Central Tuber Crops Research Institute

About: Central Tuber Crops Research Institute is a facility organization based out in Thiruvananthapuram, Kerala, India. It is known for research contribution in the topics: Starch & Fermentation. The organization has 475 authors who have published 587 publications receiving 10285 citations.

Physicochemical and Functional Properties of Tropical Tuber Starches: A Review

Abstract: The tropical tuber crops contain starch as the major component and thus act as important source of starch. Except cassava and to a smaller extent sweet potato, starch from other tuber crops has not been exploited for industrial applications partly because of difficulty in the extraction of the pure starches and partly because of non-availability of information about the properties of these lesser known starches. This review attempts at collating data available on the physicochemical and functional characteristics of the tropical tuber starches, highlighting their unique properties and potential field of applications. The physicochemical properties like granule shape and size, X-ray diffraction (XRD) patterns, amylose content, or content of non-starchy components, show considerable variation among the tuber starches. In addition, factors like genetic origin, environmental conditions and age of the plant also influence the properties. The starch granules of Colocasia esculenta and Dioscorea esculenta tubers are very small whereas those of Canna edulis are very large. XRD patterns of yam starches are generally ‘B’, while the aroid starches possess ‘A’ patterns. DSC gelatinisation temperatures are low for cassava starch and high for the aroid starches. The functional characteristics like viscosity, swelling power and solubility also depend on a number of factors such as varietal variation, method of extraction, processing conditions and instruments used for analysis. Viscosity is high for cassava and C. edulis starches, but low for most aroid starches. Clarity is good for cassava and yam starches compared to the others. Digestibility also varies among the starches. The diversity available in the tuber starches shows that some of the starches can be used in place of chemically modified starches available on the market. The realisation of their importance can help in value addition of these neglected crops and also provide starch with special properties for specific applications.

Cyanide detoxification in cassava for food and feed uses

Abstract: Cassava (Manihot esculenta Crantz) is an important tropical root crop providing energy to about 500 million people. The presence of the two cyanogenic glycosides, linamarin and lotaustralin, in cassava is a major factor limiting its use as food or feed. Traditional processing techniques practiced in cassava production are known to reduce cyanide in tubers and leaves. Drying is the most ubiquitous processing operation in many tropical countries. Sun drying eliminates more cyanide than oven drying because of the prolonged contact time between linamarase and the glucosides in sun drying. Soaking followed by boiling is better than soaking or boiling alone in removing cyanide. Traditional African food products such as gari and fufu are made by a series of operations such as grating, dewatering, fermenting, and roasting. During the various stages of gari manufacture, 80 to 95% cyanide loss occurs. The best processing method for the use of cassava leaves as human food is pounding the leaves and cooking the mash in water. Fermentation, boiling, and ensiling are efficient techniques for removing cyanide from cassava peels.

Effect of Cross‐linking with Epichlorohydrin on the Properties of Cassava (Manihot esculenta Crantz) Starch

Abstract: Cassava starch was cross-linked with epichlorohydrin (EPI) at 45°C for 2 h in three different media which include water, water in the presence of a phase transfer catalyst (PTC) and N,N-dimethylformamide (DMF). The products were characterized by determining their physicochemical, thermal and retrogradation properties. In aqueous medium, the use of a PTC, tetrabutylammonium bromide (TBAB) produced derivatives with higher degree of cross-linking than those prepared without the use of the catalyst. The degree of cross-linking was found to be higher using the same concentration of EPI when the reaction was carried out in DMF. At low levels of cross-linking, the peak viscosity of the cross-linked starches increased in comparison to that of the native starch. With increasing degree of cross-linking, the peak viscosity showed a significant reduction. The swelling volume, solubility and light transmittance of the starch pastes were lower for the modified starches. The cross-linked starches showed slightly reduced values for the gelatinization temperatures, Tonset, Tpeak and Tend. The enthalpy of gelatinization of the modified starches increased with increase in the degree of cross-linking. The modified starches exhibited higher water-binding capacities (WBC) than the native starch; but with increase in the degree of cross-linking, there was a gradual decrease in WBC. The in vitro alpha amylase digestibility of the modified starches decreased gradually with increase in the level of cross-linking.

Cassava Virus Diseases: Biology, Epidemiology, and Management

Abstract: Cassava (Manihot esculenta Crantz.) is the most important vegetatively propagated food staple in Africa and a prominent industrial crop in Latin America and Asia. Its vegetative propagation through stem cuttings has many advantages, but deleteriously it means that pathogens are passed from one generation to the next and can easily accumulate, threatening cassava production. Cassava-growing continents are characterized by specific suites of viruses that affect cassava and pose particular threats. Of major concern, causing large and increasing economic impact in Africa and Asia are the cassava mosaic geminiviruses that cause cassava mosaic disease in Africa and Asia and cassava brown streak viruses causing cassava brown streak disease in Africa. Latin America, the center of origin and domestication of the crop, hosts a diverse set of virus species, of which the most economically important give rise to cassava frog skin disease syndrome. Here, we review current knowledge on the biology, epidemiology, and control of the most economically important groups of viruses in relation to both farming and cultural practices. Components of virus control strategies examined include: diagnostics and surveillance, prevention and control of infection using phytosanitation, and control of disease through the breeding and promotion of varieties that inhibit virus replication and/or movement. We highlight areas that need further research attention and conclude by examining the likely future global outlook for virus disease management in cassava.