Noorulnajwa Diyana Yaacob
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Preferred name
Noorulnajwa Diyana Yaacob
Official Name
Noorulnajwa Diyana, Yaacob
Alternative Name
Yaacob, Noorulnajwa Diyana
Yaacob, N.
Yaacob, Noorulnajwa Diyana
Main Affiliation
Scopus Author ID
54893883300
Researcher ID
GWC-3136-2022

Research Output
Now showing 1 - 6 of 6
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Publication

Effect of cold exposure on the biofoam produced from different types of Oyster mushroom

2024-07 , Tan Siu Siew , Nur Mawaddah Majib , Sam Sung Ting , Noorulnajwa Diyana Yaacob

Mycelium-based biofoam is a sustainable material derived from the growth of fungal mycelium on lignocellulosic agricultural waste substrate, as it has potential use in a variety of applications. The main objective of this research is to advance the sustainable alternatives for various application by investigating the mycelium growth of the biofoam produced from Pleurotus >lorida and Pleurotus sajor-caju on rice husk substrate, in improving the properties of the biofoam through innovative cold exposure. This study showed P. >lorida can produce mycelium biofoam at a faster rate, 7.022mm/day compared to P. sajor-caju 6.08mm/day). By cold exposure at 0°C and 10°C for 3 hours, every 2 days and 5 days, respectively until the mycelium are fully grown in the substrate, sample exposed to the latter condition for P. >lorida exhibits a faster growth rate at 7.3037 mm/day. However, cold exposure on biofoam produced from P sajor-caju had not improved the mycelium growth rate. Cold exposure samples at 0°C every 5 days and 10°C every 2 days have demonstrated capability in water (103.51%) and oil absorption (143.23%), proving their effectiveness in absorbing pollutants for the purpose of environmental remediation. The FTIR analysis con>irmed the presence of hydrophilic and oleophilic characteristics in the biofoam, indicating its capability to absorb water and oil. By subjecting biofoam to cold exposure, its properties can be altered, broadening its potential applications.

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Effect of different substrates and white Oyster mushroom loading on production of fungal foam

2023 , Noorulnajwa Diyana Yaacob , Hanafi Ismail , Nor Munirah Rohaizad

In this study, agricultural wastes including rice husks, banana leaves and teak leaves were used to produce fungal foam through the cultivation with Pleurotus ostreatus fungi. The fungi are inoculated using different substrates and inoculum loadings. The mechanical properties of the foam produced were analysed. The best substrate and inoculum loading were proposed. Among the three substrates used, banana leave produced the best fungal foam in term of mechanical properties at 10 % w/w inoculum loading. The fungal foam can withstand forces high up to 30458.52 gF and have the resilience and springiness of 0.381 and 0.771, respectively. In summary, banana leave fungal foam is suitable as an alternative to the commercial Styrofoam.

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Thermo-enzymatic hydrolysis of bitter Cassava starch: fundamental and process optimization studies

2010 , Noorulnajwa Diyana Yaacob

Fundamental characterization of cassava starch that will be used in bioethanol production was studied entensively. In the present study, non edible cassava (Manihot esculenta) is used as the raw material for starch, which undergoes enzymatic hydrolysis to produce glucose then precede the fermentation to obtain bioethanol. Proximate analysis of this starch showed that the carbohydrate content is 91.17% while apparent and total amylose are 16.6% and17.1% respectively. Phosphorus and ash showed the lowest value and the moisture content is 10.5%. Nitrogen and Total fat are negligible. By using various analytical equipments, its characteristics were identified. It was found that the root starch has a polyhedric shape by visualizing under SEM and the surface was smooth with no evidence of pores. Under XRD, the pattern shows that the cassava was classified as A-type starch and their gelatinization temperature was high, 89.4°C. Swelling and solubility take place as a result of gelatinization of starch granule. All the fundamental characteristics, gave a good impact for this starch to be used as a raw material in bioethanol industry. Enzymatic hydrolysis of starch from natural sources finds potential application in commercial production of bioethanol. The effects of various process variables were studied for optimum conversion of cassava starch to glucose using α-amylase and amyloglucosidase. Starch is a reserved polysaccharide of plant origin, which cannot be converted to sugar easily. Starch saccharification requires prior gelatinization by heat treatment, liquefaction by α- amylase and conversion to sugars by amyloglucosidase. In order to get higher glucose concentration; liquefaction and saccharification processes must be optimized. Full factorial composite experimental design and central composite design (CCD) were used in the design of experiments and analysis of results. Preliminary study was done to investigate the potential variable for these two processes. The performance of α- amylase in liquefaction was determined by dextrinizing activity (D.A.) while the performance of amyloglucosidase was based on glucose concentration. The optimal condition for liquefaction for 35% cassava starch slurry was obtained by using 0.33% BAN480L in sodium acetate buffer (pH 7) at 85°C for 12.72 min. The optimal conditions for sacharification were found to be at 60.75°C, pH 4.53, using 0.2% AMG300L in 40 min. A model adequacy was very satisfactory, as coefficient of determination were 0.9977 and 0.9795 for liquefaction and sacharification, respectively.

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Tensile, thermal properties, and biodegradability test of paddy straw powder-filled Polyhydroxybutyrate-3-Valerate (PHBV) biocomposites: acrylation pretreatment

2023 , Noorulnajwa Diyana Yaacob , Hanafi Ismail , Sam Sung Ting

The mechanical, thermal, and biodegradability properties of paddy straw powder (PSP)-filled polyhydroxybutyrate-3-valerate (PHBV) biocomposites were investigated. The impacts of chemical alteration of PSP via acrylic acid treatment were examined as well. The outcomes of the study portrayed a decrease in the elongation at break and tensile strength when the filler loading increased; however, the modulus elasticity of composites could be seen to increase. Chemical alteration of PSP via acrylic acid enhanced modulus elasticity of the biocomposites and tensile strength; nevertheless, the elongation at break was decreased. Thermogravimetric analysis demonstrated the enhancement of thermal stability of the biocomposites via PSP compared to neat PHBV. The thermal stability of the biocomposites was positively affected by chemical alteration of PSP. Meanwhile, DSC analysis proved that the melting temperature (T m) of the biocomposites was not altered when the filler was added. Treated biocomposites demonstrated higher crystallinity (30.18%) compared to the untreated composites (26.24%). Biodegradability test showed the strains from both Aspergillus species have the potential to degrade PHBV/PSP biocomposites. The weight loss of biocomposites after undergoing fermentation with Aspergillus fumigatus strain SGE57 and Aspergillus niveus isolate A17 was 2.42% and 3.65%, respectively.

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The effect of chemical treatments on tensile strength and absorption ability of epoxy/natural fibers composites

2020 , Nor Azwin Ahad , M H H Mohamad Rosdi , Noorulnajwa Diyana Yaacob , N H N Che Fauzi , Sabri Zakaria

Natural cellulose from agricultural waste, fruit skin, stalks, and so on is considered as recyclable and may have some potential as oil and water absorbent. Besides it is readily available and environmentally friendly it also inexpensive because they are waste, non-toxic and biodegradable. However, the natural fibres are hydrophilic in nature, so it tends to absorb water. Chemical treatments can usually overcome this problem. Usually, acid and alkali treatments are very popular among researchers. In this study, we focused on seeing the differences in natural treatment on acidic and alkaline using citric acid (vinegar) and sodium bicarbonate (soda) of certain three types of selected fibres. The 24 hrs treatments were studied on coconut coir, banana stem fiber and sugarcane bagasse. The tensile strength has been investigated and compared. All fibers were observed highest tensile strength after treated with alkali compared to acid. Treatment with alkali is more suitable for natural fiber in order to clean the fiber surface, thus help to get better fiber-matrix interaction. These are the reason of highest in tensile strength. Overall, the absorption of oil and seawater depends on the type of fibre itself. All treated fibers tend to absorb more seawater and alkaline treated fibers absorbed more cooking oil. Treated coconut coir have tendency to absorb both medium than other fibers. The type of treatments, will give an effect on the fibres’ surface, remove the impurities and reduce the hydrophilic properties, so that provide decreasing or increasing of cooking oil and seawater uptake.

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Effects of different biomass on the properties of Pleurotus Djamor eco-friendly foam

2023 , Nur Mawaddah Majib , Sam Sung Ting , Lee Boon Beng , Noorulnajwa Diyana Yaacob , Nor Munirah Rohaizad

Plastic waste and polyurethane foam are major sources of pollution that threatens environmentsâ biodiversity. The objective of the study is to create an eco-friendly foam from Pleorotus djamor mycelium, rice husk and sugarcane bagasse. The mushroom industryâ s overabundance of materials, like oyster mushrooms and biomass, has provided an alternative method to make foam that could be beneficial for the environment. The biomass, consisting of rice husk and sugarcane bagasse, both of which are necessary for the production of foam, was evaluated as a substrate. Pleurotus djamor was inoculated on both substrates and test was done on both produced foams. Mechanical tests showed that rice husk foam had higher hardness and less springy than sugarcane bagasse foam. The morphology of both foams was analyzed using a scanning electron microscope (SEM), and the results show that sugarcane bagasse foam is denser than rice husk foam.

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