Production of drum-dried jackfruit (Artocarpus heterophyllus) powder with different concentration of soy lecithin and gum arabic

The aim of the present study was to determine the optimum concentration of soy lecithin and gum arabic in producing drum-dried jackfruit (Artocarpus heterophyllus) powder using response surface methodology (RSM). Jackfruit puree was dried using a double drum drier set at 1 rpm, drum clearance of 0.01 in., and steam pressure of 2.3 bar. Soy lecithin and gum arabic were incorporated into jackfruit puree at different concentrations ranged from 1% to 5% and 5% to 15%, respectively. Soy lecithin and gum arabic were significant factors (at 95% confidence level) for moisture content, bulk density, Hunter L, a, b values and hedonic test during drum drying of jackfruit. A second-order polynomial model was found for each of the significant response. The jackfruit puree formulation to produce a good quality powder could be obtained by incorporating 2.65% of soy lecithin and 10.28% of gum arabic into the jackfruit puree (40% v/w water)

Waste recycling in Malaysia: problems and prospects

Recycling of solid wastes should be integrated into the existing and future waste management plans so as to yield the benefits of conservation of natural resources, saving of fossil fuels and prolonging lifespan times of disposal sites. This paper discusses the current status of waste recycling in Malaysia and its future prospects. Although a large amount of Malaysian wastes could be recycled, less than 5% of the total (almost 10 000 t d-1) is actually separated and recycled. There is a good demand for waste plastics, paper and glass, with resale prices of about US$60 t-1, US$44 t-1 and US$32 t-1, respectively. Recovery of only 5$3.4 million y-1. Recommendations to increase recycling are discussed in the paper

Proses penyahnitratan dan penyahwamaan di dalam reaktor lapisan terkembang

Synthetic textile wastewater was biologically treated in aerobic and anaerobic expanded bed reactors. The objectives of this study are to investigated the reduction of COD (Chemical Oxygen demand), denitrification process, decolourisation process and other related parameters. Experimental work was done using perspec columns resctors which were innoculated with mixed culture. Granulated activated carbon was used as a support medium. Samples were analysed for their outlet and inlet COD, outlet and inlet nitrate, pH, temperature and biomass. It was observed that, a good removal of COD, nitrate and colour were obtained. The results shows that aerobic condition with dissolved oxygen less than 2.0 mg/L could reduce the accumulation of toxid on the biofilm surface and could 'increase the efficiency of COD reduction as well as denitrification and decolourisation process for a longer period. The results also proved that simulatenous biodecolourisation and biodenitrification could a single reactor for both system

Modelling of solid waste incineration

A model for incineration of municipal solid wastes was formulated based on material and energy balances and reaction kinetics. The model was tested for various air supply rates. The study has given a picture of variations in the incineration chambers. The simulations has also shown that the slowest stages in the incineration process is the initial feed heating and the water vapourisatio

Specificity of acclimated biodecolourisation culture to cosubstrate structure

Experiments on using acclimated culture were carried out to determine if compounds other than glucose could be effective as cosubstrate in biodecolourisation of an azo dye. The role of cosubstrate was found to be not structure dependent hence cometabolism was not likely to be involved in biodecolourisation. This finding also offers opportunities for use of carbon sources other than glucose and for mixing of wastewaters to facilitate biodecolourisatio

Effects of aeration on biodecolourisation of azo dye

A study on the effects of aeration on biodecolourisation of an azo dye was carried out using acclimated culture. Oxidation reduction potential was used as a measure of degree of aeration. The results showed biodecolourisation to be dependent on degree of aeration with negative or very low oxidation reduction potential being favourable for decolourisation. This finding was in line with the postulation that biodecolourisation occurred via azo bond cleavag

Kajian mata air panas di Semenanjung Malaysia

Kajian menyeluruh ke atas mata air panas di Semenanjung Malaysia telah dilakukan untuk mendapatkan maklumat geologi, suhu, kadar aliran dan kualiti air panas serta potensi untuk dibangunkan bagi industri pelancongan. Kajian geologi menunjukkan kebanyakan mata air panas ini terletak di dalam atau berhampiran kawasan batuan granit dan berasosiasi dengan zon sesar. Air panas ini mempunyai julat suhu daripada 27°C hingga 103°C dan kadar aliran daripada 0.1 hingga 27.0 L/S. Analisis kimia menunjukkan kesemua air panas ini mengandungi kandungan garam dan logam terlarut yang rendah

e-Waste Management Scenarios in Malaysia

e-Waste, or electronic waste, disposal that is uncontrolled can be harmful to human health and the environment because e-waste contains toxic substances and heavy metals. However, if the waste is properly managed, it can become a business opportunity that produces high returns because e-waste also contains valuable materials, such as gold, silver, platinum, and palladium. The government of Malaysia wants to ensure the safe, effective, and economically beneficial management of e-waste in Malaysia. Management approaches have included law enforcement and regulation and the promotion of e-waste recovery activities. e-Waste of no commercial value must be disposed of at sites/premises licensed by the Department of Environment (DOE), Malaysia. To date, 18 full recovery facilities and 128 partial recovery facilities that use various available technologies have been designated for the segregation, dismantling, and treatment of e-waste. However, there are issues faced by the recovery facilities in achieving the goal of converting e-waste into a source material. The issues include the e-waste supply, the importation of e-waste derived products and coding, and finally the need to develop the criteria for e-waste processing technologies to ensure the safety and the sustainability of the facilities

Optimization of hot water extraction for sapodilla juice using response surface methodology.

A central composite design was employed to optimize the extraction conditions of sapodilla juice using hot water extraction. The independent variables were juice extraction time (30–120 min) and temperature (30–90 C). The combined effect of these variables on juice yield, odour, taste and astringency were investigated. Results showed that the generated regression models adequately explained the data variation and significantly represented the actual relationship between the independent variables and the responses. The results showed that extraction temperature was the most important factor affecting the juice characteristics as it exerted a significant influence on all the dependent variables. Higher temperature increased the juice yield, taste and odour but also showed an increase in astringency which affected the acceptability of the juice. The contour plots showed the relationships between the independent variables and the responses were developed. By superimposed of the contour plots, optimum condition of 60 C for 120 min was established for hot water extraction of sapodilla juice

Optimization of enzymatic clarification of sapodilla juice using response surface methodology

Response surface methodology is a statistical procedure frequently used for optimization studies. It uses quantitative data from an appropriate experimental design to determine and simultaneously solve multivariate problems. In this study, a two-factor central composite design was used to establish the optimum conditions for enzymatic clarification of sapodilla juice. Sapodilla juice was treated with pectinase enzyme at different incubation times (30–120 min), temperature (30–50 °C) and enzyme concentration (0.03–0.10%). These three factors were used as independent variables whose effects on turbidity, clarity, viscosity and colour (L values) were evaluated. Significant regression models describing the changes of turbidity, clarity, viscosity and colour (L values) with respect to the independent variables were established, with the coefficient of determination, R2, greater than 0.8. The results indicated that enzyme concentration was the most important factor affecting the characteristics of the juice as it exerted a significant influence on all the dependent variables. The recommended enzyme clarification condition was 0.1% enzyme concentration at 40 °C for 120 min