Oxytetracycline residues from spiked ovine milk to cheese: technological implications

Antibiotics are used in livestock, in order to ensure the health of producing-food animals. Their wide use can cause an undesirable presence of residues in milk and milk products, representing a risk for human health. To guarantee the safety of consumers, the Commission Regulation (EU) 37/2010 states the Maximum Residue Limit (MRL) of pharmacologically active substances in foodstuffs of animal origin, included milk, but no limits are specified for cheese. In addition, residues in milk can have negative technological effects during the manufacturing of dairy products. Oxytetracycline (OTC) is one of the most used veterinary antibiotics in Sardinia, due to its effectiveness and low cost. The aim of this PhD thesis was to study the distribution, between cheese and whey, of OTC added in ovine milk at MRL level, and to verify technological effects during the cheese-making process. The first part of thesis was a preliminary investigation conducted by lab cheese-making method. In the second part were conducted experimental cheese-makings from whole raw milk spiked at MRL level, to understand the partition of molecule and to evaluate technological effects during the manufacturing and ripening. In the third and fourth parts were performed experimental cheese-makings from whole thermised milk spiked at half and MRL levels, to assess the influence of the thermisation on the recovery and partition of OTC, and to understand the effect of residues on the starter culture development

Graphene as cancer theranostic tool: progress and future challenges.

Nowadays cancer remains one of the main causes of death in the world. Current diagnostic techniques need to be improved to provide earlier diagnosis and treatment. Traditional therapy approaches to cancer are limited by lack of specificity and systemic toxicity. In this scenario nanomaterials could be good allies to give more specific cancer treatment effectively reducing undesired side effects and giving at the same time accurate diagnosis and successful therapy. In this context, thanks to its unique physical and chemical properties, graphene, graphene oxide (GO) and reduced graphene (rGO) have recently attracted tremendous interest in biomedicine including cancer therapy. Herein we analyzed all studies presented in literature related to cancer fight using graphene and graphene-based conjugates. In this context, we aimed at the full picture of the state of the art providing new inputs for future strategies in the cancer theranostic by using of graphene. We found an impressive increasing interest in the material for cancer therapy and/or diagnosis. The majority of the works (73%) have been carried out on drug and gene delivery applications, following by photothermal therapy (32%), imaging (31%) and photodynamic therapy (10%). A 27% of the studies focused on theranostic applications. Part of the works here discussed contribute to the growth of the theranostic field covering the use of imaging (i.e. ultrasonography, positron electron tomography, and fluorescent imaging) combined to one or more therapeutic modalities. We found that the use of graphene in cancer theranostics is still in an early but rapidly growing stage of investigation. Any technology based on nanomaterials can significantly enhance their possibility to became the real revolution in medicine if combines diagnosis and therapy at the same time. We performed a comprehensive summary of the latest progress of graphene cancer fight and highlighted the future challenges and the innovative possible theranostic applications.journal articleresearch support, non-u.s. gov'treview20152015 03 28importe

Exploring the DPP-IV Inhibitory, Antioxidant and Antibacterial Potential of Ovine “Scotta” Hydrolysates

The aim of this work was to valorize the by-product derived from the ricotta cheese process (scotta). In this study, ovine scotta was concentrated by ultrafiltration and then subjected to enzymatic hydrolyses using proteases of both vegetable (4% E:S, 4 h, 50 °C) and animal origin (4% E:S, 4 h, 40 °C). The DPP-IV inhibitory, antioxidant, and antibacterial activities of hydrolysates from bromelain (BSPH) and pancreatin (PSPH) were measured in vitro. Both the obtained hydrolysates showed a significantly higher DPP-IV inhibitory activity compared to the control. In particular, BSPH proved to be more effective than PSPH (IC50 8.5 ± 0.2 vs. 13 ± 1 mg mL−1). Moreover, BSPH showed the best antioxidant power, while PSPH was more able to produce low-MW peptides. BSPH and PSPH hydrolysates showed a variable but slightly inhibitory effect depending on the species or strain of bacteria tested. BSPH and PSPH samples were separated by gel permeation chromatography (GPC). LC-MS/MS analysis of selected GPC fractions allowed identification of differential peptides. Among the peptides 388 were more abundant in BSPH than in the CTRL groups, 667 were more abundant in the PSPH group compared to CTRL, and 97 and 75 of them contained sequences with a reported biological activity, respectively

Transfer of antibiotics from goat's milk to rennet curd and whey fractions during cheese-making

[EN] The transfer of 35 antibiotics from milk to curd and whey was evaluated. Cheeses were produced at laboratory scale, from antibiotic-free goat's milk spiked with different antibiotic concentrations between 0.25 and 4 times the Maximum Residue Limits established in milk. Drug concentrations in milk, curd and whey were analysed by UHPLC-HRMS. Results indicated that most antibiotics were mainly transferred from milk to whey (up to 85.9%), with retention percentages in the curd lower than 50%, except for ceftiofur (59.7%) and dicloxacillin (52.8%). In most cases, drug distribution was unaffected by the antibiotic concentration in milk and correlated significantly to the drug lipophilicity (Log P) for beta-lactams (R-2 = 0.54) and sulfonamides (R-2 = 0.62). When drug ionization was considered (Log D), improved correlation coefficients were obtained for macrolides (R-2 = 0.98). However, other factors besides the drug solubility should be considered to explain and predict the partitioning of antibiotics during cheese-making.This work was supported by the Ministry of Science and Innovation (Madrid. Spain) (No. AGL-2013-45147-R) .Giraldo, J.; Igualada, C.; Cabizza, R.; Althaus, RL.; Beltrán Martínez, MC. (2022). Transfer of antibiotics from goat's milk to rennet curd and whey fractions during cheese-making. Food Chemistry. 392:1-7. https://doi.org/10.1016/j.foodchem.2022.1332181739

Variation of the chemical composition of waste cooking oils upon bentonite filtration

The chemical composition and the color of samples of waste cooking oils (WCOs) were determined prior to and after filtration on two different pads of bentonite differing in particle size. The volatile fraction was monitored by headspace solid-phase microextraction (HS-SPME) coupled with gas-chromatography, while the variation of the composition of the main components was analyzed by 1H NMR. Both techniques allowed the detection of some decomposition products, such as polymers, terpenes, and derivatives of the Maillard process. The analysis of the chemical composition prior to and after bentonite treatment revealed a tendency for the clays to retain specific chemical groups (such as carboxylic acids or double bonds), independent of their particle size. A pair comparison test was conducted in order to detect the sensory differences of the intensity of aroma between the WCO treated with the two different bentonites. In addition, characterization of the bentonite by means of powder X-ray diffraction (XRD) and thermogravimetric measurements (TG) was performed