Bamberger, C., A. Rossmeier, K. Lechner, L. Wu, E. Waldmann, S. Fischer, R.G. Stark, J. Altenhofer, K. Henze, K.G. Parhofer, 2018. A walnut-enriched diet affects gut microbiome in healthy Caucasian subjects: A randomized, controlled trial. Nutrients. 10(2). pii: E244. doi: 10.3390/nu10020244.
Regular walnut consumption is associated with better health. We have previously shown that eight weeks of walnut consumption (43 g/day) significantly improves lipids in healthy subjects. In the same study, gut microbiome was evaluated. We included 194 healthy subjects (134 females, 63 ± 7 years, BMI 25.1 ± 4.0 kg/m²) in a randomized, controlled, prospective, cross-over study. Following a nut-free run-in period, subjects were randomized to two diet phases (eight weeks each); 96 subjects first followed a walnut-enriched diet (43 g/day) and then switched to a nut-free diet, while 98 subjects followed the diets in reverse order. While consuming the walnut-enriched diet, subjects were advised to either reduce fat or carbohydrates or both to account for the additional calories. Fecal samples were collected from 135 subjects at the end of the walnut-diet and the control-diet period for microbiome analyses. The 16S rRNA gene sequencing data was clustered with a 97% similarity into Operational Taxonomic Units (OTUs). UniFrac distances were used to determine diversity between groups. Differential abundance was evaluated using the Kruskal-Wallis rank sum test. All analyses were performed using Rhea. Generalized UniFrac distance shows that walnut consumption significantly affects microbiome composition and diversity. Multidimensional scaling (metric and non-metric) indicates dissimilarities of approximately 5% between walnut and control (p = 0.02). The abundance of Ruminococcaceae and Bifidobacteria increased significantly (p < 0.02) while Clostridium sp. cluster XIVa species (Blautia; Anaerostipes) decreased significantly (p < 0.05) during walnut consumption. The effect of walnut consumption on the microbiome only marginally depended on whether subjects replaced fat, carbohydrates or both while on walnuts. Daily intake of 43 g walnuts over eight weeks significantly affects the gut microbiome by enhancing probiotic- and butyric acid-producing species in healthy individuals. Further evaluation is required to establish whether these changes are preserved during longer walnut consumption and how these are linked to the observed changes in lipid metabolism.
Chhabra, G.S., C. Liu, M. Su, M. Venkatachalam, K.H. Roux, S.K. Sathe, 2017. Effects of the maillard reaction on the immunoreactivity of amandin in food matrices. J Food Sci. 82(10):2495-2503.
Amandin is the major storage protein and allergen in almond seeds. Foods, containing almonds, subjected to thermal processing typically experience Maillard browning reaction. The resulting destruction of amino groups, protein glycation, and/or denaturation may alter amandin immunoreactivity. Amandin immunoreactivity of variously processed almond containing foods was therefore the focus of the current investigation. Commercial and laboratory prepared foods, including those likely to have been subjected to Maillard browning, were objectively assessed by determining Hunter L∗,a ∗,b ∗ values. The L∗ values for the tested samples were in the range of 31.75 to 85.28 consistent with Maillard browning. Three murine monoclonal antibodies, 4C10, 4F10, and 2A3, were used to determine the immunoreactivity of the targeted samples using immunoassays (ELISA, Westernblot, dotblot). The tested foods did not exhibit cross-reactivity indicating that the immunoassays were amandin specific. For sandwich ELISAs, ratio (R) of sample immunoreactivity to reference immunoreactivity was calculated. The ranges of R values were 0.67 to 15.19 (4C10), 1.00 to 11.83 (4F10), and 0.77 to 23.30 (2A3). The results of dot blot and Western blot were consistent with those of ELISAs. Results of these investigations demonstrate that amandin is a stable marker protein for almond detection regardless of the degree of amandin denaturation and/or destruction as a consequence of Maillard reaction encountered under the tested processing conditions.
Duong, Q.H., K.D. Clark, K.G. Lapsley, R.B. Pegg. 2017. Determination of myo-inositol phosphates in tree nuts and grain fractions by HPLC–ESI–MS. J. Food Comp. Anal. 59:74-82.
High-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC–ESI–MS) was utilized for the rapid, on-line detection of all six forms of inositol phosphate (InsP) in seven major tree nuts (i.e., cashews, Brazil nuts, macadamias, walnuts, pecans, pistachios, hazelnuts) and three grain components that are allegedly rich in phosphorus (wheat aleurone, rice bran, corn germ). The total InsP levels ranged from 3 to 20 μmol/g in the tree nuts and from 10 to 97 μmol/g in the grain components. While inositol hexakisphosphate was the predominant form in all samples, at least 20% of the InsP molar concentration comprised lower forms of InsPs. In tree nuts, InsPs accounted for 18–59% of the organic phosphorus content and 12–46% of the total phosphorus content. For grain samples, these values ranged from 66–97% and 58–80%, respectively. Significant differences in InsP levels among tree nuts underline the need for further investigation of InsPs in this food group, particularly with regard to different cultivars, growing conditions, and processing conditions. HPLC–ESI–MS offered a sensitive and time-efficient detection approach for InsPs in various complex nut and grain matrices, highlighting its potential application for many other sample types.
Bisignano, C., G. Mandalari, A. Smeriglio, D. Trombetta, M.M. Pizzo, M. Pennisi, M.T. Sciortino. 2017. Almond Skin Extracts Abrogate HSV-1 Replication by Blocking Virus Binding to the Cell. Viruses. 9, 178; doi:10.3390/v9070178.
Theaimofthepresentresearchwastodeterminetheeffectofalmondskinextractsonherpes simplex virus 1 (HSV-1) replication. Drug-resistant strains of HSV frequently develop following therapeutic treatment. Therefore, the discovery of novel anti-HSV drugs deserves great effort. Here, we tested both natural (NS) and blanched (BS) polyphenols-rich almond skin extracts against HSV-1. HPLC analysis showed that the prevalent compounds in NS and BS extracts contributing to their antioxidant activity were quercetin, epicatechin and catechin. Results of cell viability indicated that NS and BS extracts were not toxic to cultured Vero cells. Furthermore, NS extracts were more potent inhibitors of HSV-1 than BS extracts, and this trend was in agreement with different concentrations of flavonoids. The plaque forming assay, Western blot and real-time PCR were used to demonstrate that NS extracts were able to block the production of infectious HSV-1 particles. In addition, the viral binding assay demonstrated that NS extracts inhibited HSV-1 adsorption to Vero cells. Our conclusion is that natural products from almond skin extracts are an extraordinary source of antiviral agents and provide a novel treatment against HSV-1 infections.
Duong, Q.H., K.D. Clark, K.G. Lapsley, R.B. Pegg. 2017. Quantification of inositol phosphates in almond meal and almond brown skins by HPLC/ESI/MS. Food Chem. 229:84-92.
The extraction and measurement of all six forms of inositol phosphates (InsPs) in almond meal and brown skins were improved from existing methods by pH adjustment, supplementation of EDTA, and rapid analysis via anion-exchange high-performance liquid chromatography coupled with electrospray ionization mass spectrometry. The quantity of InsPs in six major almond cultivars ranged from 8 to 12 μmol/g in the meal and 5 to 14 μmol/g in the brown skins. InsP6 was the dominant form, but lower forms still accounted for ∼20% of the total InsPs molar concentration in a majority of the samples. InsPs contributed 32–55% of the organic phosphorus content and 20–38% of the total phosphorus content in the meal. In brown skins, these ranges were 44–77% and 30–52%, respectively. The successful application of this analytical method with almonds demonstrates its potential use for re-examination of the reported phytic acid contents in many other tree nuts, legumes, grains, and complex foods.
Bolling, B.W., 2017. Almond polyphenols: methods of analysis, contribution to food quality, and health promotion. Comprehensive Reviews In Food Science And Food Safety; doi: 10.1111/1541-4337.12260.
Almond is a nutrient-dense tree nut recognized for its favorable lipid profile, vitamin E content, and polyphenols. The objectives of this review were to determine the polyphenols reported in almond, summarize the methods of analysis, and determine the polyphenol contribution to almond quality and health-promoting activity. Approximately 130 different polyphenols have been identified in almond, although not all of these have been quantitated. The mean and 25% to 75% percentile contents reported in literature were 162 mg (67.1 to 257) proanthocyanidins (dimers or larger), 82.1 mg (72.9 to 91.5) hydrolysable tannins, 61.2 mg (13.0 to 93.8) flavonoids (non-isoflavone), 5.5mg(5.2to12) phenolic acids and aldehydes, and 0.7mg (0.5to0.9) isoflavones, stilbenes, and lignans per100g almond. Following solvent extraction of almond, hydrolysis of the residue liberates additional proanthocyanidins, phenolic acids andaldehydes, and total phenols. Blanching and skin removal consistently reduces almond polyphenol content, but blanch water and almond skins retain enough polyphenols to be used as antimicrobial and antioxidant ingredients. Roasting and pasteurization have inconsistent effects on almond polyphenols. Almond polyphenols contribute to shelf life by inhibiting lipid oxidation and providing pigmentation, flavor, astringency, and antimicrobial activity. The health-promoting activity of whole almonds has been widely investigated, but few have considered the contribution of polyphenols. Preclinical studies of polyphenol-rich almond skin or almond extracts suggest putative effects on antioxidant function, detoxification, antiviral activity, anti-inflammatory function, and topical use for inhibiting ultraviolet A damage. Therefore, almond has a diverse polyphenol profile contributing to both its food quality and health-promoting actions.
Grassby, T., G. Mandalari, M. M.-L. Grundy, C.H. Edwards, C. Bisignano, D. Trombetta, A. Smeriglio, S. Chessa, S. Ray, J. Sanderson, S.E. Berry, P.R. Ellis, K.W. Waldron, 2017. In vitro and in vivo modeling of lipid bioaccessibility and digestion from almond muffins: The importance of the cell-wall barrier mechanism. Journal of Functional Foods. 37:263–271.
This study compares in vitro and in vivo models of lipid digestion from almond particles within a complex food matrix (muffins) investigating whether the cell-wall barrier regulates the bioaccessibility of nutrients within this matrix. Muffins containing small (AF) or large (AP) particles of almond were digested in triplicate using an in vitro dynamic gastric model (DGM, 1 h) followed by a static duodenal digestion (8 h). AF muffins had 97.1 ± 1.7% of their lipid digested, whereas AP muffins had 57.6 ± 1.1% digested. In vivo digestion of these muffins by an ileostomy volunteer (0–10 h) gave similar results with 96.5% and 56.5% lipid digested, respectively. The AF muffins produced a higher postprandial triacylglycerol iAUC response (by 61%) than the AP muffins. Microstructural analysis showed that some lipid remained encapsulated within the plant tissue throughout digestion. The cell-wall barrier mechanism is the main factor in regulating lipid bioaccessibility from almond particles.
Chen, C.Y.-O., A. Smith, Y. Liu, P. Du, J.B. Blumberg, J. Garlick, 2017. Photoprotection by pistachio bioactives in a 3-dimensional human skin equivalent tissue model. International Journal of Food Sciences and Nutrition. Doi:10.1080/09637486.2017.1282437.
Reactive oxygen species (ROS) generated during ultraviolet (UV) light exposure can induce skin damage and aging. Antioxidants can provide protection against oxidative injury to skin via “quenching” ROS. Using a validated 3-dimensional (3D) human skin equivalent (HSE) tissue model that closely mimics human skin, we examined whether pistachio antioxidants could protect HSE against UVA-induced damage. Lutein and c-tocopherol are the predominant lipophilic antioxidants in pistachios; treatment with these compounds prior to UVA exposure protected against morphological changes to the epithelial and connective tissue compartments of HSE. Pistachio antioxidants preserved overall skin thickness and organization, as well as fibroblast morphology, in HSE exposed to UVA irradiation. However, this protection was not substantiated by the analysis of the proliferation of keratinocytes and apoptosis of fibroblasts. Additional studies are warranted to elucidate the basis of these discordant results and extend research into the potential role of pistachio bioactives promoting skin health.
Schuster, M.J., J.E. Painter, R. Bernas, J. MacKenzie, 2017. Consumers’ feelings of guilt as a function of snack type. EC Nutrition 7.6:291-297.
This study investigates the association between leading snack foods and consumers’ feelings of guilt and willingness to share. Our hypothesis was that guilt and willingness to share will vary as a function of snack type. We further hypothesized that consumers who choose nutrient-dense snacks, would feel less guilt and increased willingness to share when compared to other less nutrient-dense snack foods. Consumers were given 6 of the leading snack brands. Data was collected on the consumers’ feeling of guilt and willingness to share after reading the label and consuming each item. Results showed that consumers vary in their feeling of guilt and willingness to share as a function of snack type. These variations may be partially explained by the nutrient content and the length and makeup of the ingredients of the snacks. Higher nutrient levels and fewer ingredients may partially explain lower ratings of guilt and greater willingness to share.
Cardoso, B.R., G.B. Silva Duarte, B.Z. Reis, S.M.F. Cozzolino, 2017. Brazil nuts: Nutritional composition, health benefits and safety aspects. Food Res Int. 100(Pt 2):9-18.
Brazil nuts are among the richest selenium food sources, and studies have considered this Amazonian nut as an alternative for selenium supplementation. Besides selenium, Brazil nuts present relevant content of other micronutrients such as magnesium, copper, and zinc. The nutritional composition of nuts, also characterized by adequate fatty acid profile and high content of protein and bioactive compounds, has many health benefits. In the present review, we examine the nutritional composition of Brazil nuts, comparing it with other nuts, and describe the relevance of possible contaminants and metal toxicants observed in this nut for human health. Furthermore, we report different trials available in the literature, which demonstrate positive outcomes such as modulation of the lipid serum profile, enhancement of the antioxidant system and improvement of anti-inflammatory response. These effects have been assessed under different conditions, such as cognitive impairment, dyslipidemia, cancer, and renal failure.
