Sviluppo di composti di ossidazione in olio extra vergine di oliva durante la frittura: influenza della cultivar e del processo di estrazione

An experimental investigation was carried out in order to assess the influence of the cultivar and of the oil extraction process on the evolution of the oxidation compounds in extra virgin olive oil during frying. In order to do this oils from two Sardinian cultivars, obtained by two different oil extraction processes have been used to fry potato chips. The oils extracted from the potato chips were analyzed to evaluate the oxidative degradation and the antioxidant capacity. The results obtained showed that the differences observed for the oxidation triacylglycerol and polar compounds content in the extracted oils reflect the differences observed in the starting oils, while, as regards the triacylglycerol oligopolymers, the oils showed a different behavior during frying, indicating a slower polymerization rate in the oils characterized by a better quality. Un’indagine sperimentale è stata condotta allo scopo di valutare l’influenza della cultivar e del processo di estrazione dell’olio sullo sviluppo di composti di ossidazione in olio extra vergine di oliva sottoposto a frittura. Allo scopo oli monovarietali, provenienti da due cultivar sarde, ottenuti applicando due differenti tecnologie di estrazione sono stati impiegati per la frittura di patatine. L’olio estratto da queste è stato sottoposto ad indagini analitiche utili per la valutazione dei fenomeni di ossidazione e della capacità antiossidante. I risultati ottenuti hanno evidenziato che le differenze riscontrate per il contenuto in triacilgliceroli ossidati e in composti polari negli oli estratti dalle patate rispecchiavano quelle degli oli di partenza, mentre per il contenuto in oligopolimeri dei triacilgliceroli è stato evidenziato un comportamento differente degli oli nel corso della frittura, ad indicazione di una minore polimerizzazione negli oli caratterizzati da migliore qualità iniziale

Focaccia Italian Flat Fatty Bread Food Chemistry

Focaccia is a typical bakery product of many Italian regions, and it shows variants depending on the productive area. Today, focaccia is largely appreciated for its sensory properties and has its own market. It is usually consumed, still hot, as a "street food," immediately after its production. Focaccia is made of a few simple ingredients-flour, water, fatty substances (oil or lard), yeast, and salt-but a myriad of nuanced differences are obtainable by topping it, prior to cooking, with fresh tomato, onions, potatoes, olives, cheese, etc. or flavoring it with herbs (rosemary, sage, oregano, etc.). Durum wheat, re-milled semolina is used in the production of some types of focaccia. Olive oil, notably extra-virgin olive oil, is an essential ingredient in many types of focaccia. Focaccia usually appears as a circular flat bread, single layered, oily, and variously topped. The productive steps of the various focaccia types are: mixing, kneading, leavening, flattening, proofing, and baking. In the past, only a sourdough-based prolonged productive process was performed; however, today, fresh compress baker's yeast is used in the majority of bakeries to prepare focaccia. © 2011 Elsevier Inc. All rights reserved

Measure of thermo-oxidation of vegetable oils microwave-heated in model systems

A study was conducted to evaluate the extent of thermo-oxidative degradation in different types of oils (sunflower, soybean, peanut, and virgin of olive) microwave heated in model systems. The acidity determination, peroxide value, specific UV spectrophotometric constants, and p-anisidine value - useful for a basic evaluation - were carried out. Polar compounds and the single classes of substances constituting them were also determined to better estimate the extent of oxidative and hydrolytic degradation of the oils under study. The obtained results showed a high oxidative degradation degree of the oils that, however, seemed to be correlated to the poly-enoic fatty add content and to the presence of pro-oxidant substances. The hydrolytic degradation, otherwise, resulted moderate