Enzymatic purification of glucomannan from Amorphophallus oncophyllus using α-Amylase / Purificação enzimática de glucomanan de amorphophallus oncophyllus usando α -amilasas

The international standards for top glucomannan flour require a minimum of 70% glucomannan. The glucomannan content of Amorphophallus oncophyllus flour was approximately 60%, with starch as the major impurity. Elimination of starch was expected to increase the purity of glucomannan. The purpose of this research was to study starch hydrolysis of the flour using α-amylase. Temperature (35.5-84.5oC), time (0.4-3.6 h) and pH (2.2-8.8) of hydrolysis were selected as independent variables. A central composite design of response surface methodology (RSM) was performed to obtain the optimum condition. This approach was a novelty of this enzymatic purification of A. oncophyllus. Glucomannan content, starch content, and solubility were chosen as the response variables. The models were reliable for predicting the responses (R2≥ 0.771). It was predicted that the highest glucomannan content (93.0%) obtained at the lowest starch content (1.14%), which hydrolysed at pH 6.17, 84.5oC and 3.6 h. Prior the verification of the optimum hydrolysed condition from the model, the glucomannan and starch content was 81.59% and 2.27%, respectively. After purification, the absorbance of the ß-1,4 glycosidic bond increased as a sign of higher glucomannan purity. A less rough surface and irregular shape of the grain morphology was observed after purification.

Os padrões internacionais para a farinha de alta calidade de glucomanan requerem um mínimo de 70% de glucomanan. O conteúdo de glucomanano da farinha de Amorphophallus oncophyllus foi de aproximadamente 60%, com o amido como a maior impureza. Esperava-se que a eliminação do amido aumentasse a pureza do glucomanan. O objetivo desta pesquisa foi estudar a hidrólise do amido da farinha usando α-amilase. A temperature (35,5-84,5oC), o tempo (0,4-3,6 h) e o pH (2,2-8,8) da hidrólise foram selecionados como variáveis independentes. Um desenho central composto pertencente á metodologia da superfície de resposta (MSR) foi realizado para obter a condição ótima. Esta abordagem foi uma novidade desta purificação enzimática de A. oncophyllus. O conteúdo de glucomanan, conteúdo de amido e solubilidade foram escolhidos como as respostas. Os modelos foram confiáveis para predizer as respostas (R2≥ 0,771). Os modelos indicaram que o maior conteúdo de glucomanan (93,0%) foram obtidos no menor conteúdo de amido (1,14%),que hidrolisou a um pH 6,17, 84,5ºC e 3,6 h. Antes da verificação da condição hidrolisada ótima do modelo, o conteúdo de glucomanan e amido foi de 81,59% e 2,27%, respectivamente. Após a purificação, a absorbância da ligação ß-1,4 glicosídica aumentou com um sinal de maior pureza de glucomanan. Uma superfície mais lisa e forma irregular da morfologia do grão foi observada após a purificação.

Effects of glucomanan on nitric oxide, endothelin and lipid peroxidation in atheroscierotic rabbits / 中国临床药理学与治疗学

AIM: To observe the effects of glucomanan on nitric oxide (NO), endothelin (ET), lipid peroxide and superoxide dismutase (SOD) in experimental atherosclerotic rabbits. METHODS: An atherosclerotic rabbit model was established by feeding high cholesterol diet supplemented by bovine serum albumin injection bolus. The rabbits were randomly divided into the control, model, and glucomanan treatment group. Blood samples were collected 8 weeks after the treatment. RESULTS: After glucomanan administration for 8 wk, the NO and activity of SOD increased in comparison with model group (P

Therapeutic effect of glucomanan on experimental diabetic mice / 中国药理学通报

AIM: To observe the therapeutic effect of glucomanan on diabetic mice. METHODS: The diabetic mice induced by alloxan model was established. The mices were randomly divided into the control and treated group to test level of blood glucose respectively. RESULTS: At doses of 100, 200 mg·kg-1 ig 1 and 4 h ahead of time, Glucomanan markedly reduced blood glucose level; At doses of 100, 200 mg·kg-1 ig, it markedly reduced blood glucose level of diabetic mice induced by alloxan; Useing glucomanan 100 mg·kg-1 ig bid x 3 d constantly reduced amount of water-drinking. CONCLUSION: Glucomanan may have significant effect on diabetic mice induced by alloxan.

Therapeutic effect of glucomanan on experimental diabetic mice / 中国药理学通报

AIM To observe the therapeutic effect of glucomanan on diabetic mice. METHODS The diabetic mice induced by alloxan model was established. The mices were randomly divided into the control and treated group to test level of blood glucose respectively. RESULTS At doses of 100,200 mg?kg -1 ig 1 and 4 h ahead of time,Glucomanan markedly reduced blood glucose level;At doses of 100, 200 mg?kg -1 ig,it markedly reduced blood glucose level of diabetic mice induced by alloxan;Useing glucomanan 100 mg?kg -1 ig bid?3 d constantly reduced amount of water-drinking. CONCLUSION Glucomanan may have significant effect on diabetic mice induced by alloxan.