Abstract
Current nutritional rating systems, like the health star rating, help consumers understand the nutritional value of food and were designed in an effort to combat obesity. However, these systems have limitations, especially for edible oils, which vary widely in composition(1). Coupled with the lack of standardisation in ranking edible oils, there has been advocacy for the introduction of different nutritional scores for edible oils. This study aims to develop a simple and easy-to-use nutritional scoring index based on the composition of extra virgin olive oil (EVOO). The composition includes all fatty acid parameters and total polyphenol content, measurable by nuclear magnetic resonance (NMR) spectroscopy, thereby avoiding the need for multiple analytical platforms. The development of an EVOO nutritional score involved: i) establishing a unique consensus dietary reference index (DRIs) for each component and evaluating their impact on human health(2,3); and ii) computing Scoring Reference Values (SRVs) for each component, expressed as grams of component per 100 g of EVOO, based on the assumptions of a daily energy intake of 2000 kcal, with a fat intake of 35% of total caloric intake(2,3), and considering EVOO as the only source of fat. A nutritional score (0–100) was developed based on saturated fat (SFA), trans-unsaturated fat, oleic, linoleic, alpha-linolenic acids, and polyphenols. Components with more substantial effects/evidence on human health were given greater weight in the scoring. The developed index was subsequently applied to evaluate 314 EVOOs that passed the International Olive Oil Council (IOC) quality criteria. These oils were sourced from Australia (n = 94), Greece (n = 54), Italy (n = 54), Spain (n = 69), and Tunisia (n = 43) and analysed using 400 MHz NMR spectroscopy. Nutritional scores for all samples showed a mean of 62.3 (range 13 to 94), with Australian EVOOs exhibiting the highest mean score of 65, followed by Spain, Tunisia, Italy, and Greece. EVOOs were differentiated by their SFA content and the balance between polyunsaturated (PUFA) and monounsaturated fatty acids (MUFA). MUFA and PUFA were typically inversely related, except for two Australian oils that achieved high levels of both. This novel scoring index for EVOOs, grounded in health-related compositional parameters, facilitates the differentiation of EVOOs based on their nutritional value. This enables consumers to make informed choices regarding their oil selection. Given the rising prevalence of obesity and its associated morbidity, this tool is particularly significant. Additionally, the implementation of this nutritional index encourages producers to produce oils with superior nutritional profiles.
