Application of Bacterial Cellulose (BC) in Natural Facial Scrub

A new facial scrub containing only natural ingredients and powdered bacterial cellulose (BC) was formulated. The other ingredients used in the formulation include powdered glutinous rice, aloe vera extract, ascorbic acid (Vitamin C) powder and olive oil. The rheological behaviours of the formulated and commercial facial scrubs were tested using plate and plate rheometer. Both formulated and commercial facial scrubs shows shear thinning  behaviour (non-Newtonian liquid). The formulated facial scrub sample had a higher viscosity at low shear rates compared to the commercial facial scrub (459.7 Pa.s against 359.2 Pa.s at 10s-1), but had a nearly similar viscosity at high shear rates (197.2 Pa.s against 192 Pa.s at 25s-1). By adding preservative, the shelf life of the scrub was two times longer than that without preservatives. The  tested sample dried out after 10 minutes at room temperature (~30°C)

Dielectric characterization of ethanol and sugar aqueous solutions for potential halal authentication

A potential method for detection and discrimination of alcoholic containing drinks for halal authentication using dielectric properties has been investigated. Behaviors of several concentrations of ethanol solutions in water were studied for verification purpose. The addition of three types of sugar namely sucrose, glucose and fructose show the effect and changes to dielectric properties of solutions. Dielectric constant and dielectric loss factor for each samples were measured over the microwave frequency from 0.5 to 50 GHz. The results showed that dielectric properties manage to discriminate alcohol content until the lowest concentration studied of 0.5% in water mixture. Beyond this limit, solution is considered as alcoholic drinks

Factors affecting dielectrophoretic separation of cells using high gradient electric field strength system

An investigation on dielectrophoretic separation of cells has been conducted using high-gradient electric field system (HGES). The HGES system consisted of two concentric cylindrical electrodes whereby the space between them was filled with glass beads. The glass beads were found to distort the electric field generated between the two electrodes and thus creating a high field gradient sites that produce dielectrophoretic force for cells collection. In order to study the effectiveness of the system in separating the cells, a series of experiments have been conducted. Here, yeast cells were introduced into the system and the number of cells collected was measured. The effects of voltage, flow rate, type of matrix, height of matrix and sample concentration have been investigated. In addition, the electric field analysis for the HGES has also been carried out using FEMLAB. Results show that the cells collection is influenced by the effect at the condition with and without electric field. Further analysis on the investigating factors enabled one to predict optimum values for voltage, flow rate, type of matrix, and height of matrix and sample concentration in order to improve the efficiency of the system by reducing the effect when no field is applied

Alternative for rapid detection and screening of pork, chicken, and beef using dielectric properties in the frequency of 0.5 to 50 GHz

Dielectric property at high microwave frequency region has been utilized for possible rapid detection and screening of different types of meat, especially for halal authentication. This investigation focused on both raw and sterilized (processed) beef, pork, and chicken samples. Dielectric response that consists of dielectric constant and dielectric loss factor was measured over the range of 0.5 to 50 GHz. All raw and sterilized meat samples could be differentiated by the dielectric values. Two distinct peaks were observed only for both raw and sterilized pork samples at the frequency around 7.43 and 31.19 GHz. These peaks can potentially be linked to compounds that exist only in pork such as DNA, microbes, enzyme, proteins, amino acids, and many others. Dielectric values for sterilized samples were lower than raw samples due to molecule structural changes that occurred in the samples. The dielectric results promise a great potential of utilizing dielectric properties as a rapid on-site detection approach prior to subsequent laborious analysis

Fluidized bed catalytic chemical vapor deposition synthesis of carbon nanotubes-a review

Carbon nanotubes (CNTs) are pure carbon in nanostructures with unique physico-chemical properties. They have brought significant breakthroughs in different fields such as materials, electronic devices, energy storage, separation, sensors, etc. If the CNTs are ever to fulfill their promise as an engineering material, commercial production will be required. Catalytic chemical vapor deposition (CCVD) technique coupled with a suitable reactor is considered as a scalable and relatively low-cost process enabling to produce high yield CNTs. Recent advances on CCVD of CNTs have shown that fluidized-bed reactors have a great potential for commercial production of this valuable material. However, the dominating process parameters which impact upon the CNT nucleation and growth need to be understood to control product morphology, optimize process productivity and scale up the process. This paper discusses a general overview of the key parameters in the CVD formation of CNT. The focus will be then shifted to the fluidized bed reactors as an alternative for commercial production of CNTs

Assessment on rheological and texture properties of xylitol-substituted dadih

Dadih is a dairy-based dessert made of milk, water, sugar and agar, which is popular especially among South East Asian people. It has sweet taste due to high sugar content in its formulation. An excessive intake of sugar is harmful to human health, and it would be beneficial if the conventional sugar is replaced by a sugar substitute. In order to formulate a healthier dadih, xylitol was used to replace sucrose in three different levels of compositions (0, 50 and 100%), which xylitol provides intense sweetness with fewer calories. Therefore, the objective of this study was to evaluate the effect of xylitol substitution on rheological and textural properties of xylitol-substituted dadih. Process parameters were cooking temperatures (85–95C) and cooking times (10–20 min). It was found that cooking temperature had the biggest impact on dadih. All samples showed gel-like behavior where the value of G′ (storage modulus) was higher than G″ (loss modulus). Samples that were prepared under high temperatures illustrated higher value of G′ with elastic gel property regardless of the xylitol composition. Sample prepared at 95C cooking temperature, 20-min cooking time and 0% xylitol exhibited the highest value of hardness and internal gel strength with 0.892 N ± 0.002 and 0.248 N ± 0.006, respectively. In general, the presence of xylitol in dadih contributed to its softer texture compared to a product that is made from sucrose. However, xylitol-substituted dadih prepared at 85C with longer cooking time (15 to 20 min) met the required texture as conventional dadih

Effect of ultrasonic pre-treatment on low temperature acid hydrolysis of oil palm empty fruit bunch

Various pre-treatment techniques change the physical and chemical structure of the lignocellulosic biomass and improve hydrolysis rates. The effect of ultrasonic pre-treatment on oil palm empty fruit bunch (OPEFB) fibre prior to acid hydrolysis has been evaluated. The main objective of this study was to determine if ultrasonic pre-treatment could function as a pre-treatment method for the acid hydrolysis of OPEFB fibre at a low temperature and pressure. Hydrolysis at a low temperature was studied using 2% sulphuric acid; 1:25 solid liquid ratio and 100 °C operating temperature. A maximum xylose yield of 58% was achieved when the OPEFB fibre was ultrasonicated at 90% amplitude for 45 min. In the absence of ultrasonic pre-treatment only 22% of xylose was obtained. However, no substantial increase of xylose formation was observed for acid hydrolysis at higher temperatures of 120 and 140 °C on ultrasonicated OPEFB fibre. The samples were then analysed using a scanning electron microscope (SEM) to describe the morphological changes of the OPEFB fibre. The SEM observations show interesting morphological changes within the OPEFB fibre for different acid hydrolysis conditions

Evaluation on safety and sensory analysis of xylitol substituted dadih

Dadih is a favourable dessert in South East Asia due to its appealing sweet taste and jellies appearance. The sweet taste is from sugar (sucrose) content, and in order to reduce the sucrose, it was substituted with xylitol. Xylitol can provides intense sweetness with less calories and lower water activity, which potentially contribute to higher microbial stability thus giving longer shelf life. The objective of this study was to evaluate the effect of xylitol substituted on dadih safety and sensory qualities. Dadih was prepared by replacing sucrose with xylitol composition in the range of 0 – 100% and at two levels of cooking times (15 and 20 minutes). Safety analysis were performed using total plate count (TPC) and water activity (aw) analysis. For sensory analysis, seven attributes were evaluated (appearance, colour, hardness, elasticity, taste, sweetness, and overall acceptability) based on the 9-hedonic scale. From the findings, dadih samples with total sucrose (0%) were observed to be contaminated faster compared to total xylitol (100%). Dadih with xylitol is more stable with prolonged shelf life. From sensory analysis, dadih sample prepared with shorter cooking time (15 minutes) was selected as more favourable with overall acceptability score between 72 - 85%. More than 70% of the score for dadih with xylitol substitute was above ‘slightly like’, which indicates a promising future to produce xylitol substitute dadih. The outcome of this study has shown that xylitol is potentially to be utilize as sugar substitute for dadih production

A newly isolated probiotic Enterococcus faecalis strain from vagina microbiota enhances apoptosis of human cancer cells

Aims: This study aimed to describe probiotic properties and bio-therapeutic effects of newly isolated Enterococcus faecalis from the human vaginal tract. Methods and Results: The Enterococcus faecalis strain was originally isolated from the vaginal microbiota of Iranian women and was molecularly identified using 16SrDNA gene sequencing. Some biochemical methodologies were preliminarily used to characterize the probiotic potential of Ent. faecalis, including antibiotic susceptibility, antimicrobial activity, as well as acid and bile resistance. The bio-therapeutic effects of this strain's secreted metabolites on four human cancer cell lines (AGS, HeLa, MCF-7 and HT-29) and one normal cell line (HUVEC) were evaluated by cytotoxicity assay and apoptosis scrutiny. The characterization results demonstrated into the isolated bacteria strain revealed probiotic properties, such as antibiotic susceptibility, antimicrobial activity and resistance under conditions similar to those in the gastrointestinal tract. Results of bio-therapeutic efficacy assessments illustrated acceptable apoptotic effects on four human cancer cell lines and negligible side effects on assayed normal cell line. Our findings revealed that the apoptotic effect of secreted metabolites mainly depended on proteins secreted by Ent. faecalis on different cancer cells. These proteins can induce the apoptosis of cancer cells. Conclusion: The metabolites produced by this vaginal Ent. faecalis strain can be used as alternative pharmaceutical compounds with promising therapeutic indices because they are not cytotoxic to normal mammalian cells. Accordingly, the physicochemical, structural and functional properties of the secreted anticancer substances should be further investigated before using them as anticancer therapeutics. Significance and Impact of the Study: This study aim to screen total bacterial secreted metabolites as a wealthy source to find the new active compounds to introduce as anticancer therapeutics in the future

Development of a hybrid PSO-ANN model for estimating glucose and xylose yields for microwave-assisted pretreatment and the enzymatic hydrolysis of lignocellulosic biomass

In this paper, two artificial intelligent systems, the artificial neural network (ANN) and particle swarm optimization (PSO), were combined to form a hybrid PSO–ANN model that was used to improve estimates of glucose and xylose yields from the microwave–acid pretreatment and enzymatic hydrolysis of lignocellulosic biomass based on pretreatment parameters. ANN is a powerful tool capable of determining the relationship between the desired input and output data while PSO was used as a robust population-based search algorithm to optimize the performance of the ANN model. Specifically, it was used to determine the optimum number of neurons in the hidden layer and the best value of the learning rate of the ANN model. The optimization method includes minimizing the fitness function mean absolute error that was found to be 0.0176. The PSO algorithm suggested an optimum number of neurons in the hidden layer as 15 and a learning rate of 0.761 these consequently used to construct the ANN model. After constructing the hybrid PSO–ANN model, the performance of the intelligent system was examined by determining the regression coefficient (R 2) for estimating the experimental values of glucose and xylose and compared to the results from a response surface methodology (RSM) model. The results of R 2 of the hybrid PSO–ANN model for glucose and xylose were 0.9939 and 0.9479, respectively, while the RSM model results for the same sugars were 0.8901 and 0.8439. This analysis reveals that the hybrid PSO–ANN model offers a higher degree of accuracy in comparison with the more commonly used RSM model