title: Update on the healthful lipid constituents of commercially important tree nuts.
abstract: Uncharacteristic of most whole foods, the major component of tree nuts is lipid; surprisingly, information on the lipid constituents in tree nuts has been sporadic and, for the most part, not well reported. Most published papers focus on only one nut type, or those that report a cultivar lack a quality control program, thus making data comparisons difficult. The present study was designed to quantify the healthful lipid constituents of 10 different types of commercially important tree nuts (i.e., almonds, black walnuts, Brazil nuts, cashews, English walnuts, hazelnuts, macadamias, pecans, pine nuts, and pistachios) according to standardized, validated methods. The total lipid content of each nut type ranged from 44.4 ± 1.9% for cashews to 77.1 ± 1.7% for macadamias. As expected, the major fatty acids present in the tree nuts were unsaturated: oleic (18:1 ω9) and linoleic (18:2 ω6) acids. A majority of the lipid extracts contained <10% saturated fatty acids with the exceptions of Brazil nuts (24.5%), cashews (20.9%), macadamias (17.1%), and pistachios (13.3%). The total tocopherol (T) content ranged from 1.60 ± 1.27 mg/100 g nutmeat in macadamias to 32.99 ± 0.78 in black walnuts. The predominant T isomers in the nut types were α- and γ-T. Tocotrienols were also detected, but only in 6 of the 10 nut types (i.e., Brazil nut, cashews, English walnuts, macadamias, pine nuts, and pistachios). In most cases, total phytosterol contents were greater in the present study than reported in peer-reviewed journal papers and the USDA National Nutrient Database for Standard Reference, which is attributed to total lipid extraction and the inclusion of steryl glucosides in the analysis; the levels were highest for pistachios (301.8 ± 15.4 mg/100 g nutmeat) and pine nuts (271.7 ± 9.1 mg/100 g nutmeat). Minor sterols were also quantified and identified using GC-FID and GC-MS techniques.
authors: Department of Food Science and Technology, College of Agricultural and Environmental Sciences, The University of Georgia, 100 Cedar Street, Athens, Georgia 30602-2610, United States.
authors: Katherine S
authors: KS
authors: Robbins
authors: Eui-Cheol
authors: EC
authors: Shin
authors: Robert L
authors: RL
authors: Shewfelt
authors: Ronald R
authors: RR
authors: Eitenmiller
authors: Ronald B
authors: RB
authors: Pegg
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005638:Fruit / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D008055:Lipids / Q000032:analysis*; D009754:Nuts / Q000737:chemistry*; D014197:Trees / Q000737:chemistry*
chemical_list: D008055:Lipids