Grasas y Aceites, Vol 64, No 1 (2013)

Quality characteristics and microbiological safety evaluation of oils extracted from gamma irradiated almond (Prunus dulcis Mill.) seeds

I. A. Bhatti
Department of Chemistry and Biochemistry, University of Agriculture, Pakistan

M. Iqbal
Department of Chemistry and Biochemistry, University of Agriculture, Pakistan

F. Anwar
Department of Chemistry, University of Sargodha, Pakistan

S. A. Shahid
Department of Physics, University of Agriculture, Pakistan

M. Shahid
Department of Chemistry and Biochemistry, University of Agriculture, Pakistan


The physicochemical attributes and microbial decontamination of oils extracted from gamma-irradiated almond (Mission and Price varieties) seeds, to the absorbed doses of 2-10 kGy, have been evaluated. Gamma irradiation exerted no considerable effect on the proximate seed composition. The physicochemical properties such as density and refractive index of the oils, extracted from gammairradieted seeds, were almost unaffected; the iodine value decreased while saponification value, unsaponifiable matter and free fatty acids increased. The oxidative status and tocopherol content of almond oils were negatively affected while the fatty acid profile slightly changed due to irradiation stress. Interestingly, these effects on the oil quality attributes were more pronounced at higher irradiation doses (> 6 kGy). Besides, microbial contamination was completely eliminated in the oils irradiated to an absorbed dose of 6.0 kGy. It could be concluded from the present findings that irradiation has a considerably positive or negative effect on some attributes of the almond oil. Therefore, an appropriate magnitude of gamma irradiation should be exercised to treat almond seeds in order to retain maximum nutritive benefits.


Absorbed doses; Fatty acids; Gamma irradiation; Microbial decontamination; Oxidative stability; Proximate composition; Tocopherols

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Azim AMN, Shireen EAH, Gammaa AMO. 2009. Effect of gamma irradiation on the physico-chemical characteristics of ground nut (Arachis hypogaea). Aust. J. Basic Appl. Sci. 3, 2856–2860.

Agatemor C. 2006. Studies of selected physicochemical properties of fluted pumpkin (Telfairia occidentalis Hook F) seed oil and tropical almond (Terminalia catappia L.) seed oil. Pak. J. Nutr. 5, 306–307.

Ahmad Z. 2010. The uses and properties of almond oil. Complementary Ther. Clin. Pract. 16, 10–12. PMid:20129403

Al-Bachir M. 2004. Effect of gamma irradiation on fungal load, chemical and sensorycharacteristics of walnuts (Juglans regia L.). J. Stored Prod. Res. 40, 355-362.

Alighourchi H. Barzegar M. Abbasi S. 2008. Effect ofgamma irradiation on the stability of anthocyanins and shelf-life of various pomegranate juices. Food Chem. 110, 1036–1040.

Anjum F, Anwar F, Jamil A, Iqbal M. 2006. Microwave roasting effects on the physico-chemical composition and oxidative stability of sunflower seed oil. J. Am. Oil Chem. Soc. 83, 777-784.

AOAC. 1990. Official methods of analysis of the Association of Official Analytical Chemists. 15th Edn., Association of Analytical Chemists, Arlington, VA, USA, Method 954.01.

Arici M, Colak FA, Gecgel U. 2007. Effect of gamma radiation on microbiological and oil properties of black cumin (Nigella sativa L.). Grasas Aceites. 58, 339-343.

Badr HM. 2006. Effect of gamma radiation and cold storage on chemical and organoleptic properties and microbiological status of liquid egg white and yolk. Food Chem. 97, 285-293.

Barros L, Barreira JCM., Grangeia C, Batista C, Cadavez VAP, Ferreira IC. 2011. Beef burger patties incorporated with Boletus edulis extracts: Lipid peroxidation inhibition effects. Eur. J. Lipid Sci. Technol. 113, 737–743.

Benedito J, Garcıa-Perez JV, Carmen DM, Mulet A. 2007. Rapid evaluation of frying oil degradation using ultrasonic technology. Food Res. Int. 40, 406-414.

Bela PS, Egeaa I, Romojaroa F, Concepcio M, Madrid M. 2008. Sensorial and chemical quality of electron beam irradiated almonds (Prunus amygdalus). Lebensm-Wiss-Technol. 41, 442-449.

Bhatti IA, Ashraf S, Shahid M, Asi MR, Mehboob S. 2010. Quality index of oils extracted from gamma-irradiated peanuts (Arachis hypogaea L.) of the golden and bari varieties. Appl. Radiation. Isot. 68, 2197–2201. PMid:20615718

Boonchoo T, Jitareerat P, Photchanachai S, Chinaphuti A. 2005. Effect of gamma irradiation on Aspergillus flavus and brown rice quality during storage. In: International Symposium ''New Frontier of Irradiated Food and Non-Food Products'', September 22–23, 2005, KMUTT, Bangkok, Thailand ( .

Braghini R, Pozzi CR, Aquino S, Rocha LO, Correa B. 2009. Effects of gamma radiation on the fungus Alternaria alternata in artificially inoculated cereal samples. Appl. Radiat. Isot. 67, 1622–1628. PMid:19375339

Brewer MS. 2009. Irradiation effects on meat flavor: A review. Meat Sci. 81, 1–14. PMid:22063956

Chen CY, Milbury PE, Lapsley K, Blumberg JB. 2005. Flavonoids from almond skins are bioavailable and act synergistically with vitamins C and E to enhance hamster and human LDL resistance to oxidation. J. Nutr. 135, 1366–1373. PMid:15930439

Cordeiro V, Monteiro A. 2001. Almond growing in Trasos- Montes region (Portugal). Acta Hortic. 591, 161- 165.

da Trindade RA, Mancini-Filho J, Villavicencio ALCH, 2009. Effects of natural antioxidants on the lipid profile of electron beam-irradiated beef burgers. Eur. J. Lipid. Sci. Technol. 111, 1161-1168.

Deiana M, Rosa A, Cao CFQ, Pirisi FM, Bandino G, Dessı MA. 2002. Novel approach to study oxidative stability of extra virgin olive oils: importance of alphatocopherol concentration. J. Agric. Food Chem. 50, 4342-4346. PMid:12105968

Ehlermann DAE. 2009. The RADURA-terminology and food irradiation. Food Control. 20, 526-528.

Esfahlan AJ, Jamei R, Esfahlan RJ. 2010. The importance of almond (Prunus amygdalus L.) and its by-products. Food Chem. 120, 349-360.

Evren G, Gulden O. 2008. The effect of food irradiation on quality of pine nut kernels. Rad. Phy. Chem. 77, 365-369.

Galvin K, Morissey PA, Buckley DJ. 1998. Effect of dietary a-tocopherol supplementation and gammairradiation on tocopherol retention and lipid oxidation in cooked minced chicken. Food Chem. 62, 185-190.

Gimeno E, Castellote AI, Lamuela-Raventos RM, Torre MC, Lopez-Sabater MC. 2000. Rapid determination of vitamin E in vegetable oils by reversed-phase highperformance liquid chromatography. J. Chromatogr. A. 881, 251-254.

Graham JA, Panozzo JF, Lim PC, Brouwer JB. 2002. Effects of gamma irradiation on physical and chemical properties of chickpeas (Cicer arietinum). J. Sci. Food. Agric. 82, 1599-1605.

IUPAC. International Union of Pure and Applied Chemistry,1987. Standard Methods for the Analysis of Oils, Fats and Derivatives, 7th rev. enlarged edn., edited by C. Paquot and A. Hautfenne, Blackwell Scientific, London.

ISO. 1977. Oilseed Residues Determination of Total Ash, International Organization for Standardization (ISO), Geneva, Switzerland. Standard No. 749.

Hampson JW, Fox JB, Lakritz L. 1996. Thayer DW, effect of low dose gamma radiation on lipids in five different meats. Meat Sci. 42, 271-276.

Hassanein MM, El-Shami SM, Hassan El-Mallah M. 2003. Changes occurring in vegetable oils composition due to microwave heating. Grasas Aceites. 54, 343-349.

Jalili M, Jinap S, Noranizan A. 2010. Effect of gamma radiation on reduction of mycotoxins in black. Food Control. 21, 1388-1393.

Kodad O, Estopanan G, Juan T, Mamouni A, Socias I Company R. 2011. Tocopherol concentration in almond oil: Genetic variation and environmental effects under warm conditions. J. Agric. Food Chem. 59, 6137-6141. PMid:21524140

Lakritz L, Thayer DW. 1994. Effect of gamma radiation of total tocopherols in fresh chicken breasts muscle. Meat Sci. 37, 439-448.

Lakritz L, Fox JB, Hampson J, Richardson R. 1995. Effect of gamma radiation on levels of a-tocopherol in red meats and turkey. Meat Sci. 41, 261-271.

Lalas S, Gortzi O, Tsaknis J, Sflomos K. 2007. Irradiation effect on oxidative condition and tocopherol content of vegetable oils. Int. J. Mol. Sci. 8, 533-540.

Martins M, Tenreiro R, Oliveira MM. 2003. Genetic relatedness of Portuguese almond cultivars assessed by RAPD and ISSR markers. Plant Cell Reports, 22, 71-78. PMid:12827440

Mexis SF, Kontominas MG. 2009. Effect of ?-radiation on physiochemical and sensory properties of walnuts (Juglans regia L.). Eur. Food Res. Technol. 228, 823–831.

Milbury PE, Chen CY, Dolnikowski GG, Blumberg JB. 2006. Determination of flavonoids and phenolics and their distribution in almonds. J. Agric. Food Chem. 54, 5027-5033. PMid:16819912

Moure A, Pazos M, Medina I, Dominguez H, Parajo JC. 2007. Antioxidant activity of extracts produced by solvent extraction of almond shells acid hydrolysates. Food Chem. 101, 193-201.

Muik B, Lendl B, Molina-Dıaz A, Ayora-Canada MJ. 2005. Direct monitoring of lipid oxidation in edible oils by fourier transform raman spectroscopy. Chem. Phy. Lipids. 134, 173-182. PMid:15784235

Prakash A, Lim FT, Duong C, Caporaso F, Foley D. 2010. The effects of ionizing irradiation on Salmonella inoculated on almonds and changes in sensory properties. Rad. Phys. Chem. 79, 502-506.

Richardsa A, Wijesunderaa C, Salisbury P. 2005. Evaluation of oxidative stability of canola oils by headspace analysis. J. Am. Oil Chem. Soc. 82, 869-874.

Rohman A, Che Man YB, Ismail A, Hashim P. 2011. Monitoring the oxidative stability of virgin coconut oil during oven test using chemical indexes and FTIR spectroscopy. Int. Food. Res. J. 18, 303-310.

Siddhuraju P, Makkar HPS, Becker K. 2002. The effect of ionising radiation on anti nutritional factors and the nutritional value of plant materials with reference to human and animal food. Food Chem. 78, 187–205.

Song HP, Kim B, Yun H, Kim DH, Kim YJ, Jo C. 2009. Inactivation of 3-strain cocktail pathogens inoculated into Bajirak jeotkal, salted, seasoned, and fermented short-necked clam (Tapes pilippinarum), by gamma and electron beam irradiation. Food Control. 20, 580-584.

Steel RGD, Torrie JH. 1992. Prienciples and procedures of Statistics. 2nd Ed., McGraw Hill Book Co. Inc., Singapore.

Suhaj M, Racova J, Polovka M, Brezova V. 2006. Effect of gamma-irradiation on antioxidant activity of blackpepper (Piper nigrum L.). Food Chem. 97, 696-704.

Thomas J, Senthilkumar RS, Kumar RR, Mandal AKA, Muraleedharan N. 2008. Induction of gamma-irradiation for decontamination and to increase the storage stability of black teas. Food Chem. 106, 180-184.

Uquiche E, Jerez M, Ortız J. 2008. Effect of pretreatment with microwaves on mechanical extraction yield and quality of vegetable oil from Chilean hazelnuts (Gevuina avellana Mol). Innov. Food Sci. Emerging Technol. 9, 495-500.

Yaqoob N, Ijaz AB, Farooq A, Muhammad RA. 2010. Oil quality characteristics of irradiated sunflower and maiz seed. Eur. J. Lipid Sci. Technol. 112, 488-495.

Yusof N, Ramli RAA, Ali F. 2007. Chemical, sensory and microbiological changes of gamma irradiated coconut cream powder. Radiat. Phys. Chem. 76, 1882–1884.

Wijeratne SSK, Abou-zaid MM, Shahidi F. 2006. Antioxidant polyphenols in almond and its coproducts. J. Agric. Food Chem. 54, 312-318. PMid:16417285

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