Stone Milling versus Roller Milling in Soft Wheat (Part 2): Influence on Nutritional and Technological Quality of Products.

Wholegrain soft wheat flours can be obtained by either roller milling or stone milling. In this paper, we report on the continuation of a study aimed at analysing compositional and technological differences between differently milled wholegrain flours. Eight mixes of soft wheat grains were stone milled and roller milled and the milling products analysed for their phytic acid, lipids composition to determine the presence of trans-fatty acids and damaged starch. A wholegrain flour milled with a laboratory disk mill was also analysed as comparison, as well as seven wholegrain flours purchased on the market. For phytic acid we found that that there is no compositional difference between a stone milled or a roller milled flour if the milling streams are all recombined: the milling streams instead have different amounts of phytic acid which is mainly present in the fine bran and coarse bran. It was not possible to highlight differences in the milling technology due to the presence of trans-fatty acids in the stone milled wholegrain flour whereas it was possible to find that starch damage depended on the milling method with stone milled wholegrain flours having in all cases significantly higher values than the roller milled ones.

Quality and Nutritional/Textural Properties of Durum Wheat Pasta Enriched with Cricket Powder.

Edible insects have always been consumed by humans and nowadays they are looked at with interest by the research community as a means to produce food at low environmental cost for a growing and increasingly demanding population. A large number of different species are edible, and they can contribute fats, protein, fibre, vitamins, and minerals to the human diet. The absence of specific legislation on the use of insects as food, coupled with the general population's disgust at the idea of eating insects, are among the limiting factors for the development of insect farming in developed countries. Several consumer studies have concluded that hiding insects in traditional foods can increase people's willingness to eat insect-based foods. Cereal-based foods such as bread, bakery products, pasta, etc., being so popular worldwide and so widely accepted by the population, have been used by researchers as a carrier for the introduction of different percentages of insect flours to improve their nutritional qualities. The research by Duda et al. on "Quality and Nutritional/Textural Properties of Durum Wheat Pasta enriched with Cricket Powder" is the first recent scientific contribution to the understanding of the nutritional quality and technological effects of the introduction of insect flour in a popular food such as durum wheat pasta.

Nutritional Value of Grain-Based Foods.

Grains are fundamental in the daily diets of many people worldwide; they are used for the production of popular foods, such as bread, bakery products, breakfast cereals, pasta, couscous, bulgur, and snacks. Botanically, they are the seeds of plants, belonging mainly to the groups of cereals, pseudocereals, and legumes. They contribute macronutrients to the human diet, mainly carbohydrates, but also proteins and lipids, and micronutrients, such as vitamins and minerals. They are also an important source of dietary fibre and bioactives, particularly wholegrains, which are of interest for the manufacturing of high value foods with enhanced health benefits. They can be used for the production of gluten-containing (as well as gluten-free) products. One of the main objectives of the food industry when producing grain-based foods is to manufacture safe, attractive products, with enhanced nutritional value to respond to consumer expectations. The following Special Issue "Nutritional Value of Grain Based Foods" consists of one review and eight original research papers that contribute to the existing knowledge of important ingredients, such as fat substitutes, and of the technological quality and nutritional role of grains and grain-based foods (gluten-containing and gluten-free), such as bread, muffins, and muesli bars.

A Comprehensive Study on the Influence of Sodium Chloride on the Technological Quality Parameters of Soft Wheat Dough.

This study aimed at understanding how the presence or absence of NaCl influences dough rheological performance of soft wheat cvs. currently used in the Italian bread manufacturing industry as a scientific support to national health strategies to reduce the use of NaCl in bread. For this reason 176 flour samples belonging to 41 soft wheat cvs. currently cultivated in Italy, were analyzed for their protein content, Zeleny sedimentation value, and by means of the Chopin Alveograph and Brabender Farinograph, with no salt and with 1.5% salt addition (average salt content in Italian bread). Three selected cvs. (Aubusson, Bolero, and Blasco) were additionally studied by means of the Rapid Visco Analyzer (RVA) at three levels of salt addition (0%, 1.5% and 3.0%). The fermentation behaviour of the cvs. Aubusson and Blasco was also studied by means of a Rheofermentometer under the same conditions. The results of our study confirmed the role of salt in strengthening the wheat gluten network (up to 86%), and thus the gas retention of dough and in affecting yeast activity. However, it also definitely proved that careful cultivar selection can help in overcoming technical challenges in reduced-salt bread manufacturing and eventually, it opens the path to wheat breeding for reduced-salt bread baking.

Lipids and Fatty Acids in Italian Durum Wheat (Triticum durum Desf.) Cultivars.

The level of variation in lipids and their fatty acids was determined in the grains of 10 popular durum wheat cultivars commercially grown in Central and Southern Italy. Samples were harvested for two consecutive years to account for differences due to changes in climatic conditions. Total fat content was determined by means of the International Association of Cereal Science and Technology (ICC) Standard Method No. 136, whereas the fatty acid profile was determined by gas chromatography. Total lipid content ranged from 2.97% to 3.54% dry basis (d.b.) in the year 2010 and from 3.10% to 3.50% d.b. in the year 2011, and the average value was 3.22% d.b. considering both years together. Six main fatty acids were detected in all samples in order of decreasing amounts: linoleic (C18:2) > palmitic (C16:0) ≈ oleic (C18:1) > linolenic (C18:3) > stearic (C18:0) > palmitoleic (C16:1). Significant variations in the levels of single acids between two years were observed for three samples. These results will be very useful in the updating of food composition databases in general and will help authorities to set proper quality standards for wholegrain flours and products where the germ should be preserved, considering also the recent interest of industry and consumers for these kinds of products.

Stone Milling versus Roller Milling in Soft Wheat: Influence on Products Composition.

Wholegrain wheat flours are in great demand from consumers worldwide because they are considered healthier then refined flours. They can be obtained by either stone milling, which is experiencing a revival in Europe, or roller milling. In order to study compositional differences due to the milling technology and to explore the possibility of a better qualification of wholegrain flours by means of nutritionally oriented quality parameters, eight mixes of soft wheat grains were stone milled and roller milled and the milling products were analyzed for their protein, ash, lipids, total dietary fibre, total polyphenols and alkylresorcinols content. A wholegrain flour milled with a laboratory disk mill was used as a comparison and a set of seven wholegrain flours purchased on themarket were also analyzed and compared. The particle size distribution of stone milled and recombined roller milled flour was also studied. Considering the above mentioned parameters, we found that there is no compositional difference between a stone milled or a roller milled flour if, in this latter one, the milling streams are all recombined, but the particle size distribution was different. This might have an impact on the technological quality of flours and on the bioavailability of components.

Bread for the Aging Population: The Effect of a Functional Wheat-Lentil Bread on the Immune Function of Aged Mice.

A functional bread tailored for the needs of the aging population was baked by substituting 24% of wheat flour with red lentil flour and compared with wheat bread. Its nutritional profile was assessed by analysing proteins, amino acids, lipids, soluble and insoluble dietary fibre, resistant starch, total polyphenols, lignans and the antioxidant capacity (FRAP assay). The wheat-lentil bread had 30% more proteins than wheat bread (8.3%, as is), a more balanced amino acids composition, an almost double mineral (0.63%, as is) as well as total dietary fibre content (4.6%, as is), double the amount of polyphenols (939.1 mg GAE/100g on dry matter, d.m.), higher amounts and variety of lignans, and more than double the antioxidant capacity (71.6 µmoL/g d.m.). The in vivo effect of 60 days bread consumption on the immune response was studied by means of a murine model of elderly mice. Serum cytokines and intraepithelial lymphocyte immunophenotype from the mice intestine were analysed as markers of systemic and intestinal inflammatory status, respectively. Analysis of immune parameters in intraepithelial lymphocytes showed significant differences among the two types of bread indicating a positive effect of the wheat-lentil bread on the intestinal immune system, whereas both breads induced a reduction in serum IL-10.

Impact of sodium reduction strategies on volatile compounds, sensory properties and consumer perception in commercial wheat bread.

The efficacy of two sodium reduction strategies in preserving sensory profile and consumer liking of yeasted wheat bread was tested, by combining sensory data, aroma compounds and consumer investigations. The use of (i) a reduced-sodium salt substitute, Pansalt® (NaCl 57%, other salts and minor ingredients) at 1.5%, and (ii) the heterogeneous NaCl distribution (average level of 1%) leading to enhanced saltiness by taste contrast, were compared with standard (1.5%) and reduced (1.0%) addition of NaCl. The heterogeneous NaCl distribution was effective in preserving saltiness. Salt substitution with Pansalt® was less effective but preserved the overall flavour. Higher amount of Maillard reaction volatile products, associated with more intense toasted odour of the crust, was found in breads with higher NaCl content. The consumer survey highlighted satisfactory results of Pansalt® use for 58% of the respondents (equal or higher liking and purchase intention). Heterogeneous salt distribution was effective for 31% of consumers.

A Survey of Sodium Chloride Content in Italian Artisanal and Industrial Bread.

A nationwide survey on salt content in both artisanal and industrial bread was undertaken in Italy to establish a baseline for salt reduction initiatives. Excess sodium intake in the diet is associated with high blood pressure and the risk of cardiovascular diseases. Bread has been identified as a major contributor to salt intake in the Italian diet. Most of the bread consumed in Italy comes from artisanal bakeries so 135 artisanal bread were sampled in 56 locations from Northern to Southern Italy together with 19 samples of industrial bread representative of the entire Italian production. Sodium chloride content was analysed according to the Volhardt's method. A salt content between 0.7% and 2.3% g/100 g (as is basis) was found, with a mean value of 1.5% (Standard Deviation, 0.3). However, the majority of samples (58%) had a content below 1.5%, with 12% having a very low salt content (between 0.5% and 1.0%), whereas the remaining 42% had a salt content higher than the mean value with a very high salt content (>2.0%) recorded for 3% of samples. As regards the industrial bread, an average content of 1.6% was found (SD, 0.3). In this group, most of the samples (56%) had a very high content between 2.0% and 2.5%, whereas 5% only had a content between 1.1% and 1.5%. Statistics on salt content are also reported for the different categories of bread.

Bioaccessible selenium in Italian agricultural soils: Comparison of the biogeochemical approach with a regression model based on geochemical and pedoclimatic variables.

Biogeochemical mapping of selenium in Italian agricultural soils was accomplished by measuring the Se concentration of representative samples of wheat grains from 71 provinces. The range of the concentration values averaged on a provincial basis was 7-245 ng Se g(-1). A multiple regression model based on six geochemical and pedoclimatic variables was developed to interpret the observed data and to predict Se concentration of wheat in areas where analytical data were missing and in the different Italian soil regions. The statistical model explained only part of the observed variance, but succeeded in identifying Se-enriched as well as Se-depleted areas with an acceptable level of agreement with the biogeochemical map based on measured Se in wheat. Furthermore, the model showed that within the range of concentrations measured in Italian soils, Se-bioaccessibility is controlled not only by the Se content of the soil parent rocks, but also by their overall geochemical nature (carbonatic vs. silicatic) and by pedoclimatic variables (temperature and rain intensity excursions) related to fluctuations of soil moisture and pH. Overall, several Se-marginal and Se-deficient areas were identified on the Italian territory. The implications of these findings for public health are discussed briefly.

Polyphenols in Raw and Cooked Cereals/Pseudocereals/Legume Pasta and Couscous.

Pasta and couscous are popular foods manufactured (in their traditional form) from durum wheat semolina. In recent years, the consumers' quest for novel, functional, gluten-free, wholegrain foods has prompted the industry to manufacture new pasta and couscous products in which durum wheat has been partially or totally replaced by other vegetable flours. Besides dietary fibre, these raw materials might be an interesting source of phytochemicals. In this work, 16 commercial samples of pasta and four samples of couscous representative of the new products and made of refined and wholegrain flours of different species of cereals, pseudocereals and legumes were analysed for free, hydrolysable bound and total polyphenol content by means of the Folin-Ciocalteu procedure. Analyses were repeated on cooked samples to assess the quantity of polyphenols ingested by the consumers. The raw legume and pseudocereal products had a total polyphenol content higher than most cereal products (up to 1743.4 mg of Gallic Acid Equivalent (GAE) per 100 g dry weight). Wholegrain products had higher contents than refined products. The free fraction underwent up to 46% loss with cooking, probably because of solubility in water. The water absorption of pasta and couscous during cooking was in a ratio of 2:3, resulting in higher dilution of polyphenols in the cooked couscous.

Improvement of a headspace solid phase microextraction-gas chromatography/mass spectrometry method for the analysis of wheat bread volatile compounds.

An improved method based on headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS) was proposed for the semi-quantitative determination of wheat bread volatile compounds isolated from both whole slice and crust samples. A DVB/CAR/PDMS fibre was used to extract volatiles from the headspace of a bread powdered sample dispersed in a sodium chloride (20%) aqueous solution and kept for 60min at 50°C under controlled stirring. Thirty-nine out of all the extracted volatiles were fully identified, whereas for 95 other volatiles a tentative identification was proposed, to give a complete as possible profile of wheat bread volatile compounds. The use of an array of ten structurally and physicochemically similar internal standards allowed to markedly improve method precision with respect to previous HS-SPME/GC-MS methods for bread volatiles. Good linearity of the method was verified for a selection of volatiles from several chemical groups by calibration with matrix-matched extraction solutions. This simple, rapid, precise and sensitive method could represent a valuable tool to obtain semi-quantitative information when investigating the influence of technological factors on volatiles formation in wheat bread and other bakery products.

Nutritional characterisation and bioactive components of commercial carobs flours.

Food industry is interested in the utilisation of legume flours for the improvement the nutritional quality of cereal based foods. In this context, this research aimed at investigating the beneficial properties of different commercial carob seed flours -Ceratonia siliqua L.-. In particular, we determined chemical parameters (protein, fat, ash, soluble and insoluble fibre) by standard AOAC methods, lignans (secoisolariciresinol, lariciresinol, isolariciresinol, pinoresinol) by HPLC methods, the Total Polyphenol Content (TPC) by the Folin Ciocalteau method and the antioxidant properties by the FRAP assay. The carob germ flour and the raw carob seed flour reached the highest insoluble fibre, lignan and total polyphenols content and these results were matched by their antioxidant properties. Different carob flours showed a different distribution of the various lignans.

Phenols, lignans and antioxidant properties of legume and sweet chestnut flours.

Total phenols (TPC) and antioxidant properties were determined in chick-pea, green and red lentils and sweet chestnut flours, in both aqueous-organic extracts and their residues, by the Folin Ciocalteau method and by the FRAP assay, respectively. Plant lignans were quantified in flours by means of HPLC. In addition, the FRAP of plant lignans (secoisolariciresinol, lariciresinol, isolariciresinol, pinoresinol, matairesinol), their mixture and enterolignans (enterodiol and enterolactone) were determined. In all flours, the highest TPC values were found in the residue. Specific and varietal significant differences were observed in all parameters. The highest TPC (737.32 and 1492.93mg/100gd.w.) and FRAP (140.32 and 101.25µmol/gd.w.) values were reached by green lentils in both aqueous-organic extract and residue, respectively. Sweet chestnuts had the highest total lignans (980.03µg/100gd.w.). It was also found that the plant lignans standards have a higher antioxidant activity than enterolignans standards and that matairesinol has the highest activity.

Lignan Content in Cereals, Buckwheat and Derived Foods.

Cereal foods are a fundamental part of a balanced diet and several studies have assigned to wholemeal cereal products a protective role in human health, due to their content of bioactive compounds. Within the phytochemicals, lignans are of increasing interest for their potential anticarcinogenic, antioxidant, estrogenic and antiestrogenic activities. The aim of this work is to contribute to the updating of food lignan databases by providing the profile and the amount of lignans in cereals, buckwheat and several cereal based foods commonly consumed in human diets. Values were taken from published papers. Items were divided in different groups, namely grains, brans andflours, bread, cereal staple foods, breakfast cereals and other cereal products, and values for secoisolariciresinol, matairesinol, pinoresinol, lariciresinol are given. For example, the total average values for the mentioned lignans in grains ranged between 23 µg/100 g and 401 µg/100 g dry weight. The contribution of each single lignan molecule to the total value of lignans appears to be different for every cereal species. Lignan content and typology in processed foods depends on the raw materials used, their degree of refinement and on processing conditions.

Arsenic contamination of the environment-food chain: a survey on wheat as a test plant to investigate phytoavailable arsenic in Italian agricultural soils and as a source of inorganic arsenic in the diet.

Seven hundred and twenty-six samples of wheat grains from the majority of Italian agricultural areas were pooled into 141 composite samples, homogeneous with respect to geographical origin and wheat variety. The average arsenic concentration of the pooled samples was 9 ng g(-1), with a range of 2-55 ng g(-1) (dry weight basis). The spread of arsenic concentrations (coefficient of variation of 91%) was related to spatial variability associated with geochemical and environmental factors. Temporal variability was investigated by a 3-year longitudinal study on 7 wheat cultivars grown in 22 areas of central and northern Italy. Average year-to-year variation in arsenic levels was low, and the average of the coefficients of variation was 23%. These results show that mapping of phytoavailable arsenic in agricultural soils can be done by measuring arsenic concentration in representative samples of wheat grains. Arsenic speciation in the grain showed that As(III) and As(V) were the major As compounds, highlighting the importance of wheat as a source of inorganic arsenic in the diet.