Phillips, K.M., D.M. Ruggio, M. Ashraf-Khorassani, 2005. Phytosterol composition of nuts and seeds commonly consumed in the United States. J. Agric. Food Chem. 53, 9436-9445.
Phytosterols were quantified in nuts and seeds commonly consumed in the United States. Total lipid extracts were subjected to acid hydrolysis and then alkaline saponfication, and free sterols were analyzed as trimethylsilyl derivatives by capillary GC-FID and GC-MS. Δ5-Avenasterol was quantified after alkaline saponification plus direct analysis of the glucoside. Sesame seed and wheat germ had the highest total phytosterol content (400-413 mg/100 g) and Brazil nuts the lowest (95 mg/100 g). Of the products typically consumed as snack foods, pistachio and sunflower kernels were richest in phytosterols (270-289 mg/100 g). β-Sitosterol, Δ5-avenasterol, and campesterol were predominant. Campestanol ranged from 1.0 to 12.7 mg/100 g. Only 13 mg/100 g β-sitosterol was found in pumpkin seed kernel, although total sterol content was high (265 mg/100 g). Phytosterol concentrations were greater than reported in existing food composition databases, probably due to the inclusion of steryl glycosides, which represent a significant portion of total sterols in nuts and seeds.
Drewnowski, A., 2005. Concept of a nutritious food: toward a nutrient density score. Am J Clin Nutr.82:721-32.
The American diet is said to be increasingly energy-rich but nutrient poor. To help improve the nutrient-to-energy ratio, the 2005 Dietary Guidelines for Americans recommend that consumers replace some foods in their diets with more nutrient-dense options. Such dietary guidance presupposes the existence of a nutrient density standard. However, a review of the literature shows that the concept of a nutritious food is not based on any consistent standards or criteria. In many cases, healthful foods are defined by the absence of problematic ingredients—fat, sugar, and sodium—rather than by the presence of any beneficial nutrients they might contain. Past attempts to quantify the nutrient density of foods have been based on a variety of calories-to-nutrient scores, nutrients-per-calorie indexes, and nutrient-to-nutrient ratios. The naturally nutrient rich (NNR) score, which is based on mean percentage daily values (DVs) for 14 nutrients in 2000 kcal food, can be used to assign nutrient density values to foods within and across food groups. Use of the NNR score allows consumers to identify and select nutrient-dense foods while permitting some flexibility where the discretionary calories are concerned. This approach has implications for food labeling, nutritional policy making, and consumer education. The Food and Drug Administration has considered approving nutrient claims based on the ratio of a beneficial nutrient to the food’s energy content, as opposed to a specified minimum amount of a nutrient per serving size. Given the current dietary trends, the nutrient density approach can be a valuable tool for nutrition education and dietary guidance.
Chai, W., M. Liebman, 2005. Oxalate content of legumes, nuts and grain-based flours. Journal of Food Composition and Analysis. 18:723-29.
About 75% of all kidney stones are composed primarily of calcium oxalate and hyperoxaluria is a primary risk factor for this disorder. Since absorbed dietary oxalate can make a significant contribution to urinary oxalate levels, oxalate from legumes, nuts, and different types of grain-based flours was analyzed using both enzymatic and capillary electrophoresis (CE) methods. Total oxalate varied greatly among the legumes tested, ranging from 4 to 80 mg/100 g of cooked weight. The range of total oxalate of the nuts tested was 42-469 mg/100 g. Total oxalate of analyzed flours ranged from 37 to 269 mg/100 g. The overall data suggested that most legumes, nuts, and flours are rich sources of oxalate.
Nash, S.D., M. Westpfal, 2005. Cardiovascular benefits of nuts. American Journal of Cardiology. 963-65.
This review article highlights some of the cardiovascular benefits of nuts. The authors conclude by writing, “Simply stated, at a time of spiraling costs for medical care, public and professional concerns about drug safety, and in an age of fad diets, it is reassuring to have a “nutty alternative.”
Mukuddem-Petersen, J., W. Oosthuizen, J. C. Jerling. 2005. A systematic review of the effects of nuts on blood lipid profiles in humans. J. Nutr. 135; 2082-2089.
The inverse association of nut consumption and risk markers of coronary heart disease (lipids) has sparked the interest of the scientific and lay community. The objective of this study was to conduct a systematic review to investigate the effects of nuts on the lipid profile. Medline and Web of Science databases were searched from the start of the database to August 2004 and supplemented by cross-checking reference lists of relevant publications. Human intervention trials with the objective of investigating independent effects of nuts on lipid concentrations were included. From the literature search, 415 publications were screened and 23 studies were included. These papers received a rating based upon the methodology as it appeared in the publication. No formal statistical analysis was performed due to the large differences in study designs of the dietary intervention trials. The results of 3 almond (50-100 g/d), 2 peanut (35-68 g/d), 1 pecan nut (72 g/d), and 4 walnut (40-84 g/d) studies showed decreases in total cholesterol between 2 and 16% and LDL cholesterol between 2 and 19% compared with subjects consuming control diets. Consumption of macadamia nuts (50-100 g/d) produced less convincing results. In conclusion, consumption of ~50-100 g (~1.5-3.5 servings) of nuts ≥5 times/wk as part of a heart healthy diet with total fat content (high in mono- and/or polyunsaturated fatty acids) of ~35% of energy may significantly decrease total cholesterol and LDL cholesterol in normo- and hyperlipidemic individuals.
Jenkins, D.J.A., C.W.C. Kendall, A. Marchie, D. Faulkner, J.M.W. Wong, R. de Souza, A. Emam, T.L. Parker, E. Vidgen, E.A. Trautwein, K.G Lapsley, R.G. Josse, L.A. Leiter, W. Singer, P.W. Connelly, 2005. Direct comparison of a dietary portfolio of cholesterol-lowering foods with a statin in hypercholesterolemic participants. Am J Clin Nutr. 81:380-387.
Background: 3-Hydroxy-3-methyl-glutaryl-coenzyme A (HMGCoA) reductase inhibitors reduce serum cholesterol and are increasingly advocated in primary prevention to achieve reductions in LDL cholesterol. Newer dietary approaches combining cholesterol lowering foods may offer another option, but these approaches have not been compared directly with statins in the same persons. Objective: The objective was to compare, in the same subjects, the cholesterol-lowering potential of a dietary portfolio with that of a statin. Design: Thirty-four hyperlipidemic participants underwent all three 1-mo treatments in random order as outpatients: a very-low saturated- fat diet (control diet), the same diet plus 20 mg lovastatin (statin diet), and a diet high in plant sterols (1.0 g/1000 kcal), soy protein foods (including soy milks and soy burgers, 21.4 g/1000 kcal), almonds (14 g/1000 kcal), and viscous fibers from oats, barley, psyllium, and the vegetables okra and eggplant (10 g/1000 kcal) (portfolio diets). Fasting blood samples were obtained at 0, 2, and 4 wk. Results: LDL-cholesterol concentrations decreased by 8.5 ± 1.9%, 33.3 ± 1.9%, and 29.6 ± 1.3% after 4 wk of the control, statin, and portfolio diets, respectively. Although the absolute difference between the statin and the portfolio treatments was significant at 4 wk (P = 0.013), 9 participants (26%) achieved their lowest LDL cholesterol concentrations with the portfolio diet. Moreover, the statin (n = 27) and the portfolio (n = 24) diets did not differ significantly (P = 0.288) in their ability to reduce LDL cholesterol below the 3.4-mmol/L primary prevention cutoff. Conclusions: Dietary combinations may not differ in potency from first-generation statins in achieving current lipid goals for primary prevention. They may, therefore, bridge the treatment gap between current therapeutic diets and newer statins.
Maguire, L.S., S.M. O’Sullivan, K. Galvin, T.P. O’Connor, N.M. O’Brien, 2004. Fatty acid profile, tocopherol, squalene and phytosterol content of walnuts, almonds, peanuts, hazelnuts and the macadamia nut. Int J Food Sci Nutr. 55(3):171-178.
Nuts are high in fat but have a fatty acid profile that may be beneficial in relation to risk of coronary heart disease. Nuts also contain other potentially cardioprotective constituents including phytosterols, tocopherols and squalene. In the present study, the total oil content, peroxide value, composition of fatty acids, tocopherols, phytosterols and squalene content were determined in the oil extracted from freshly ground walnuts, almonds, peanuts, hazelnuts and the macadamia nut. The total oil content of the nuts ranged from 37.9 to 59.2%, while the peroxide values ranged from 0.19 to 0.43 meq O2/kg oil. The main monounsaturated fatty acid was oleic acid (C18:1) with substantial levels of palmitoleic acid (C16:1) present in the macadamia nut. The main polyunsaturated fatty acids present were linoleic acid (C18:2) and linolenic acid (C18:3). alpha-Tocopherol was the most prevalent tocopherol except in walnuts. The levels of squalene detected ranged from 9.4 to 186.4 microg/g. beta-Sitosterol was the most abundant sterol, ranging in concentration from 991.2 to 2071.7 microg/g oil. Campesterol and stigmasterol were also present in significant concentrations. Our data indicate that all five nuts are a good source of monounsaturated fatty acid, tocopherols, squalene and phytosterols.
Su, M., M. Venkatachalam, S.S. Teuber, K.H. Roux, S.K. Sathe, 2004. Impact of γ -irradiation and thermal processing on the antigenicity of almond, cashew nut and walnut proteins. J Sci Food Agric. 84:1119–1125.
Whole unprocessed almonds, cashew nuts and walnuts were each subjected to γ -irradiation (1, 5, 10 and 25 kGy) followed by heat processing including autoclaving (121°C, 15 psi for 15 and 30min), dry roasting (138 and 160°C for 30min each, 168 and 177°C for 12 min each), blanching (100°C for 5 and 10 min), oil roasting (191°C, 1min) and microwave heating (500W for 1 and 3 min). Rabbit polyclonal antibodies were raised against each major protein isolated from defatted, but not subjected to γ -irradiation and/or any thermal processing, almond, cashew nut and walnut flours. Immunoreactivity of almond, cashew nut and walnut proteins soluble in borate saline buffer, normalised to 1mg protein ml−1 for all samples, was determined by inhibition enzyme-linked immunosorbent assay (ELISA) and Western blotting. ELISAs and Western blotting experiments indicated that almond, cashew nut and walnut proteins exposed to γ -irradiation alone or followed by various thermal treatments remained antigenically stable.
Dourado, F., A. Barros, M. Mota, M.A. Coimbra, F.M. Gama, 2004. Anatomy and cell wall poly-saccharides of almond (Prunus dulcis D.A. Webb) seeds. J Agric Food Chem.52:1364-1370.
Portuguese almond seed anatomy was analyzed by various staining techniques and light microscopy. The almonds seed coat is thin and structurally complex, with lignified celluosic tissue. The almond kernel cell walls are rich in arabinose (45%) glucose (23%) uronic acids (12%) and xylose (12%).
Su, M., M. Venkatachalam, S.S. Teuber, K.H. Roux, S.K. Sathe, 2004. Impact of γ-irradiation and thermal processing on the antigenicity of almond, cashew nut and walnut proteins. J Sci Food Agric. 84:1119–1125.
Whole unprocessed almonds, cashew nuts and walnuts were each subjected to γ -irradiation (1, 5, 10 and 25 kGy) followed by heat processing including autoclaving (121°C, 15 psi for 15 and 30min), dry roasting (138 and 160°C for 30 min each, 168 and 177◦C for 12 min each), blanching (100°C for 5 and 10 min), oil roasting (191°C, 1min) and microwave heating (500W for 1 and 3min). Rabbit polyclonal antibodies were raised against each major protein isolated from defatted, but not subjected to γ -irradiation and/or any thermal processing, almond, cashew nut and walnut flours. Immunoreactivity of almond, cashew nut and walnut proteins soluble in borate saline buffer, normalised to 1mg protein ml−1 for all samples, was determined by inhibition enzyme-linked immunosorbent assay (ELISA) and Western blotting. ELISAs and Western blotting experiments indicated that almond, cashew nut and walnut proteins exposed to γ -irradiation alone or followed by various thermal treatments remained antigenically stable.
