Maria Grazia D'Egidio

Characterization of Durum Wheat Semolina by Means of a Rapid Shear-Based Method

ABSTRACT A rapid shear-based test (the GlutoPeak test, recently proposed by Brabender) was used to investigate gluten aggregation properties of durum wheat semolina and to relate them to pasta cooking behavior. Thirty semolina samples were characterized by means of the conventional approaches used for pasta-quality prediction (protein content, gluten index, and alveographic indices). All samples were also analyzed by the GlutoPeak test, obtaining three parameters: maximum peak torque, maximum peak time, and area under the peak. The GlutoPeak indices were significantly correlated with protein content, gluten index, and W alveographic parameter. The cooking quality of pasta obtained from the 30 semolina samples was evaluated by sensory analysis in terms of stickiness, bulkiness, firmness, and overall quality. The GlutoPeak indices were significantly correlated with the sensorial parameters. In comparison with the alveographic test, which is presently the most used rheological approach for semolina character...

Fructan biosynthesis and degradation as part of plant metabolism controlling sugar fluxes during durum wheat kernel maturation

Wheat kernels contain fructans, fructose based oligosaccharides with prebiotic properties, in levels between 2 and 35 weight % depending on the developmental stage of the kernel. To improve knowledge on the metabolic pathways leading to fructan storage and degradation, carbohydrate fluxes occurring during durum wheat kernel development were analyzed. Kernels were collected at various developmental stages and quali-quantitative analysis of carbohydrates (mono- and di-saccharides, fructans, starch) was performed, alongside analysis of the activities and gene expression of the enzymes involved in their biosynthesis and hydrolysis. High resolution HPAEC-PAD of fructan contained in durum wheat kernels revealed that fructan content is higher at the beginning of kernel development, when fructans with higher DP, such as bifurcose and 1,1-nystose, were mainly found. The changes in fructan pool observed during kernel maturation might be part of the signaling pathways influencing carbohydrate metabolism and storage in wheat kernels during development. During the first developmental stages fructan accumulation may contribute to make kernels more effective Suc sinks and to participate in osmotic regulation while the observed decrease in their content may mark the transition to later developmental stages, transition that is also orchestrated by changes in redox balance.

Effects of Genotype and Environment on Phenolic Acids Content and Total Antioxidant Capacity in Durum Wheat

ABSTRACT In cereals, phenolic acid (PA) content and total antioxidant capacity (TAC) may have a wide range of variability, probably because of several factors influencing the occurrence of grain antioxidants, which include genotype, environment, and their possible interactions. However, only a few studies have investigated the influence of these factors on durum wheat. In the present study, we investigated the impact of the genetic and environmental factors on the profile and content of PAs occurring as soluble free, soluble conjugated, and insoluble bound compounds, as well as on the TAC level, in three genotypes of durum wheat grown in three different Italian agroclimatic areas during two crop years. The results show that genotype, environment, and crop year have highly significant effects on TAC levels and on PA contents. In particular, TAC and free PAs are most influenced by year, whereas conjugated and bound PAs are most influenced by environment × year and genotype, respectively. Therefore, it is ev...

Quality and nutritional properties of pasta products enriched with immature wheat grain

In this study, nutritional and sensory properties of pasta enriched with 30% immature wheat grain (IWG), a natural source of fructo-oligosaccharides (FOS), are evaluated. Colour and cooking quality, nutritional value and glycaemic index (GI) of pasta were assessed in comparison with commercially enriched inulin and 100% wholewheat pastas. IWG integration induced deep changes in colour, without negatively affecting the cooking quality of pasta, and promoted nutritional quality by increasing the fibre content; IWG pasta presented a remarkable leaching of FOS in cooking water, thus providing only 1 g of FOS per serving. IWG pastas showed a GI of 67 (dried) and 79 (fresh), not significantly different from commercial pasta products. IWG can be considered an interesting ingredient to obtain functional products ‘naturally enriched’ in FOS and fibre. Results about FOS leaching suggest that, in dealing with functional effects, the actual prebiotic content should be carefully considered on food ‘as eaten’.

Variation in fructooligosaccharide contents during plant development and in different cultivars of durum wheat

Abstract Fructooligosaccharides (FOS) have received a great deal of attention for their properties as prebiotic components. Several plants store FOS in their tissues as carbohydrate source or as osmoregulators. In comparison with the other natural FOS sources, cereals, in particular durum wheat, store a significant amount of these oligosaccharides during their growth. To gain a deeper insight on the relationships between FOS and plant/kernel development, FOS levels were analysed in the grains and stems of a widely cultivated durum wheat cultivar (Simeto), during the whole period of grain filling. In addition, a broad analysis of FOS contents was carried out by comparing their levels in the stems and grains of 45 cultivars of durum wheat harvested at two development stages. Results show a large variation among cultivars in their capability to metabolise FOS.