Showing papers by "Central Tuber Crops Research Institute published in 1998"

Cassava Fermentation and Associated Changes in Physicochemical and Functional Properties

Abstract: Fermentation of cassava is an important processing technique followed in different parts of the world. Although fermentation is known to bring about vast changes in the physicochemical and functional properties of the tubers, attempts have seldom been made to consolidate and critically analyze the available information. Glaring inconsistencies and contradictions noticeable in some of the results reflect the differences and variations in the artisanal processes followed in the preparation of these products. It also stresses the need for a systematic study of not only the quoted products, but also a number of other fermented cassava products that have not been well documented.

Cyanogen Accumulation in Environment During Processing of Cassava (Manihot Esculenta Crantz) for Starch and Sago

Abstract: Starch and Sago production from cassava (Manihot esculenta Crantz) roots is an increasingly important agro industry. Casssava is one of many cyanogen containing plants. In the present study the amount of cyanogens present in the waste waters and ground waters collected from the starch/sago processing industries in Salem, the main centre of cassava starch and sago production in India was assessed. Concentration of total cyanogens ranged between 12.9 to 66.6 mg l-1 (as HCN) in the initial processing stages whereas the final discharge contained 10.4 to 27.4 mg l-1. Linamarase activity of the waste water samples ranged between 3350 to 3370.6 µmoles l-1 15 min-1. The ground water sources near cassava starch/sago factories showed much higher cyanogen concentration than the acceptable level. The level of total cyanogen in the samples of ground water ranged between 1.2 mg l-1 to 1.6 mg l-1.

Occurrence of hexaploid males in Dioscorea alata L.

Abstract: In the polyploid species Dioscorea alata, earlier studies have shown a prevalence of higher ploidy levels (2n = 60 and 80) restricted among female clones. Cytological screening of a number of rare flowering collections maintained at the CTCRI revealed the occurrence of hexaploids (2n = 60) among male clones for the first time. The hexaploid males were sparse flowering, showing irregular meiosis leading to very high pollen sterility. On the basis of the diploid chromosome number 2n = 20 in the Old World Dioscorea, the trivalent forming 2n = 60 male is considered as an autoallohexaploid.

Effect of processing on amylase and protease inhibitor activity in tropical tubers

Abstract: The effect of various processing methods on amylase, trypsin and chymo-trypsin inhibitory activities in tubers of Colocasia esculenta (taro), Xanthosoma sagittifolium (tannia), Solenostemon rotundifolius (Coleus, Chinese potato), Dioscorea esculenta (lesser yam) and Amorphophallus paeoniifolius (elephant foot yam) was studied. Among the different methods, frying was the most effective method of eliminating enzyme inhibitors from tubers. When cooked by boiling, partial retention (30 to 60%) of enzyme inhibitory activity was observed in certain tubers. Further reduction in inhibitory activity was observed in baked/pressure cooked tubers. The study indicated that processing decreased the inhibitor content significantly and the reduction of inhibitory activity was brought about by heat inactivation.