A critical review on analytical techniques to detect adulteration of extra virgin olive oil

• Published in: Trends in food science & technology 2019-09, Vol.91, p.391-408
• Main Authors: Meenu, Maninder, Cai, Qianxi, Xu, Baojun
• Format: Article
• Language: English
• Subjects: Adulterants; Adulteration; Analytical methods; Aroma; Calorimetry; Chromatographic techniques; Chromatography; Data interpretation; Deoxyribonucleic acid; Differential scanning calorimetry; Digital imaging; DNA; Edible oils; Extra-virgin olive oil; Flavor; Flavors; Gold; Mathematical analysis; Oils & fats; Olive oil; Olive pomace oil; Organic chemistry; Qualitative analysis; Sample preparation; Vibrational spectroscopy
• ISSN: 0924-2244; 1879-3053
• DOI: 10.1016/j.tifs.2019.07.045

Extra virgin olive oil (EVOO) is acknowledged as a liquid gold. It is cherished for its unique aroma, flavour and health benefits. Due to its high demand and high cost, fraudsters deliberately blend low-cost poor quality edible oil with EVOO to get economic benefits. The consumption of adulterated EVOO leads to health and safety issue of consumers. Thus, the rapid, precise, accurate and up-to-date analytical methods are the prerequisite to detect EVOO adulteration. Various official chemical methods are available for the detection of common adulterants in EVOO. However, these procedures are laborious, time-consuming, employ toxic chemicals and expect sample preparation before analysis. Thus, researchers are extensively exploring rapid, precise and green analytical methods to detect and quantify adulteration in EVOO and the present review is focused on summarizing these analytical methods developed in the past few years. Several techniques, such as chromatographic, spectroscopic, differential scanning calorimetry (DSC), DNA analysis and digital imaging have been employed in this field. The chromatographic techniques are reported to be time-consuming, whereas chemometric analysis is required for data interpretation of vibrational spectroscopic techniques, while, DSC is observed to be a qualitative technique. However, DNA analysis was found to be an efficient technique to detect adulterants in EVOO. The currently used officially methods should be upgraded as they are reported to be less sensitive compared to the latest methods. [Display omitted] •EVOO is frequently adulterated with olive pomace oil and other vegetable oils.•Authentication and control of EVOO adulteration is a crucial subject for the olive oil industry.•Current official methods for quality control should be upgraded.•Vibrational spectroscopy was successfully applied for detection and quantification of EVOO adulteration.•Electronic tongue, DNA analysis and digital imaging are the efficient methods for detection of EVOO adulteration.