Comparative Study of Oil Quality and Aroma Profiles from Tunisian Olive Cultivars Growing in Saharian Oasis Using Chemometric Analysis

Abstract

Aroma profile, oxidative stability and quality parameters of virgin olive oil from four cultivars (Chemlali, Chetoui, Koroneiki and Rjim), grown in Rjim Maatoug oasis in southern of Tunisia, were studied for the first time. The olive oil samples were obtained during maturation from a crop season (2012-2013). The results showed the quality parameters, i.e., free fatty acid, UV absorbance at 232 and 270 nm, increases during maturation exceeding the upper limit established by the IOOC norm. Chlorophyll and carotenoid pigments tended to decrease during ripening stages. The trend of oxidative stability, total phenols and O-diphenols exhibited a reduction of antioxidant activity at more advanced stages of maturity. The marks achieved showed that oil quality degradation is due to the great drought of climate: high temperature, high light intensity and low rainfall. Studied aroma profiles of cultivars were also influenced by severe climatic conditions. Twenty-four compounds were characterized, representing 94.8-99.8% of the total volatiles. In all samples, a strong decrease was observed in aldehydes compounds

Characterization of aroma, aroma‐active compounds and fatty acids profiles of cv. Nizip Yaglik oils as affected by three maturity periods of olives

“…Hence, there was a clear decrease in the total content of aroma compounds of oils over the fruit maturity periods. Gargouri et al . also reported a reduction behavior in total volatile compounds of oils obtained from Koroneiki and Rjim cultivars.…”

Pigments in extra virgin olive oils produced in different mediterranean countries in 2014: Near UV-vis spectroscopy versus HPLC-DAD

“…The total amount of carotenoids and chlorophylls is similar to that reported for Chemlali EVOOs produced in 2012-2013 (Gargouri et al, 2016). As observed in Tables 4 and 5, Tunisian Chemlali olive oil samples are characterized by a lutein percentage, over carotenoids, rather high (similar to Spanish EVOOs).…”

Physicochemical Characteristics and Antioxidant Potential of the Greek PDO and PGI Virgin Olive Oils (VOOs)

“…They found α-T content values 186 and 228 mg kg À1 for oils obtained from the first field and 279 and 315.8 mg kg À1 from the second one, respectively. At present, publications regarding the antioxidant composition are available for VOOs coming from Koroneiki olive trees grown in various countries in the Mediterranean basin, such as Italy, [66] Morroco, [67] Tunisia, [68][69][70][71][72][73] and Israel, [74] as well as others such as Iran [75] and Brazil. Anastasopoulos et al [65] measuring the oil from olive fruits harvested during November-January 2005/2006, selected three times randomly from various local olive oil mills in Messinia (Peloponnese) and extracted with the same two-phase decanter, reported an unusually high level of α-T (655.37 mg kg À1 ).…”

“…In 2011 Anastasopoulos et al [42] examining oils from fields in Messinia, following conventional and organic farming for three different sampling periods and two harvesting years (2000 and 2004) (n ¼ 4 Â 3 Â 2) found an average value of 255 mg CA kg À1 for conventional farming and %311 mg CA kg À1 for organic. [68,70,71,73] The lowest one was recorded in a sample collected at full maturation (December) from trees grown in an oasis and subjected to a harsh Saharan climate. The same year, Vekiari et al [40] studying Koroneiki from Rethimnon (Crete) at 500 m above sea level from nonirrigated trees at three different stages of growth on the basis of skin color (green, purple and black) found high level of phenols, that is, min %600 and max %1200 mg GA kg À1 oil.…”