1. Introduction

After the massive use of processed acorns, as food source for prehistoric nomadic populations, the most important food discovery was undoubtedly that of cereals. Even now, wheat (Triticum) is one of the main food sources in the world. According to the last FAO report, wheat world production for 2017 was approximately expected in 740 million tons, exceeding the previous last one crop year by 1.2%, and covering about 15% of the world's arable surface [1]. In this scenario, durum wheat production reaches around 30 million tons, accounting approximately for 5–6% of the total world wheat production [2]. Canada, USA, Mexico and Russia are some of the countries around the world where durum wheat is cropped, although the Mediterranean region covers about 60% of world durum wheat production [3], being the EU (Italy, Spain, France and Greece) the leading global producer [2]. South Italy is one of the regions historically most voted to the cereal crops, where the durum wheat varietal biodiversity is particularly high [4].

Moreover, computerized image analysis techniques were applied to compare glume wheat

Phenolic Fingerprinting and Glumes Image Analysis as an Effective Approach for Durum Wheat Landraces…

Nine durum wheat (Triticum durum Desf.) landraces ("Margherito," "Manto di Maria," "Ruscia," "Russello SG8," "Scavuzza," "Tumminia SG3," "Trentino," "Tripolino," "Urria")

consecutive years (2012, 2013, 2014), in the fields of the Stazione Sperimentale di Granicoltura

Sicily, Italy). 40 kg N/ha and 90 kg P2O5/ha were supplied at sowing carried out at the beginning of December; nitrogen fertilization with 50 kg N/ha were applied before the beginning of stem elongation stage (20–30 code in the BBCH-scale for cereals). Mechanical weed control methods were carried out in spring time and harvest was performed when physiolog-

Whole grain samples were milled to a fine powder by a laboratory mill (1093 Cyclotec Sample Mill, Tecator Foss, Hillerød, Denmark) equipped with a 1 mm sieve, immediately cooled to �20�C and kept at this temperature until analysis to protect bioactive components from

All solvents and reagents used in this study were high purity laboratory solvents by Carlo Erba (Milano, Italy); HPLC grade water and acetonitrile were obtained from VWR (Milano, Italy). Pure vitexin (apigenin 8-C-glucoside) and orientin (luteolin 8-C-glucoside) were provided by Extrasynthese (Lyon, France) whilst vanillic acid, ferulic acid, p-coumaric acid and

Phenolic acids and flavonoids represent the most common form of phenolic compounds found in whole grains, existing as soluble free compounds, soluble conjugates esterified to sugars and other low molecular mass components, and insoluble bound forms either encapsulated in

According to Lo Bianco et al. [11], free phenolics were recovered by applying the method proposed by Dinelli et al. [14] with few changes. In brief, 1 g of whole wheat flour was mixed

caffeic acid were purchased from Sigma (Sigma-Aldrich s.r.l., Milano, Italy).

the cell-wall structures or chemically bound at molecular level [15].

1200N; 14�31<sup>0</sup>

, during three

25

1700E; 313 m a.s.l.] (CT,

http://dx.doi.org/10.5772/intechopen.79595

samples, implementing a statistical classificator able to discriminate the landraces.

Grains were cropped, in three plots of 10 m<sup>2</sup> each, using 350 viable seeds/m<sup>2</sup>

2. Materials and methods

2.1. Polyphenolic profile analysis

were selected for phenolics profile evaluation.

ical maturity of each genotype was reached.

2.1.3. Extraction of free and bound phenolic compounds

per la Sicilia, sited in Santo Pietro - Caltagirone [37�07<sup>0</sup>

2.1.1. Samples details

degradation [14].

2.1.2. Chemicals

For geographical position and ecological condition, Sicily represents the perfect environment for the cultivation of cereals, especially for durum wheat. In addition to the pedo-climatic conditions [5], some historical and socio-cultural aspects had also contributed to enrich the varietal heritage, such as the many invasions that characterized the island during the centuries. All these conditions, together with the historically conducted mass selection and the more recent genetic improvement programs based on the artificial crosses, had contributed to build the extremely wide currently existing varietal panorama [4].

In Sicily, old and new durum wheat commercial varieties are currently cropped, but also many ancient landraces or populations characterized by specific bio-morphological traits and qualitative features [6, 7].

In recent years, all over the world, the attention paid to local and traditional productions is growing, especially in the agro-food sector. Maybe, it is due to the impact of globalization and the social and economic changes, but also to the increased consideration to health and nutritional aspects of food. Also in Sicily, this trend has led to the rediscovery and reuse of landraces both of wheat and other crops, responding to requests for more and more demanding market. The rising price of these local productions are contributing to the farmers' satisfaction, changing an unprofitable job in a renewed professional opportunity also for young businessmen. Furthermore, many recent research studies testify the high healthy and nutraceutical value of landraces, both for high amount of antioxidant compounds and for their natural aptitude to organic production [8–11].

This growing interest in local landraces has inspired to find effective and objective identification methods, able to distinguish landraces [12, 13].

In this chapter a multidisciplinary practical approach based on genotype and phenotype characterization of durum wheat Sicilian landraces is proposed. In particular, the polyphenolic profile of whole wheat grains was analyzed by means of HPLC/DAD and HPLC/ESI-MS. Moreover, computerized image analysis techniques were applied to compare glume wheat samples, implementing a statistical classificator able to discriminate the landraces.
