Pyrodextrinization of yam (Dioscorea sp.) starch isolated from tubers grown in Brazil and physicochemical characterization of yellow pyrodextrins.

This study optimizes the pyrodextrinization of yam (Dioscorea sp.) starch isolated from tubers grown in Brazil to produce a yellow pyrodextrin with the lowest enzymatically available starch (AS) content and color difference (ΔE) index. At 140 °C (fixed heating temperature), the effects of acid concentration (0.

Digestibility of starches isolated from stem and root tubers of arracacha, cassava, cush-cush yam, potato and taro.

Digestibility of arracacha, cassava, cush-cush yam, potato and taro starches was evaluated. In vitro (potentially-available starch and total resistant starch) and in vivo digestibility in the rice weevil (Sitophilus oryzae) bioassay (survival, weight variation, α-amylase like activity [ALA], and uric acid excretion [UAE] as biomarkers) were estimated. In in vitro assays, all starches presented high resistant starch content (14-56%, dry basis), except for cassava starch.

[Applicability of multivariate statistics for nutritional studies: bioassay rice weevil (Sitophilus oryzae L)].

The principal component analysis (PCA), non-metric multidimensional scaling (MDS) and analysis of similarity (ANOSIM) are multivariate statistical techniques that graphically represent numerical measures of several factors and display multiple relationships that may exist between them. In this study, we evaluated the applicability of these techniques to analyze the nutritional quality of diet, using as model, the bioassay rice weevil. The diets tested were: corn starch, potato starch, 5% glucose, peas, starved and starved with water supply.

Differential fermentation of glucose-based carbohydrates in vitro by human faecal bacteria--a study of pyrodextrinised starches from different sources.

Background: Pyrodextrins, modified starches produced by heat/acid treatment, have been used extensively in the paper industry. Recently, pyrodextrinisation has been recognised as a way of producing a "resistant starch" that is water-soluble and has non-starch linkages. However, a full characterisation of the fermentation properties of pyrodextrins has not been reported.

Preparation of indigestible pyrodextrins from different starch sources.

Starch-modifying processes, such as pyrodextrinization, are potential ways to alter the nutritional features of this polysaccharide. A widely used method for pyrodextrinizing maize starch was also applied to lentil, sorghum, cocoyam, sagu, and cassava starches, and the in vitro digestibility of the products was evaluated. Pyrodextrins were produced by heating starch at 140 degrees C for 3 h, with catalytic amounts of HCl.