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

• Published in: European journal of lipid science and technology Vol. 121; no. 11
• Main Authors: Breschi, Carlotta, Guerrini, Lorenzo, Domizio, Paola, Ferraro, Giovanni, Calamai, Luca, Canuti, Valentina, Masella, Piernicola, Parenti, Alessandro, Fratini, Emiliano, Fia, Giovanna, Zanoni, Bruno
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-11-2019
• Subjects: Biodegradation; biophenols; Chemical reactions; Decantation; Degradation; Microbial contamination; Microorganisms; Moisture content; Oils & fats; Olive oil; Organic chemistry; Phenolic compounds; Phenols; Risk assessment; scanning microscopy; Separation; Shelf life; Turbidity; veiled virgin olive oil; Water activity; Water content; Water pollution; Water purification; Water treatment; yeasts
• ISSN: 1438-7697; 1438-9312
• DOI: 10.1002/ejlt.201900195

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.
Microbial cell count, water content, water activity, and degree of turbidity are determined to understand the role of turbidity and microorganisms in veiled extra virgin olive oil. Confocal laser scanning microscopy experiments permit the observation of the morphology of the solid particles dispersed inside the organic matrix and the distribution of water inside the oil samples.