Quinoa and amaranth: multi-purpose agro-industrial crops

Abstract

Studies were conducted in 2018 with two multi-purpose agro-industrial crops [quinoa (Chenopodium quinoa Willd.) and amaranth (Amaranthus sp.)] to characterize its chemical composition. Limited information is available on the nutritional value of quinoa grown in a tropical environment. The objective of this research was to developed an amino acids profile, determined crude protein, by two nitrogen procedures (Kjeldahl and Combustion), dietary fiber, total fat, starch and mineral (calcium, magnesium, phosphorous, potassium, iron and zinc) concentrations on 3-wk old leaves and mature seeds of three quinoa accessions [Ames 13746 (Pison), Ames 13748 (Copacabana) and Ames 13745 (Kaslaea)]. Compositional analysis was completed using AOAC, AACCI, and AOCS official methods. Leaves samples were dried in a forced air oven at 65° C for 72 hours, ground in a Wiley mill. Seeds at physiological maturity (15-wks) were harvested, dried and ground for analysis. Data were analyzed using SAS, and means were separated using Tukey’s test, when significant differences were found. Lysine was higher than most of the staple grains. There was no significant (P >0.05) difference between Pison, Copacabana and Kaslaea for crude protein of leaves and seeds in both N procedures. However, there was a significant difference (P <0.05) between N procedures. Crude protein percentages were higher using the Combustion method with mean percentage of 33.3 and 16.6 %, leaves and seed respectively. Insoluble dietary fiber (IDF), total dietary fiber (TDF) percentage in the leaves differed significantly (P >0.05) among quinoa accessions, whereas soluble dietary fiber (SDF) was similar. Seeds of quinoa did not differ significantly (P >0.05) in percentage IDF, SDF and TDF, nor in total fat and total starch. Calcium (Ca) and phosphorous (P) concentrations were different (P <0.05) among accessions, but not for magnesium (Mg), iron (Fe), potassium (K) and zinc (Zn), but among accessions seed there was no significant (P >0.05) difference. This result shows high nutritional properties (crude protein and minerals) of quinoa accessions, with Kaslaea exhibiting higher total dietary fiber in their leaves. For the second study, chemical components were determined on the leaves and seeds of four amaranth varieties. Information is lacking on the chemical composition of leaves and seed of A. cruentus (Juana, Aurelia, Elena) and A viridis (Callaloo) in Puerto Rico. The objective of this study was to develop an amino acids profile, and determine crude protein, by two nitrogen procedures (Kjeldahl and Combustion) dietary fiber, total fat, starch and mineral (calcium, magnesium, phosphorous, potassium, iron and zinc) concentrations on 3-wk old leaves and mature seeds of field grown A. cruentus (Juana, Aurelia, Elena) and A viridis (Callaloo). Compositional analysis was completed using AOAC, AACCI, and AOCS official methods. Harvested leaves were dried in a forced air oven at 65° C for 72 hours, and ground in a Wiley mill. Seeds at physiological maturity (15-wks) were harvested, dried and ground for analysis. Data were analyzed using SAS, and when means were significant were separated using Tukey’s test. Lysine content of amaranth species was higher than common cereals. There were significant differences (P >0.05) in crude protein (CP) on leaves for both nitrogen procedures. But among amaranth seeds, there was no significant difference (P >0.05). Combustion presented the higher CP percentage (22 %) and (19 %) leaves and seed respectively. Among amaranth leaves, there were significant differences (P >0.05) in IDF and TDF, while amaranth seeds differed (P >0.05) for IDF, SDF and TDF. While total fat and starch in the seeds were not different (P >0.05). Calcium, Mg, and P concentrations differed in their leaves (P >0.05), but Fe, K, and Zn did not. Among amaranth seeds, there was a significant difference (P >0.05) for Ca, Mg, Fe, and P. This study demonstrates that amaranths are an excellent source of nutrients, with Elena and Aurelia having higher CP percentage in their leaves.