Co-milling process of olives and oleaginous matrices with high nutritional value: a preliminary characterisation of the obtained oils.

Extra virgin olive oil (EVOO), grape seeds (GS) and pomegranate seeds (PS) are very popular for human consumption because of their nutraceutical properties. A co-milling of olives with GS or PS was carried out with the aim of a preliminary study of the lipidic and phenolic characteristics of the obtained vegetable oils, also during their shelf life. Results show that the use of GS and PS in the olive co-milling enriches the oil in healthy compounds, such as punicic acid and γ-tocopherol. However, the co-milling process must be re-evaluated, since the compositional profile of the co-milled oils is just slightly different from EVOO. The oxidative state of the oils obtained suggests the use of a protective packaging combined with small containers in order to ensure a rapid consumption. With an appropriate formulation the co-milled oils could bring health-positive compounds and, simultaneously, raw materials could be valorised.

Deodorization of sunflower oil by high voltage electric field as a nonthermal method sunflower oil refining by electric field.

In this study, the high voltage electric field (HVEF) method was used for deodorization of sunflower oil to omit drawbacks of an established industrial method including long time, high energy, chemicals and water consumption, loss of bioactive compounds, and formation of some contaminants due to exposure to heat. Response surface methodology (RSM) was employed to find the optimal values of processing parameters. The effects of voltage (5-15 kV), clay (0-1%), electrolyte concentration (0-50 mM), the number of electrodes (1-5 pairs), and electrodes distance (1-3 cm) on the volatile compounds and tocopherols content were investigated by HS-SPME-GC/MS and HPLC, respectively. The optimal processing conditions were determined to be a voltage of 5 kV, a distance of 1 cm between the electrodes and a number of five pairs of electrodes. The amount of bleaching clay and electrolyte concentration were zero under optimal conditions. The refining process by HVEF removed 32.33% of the volatile compounds from crude sunflower oil, while the industrial refining process reduced the volatile compounds by only 17.78%. Results indicated no change was observed in the tocopherols content of refined sunflower oil by HVEF method. Based on PCA results, HVEF-treated sample not only contained the lowest concentration of volatile compounds but also was the most similar to crude sample in terms of volatile compounds composition. PRACTICAL APPLICATION: The oil refining process consists of four main stages, the last of which is deodorization. This step involves injecting steam at a temperature of about 240°C, under vacuum for about 50 min. High voltage electric field (HVEF) was able to reduce the number of volatile compounds, while no change was made in the tocopherol content of sunflower oil samples. It also does not form contaminant such as 3-monochloropropane-1,2-diol fatty acid esters and glycidyl fatty acid esters. There is no need to apply the vacuum in HVEF refining, which reduces the production cost and makes the process flow straightforward as well as rapid. This research helps to propagate green refining procedures of vegetable oils in food plants.

Enzymatic Digestion of Calf Fleshing Meat By-Products: Antioxidant and Anti-Tyrosinase Activity of Protein Hydrolysates, and Identification of Fatty Acids.

The food waste reduction through an efficient recovery of its valuable building molecules has become an important topic with a positive effect on the economy and the environment. In this work, the revalorization of slaughterhouse calf fleshing meat through its enzymatic hydrolysis is proposed. The proteolytic activity of 11 enzymes was initially screened and the four most efficient enzymes (papain, trypsin, pancreatin, and bromelain) were selected. The molecular profiling of the different protein/peptide fractions by the Linear Trap Quadrupole-OrbiTrap technique showed compositional differences due to the specificity of the enzymes' cleavage sites. In order to find a potential reuse of these hydrolysates, the analysis of antioxidant and, for the first time on fleshing meat hydrolysates, of anti-tyrosinase activities, was performed. Papain-digested samples were those showing the highest inhibition activity of tyrosinase enzyme (55.6%) as well as the highest antioxidant activity (3.52 g TEAC/L). In addition, the composition analysis of the lipid fraction was performed. The mono-unsaturated fatty acids resulted to be the most abundant lipid in all the samples with the exception of pancreatin-treated hydrolysates in which poly-unsaturated fatty acids were predominant. The present results seemed to support a possible valorization of isolated fractions from calf fleshing by-products, as food or feed ingredients, by the implementation of fraction isolation within the meat-processing pipeline.