Simonetta Menotta

Separation and analysis of phospholipids in different foods with a light-scattering detector

A method for the separation of phospholipids (PL) from total lipids by solid-phase extraction (SPE) with reversephase C8 cartridges is described. The method was validated with a standard mixture of PL and applied to natural food matrixes, such as egg, chicken meat, salami, and ripened cheese. The recovery of PL ranged between 93 and 99.7% and was evaluated by an organic phosphorus spectrophotometric determination. The egg powder PL fraction obtained by SPE contained about 20% (w/w) nonpolar PL material when 100–150 mg of lipids were loaded onto the cartridge. Higher percentages of nonphospholipid components (30–43%) were obtained when the amount of lipids loaded was below or above the 100–150 mg range. The purified PL fractions were analyzed by high-performance liquid chromatography (HPLC) with an evaporative light-scattering detector. Good HPLC performance was observed even with low-purity SPE fractions (43% nonphospholipid material).

High-performance liquid chromatography separation and light-scattering detection of phospholipids from cooked beef

A sensitive high-performance liquid chromatography (HPLC) method for the separation and quantitative analysis of major phospholipids (PLs) in biological systems is described. PLs were purified by solid-phase extraction with an amino (NH2) phase. Separation of PLs was carried out on an HPLC silica gel column, with a mobile phase consisting of chloroform, methanol and ammonium hydroxide, and detection was performed with a light-scattering evaporative detector. HPLC analysis of PLs extracted from ground beef cooked under different conditions and capillary gas chromatography of the fatty acid methyl esters showed that cooking treatments did not have a significant effect on the PL composition and fatty acid contents of the single PLs in ground beef.

Survey on Urinary Levels of Aflatoxins in Professionally Exposed Workers

Feed mill workers may handle or process maize contaminated with aflatoxins (AFs). This condition may lead to an unacceptable intake of toxins deriving from occupational exposure. This study assessed the serological and urinary levels of AFs in workers exposed to potentially contaminated dusts in two mills. From March to April 2014, blood and urine samples were collected, on Monday and Friday morning of the same working week from 29 exposed workers and 30 non-exposed controls. AFs (M1, G2, G1, B1, B2) and aflatoxicol (AFOH) A were analyzed. Each subject filled in a questionnaire to evaluate potential food-borne exposures to mycotoxins. AFs contamination in environmental dust was measured in both plants. No serum sample was found to be positive. Seventy four percent of urine samples (73.7%) revealed AFM1 presence. AFM1 mean concentration was 0.035 and 0.027 ng/mL in exposed and non-exposed workers, respectively (p = 0.432); the concentration was slightly higher in Friday’s than in Monday’s samples, in exposed workers, 0.040 versus (vs.) 0.031 and non-exposed controls (0.030 vs. 0.024, p = 0.437). Environmental AFs contamination ranged from 7.2 to 125.4 µg/kg. The findings of this study reveal the presence of higher AFs concentration in exposed workers than in non-exposed controls, although these differences are to be considered consistent with random fluctuations.

Intake estimates of dioxins and dioxin-like polychlorobiphenyls in the Italian general population from the 2013-2016 results of official monitoring plans in food

The implementation of the European Union strategy for polychlorodibenzo-dioxins and -furans (PCDD/Fs), and dioxin-like polychlorobiphenyls (DL-PCBs) is determining a general reduction of their presence in the environment and in the food chain. The most important route for human exposure to these substances is food consumption and, as a consequence, a progressive decrease of their dietary intake has been observed in the last decades. In this context, it seemed worth updating the PCDD/F and DL-PCB intake estimation for the Italian population. A total of 2659 samples of food of animal and vegetable origin analyzed for PCDD/Fs and DL-PCBs in the period 2013-2016 by accredited official laboratories and the national food consumption database were considered for the dietary intake assessment in different age groups of the Italian general population The median cumulative intake estimates expressed as pg WHO-TEQ/kg body weight per day and computed with a deterministic and a probabilistic approach were 1.40-1.52 for children, 0.82-0.85 for adolescents, and 0.64-0.61 for adults, respectively. Such results confirm the decreasing trend of PCDD/F and DL-PCB dietary intake even though the Tolerable Daily Intake (TDI) value of 2 WHO-TEQ/kg body weight per day is exceeded at the 95th percentile for all age groups, with children as sensitive group. Most contributing food categories to the intake resulted fish, food of vegetable origin, and cheese. A sensitivity analysis was also performed to calculate the target contamination levels able to keep the dietary exposure below the TDI. Computed target levels fall between P50 and P97 of the occurrence distribution of the main food groups, meaning that most of the Italian food production can be considered safe.

Checking syrup adulteration of honey using bioluminescent bacteria and chemometrics

Accomplishing the Italian law to verify honey quality is onerous, because it requires measuring many chemical and physical parameters. On the contrary, bioluminescence-based analytical methods allow for rapid and inexpensive analysis. Bioluminescence has never been applied before to verify honey adulteration. The application of chemometrics to analytical methods based on bioluminescence has been here explored for this scope. Several honey samples were prepared, in which sugar syrup was added without exceeding legal limits: in this case, univariate analysis prescribed by the law cannot reveal the fraud. All samples were subjected to measurements of parameters prescribed by the law and also to bioluminescence analysis, executed using the Vibrio fischeri bacterium, one of the most common bioluminescent bacteria. Principal components analysis, linear discriminant analysis, and partial least square regression were applied to discriminate sugar-added honeys with respect to natural honeys, both by regulated physicochemical parameters and by bioluminescence ones. The feasibility of combining bioluminescence and multivariate analysis for a rapid screening of honey authenticity was demonstrated.