عنوان مقاله [English]
To study the evaluation of ripening index on qualitative parameters of three olive cultivars ('Zard', 'Local-Roghani' and 'Arbequin') in Roudbar city of Gilan province, an experiment was carried out according to a factorial based on completely randomized design with three replications in 2014. Fruits were harvested at ripening index 3.5, 4 and 5 according to the method proposed by the international olive oil council and after oil extraction, its biochemical and qualitative characteristics were assessed. The results showed significant increases in dry mater, peroxide value, free fatty acid, extinction coefficient at 232 and 270 nm, coupled with significant decline in total phenolics and flavonoids, carotenoid and chlorophyll pigments and antioxidant activity with advancing ripening index. Also, significant differences were observed among the olive cultivars in the all above traits. Total phenolics of olive oil in the 'Local-Roghani' cultivar at ripening index 3.5, 4 and 5 respectively with averages of 941.27, 657.74 and 310.32 mg/kg were more than others. However peroxide value, that is an undesirable trait in the olive oil, was higher in the 'Local-Roghani' cultivar. Although the antioxidant activity among olive cultivars was varied at ripening index 3.5 and 4, but no significant differences were observed at ripening index 5. Overall, the results showed that an increasing in the fruit ripening index was accompanied with decreased in the antioxidant compounds and sensitivity to oxidation of olive oil. Therefore, the oils obtained from the fruits at ripening index 3.5 had greater stability and sustainability.
محمدزاده ج و فخرالدین ف (1384) بررسی تعیین زمان برداشت سه رقم زیتون و تاثیر آن بر کمیت و کیفیت روغن استحصالی در منطقه گرگان. مجله علوم کشاورزی و منابع طبیعی.12(3): 50-45.
نجف آبادی ا و همتی خ (1388) بررسی تعیین زمان برداشت دو رقم زیتون و تاثیر آن بر کیفیت و کمیت روغن در منطقه گرگان. نشریه علوم باغبانی. 24(1): 74-70.
هاشمپور ا، فتوحی قزوینی ر و بخشی د (1388) مقایسه کیفیت روغن زیتون ارقام ایرانی زرد، روغنی و ماری در شهرستان کازرون. مجموعه مقالات ششمین کنگره علوم باغبانی ایران. 1620-1617.
Aguilera MP, Beltran G, Ortega D, Fernandez A, Jimenez A and Uceda M (2005) Characterisation of virgin olive oil of Italian olive cultivars: ‘Frantoio’ and ‘Leccino’, grown in Andalusia. Food Chemistry. 89: 387–391.
Allalout A, Krichene D, Methenni K, Taamalli A, Oueslati I, Daoud D and Zarrouk M (2009) Characterization of virgin olive oil from super intensive Spanish and Greek varieties grown in northern Tunisia. Scientia Horticulturae. 120: 77–83.
Baccouri O, Guerfel M, Baccouri B, Cerretani L, Bendini A, Lercker G, Zarrouk M and Miled DDB (2008) Chemical composition and oxidative stability of Tunisian monovarietal virgin olive oils with regard to fruit ripening. Food Chemistry. 109: 743–754.
Beltran G and Rio C (2004) Influence of harvest date and crop yield on the fatty acid Composition of virgin olive oils from Cv. Picual. Journal of Agricultural and Food Chemistry. 52: 3434-3440.
Brand-Williams W, Cuvelier ME and Berset C (1995) Use of a free radical method to evaluate antioxidant activity. LWT Food Science and Technology. 28: 25–30.
Cioffi G, Pesca M and Caprariis P (2010) Phenolic compounds in olive oil and olive pomace from Cilento (Campania, Italy) and their antioxidant activity. Food Chemistry. 121: 105–111.
Dag A, Kerem Z and Yogev N (2011) Influence of time of harvest and maturity index on olive oil yield and quality. Scientia Horticulturae. 127: 358–366.
EC Regulation 2568 (1991) On the characteristics of olive oil and olive residue oil and on the relevant methods of analysis. Official Journal of the European Communities. 248: 6–34.
Escrich E, Moral R and Grau L (2007) Review molecular mechanisms of the effects of olive oil and other dietary lipids on cancer. Molecular Nutrition and Food Research. 51: 1279–1292.
Gimeno E, Castellote AI, Lamuela-Raventos RM, De La Torre MC and Lopez-Sabater MC (2002) The effects of harvest and extraction methods on the antioxidant content (phenolics, α-tocopherol, and β-carotene) in virgin olive oil. Food Chemistry. 78: 207–211.
González-Santiago M, Martín-Bautista E, Carrero JJ, Fonollá J, Baró L, Bartolomé MV, Gil-Loyzaga P and López-Huertas E (2006) One-month administration of hydroxytyrosol, a phenolic antioxidant present in olive oil, to hyperlipemic rabbits improves blood lipid profile, antioxidant status and reduces atherosclerosis development. Atherosclerosis 188, 35–42.
Gutierrez F, Jimenez B, Ruiz A and Albina MA (1999) Effect of olive ripeness on the oxidative stability of virgin olive oil extracted from the varieties Picual and Hojiblanca and on the different components involved. Journal of Agricultural and Food Chemistry. 47: 121−127.
IOOC (1984) Document no 6. International Olive Oil Council, Madrid.
Issaoui M, Dabbou S, Echbili A, Rjiba I, Gazzah N, Trigui A and Hammami M (2007) Biochemical characterization of some Tunisian virgin olive oils obtained from different cultivars growing in Sfax national collection. Journal of food, Agriculture and Environment. 5: 17-21.
Machado M, Felizardo C, Fernandes-Silva AA, Nunes FM and Barros A (2013) Polyphenolic compounds, antioxidant activity and L-phenylalanine ammonia-lyase activity during ripening of olive cv. “Cobrançosa” under different irrigation regimes. Food Research International. 51: 412–421.
Martinez-Nieto L, Hodaifa G and Lozano-Pena JL (2010) Changes in phenolic compounds and Rancimat stability of olive oils from varieties of olives at different stages of ripeness. Journal of the Science of Food and Agriculture. 90: 2393–2398.
Mickelbart MV and James D (2003) Development of a dry matter maturity index for olive (Olea europaea). New Zealand Journal of Crop and Horticultural Science. 31: 269-276.
Minguez-Mosquera MI, Rejano L, Gandul B, Sanchez AH and Garrido J (1991) Color-pigment correlation in virgin olive oil. Journal of the American Oil Chemists Society. 68: 332–336.
Park YS, Jung ST, Kang SG, Heo BG, Arancibia-Avila P, Toledo F, Drzewiecki J, Namiesnik J and Gorinstein S (2008) Antioxidants and proteins in ethylene-treated kiwifruits. Food Chemistry. 107: 640-648.
Ranalli A, Cabras P, Iannucci E and Content S (2001) Lipochromes, vitamins, aromas and other compounds of virgin olive oil are affected by processing technology. Food chemistry.73: 445–451.
Rayan D, Robards K and Lavee SH (1999) Chang in phenolic content of olive during maturation. International Journal of Food Science and Technology. 34: 265-274.
Roca M and Mínguez-Mosquera MI (2003) Carotenoid levels during the period of growth and ripening in fruits of different olive varieties (Hojiblanca, Picual and Arbequina). Journal of Plant Physiology. 160: 451–459.
Salvador MD, Aranda F and Fregapane G (2001) Influence of fruit ripening on Cornicabra virgin olive oil quality. A study of four successive crop seasons. Food Chemistry. 73: 45–53.
Singleton VL, Orthofer R and Lamuela-Ranventos RM (1999) Analysis of total phenols other oxidation substrates and antioxidants by means of Folin–Ciocalteu reagent. Methods Enzymology. 299: 152–178.
Yousfi K, Cert RM and Garcia JM (2006) Changes in quality and phenolic compounds of virgin olive oils during objectively described fruit maturation. European Food Research and Technology. 223: 117–124.
Youssef NB, Zarrouk W, Carrasco-Pancorbo A, Ouni Y, Segura-Carretero A, Fernandez-Gutierrez A, Daoud D and Zarrouk M (2010) Effect of olive ripeness on chemical properties and phenolic composition of chetoui virgin olive oil. Journal of the Science of Food and Agriculture. 90: 199–204.