Murley, T., B. Kelly, J. Adhikari, W. Reid, K. Koppel, 2020. A comparison of fatty acid and sensory profiles of raw and roasted pecan cultivars. J Food Sci. 85(9):2665-2672.
Five fatty acids comprise the bulk of the lipid content in pecans: palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. Understanding the profiles of these fatty acids and how they relate to sensory characteristics may offer an explanation for flavor and flavor defects that may exist in certain cultivars of pecans. The objective of this study was to examine and compare fatty acid profiles of three cultivars of pecans (Major, Lakota, and Chetopa), over two crop years, under raw and roasted preparation methods, and understand the fatty acids association with sensory attributes. Percentages of palmitic, stearic, oleic, linoleic, and linolenic acids to total fatty acid content were determined using gas chromatography, and sensory profiles were generated using descriptive sensory analysis. Similar trends were seen across samples, with oleic acid comprising the majority of the total fatty acids and linolenic acid comprising the smallest percentage. There were significant differences in fatty acid content among cultivars and between pecans in the first and second crop year. Few associations were found between the fatty acids and sensory attributes, which suggest that combinations of the fatty acids contribute to certain pleasant or undesirable flavor attributes in the pecans. Subtle differences in fatty acid composition may lead to variation in flavor and flavor intensity or draw attention to or from certain attributes during consumption. Differences in crop year indicated that fatty acid content and therefore flavor are variable year to year. PRACTICAL APPLICATION: This study will help understand how fatty acid content of pecans varies from year to year. This should be taken into account when manufacturing products with pecans as the nutritional content of the product may change as the result.
Bailey, H.M., H.H. Stein, 2020. Raw and roasted pistachio nuts (Pistacia vera L.) are ‘good’ sources of protein based on their digestible indispensable amino acid score as determined in pigs. J Sci Fd Agric. 100(10):3878-3885.
Background: Pistachio nuts may be consumed as raw nuts or as roasted nuts. However, there is limited information about the protein quality of the nuts, and amino acid (AA) digestibility and protein quality have not been reported. Therefore, the objective of this research was to test the hypothesis that raw and roasted pistachio nuts have a digestible indispensable AA score (DIAAS) and a protein digestibility corrected AA score (PDCAAS) greater than 75, thereby qualifying them as a good source of protein. Results: The standardized ileal digestibility (SID) of all indispensable AAs, except arginine and phenylalanine, was less in roasted pistachio nuts than in raw pistachio nuts (P < 0.05). Raw pistachio nuts had a PDCAAS of 73, and roasted pistachio nuts had a PDCAAS of 81, calculated for children 2–5 years, and the limiting AA in the PDCAAS calculation was threonine. The DIAAS values calculated for children older than 3 years, adolescents, and adults was 86 and 83 for raw and roasted pistachio nuts respectively. The limiting AA in both raw and roasted pistachio nuts that determined the DIAAS for this age group was lysine. Conclusion: The results of this research illustrate that raw and roasted pistachio nuts can be considered a good quality protein source with DIAAS greater than 75; however, processing conditions associated with roasting may decrease the digestibility of AAs in pistachio nuts.
Sela, I., A.Y. Meir, A. Brandis, R. Krajmalnik-Brown, L. Zeibich, D. Chang, B. Dirks, G. Tsaban, A. Kaplan, E. Rinott, H. Zelicha, 2020. Wolffia globosa–Mankai Plant-Based Protein Contains Bioactive Vitamin B12 and Is Well Absorbed in Humans. Nutrients. 12, 3067. doi: 10.3390/nu12103067
Abstract: Background: Rare plants that contain corrinoid compounds mostly comprise cobalamin analogues, which may compete with cobalamin (vitamin B12 (B12)) metabolism. We examined the presence of B12 in a cultivated strain of an aquatic plant: Wolffia globosa (Mankai), and predicted functional pathways using gut-bioreactor, and the effects of long-term Mankai consumption as a partial meat substitute, on serum B12 concentrations. Methods: We used microbiological assay, liquid-chromatography/electrospray-ionization-tandem-mass-spectrometry (LC-MS/MS), and anoxic bioreactors for the B12 experiments. We explored the effect of a green Mediterranean/low-meat diet, containing 100 g of frozen Mankai shake/day, on serum B12 levels during the 18-month DIRECT-PLUS (ID:NCT03020186) weight-loss trial, compared with control and Mediterranean diet groups. Results: The B12 content of Mankai was consistent at different seasons (p = 0.76). Several cobalamin congeners (Hydroxocobalamin(OH-B12); 5-deoxyadenosylcobalamin(Ado-B12); methylcobalamin(Me-B12); cyanocobalamin(CN-B12)) were identified in Mankai extracts, whereas no pseudo B12 was detected. A higher abundance of 16S-rRNA gene amplicon sequences associated with a genome containing a KEGG ortholog involved in microbial B12 metabolism were observed, compared with control bioreactors that lacked Mankai. Following the DIRECT-PLUS intervention (n = 294 participants; retention-rate = 89%; baseline B12 = 420.5 ± 187.8 pg/mL), serum B12 increased by 5.2% in control, 9.9% in Mediterranean, and 15.4% in Mankai-containing green Mediterranean/low-meat diets (p = 0.025 between extreme groups). Conclusions: Mankai plant contains bioactive B12 compounds and could serve as a B12 plant-based food source.
McArthur, B., R. Mattes, 2020. Energy extraction from nuts: walnuts, almonds, pistachios. Br J Nutr. 123(4):361-371.
The bioaccessibility of fat has implications for satiety and postprandial lipidemia. The prevailing view holds that the integrity of plant cell wall structure is the primary determinant of energy and nutrient extraction from plant cells as they pass through the gastrointestinal tract. However, comparisons across nuts (walnuts, almonds, pistachios) with varying physical properties do not support this view. In this study, masticated samples of three nuts from healthy adults were exposed to a static model of gastric digestion followed by simulated intestinal digestion. Primary outcomes were particle size and lipid release at each phase of digestion. Walnuts produced a significantly larger particle size post-mastication compared to almonds. Under gastric and intestinal conditions, the particle size was larger for walnuts compared to pistachios and almonds (P<0.05). However, the masticated and digesta particle sizes were not related to the integrity of cell walls nor lipid release. The total lipid release was comparable between nuts after the in vitro intestinal phase (P>0.05). Microstructural examination showed ruptured and fissured cell walls that would allow digestion of cellular contents and this may be governed by internal cellular properties such as oil body state. Furthermore, the cell walls of walnuts tend to rupture rather than separate and as walnut tissue passes through the gastrointestinal track, lipids tend to coalesce reducing digestion efficiency.
Ho, K.-V., A. Roy, S. Foote, P.H. Vo, N. Lall, C.-H. Lin, 2020. Profiling anticancer and antioxidant activities of phenolic compounds present in Black Walnuts (Juglans nigra) using a high-throughput screening approach. Molecules. 25, 4516; doi:10.3390/molecules25194516
Our recent studies have demonstrated multiple health-promoting benefits from black walnut kernels. These biological functions of black walnuts are likely associated with their bioactive constituents. Characterization of phenolic compounds found in black walnut could point out underexplored bioactive activities of black walnut extracts and promote the development of novel applications of black walnut and its by-products. In the present study, we assessed bioactivity profiles of phenolic compounds identified in the kernels of black walnuts using a high-throughput screening (HTS) approach. Black walnut phenolic compounds were evaluated in terms of their total antioxidant capacity, antioxidant response element (ARE) induction, and anticancer activities. The anticancer activities were identified by evaluating the effects of the phenolic compounds on the growth of the tumorigenic alveolar epithelial cells (A549) and non-tumorigenic lung fibroblast cells (MRC-5). Out of 16 phenolic compounds tested, several compounds (penta-O-galloyl-β-d-glucose, epicatechin gallate, quercetin, (–)-epicatechin, rutin, quercetin 3-β-d-glucoside, gallic acid, (+)-catechin, ferulic acid, syringic acid) exerted antioxidant activities that were significantly higher compared to Trolox, which was used as a control. Two phenolic compounds, penta-O-galloyl-β-d-glucose and quercetin 3-β-d-glucoside, exhibited antiproliferative activities against both the tumorigenic alveolar epithelial cells (A549) and non-tumorigenic lung fibroblast cells (MRC-5). The antioxidant activity of black walnut is likely driven not only by penta-O-galloyl-β-d-glucose but also by a combination of multiple phenolic compounds. Our findings suggested that black walnut extracts possibly possess anticancer activities and supported that penta-O-galloyl-β-d-glucose could be a potential bioactive agent for the cosmetic and pharmaceutical industries.
Kumari, S., A.R. Gray, K. Webster, K. Bailey, M. Reid, K.A. Han Kelvin, S.L. Tey, A. Chisholm, R.C. Brown, 2020. Does ‘activating’ nuts affect nutrient bioavailability? Food Chem. 319:126529. doi: 10.1016/j.foodchem.2020.126529. Epub 2020 Feb 29.
Claims in the lay literature suggest soaking nuts enhances mineral bioavailability. Research on legumes and grains indicate soaking reduces phytate levels, however, there is no evidence to support or refute these claims for nuts. We assessed the effects of different soaking regimes on phytate and mineral concentrations of whole and chopped almonds, hazelnuts, peanuts, and walnuts. The treatments were: 1. Raw; 2. soaked for 12 h in salt solution; 3. soaked for 4 h in salt solution; 4. soaked for 12 h in water. Phytate concentrations were analysed using high-performance liquid chromatography (HPLC) and minerals by inductively coupled plasma mass spectrometry (ICP-MS). Differences in phytate concentrations between treated and untreated nuts were small, ranging from -12% to +10%. Overall, soaking resulted in lower mineral concentrations, especially for chopped nuts, and did not improve phytate:mineral molar ratios. This research does not support claims that ‘activating’ nuts results in greater nutrient bioavailability.
Malik, V.S., M. Guasch-Ferre, F.B. Hu, M.K. Townsend, O.A. Zeleznik, A.H. Eliassen, S.S. Tworoger, E.W. Karlson, K.H. Costenbader, A. Ascherio, K.M. Wilson, L.A. Mucci, E.L. Giovannucci, C.S. Fuchs, Y. Bao, 2019. Identification of plasma lipid metabolites associated with nut consumption in US men and women. J Nutr 149:1215–1221.
BACKGROUND: Intake of nuts has been inversely associated with risk of type 2 diabetes and cardiovascular disease, partly through inducing a healthy lipid profile. How nut intake may affect lipid metabolites remains unclear. OBJECTIVE: The aim of this study was to identify the plasma lipid metabolites associated with habitual nut consumption in US men and women. METHODS: We analyzed cross-sectional data from 1099 participants in the Nurses’ Health Study (NHS), NHS II, and Health Professionals Follow-up Study. Metabolic profiling was conducted on plasma by LC-mass spectrometry. Nut intake was estimated from food-frequency questionnaires. We included 144 known lipid metabolites that had CVs ≤25%. Multivariate linear regression was used to assess the associations of nut consumption with individual plasma lipid metabolites. RESULTS: We identified 17 lipid metabolites that were significantly associated with nut intake, based on a 1 serving (28 g)/d increment in multivariate models [false discovery rate (FDR) P value <0.05]. Among these species, 8 were positively associated with nut intake [C24:0 sphingomyelin (SM), C36:3 phosphatidylcholine (PC) plasmalogen-A, C36:2 PC plasmalogen, C24:0 ceramide, C36:1 PC plasmalogen, C22:0 SM, C34:1 PC plasmalogen, and C36:2 phosphatidylethanolamine plasmalogen], with changes in relative metabolite level (expressed in number of SDs on the log scale) ranging from 0.36 to 0.46 for 1 serving/d of nuts. The other 9 metabolites were inversely associated with nut intake with changes in relative metabolite level ranging from -0.34 to -0.44. In stratified analysis, 3 metabolites were positively associated with both peanuts and peanut butter (C24:0 SM, C24:0 ceramide, and C22:0 SM), whereas 6 metabolites were inversely associated with other nuts (FDR P value <0.05). CONCLUSIONS: A panel of lipid metabolites was associated with intake of nuts, which may provide insight into biological mechanisms underlying associations between nuts and cardiometabolic health. Metabolites that were positively associated with intake of nuts may be helpful in identifying potential biomarkers of nut intake.
Swackhamer, C., Z. Zhang, A.Y. Tahab, G.M. Bornhorst, 2019. Fatty acid bioaccessibility and structural breakdown from in vitro digestion of almond particles. Food Funct. 10:5174–5187.
Previous studies have shown that the size of almond particles influences lipid bioaccessibility during digestion. However, the extent of structural breakdown of almond particles during gastric digestion and its impact on lipid bioaccessibility is unclear. In this study, in vitro digestion of almond particles was conducted using a dynamic model (Human Gastric Simulator) and a static model (shaking water bath). Structural breakdown of particles during the gastric phase occurred only in the Human Gastric Simulator, as evidenced by a reduction in particle size (15.89 ± 0.68 mm2 to 12.19 ± 1.29 mm2, p < 0.05). Fatty acid bioaccessibility at the end of the gastric phase was greater in the Human Gastric Simulator than in the shaking water bath (6.55 ± 0.85% vs. 4.54 ± 0.36%, p < 0.01). Results showed that the in vitro model of digestion which included peristaltic contractions (Human Gastric Simulator) led to breakdown of almond particles during gastric digestion which increased fatty acid bioaccessibility.
Muralidharan J, S. Galiè, P. Hernández-Alonso, M. Bulló, J. Salas-Salvadó, 2019. Plant-based fat, dietary patterns rich in vegetable fat and gut microbiota modulation. Front. Nutr. 6:157. doi: 10.3389/fnut.2019.00157.
Diet is advocated as a key factor influencing gut microbiota. Several studies have focused on the effect of different carbohydrates, mainly fiber, on gut microbiota. However, what remains to be elucidated is the impact of a key component of diet that is widely debated upon: dietary fats. This review highlights the importance of understanding the source, quality, and type of fats that could differentially modify the intestinal microbiome. Fats from plant-based sources such as nuts, or vegetable oils have shown positive alterations in gut microbiota biodiversity both in in vivo and in vitro studies. Nuts and other plant-based
fat sources, dietary patterns (e.g., Mediterranean diet) rich in polyunsaturated and monounsaturated fats and, in some cases, polyphenols, and other phytochemicals, have been associated with increased bacterial diversity, as well beneficial butyrate-producing bacteria imparting a positive metabolic influence. It is with this interest, this narrative review brings together evidences on different plant-based fat sources, dietary patterns rich in vegetable fats, and associated changes in gut microbiota.
Keywords: gut microbiota, plant-based fats, nuts, vegetable oils, Mediterranean diet
House, J.D., K. Hill, J. Neufeld, A. Franczyk, M.G. Nosworthy, 2019. Determination of the protein quality of almonds (Prunus dulcis L.) as assessed by in vitro and in vivo methodologies. Food Sci Nutr. 7:2932–2938.
Almonds (Prunus dulcis), such as all nuts, are positioned within the protein foods grouping within the current U.S. Dietary Guidelines. The ability to make claims related to the protein content of almonds, within the United States, requires substantiation via the use of the Protein Digestibility‐Corrected Amino Acid Score (PDCAAS). The present study was designed to provide current estimates of PDCAAS, using both in vivo and in vitro assays, of key almond varietals from the 2017 California harvest. Additionally, historical protein and amino acid composition data on 73 separate analyses, performed from 2000 to 2014, were analyzed. Amino acid analysis confirmed lysine as the first‐limiting amino acid, generating amino acid scores of 0.53, 0.52, 0.49, and 0.56 for Butte, Independence, Monterey, and Nonpareil varietals, respectively. True fecal protein digestibility coefficients ranged from 85.7% to 89.9% yielding PDCAAS values of 44.3–47.8, being highest for Nonpareil. Similar, albeit lower, results were obtained from the in vitro assessment protocol. Analysis of the historical data again positioned lysine as the limiting amino acid and yielded information on the natural variability present within the protein and amino acid profiles of almonds. Comparison of the 2017 AA profile, averaged across almond varietals, to the historical data provided strong evidence of persistence of amino acid composition and indices of protein quality over time.
