Five durum wheat cultivars were grown in a Mediterranean area (Southern Italy) under conventional and organic farming with the aim to evaluate agronomic, technological, sensory, and sanitary quality of grains and pasta. The cultivar Matt produced the best pasta quality under conventional cropping system, while the quality parameters evaluated were unsatisfactory under organic farming. The cultivar Saragolla showed the best yield amount and pasta quality in all the experimental conditions, thus proving to be the cultivar more adapt to organic farming. In all the tested experimental conditions, nivalenol (NIV) and deoxynivalenol (DON) occurrence was very low and the other mycotoxins evaluated were completely absent. These data confirm the low risk of mycotoxin contamination in the Mediterranean climate conditions. Finally, it has been possible to produce high-quality pasta in Southern Italy from durum wheat grown both in conventional and organic farming.
Durum wheat (
The global quality of durum wheat belongs to the complex interaction between environmental conditions, yield characteristics, and technological requirements for its transformation in pasta. A worldwide agreement considers protein content and gluten quality the main factors that influence pasta quality [
The quality of durum wheat may be evaluated by more than one point of view: agronomical quality that influences potentiality and stability of grain yield; milling quality that influences semolina yield, ash content, humidity, and impurity of grains; technological quality that influences content of protein and gluten quantity and quality; hygienic and sanitary quality that are related to some phytopathological microorganisms or their secondary metabolites. Recently, the consumer is also oriented toward other meanings of quality based on environmental and ethic friendly production.
The environmental impact of pasta production has been mainly related to the cropping system, the production techniques of semolina, and the adopted packaging [
Water deficit and high temperature are the main environmental factors affecting durum wheat grain quality under Mediterranean climate. It was reported that periods of heat stress with temperatures higher than 35°C during grain filling may alter flour, dough, and baking quality [
Contrasting results are reported about the relationships between water deficit and wheat quality. A spring water deficit could decrease N uptake and translocation to grains, thus reducing protein accumulation and grain quality [
Another very important aspect for both wheat and pasta quality is grain safety, with particular regards to mycotoxins, secondary metabolites produced by many genera of fungi. Mycotoxin presence depends on several factors, such as fungal strain, climatic and geographical conditions, and cultivation techniques [
Zearalenone and trichothecenes are produced by
Mycotoxins present in durum wheat grains and derived products are mainly due to infections by
In this work, the influence of cultivars and cropping system on agronomic, milling, technological, sensory, and sanitary quality of durum wheat and pasta has been evaluated within a local farm-to-table food chain.
The experiment was carried out from November 2009 to July 2010 in the Torre Lama experimental farm of the Naples University Federico II, located in an alluvial plain of Southern Italy (40°37′N, 14°58′E, 30 m a.s.l.). The soil was subalkaline (pH 7.5), silty-clay-loam (Clay 334 g kg−1, Silt 241 g kg−1, Sand 425 g kg−1) with low N and SOM content (1.2 g kg−1 and 18.4 g kg−1, resp.).
Five durum wheat cultivars (Matt, Karalis, Pablo, San Carlo, and Saragolla) were grown under conventional (mineral fertilization and chemical weed control) and organic (organic fertilization and no weed control) cropping systems in a farm scale experiment, arranging 1 ha plots in a complete randomized scheme with 2 replications. Therefore, the experiment was carried out on a 20 ha total area (5 cultivars × 2 cropping systems × 2 replications).
The preceding crop was corn in all the plots. Soil tillage was made on August 25, sowing on November 5, top dressing and chemical weed control (only on conventional plots) on March 22, and then harvest on June 29. The long time between soil tillage and sowing is usual in Mediterranean area where the main tillage (moldboard plowing) is done when the soil is well dry in all the 30–40 cm tillage layer (i.e., at the end of summer), while the seed-bed preparation (rotary hoeing) and sowing is made following the first autumn rainfalls (i.e., at November) when soil moisture become adequate for seed germination.
The N supply was calculated taking into account both uptake (27.2 kg N Mg−1 grain yield) and expected grain yield (4 Mg ha−1) suggested by the Regional Department of Agriculture. In order to improve grain quality and to reduce nitrate pollution, the soluble fertilizers were supplied after the rainy period, at the end of tillering.
In conventional cropping system, weed control was made with Atlantis WG (mefenpir-Dietile 90 g kg−1, Iodosulfuron-Metile-Sodio 6 g kg−1, Mesosulfuron-Metile 30 g kg−1, Bayer) mixed with Granstar 50 SX (Tribenuron metile 500 g kg−1, DuPont); fertilization was made with 88 kg ha−1 of Diammonium Phosphate (18.46.0) at sowing and 202 kg ha−1 of Urea (46.0.0) at the end of tillering (March 22).
In organic cropping system, chemical weed control was not made and fertilization was made at seeding with 1173 kg ha−1 of Naturale (8.8.6., Fertenia, Bellizzi, Italy), a fertilizer made with vegetable, meat and feather meal, and with 375 kg ha−1 of Borlanda (3.0.6, Fertenia, Bellizzi, Italy), a liquid fertilizer made from grape-vinasse, at the end of tillering (March 22).
During 2009-2010 (Figure
Average temperature (a), rainfalls (b), and water balance (c) during the growth period of wheat: 2009-2010 versus 1950–1980.
Measurements of yield components of wheat (total biomass weight, plant height, grain weight, harvest index, number of spikes per m2, number of grains per spike, grain average weight, % yellowberry, test weight) were made at harvest, on 3 sample areas (10 m2) per plot.
Quality analyses were carried out on grains, wholemeal, semolina, and pasta.
Test weight was determined on the grain samples by automatic instrument Infratec Grain Analyzer 1241 (FOSS AB Analytical, Sweden). The grains were milled to wholemeal with a Cyclotec mill-PBI (Italy) and sieved with a 1 mm mesh; the protein contents were determined by Dumas combustion method (ICC method n. 167) with automatic instrument Leco FP 428 (USA). Sedimentation index was evaluated in sodium-dodecyl-sulphate, according with the ICC method n. 151 with SDS 3%.
Semolina samples, obtained by a pilot milling plant (Buhler MLU 202) with three breaking and three sizing passages, were subjected to the following quality analyses: protein content, gluten quality, and color. Protein content was determined by Dumas combustion method, gluten content was determined according to EN ISO 21415 method. Gluten quality was evaluated by Gluten Index direct method by using Glutomatic System (Perten, Sweden) (ICC 158) and by an indirect method using the alveograph Chopin (UNI 10453 method). Semolina color, expressed by yellow and brown index, was evaluated by reflection colorimeter Minolta Chromameter CR-400 (illuminating D65) combined with CR-A50 for the measurements of granular material.
Semolina was also used to produce pasta samples (spaghetti shape, 1.65 mm diameter) by an experimental press (Namad, Italy) and by an experimental drying system (AFREM-France) employing a low-temperature drying diagram (50°C). Pasta cooking quality was assessed by sensory analysis both at the optimal cooking time (OCT) corresponding to the disappearance of starchy central core of spaghetti, and at a standard cooking time of 13 min (SCT) which corresponds to an overcooking for 1.65 mm diameter spaghetti. The sensorial judgment (SJ) is based on three textural characteristics: firmness, stickiness, and bulkiness [
Trichothecenes standards were purchased from Sigma-Aldrich (Milan, Italy) and stored at 4°C in the dark. Each standard was dissolved in methanol at 1 mg/mL concentration. Working solution and successive dilutions were prepared with solvent mixture (CH3OH/H2O, 70 : 30, v/v).
Water for LC mobile phase and organic solvents were HPLC grade from Merck (Darmstadt, Germany), ammonium acetate (MS grade) was purchased from Sigma-Aldrich, formic acid (p.a.) was obtained from Fluka (Milan, Italy). The extracts were filtered with Whatman no.4 type filter papers (Maidstone, England). Filtek syringe filters (0.22
Sample preparation and analysis were performed according to Santini and others [
LC analysis was performed using a system consisting of two micropumps (Series 200, PerkinElmer, Waltham, MA, USA). A Gemini column (3
Mobile phase A consisted of an H2O/CH3OH mixture (90 : 10, v/v) containing 5 mmol L−1 ammonium acetate, while mobile phase B consisted of a CH3OH/H2O mixture, also containing 5 mmol L−1 ammonium acetate (90 : 10, v/v). The following binary gradient was applied: initial condition 10% B; 0–7 min, 35% B; 7–9 min, 80% B; 9–13 min constant at 80% B; 13–15 min 100% B, finally returning to the initial conditions in 3 min.
MS/MS data were obtained using an API 3000 triple-quadrupole mass spectrometer (Applied Biosystems, Ont, Canada) equipped with an APCI interface, using the following settings: probe temperature 450°C, corona current (NC) ±2
The declustering potential (DP) and collision energy (CE) were optimized for each compound by direct infusion of standard solutions (10
The acquisition was performed in Multiple Reaction Monitoring (MRM) both in the negative and positive ion, depending on chemical structure of each compound.
In Table
LC/MS/MS characteristics of the analyzed compounds.
Analyte | Retention time (min) | Precursor ion | Product ions | DP | CE |
---|---|---|---|---|---|
NIV | 6.4 | 371.1 | 59 | 35 | 15 |
DON | 8.9 | 355.1 | 59 | 31 | 45 |
3-AcDON | 12.05 | 397.2 | 59 | 31 | 42 |
Fus X | 11.2 | 413.3 | 59 | 28 | 42 |
NEO | 11.4 | 400.1 | 305.1 | 40 | 17 |
HT-2 | 14.6 | 442.4 | 263 | 30 | 18 |
T-2 | 15.9 | 484.2 | 305.2 | 35 | 20 |
DAS | 13.4 | 384.2 | 307.2 | 40 | 17 |
A two factor completely randomized design with two replications was used to assess the effects of cultivars and cropping systems. Analysis of variance (ANOVA) was performed by the MSTAT-C software (Crop and Soil Science Department, Michigan State University, Version 2.0). Means of the factors that resulted significant from ANOVA (
The interaction between cropping systems and cultivars was not significant for grain yield (Table
Grain yield: effect of cropping system and cultivar.
Cropping system cultivar | Organic | Conventional | Average | Difference in organic |
Mg ha−1 | Mg ha−1 | Mg ha−1 | % | |
Matt | 2.13 | 2.85 | 2.48 b | −25.0 |
Saragolla | 3.62 | 4.09 | 3.85 a | −11.4 |
Karalis | 2.33 | 3.22 | 2.78 b | −27.6 |
Pablo | 2.57 | 2.99 | 2.78 b | −14.2 |
San Carlo | 2.46 | 3.45 | 2.94 b | −28.8 |
Average | 2.52 b | 3.23 a | 2.87 | −21.0 |
Different letters indicate significant differences per
Yield components: effect of cropping system and cultivar.
Biomass Yield | Plant Height | Harvest Index | Spikes | Average weight | Yellowberry | Hectoliter weight | ||
Mg ha−1 | cm | % | Num·m−2 | g spike−1 | mg grain−1 | % | g Hl−1 | |
Cultivar | ||||||||
Matt | 10.8 b | 63 a | 24.0 b | 573 a | 0.76 c | 43.1 b | 21.5 | 84 a |
Saragolla | 11.9 ab | 67 a | 32.1 a | 334 c | 1.41 a | 48.5 b | 14.8 | 82 b |
Karalis | 14.2 a | 52 b | 20.6 b | 341 c | 1.10 b | 57.6 a | 22.9 | 85 a |
Pablo | 12.6 ab | 51 b | 22.5 b | 491 ab | 0.58 c | 48.4 b | 26.0 | 79 c |
San Carlo | 10.1 b | 56 ab | 29.1 a | 448 abc | 1.00 b | 49.5 b | 30.5 | 81 bc |
Cropping system | ||||||||
Organic | 12.3 | 61.5 a | 23.5 b | 415 | 0.96 | 48.8 | 35.6 a | 82 |
Conventional | 11.6 | 54.4 b | 27.9 a | 461 | 0.98 | 50.2 | 10.6 b | 83 |
Different letters indicate significant differences per
Wheat yield (Table
The highest yield was obtained by Saragolla (3.8 Mg ha−1), while the values were significantly lower for the other cultivars (2.5–2.9 Mg ha−1).
Though the interaction cropping system by cultivar was not significant according with ANOVA, a different behavior of the cultivar is identifiable with lower yield losses under the organic system, as compared to the conventional one, for Saragolla and Pablo (−11 and −14% resp.). This suggests that those two cultivars may be more suitable to organic farming and confirms the importance of genotype selection for adaptability to organic farming [
Total biomass yield (Table
The number of spikes per m2 was very high on the average, particularly for the cultivars Matt, Pablo, and San Carlo, while the average weight of spikes was very low mainly for Matt and Pablo. The average weight of kernels was low on the average, with the exception of Karalis. The effect of cropping system on these parameters was not significant.
The percentage of yellowberry was not different among the cultivars, while it was significantly higher under organic conditions systems (35.6% versus 10.6% on the average).
The hectoliter weight was higher in Karalis and Matt and lower in Pablo, while it was not related to the kind of fertilization. In any case it was higher than 80 that is considered the minimum threshold by the major pasta factories.
The results of quality assessment (Table
Quality parameters of wholemeal and semolina of durum wheat varieties cultivated with conventional and organic cropping systems.
Cultivar | Wholemeal | Semolina | |||||||
Protein | SDS | Protein | Gluten | Gluten Index | W | P/L | Yellow index | Brown index | |
Conventional cropping system | |||||||||
Karalis | 146 | 57 | 133 | 111 | 84 | 217 | 0.85 | 18.8 | 10.0 |
Matt | 163 | 64 | 140 | 118 | 75 | 232 | 0.81 | 26.3 | 10.5 |
Pablo | 122 | 60 | 115 | 96 | 88 | 216 | 0.81 | 28.5 | 10.6 |
San Carlo | 119 | 50 | 103 | 84 | 95 | 180 | 2.10 | 24.0 | 10.1 |
Saragolla | 133 | 49 | 126 | 93 | 86 | 191 | 1.37 | 25.2 | 12.3 |
Organic cropping system | |||||||||
Karalis | 101 | 42 | 95 | 75 | 95 | 145 | 1.23 | 17.0 | 8.1 |
Matt | 104 | 41 | 97 | 77 | 89 | 156 | 1.18 | 22.3 | 8.3 |
Pablo | 115 | 46 | 105 | 90 | 83 | 183 | 1.13 | 27.2 | 10.5 |
San Carlo | 115 | 51 | 103 | 85 | 93 | 178 | 2.20 | 22.8 | 10.1 |
Saragolla | 120 | 42 | 108 | 81 | 94 | 159 | 1.71 | 23.5 | 10.2 |
Variation (%) with organic cropping system | |||||||||
Karalis | −30.3 | −26.3 | −28.7 | −32.7 | 13.1 | −33.2 | 44.7 | −9.6 | −18.3 |
Matt | −36.5 | −35.9 | −30.5 | −34.8 | 18.7 | −32.8 | 45.7 | −15.2 | −21.0 |
Pablo | −6.0 | −23.3 | −8.6 | −7.2 | −5.7 | −15.3 | 39.5 | −4.7 | −1.1 |
San Carlo | −3.5 | 2.0 | 0.5 | 0.6 | −2.1 | −1.1 | 4.8 | −5.0 | 0.5 |
Saragolla | −10.3 | −14.3 | −14.8 | −13.2 | 9.3 | −16.8 | 24.8 | −6.6 | −17.2 |
− | − | − | − | − | − | − |
S.D.: Standard deviation.
The results obtained from pasta cooking evaluation (Table
Cooking quality parameters of pasta from durum wheat varieties cultivated with conventional and organic cropping systems.
Cultivar | Optimal cooking time (OCT) | Standard Cooking time (SCT = 13 min) | |||||||
Time | Firmness | Stickiness | Bulkiness | Final judgment | Firmness | Stickiness | Bulkiness | Total judgment | |
Conventional cropping system | |||||||||
Karalis | 9′20′′ | 57 | 80 | 57 | 20 | 73 | 43 | ||
Matt | 9′45′′ | 57 | 85 | 60 | 50 | 72 | 55 | ||
Pablo | 10′15′′ | 55 | 78 | 55 | 25 | 68 | 45 | ||
San Carlo | 9′30′′ | 45 | 75 | 52 | 38 | 68 | 47 | ||
Saragolla | 9′05′′ | 72 | 80 | 65 | 42 | 63 | 50 | ||
Organic cropping system | |||||||||
Karalis | 9′40′′ | 42 | 72 | 45 | 10 | 57 | 35 | ||
Matt | 9′20′′ | 48 | 70 | 50 | 18 | 65 | 43 | ||
Pablo | 9′35′′ | 40 | 73 | 45 | 32 | 65 | 45 | ||
San Carlo | 9′50′′ | 55 | 73 | 53 | 23 | 72 | 45 | ||
Saragolla | 9′45′′ | 50 | 75 | 57 | 33 | 73 | 45 | ||
Variation (%) with organic cropping system | |||||||||
Karalis | 4 | −26 | −10 | −21 | −50 | −22 | −19 | ||
Matt | −4 | −16 | −18 | −17 | −64 | −10 | −22 | ||
Pablo | −7 | −27 | −6 | −18 | 28 | −4 | 0 | ||
San Carlo | 4 | 22 | −3 | 2 | −39 | 6 | 6 | ||
Saragolla | 7 | −31 | −6 | −12 | −21 | 16 | 6 | ||
1 | −18 | −9 | −13 | −34 | −3 | −6 | |||
6 | 22 | 6 | 9 | 36 | 15 | 14 |
S.D.: Standard deviation.
Resistance to overcooking expressed as the difference between SCT and OCT.
Cultivar | Firmness | Stickiness | Bulkiness | Total judgment |
---|---|---|---|---|
Conventional cropping system | ||||
Karalis | −37 | −7 | −14 | |
Matt | −7 | −13 | −5 | |
Pablo | −30 | −10 | −10 | |
San Carlo | −7 | −7 | −5 | |
Saragolla | −30 | −17 | −15 | |
− | − | − | ||
Organic cropping system | ||||
Karalis | −32 | −15 | −10 | |
Matt | −30 | −5 | −7 | |
Pablo | −8 | −8 | 0 | |
San Carlo | −32 | −1 | −8 | |
Saragolla | −17 | −2 | −12 | |
− | − | − | − | |
S.D.: Standard deviation.
The comparison between the two cropping systems showed that the organic system determined a reduction of protein content, gluten content, and quality as evidenced by protein level and SDS test in wholemeal and by protein content, gluten content, and alveographic W values in semolina, thus confirming the well-known effects of N nutrition on the quality parameters [
Pasta cooking quality with organic system reached lower scores in comparison with conventional system. In OCT experimental conditions, the reduction of pasta quality from organic wheat was similar among the cultivars (from −16 to −18), except for San Carlo that showed a little increase in the pasta quality score (+5). On the contrary, when SCT was used (i.e., in overcooking conditions), the quality decrease was very high for Karalis and Matt (−15 and −29 resp.), while Pablo, San Carlo, and Saragolla were somewhat unaffected by the cropping systems. These differences were already expected considering the different varietal responses to the lower levels of protein content and gluten quality, that are widely recognized as the most important parameters for pasta processing, mainly when low temperature drying cycles were used [
Comparison between productive and qualitative parameters showed a positive correlation between grain yield and pasta quality (
As expected [
The average level of Nivalenol was about 20
On the contrary high Nivalenol contamination in wheat grain occurred in more rainy areas: Ioos and others [
Deoxynivalenol concentration averaged 70.8
A study conducted in Italy, showed a decreasing deoxynivalenol contamination from Northern to Southern regions [
On the contrary, in Northern Italy the deoxynivalenol content during the rainier year was higher than the admissible maximum levels (1750 mg kg−1) based on UE Commission Regulation (EC) 1881/2006 of December 19, 2006 [
Fusarenon X, neosalaniol,T-2 toxin, HT-2 toxin, diacetoxyscirpenol, and 3-acetyldeoxynivalenol in analyzed samples were below the detection limit.
Literature data report that the main producers of T-2, HT-2 and neosolaniol (
The data about mycotoxins contamination obtained in this experiment clearly show that durum wheat cultivated in the climatic conditions of Southern Italy is safer than in Northern Italy or Central Europe, confirming the results of other studies [
The production of durum wheat for high-quality pasta in Southern Italy was mainly affected by the different responses of cultivars to the lower N availability caused by organic cropping system.
Higher N availability during the spring, belonging to mineral fertilization at the end of tillering (March), allowed Matt to produce the best quality pasta, while its performance was unsatisfactory under organic farming conditions.
Saragolla showed the highest yield and a high pasta quality in all the experimental conditions, thus proving to be a cultivar very adaptable to the lower N availability occurred under organic farming.
In conventional cropping systems, fractional application of N fertilizer is mandatory to gain the best results in terms of pasta quality, concentrating the highest dose at the end of rainy season (March, in Mediterranean environments). The scheme used in this experiment (25% of the total N uptake at sowing and 75% at the end of tillering) resulted appropriate to this aim.
In particularly rainy years, an increase of the N spring dose may be necessary. On the contrary, in drier seasons, irrigation (about 30 mm) at the end of stem elongation-boot stage could help the N uptake by plant. In this experiment, this was not necessary, since the rainfalls in May-June (141 mm) were able to allow a regular N uptake.
In organic cropping systems, the supply of a soluble fertilizer (vinasse) at the end of tillering was not sufficient to allow the adequate N availability for all the cultivars. In this case only, the choice of an adaptable genotype, such as Saragolla, can allow gaining satisfactory results in terms of yield amount and pasta quality. Nevertheless, only the presence of legume crops in long-term crop rotations could guarantee the necessary N availability at sustainable costs.
In these experimental conditions, very low levels of nivalenol (NIV) and deoxynivalenol (DON) were measured in wheat grains, with values much lower than the thresholds of European legislation (1750
These results confirmed the importance of the environmental conditions on mycotoxin contamination of durum wheat, that is, a problem only in more humid areas (such as Northern Italy and Central Europe), while in Southern Italy, durum wheat grains are generally free from this kind of contamination, also in a year that was more rainy than the long-term average values, such as that of this experiment. The production from organic cropping system was also mycotoxin free.
All the data collected in this experiment show that the environmental conditions of Southern Italy allow to produce durum wheat and pasta of high quality both in terms of safety and organoleptic characteristics.
These results support the creation of a short food chain (so called “km zero”) that minimizes the environmental impact of all the production phases by reducing emissions related to the transport.
The authors wish to thank Pastificio Garofalo for its financial support to this research and Professor Roberto Vona, President of the Azienda Agraria Torre Lama of the Naples University Federico II, for making possible its realization. The authors do not have any financial relations with the commercial identities mentioned in the text, and, therefore, there is no conflict of interests for any of them.