Discrimination of the Sicilian Prickly Pear (Opuntia Ficus-Indica L., CV. Muscaredda) According to the Provenance by Testing Unsupervised and Supervised Chemometrics.

Different multivariate techniques were tested in an attempt to build up a statistical model for predicting the origin of prickly pears (Opuntia ficus-indica L., cv. Muscaredda) from several localities within the Sicilian region. Specifically, two areas known for producing fruits marked respectively by TAP (traditional agri-food product) and PDO (protected designation of origin) brands, and three sites producing non-branded fruits, were considered. A validated inductively coupled plasma mass spectrometry (ICP-MS) method allowed to obtain elemental fingerprints of prickly pears, which were subsequently elaborated by unsupervised tools, such as hierarchical clustering analysis (HCA) and principal component analysis (PCA), and supervised techniques, such as stepwise-canonical discriminant analysis (CDA) and partial least squares-discriminant analysis (PLS-DA). With the exception of HCA, which was not enough powerful to correctly cluster all selected samples, PCA successfully investigated the effect of subregional provenance on prickly pears, thus, differentiating labeled products from the non-labeled counterpart. Also, stepwise CDA and PLS-DA allowed to build up reliable models able to correctly classify 100% of fruits on the basis of the production areas, by exploiting a restricted pool of metals. Both statistical models, including unsupervised (PCA) and supervised techniques (stepwise CDA or PLS-DA), may guarantee the provenance of prickly pears protected by quality labels and safeguard producers and consumers. PRACTICAL APPLICATION: Based on elemental analysis and chemometrics, the reliable traceability models herein proposed, could be applied to commercial Sicilian prickly pears protected by TAP and PDO logos to guarantee their provenance and, at the same time, to safeguard producers and consumers.

Removal of heavy metal ions from wastewaters using dendrimer-functionalized multi-walled carbon nanotubes.

Dendrimer-functionalized multi-walled carbon nanotubes (MWCNT) for heavy metal ion removal from wastewaters were developed. Triazole dendrimers (TD) were built directly onto the carbon nanotube surface by successive click chemistry reactions affording the zero- and first-generation dendrimer-functionalized MWCNT (MWCNT-TD1 and MWCNT-TD2). The Moedritzer-Irani reaction carried out on the amino groups present on the MWCNT-TD2 sample gave the corresponding α-aminophosphonate nanosystem MWCNT-TD2P. Both MWCNT-TD2 and MWCNT-TD2P nanosystems have been characterized by physical, chemical, and morphological analyses. Their chelating abilities towards the toxic metal ions Pb2+, Hg2+, and Ni2+ and the harmless Ca2+ ion have been experimentally evaluated in the two different sets of experiments and at the salt concentrations of 1 mg/mL or 1 µg/mL by inductively coupled plasma mass spectrometry (ICP-MS). The results of these studies pointed out the interesting chelating behavior for the phosphonated nanosystem towards the Hg2+ ion. The complexation mode of the best chelating system MWCNT-TD2P with mercury was investigated through density functional theory (DFT) calculations, suggesting a chelation mechanism involving the two oxygen atoms of the phosphate group. The synthesized dendrimers, supported on the multi-walled carbon nanotubes, have shown the potential to be used for the selective toxic metal ion removal and recovery.

Release of nickel and chromium in common foods during cooking in 18/10 (grade 316) stainless steel pots.

BACKGROUND: Literature data on the release of nickel and chromium from stainless steel cookware during food preparation are contrasting, have often been obtained with uncommon foods and/or procedures, and are thus not widely applicable. OBJECTIVES: To assess the release of nickel and chromium from 18/10 (grade 316) stainless steel pots in cooking conditions that are common in an urban lifestyle. METHODS: Tomato sauce and lemon marmalade were cooked for 1 h, alone or with added EDTA, in used or unused stainless steel pots from different manufacturers. Additionally, aqueous solutions at pH 2.3, 7.7 and 9 were boiled for 1 h in the same pots. Metal release was assessed with inductively coupled plasma mass spectrometry. RESULTS: The release of nickel and chromium increased with cooking/boiling time, was higher with unused pots, at low pH or with EDTA, and was sometimes remarkably different between manufacturers. In all experiments, the amounts released were below known allergy-triggering thresholds. CONCLUSIONS: Under common conditions, the use of 18/10 stainless steel pots is considered to be safe for the majority of nickel-allergic and/or chromium-allergic subjects. However, the total amount of nickel contained in foods and released from pots may exceed the individual threshold for triggering allergy, potentially causing problems for highly sensitive patients, or, conversely, contribute to induction of immunotolerance by oral low-dose exposure.

Statistical Analysis of Mineral Concentration for the Geographic Identification of Garlic Samples from Sicily (Italy), Tunisia and Spain.

We performed a statistical analysis of the concentration of mineral elements, by means of inductively coupled plasma mass spectrometry (ICP-MS), in different varieties of garlic from Spain, Tunisia, and Italy. Nubia Red Garlic (Sicily) is one of the most known Italian varieties that belongs to traditional Italian food products (P.A.T.) of the Ministry of Agriculture, Food, and Forestry. The obtained results suggest that the concentrations of the considered elements may serve as geographical indicators for the discrimination of the origin of the different samples. In particular, we found a relatively high content of Selenium in the garlic variety known as Nubia red garlic, and, indeed, it could be used as an anticarcinogenic agent.