D. Sgrulletta

Effects of high-temperature drying on technological properties of pasta.

Spaghetti samples of five Italian durum wheat cultivars were dried at two different temperatures (LT = 50 °C and HT = 90 °C) and then evaluated in relation to various quality parameters. All samples processed at LT were given low quality scores on the basis of the organoleptic judgement. The use of higher temperatures resulted in improved cooking quality; however, the magnitude of this improvement differed between cultivars, and only in two cases did the HT treatment assure a good cooking quality. No significant differences in beta-carotene content were found between spaghetti samples dried at LT and at HT. However, the surface of spaghetti processed at HT showed a more intense yellow colour (yellow index). Higher drying temperatures resulted in increased amounts of protein insoluble in 0·1 M acetic acid. A strong, highly significant correlation ( r = 0·99, P

Use of near infrared reflectance and transmittance coupled to robust calibration for the evaluation of nutritional value in naked oats

A rapid accurate and precise method for simultaneous determination of β-glucan and protein content in naked oat samples, based on the coupling of near-infrared spectroscopy and chemometrics, is presented. In particular, three different spectroscopic approaches [near infrared reflectance (NIR) and transmittance (NIT) on flour and NIT on whole grains] and various spectral pretreatments were considered. To account for the possibility of outlying samples, a robust version of the PLS algorithm (namely partial robust M-regression) was used. All the models resulted as accurate as the reference methods, reflectance spectroscopy being the technique providing the best outcomes. Variable reduction by inclusion of the most relevant predictors only (as evaluated by VIP scores) resulted in simpler and, in one case, more parsimonious models, without loss in accuracy.

Relationship between pasta cooking quality and acetic acid-insoluble protein of semolina

Twenty-two durum wheat semolina samples from varieties representing a wide range of pasta cooking quality, and having a wide range of protein contents, were analysed for their contents of 0·1 m acetic acid-insoluble residue protein (IR). A good correlation was found between pasta cooking quality and IR, suggesting that determination of IR might be a useful technique for selecting for good pasta-making quality during the early stages of plant breeding programmes.

Variations in Content and Extractability of Durum Wheat (Triticum turgidum L. var durum) Arabinoxylans Associated with Genetic and Environmental Factors

Arabinoxylans (AX) represent the most abundant components of non-starch polysaccharides in wheat, constituting about 70% of cell wall polysaccharides. An important property of AX is their ability to form highly viscous water solutions; this peculiarity has a significant impact on the technological characteristics of wheat and determines the physiologically positive influence in consumption. Durum wheat (Triticum turgidum L. var durum), the raw material for pasta production, is one of the most important crops in Italy. As part of a large project aimed at improving durum wheat quality, the characterization of the nutritional and technological aspects of whole grains was considered. Particular attention was addressed to identify the best suited genotypes for the production of innovative types of pasta with enhanced functional and organoleptic properties. The objective of the present study was to investigate the genetic variability of AX by examining a group of durum wheat genotypes collected at two localities in Italy for two consecutive years. The environmental influence on AX content and extractability was also evaluated. Variability in the AX fraction contents was observed; the results indicated that AX fractions of durum wheat grain can be affected by the genotype and environment characteristics and the different contribution of genotype and environment to total variation was evidenced. The genotype × environment (G × E) interaction was significant for all examined traits, the variations due to G × E being lower than that of genotype or environment. The data and the statistical analysis allowed identification of the Italian durum wheat varieties that were consistently higher in total arabinoxilans; in addition, principal component analysis biplots illustrated that for arabinoxylan fractions some varieties responded differently in various environment climatic conditions.

Effects of genetic and agronomic factors on grain composition in oats

The effects of genetic variability and agronomic practises on the chemical compounds of the grain were evaluated in a set of oat cultivars (16 naked and four husked) grown in different experiments in the years 2004–2008. In the first experiment, carried out for two years, β-glucan and Total Dietary Fibre (TDF) from eight oat cultivars, grown under three different levels of nitrogen fertilization and two seed doses, were considered. The second experiment, involving 12 cultivars for two years, explored the variation of β-glucan solubility and further characterized six cultivars for the content of TDF and arabinoxylans. In both experiments, genotype was found to exert the largest effect on the grain composition; nitrogen levels and seed doses had positive significant effects on protein and β-glucan contents, but did not affect fibre content. Among the naked cultivars, Irina, Abel, Luna, Hendon and Expression showed a good ability to accumulate the examined grain compounds. However, in general, the highest contents of protein and β-glucan were found in the groats of husked cultivars, suggesting that specific breeding programs are a crucial step to identify the suitable naked oat genotypes to produce foods of high nutritional value.

Effect of cultivar and nitrogen fertilizer on agronomic and quality traits of durum wheat under organic management

Quantitative performance as well as product quality traits among a group of durum wheat cultivars developed and selected in different eras from 1915 to 2003 were examined in an south Italian growing region under organic management. Experiments were conducted over four years. Fertilization treatments included the application of 80 kg organic nitrogen (N) fertilizer and fertilization by only the N residue from leguminous pre-crop. Genetic, agronomic and environmental effects for the investigated traits and significant interactions between factors were found. Application of organic N fertilizer increased grain yield and protein concentration, the mean increase compared to the treatment without applied fertilizer was 14.8% and 12.0%, respectively. Moreover, a significant improvement of gluten quality was observed for higher N availability. Significant cultivar by treatment interactions were observed for all quality traits. Cultivars significantly differed in grain yield and semolina protein content; mean values ranged from 2.54 to 3.50 t/ha and from 10.83 to 11.91% d.m., respectively. Modern cultivars showed the highest values. Although, significant cultivar by environment interactions were detected for agronomic and quality traits, cultivars with a stable high performance in regard to grain yield and semolina protein could have been identified. These results evidenced different adaptability of “old” and “modern” cultivars to organic production and identified only one of the “modern” cultivars as suitable to use organic nutrients in order to achieve high grain yield and quality.

Heat stress in relation to protein redox status and quality traits of durum wheat

In this study elevated temperature effects on protein quality parameters and in particular on protein sulfhydryl-disulfide contents were assessed. Four Italian durum wheat cultivars which differed for the qualitative trait changes produced by heat stress were employed. During grain filling two different thermal regimes were imposed on the plants grown in a typical area of durum wheat cultivation (Southern Italy). Results confirmed significant effects of high temperatures on the quality of products in the durum wheat chain and indicated that elevated temperatures determined changes on protein redox status, particularly evident on S-S bond content. For most of the examined traits significant cultivar x treatment interactions were also evidenced.