From seed to cooked pasta: influence of traditional and non-conventional transformation processes on total antioxidant capacity and phenolic acid content.

The aim of this work was to compare the traditional with a non-conventional (i.e. kernel micronisation) durum wheat milling process by monitoring the content of bound, conjugated and free phenolic acids (PAs) and the level of the total antioxidant capacity (TAC) occurring in the durum wheat pasta production chain, from seed to cooked pasta. The traditional transformation processes negatively influenced TAC and PA content (40% and 89% decrease from seed to cooked pasta, respectively), mainly during the milling process (25% and 84% decrease of TAC and PA, respectively), which has been related to the removal of external layers of kernels. Conversely, the micronisation applied on durum wheat kernels allowed to obtain whole-wheat pasta that preserved the seed endowment of antioxidant compounds even in cooked pasta. These results indicate the micronisation as a valuable approach to produce pasta with improved nutritional value and potential health-promoting effects compared to the traditional pasta.

The starch-bound alpha-amylase/trypsin-inhibitors in Avena.

Oat kernels exhibit an extra-soft texture, a trait recently demonstrated to be largely modulated by starch-bound tryptophan-rich 2S proteins, the vromindolines. In this study, fractionation by two-dimensional electrophoresis of starch-bound proteins in 25 oat (Avena sativa) cultivars and 11 diploid or tetraploid Avena species revealed novel 2S proteins called Avena α-amylase/trypsin-inhibitors (AATI) because of their sequence similarity with wheat α-amylase/trypsin inhibitors. Thirty-seven AATI polypeptides, about 14 kDa in size, were split into three families named AATI-1, AATI-2, and AATI-3 with different primary structures and isoelectric points. AATI-1 and AATI-2 proteins showed 55.5-60.0 % sequence similarity with wheat α-amylase inhibitors CM1, CM2, and CM16, which have been found to cause innate immunity responses in celiac disease and non-celiac gluten sensitivity. Diploid A-genome and tetraploid AC-genome oat species possess three and five genes encoding for the AATI proteins, respectively, whereas hexaploid A. sativa exhibits 12 genes dispersed over the A-, C-, and D-genomes. Some AATI proteins expressed in hexaploid oats were assigned to the A-genome based on similarity to their counterparts in diploid species, contributing to further clarify the genetic origin of hexaploid oats. Moreover, AATI may interact with starch-bound vromindolines in determining the extra-soft texture of oat kernels and, due to their balanced amino acid compositions, may contribute to the biological value of oat proteins in a positive manner.

Biochemical and molecular characterization of Avena indolines and their role in kernel texture.

Among cereals, Avena sativa is characterized by an extremely soft endosperm texture, which leads to some negative agronomic and technological traits. On the basis of the well-known softening effect of puroindolines in wheat kernel texture, in this study, indolines and their encoding genes are investigated in Avena species at different ploidy levels. Three novel 14 kDa proteins, showing a central hydrophobic domain with four tryptophan residues and here named vromindoline (VIN)-1,2 and 3, were identified. Each VIN protein in diploid oat species was found to be synthesized by a single Vin gene whereas, in hexaploid A. sativa, three Vin-1, three Vin-2 and two Vin-3 genes coding for VIN-1, VIN-2 and VIN-3, respectively, were described and assigned to the A, C or D genomes based on similarity to their counterparts in diploid species. Expression of oat vromindoline transgenes in the extra-hard durum wheat led to accumulation of vromindolines in the endosperm and caused an approximate 50 % reduction of grain hardness, suggesting a central role for vromindolines in causing the extra-soft texture of oat grain. Further, hexaploid oats showed three orthologous genes coding for avenoindolines A and B, with five or three tryptophan residues, respectively, but very low amounts of avenoindolines were found in mature kernels. The present results identify a novel protein family affecting cereal kernel texture and would further elucidate the phylogenetic evolution of Avena genus.

Nutritional Traits, Pasting Properties and Antioxidant Profile of Selected Genotypes of Sorghum, Oat and Maize Eligible for Gluten-Free Products.

The technological and nutritional traits of food-grade sorghum hybrids, hulled/naked oat varieties and maize genotypes of different colors were studied for novel and healthier gluten-free foods. Oat genotypes showed the highest protein content, followed by maize and sorghum. The total starch and the total dietary fiber content were quite similar among the three species. Great variation was found in the amylose content, and the highest was in sorghum (27.12%), followed by oat 16.71% and maize 10.59%. Regarding the pasting profile, the rank of Peak Viscosity was sorghum (742.8 Brabender Unit, BU), followed by maize (729.3 BU) and oat (685.9 BU). Oat and sorghum genotypes had similar average breakdown (407.7 and 419.9 BU, respectively) and setback (690.7 and 682.1 BU, respectively), whereas maize showed lower values for both parameters (384.1 BU and 616.2 BU, respectively). The total antioxidant capacity, only in maize, significantly correlated with total flavonoid, phenolic and proanthocyanidin contents, indicating that all the measured compounds contributed to antioxidant capacity. The study indicated the importance of sounding out the nutritional and technological characteristics of gluten-free cereals in order to select suitable cultivars to be processed in different gluten-free foods with better and healthier quality.

Valorization of Two African Typical Crops, Sorghum and Cassava, by the Production of Different Dry Pasta Formulations.

Mediterranean diet is changing to keep up with the increasingly multiethnic Italian society. With food being considered as a means of integration, innovative foods capable of mixing different raw materials could be of interest. In this work, some of the most consumed African foods such as sorghum, cassava, and durum wheat were used to produce wholegrain spaghetti to valorize their nutritional and sensorial aspects and to combine Italian and foreign tastes. Different pasta formulations (cassava, semolina, cassava:semolina, cassava:sorghum, cassava:durum wheat whole meal, sorghum:semolina) were developed and compared for their content of proteins, total starch, resistant starch, amylose, fiber, total antioxidant capacity, ash, cooking quality and sensorial characteristics. The enrichment of cassava flour with durum wheat and sorghum wholegrain enhanced the total antioxidant capacity, protein, and fiber content with respect to 100% cassava pasta. The presence of cassava or sorghum resulted in a high diameter variability of pasta samples, lower water absorption, and shorter optimal cooking time with respect to semolina pasta. Sensory evaluation of cooked pasta revealed better scores in blends containing semolina. Although the obtained pasta samples were interesting for their nutritional aspects, further adjustments are required in the pasta-making process to improve pasta quality.

Ancient Caucasian Wheats: A Contribution for Sustainable Diets and Food Diversity.

Through the centuries, the domestication and modern breeding of wheat led to a significant loss of genetic variation in the cultivated gene pool with a consequent decrease in food diversity. Current trends towards low-input and sustainable agriculture call for the revitalization and exploitation of ancient wheats, which represent a reservoir of biodiversity useful to ensure sustainable wheat production in the context of climate change and low-input farming systems. Ancient Caucasian wheat species, such as the hulled wheats Triticum timopheevii (tetraploid AuAuGG) and Triticum zhukovskyi (hexaploid AuAuAmAmGG), are still grown to a limited extent in the Caucasus for the production of traditional foods. These Caucasian wheats were grown in Italy and were analyzed for physical, nutritional and technological characteristics and compared to durum wheat. Both Caucasian species revealed a high protein content (on average 18.5%) associated with a low gluten index, mainly in T. zhukovskyi, and test weight values comparable to commercial wheats. The total antioxidant capacity was revealed to be the double of that in durum wheat, suggesting the use of ancient Caucasian wheats for the production of healthy foods. Finally, the technological and rheological results indicated that Caucasian wheats could be potential raw material for the formulation of flat breads, biscuits and pasta.

Cooking Quality and Chemical and Technological Characteristics of Wholegrain Einkorn Pasta Obtained from Micronized Flour.

The increased demand for healthier foods, the recognition of dry pasta as an ideal carrier of functional ingredients, and the current interest for ancient wheats such as einkorn motivated the present research. Two varieties of Triticum monococcum, namely cv Norberto and the free-threshing cv Hammurabi, were milled by ultra-fine milling process (micronization) to produce wholegrain spaghetti. Einkorn pasta was assessed in terms of technological and biochemical properties and cooking and sensorial quality and compared to durum wheat semolina pasta. Wholewheat einkorn pasta showed a threefold increase in total dietary fibre content as well as in total antioxidant capacity in comparison to the control. The level of resistant starch in cv Norberto resulted significantly higher respect to semolina and einkorn cv Hammurabi pasta. Despite the very weak einkorn gluten network, the sensory and instrumental assessment of pasta quality highlighted that einkorn spaghetti presented good sensorial properties related to their technological quality, in particular, for the overall judgment and firmness. Cultivar Hammurabi emerged as the preeminent compromise on the basis of technological performances together with chemical and sensorial aspects.

Innovative Milling Processes to Improve the Technological and Nutritional Quality of Parboiled Brown Rice Pasta from Contrasting Amylose Content Cultivars.

The demand for gluten-free products, including pasta, is increasing and rice pasta accounts for the largest share of this market. Usually, the production of rice pasta requires additives or specific technological processes able to improve its texture, cooking quality, and sensory properties. In this work, two rice cultivars, with different amylose content, were subjected to parboiling, micronization, and flour air fractionation to obtain brown rice pasta, without any supplement but rice itself. In particular, two types of pasta (spaghetti shape) were produced, one from 100% micronized wholemeal, and the other from refined rice flour replaced with 15% of the air-fractionated fine fraction. Regardless of the cultivar, pasta from wholemeal micronized flour showed higher protein and fiber content than refined flour enriched with fine fraction, whereas no differences were revealed in resistant starch and antioxidant capacity. Pasta from the high amylose content genotype showed the highest resistant starch content and the lowest predicted glycemic index along with sensorial characteristics as good as durum semolina pasta in fine fraction enriched pasta. Besides the technological processes, pasta quality was affected the most by the genotype, since pasta obtained from high amylose cv Gladio resulted in the best in terms of technological and sensory quality.

Using Einkorn and Tritordeum Brewers' Spent Grain to Increase the Nutritional Potential of Durum Wheat Pasta.

Brewers' spent grain (BSG), the major by-product of the brewing industry, can be used as a functional ingredient to increase the nutritional value of cereal-based products. In this work, micronized BSG from the einkorn and tritordeum brewing processes were characterized and used to produce four macaroni pasta formulations enriched with BSG at ratios of 5 g and 10 g/100 g of semolina. Einkorn BSG showed the highest values for all the parameters analyzed-proteins, total dietary fiber (TDF) and total antioxidant capacity (TAC)-except for ß-glucan. TDF increased up to 42 and 68% in pasta samples enriched with 10% of BSG from tritordeum and einkorn, respectively. The replacement of 10% of semolina with BSG from both cereals significantly increased the ß-glucan content and TAC values. Finally, the addition of BSG from einkorn and tritordeum affected to a minimal extent the sensory properties of cooked pasta, which showed higher values of optimal cooking time and cooking loss, but lower total organic matter compared to semolina pasta. Results from the sensorial judgment fell in the good quality ranges for durum wheat pasta; the incorporation of 10% of einkorn BSG resulted in the best compromise in terms of technological, nutritional and sensorial aspects of enriched pasta.

Traditional and Non-Conventional Pasta-Making Processes: Effect on In Vitro Starch Digestibility.

Pasta is a carbohydrate-rich food with a low glycemic index (GI) and is one of the main sources of slowly digestible starch (SDS). The presence of bran fractions (BFs) in pasta may enhance its health potential, owing to the content of fiber, micronutrients, and bioactive compounds; however, at the same time, BF may affect starch digestibility. In this study, the bioaccessibility of starch in pasta made with BF-enriched semolina (BF pasta), or only with micronized debranned kernel (DK pasta), and a control pasta made with traditional semolina was evaluated by applying two different in vitro models. The control pasta showed a percentage of SDS about four-fold higher than that of the BF pasta and 1.5-fold higher than that of the DK pasta (p < 0.05). The amount of starch released during simulated gastrointestinal digestion was slightly lower, but not significantly different, for the control pasta than for both the BF and DK pasta. These results suggest that the presence of a higher amount of dietary fiber in BF pasta can affect the structure of the food matrix, interfering with the formation of the gluten network, water absorption, and starch granule accessibility, while micronization could enhance starch digestibility due to starch gelatinization. These findings emphasize the need to optimize the process for producing fiber-rich pasta without affecting its low starch digestibility and, consequently, its GI.

Starch-bound 2S proteins and kernel texture in einkorn, Triticum monococcum ssp monococcum.

The starch granule proteins from 113 einkorn wheat (Triticum monococcum ssp monococcum) accessions were analyzed by acidic, polyacrylamide gel electrophoresis (A-PAGE), and two-dimensional A-PAGE x SDS-PAGE. All accessions were confirmed to contain equal amounts of two polypeptide chains corresponding to puroindoline B (Pin-B), as well as a prominent component plus a faint band corresponding to puroindoline A (Pin-A). When compared with soft-textured common wheat, "monococcum" accessions showed an increase of 3.2- and 2.7-fold in Pin-A and Pin-B levels on the starch granules, respectively. In addition, all accessions contained a novel component of the 2S super-family of seed proteins named Einkorn Trypsin Inhibitor (ETI), which was found to be encoded as a pre-protein 148 residues long. Wild-type ETI encoded by allele Eti-A(m) 1a and "valine-type" ETI encoded by allele Eti-A(m) 1b, which occurred in 107 and six einkorn accessions, respectively, were found to accumulate on starch granules as a mature protein of 121 amino acids with a hydrophobic central domain. The einkorn accessions exhibited an average SKCS index as low as -2.05 +/- 11.4, which is typical of extra-soft kernels. The total surface area of starch granules in "monococcum" wheat, as determined by visual assessments in counting chambers, was estimated at 764 mm(2)/mg of starch, and was about 1.5 times higher than that for common wheat. The results are discussed in relation to the identification of factors that cause the extra-soft texture of einkorn kernels.

How do conventional and organic management affect the healthy potential of durum wheat grain and semolina pasta traits?

The effect of cropping system (conventional vs. organic) and soil tillage (conventional vs. reduced tillage) on the health potential of durum wheat grain as well as on semolina and pasta quality traits was investigated in a long-term field experiment. Total antioxidant capacity, total arabinoxylans, alkylresorcinols, yellow pigments and total phenolics, which were assessed in kernels, revealed differences between the two cultivation systems only in 2011, whereas in the 2010 rainy season, cropping management did not influence these compounds. Proteins and W index were higher in the conventional system, except for the exceptionally rainy years. In contrast, the quality of cooked spaghetti was comparable in both management systems. Soil tillage differently affected bioactive compounds but had no impact on semolina and pasta quality. Overall, climatic conditions was the major factor affecting the quality of durum wheat. Our results indicate that an organic system does not represent a constraint to obtaining durum wheat grain with healthy potential relative to conventional wheat.

Bioactive composition and sensory evaluation of innovative spaghetti supplemented with free or α-cyclodextrin chlatrated pumpkin oil extracted by supercritical CO2.

The feasibility of producing durum wheat pasta enriched with a lipophilic phytocomplex, extracted using supercritical carbon dioxide (SC-CO2), from ripe pumpkin, as free oil or as ready-to-mix oil/α-cyclodextrins (α-CDs) powder, was explored. Four types of pasta were prepared: (i) control spaghetti (S-CTRL); (ii) spaghetti supplemented with α-CDs (S-α-CD); (iii) spaghetti supplemented with pumpkin oil (S-Oil) and (iv) spaghetti supplemented with the pumpkin oil/α-CD powder (S-Oil/α-CD). The chemical, antioxidant, textural and sensory attributes of the different pasta were evaluated and compared. S-Oil and S-Oil/α-CD spaghetti were significantly enriched with phytosterols, squalene, carotenoids, tocochromanols and unsaturated fatty acids. Spaghetti containing α-CDs were slightly improved in terms of fiber content. Oil chlatration increased the stability of some bioactives during pasta production and ameliorated poor textural and sensory characteristics of the cooked spaghetti compared with S-Oil sample. S-Oil/α-CD spaghetti might be accepted by customers, if the potential health benefits were also explained.

GWAS for Starch-Related Parameters in Japonica Rice (Oryza sativa L.).

Rice quality is mainly related to the following two starch components, apparent amylose content (AAC) and resistant starch (RS). The former affects grain cooking properties, while RS acts as a prebiotic. In the present study, a Genome Wide Association Scan (GWAS) was performed using 115 rice japonica accessions, including tropical and temperate genotypes, with the purpose of expanding the knowledge of the genetic bases affecting RS and AAC. High phenotypic variation was recorded for the two traits, which positively correlated. Moreover, both the parameters correlated with seed length (positive correlation) and seed width (negative correlation). A correlational selection according to human preferences has been hypothesized for the two starch traits and grain size. In addition, human selection has been proposed as the causal agent even for the different phenotypes related to starch and grain size showed by the tropical and temperate japonica accessions utilized in this study. The present GWAS led to the identification of 11 associations for RS on seven chromosomes and five associations for AAC on chromosome 6. Candidate genes and co-positional relationships with quantitative trait loci (QTLs) previously identified as affecting RS and AAC were identified for 6 associations. The candidate genes and the new RS- and/or AAC-associated regions detected provide valuable sources for future functional characterizations and for breeding programs aimed at improving rice grain quality.

Use of bran fractions and debranned kernels for the development of pasta with high nutritional and healthy potential.

The quality of pasta produced with debranning products (bran fractions, BF, and debranned kernels, DK) of durum wheat was investigated by evaluating their total antioxidant capacity, occurrence of nutritional and bioactive compounds, and sensory properties. Two pasta samples, produced with BF-enriched semolina (BF pasta) or only with micronized DK (DK pasta), respectively, were compared with pasta made with traditional semolina (control pasta). BF pasta and DK pasta displayed significantly higher content of bioactive compounds, such as phenolic compounds and dietary fibre, than control pasta, to a different extent for the diverse compounds. The present study indicates that the debranning process allows to produce pasta with a high content of healthy compounds and minimal effects on sensory properties, using only the natural endowment of durum wheat. This approach is suitable to produce cereal-based foods with the potential nutritional and health benefits of partially refined cereals and limitation of their main drawbacks.

Identification and quantification of soluble free, soluble conjugated, and insoluble bound phenolic acids in durum wheat (Triticum turgidum L. var. durum) and derived products by RP-HPLC on a semimicro separation scale.

A straightforward semimicro separation scale RP-HPLC method was developed for the identification and quantification of phenolic acids (PAs) occurring as soluble free, soluble conjugated, and insoluble bound compounds, which were independently extracted from wholemeal of durum wheat and from its derived products coarse bran, semolina, and dried pasta. A narrow bore column and a semimicro photodiode array detector (PDA) cell, in conjunction with a single quadrupole mass spectrometer, equipped with an electrospray ionization source (ESI-MS), were employed. The method was validated in terms of linearity of calibration graphs, limits of detection, limits of quantification, repeatability, and accuracy, which was evaluated by a recovery study. In each sample (wholemeal, coarse bran, semolina, and dried pasta), the total amounts of the three different forms of PAs were in the order bound > conjugated > free, with bound PAs accounting for 61.0-83.6% of the total PAs. Ferulic acid was the most abundant PA in both soluble free and insoluble bound forms, whereas sinapic acid predominated in the conjugated ones. The highest PA content, calculated as the sum of total PAs quantified in the three forms, was found in coarse bran, followed by wholemeal, semolina, and dried pasta.