High-resolution mass spectrometry to evaluate the influence of cross-breeding segregating populations on the phenolic profile of virgin olive oils

The Tower of Babel of Pharma-Food Study on Extra Virgin Olive Oil Polyphenols

Much research has been conducted to reveal the functional properties of extra virgin olive oil polyphenols on human health once EVOO is consumed regularly as part of a balanced diet, as in the Mediterranean lifestyle. Despite the huge variety of research conducted, only one effect of EVOO polyphenols has been formally approved by EFSA as a health claim. This is probably because EFSA’s scientific opinion is entrusted to scientific expertise about food and medical sciences, which adopt very different investigative methods and experimental languages, generating a gap in the scientific communication that is essential for the enhancement of the potentially useful effects of EVOO polyphenols on health. Through the model of the Tower of Babel, we propose a challenge for science communication, capable of disrupting the barriers between different scientific areas and building bridges through transparent data analysis from the different investigative methodologies at each stage of health benefits assessment. The goal of this work is the strategic, distinctive, and cost-effective integration of interdisciplinary experiences and technologies into a highly harmonious workflow, organized to build a factual understanding that translates, because of trade, into health benefits for buyers, promoting EVOOs as having certified health benefits, not just as condiments.

Phenolic variability in fruit from the ‘Arbequina’ olive cultivar under Mediterranean and Subtropical climatic conditions

In the present work, we compared the phenol content and composition of fruit from the ‘Arbequina’ cultivar in four Mediterranean (in Andalucía, Southern Iberian Peninsula) and two Sub-Tropical (Canary Islands) locations throughout the harvest period. Two Mediterranean and two Sub-Tropical locations were maintained with drip irrigation, while the remaining two Mediterranean locations were in dry farming. Water availability and harvest date seemed to play more important roles than air temperature on the phenolic content and most of the studied components. The variability associated with location was a result of the high values observed in the two Mediterranean locations in dry farming, with respect to the other four maintained with drip irrigation. Few differences were found among the four drip-irrigated locations, despite the fact that two were Mediterranean and the other two Sub-Tropical. In addition, a sharp decrease was observed during the harvest period for phenolic content and most of the phenolic compounds.

Application of High Resolution Mass Spectrometric methods coupled with chemometric techniques in olive oil authenticity studies - A review

Extra Virgin Olive Oil (EVOO), the emblematic food of the Mediterranean diet, is recognized for its nutritional value and beneficial health effects. The main authenticity issues associated with EVOO's quality involve the organoleptic properties (EVOO or defective), mislabeling of production type (organic or conventional), variety and geographical origin, and adulteration. Currently, there is an emerging need to characterize EVOOs and evaluate their genuineness. This can be achieved through the development of analytical methodologies applying advanced "omics" technologies and the investigation of EVOOs chemical fingerprints. The objective of this review is to demonstrate the analytical performance of High Resolution Mass Spectrometry (HRMS) in the field of food authenticity assessment, allowing the determination of a wide range of food constituents with exceptional identification capabilities. HRMS-based workflows used for the investigation of critical olive oil authenticity issues are presented and discussed, combined with advanced data processing, comprehensive data mining and chemometric tools. The use of unsupervised classification tools, such as Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA), as well as supervised classification techniques, including Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), Partial Least Square Discriminant Analysis (PLS-DA), Orthogonal Projection to Latent Structure-Discriminant Analysis (OPLS-DA), Counter Propagation Artificial Neural Networks (CP-ANNs), Self-Organizing Maps (SOMs) and Random Forest (RF) is summarized. The combination of HRMS methodologies with chemometrics improves the quality and reliability of the conclusions from experimental data (profile or fingerprints), provides valuable information suggesting potential authenticity markers and is widely applied in food authenticity studies.

Using Wild Olives in Breeding Programs: Implications on Oil Quality Composition

A wide genetic diversity has been reported for wild olives, which could be particularly interesting for the introgression of some agronomic traits and resistance to biotic and abiotic stresses in breeding programs. However, the introgression of some beneficial wild traits may be paralleled by negative effects on some other important agronomic and quality traits. From the quality point of view, virgin olive oil (VOO) from olive cultivars is highly appreciated for its fatty acid composition (high monounsaturated oleic acid content) and the presence of several minor components. However, the composition of VOO from wild origin and its comparison with VOO from olive cultivars has been scarcely studied. In this work, the variability for fruit characters (fruit weight and oil content, OC), fatty acid composition, and minor quality components (squalene, sterols and tocopherols content and composition) was studied in a set of plant materials involving three different origins: wild genotypes (n = 32), cultivars (n = 62) and genotypes belonging to cultivar × wild progenies (n = 62). As expected, values for fruit size and OC in wild olives were lower than those obtained in cultivated materials, with intermediate values for cultivar × wild progenies. Wild olives showed a remarkably higher C16:0 percentage and tocopherol content in comparison to the cultivars. Contrarily, lower C18:1 percentage, squalene and sterol content were found in the wild genotypes, while no clear differences were found among the different plant materials regarding composition of the tocopherol and phytosterol fractions. Some common highly significant correlations among components of the same chemical family were found in all groups of plant materials. However, some other correlations were specific for one of the groups. The results of the study suggested that the use of wild germplasm in olive breeding programs will not have a negative impact on fatty acid composition, tocopherol content, and tocopherol and phytosterol profiles provided that selection for these compounds is conducted from early generations. Important traits such as tocopherol content could be even improved by using wild parents.

Composition of fatty acids in virgin olive oils from cross breeding segregating populations by gas chromatography separation with flame ionization detection

BACKGROUND

Recent technological advances to improve the quality of virgin olive oil (VOO) have been focused on olive breeding programs by selecting outstanding cultivars and target progenies. Fatty acid (FA) composition, with special emphasis on oleic acid (C18:1) and palmitic acid (C16:0), is one of the most critical quality factors to be evaluated in VOO. For this reason, the profile of FAs is frequently used as a decision tool in olive breeding programs.

RESULTS

A method based on gas chromatography with flame ionization detection (GC-FID) was used to study the influence of genotype on the concentration of ten of the most important FAs in VOOs from target crosses Arbequina × Arbosana, Picual × Koroneiki and Sikitita × Arbosana and their corresponding genitors Arbequina, Arbosana, Koroneiki, Picual and Sikitita. For this purpose, a targeted approach was selected for determination of esterified FAs (EFAs) and non-esterified FAs (NEFAs) in a dual analysis by the same chromatographic method. A Pearson analysis revealed correlations between pairs of FAs, which allowed detecting metabolic connections through desaturation and elongation enzymes. An ANOVA test (with P < 0.01) led to identification of C16:0 EFA, C16:1 EFA and C18:1 EFA and also C16:1 NEFA and C18:0 NEFA as the FAs more influenced by cross breeding. Statistical analysis was carried out by unsupervised analysis using principal component analysis (PCA) and cluster analysis (CA) to look for variability sources.

CONCLUSION

Crosses with a common genitor (Arbequina × Arbosana and Sikitita × Arbosana) were partially overlapped in the PCAs using the profile of FAs. The CA results revealed clear differences between Sikitita × Arbosana and Picual × Koroneiki crosses in the composition of the most significant FAs, while Arbequina × Arbosana was not properly discriminated from the other crosses.