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

Volatile profile of matured Tronchón cheese affected by oxytetracycline in raw goat milk

[EN] The presence of antibiotics in milk destined for cheese production may affect the biological processes responsible for the formation of volatile compounds, leading to alterations in the characteristic cheese flavor expected by consumers. The aim of this study was to evaluate the effect of the presence of oxytetracycline in goat milk on the volatile profile of ripened cheeses. Traditional mature Tronchón cheeses were manufactured from raw goat milk spiked with different concentrations of oxytetracycline (50, 100, and 200 ug/kg). Cheese made from antibiotic-free goat milk was used as control. We analyzed the residual amounts of the antibiotic and the volatile profile of the experimental cheeses on a fortnightly basis during maturation using liquid chromatography tandem mass spectrometry and then solid-phase microextraction followed by gas chromatography-mass spectrometry. Our results suggested that oxytetracycline was widely transferred from milk to cheese: drug concentrations in the cheeses were 3.5 to 4.3 times higher than those in raw milk. Although the residual amounts of oxytetracycline significantly decreased during maturation (88.8 to 96.5%), variable amounts of residues remained in cheese matured for 60 d (<10 to 79 ug/kg). In general, the presence of oxytetracycline in goat milk did not affect the volatile profile of Tronchón cheeses; volatile profile was significantly modified by ripening time. Still, the presence of oxytetracycline residues in cheeses ripened for 60 d could be of great concern for public health.This work is part of the AGL-2013-45147-R funded by the Ministry of Science and Innovation (Madrid. Spain). The authors thank the Research and Development Support Program, "Ayudas para movilidad dentro del Programa para la Formación de Personal Investigador" (2.016) of Universitat Politècnica de València (Spain), allowing Paloma Quintanilla to perform a predoctoral stay at the Food Quality and Design Group, Wageningen University and Research (Wageningen, the Netherlands). The authors state that they have no conflicts of interest.Quintanilla-Vázquez, PG.; Hettinga, K.; Beltrán Martínez, MC.; Escriche Roberto, MI.; Molina Pons, MP. (2020). Volatile profile of matured Tronchón cheese affected by oxytetracycline in raw goat milk. Journal of Dairy Science. 103(7):6015-6021. https://doi.org/10.3168/jds.2019-16510S601560211037Attaie, R., Bsharat, M., Mora-Gutierrez, A., & Woldesenbet, S. (2015). Short communication: Determination of withdrawal time for oxytetracycline in different types of goats for milk consumption. Journal of Dairy Science, 98(7), 4370-4376. doi:10.3168/jds.2014-8616Beltrán, M. C., Althaus, R. L., Molina, A., Berruga, M. I., & Molina, M. P. (2015). Analytical strategy for the detection of antibiotic residues in sheep and goat’s milk. Spanish Journal of Agricultural Research, 13(1), e0501. doi:10.5424/sjar/2015131-6522Cabizza, R., Rubattu, N., Salis, S., Pes, M., Comunian, R., Paba, A., … Urgeghe, P. P. (2017). Transfer of oxytetracycline from ovine spiked milk to whey and cheese. International Dairy Journal, 70, 12-17. doi:10.1016/j.idairyj.2016.12.002Cabizza, R., Rubattu, N., Salis, S., Pes, M., Comunian, R., Paba, A., … Urgeghe, P. P. (2018). Impact of a thermisation treatment on oxytetracycline spiked ovine milk: Fate of the molecule and technological implications. LWT, 96, 236-243. doi:10.1016/j.lwt.2018.05.026Castillo, I., Calvo, M. V., Alonso, L., Juárez, M., & Fontecha, J. (2007). Changes in lipolysis and volatile fraction of a goat cheese manufactured employing a hygienized rennet paste and a defined strain starter. Food Chemistry, 100(2), 590-598. doi:10.1016/j.foodchem.2005.09.081Curioni, P. M. G., & Bosset, J. O. (2002). Key odorants in various cheese types as determined by gas chromatography-olfactometry. International Dairy Journal, 12(12), 959-984. doi:10.1016/s0958-6946(02)00124-3Delgado, F. J., González-Crespo, J., Cava, R., García-Parra, J., & Ramírez, R. (2010). Characterisation by SPME–GC–MS of the volatile profile of a Spanish soft cheese P.D.O. Torta del Casar during ripening. Food Chemistry, 118(1), 182-189. doi:10.1016/j.foodchem.2009.04.081Delgado, F. J., González-Crespo, J., Cava, R., & Ramírez, R. (2011). Formation of the aroma of a raw goat milk cheese during maturation analysed by SPME–GC–MS. Food Chemistry, 129(3), 1156-1163. doi:10.1016/j.foodchem.2011.05.096Gajda, A., Nowacka - Kozak, E., Gbylik - Sikorska, M., & Posyniak, A. (2017). Tetracycline antibiotics transfer from contaminated milk to dairy products and the effect of the skimming step and pasteurisation process on residue concentrations. Food Additives & Contaminants: Part A, 35(1), 66-76. doi:10.1080/19440049.2017.1397773Halling-Sørensen, B., Lykkeberg, A., Ingerslev, F., Blackwell, P., & Tjørnelund, J. (2003). Characterisation of the abiotic degradation pathways of oxytetracyclines in soil interstitial water using LC–MS–MS. Chemosphere, 50(10), 1331-1342. doi:10.1016/s0045-6535(02)00766-xHettinga, K. A., van Valenberg, H. J. F., & van Hooijdonk, A. C. M. (2008). Quality control of raw cows’ milk by headspace analysis. International Dairy Journal, 18(5), 506-513. doi:10.1016/j.idairyj.2007.10.005Katla, A.-K., Kruse, H., Johnsen, G., & Herikstad, H. (2001). Antimicrobial susceptibility of starter culture bacteria used in Norwegian dairy products. International Journal of Food Microbiology, 67(1-2), 147-152. doi:10.1016/s0168-1605(00)00522-5Loftin, K. A., Adams, C. D., Meyer, M. T., & Surampalli, R. (2008). Effects of Ionic Strength, Temperature, and pH on Degradation of Selected Antibiotics. Journal of Environmental Quality, 37(2), 378-386. doi:10.2134/jeq2007.0230McSweeney, P. L. H., & Sousa, M. J. (2000). Biochemical pathways for the production of flavour compounds in cheeses during ripening: A review. Le Lait, 80(3), 293-324. doi:10.1051/lait:2000127Padilla, B., Belloch, C., López-Díez, J. J., Flores, M., & Manzanares, P. (2014). Potential impact of dairy yeasts on the typical flavour of traditional ewes’ and goats’ cheeses. International Dairy Journal, 35(2), 122-129. doi:10.1016/j.idairyj.2013.11.002Quintanilla, P., Beltrán, M. C., Molina, A., Escriche, I., & Molina, M. P. (2019). Characteristics of ripened Tronchón cheese from raw goat milk containing legally admissible amounts of antibiotics. Journal of Dairy Science, 102(4), 2941-2953. doi:10.3168/jds.2018-15532Sierra, D., Contreras, A., Sánchez, A., Luengo, C., Corrales, J. C., Morales, C. T., … Gonzalo, C. (2009). Short communication: Detection limits of non-β-lactam antibiotics in goat’s milk by microbiological residues screening tests. Journal of Dairy Science, 92(9), 4200-4206. doi:10.3168/jds.2009-2101Souza, C. F. V. de, Dalla  Rosa, T., & Ayub, M. A. Z. (2003). Changes in the microbiological and physicochemical characteristics of Serrano cheese during manufacture and ripening. Brazilian Journal of Microbiology, 34(3). doi:10.1590/s1517-8382200300030001

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 &ldquo;Scotta&rdquo; 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 &deg;C) and animal origin (4% E:S, 4 h, 40 &deg;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 &plusmn; 0.2 vs. 13 &plusmn; 1 mg mL&minus;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

ntegration in the foreign trade processes of the supply chain of the Ilo port terminal during 2019

La presente tesis tiene como principal objetivo analizar la cadena de suministros del Terminal Portuario de Ilo, con la finalidad de plantear mejoras que permitan un mejor desarrollo en la operatividad del terminal, el cual se encuentra administrado por la Empresa Nacional de Puertos, en adelante ENAPU. Este terminal portuario es el último bajo la administración de la empresa estatal en el Pacifico, el cual recibe muchas críticas sobre su operación, por lo que se desea saber cómo es el funcionamiento y operatividad, además de cómo se ejecuta la interacción con los principales actores de la cadena de suministros. Ahora bien, para esta investigación se tomará como base teórica la gestión de la cadena de suministros global enfocada al sector portuario. La metodología que se utilizará para el desarrollo de esta investigación, será el análisis de documentos académicos, además de la utilización de herramientas como entrevistas a especialistas pertenecientes a instituciones de sectores portuarios, públicos y privados, que permitirán profundizar el análisis de la cadena de suministros portuaria.The main objective of this thesis is to analyze the supply chain of the Ilo Port Terminal, in order to propose improvements that allow a better development in the operation of the terminal, which is managed by the National Ports Company, hereinafter ENAPU. This port terminal is the last one under the administration of the state company in the Pacific, which receives a lot of criticism about its operation, so we want to know how it works and how it operates, as well as how the interaction with the main actors is executed. of the supply chain. Now, for this research, the management of the global supply chain focused on the port sector will be taken as a theoretical basis. The methodology that will be used for the development of this research will be the analysis of academic documents, in addition to the use of tools such as interviews with specialists belonging to institutions in the port, public and private sectors, which will allow deepening the analysis of the supply chain port.Tesi