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Received Oct 26, 2017; Accepted Jan 2, 2018

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

1. Introduction

Known as a key component in the Mediterranean diet for centuries, extra virgin olive oil (EVOO) has become globally recognized and appreciated by consumers due to its unique sensory characteristics and high nutritional values. In recent years, there has been considerable interests in correlating monounsaturated fatty acids (mainly oleic acid) and minor components (phenolic compounds, alpha-tocopherol and carotenoids, squalene, simple triterpenes, and volatile compounds) in EVOO with health benefits e.g., antihypertensive activity [1], chemopreventive activity [2], tumor-inhibitory activity [3], and anti-inflammatory activity [4] and positive sensory attributes [5–7]. However, due to high levels of unsaturated fatty acids and the presence of endogenous enzymes such as lipase, polyphenol oxidase, and peroxidase, EVOO is also prone to lipid oxidation and enzymatic hydrolysis which favors autoxidation [8–10]. EVOO oxidation is highly dependent on factors including the storage of olive fruit prior to processing [11], the techniques of oil extraction [12], the exposure degree of oxygen, light, and temperature [13], and the packaging [14] and storage conditions of the final product [15], which could greatly change the chemical composition of the oil, leading to unpleasant off-flavors and eventually degrading the quality.

For consumers, one of the most important characteristics in EVOO is freshness, as freshness is typically associated with high quality and ensures food safety [16]. The term “shelf life” is commonly referred to when determining the freshness and consumer acceptability of EVOO [17]. Specifically, EVOO shelf life could be defined as the length of time under normal storage conditions within which no off-flavors or defects are developed and quality parameters are within accepted limits for this commercial category [18]. Consumers rely on shelf-life determinations to differentiate between products that are acceptable for consumption from those that are no longer acceptable. Thus, it is obligatory for the olive oil industry to monitor oil quality throughout the production line [19] and to be able to provide realistic information on shelf-life prediction considering the temperature changes and light exposure during transport and commercial activities [20].

EVOO shelf-life testing is often conducted...
            
                       
            
     
                      
 

          
               
       
   

            
             

  

  

      

                  

  

  

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