Abstract: The β-glucan produced by Ophiocordyceps dipterigena BCC 2073 is a (1, 3)-β-D-glucan with highly branching O-6-linkedside chains that is resistant to acid hydrolysis (by hydrochloric acid and porcine pancreatic alpha-amylase). This β-glucan can be utilized as a prebiotic due to its advantageous structural and biological properties. The effects of using this β-glucan as the sole carbon source for the in vitro growth of two probiotic bacteria (L. acidophilus BCC 13938 and B. animalis ATCC 25527) were investigated. Compared with the effect of using 1% glucose or fructo-oligosaccharide (FOS) as the sole carbon source, using 1% β-glucan for this purpose showed that this prebiotic supported and stimulated the growth of both types of probiotic bacteria and induced them to produce the highest levels of metabolites during their growth. The highest levels of lactic and acetic acid, 10.04 g·L-1 and 2.82 g·L-1, respectively, were observed at 2 h of cultivation using glucose as the sole carbon source. Furthermore, the fermentation broth obtained using 1% β-glucan as the sole carbon source had greater antibacterial activity against selected pathogenic bacteria (B. subtilis TISTR 008, E. coli TISTR 780, and S. typhimurium TISTR 292) than did the broths prepared using glucose or FOS as the sole carbon source. The fermentation broth obtained by growing L. acidophilus BCC 13938 in the presence of β-glucan inhibited the growth of B. subtilis TISTR 008 by more than 70% and inhibited the growth of both S. typhimurium TISTR 292 and E. coli TISTR 780 by more than 90%. In conclusion, O. dipterigena BCC 2073 is a potential source of a β-glucan prebiotic that could be used for commercial production in the near future.
Abstract: Theoptimal extraction condition of dried Phaseolus
vulgaris powderwas studied. The three independent variables are raw
material concentration, shaking and centrifugaltime. The dependent
variables are both yield percentage of crude extract and alphaamylase
enzyme inhibition activity. The experimental design was
based on box-behnkendesign. Highest yield percentage of crude
extract could get from extraction condition at concentration of 1, 0,1,
concentration of 0.15 M ,extraction time for 2hour, and
separationtime for60 min. Moreover, the crude extract with highest
alpha-amylase enzyme inhibition activityoccurred by extraction
condition at concentration of 0.10 M, extraction time for 2 min, and
separation time for 45 min
Abstract: Wheat has a bimodal starch granule population and the dependency of the rate of enzymatic hydrolysis on particle size has been investigated. Ungelatinised wheaten starch granules were separated into two populations by sedimentation and decantation. Particle size was analysed by laser diffraction and morphological characteristics were viewed using SEM. The sedimentation technique though lengthy, gave satisfactory separation of the granules. Samples (10μm and original) were digested with a-amylase using a dialysis model. Granules of 10μm (p10μm. Moreover, the digestion rate was dependent on particle size whereby smaller granules produced higher rate of release. The methodology and results reported here can be used as a basis for further evaluations designed to delay the release of glucose during the digestion of native starches.
Abstract: Cassava bagasse is one of major biomass wastes in Thailand from starch processing industry, which contains high starch content of about 60%. The object of this study was to investigate the optimal condition for hydrothermally pretreating cassava baggasses with or without acid addition. The pretreated samples were measured reducing sugar yield directly or after enzymatic hydrolysis (alpha-amylase). In enzymatic hydrolysis, the highest reducing sugar content was obtained under hydrothermal conditions for at 125oC for 30 min. The result shows that pretreating cassava baggasses increased the efficiency of enzymatic hydrolysis. For acid hydrolysis, pretreating cassava baggasses with sulfuric acid at 120oC for 60 min gave a maximum reducing sugar yield. In this study, sulfuric acid had a greater capacity for hydrolyzing cassava baggasses than phosphoric acid. In comparison, dilute acid hydrolysis to provide a higher yield of reducing sugar than the enzymatic hydrolysis combined hydrothermal pretreatment. However, enzymatic hydrolysis in a combination with hydrothermal pretreatment was an alternative to enhance efficiency reducing sugar production from cassava bagasse.
Abstract: Enzymatic hydrolysis of starch from natural sources
finds potential application in commercial production of alcoholic
beverage and bioethanol. In this study the effect of starch
concentration, temperature, time and enzyme concentration were
studied and optimized for hydrolysis of cassava (Manihot esculenta)
starch powder (of mesh 80/120) into glucose syrup by immobilized
(using Polyacrylamide gel) a-amylase using central composite
design. The experimental result on enzymatic hydrolysis of cassava
starch was subjected to multiple linear regression analysis using
MINITAB 14 software. Positive linear effect of starch concentration,
enzyme concentration and time was observed on hydrolysis of
cassava starch by a-amylase. The statistical significance of the model
was validated by F-test for analysis of variance (p < 0.01). The
optimum value of starch concentration temperature, time and enzyme
concentration were found to be 4.5% (w/v), 45oC, 150 min, and 1%
(w/v) enzyme. The maximum glucose yield at optimum condition
was 5.17 mg/mL.
Abstract: The influence of humidity and low temperature on the α- amylase activity and isoenzyme composition of grains of different wheat varieties have been studied. The identified samples of varieties have significant difference in the level of enzyme induction under the impact of high humidity and low temperature. It is proposed to use this methodological approach for testing genotypes and wheat breeding lines for resistance to pre-harvest sprouting (PHS).
Abstract: In the present study, the effects of ultrasound as
emerging technology were investigated on germination stimulation,
amount of alpha-amylase activity on dry barley seeds before steeping
stage of malting process. All experiments were carried out at 20 KHz
on the ultrasonic generator in 3 different ultrasonic intensities (20, 60
and 100% setting from total power of device) and time (5, 10 and 15
min) at constant temperature (30C). For determining the effects of
these parameters on enzyme the Fuwa method assay based on the
decreased staining value of blue starch–iodine complexes employed
for measurement an activity. The results of these assays were
analyzed by Qualitek4 software using the Taguchi statistical method
to evaluate the factor-s effects on enzyme activity. It has been found
that when malting barley is irradiated with an ultrasonic power, a
stimulating effect occurs as to the enzyme activity.