Farmers’ choice of varieties and demand for improved cassava stems in Nigeria

In this study, we used a household level survey to assess choices of varieties and demand for improved cassava varieties. A multivariate probit model was used to examine the determinants of choice decisions of the farmers for different varieties preventing potential endogeneity and measurement error. A Linearized Almost Ideal Demand System (LA/AIDS) model was used to analyze the demand system for improved cassava varieties. The results of the (LA/AIDS) model indicated farmers were very price sensitive to changes in improved stem prices and incomes. We suggest that intervention program that will improve the purchasing power of the farmers should be targeted towards the smallholder cassava farmers to accelerate adoption of improved cassava varieties. Int. J. Agril. Res. Innov. Tech. 11(2): 42-51, Dec 2021

Proximate Composition, Physicochemical, Functional, and Antioxidant Properties of Flours from Selected Cassava (Manihot esculenta Crantz) Varieties

Cassava flour has a high potential to contribute as a raw material in the food industry. This study was aimed at characterizing flours from Sri Lankan cassava varieties with a view to explore the potential in food applications. Flours prepared from five cassava varieties, namely, Kirikawadi, MU51, Swarna, Shani, and Suranimala, were analyzed for proximate composition and physicochemical, functional, and antioxidant properties using standard methods. Flours from tested cassava varieties contained <1% crude fat and <2% crude protein. Flour from MU51 contained the highest amount of HCN (48.05 mg/kg) while flour from Suranimala contained the lowest (4.85 mg/kg). Total starch and amylose contents of flours were significantly lower ( p < 0.05 ) than those of commercial wheat flour. Flour from Suranimala contained approximately similar amylopectin content as commercial wheat flour. Water absorption capacity, oil absorption capacity, water solubility index, swelling power, emulsion activity, and emulsion stability of flours from five cassava varieties were significantly higher ( p < 0.05 ) than those of commercial wheat flour. Swarna was identified as the richest source of phenolic compounds (4.44 mmol GAE/100 g dry weight) among the five varieties. Results showed the promising application potential of flours from these five cassava varieties in different food applications such as weaning foods, bakery foods, and edible films.

Application of crude pectolytic enzymes from Saccaharomyces cerevisiae (ATCC 52,712) to starch extraction in Ghana: effects of enzyme technology on pasting characteristics in different cassava varieties

Previous work on enzyme application to starch extraction enhanced yield and starch recovery rates as well as modified some physicochemical properties of starches for potential alternative application to industry. The response of the technology, however, showed some sensitivity to variety. The knowledge gap therefore was to establish whether such physicochemical responses (by the technology) to variety affects the pasting parameters of the starches extracted. The pasting parameters of starches extracted from four different cassava varieties (‘Nkabom’, ‘Afisiafi’, ‘Bankyehemaa’ and ‘Esambankye’), with the aid of crude pectolytic enzymes from the Saccharomyces cerevisiae (ATCC 52,712), were investigated. Although a general response pattern was observed for most of the pasting parameters measured, which includes general enhancements (P < 0.05) in starch gelatinization viscosity, with improvements in gelatinization time and temperature and peak viscosities in most of the varieties, there were significant differences (P < 0.05) in their respective peak time and temperature requirements for the attainment of peak viscosity. Values for the breakdown viscosity were also generally increased (P < 0.05). The technology also increased values for setback viscosity in both the ‘Nkabom’ and ‘Bankyehemaa’ varieties but reduced setback values in the ‘Afisiafi’ and ‘Esambankye’ varieties. As pasting properties are one of the most important characteristics of starch that determine its overall utility, knowledge from this study should inform how adoption of the technology would help diversify the various cassava varieties for appropriate domestic and industrial applications while harnessing its benefits of improved starch yield.

Untargeted Metabolomics Profiling of High Beta Carotene Cassava with respect to Postharvest Physiological Deterioration

Cassava roots undergo postharvest physiological deterioration (PPD), and for most varieties it sets in within 72 hours of harvest. An untargeted metabolomics approach combined with a data-driven approach for statistical analysis was used to characterize and profile high beta-carotene cassava varieties with the aim of identifying any relevant metabolite changes that occur during PPD. Sixteen cassava root samples from four cassava lines were planted in a greenhouse and harvested after four months. The samples included four of 2 conventionally bred beta carotene cassava varieties &ndash; UMUCASS 38, UMUCASS 45 and four of 2 transgenic high beta carotene cultivars - EC20-7 and EC20-8 cassava lines. Extracts of fresh cassava roots from 20-100 mg tissues were used for the analyses and data were processed using Elements for Metabolomics software. Starch and lipid metabolites were the major constituents which may help explain the observed differences in starch and dry matter content among the varieties. The results provide further insight in the understanding of PPD and suggestions on controlling this deterioration in cassava are made.

ANALYSIS OF GENETIC DIVERSITY OF 26 CASSAVA VARIETIES (Manihot esculenta CRANTZ) WITH DIFFERENT RESPONSES TO WATERLOGGING CONDITIONS BY USING RAPD MARKERS

RAPD (Randomly Amplified Polymorphic DNA) is an indicator for high and stable polymorphism, widely used in the study of the diversity of cassava. In this paper, the results of using 20 polymorphic primers OPK combined with the establishment of the phylogenetic tree to analyze the genetic diversity of 26 cassava varieties with different responses to waterlogging conditions by using the RAPD-PCR technique were presented. The purpose of this experiment was to show the genetic relevance of the studied cassava varieties. The results showed that the flood tolerance of cassava was not related to the polymorphism and branching characteristics of the stem. This information may be use as a basis for selecting flood-tolerant cassava varieties for cassava production, as well as the basis for selecting genetically different parents for breeding.