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.

Modification of Cassava Starch Using Lactic Acid Hydrolysis in The Rotary-UV Dryer to Improve Physichocemical Properties

“…Observations granules are very important for some applications [23]. According Moorthy [10] the size distribution of starch granules depends on the source and type of starch produced. In general, starch granules are round and oval.…”

Tratamento térmico do amido de batata-doce (Ipomoea batatas L.) sob baixa umidade em micro-ondas

“…As diferenças entre tratamentos foram se intensificando com o aumento da temperatura do teste de expansão, tornando-se mais evidentes após os 70 °C. Moorthy, 2002, em estudo sobre as propriedades de amido de diversas raízes tropicais, observou que um dos fatores que interferem no volume de expansão é o conteúdo de amilose (alta quantidade reduz o poder de expansão). No presente estudo houve correspondência entre aumento de teores de amilose e redução do fator de expansão dos grânulos de amido de batata-doce tratado no forno convencional em ambas as umidades.…”

Characterisation, in vitro digestibility and expected glycemic index of commercial starches as uncooked ingredients

“…Commercial native starches are mainly obtained from cereals, such as corn, wheat and rice in most developed countries, and from tubers or roots, such as potato and tapioca (or cassava) in countries as India, Brazil, Thailand, Indonesia, Philippines and China (Moorthy 2002). In particular corn is the main raw material for starch production, accounting for about 80 % of the world market.…”