Multiresidual LC-MS analysis of plasticizers used in PVC gaskets of lids and assessment of their migration into food sauces.

Plasticizers may migrate from polyvinyl chloride (PVC) gaskets into the foodstuffs mainly by direct contact during the packaging and sterilization procedure, but also by means of occasional contacts occurring during shipment and storage. The present work reports a reliable liquid chromatography-mass spectrometry (LC-MS) method able to quantify the main plasticizers used in the PVC closure gaskets for metal lids to verify their compliance in both food contact materials and foodstuffs. The atmospheric pressure chemical ionization in the positive ion mode resulted the best performing interface for the multiresidual detection of the plasticizers taken into account, followed by selected/multiple reaction monitoring, selected ion monitoring or full scan experiments, depending on the compounds to detect. The method was single-laboratory validated, demonstrating to reach a good sensitivity, thus making possible to perform analysis without any preliminary sample purification or concentration step. It proved to be effectively applicable not only for the determination of plasticizers in PVC gaskets but also in complex food matrices. In particular, it was applied for monitoring plasticizer migration into sauces placed in contact with the lids in worst storage conditions, observing therefore their trend during the shelf-life. Copyright © 2016 John Wiley & Sons, Ltd.

Biocatalytic conversion of poultry processing leftovers: Optimization of hydrolytic conditions and peptide hydrolysate characterization.

Peptide hydrolysate (PH) was produced by deep controllable bioconversion of poultry processing leftovers (broiler necks), by means of a multienzyme composition, containing four commercially available enzyme preparations (Alcalase, Neutrase, Flavourzyme, Protamex). The design of multienzyme composition (MEC) was applied to yield a hydrolysate with adjusted properties, including minimized antigenicity and bitterness. The protein recovery was optimized using Box-Behnken response surface design. The individual and interactive effects of hydrolysis conditions (time, hydromodule and MEC dosage) were studied. The experimental data were analyzed by ANOVA method and a well-predictive, second order polynomial model was developed using multiple regression analysis. Optimal hydrolysis conditions were found to be: hydrolysis time 3 h, hydromodule 2.25 l/kg and dosage of MEC 0.25%. The corresponding predicted value for protein recovery was 75.34%, 2 times higher compared to traditional long-term heating hydrolysis. The PH obtained is a low allergenic product with high antioxidant capacity.

Cheese peptidomics: a detailed study on the evolution of the oligopeptide fraction in Parmigiano-Reggiano cheese from curd to 24 months of aging.

In this work, we performed a detailed evaluation of the evolution of the oligopeptide fractions in samples of Parmigiano-Reggiano cheese from the curd up to 24 mo of aging. The samples were taken from wheels produced the same day, in the same factory, from the same milk, during the same caseification process, thus simplifying the natural variability of a whey-based starter fermentation. This unique and homogeneous sampling plan, never reported before in the literature, provided a detailed study of the peptides produced by enzymatic events during Parmigiano-Reggiano aging. Given the large dimensions of the 35-kg wheels of Parmigiano-Reggiano, samples were taken from both the internal and external parts of the cheese, to evidence eventual differences in the oligopeptide composition of the different parts. Fifty-seven peptides were considered, being among the most abundant during at least one of the periods of ripening considered, and their semiquantification indicated that the peptide fraction of Parmigiano-Reggiano cheese constantly evolves during the aging period. Five trends in its evolution were outlined, which could be clearly correlated to the enzymatic activities present in the cheese, making it possible to discriminate cheeses according to their aging time. Several known bioactive peptides were also found to be present in Parmigiano-Reggiano cheese samples, and for the first time, the age at which they are most abundant has been identified. Aged cheeses have been shown to be dominated by nonproteolytic aminoacyl derivatives, a new class of peptide-like molecules recently reported. Finally, the changing peptide pattern may be related to the changing enzymatic activities occurring inside the cheeses during the aging period, which, in turn, are also related to the microbiological composition.

[The effect of phenobarbital on anti-mitotic activity of vincristine and colchicine. Experimental study]. / Effetto del fenobarbital sulla attività antimitotica della vincristina e della colchicina.

The effect of phenobarbital on vincristine and colchicine antimitotic activity has been studied. The number of mitotic figures present in the rat bone marrow and Galeazzi-Lieberkühn cripts has been used to evaluate the overall proliferative activity of these cell populations. The administration of phenobarbital brought a reduction in the percentage of arrested mitoses in rat bone marrow and intestinal glands after treatment with vincristine and colchicine. Parallel studies on the phenobarbital effect on the LD50 and LD100 of vincristine and colchicine confirmed a decreased toxicity of these agents in the animals pretreated with phenobarbital.

Changes in the small biliary passages in the hepatic localization of Hodgkin's disease.

The authors have investigated the behaviour of the small biliary passages in the liver biopsies of six patients suffering from untreated Hodgkin's disease with hepatic localization. No obstruction of the major bile ducts was demonstrated in any patient. Three of the patients were anicteric, while the three others presented with jaundice. In the first three cases typical Hodgkin's granulation tissue appears to be limited to portal tracts and collagen reaction is virtually absent. The three cases with cholestasis showed granulomatous tissue associated with heavy connective tissue rearrangement invading and dissociating the lobular structure. They also show a conspicuous bile-duct proliferation, which is not observed in the three anicteric patients. In these latter cases, however, the small bile ducts running within or near the granulomatous tissue present various morphologic changes, including basal membrane thickening, dilation or constriction of the lumen and alterations of the biliary epithelial lining. Complete disappearance of the bile duct may occur.

Stereometry of the red pulp on the human spleen. I) Methodological remarks.

The principal histometrical formulas to be applied to the analysis of human spleen's red pulp are illustrated. The discussion particularly concerns the formulas to evaluate the following measures per unit splenic volume:volume of the elements; surface area of sinus-splenic cord boundaries; mean breadth of cords; length of the sinus; mean sectional area of the sinus. Suggestions are given about the criteria to be followed in the proper assumption of the data which must be subjected to statistical estimation.

Stereometry of the red pulp on the human spleen. II) The normal spleen.

The stereometric measurements obtained in three human normal spleens surgically removed for trauma have been submitted to statistical evaluation. On the basis of the original counts, some stereometric measures of the normal splenic red pulp have been determined, namely per cent volume of sinuses, per cent volume of cords, breadth of the cords, mean sectional area of sinuses and the volume of sinuses:volume of cords ratio. These data can constitute a series of parameters to which compare the measures of the pathologic spleens.