Evaluation of Uncertainty in Determination of Reducing Sugar Content in Sugarcane

[ Objective] This study aimed to establish an effective method for evaluating uncertainty in determination of reducing sugar content in sugarcane with Lane-Ernon method. [ Method] Based on analysis of the main sources of uncertainty in determination of reducing sugar content in sugarcane and mathematical model construction, combined uncertainty and expanded uncertainty were determined to establish the method for evaluation of uncertainty in determination. [ Result] Among uncertainties in determination of reducing sugar content in sugarcane with Lane-Ernon method, the greatest uncertainty was introduced by duplicate determination. According to results of statistical analysis, the expanded uncertainty in determination of reducing sugar content was 0.012%. [ Conclusion] This study provided theo- retical reference for evaluation of uncertainty in determination of reducing sugar content in sugarcane.

Assessment of Physico-Chemical and Microbial Quality of Sugarcane Juice Sold by Street Vendors in Three Regions of Bangladesh

Sugar cane juice is a popular refreshing drink in most part of Bangladesh. It has great taste and health benefits;also it is available most of the public places at reasonable prices which consumed by road side customers including general public, shopping personals, tourists, students. In our country, street vendors crushing sugarcane between roller crusher and sold without any heat treatment or preservative, also served with or without added ice and lemon juice. The study aimed to identify and compare the physico-chemical and microbial quality of sugarcane juice. The chemical qualities of juices including moisture, PH, ash, total soluble solid, total sugar, reducing sugar and titrable acidity were found slightly different in Mymensingh, Gazipur and Narayangonj areas. The highest and lowest value of moisture, ash, PH, total soluble solids, total sugar, reducing sugar and titrable acidity were found in 84.33% - 79.26% (Gazipur-Mymensingh), 0.57% - 0.04% (Mymensingh-Gazipur), 5.9 - 2.9 (Gazipur-Narayangonj), 17.48% - 4.98% (Mymensingh-Narayangonj), 21.9% - 6.56% (Mymensingh-Gazipur), 3.7 - 2.1 (Gazipur-Mymensingh) and 0.523% - 0.007% (Narayangonj-Gazipur) respectively. For microbiological analysis, the total viable count of sugar cane juice in Mymensingh, Gazipur and Narayangonj were ranged from 0.6 × 105 - 43.6 × 105 cfu/ml, 4.6 × 105 - 21.6 × 105 cfu/ml and 3.6 × 105 - 36.6 × 105 cfu/ml respectively, where the permitted value is 1.0 × 104 cfu/ml, whereas the total coliform count was ranged from 0.4 × 105 - 6.4 × 105 cfu/ml, 0.6 × 105 - 8.4 × 105 cfu/ml and 0.00 - 8.4 × 105 cfu/ml, where the permitted value is 100 cfu/ml and total fungal count was ranged from 5.5 × 105 - 56.5 × 105 cfu/ml, 21.5 × 105 - 54.5 × 105 cfu/ml and 32.5 × 105 - 68.5 × 105 cfu/ml, where the permitted value is 1000 cfu/ml. According to the Gulf standard, the microbiological parameters of all the collected sugar cane juice were out of the permitted standards, so that a serious health outbreak can be caused anytime.

Effect of Rare Earth on Physiological-Chemical Characteristics and Its Growth of Aloe in Tissue Culture

In adopting tissue culture, effects of rare earth on Physiological and chemical characteristics, proliferation and rootage in aloe were studied. The results indicate that suitable concentration treatment of rare earth increases content of reducing sugar and protein, enhances activity intensity of superoxide dismutase (SOD), peroxidase (POD) isozymes and stripes of POD isozymes in the leaves. It also increases rate of proliferation and rootage respectively. The appropriate concentration of rare earth is 20～40 mg·L -1 in proliferation and rootage of aloe.

Identification and Quantification of Monosaccharides in Aloe vera Gel by Acid and Enzymatic Hydrolysis and Wet Heat Treatment

Aloe vera (Aloe barbadensis Miller) possesses curative and therapeutic properties attributed to the polysaccharides found in its tissue. This work aimed to study hydrolyzed (chemical and enzymatical) Aloe vera gel extracts using ultrafiltration membranes with a pore size of 0.22 micron (μm). Nine chemical treatments were achieved with H2SO4 and three wet heat treatments were carried out at a pressure of 1.2 lbf/in2 for 15 minutes;in both cases, three different concentrations of Aloe vera gel juice (AGJ) were used: 1.5%, 2.5% and 3.5% w/w. The concentrations of H2SO4 were 0.10%, 0.25% and 0.40% w/w. Chemical experiments are performed over a factorial 32 design and results were analyzed using SPSS software (version 17, SPSS Inc.), finding the one labeled T7 (15 ml of AGJ 3.5% with 15 ml of H2SO4 0.10% added) the best of them, as it leaded to 0.0446 mg/ml of liberated glucose. Among the three wet heat treatments, the one labeled TC3 (15 ml of AGJ 3.5% with 15 ml of H2O added) was the best-performing one, as it leaded to 0.292 mg/ml of liberated glucose. Furthermore, an enzymatic hydrolysis was carried out using Novozymes’ Pectinex? AR and Viscozyme?. Hydrolisis with both enzymes yield to better results than acid hydrolysis: in the treatment with Pectinex? AR, 3.282 mg/ml of liberated glucose were obtained and 3.302 mg/ml in the treatment with Viscozyme?. The hydrolyzed substances obtained by acid and enzymatic hydrolysis, as well as by wet heat treatment, were subsequently analyzed by thin layer chromatography (TLC), using glucose, galactose and arabinose 1000 ppm solutions as reference patterns. Among the treatments by H2SO4, the one labeled T4 obtained an Rf value of 50, the same as on the galactose reference pattern.

Flavor changes in Lentinus Edodes enzymatic hydrolysate maillard reaction products with different sugars by gas chromatography‐ion mobility spectrometry

The characteristic flavor of the enzymatic hydrolysate of Lentinus edodes,which was involved in the Maillard reaction by xylose,fructose,glucose,sucrose,mannose,maltose,vitamin C(VC)and L-arabinose,was determined and analyzed by gas chromatography-ion mobility spectroscopy(GC-IMS).The characteristic flavor fingerprints of Maillard reaction products(MRPs)of L.edodes enzymatic hydrolysate were constructed.The differences in the characteristic flavors of Maillard reaction with different reducing sugars and VC were compared.The main characteristic flavor,characteristic peak,characteristic marker substance and content were determined,a principal component analysis(PCA)of volatile organic compounds(VOCs)was carried out.The results showed that there were 42 kinds of monomers and some dimers of volatile compounds in the samples including 17 aldehydes,5 alcohols,7 ketones,2 esters,2 acids,7 other compounds and 2 ethers.The volatile VOCs of the sample with added sucrose,VC and L-arabinose were significantly higher than those of the enzymatic hydrolysate of L.edodes.After the Maillard reaction,the flavor of the hydrolysate was significantly improved,and the main components changed significantly.

Optimization of sugar production from Durian seeds via alkaline hydrolysis for second-generation bioethanol production

As one way to eliminate the issues found in the preceding generation,feedstock exploration in second-generation bioethanol production remains an issue,especially for a tropical country such as Indonesia.From exotic fruit by-products,durian holds a promising perspective that rests on its abundance,superb carbohydrate content and limited usage until now.This work presents the first-ever utilization of durian seeds for sugar production under optimized conditions through alkaline hydrolysis.A simple form of sugar was extracted by varying four parameters,namely substrate loading,NaOH concentration,hydrolysis time and hydrolysis temperature.Response surface methodology based on the Box-Behnken design was employed to outline the most optimum parameter values.Analysis of variance revealed that the quadratic model fit the data appropriately with the order of significance as substrate loading>hydrolysis time>NaOH concentration>hydrolysis temperature.The optimized conditions for reducing sugar yield,as high as 2.140 g/L,corresponded to<50 g/L substrate loading,0.522 M NaOH,60 minutes of hydrolysis time and 80oC hydrolysis temperature.The possible ethanol content of 1.094 g/L was also expected under optimized conditions,demonstrating great potential in second-generation bioethanol production.

Zebra chip disease incidence on potato is influenced by timing of potato psyllid infestation, but not by the host plants on which they were reared

The Zebra chip （ZC） syndrome is an emerging disease of potato and a major threat to the potato industry. The potato psyllid, Bactericerca cockerelli （Sulc） is believed to be a vector of the ZC pathogen, which is now thought to be Candidatus Liberibacter, a bacterium. To further understand the relationship between potato psyllid infestation and ZC disease expression, healthy potato plants at different growth stages （4, 6 and 10 weeks after germination） were exposed separately to potato psyllids that were separately reared on four solanaceous hosts plants （potato, tomato, eggplant or bell pepper） for more than 1 year. ZC symptoms, leaf rates and total nonstructural carbohydrate accumulation in leaves and tubers of healthy and psyllid-infested plants were monitored and recorded. Typical ZC symptoms were observed in leaves and tubers of all plants exposed to potato psyllids regardless of the host plant on which they were reared. This was also accompanied by significant reductions in net photosynthetic rate. Caged potato plants without exposure to potato psyllids （uninfested controls） did not show any ZC symptom in both foliage and in harvested tubers. Foliage damage and ZC expression were most severe in the potato plants that were exposed to potato psyllids 4 weeks after germination compared to plants infested at later growth stages. Tubers from potato psyllid-infested plants had significantly higher levels of reducing sugars （glucose） and lower levels of starch than those in healthy plants, indicating that potato psyllid infestation interfered with carbohydrate metabolism in either leaves or tubers, resulting in ZC expression.

Impact of double alkaline peroxide pretreatment on enzymatic hydrolysis of palm fibre

A double pretreatment was developed to improve the efficiency of enzymatic hydrolysis and to increase the sugars production from palm fibre in batch and fed-batch systems.After alkaline peroxide pretreatment using NaOH-H_(2)O_(2)solution,rigid structure of palm fibre was broken and partial of the hemicelluloses and lignin were removed.Compared with cellulase Accellerase^(■)1500,when using the conjunction of Accellerase^(■)1500 and Optimash BG,the conversion ratio increased from 35.9%to 45.0%and the reducing sugar yield increased from 245 mg/g substrate to 307 mg/g substrate.To further increase the hydrolysis efficiency,double pretreatment with NaOH-H_(2)O_(2)solution was used to treat the hydrolysized residues.Then,the hydrolysis ratio reached 93%and reducing sugar yield was 752 mg/g substrate.Fed-batch enzymatic hydrolysis was carried out with 7%(w/v)solids loading and 0.3 mL/g substrate.Then,7%solids were fed consecutively at 12 h,24 h,36 h and 48 h.After 144 h,the final concentration of reducing sugar reached 214.0 g/L and total biomass conversion ratio was 75.23%.