Glycemic and insulinemic responses in women consuming extruded amaranth (Amaranthus cruentus L)

Abstract

Amaranth is a pseudocereal, the nutritional and functional values of which have attracted much interest recently. Amaranth has become popular among patients with celiac disease because it does not cause allergic reactions in the intestinal mucosa. However, the high prevalence of diabetes mellitus among these patients is well known. This study investigated the starch digestibility of an extruded amaranth product. The digestion behavior was observed by the glycemic and insulinemic responses of 11 women to the amaranth product, in comparison with the responses to a reference food (white bread). The responses of women to amaranth gave rise to a mean glycemic index of 107 and an insulinemic curve that indicated greater capacity to stimulate insulin production. This digestion profile was probably due to the drastic processing that the amaranth grain had been subjected to, which provided suitable conditions for enzyme attack. Because of its fast digestion, such amaranth snacks are recommended for athletes and, when consumed by diabetic patients with celiac disease, should be assessed in a dietary program.

Introduction

Amaranth is the third most important staple crop for pre-Colombian people. Recently, interest in amaranth has increased because of its nutritional and functional values [1], [2], [3]. Amaranth is one of the few cultivated plants from which the leaves are used as a vegetable and the grain as a cereal [1]. Snack foods with good acceptance and high nutritive value have been developed by extrusion cooking of the defatted flour obtained from milling the grain [4]. The extrusion cooking process is based on starch gelatinization and protein denaturation using high pressure and high temperature [5]. As well as its high acceptability [4], such amaranth snack foods also present characteristics such as cholesterol-lowering effects in hypercholesterolemic rabbits [6], protein of high biologic value, and high bioavailability of calcium, zinc, and magnesium [7].

Over the last few years, amaranth has become popular among patients with celiac disease because it does not cause allergic reactions in the intestinal mucosa [8]. However, the high prevalence of diabetes mellitus among these patients, and vice versa, is well known [9], [10]. Therefore, there is a need to study the starch digestion and absorption of amaranth snack foods because the consumption of amaranth products has been increasing among patients with celiac disease.

Several intrinsic and extrinsic food factors are involved in the duration and extent of glycemic and insulinemic responses, such as the free sugar type, starch granule characteristics, food processing conditions, and other food components present that may affect starch digestion and absorption [11], [12], [13]. In 1981, Jenkins et al [14] introduced the concept of the glycemic index, which allows the classification of foods according to the rate of glycemic response in comparison with a reference food [11].

To study the effect of consuming extruded amaranth on physiological response, the glycemic index and insulinemic response among women were determined in relation to a reference food (white bread).