Fresh extra virgin olive oil, with or without veil

Six different 300 kg batches of olive fruits are processed and the resulting six 20 kg batches of oil are collected at the end of the “decanter.” These batches of oil are subjected to four different water and solid particle separation treatments so as to obtain the following oil samples: veiled oil, filtered oil, “solid particle‐only” oil, and “water‐only” oil. The applied separation treatments show that water content has an important role in the degree of turbidity. High water content values (>0.2% w/w) are related to water activity values of >0.6 which are suitable for chemical and enzymatic reactions. The veiled oil samples are contaminated by microorganisms, but non‐proportional behavior occurs between the microbial cell count and the water and solid particle contents. Practical Applications: The results of this study recommend a multi‐approach method to characterize turbidity, based on control markers such as the degree of turbidity, water content and water activity, solid particle content, microbial contamination, and phenolic compound content. In this way, each degree of turbidity can be associated with a different level of risk of veiled extra virgin olive oil degradation during shelf life.

Section: Introductionmentioning

confidence: 99%

“…The presence of yeasts affects the quality of EVOO, modifying its sensory properties and phenolic compound content . Many sensory defects, such as fustiness, mouldiness, wine‐vinegary taste, and muddy sediment, have been associated with the microorganisms’ endogenous enzyme activity .…”

Section: Introductionmentioning

confidence: 99%

Physical, Chemical, and Biological Characterization of Veiled Extra Virgin Olive Oil Turbidity for Degradation Risk Assessment

Breschi

Guerrini

Domizio

et al. 2019

“…The major factors influencing emulsion rheology are disperse phase volume fraction, droplet size and droplet‐size distribution, rheology of component phases, and colloidal interactions. [ 54–56 ] Although the existing knowledge on unfiltered VOOs is little, these oils are reported as metastable emulsions or dispersions, involving emulsifying agents. [ 56,57 ] Several studies have reported that compounds such as diacylglycerols, monoacylglycerols, and phospholipids can act in freshly produced VOOs as natural emulsifiers or surfactants which contribute to form emulsions with the small amount of water present in the oil.…”

Section: Resultsmentioning

confidence: 99%

“…[ 54–56 ] Although the existing knowledge on unfiltered VOOs is little, these oils are reported as metastable emulsions or dispersions, involving emulsifying agents. [ 56,57 ] Several studies have reported that compounds such as diacylglycerols, monoacylglycerols, and phospholipids can act in freshly produced VOOs as natural emulsifiers or surfactants which contribute to form emulsions with the small amount of water present in the oil. [ 33,58,59 ] Besides, it is also worth remembering that the presence of this suspended matter is linked with fermentation and appearance of defects in the oil during its storage, due to its composition (proteins, sugars, phospholipids, phenolic compounds among others) and the presence the microorganisms such as bacteria, yeasts, and molds.…”

Section: Resultsmentioning

confidence: 99%

Effect of Clarification System on the Conservation of Virgin Olive Oil during Its Storage

Gila

Sánchez‐Ortíz

Beltrán

et al. 2020

The results obtained in this work explain how clarification systems can affect the conservation of virgin olive oils (VOOs) during the storage step. The evolution of the quality and sensory properties during the storage of VOOs clarified by different systems, vertical centrifugal separator (VCS) with minimal water addition and conical bottom settling tank (CBST), is studied at industrial scale for two different crop years. In general, VCS oils show a slight higher moisture and solid impurities content at the end of the storage step due to a higher emulsion grade (because of the emulsion generated) caused by the rotating movement of this clarification system. For the studied clarification systems, no remarkable differences are observed between the oils during their storage for quality indexes. However, these systems show differences regarding oil sensory properties. The VOOs clarified by VCS are characterized by a higher presence of phenol components, higher positive sensory attributes intensity, and higher lipoxygenase (LOX) aldehydes content during their storage. VOOs from CBST show lower phenol content, a higher “non‐LOX” volatiles content, and the presence of sensory defects during storage. Practical Applications: The results obtained in this work are very important in order to provide specific recommendations and scientific support based on objective data to improve VOO quality. As described in this study, the VCS with a minimal water addition can be a better option to produce VOO of improved quality. This clarification system is an efficient and quick operation that reduces the contact between oil and the remaining water and impurities during the storage step. The minimal water addition used in this clarification system allows obtaining VOOs with higher phenol content and positive sensory notes. This leads to prolong VOO shelf‐life and conservation during the storage stage, due to preservation of the quality indexes and minor components with antioxidant activity. Besides, this clarification system reduces the water consumption during oil clarification and generates a lower wastewater volume regarding conventional vertical centrifugation, and therefore can be considered more environmentally friendly.

“…Moreover, in our experimental conditions when argon (Ar) was used as the malaxation atmosphere, oil samples were characterized by the lowest values for the typical fruity flavor (Table 2). According to the literature [ 37–40 ] these results can be ascribed to the reduction of oxygen availability during malaxation which significantly decreased the production of aromatic compounds. [ 36,41,42,37 ]…”

Section: Resultsmentioning

confidence: 99%

Influence of the Atmosphere Composition during Malaxation and Storage on the Shelf Life of an Unfiltered Extra Virgin Olive Oil: Preliminary Results

Macaluso

Taglieri

Venturi

et al. 2020

The nutraceutical and organoleptic quality of the extra virgin olive oil (EVOO) depends on a process that begins with the olive ripening and ends with the packaging and storage. As the EVOO quality decay is mainly induced by the oxidation process, the gaseous composition of the atmosphere during both malaxation and storage can play a key role. Because of that, the aim of this research work is to determine the influence of the gaseous composition of the atmosphere used during malaxation and storage on an unfiltered EVOO shelf life, and to individuate the best “malaxation atmosphere × storage atmosphere” combination to adopt to more effectively slow down the oil quality decay rate during storage. The combined experimental conditions used during malaxation and storage significantly affect the quality decay rate of the EVOO over one year of storage for all the evaluated parameters. In conclusion, the gaseous composition of the atmosphere used during both malaxation and storage deeply affects the shelf life of the unfiltered EVOO as regards its chemical and sensory features, especially when air is used. On the contrary, the best results are obtained when an inert gas (nitrogen or argon) is used during both phases. Practical Applications: The regular consumption of EVOO represents one of the main cornerstones of the Mediterranean diet. According to the FDA (Food and Drug Administration), this product can be considered as a healthy food because of its extraordinary nutraceutical and organoleptic properties, so that if consumers consume half a tablespoon of olive oil per day—without increasing their daily calorie intake—they can significantly reduce the incidence of several degenerative diseases as well as the risks associated with them. The knowledge of the impact of different “malaxation atmosphere × storage atmosphere” combinations on the quality decay rate during storage of an unfiltered EVOO can allow to identify the best operating conditions to be used during its production and storage, in order to preserve the nutraceutical and organoleptic properties of this product over time, thus extending its commercial life in terms of both quality parameters and healthy properties.