Use of Air-Classification Technology to Manage Mycotoxin and Arsenic Contaminations in Durum Wheat-Derived Products.

Mycotoxins are the most common natural contaminants and include different types of organic compounds, such as deoxynivalenol (DON) and T-2 and HT-2 toxins. The major toxic inorganic elements include those commonly known as heavy metals, such as cadmium, nickel, and lead, and other minerals such as arsenic. In this study, micronisation and air classification technologies were applied to durum wheat (Triticum turgidum ssp. durum L.) samples to mitigate inorganic (arsenic) and organic contaminants in unrefined milling fractions and final products (pasta). The results showed the suitability of milling plants, providing less refined milling products for lowering amounts of mycotoxins (DON and the sum of T-2 and HT-2 toxins) and toxic inorganic elements (As, Cd, Ni, and Pb). The results showed an As content (in end products) similar to that obtained using semolina as raw material. In samples showing high organic contamination, the contamination rate detected in the more bran-enriched fractions ranged from 74% to 150% (DON) and from 119% to 151% (sum of T2 and HT-2 toxins) as compared to the micronised samples. Therefore, this technology may be useful for manufacturing unrefined products with reduced levels of organic and inorganic contaminants, minimising the health risk to consumers.

Hydrothermal grain pre-processing and ultra-fine milling for the production of durum wheat flour fractions with high nutritional value.

This work describes a process for producing durum wheat flour fractions with high potential nutritional value using grain pre-milling hydrothermal treatment and ultra-fine grinding (micronization), coupled with air classification. The difference of bioactive value of the flour fractions in relation to dietary fibre and phenolic compounds was monitored on four durum wheat cultivars by analysing total arabinoxylans, water extractable arabinoxylans and 5- n-alkylresorcinols. The extractability of the analysed compounds was most significantly affected by hydrothermal treatment. On average, the hydrothermally treated kernels compared with the untreated ones presented a marked increase of water extractable arabinoxylans and alkylresorcinols (about 25 and 48%, respectively), whereas slightly lower total arabinoxylans content (about 9%) was detected. The air classification applied on micronized kernels produced two flour fractions, coarse and fine, with the last showing, irrespective of the hydrothermal treatment, an increment of alkylresorcinols (24 and 22% in untreated and treated samples) and of total arabinoxylans (13 and 20% in untreated and treated samples) in comparison with the coarse one. The fine fraction (particles ≤ 120 µm), resulting richer in bioactive compounds, provides an interesting raw material to enrich traditional semolina in which, due to the removal of the external layers, the losses of total arabinoxylans and of alkylresorcinols were more than 60 and 90% alkylresorcinols, respectively, if compared with whole wheat grain.

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 ß-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.