Measuring the digestibility of snacks prepared from extruded chickpea and yellow pea

Under-nutrition and related health problems are widespread in India,and food quality, rather than quantity is one of the key issues (1). Many recentmeetings of International organizations have addressed major issues pertainingto the dietary protein intake and its bioavailability.  FAO released a Dietary Protein QualityEvaluation Report in 2011 (2), which was a preface to the 2012 WHO technicalnote on foods for the management of moderate acute malnutrition in children (3).Further to this, an Expert Consultation in October 2013 was held to discussvarious stable isotopic based methods to measure protein quality in humans (4).Protein bioavailability is measured from oro-ileal balance studies. Sinceabsorption occurs only in the small intestine and colonic bacteria can recyclenitrogen, it is impossible to measure it non-invasively in humans. Hence, theuse of intrinsic labeled protein is the best approach to measurebioavailability of indispensable amino acids (IAA) in humans.

Stable isotope labeled plant protein in the food matrix labels the IAAfollowing the preparation and ingestion. Further, their appearance in the bloodgives a unique bioavailability measurement. Use of 13C labeled referenceprotein, such as casein, or 13C-labeled free amino acids along with labeledtest meal, gives a direct measure of the digestion/availability of the proteinunder testing. Therefore, the present study aim is to utilize non-invasive,precise, fast throughput methods to measure digestibility and utilization ofspecific plant nutrients, specifically proteins/ amino acids; focusing onlegume-based food products, i.e., chickpea and yellow pea, as it is critical toevaluate the digestion and absorption of dietary amino acids from these products.This is particularly important for lysine (which is limiting in the targetpopulation’s diets) and methionine (which is potentially limiting in legumeprotein), and important because the target group could have environmentalenteric dysfunction, which could limit digestibility and absorption.

While it may seem that protein digestibility is simply the oro-fecalbalance of ingested protein, fecal protein is largely microbial protein andcompositionally bears no resemblance to the array of dietary amino acidsremaining undigested at the end of the ileum. Accordingly, digestibilitydetermined at the ileal level, as an oro-ileal balance, is critical fordetermining amino acid losses of both dietary and endogenous origin. Howeverthis is virtually impossible to measure non-invasively in healthy humansubjects. Therefore, there is a need to evaluate the term digestibility byusing stable isotopically labeled techniques which employs the use of labeledprotein in food based matrix.