Chemical characteristics,oxidation and proteolysis in cheese produced from fresh or stored milk subjected to heat treatments

Cheese produced from fresh, stored or heat pretreated (65°C for 15 s) milk subjected to pasteurisation (72°C or 77°C for 15 s) was studied for chemical characteristics and proteolysis after 4 and 21 days of storage. Antioxidant activity was higher in cheese from fresh milk than in cheese from stored and heat pretreated milk. Malondialdehyde content as an index of lipid oxidation increased in cheese made with pretreated and preserved milk than in cheese made with fresh milk. Antioxidant activity and lipid oxidation were not significantly affected by pasteurisation temperature. Proteolysis increased during cheese maturation regardless of milk heat treatments.     

Supercritical CO2 extraction of oleanolic acid from grape pomace

In this work, we investigated the possibility to extract oleanolic acid through supercritical fluid extraction from waste materials such as grape pomace, which can represent a yet unexploited source of highly added‐value products. Preliminary supercritical fluid extractions were performed on dried grape skin samples and compared with solid–liquid extraction. After optimising extraction parameters such as temperature, pressure and extraction time, the ratio between supercritical and solid–liquid extraction yields was approximately 1/5. Supercritical CO₂ extractions were also carried out on dried grape pomace samples. In this case, the ratio between supercritical and solid–liquid extraction yields was increased up to 1/3, thanks to a combination of static and dynamic extraction and the use of ethanol as modifier. This extraction technique proved successful in extracting oleanolic acid from grape pomace samples with extraction yields that were comparable with those obtained with well‐established extraction techniques such as solid–liquid extraction.     

A novel method to obtain chitosan/DNA nanospheres and a study of their release properties

Polysaccharides and other cationic polymers have recently been used in pharmaceutical research and industry for their properties to control the release of antibiotics, DNA, proteins, peptide drugs or vaccines, and they have also been extensively studied as non-viral DNA carriers for gene delivery and therapy. Among them, chitosan is the most used since it can promote long-term release of incorporated drugs. This work is focused on the preparation of chitosan and chitosan/DNA nanospheres by using a novel and simple osmosis-based method, recently patented. The morphology of chitosan/DNA particles is spherical (as observed by scanning electron microscopy, SEM) and the nanospheres' average diameter is 38 ± 4?nm (obtained by dynamic light scattering, DLS). With this method, DNA is incorporated with high yield (up to 30%) and the release process is gradual and prolonged in time. The novelty of the reported method resides in the general applicability to various synthetic or natural biopolymers. Solvent, temperature and membrane cut-off are the physicochemical parameters that one is able to use to control the overall osmotic process, leading to several nanostructured systems with different size and shape that may be used in several biotechnological applications.     

Near-infrared spectroscopy: A possible routine analysis to detect the use of frozen curds in the production of Buffalo Mozzarella cheese

Mozzarella di Bufala Campana is a pasta filata cheese with a Protected Designation of Origin whose specifications require the use of fresh milk, forbidding the use of frozen curds. The goal is to develop a routine analysis to identify frozen curd presence. The Buffalo Mozzarella samples were analysed by the near-infrared analytical technique, and the spectral data were processed through an artificial neural network. The results make it possible to identify the use of frozen curd in samples of Buffalo Mozzarella for up to 9 days of storage. The model reported very high accuracy either in training (0.5% of bad prediction) or in tests (6.8% of bad prediction).