No abstract

No abstract

No abstract

No abstract

Microalga biomass has been recognized as a sustainable bio-product to replace terrestrial biomass in biofuel production. The microalga industry has high operating costs, specifically on harvesting and biomass recovery. Therefore, the development of an efficient harvesting method is crucial to the minimization of production cost. A statistical analysis through response surface methodology was used to investigate the optimization of harvesting efficiency using alum and chitosan as a coagulant. Growth rate and biomass productivity were also determined. This research revealed that the harvesting efficiency using alum was 99.3%, with optimum dosage and pH of 177.74 mg L and 8.24, respectively. Chitosan achieved 94.2% biomass recovery at an optimal dosage of 169.95 mg L at pH of 12. Moreover, Botryococcus sp. achieved the maximum growth of 0.7551 µ d, with an average total biomass productivity of 9.81 mg L d in domestic wastewater. Overall, this study shows that both alum and chitosan coagulants have great potential for efficient microalgal biomass recovery. It suggests that domestic wastewater as a potential growth medium for the large-scale production of microalga biomass.

Durian which is famous for its plentiful nutrition, is a delicious fruit from Southeast Asia with rising popularity worldwide. Since durian rinds are often thrown away as waste, it would be beneficial to transform it into value-added product like pectin. In general, pectin is a complex carbohydrate molecule which broadly applied in food industries such as stabilizer, texturizer, emulsifier, thickeners, gelling agent and many others. The purpose of this research is to determine pectin content in durian rinds using conventional acid extraction and to characterize the properties of pectin in terms of yield, water activity, moisture content and ash content. Pectin was extracted using hydrochloric acid at pH 2.5, 85°C for 60 minutes. The statistical analyses were conducted by using Statistical Package for the Social Sciences (SPSS) and data obtained were reported in mean and standard deviation. The results indicated that durian rinds pectin yield is 73.67%, 11.53% moisture content, 4.67% ash content, and 0.452 water activity. The overall study highlighted that durian rinds are rich source of pectin and it is likely to become a significant raw material for food industries. The results of this research show successful pectin extraction, acquiring potential advantages for industrial pectin extraction economically and environmentally.

Sonneratia caseolaris, also known as mangrove apple produces the edible fruit which can be found mainly on tidal mud in mangroves area. Since this fruit is considered as underutilized fruit as it is not fully discovered for its potential health benefits and not fully commercialized, hence this study aimed to determine the phytochemicals contents (i.e. total flavonoid, phenolic, anthocyanins and carotenoids contents), antioxidant and anticholinesterase activity of different parts (flesh and stem cap) of the unripe and ripe fruit extracts. Phytochemicals, antioxidant and anti-cholinesterase activities were determined using standard methods of spectrophotometric analysis. The flesh part of unripe S. caseolaris displayed the highest total phenolic, flavonoid and carotenoid contents as compared to the other parts in 80% methanol extract with the values of 67.67±0.10 mg (GAE/g), 37.06±0.30 mg (RE/g) and 5.41±0.10 mg (BC/100 g), respectively. The flesh part of unripe S. caseolaris in 80% methanol extract exhibited the best antioxidant properties in three different assays (i.e. DPPH, FRAP and ABTS) with the values of 98.32±0.28%, 67.72±0.74 mmol/g and 91.24±1.23 mg/g, respectively. The acetylcholinesterase inhibition also was found to be higher in the flesh part of unripe 80% methanol S. caseolaris extract with 47.18±0.68% at the concentration of 250 µg/mL. Therefore, utilization of this fruit as natural antioxidant and acetylcholinesterase inhibition sources may develop new pharmaceutical and nutraceutical products.

To maximise the production of xylanase, further optimisation was pedormed using exponential feeding. We investigated the effects of various nitrogen sources combined with the carbon to nitrogen (C/tI) molar ratio on the production of xylanase.Of the various nitrogen sources, yeast extact was found to be the most useful for recombinant xylanase production.