Comparison of Oil Content and Fatty Acids Profile of Western Schley, Wichita, and Native Pecan Nuts Cultured in Chihuahua, Mexico

Hindawi Journal of Lipids Volume 2018, Article ID 4781345, 6 pages https://doi.org/10.1155/2018/4781345 Research Article Comparison of Oil Content and Fatty Acids Profile of Western Schley, Wichita, and Native Pecan Nuts Cultured in Chihuahua, Mexico L. R. Rivera-Rangel, K. I. Aguilera-Campos, A. García-Triana, J. G. Ayala-Soto, D. Chavez-Flores, and L. Hernández-Ochoa Facultad de Ciencias Quı́micas, Universidad Autónoma de Chihuahua, Campus Universitario #2, Circuito Universitario, 31125 Chihuahua, CHIH, Mexico Correspondence should be addressed to L. Hernández-Ochoa; Received 26 July 2017; Accepted 21 November 2017; Published 22 January 2018 Academic Editor: Javier S. Perona Copyright © 2018 L. R. Rivera-Rangel et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Two different extraction processes, Soxhlet and ultrasound, were used to obtain the oil extracts of Western Schley, Wichita, and Native pecan nuts cultured in Chihuahua, Mexico. The aspects evaluated in this study were the extraction yield of the processes and fatty acids’ profile of the resulting extracts. Gas chromatography coupled with mass spectrometry (GC-MS) was used to identify and determine the composition percentage of fatty acids present in pecan nuts oils extracted. The results obtained show that higher oil extraction yields were obtained by Soxhlet method with hexane (69.90%) in Wichita varieties. Wichita, Western Schley, and Native pecan nuts from Chihuahua are rich in PUFA (polyunsaturated fatty acids) and MUFA (monounsaturated fatty acids) and have low levels of SFA (saturated fatty acids). The predominant fatty acid present in all pecan nuts oils was linoleic acid followed by oleic acid. Myristic acid, palmitic acid, and linolenic acid were also identified in representative quantities. The results from this study suggest that there are statistically significant differences in the chemical composition of the pecan nuts oils extracted from the varieties cultured in Chihuahua, Mexico, and those cultivated in other regions of the world. 1. Introduction In recent years, a lot of interest has been given to the development of edible oils which are rich in bioactive compounds used in health and nutrition industries. An example of such oils is the one obtained from pecan nuts. Pecans [Carya illinoinensis (Wangenh.) K. Koch] are native from North Mexico and south USA and belong to the Juglandaceae family. Chihuahua, Mexico, offers suitable conditions for the cultivation of high-quality pecan nut varieties. Chihuahua is the world leader in production of pecan nut with 80000 tons cultured in 2015; Delicias district produces 53% of Chihuahua’s pecan nut. Predominantly three varieties of nuts are cultivated in Delicias district: Western Schley, Wichita, and Native nuts, and their areas sown are 84.9%, 15%, and 0.1%, respectively [1, 2]. The pecan nut oil is considered a healthy oil due to the fact that it is a rich source of unsaturated fatty acids (UFA) containing primarily monounsaturated fatty acids (MUFA), a good quantity of polyunsaturated fatty acids (PUFA), and a low content of saturated fatty acid (SFA) [3, 4]. Pecan kernels total lipid content varies from 65% to 75% of total kernel weight. Lipid content reports of Western Schley and Wichita varieties in Australia are 73.08% and 73.45%, respectively, while native nut located in central Mexico is 73.95% [5, 6]. In pecan nut oil, the content of oleic acid (C18:1n-9) is the highest followed by linoleic acid (C18:2n-6), lower concentrations of palmitic acid (C16:0), stearic acid (C18:0), and alfa-linolenic acid (C18:3n-3) and traces of other eight fatty acids as seen in analysis of Tunisiangrown and Australian-grown pecan nuts oils obtained by Soxhlet method with petroleum ether [6, 7]. Western Schley nut oil fatty acid content is 53.38% of oleic acid, 34.24% of linoleic acid, 6.65% of palmitic acid, 2.57% of stearic acid, and 1.74% of alfa-linolenic acid. Fatty acid profile of Wichita nut oil is 57.28% of oleic acid, 31.50 of linoleic acid, 6.56% of palmitic acid, 2.38% of stearic acid, and 1.73% of alfa-linolenic 2 acid. Western Schley and Wichita nut oil determinations were done with southeast Australian-grown pecan nuts, using Soxhlet with petroleum ether as extraction method [6]. Fatty acid composition of native nut oil extracted from central Mexican-grown pecan nuts by Soxhlet method with hexane is 64.55% of oleic acid, 24.40% of linoleic acid, 5.23% of palmitic acid, 2.71% of stearic acid, and 2.21% of alfa-linolenic acid [5]. The intake of oils rich in unsaturated fatty acids is associated with many health benefits. Recent studies have demonstrated that the consumption of MUFA can lower LDL (low-density lipoprotein) cholesterol, protects against coronary heart disease (CHD), regulates the blood pressure, and may have beneficial effects on coagulation factors, inflammation, and endothelial activation [8, 9]. Likewise, the consumption of PUFA has positive effects in reducing the risk of cardiovascular and inflammatory diseases [10]. In addition, PUFA have antithrombotic and antiatherosclerotic properties [11]; they may prevent the development of diseases like arterial hypertension and insulin resistance [12, 13]. Also, PUFA have shown protective effects against diabetic renal disease [14]. Despite the health benefits that can be provided for pecan nuts and their economic importance, the chemical components of pecan nuts cultured in Delicias district, Chihuahua, have not been characterized yet. The objective of this study was to characterize the fatty acid profile by GC/MS of Western Schley, Wichita, and Native pecan nut varieties cultured in Delicias district, Chihuahua, Mexico. 2. Materials and Methods 2.1. Pecan Samples. Pecan nuts were mechanically harvested during fall (October-November) 2015 at Delicias district, Chihuahua. Western Schley, Wichita, and Native cultivars were chosen due to their commercial relevance. Approximately 2 kg of nuts per cultivar was dried to 5–7% of humidity and stored at 4∘ C until the oil extraction process. For analysis, 1 kg of nuts per cultivar was manually cracked and the kernel that included the pellicle was separated from the shell. Kernels were immediately processed. 2.2. Chemicals. HPLC grade solvents (hexane, ethanol, and methanol), boron trifluoride (BF3 ), NaOH, and NaCl were purchased from Sigma Chemical Co. (St. Louis, MO). 2.3. Oil Extraction. 50 g of nuts per variety was minced using a food grinder prior to use. Two extraction methods were considered: ultrasound and Soxhlet. Ultrasound-Assisted Extraction. 50 g of minced nuts per variety was mixed separately with 250 ml of solvent (ethanol or hexane) in a 600 ml beaker. The pecan nut solvent suspension was ultrasonicated for 2 hours using a 50 kHz ultrasonic bath (BRANSON 5 (...truncated)