Rye Flour Research Articles

Understanding the impact of water-extractable cereal flour constituents on network formation in gluten-starch dough

Water-extractable cereal flour constituents influence bread loaf specific volume, suggesting a contribution to gas cell (de)stabilization in dough. However, the underlying mechanism remains largely unexplored. We studied the impact of incorporating five cereal flour aqueous extracts in model gluten-starch bread (doughs) on specific volume, dough extensional rheology, and protein extractability changes during bread making. Incorporating wheat, rye, or triticale flour aqueous extracts in gluten-starch doughs increased bread specific volume by 12–17%. There were no changes in dough rheology that could explain this specific volume increase, suggesting that other mechanisms relating to gas cell stabilization might be at play. Incorporating oat flour aqueous extracts decreased bread specific volume by 50%. This negative impact was related to poor dough strain hardening behavior, in turn probably explained by disruption of intermolecular glutenin disulfide bonds, as revealed by chromatography. While this study has provided a novel perspective on the mechanisms by which water-extractable cereal flour constituents influence bread volume, it also demonstrates that the compositional heterogeneity of the flour aqueous extracts needs to be addressed to allow an even better understanding of the role of water-extractable cereal flour constituents in stabilizing gas cells in bread dough.

Development of Functional Bread Technology Based on a Baking Mixture of Bioactivated Wheat and Rye

Introduction: In connection with the acquisition of new data in the field of metabolic aspects of food pharmacology and toxicology, the production volume of functional products is growing every year and is one of the important priority directions for the development of the food industry. To enrich bakery products, bioactivated grain, flour from whole wheat and rye, and bakery mixes using these types of flour have been widely used lately. The preparation of grain bread based on a bakery mix made from wheat and rye bioactivated by the disintegration-wave method leads to products with a sticky, highly kneadable crumb.Purpose: To develop a bakery mix using flour from whole grain bioactivated wheat and rye and a technology for functional bread of improved quality based on it.Materials and Methods: The objects of research were ten samples from baking mixes with different compounding components. In the fermentation test, the fermentation activity was determined on the National rhizograph, the acidity was determined by titration. The quality of bread after 20 hours of storage and its chemical composition were evaluated in accordance with generally accepted methods specified in current standards.Results: The best dough properties and bread quality were observed in the sample made based on the bakery mix without the use of dry wheat gluten, with an increased dosage of ascorbic and citric acids, whey, in which 100 grams contained equal parts of flour from whole grain bioactivated rye and wheat, peeled rye flour, and first-grade wheat flour (each at 23.63%). As a result of evaluating the chemical composition of the developed product, it was found that it is classified as a functional food due to its significant content of magnesium, phosphorus, iron, thiamine, and riboflavin.Conclusion: The choice of a bakery mix composition using flour from whole grain bioactivated rye and wheat has been justified to produce functional bread with a nearly non-kneadable crumb. A preparation technology has been developed, which will intensify the technological cycle of product production by eliminating the dough fermentation stage.

Research on the Rheological Properties of Dough Based on Dry Flour Semi-Finished Products Using Rye Flour

The market formation of functional bakery products enriched with valuable non-traditional raw materials meets the principles of healthy nutrition and satisfies individual human needs. Dry flour semi-finished products are heterogeneous systems consisting of several components, which requires an analysis of its technological combination and mutual influence. The study aims at quality assessment of dry flour semi-finished products of various formulations using rye flour according to the “Simulator” protocol and through the “Profiler” system in automated mode on the “Mixolab Chopin” device. The water absorption capacity of the prototypes had a range of values from 52.0 to 59.7%, in the control – 57.3%. The researchers revealed rheological characteristics features of the dough obtained on the basis of different dry flour semi-finished product types due to the impact of protein-proteinase and carbohydrate-amylase complexes of individual components. The production of dough based on most of the considered dry flour semi-finished products requires less water than traditional dough based on wheat flour. The presented dry flour semi-finished products are mainly capable of forming a “stable” dough with good elasticity. The thesis presents mixolabograms together with the Mixolab Profiler function of a test sample based on a dry flour semi-finished product “Plain Rye Bread”. “Mixolab Chopin” is applicable to study the properties and quality control of dry flour semi-finished products using rye flour, additional and non-traditional raw materials. The shelf life of products based on the considered dry flour semi-finished products are at the level of shelf life of products based on wheat flour grade I.

Mixed Psyllium Fiber Improves the Quality, Nutritional Value, Polyphenols and Antioxidant Activity of Rye Bread.

The aim of the study was to determine the influence of the different shares (0/100, 5/95, 10/90 and 15/85 ratios) of a ground psyllium fiber (PF) mixture of 80% psyllium seeds (Plantago psyllium) and 20% psyllium husk (Plantago ovata Forsk) on the quality characteristics, chemical composition, total polyphenolic content (TPC), and antioxidant activity of rye bread (RB). The study was conducted with rye flour (RF) type 580 and 720 and two dough preparation methods (single-phase-1F, two-phase-2F). The inclusion of psyllium fiber in rye bread resulted in an increase in the overbaking of bread by 12.4%, total protein by 1.7%, ash by almost twofold, and TDF content by more than twofold. Psyllium fiber addition also led to a twofold improvement in antioxidant activity and an increase in TPC from 35.5 to 109.1 mg GAE/100 g d.m., as well as enhanced porosity of the crumb from 7.1 to 7.6 points on the Mohs scale. However, it caused a decrease in specific loaf volume by 10%, springiness by 3.5%, chewiness by almost 12%, and gumminess of the crumb by 8.1%. A darkening of the crust (reduction in the L* value by 10.7%) and crumb (reduction in the L* value by 37.6%) was observed as well. Notably, the results indicated that a 10% share of PF can be considered a potentially beneficial and functional ingredient, promoting health benefits without negatively affecting the physical and sensory qualities of rye bread. This suggests the potential use of PF for enhancing the nutritional value of RB without compromising its overall quality.

Occurrence of Types A and B Trichothecenes in Cereal Products Sold in Romanian Markets.

In view of the frequent occurrences of mycotoxins in cereals, this study assessed the presence of trichothecenes in 121 samples from Romanian markets. These samples were divided into five groups based on product type: (1) bread and bakery products containing white flour, (2) half-brown bread with whole wheat flour, (3) brown bread containing rye flour, (4) pasta, and (5) raw wheat. Gas Chromatography-Mass Spectrometry was used to detect 13 different mycotoxins, which included the Type A compounds HT-2 toxin and T-2 toxin, as well as the Type B compounds deoxynivalenol and nivalenol. Results indicated trichothecene contamination in 90.08% of our samples, with deoxynivalenol predominating by at least 78% in each examined group. Co-occurrence of three or four trichothecenes were found in 23.85% of our samples. Our study underscores the necessity of consistent monitoring of staple foods to prevent the intake of harmful trichothecenes by consumers.

Detection of adulteration in Eragrostis tef (Zucc.) Trotter flour using EDXRF and ComDim-MLR data fusion

The teff cereal gained worldwide attention because it is gluten-free and rich in iron; thus, its flour is subject to fraud. This study evaluated the ability of Energy Dispersive X-Ray Fluorescence Spectroscopy (EDXRF) to identify teff flours adulterated with rice, whole wheat, oat, and rye flours. The adulteration followed a {5,4} simplex-lattice design. After smoothing and pretreatments, 15 kV and 50 kV spectra were fused by Common Dimension Analysis (ComDim). Multiple Linear Regression (MLR) models using EDXRF-ComDim scores and percentage of teff were adjusted. The best model presented four common dimensions (CD), r2prediction = 0.8534, low RMSEP (0.0564), and absence of overfitting. The obtained model was robust to quantify adulteration in teff flour even with the differences in the intensity of EDXRF spectra of different crops. Therefore, EDXRF, in tandem with ComDim data fusion, was an efficient tool for the adulteration control of teff flours.

Validation of the GlutenTox® ELISA Rapid G12 Test Kit for Determination of Gluten in Select Non-Heat Processed Matrixes and Heat Processed Matrixes.

The GlutenTox® ELISA Rapid G12 test kit is a quantitative method designed for the determination of the immunotoxic fraction of gluten in food samples. To obtain AOAC PTM certification for the method for the detection and quantification of gluten from wheat, barley and rye flours in select foods (non-heat processed) and incurred (heat processed) matrixes. The method was evaluated following the "Validation Procedures for Quantitative Gluten ELISA Methods: AOAC Allergen Community Guidance and Best Practices" (1). The validation study was conducted at Hygiena Diagnóstica España using 5 food matrixes (soy flour, corn bread, seasoning mix, rolled oats and evaporated milk) artificially contaminated with gluten from wheat, barley or rye flour at different concentrations: 0, 5, 10, and 20 mg/kg. For each matrix and gluten contamination level, 5 or 6 individually extracted test portions were analyzed. A second bread matrix was prepared by baking a gluten free bread mix spiked at 0, 20 and 30 mg/kg gluten from wheat, barley or rye flour for incurred matrix testing. Ten individually extracted test portions were tested for each incurred bread and contamination level of gluten. The method met the AOAC performance requirements (2) for detection and quantification of wheat gluten in the selected food matrixes, incurred bread sample and spike levels of wheat gluten, showing an acceptable recovery. When tested with barley and rye flours, most of the results showed acceptable recoveries or a slight overestimation, depending on the matrix and gluten concentration. Method developer and independent laboratory results were comparable. The validation study demonstrated the test kit is a reliable, accurate, quick and easy to use method for the detection and quantification of gluten concentration in food and incurred matrixes from wheat, barley and rye flours. Most reagents provided in the kit are at ready-to-use concentrations.

Influence of the use of chestnut starch as a binder filler in plywood technology

: Influence of the use of chestnut starch as a binder filler in plywood technology. Fillers play a crucial role in the production of plywood glues, providing enhanced performance and stability to the end product. Plywood, being a composite material, requires fillers to improve its mechanical properties, adhesion, and overall quality. One common filler used in plywood glues is calcium carbonate. It acts as a bulking agent, increasing the volume and density of the adhesive mixture while reducing production costs. Calcium carbonate also enhances the glue's viscosity, ensuring proper bonding and uniform application during the plywood manufacturing process. Another widely used filler is rye or wheat flour, which consists of finely ground grains. The flour not only improves the adhesive's viscosity but also contributes to the overall strength and stability of the plywood. It helps to prevent warping and enhances dimensional stability, making the final product more durable. Additionally, other fillers like talc or clay minerals may be incorporated into the glues to improve their adhesive properties and increase moisture resistance. Chestnut starch is a type of vegetable flour made by grinding edible chestnuts into a powder. It has a different texture and properties than traditional wheat or rye flour. When used as a binder filler in plywood technology, it can be biodegradable and environment-friendly. In the study, there were produced five types of plywood with 0, 1, 5, 10, and 20 parts by weight chestnut flour and one reference. All samples were produced in laboratory conditions and the selected mechanical and physical properties of the produced boards were studied. The mechanical properties of the boards increased with the addition of chestnut flour. In some tests, the results even met the highest requirements of European standards for plywood. According to this finding, a well-chosen addition of chestnut flour could be positively considered in plywood production.

Formation of the quality and shelf life of bread through the addition of rowanberry powder

The object of the study is bread made from medium rye flour enriched with rowan powder. The study is devoted to the formation of quality and increase of the shelf life of bread. The technology of obtaining powder from Sorbus aucuparia involves freezing fruits, preliminary dehydration by osmotic dehydration, drying and grinding. It was found that rowan powder contains the highest amount of potassium (860 mg/100 g) and 6.7 % crude fiber. Rowan powder contains 1.72 mg/100 g of vitamin C, which gives it antioxidant properties. The experimental samples of bread from medium rye flour were made by the liquid sponge method. Rowan powder was added to samples D1, D2, and D3 in an amount of 5, 10, and 15 %, respectively. The control sample (C) was made according to a standard recipe. The analysis of the physicochemical parameters of bread quality showed that with an increase in the amount of rowan powder added, the acidity of the samples increased, but did not exceed the standard values. Rowan powder did not significantly affect the moisture content of the bread crumb. With the addition of 5 and 15 % powders, the moisture content was 46.7 and 46.6 %, respectively. In sample D2, which contained 10 % rowan powder, the moisture content was the lowest – 45.9 %. The effect of rowan powders on the storage ability of rye flour bread was investigated. It was found that mold appeared on the surface of sample C on the 5th day of storage. In the sample with a rowan powder content of 5 % – on the 12th day of storage, with a powder content of 10 % – on the 21st day of storage. On sample D3, mold was observed on the 16th day of storage. These results indicate that rowan powder can be used as a natural preservative that can significantly increase the shelf life of rye flour bread

Технологические свойства теста из смеси ржаной и пшеничной муки с продуктами переработки облепихи

Processed fruit and berry raw materials often become part of bakery formulations. They increase the nutritional value of the finished product and change the rheological properties of the dough. Processed sea buckthorn (Hippophaё rhamnoides L.) maintains natural biochemical properties, which makes it a valuable food ingredient. The research objective was to conduct a comprehensive study of the technological properties of dough made of rye and wheat flour with sea buckthorn meal and dry sea buckthorn extract.
 The research involved sea buckthorn extract and meal mixed with wheat and rye flour, as well as dough and bread from the experimental flour mixes. The experimental part included standard methods used in the bakery industry.
 The sea buckthorn meal and extract contained protein (10.3 and 4.3%), crude fiber (8.7 and 0.3%), pectin (5.27 and 0.11%), and ascorbic acid (21.63 and 53.68 mg/100 g). They were highly acidic: 4.9 and 3.0%, respectively. As a result, protein substances and dietary fibers took a longer time to swell. The high acidity also inhibited α-amylase, which improved the rheological properties but increased the dough development time and stability. The sea buckthorn products had a positive effect on the starch crystallization processes and reduced the storage-related starch degradation. The sensory evaluation of the bread described its shape as regular, with fluffy crumb and pleasant sea buckthorn flavor. 
 Thus, sea buckthorn meal and extract proved excellent technological acidifiers and regulators of amylolytic activity. The additives made it possible to reduce the amount of liquid rye sourdough from 30 to 15% and the fermentation time because the dough acidity reached 7.5–8.0 degrees.

Screening of different flours for 3D food printing: Optimization of thermomechanical process of soy and rye flour dough

3D food printing allows the development of personalized food, but it is necessary to diversify the printable recipes to propose a varied food offer. The objective of this project was to explore the printability potential of different flours and to optimize a thermomechanical process (mixing and heating of water and flour) to ensure good print quality. A bibliographic study of 25 flours and an experimental screening of five flours was conducted. Thanks to the previous steps, soy and rye flour were selected because of their interesting nutritional value and their printability potential. An experimental design (10 trials) for each flour showed a significant impact of the process parameters studied (percentage of water content and duration of the thermomechanical treatment) on print quality. The reverse engineering approach demonstrated that the optimal water content is similar for both flour (Soy: 59%, Rye: 60%), but the optimal duration of the thermomechanical treatment is quite different (Soy: 27 min, Rye: 22 min). Industrial relevance textInterest in 3D food printing has continued to grow in recent years. Products with different flavors, shapes and textures have been proposed in many studies. However, print quality is not always easy to predict and to obtain, especially when faced with nutritional or functional constraints. In our study, we developed a 3-steps approach (two screening steps including bibliographic and experimental method and then one optimization step) to propose new edible ink combining interesting nutritional composition and good print quality. To achieve this goal a design of experiments based on two process parameters (water content and duration of thermomechanical treatment) was conducted and a predictive model was established for soy and rye flours. The reverse-engineering method allowed determining the process parameters to use to ensure good print quality and stability of 3D-printed products. This approach could be applied for the development of new edible ink using other flours or integrating different ingredients.

Use of lentil flour in special purpose bread

Purpose. To study the peculiarities of the indicators of quality formation of bread made with the addition of lentil flour. Methods. The research was carried out according to the technology of bakery and pasta production. Products made from wheat flour of the first grade and rye were used as a control, while the bread made with the addition of 5 to 30% of lentil flour (variety 'Chrysolit'. The bread was baked in a cabinet oven at a temperature of 220 ± 2°C. Both ready dough and end product was evaluated by physico-chemical and organoleptic indicators. Results. The addition of lentil flour had different effects on the quality of wheat and rye bread. In particular, in wheat flour dough, with the addition of 5–30% lentil flour, the final acidity increased from 2.5 to 2.7–3.8 degrees, or 1.1–1.5 times. The release of carbon dioxide decreased from 848 to 646–790 cm3/100 g, or 1.1–1.3 times. The water content of the dough changed insignificantly. The duration of maturation decreased from 63 to 41–57 min, porosity from 78 to 52–74%. Baking increased from 4.3 to 4.7–8.5%, drying – from 4.5 to 5.0–7.0%. In the rye flour dough, the acidity decreased from 2.8 degrees in the control to 1.5–2.3 degrees, or 1.2–1.9 times with the addition of 5–30% lentil flour. The water content of the dough was at the control level, as it did not change significantly. With the addition of 5–10% lentil flour, the duration of fermentation decreased from 60 to 50–55 min, and with the addition of 15–30% lentil flour, it increased to 62–67 min. With the addition of 5–30% lentil flour, dimensional stability decreased from 0.50 to 0.25–0.48, porosity – from 72 to 42–67%. Baking of rye bread increased from 5.5% in the control to 5.8–9.4%, and drying increased from 6.0 to 6.6–8.8%, depending on the variant of the experiment. It should be noted that the addition of 5–15% lentil flour did not change the appearance of wheat and rye bread. The addition of 20–30% lentil flour ensured the formation of bread that did not meet the standards of DSTU 7517:2014. Wheat Flour Bread. General Technical Conditions and DSTU 4583:2006. Rye Bread and a Mixture of Rye and Wheat flour. General technical conditions. Conclusions. Adding 5–15% lentil flour to a wheat or rye bread recipe does not change the appearance of the bread. The surface of the bread was smooth without cracks and dents, the color of the crust was light green, and the color of the crumb was light, with barely noticeable specks of lentil flour. At the same time, the acidity increases and the release of carbon dioxide from the dough decreases. In addition, the addition of 5–15% lentil flour increases the baking and drying of wheat and rye bread, and the duration of maturation, dimensional stability, specific volume and porosity decrease. Adding 20–30% of lentil flour to the bread recipe is impractical, as it greatly spoils its appearance.

The cultivation of rye in marginal Alpine environments: a comparison of the agronomic, technological, health and sanitary traits of local landraces and commercial cultivars.

Rye is a secondary crop that is characterized by a higher tolerance to climatically less favorable conditions than other cereal species. For this reason, rye was historically used as a fundamental raw material for bread production and as a supply of straw in northern parts of Europe as well as in mountain environments, such as Alpine valleys, where locally adapted landraces have continued to be cultivated over the years. In this study, rye landraces collected in different valleys in the Northwest Italian Alps have been selected as the most genetically isolated within their geographical contexts and cultivated in two different marginal Alpine environments. The traits concerning their agronomy, mycotoxin contamination, bioactive content, as well as their technological and baking quality were assessed to characterize and compare rye landraces with commercial wheat and rye cultivars. Rye cultivars showed the same grain yield level as wheat in both environments. Only the genotype selected from the Maira Valley was characterized by tall and thin culms and a proneness to lodging, thereby resulting in a lower yield capacity. Among the rye cultivars, the hybrid one presented the highest yield potential, but also the highest susceptibility to the occurrence of ergot sclerotia. However, the rye cultivars, especially the landraces, were characterized by higher concentrations of minerals, soluble fibers, and soluble phenolic acids, and thus both their flours and breads had superior antioxidant properties. A 40% substitution of refined wheat flour with whole-grain rye flour led to a higher dough water absorption and a lower stability, thereby resulting in lower loaf volumes and darker products. Agronomically and qualitatively speaking, the rye landraces diverged significantly from the conventional rye cultivars, thus reflecting their genetic distinctiveness. The landrace from the Maira Valley shared a high content in phenolic acids and good antioxidant properties with the one from the Susa Valley and, when combined with wheat flour, turned out to be the most suitable for bread making. Overall, the results have highlighted the suitability of reintroducing historic rye supply chains, based on the cultivation of local landraces in marginal environments and the production of value-added bakery goods.

Relevance of increasing the share of winter rye in production crops of Western Siberia

Winter rye, which has many valuable properties, is a very important crop in the grain area. The analysis of long-term data on the size of sown areas of winter rye in Russia shows their rapid decline. In this regard, the example of the “Rye” program, implemented by the Finnish government to promote and increase the consumption of rye flour products, as well as the experience of establishing an information center engaged in educational activities among the population is presented. The state of the State Register of Breeding Achievements Approved for Use in winter rye was considered: it was revealed that domestic breeding varieties accounted for 87.1%, foreign - 12.9%. At the same time, 18 varieties exclusively of domestic breeding were recommended for cultivation in Western Siberia, including four varieties of tetraploid rye. Over the past decade, five varieties of winter rye have been registered in the region. The ratio of the size of sown areas under the crop in the Russian Federation as a whole, the Altai Territory and the Novosibirsk Region is presented. The data for the Novosibirsk region for 2019-2021 on the yield of major winter crops, the volume of sowing of winter rye varieties and the hybrids included in the State Register were analyzed. The situation in the production of winter rye and its products, as well as the prospects for the use of this crop in crop rotations in Western Siberia were studied. Indicators of maximum yield of winter rye varieties and hybrids are given, their advantages and disadvantages are listed. The importance of creating a collection of varieties and hybrids in the region and the need to increase the production of winter rye and its products are justified.

Physicochemical and microbiological properties of Arabic flatbread produced from wild natural sour starters

Background and objectivesExtensive research studies worldwide have discussed and analyzed the sourdough nutritional, chemical, and biotechnological aspects of western types of bread. However, the literature on sourdough usage in Arabic bread processing is very limited. The present study aimed to come up with a new fermentation technique at the bakery level. The new technique is hoped to reveal the traditional nostalgic characteristic flavor of Arabic bread produced using natural sourdough instead of the traditional yeasted dough and study its effect on the resulting bread. Three types of flour (straight grade, whole wheat, and rye) that are ordinarily used in Jordan were used to prepare three natural sour starters using the backslopping technique. FindingsDominant yeast species isolated from the traditional sour starter of the local Jordanian whole wheat were Saccharomyces cerevisiae, Candida glabrata, and Zygosaccharomyces spp., while rye and straight-grade starters showed different domination patterns. The dominant species of lactic acid bacteria (LAB) isolated from the traditional sour starter of the local Jordanian whole wheat (Horani cultivar) were Lactiplantibacillus plantarum2, Lactobacillus delbrueckii ssp bulgaricus, and the Lacticaseibacillus paracasei ssp paracasei3, while mixed strains of LAB isolates were obtained for the rye and straight-grade flour starters on day 7 of preparation.The pH results showed no significant differences (P > 0.05) between the three types of sour starters, while the total titratable acidity (TTA) results showed a significant increase (P ≤ 0.05) in whole wheat sour starters with a TTA value of 11.17 ± 0.11 ml 0.1 N NaOH/10g dough. The 20% and 30% straight-grade sour bread samples and the control exhibited the highest scores in terms of acceptability and total quality scores. ConclusionsThe incorporation of sourdough in Arabic flatbread processing showed remarkable results in extending the shelf life by using natural ingredients, improving the quality, and providing tastier and more convenient bread.

Investigation of the effects of sample preparation on gluten quantitation in rye and barley flours

AbstractProper gluten quantitation is essential for providing safe gluten-free food for patients living with celiac disease (CD). However, gluten quantitation faces several challenges: the lack of a reference method and certified reference materials, the variability of methods and the effects of genetic and environmental factors on gluten. Among all these challenges our research group focuses on gluten reference material development. Gluten content is determined by enzyme linked immunosorbent assay (ELISA) methods to obtain comparable data for the selection of cultivars used in our reference material development efforts. As ELISA methods are developed for determining low gluten concentrations, application for these special research purposes requires a 10,000-fold dilution. The formerly performed process was a post-extraction liquid dilution that proved to be sufficient for wheat samples. However, gluten contents of rye and barley samples were found to be overestimated by ELISA methods. One of the suggested reasons is the structural and solubility changes of gluten proteins during the dilution process. Therefore, our present study focuses on the comparison of the original dilution method and a revised version using solid-phase dilution in a gluten-free matrix.

Dietary Exposure to Toxic Metals (Cd, Pb and Hg) from Cereals Marketed in Madeira and the Azores.

Cereals and cereal-based foods continue to be basic foods in all diets. Despite being known for their high nutritional value; they can also contain contaminants (hazards) such as toxic metals. This study assesses the Cd, Pb and Hg dietary exposure from cereals and derivatives marketed in Madeira and the Azores and characterizes the risks by evaluating the Cd and Hg intake contributions to the tolerable intakes and by estimating the Margin of Exposure (MOE) in the case of Pb. In Madeira, metals follow the descending order of Cd > Pb > Hg. Cd stands out as having the highest levels (0.307mg Cd/kg in oats; 0.237mg/kg in rye). High levels of Pb (0.347mg/kg) were also detected in rye. Regarding total mercury, rice stands out (0.0013mg/kg) followed by wheat (0.001mg/kg). While all cereals and derivatives except maize consumed in Madeira exceed the maximum value of Cd allowed by the EU, 50.0% of the rye and 25.0% of the corn flour samples exceeded the European Pb limit. The daily consumption of 100g of oats, rye flour and rye represent high contributions to the TWI of Cd (93.2 - 120%). The MOE values of Pb from the consumption of rye (100g/day) are 1,294 (nephrotoxic effects) and 3,082 (cardiotoxic effects).In the Azores, corn flour (0.72mg Pb/kg) stands out with 85.7% of the samples exceeding the maximum Pb EU limit and MOE values of 626 (nephrotoxic effects) and 1,490 (cardiotoxic effects). Regular daily consumption of corn flour makes a low (< 10%) contribution to the Cd TDI.In conclusion, the Pb exposure from the consumption of cereals and derivatives could have toxic effects such as nephrotoxicity or cardiotoxicity in adults. The results highlight the need to set up monitoring and surveillance programs for the safety of cereals and their derivatives in Madeira and the Azores in terms of lead and cadmium.

Effects of Chromium, Cadmium and Lead on the Growth and Survival of Rats

Eight groups of more than 50 hooded rats were each given (at 5 ppm) cadmium, trivalent chromium or lead in drinking water while fed a diet of rye flour, dried skim milk and corn oil containing no detectable cadmium and only small amounts of chromium and lead. Extensive precautions were taken to avoid environmental metallic contamination. The diet was nutritionally adequate for survival, all but 7 control animals surviving 21 months. Mortality of rats receiving chromium was equally low. Although those given lead and cadmium grew normally, survival was considerably reduced when their tissue concentrations of metal were approximately similar to or less than those of adult human beings. No metallic toxicity appeared. Growth of males was stimulated by chromium and mature animals were larger than the controls. Cadmium was not detected in the livers and kidneys of animals not given it, although they grew normally and survived. Cadmium is not an “essential” trace metal for rats in terms of growth and survival; it shortens their lives at less than human renal concentrations. Lead at human tissue concentrations has a similar innate toxicity in terms of survival. If chromium has a metabolic function, these experiments confine it to male rats.

Hierarchical Effects of Lactic Fermentation and Grain Germination on the Microbial and Metabolomic Profile of Rye Doughs.

A multi-omics approach was adopted to investigate the impact of lactic acid fermentation and seed germination on the composition and physicochemical properties of rye doughs. Doughs were prepared with either native or germinated rye flour and fermented with Saccharomyces cerevisiae, combined or not with a sourdough starter including Limosilactobacillus fermentum, Weissella confusa and Weissella cibaria. LAB fermentation significantly increased total titrable acidity and dough rise regardless of the flour used. Targeted metagenomics revealed a strong impact of germination on the bacterial community profile of sprouted rye flour. Doughs made with germinated rye displayed higher levels of Latilactobacillus curvatus, while native rye doughs were associated with higher proportions of Lactoplantibacillus plantarum. The oligosaccharide profile of rye doughs indicated a lower carbohydrate content in native doughs as compared to the sprouted counterparts. Mixed fermentation promoted a consistent decrease in both monosaccharides and low-polymerization degree (PD)-oligosaccharides, but not in high-PD carbohydrates. Untargeted metabolomic analysis showed that native and germinated rye doughs differed in the relative abundance of phenolic compounds, terpenoids, and phospholipids. Sourdough fermentation promoted the accumulation of terpenoids, phenolic compounds and proteinogenic and non-proteinogenic amino acids. Present findings offer an integrated perspective on rye dough as a multi-constituent system and on cereal-sourced bioactive compounds potentially affecting the functional properties of derived food products.

Insight in changes in starch and proteins molecular structure of non-wheat cereal flours influenced by roasting and extrusion treatments

Barley, rye, triticale, oat, sorghum and millet flours, subjected to roasting or extrusion treatment, were analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) and Raman spectroscopy with aim to determine structural changes within starch and protein molecules that caused specific rheological properties of heat treated flours. Mixolab was used to determine how changes in starch and protein structure are reflected in rheological properties of dough. Extrusion treatment caused more extensive changes both in starch and protein structure than roasting treatment. Changes of protein secondary structure from α-helix to β-turn aggregated by hydrogen bonds, formed mainly between tyrosyl groups, as well as change in disulphide bond conformation, were more pronounced in extruded flour samples. Changes in the starch structure were also more extensive in extruded flours samples, including complete gelatinization and formation of amylose-lipid complexes. The results obtained by Mixolab showed that all extruded doughs showed resistance at C2 point, which was shifted to approximately 30 min, indicating higher mechanical resistance. It was supposed that this change in dough behaviour is related to protein polymerization during extrusion treatment and starch aggregation during roasting treatment.