Release of Protein, Lipid, and Vitamin E from Almond Seeds during Digestion

Abstract

The evaluation of the bioaccessibility of almond nutrients is incomplete. However, it may have implications for the prevention and management of obesity and cardiovascular disease. This study quantified the release of lipid, protein, and vitamin E from almonds during digestion and determined the role played by cell walls in the bioaccessibility of intracellular nutrients. Natural almonds (NA), blanched almonds (BA), finely ground almonds (FG), and defatted finely ground almonds (DG) were digested in vitro under simulated gastric and gastric followed by duodenal conditions. FG were the most digestible with 39, 45, and 44% of lipid, vitamin E, and protein released after duodenal digestion, respectively. Consistent with longer residence time in the gut, preliminary in vivo studies showed higher percentages of nutrient release, and microscopic examination of digested almond tissue demonstrated cell wall swelling. Bioaccessibility is improved by increased residence time in the gut and is regulated by almond cell walls.

Effects of different forms of hazelnuts on blood lipids and α-tocopherol concentrations in mildly hypercholesterolemic individuals

“…It is hypothesized that the favorable effects of nuts on lipids and lipoproteins are due to their nutrient composition including unsaturated fatty acids and other bioactive substances suggested that the cell wall of whole nuts may limit the bioaccessibility of these nutrients (Ellis et al, 2004;Mandalari et al, 2008;Traoret et al, 2008). Theoretically, the release of these nutrients may be increased by breaking down the cell walls of nuts through grinding or slicing, thereby allowing greater accessibility and imparting greater improvements in blood lipids and lipoproteins.…”

“…Evidence of this concept is derived from in vitro digestion experiments in which lipid, protein and vitamin E from finely ground almonds were found to be more digestible than those from whole almonds (Mandalari et al, 2008). Further, short-term human trials report that whole nut consumption increases fecal fat losses, suggesting that some of the fat passes through the gastrointestinal tract undigested (Ellis et al, 2004;Hollis and Mattes, 2007;Traoret et al, 2008).…”

“…However, recent research has questioned the proportion of nutrients that are readily released from nuts and are thus available for metabolism (Ellis et al, 2004;Berry et al, 2008;Mandalari et al, 2008;Traoret et al, 2008;Cassady et al, 2009). This term has been coined 'bioaccessibility'.…”

Minimal Intestinal Epithelial Cell Toxicity in Response to Short- and Long-Term Food-Relevant Inorganic Nanoparticle Exposure

“…The concentrations used were based on in vitro digestion methods used in previously published studies. [20][21][22][23] The stomach enzyme pepsin (146 U/mL, Sigma-Aldrich) was dissolved in water (pH 2, adjusted with 1N HCl). The small intestinal enzyme mixture pancreatin (2mg/mL, Sigma-Aldrich) was dissolved in water (adjusted to pH 7 with 1M NaHCO3 and HCl).…”

“…LDH activity was assessed using a commercially available kit (LDH Assay Kit, Sigma-Aldrich) according to manufacturer's instructions. Briefly, LDH Assay Substrate Solution, LDH Assay Cofactor Preparation, and LDH Assay Lysis Solution were added to samples and incubated at room temperature for [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] minutes. The absorbance was read on a microplate reader at 490 nm and 690 nm.…”