowych. W mieście Constantine (Algieria) zrealizowano ankietę obejmującą opinie na podstawie doświadczeń 50 gospodyń domowych. Większość kobiet zgłosiła, że chleb Khobz Eddar jest wytwarzany przy użyciu semoliny z pszenicy durum, soli, drożdży, wody, oleju i jaj, posypkę stanowią nasiona czarnuszki i sezamu. Opracowany schemat produkcji wykorzystano do wypieku chleba Khobz Eddar w kontrolowanych warunkach w laboratorium. Wyniki oceny jakości uzyskanego chleba wykazały, że miał on objętość na poziomie 3,64 cm3·g–1, miękisz charakteryzował się niską twardością i żuwalnością (13,15 i 3,70 N) oraz dużą sprężystością 0,867. Pomiary barwy wykazały jasną barwę miękiszu o wartości L* wynoszącej 72,66, natomiast skórka chleba miała barwę brązową, dla której L* wynosiła 57,78. Analiza obrazu w tym ocena porowatości miękiszu wykazała liczbę komórek 628,5 mieszczącą się na powierzchni 778,63 mm2 z małymi porami (1,14 mm2). Wyprodukowany chleb biorąc pod uwagę jego objętość, kolor oraz strukturę miękiszu uznano za akceptowalny i pożądany. Analiza sensoryczna wysoce doceniła walory trakcyjnego chleba Khobz Eddar

How microwave treatment of gluten affects its toxicity for celiac patients? A study on the effect of microwaves on the structure, conformation, functionality and immunogenicity of gluten

International audienc