Composition, quality and oxidative stability of virgin olive oils from some selected wild olives (<i>Olea europaea</i> L. subsp. <i>oleaster</i>)

Abstract

SUMMARYComposition, quality and oxidative stability of virgin olive oils from some selected wild olives (Olea europaea L. subsp. Oleaster).A study on the characterization of virgin olive oils from wild olives (Olea europaea L. subsp. Oleaster) was conducted in order to define new cultivars which are welladapted to the Tunisian environment and yield high quality oils. The study was done during the crop years 2003/04, 2004/05 and 2005/06. The main analytical parameters of the oils were evaluated: fatty acid compositions, chlorophylls, carotenoids, tocopherols and phenolic compounds as well as their relationship with oxidative stability.The fatty acid composition of all the wild olive trees tested produced virgin olive oil which complies with commercial standards, as well as for their appreciable amounts of tocopherols and phenolic compounds. Tocopherol analysis by HPLC revealed the presence of α, β, γ and δ tocopherols in all the studied olive oils. Total tocopherol content was significantly influenced by the varietal factor. It ranged from 310 (SB12) to 780 mg/kg (H3). As for total tocopherols, the amount of each tocopherol varied according to genotype. α tocopherol is the most prominent, whereas β, γ and δ tocopherols are less represented. Results showed a clear influence of total phenols and o-diphenols on virgin olive oil stability (R = 0.905, 0.963 P < 10 -3 , respectively), and a much lower contribution of tocopherols (R = 0.568) and acidic composition (R = 0,563). KEY-WORDS:Oxidative stability -Phenols -Tocopherols -Virgin olive oil -Wild olive. INTRODUCTIONThe olive tree (Olea europaea L.) is a subtropical species typical of the Mediterranean basin where it represents the most important oilproducing crop. Virgin olive oil, due to its use without refining, shows very interesting nutritional and sensorial properties, being one of the pillars of the so-called Mediterranean diet. Its oxidative stability, sensory quality and health properties stem from a prominent and well-balanced chemical composition (Boskou, 1996;Servilli et al., 2004).The increasing popularity of olive oil has been mainly attributed to its high content of oleic acid, which may affect the plasma lipid/lipoprotein profiles and its richness in phenolic compounds acting as natural antioxidants, which may contribute to the prevention of human disease (Visioli et al., 1998;Visioli et al., 2000).Tunisia occupies the fourth place on a worldwide scale in terms of olive oil production (IOOC, 2004). Tunisian olive plantations are spread all over the country in different edapho-climatic conditions and account for about 63 million trees covering 1.6 million hectares. A major effort has been made recently for improving the quality of olive oil produced in Tunisia.At present the Tunisian olive grove is dominated by only two main varieties: Chétoui and Chémlali. The introduction of different virgin olive oil types into the market, with different sensory and chemical Composition, quality and oxidative stability of virgin olive oils from some selected wild ...

1H-NMR fingerprinting to evaluate the stability of olive oil

“…polyphenols and tocopherols. Carelli, 2010;Cercaci, Passalacqua, Poerio, Rodriguez-Estrada, & Lercker, 2007;Gómez-Caravaca et al, 2007;Márquez-Ruiz, Martín-Polvillo, Velasco, & Dobarganes, 2008), peroxide value (CarrascoPancorbo et al, 2007;Di Lecce et al, 2009;Márquez-Ruiz et al, 2008), AOCS method (Diraman, 2008), conjugated dienes (Deiana et al, 2002), conjugated trienes (Hrncirik & Fritsche, 2005), K 232 and K 270 UV indexes (Antolin & Meneses, 2000;Cañizares-Macías, García-Mesa, & Luque De Castro, 2004;Márquez-Ruiz et al, 2008;Platero-López & García-Mesa, 2007), thermogravimetry analyses (Coni, Podestà, & Catone, 2004;García Mesa, Luque de Castro, & Valcárcel, 1993;Gennaro, Piccioli Bocca, Modesti, Masella, & Coni, 1998;Santos, Dos Santos, De Souza, Prasad, & Dos Santos, 2002;Vecchio, Cerretani, Bendini, & Chiavaro, 2009), differential scanning calorimetry analyses (Vecchio et al, 2009), column chromatography and 13 C NMR (Hidalgo, Gómez, Navarro, & Zamora, 2002), high-performance liquid chromatography (Baccouri et al, 2008;Gallina-Toschi, Cerretani, Bendini, Bonoli-Carbognin, & Lercker, 2005;Tena, García-González, & Aparicio, 2009) coupled with UV spectrometry or mass spectrometry (Carrasco-Pancorbo et al, 2007), capillary electrophoresis (Carrasco-Pancorbo et al, 2007;Gallina-Toschi et al, 2005), gas chromatography (Gallina-Toschi et al, 2005;Henna Lu & Tan, 2009), ultrasound-assisted method (Platero-López & García-Mesa, 2007), microwave-assisted method (Cañizares-Macías et al, 2004), ch...…”

Hydrophilic antioxidants of virgin olive oil. Part 2: Biosynthesis and biotransformation of phenolic compounds in virgin olive oil as affected by agronomic and processing factors

“…Baccouri et al [113], while evaluating seven oil samples from seven different oleasters (wild olive trees) under similar agronomic, environmental and technological conditions, observed high genotype effect on the total phenols and o-diphenols amounts with values ranging between 182 and 430 mg expressed as caffeic acid/kg of oil for total phenols and 105-217.6 mg of caffeic acid/kg of oil for o-diphenols. In addition, they noticed high variation of tocopherols content between samples, although a-, b-, g-and d-tocopherols were detected in all oils in different amounts, but maintaining a-tocopherol as major component.…”

“…[112]. Interfertility of cultivated olive tree/wild olive tree and segregation of characters by sexual reproduction make the latter a valuable source of material for cross breeding programs and a material to define new varieties with specific characters as adaptation to given climates and higher quality oils [112,113].…”

EXTRACCIÓN SUPERCRITICA DE ACEITE DE SEMILLAS DE PAPAYA (Carica papaya): COMPOSICIÓN Y PROPIEDADES FISICOQUÍMICAS

“…Por otra parte, la relación de ácidos grasos insaturados/saturados del aceite de semillas de papaya obtenido con CO 2 -SC se ve favorecida principalmente por el contenido de ácido oleico entre 16,15 mg/mL y 165,33 mg/mL (40,65 -71,20%), como en el aceite de semillas de durazno (16) y es cercano al reportado en aceites comerciales como el de canola (64%) (36) y oliva (71,4%-76,8%) (37). Este ácido graso (tipo omega-9) se caracteriza por tener un efecto favorable en la prevención de enfermedades cardiovasculares (38) y es considerado como indicador de alta estabilidad en aceites para frituras (11) ya que es estable frente a la termo-oxidación por la presencia de una sola insaturación (1).…”