In vitro binding of bile salts by lentil flours, lentil protein concentrates and lentil protein hydrolysates Chockry Barbana a , Anne Claire Boucher b,c , Joyce Irene Boye a, ⁎ a Food Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Blvd. W., St-Hyacinthe, QC, Canada J2S 8E3 b Polytech'Lille-Université Lille1, Avenue Paul Langevin 59655 Villeneuve d'Ascq cedex, France c World Food Program, Via C.G. Viola 68, Parco dei Medici 00148, Rome, Italy abstract article info Article history: Received 15 July 2010 Accepted 31 October 2010 Keywords: Lentil Bile salt binding Flour Protein hydrolysate Protein concentrate The binding capacity of bile salts by lentil flours produced from two varieties, Blaze and Laird and their protein concentrates and hydrolysates were studied. Sodium cholate, sodium deoxycholate, sodium taurocholate, sodium glycocholate and sodium chenodeoxycholate were tested individually, and their binding interactions with the lentil products were analyzed using the Trinity Biotech Bile Acids Kit 450-10 and compared to cholestyramine. All tested samples bound the bile salts investigated, and the amount of bile salts bound (N 70%) was sometimes greater than that bound by cholestyramine. Overall, there were no major differences in the bile salt binding capacities of similar samples prepared from the two varieties of lentil. In vitro digestion of the lentil proteins by pepsin/trypsin/α-chymotrypsin, alcalase/flavourzyme and papain significantly reduced the bile salt binding capacity compared to the undigested samples except in the case of sodium deoxycholate where no significant differences in bile salt binding were observed before and after hydrolysis. Binding of bile salts has been linked to cholesterol reduction, thus, the ability of the lentil products to bind bile salts is of interest as it may suggest that lentils could potentially have cholesterol-reducing properties. Crown Copyright © 2010 Published by Elsevier Ltd. All rights reserved. 1. Introduction Lentil (Lens culinaris), a leguminous plant native to southwest Asia, has been widely consumed in the Middle East and throughout the Mediterranean since prehistoric times (Roy, Boye, & Simpson, 2010). When included in the diet, lentil provides a good source of carbohydrates (e.g., fibre, resistant starch and oligosaccharides), protein (particularly the essential amino acids lysine and leucine), vitamins and minerals (Roy et al., 2010). Regular dietary intake of lentil may be associated with cholesterol-lowering effects and a reduced incidence of colon cancer and type 2 diabetes (Agriculture and Agri-Food Canada, 2006, 2008). Recently, Boye, Roufik, Pesta, and Barbana (2010b) showed that red lentil in vitro tryptic digest possess angiotensin converting enzyme inhibitory activity. Lentil also contains other components such as trypsin inhibitors, α-amylase inhibitors, tannins and phytic acid which were previously considered to be anti- nutritional. Recent research studies, however, suggest that these components may have health-benefiting properties (Roy et al., 2010). With increasing consumer awareness of the possible link between food and health there is pressing need to identify and promote healthy foods which may reduce medical risks linked to various chronic diseases (Murty, Pittaway, & Ball, 2010). Cardiovascular disease, a group of diseases that includes hypertension, atheroscle- rosis, coronary heart disease and stroke, is a major health risk that causes more than 29% of total global deaths (World Health Organization, 2009). It is predicted that, by 2010, cardiovascular disease will be the leading cause of death in developing countries (World Health Organization, 2009). Thus, foods with the potential to reduce cardiovascular disease risk are of considerable interest. Hypercholesterolemia is the presence of a high level of total cholesterol in the bloodstream. Hypercholesterolemia provokes an accumulation of LDL (low-density lipoprotein) cholesterol in the blood vessels, increasing the risk of heart disease and atherosclerosis (World Health Organization, 2009). In some cases, hypercholesterol- emia may be prevented by a healthy diet, exercise and the use of hypolipidemic agents such as bile acid sequestrants (Anderson & Siesel, 1990). Bile acids are acidic steroids that are biosynthesized from cholesterol in the liver and are reabsorbed by the terminal ileum. Thus, disruption of the reabsorption of bile acids through their Food Research International 44 (2011) 174–180 Abbreviations: RLF, red lentil flour; GLF, green lentil flour; RLPC, red lentil protein concentrate; GLPC, green lentil protein concentrate; SC, Sodium cholate; SD, Sodium deoxycholate; ST, Sodium taurocholate; SG, Sodium glycocholate; SCH, Sodium cheno- deoxycholate; GIS, gastrointestinal simulation; AF, alcalase/flavourzyme; P, papain; RLPH- GIS, red lentil protein hydrolysate using gastrointestinal enzymes; GLPH-GIS, green lentil protein hydrolysate using gastrointestinal enzymes; RLPH-AF, red lentil protein hydrolysate using alcalase and flavourzyme; GLPH-AF, green lentil protein hydrolysate using alcalase and flavourzyme; RLPH-P, red lentil protein hydrolysate using papain; GLPH-P, green lentil protein hydrolysate using papain. ⁎ Corresponding author. Tel.: +1 450 768 3232; fax: +1 450 773 8461. E-mail address: Joyce.Boye@agr.gc.ca (J.I. Boye). 0963-9969/$ – see front matter. Crown Copyright © 2010 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.foodres.2010.10.045 Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres