Revista Raízes e Amidos Tropicais

8

Authors: Fábio Iachel da Silva, Cláudio Cabello, Aura Cristina Bruder Pereira

The objective of his study was to adapt a methodology for molecule separation chain size, and to determine the molecular chain sizes of cassava starches. Results showed that gel permeation under low pressure was a suitable methodology for separating samples according to molecular chain size.

10

Authors: Magali Leonel, Silene B. S. Sarmento, Tainara B. Ferrari

Part of Brazil’s ginger crop is below export quality. The aim of this study was to increase the value of these remaining rhizomes by evaluating it as a raw material for the starch industry. Ginger rhizomes were chemically characterized and the starch obtained was evaluated for chemical composition, amylase content, granule shape and size, and pasting properties. Process yield was calculated from the mass balance. The ginger rhizomes had high moisture content (84.37%) and considerable starch content (11.42g/100g). The starch contained 20.38% amylase. The post starch extraction residue had high fiber content (3.8g/100g), which could be used as a fiber rich product. The mass balance showed that 69.7% of initial starch content was extracted during the process with a 7.2% yield. Starch granules were oval and circular in shape and diameters varied from 9.6 to 26.42m. Pasting temperature was 91.1ºC with high heat stability under mechanical agitation and low retrogradation tendency.

10

Authors: Walison Fábio Rogério, Magali Leonel, Marcelo Alvares de Oliveira

During agricultural production part of the roots and tubers are discarded because they are not of commercial quality. A possible way of adding value would be producing fried chips. The aim of this work was to evaluate quality characteristics of chips made from tropical tubers. Roots and rhizomes were characterized for chemical composition and chips for moisture content, lipids, calories, and texture. Results showed that taro (Colocasia esculenta) chips absorbed more fat (42.92g/100g), followed by sweet potato (Ipomoea batatas) (33.56g/100g), peruvian carrot (Arracacia xanthorrhiza) (33.95g/100g), and cassava (Manihot esculenta) chips (33.10g/100g). Yam (Dioscorea alata) chips had the least fat absorption (26.38g/100g). In relation to crisp texture, sweet potato chips had the least crunchy (240.2 g.f), and cassava chips the most crunchy texture (391.4 g.f). Sweet potato chips browned while frying. Taro chips were the highest in calories (611.26Kcal/100g); sweet potatoes had 581.76Kcal/100g, peruvian carrots 558.17Kcal/100g and cassava 556.35Kcal/100g, with the lowest in yam products (524.41Kcal/100g), showing a relationship with the fat absorption after frying. Results were interesting for yam chips due to low fat absorption, less calories, and texture.

20

Authors: Magali Leonel, Marcelo Alvares de Oliveira, Jaime Duarte Filho

The search for new starches to meet the demands of the consumer market means increased research into natural starches. The food industries are the largest starch consumers; however, it is also used in many industrial processes such as chemical and textile industries. This study aims to show the importance of tropical plants as potential sources of starch raw materials. Cultivation aspects were studied for different starch sources from Brazil and around the world, performing tuber and rhizome chemical composition analysis, agronomic evaluations, and yield assesments.