# A Narrative Review of Metabolomic Insights into Olive Oil's Nutritional Value
## 5 Challenges and Future Directions  
Metabolomics's involvement in nutrition and food production remains relatively unexplored. Its primary application lies in defining the composition of the VOO and EVOOcompounds to facilitate commercialization. However, defining metabolomic properties is time-consuming and prone to errors, necessitating standardized techniques [76]. A critical point concerns the processing methods used to produce olive oil, such as the extraction techniques and storage conditions. This could influence the chemical composition and bioactivity of olive oil as well as its metabolic profile. Future studies can have an important role in the investigation of the effects of different processing methods on the metabolomic profile of olive oil and its health-promoting properties. Understanding how processing factors affect the stability and bioavailability of bioactive compounds can guide industrial practices to produce high-quality olive oil with maximum health benefits [95]. Metabolomics definitions are particularly useful for quality control and authentication. Metabolomic changes in response to an individual's pathophysiological status, interactions with the environment, and genetic alterations are important factors for the evaluation of individual health assessments. Consequently, the significance of defining the metabolomic composition stems from the importance of different compounds in individual health [76]. \"Foodomics\" examines the combination of food and nutrition using techniques typical of \"omics\" sciences. A typical workflow involves sampling the nutritional source, preparing an extract containing the known or unknown metabolites of interest, identifying the sample, and acquiring data. In olive oil foodomics, studying metabolites through an omics approach helps to identify phenols and other relevant compounds [76]. The identification of metabolites involves the use of several methods that were previously mentioned. MS is the most used technique for identifying targeted and untargeted metabolites, and when coupled with GC, it permits identifying volatile compounds. Specific purification assays are instead essential for targeted metabolites, whereas untargeted metabolites yield a diverse range of compounds and require appropriate statistical analyses. Principal component analysis often represents the first attempt of analysis in this case [76; 96]. Various other techniques, such as UHPLC-Q-TOF-MS and LC-MS/MS, have been employed to identify compounds in olive oil, aiding authenticity evaluation [76]. The challenge in applying these techniques lies in the need to combine different methodologies to profile metabolites, and each technique presents its own set of difficulties. Furthermore, analysing these compounds is challenging, owing to their chemical diversity, variable concentrations, and enormous amounts of data generated from larger analyses, particularly untargeted ones [96]. Despite the difficulties in applying these methods and the need for workflows that are as standardized as possible, olive oil metabolomics is a promising area for future research. Metabolomics offers a transdisciplinary approach for studying the metabolites present in olive oil. It involves analytical chemistry, chemometrics, and bioinformatics to comprehensively understand olive oil's metabolome [97]. The approaches and methodologies applied varied depending on the purpose of the study. For example, single-class methodologies focus on specific classes of compounds such as phenolic compounds, pentacyclic triterpenenes, tocopherols, and phytosterols. They involve sample preparation, chromatographic separation, and detection using LC-MS or GC-MS. Multi-class approaches aim to simultaneously analyze multiple classes of compounds in olive oil. They offer a comprehensive view of olive oil composition and are becoming increasingly popular in metabolomic studies [96].