Amino acid profile of raw and extruded blends of African yam bean (Sphenostylis stenocarpa) and cassava flour

Abstract

The main purpose of this work is to improve the low protein content of cassava based products. African yam bean (AYB) (Sphenostylis stenocarpa) seeds and cassava (Manihot exculenta, c) tubers were processed into flours. Extrusion runs were conducted using different ratios of feed blends in a single screw extruder (0.54:99.46; 20:80; 50:50; 80:20; 99.46:0.54) cassava flour/AYB flour. The raw and extruded products were subjected to amino acid analysis. All the amino acids in the raw samples appeared in the extruded products and were proportionally increased as the percentage of AYB increased. The results of the amino acid profile of cassava flour were generally lower except for arginine and glutamic acid, the highest level of loss for AYB was obtained in lysine (62.4%), followed by glycine (47.43%) and aspartic acid (44.96%). Leucine had the lowest percentage loss of 14.14%. The results indicated that extrusion cooking altered the amino acid profile of the extrudates and that blending increased the nutritional value of the products.

Effect of high-temperature, short-time cooking conditions on in vitro protein digestibility, enzyme inhibitor activity and amino acid profile of selected legume grains

“…The combination of high temperature and pressure plus mechanical shear involved in HTST extrusion have the capacity to physically deform proteins by changing their secondary and tertiary structure (Avil es-Gaxiola et al, 2018), thus deactivating enzyme inhibitors. Extrusion of African yam beans at 120 C significantly reduced the concentration of all amino acids with highest and least losses recorded for lysine (62.40%) and leucine (14.4%), respectively (Omeire, 2012). Similarly, significant reduction in essential amino acids for soy flour, sweet potato flour, sweet potato-soy flour blends (80:20) and bambara groundnut-sorghum at extrusion temperature ranging from 100 C to 130 C have also been documented (Iwe et al, 2001;Jiddere and Filli, 2015).…”

“…Few studies exploring the effect of HTST extrusion cooking and extrusion cooking temperatures on chemical composition of sole African yam beans (Sphenostylis stenocarpa), Bambara groundnut (Vigna subterranean) and Pigeon pea (Cajanus cajan) flours exist (Okafor et al, 2014;Okpala et al, 2016;Omeire, 2012). The choice of extrusion conditions i.e.…”

African Yam Bean the Choice for Climate Change Resilience: Need for Conservation and Policy

“…The amino acid (lysine and methionine) has been reported to be higher than those of pigeon pea, cowpea, and bambara groundnut (Uguru and Madukaife 2001). Omeire (2012), noted that the amino acid (g 100 À1 g) profile of AYB comprised of lysine (6.1), histidine (3.1), arginine (6.5), aspartic acid (9.1), glycine (3.9), alanine (4.1), valine (5.0), and phenylalanine (5.1) (Fig. 5).…”

Evaluation of the Genetic Diversity of African Yam Bean (Sphenostylis stenocarpa (Hoechst. ex. A Rich.) Harms.) Using Seed Protein Marker

“…African yam bean is an "Orphan Crop" highly nutritious and has been listed to be among the underutilized legumes despite its immense nutritional advantages in human diets [6,7]. African yam bean has been reported as a good source of essential amino acids including cysteine, lysine, methionine, phenylalanine and Proline [10]. It is predominantly grown by the older, local farmers and leaving the bulk of the genetic resources of this crop in the hands of these farmers threatens its survival [7].…”