Effect of a-amylase source on enzymatic activity in Sorghum Starch Hydrolysis

Sorghum (Sorghum bicolor (L.) Moench) exhibit unique starches properties. These properties influence the digestibility of starch in the presence of a-amylases and can be a good raw material for glucose production. The aim of this research is to determine the susceptibility of amylase from different sources: a-amylases from human salivary, a-amylases from fungy (Aspergillus oryzae) and a-amylases from bacteria (Bacillus subtilis) and show how the source of amylase affects the atcivities in starch hydrolysis. Starch sorghum was isolated and purified in the laboratory from white and pigmented seeds of cultivars from Algeria In Salah). The enzymatic hydrolysis reactions were done in batch bioreactors and the reducing sugars obtained were determined quantitatively and qualitatively using HPAEC-PAD. The kinetic studies of enzymatic catalysis had allowed to identify of optimum operating conditions and to calculate enzymatic activities. The results showed a significant influence of amylase source on the kind of maltooligosaccharides. The fungal a-amylases is more efficient than bacterial a-amylases

Isolation and chemical characterization of pearl millet starches from Algeria

Starch is the most important carbohydrate in the human diet. Depending on botanical origin and genetic background, starch has different chemical structures, and so different functional properties. Native starch constitutes a key ingredient in numerous food and chemical applications as well as its modified products. The word production reaches 60 million tons with an average growth rate of 2,4 %. Industrially, Starch is isolated from corn, wheat and potato. Pearl millet grain cultivated in the Algerian Sahara present 59, 8 -68, 8 % of starch so we focused on isolation and characterization of this starch. For that, four (4) cultivar samples of pearl millet were collected from In Saleh, Tamanrasset (Algeria) and Agadez (Niger) regions and starch was isolated using modified alkaline method. The isolated starches were pure (93 – 97%). Some physicochemical and functional properties as granules size, thermal and rheological properties were determined. Pearl millet starches exhibit unique properties. Indeed, it has a high gelatinization temperature (75°C) and very high viscosity (4872 cP) compared to starches of pearl millet growing in other ecosystems and other botanical sources (corn, wheat ...). These properties makes them suitable for applications in cosmetic and pharmaceutical industries as powders, in food as Thickener and texturizing, and in chemistry industries as thin, resistant and biodegradable films for embedding or encapsulation