ABSTRACT: The kernel oil content, kernel FA and TAG com- position, kernel moisture content, and kernel weight as well as fruit weight of three almond cultivars (Achaak, Mazetto, and Per- lees) were monitored during the maturation of kernels. Lipid frac- tions of all almond samples were extracted using a mixture of chloroform and methanol. FAME and TAG contained in these fractions were analyzed by GC and HPLC, respectively. The ratio of kernel to fruit weight appears to be a good indicator of almond kernel development. The total lipid content of developing al- mond kernels exhibited a sigmoidal pattern with time, similar to seeds and kernels of other higher plants; the cultivar Achaak showed a higher rate of lipid accumulation. The proportion of oleic acid (0) dominated at the later stage of maturation for all three almond cultivars. Although there was no significant differ- ence in the FA composition for the three cultivars studied, marked differences were observed in their TAG profiles. Ten TAG species identified were LLL, LLO, LnOO, LOO, LOP, PLP, OOO, POO, POP, and SOO, where L represents linoleic acid; Ln, linolenic acid; P, palmitic acid; and S, stearic acid. The dif- ference in the TAG profile can be useful for distinguishing vari- ous cultivars. The oil of Mazetto cultivar kernels exhibited a TAG composition comparable to that of olive oil. Paper no. J10466 in JAOCS 81, 901–905 (October 2004). KEY WORDS: Almond oil, fatty acids, maturation, Prunus amygdalus, triacylglycerol. Nuts of the almond tree (Prunus amygdalus Batsch), which belongs to the Rosaceae family, are among the most popular tree nuts worldwide (1). Almonds constitute an important part of the human diet. They are typically used as snack foods as well as ingredients in a variety of processed foods, especially in bakery and confectionery products. It is a widely grown nut crop in the Mediterranean region and the United States of America. The fruit of this crop is highly valued for its dietetic, cosmetic, and pharmaceutical properties. The origin and specificity of agricultural crops are often used to define their quality and commercial value. This generality applies to al- monds, for which many cultivars are known. The lipid content in almonds ranges from 50 to 60% (w/w) (2). The FA composition has been extensively reported for al- mond cultivars from different geographical origins including Italian (3), American (4), Spanish (5), and Tunisian (6). The major FA in almonds are oleic (18:1), representing 60–70% of the total FA; linoleic (18:2), 14–26%; and α-linolenic (18:3), below 1% (7). However, the TAG composition of al- mond nuts has scarcely been reported (8). Recently, the TAG composition of almond kernel oil from 19 cultivars was re- ported, and the cultivars were classified by means of princi- pal component analysis (9). The TAG compositions of almond oil from different cultivars were found to be similar. How- ever, the evolution of FA and TAG composition during matura- tion of the almond kernels is not known. Thus, the objective of this work was to identify and compare the FA and TAG composition of almond oils from three cultivars—Tunisian (Achaak), American (Perlees), and Italian (Mazetto)—during different stages of almond kernel maturation. EXPERIMENTAL PROCEDURES Almond kernels and dry matter content. Almond kernels were collected from Tunisian (Achaak), American (Perlees), and Italian (Mazetto), cultivars grown in the experimental plots of Groupement Obligatoire des Viticulteurs et Producteurs de Fruits (GOVPF) (Tunis, Tunisia). Nuts were harvested every week, starting at 40 d after flowering, for 25 wk. The nuts and kernels were milled separately with a universal cutting mill (Laval Lab Inc., Quebec City, Canada) and weighed, and their dry matter content was then determined after vacuum oven drying at 60°C for 72 h. Lipid extraction, FA and TAG analyses. Lipids were ex- tracted from almond powder with 1:1 (vol/vol) chloro- form/methanol by the Soxhlet method (10). The lipid content was determined by the method of Folch et al. (11). The FA analysis was carried out by converting FA into their methyl esters. FAME were recovered using the procedure of Metcalfe et al. (12). They were separated on a Supelco SP2380 capil- lary column (30 m length; 0.25 mm i.d.; 0.20 mm film thick- ness) of fused silica (Bellefonte, PA) and quantified by using a gas chromatograph (Model 5890A; Hewlett-Packard, Palo Alto, CA) equipped with an FID. The carrier gas was nitro- gen. The injector and detector temperatures were maintained at 230 and 250°C, respectively, whereas the column tempera- ture was maintained at 220°C. FA were identified by compar- ison with known standards. TAG were analyzed by using a high-performance liquid chromatograph (HPLC) equipped with an RP18 stainless-steel column (250 mm length × 4.6 *To whom correspondence should be addressed. E-mail: khaled.belkacemi@sga.ulaval.ca Kernel Fatty Acid and Triacylglycerol Composition for Three Almond Cultivars During Maturation Ammar Cherif a , Khaled Sebei a , Sadok Boukhchina a , Habib Kallel a , Khaled Belkacemi b, *, and Joseph Arul c a Laboratoire de Biochimie des Lipides, Faculté des Sciences de Tunis, Campus Universitaire, 2094 Elmanar II, Tunisie, and Departments of b Soil Science and Agri-Food Engineering and c Food Science and Nutrition, Université Laval, Sainte-Foy, Québec, Canada, G1K 7P4 Copyright © 2004 by AOCS Press 901 JAOCS, Vol. 81, no. 10 (2004)