I Annual Workshop INSA-UB "The Universe of the Olive Oil" held in the Food and Nutrition Torribera Campus of the University of Barcelona, Spain, 11th November 2015

The Institute for Research on Nutrition and Food Safety (INSA-UB) was formed by research groups belonging to the Faculties of Pharmacy, Biology, Chemistry and Geography and History, as well as other UB-affiliated centers and hospitals. INSA-UB was created to meet the current society's needs for research, training and service provision in sectors related to the agro-food industry. Due to its nutritional, gastronomic, cultural and economic value, olive oil is a product of particular importance within the Mediterranean region. In order to disseminate the latest findings on different analytical and legal regulation aspects, as well as on the healthy properties of extra virgin olive oil, INSA-UB organized the workshop "The Universe of Olive Oil". Researchers from universities, hospitals and research centres, as well as a wide range of representatives of the Catalan administration, olive oil costumers and olive oil industry were brought together with the aim of strengthening the knowledge and cooperation, and to favor the interaction between the main stakeholders to promote actions for the valorization, innovation and development in this strategic area. About 100 representatives of the above mentioned sectors attended the Workshop, which was supported by the International Olive Council (IOC), the Faculty of Pharmacy of the University of Barcelona, and by the five Catalan Protected Designations of Origin of virgin olive oil. Experts from different research centers, together with promoters and representatives of the local government, presented their recent results and current trends about olive oil. The Workshop was organized into different sessions, focused on different topics: olive oil quality, authenticity and control, healthy effects and the role played within the 'Mediterranean culture gastronomy' understanding that the best option to face the key challenges of the sector is a comprehensive approach in which subject areas and all stakeholders can complement and enhance themselves

Volatile thiols in coffee: A review on their formation, degradation, assessment and influence on coffee sensory quality

Thiols are among the compounds that have the greatest impact on the flavor of coffee. Due to their extremely low odor thresholds, they have a significant sensory impact even at very low concentrations. Thiols are formed during coffee roasting and are described as the key odorants responsible for the typical 'coffee' and 'roasty' odor notes, greatly influencing the sensory characteristics of coffee. They are particularly reactive and prone to oxidation; their rapid depletion after preparation of a coffee brew and during storage of roasted coffee has been associated with sensory quality decrease and coffee going stale. For these reasons, their determination and insight into their formation and degradation mechanisms could help us to preserve the sensory quality of coffee and to modulate its sensory features. Coffee aroma has been widely studied in recent decades, and it has become evident that the role of certain volatile thiols is paramount. Nevertheless, a limited number of studies have specifically addressed this class of compounds, and several aspects have not yet been satisfactorily elucidated. The aim of this review is to provide an overview of the current state on knowledge about coffee thiols, focusing on their occurrence, determination, sensory impact, formation and evolution in roasted and brewed coffee

Analysis of volatile thiols in alcoholic beverages by simultaneous derivatization/extraction and liquid chromatography-high resolution mass spectrometry

A simultaneous derivatization/extraction method followed by liquid chromatography electrospray-high resolution mass spectrometry for the determination of volatile thiols in hydroalcoholic matrixes was optimized and used to identify and quantify volatile thiols in wine and beer samples. The method was evaluated in terms of sensitivity, precision, accuracy and selectivity. The experimental LOQs of eleven thiols tested ranged between 0.01 ng/L and 10 ng/L. Intra-day relative standard deviation (RSD) was in general lower than 10% and inter-day RSD ranged between 10% and 30%. Recovery in the model and real matrixes ranged from 45% to 129%. The method was then applied for the analysis of four white wines and six beers. Five out of the eleven reference thiols were identified and quantified in the samples analysed. The non-target approach, carried out by monitoring the diagnostic ion at m/z 275.9922 [C13H10ONSe]+ in the fragmentation spectrum, allowed detecting, in the same samples, fourteen non-target thiols

Quality losses in virgin olive oil due to washing and short-term storage before olive milling

To identify critical points during olive mill pre-processing operations, the effect of the closed circuit washing stage on the olives microbiological contamination and the influence of the successive short-term storage on olives and VOO quality were evaluated. Microbiological, physical and chemical parameters were assessed in olives and oils at three mill pre-processing stages: reception, washing and short-term storage. Olive washing in closed loop systems was shown to be a critical control point at the olive mill due to microbiological cross-contamination and fruit physical damage. Moreover, when the olives were short-term stored before oil extraction positive VOO sensory attributes decreased by as much as one point of intensity, as justified by the changes observed in phenolic and lipoxygenase derived compounds. These results confirm the high risk of fruit cross-contamination due to the poor hygiene of the water used in olive mills to wash olive, and point o ut t he e ffect of on VOO quality of a common practice such as short term silo storage of olives

Evolution of endogenous enzyme activities and virgin olive oil characteristics during Chétoui and Chemlali olive ripening

The composition and biochemical characteristics of olive fruits, mainly olive enzymes system, are crucial in determining the final quality of virgin olive oil (VOO). Thus, olives endogenous olive enzyme activities were studied during Chétoui and Chemlali olive ripening. The compositional quality of the corresponding VOO was also studied. Peroxidase (POX) and β-glucosidase activities increased during olives ripening. However, polyphenoloxidase activity decreased slowly. Moreover,the POX enzyme appears to play an essential role in determining VOO total phenol amounts, as the decrease in phenol content registered during olive ripening coincided with the increase in POX activity. A positive correlation between oil antioxidant activity and the total phenol content was established for both the olive cultivars studied. With regard to pigments, chlorophyll content wasmuch higher than that of carotenoids in both Chétoui and Chemlali oils. Moreover, different trends in chlorophyll and carotenoid contents were observed, depending on the olive cultivar. Concerning volatile compounds, our results showed that the highest content of total C6, C5 LOX compounds and pentene dimers was observed at a RI of approximately 3 for both cultivars. However, C6 alcohols and total C5 compounds decreased in Chétoui and Chemlali oils, respectively, during olive ripening

Direct chemical profiling of olive (Olea europaea) fruit epicuticular waxes by direct electrospray-ultrahigh resolution mass spectrometry

In the present paper, an ESI-Orbitrap method is proposed for the direct chemical profiling of epicuticular wax (EW) from Olea europaea fruit. It constitutes a rapid and efficient tool suitable for a wide-ranging screening of a large number of samples. In a few minutes, the method provides a comprehensive characterization of total EW extracts, based on the molecular formula of their components. Accurate mass measurements are obtained by UHRMS, and compositional restrictions are set on the basis of the information available from previous studies of olive EW. By alternating positive and negative ESI modes within the same analysis, complementary results are obtained and a wide range of chemical species is covered. This provides a detailed compositional overview that otherwise would only be available by applying multiple analytical techniques

Subzero Temperature Storage to Preserve the Quality Attributes of Veiled Virgin Olive Oil

Unfiltered olive oils (UO) have gained popularity in the global market, but they lose their quality characteristics faster than filtered oils (FO). In this work, refrigeration and freezing temperatures were explored to maintain UO quality features during storage. A full factorial design was applied to an UO and to the same oil after filtration to evaluate the effect of storage temperature (room temperature, 4 ◦C and –20 ◦C) and freezing speed (slow-freezing, in the freezer at −20 ◦C and fast-freezing, in a bath of liquid nitrogen). Official quality parameters, polar and nonpolar phenolic compounds, oxidative stability index, volatile compounds and descriptive sensory profile were measured periodically over 24 months of storage in the dark. Storage temperature influenced the quality of both UO and FO, but in different ways. At non-freezing temperature, UO experienced a severe decrease in its sensory quality compared to FO, mainly due to the hydrolysis of secoiridoids and degradation of the volatile fraction, but storage at −20 ◦C allowed to effectively preserve UO quality traits, thus resulting as a suitable strategy to increase the shelf-life of UO to satisfy the demand of consumers for this particular product. The results showed that slow-freezing was the most appropriate method for freezing.info:eu-repo/semantics/publishedVersio

Thiols in brewed coffee: assessment by fast derivatization and liquid chromatography high resolution mass spectrometry

In the present paper, we present a simple, reliable, selective and sensitive method for the identification and quantification of volatile thiols at trace levels in coffee brews. A simultaneous derivatization/ extraction procedure followed by liquid chromatography electrospray high-resolution mass spectrometry is proposed and adapted to coffee brew matrix, and the performance of the method is evaluated. The linearity, sensitivity, recovery and both the intra-day and inter-day accuracy were all satisfactory. According to established identification criteria, seven target and nine non-target thiols were identified and quantified in coffee brew samples. Several of them are reported here for the first time in coffee brews, and our results are in agreement with previously reported results for coffee powder analyzed using similar analytical approach

Composition and Nutritional Value of Acid Oils and Fatty Acid Distillates Used in Animal Feeding

Acid oils (AO) and fatty acid distillates (FAD) are oil refining by-products rich in free fatty acids. The objective of this study is their characterization and the identification of their sources of variability so that they can be standardized to improve their use as feed ingredients. Samples (n=92) were collected from the Spanish market and the MIU value (sum of moisture, insoluble impurities, and unsaponifiable matter), lipid classes, fatty acid composition, and tocol content were analyzed. Their composition was highly variable even between batches from the same producer. As FAD originated from a distillation step, they showed higher free fatty acid amounts (82.5 vs 57.0 g/100 g, median values), whereas AO maintained higher proportions of moisture, polymers, tri-, di-, and monoacylglycerols. Overall, the MIU value was higher in AO (2.60-18.50 g/100 g in AO vs 0.63-10.44 g/100 g in FAD), with most of the contents of insoluble impurities being higher than those in the guidelines. Tocol and fatty acid composition were influenced by the crude oil's botanical origin. The calculated dietary energy values were, in general, higher for AO and decreased when a MIU correction factor was applied. The analytical control and standardization of these by-products is of the outmost importance to revalorize them as feed ingredients. Keywords: fat by-products, acid oils, fatty acid distillates, animal feed, nutritional value, poultry, pig, MIU value, energ

Oxidative Quality of Acid Oils and Fatty Acid Distillates Used in Animal Feeding

Acid oils (AO) and fatty acid distillates (FAD) are byproducts from chemical and physical refining of edible oils and fats, respectively. Their high energy value makes their upcycling interesting as alternatives to conventional fats in animal feeding. The objective of this study is to characterize their oxidative quality and to provide recommendations about their evaluation for animal feeding purposes. The oxidation status (peroxide value (PV), p-Anisidine value (p-AnV), % polymeric compounds (POL)), the oxidative stability (induction time by the Rancimat at 120 ◦C (IT)), the fatty acid composition (FA), and tocopherol and tocotrienol content of 92 AO and FAD samples from the Spanish market were analyzed. Both AO and FAD showed low PV (0.8 and 1 meq O2/kg); however, p-AnV was higher in FAD (36.4 vs. 16.4 in AO) and POL was higher in AO (2.5% vs. not detected in FAD) as a consequence of the type of refining process. The botanical origin of AO and FAD influenced FA and tocol composition, and they influenced IT. A high variability was observed for most analyzed parameters, reinforcing the need for standardizing AO and FAD to obtain reliable feed ingredients and to include primary and secondary oxidative parameters within their quality control