Rozaini Abdullah
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Preferred name
Rozaini Abdullah
Official Name
Rozaini, Abdullah
Alternative Name
Abdullah, Rozaini
Abdullah, R.
Main Affiliation
Scopus Author ID
25721634700
Researcher ID
EJS-8999-2022

Research Output
Now showing 1 - 4 of 4
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Publication

The Optimization of Protease Enzyme Extraction from Streblus Asper (Kesinai)

2020-12-18 , Seow Yen Yi , Rozaini Abdullah , Lee Yen Fong , Zarina Zakaria , Huzairy Hassan , Sharifah Zati Hanani Syed Zuber , Mohd Ruslan, Mahfuz Affif

Protease from Streblus asper (Kesinai) is an interesting rennet substitute and yet very few studies had been conducted so far. In the present study, the leaf extract of Kesinai had been discovered to investigate the ability of this milk coagulating enzyme. The development of the optimized conditions for enzyme extraction was analyzed by using Central Composite Design (CCD). The studied factors were ratio of sample to buffer, weight of sample (g) and homogenization time (min). It was found that a 30 g of S. asper leaves sample with the ratio of the sample to buffer of 1:1 and at a mixing rate of 2 minutes established the most desirable conditions for serine proteases extraction from the S. asper leaves sample.

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Parameter effects and optimisation studies on ultrasound-assisted extraction of polyphenolics from mango peel wastes

2024-04 , Noor Amirah Abdul Halim , Mohammed Abdullah Issa , Wan Jing Ooi , Sharifah Zati Hanani Syed Zuber , Nor Fauziah Zainudin , Rozaini Abdullah

In this study, the bioactive properties, such as the total phenolic content (TPC), total flavonoid compound (TFC), and the antioxidant activity of mango peel wastes (MPW) extract were evaluated. The extract was obtained through an ultrasound-assisted extraction (UAE) technique, where 70% ethanol was used as the extractive medium. The main effects of extraction parameters involving the solvent-to-sample ratio, sonication time, and extraction time were studied through a single-factor experiment. It was found that the highest TPC, TFC, and antioxidant activity can be obtained at conditions of 40 mL/g, 30 min, and 50 °C, respectively. Based on the conditions, the TPC was optimised by response surface methodology (RSM), where a significant quadratic regression model with R2 of 0.92 was acquired. The optimum conditions were obtained at 41.49:1 solvent-to-sample ratio, 31.15 min sonication time, and 46.87 °C extraction temperature with a maximum TPC of 25.58 mg GAE/g. Validation experiments were conducted at the optimum extraction condition and successfully yielded a higher TPC yield with an average value of 26.11±2.11 mg GAE/g.

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Kinetic and Isotherm Studies of Malachite Green Adsorption From Aqueous Solution by Calcined Eggshell Treated Orange Peel

2023-06-09 , Chun H.K. , Sharifah Zati Hanani Syed Zuber , Nor Fauziah Zainudin , Noor Amirah Abdul Halim , Rozaini Abdullah , Mohd Qalani Che Kasim

In this work, the ability of eggshell treated orange peel as a low-cost adsorbent to remove malachite green (MG) dye from an aqueous solution was investigated. The eggshell treated orange peel was characterized by using Fourier transform infrared (FTIR) spectroscopy analysis. From the FTIR analysis, the functional group that might be involved in the adsorption process was found to be carboxylic acid and alcohol. The effect of contact time, initial dye concentration and adsorbent dosage were also investigated by using batch adsorption mode. The results showed that the percentage of dye removal increased with the increase of contact time and the process attained equilibrium within 140 minutes with the highest percentage of MG dye removal was 98%. The percentage of dye removal was also found to increase with the increase of initial dye concentration and adsorbent dosage. The experimental result showed that 0.1 g eggshell treated orange peel was able to remove 98% of MG dye while about 99% of MG dye was removed for 250 mg/L of dye concentration. The adsorption isotherm data were well fitted to the Langmuir isotherm model with the qmax of 31.45 mg g-1. Meanwhile, the kinetic data was best presented by the pseudo-second-order model with R2> 0.99.

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Screening and optimization biosynthesis of iron nanoparticle using watermelon rind as reducing and stabilizing agent

2023 , Rozaini Abdullah , Nurul Fazliana Ahmad , Noraini Razali , Sharifah Zati Hanani Syed Zuber

This study aimed to screen and optimized the biosynthesis of iron nanoparticles (FeNPs) by utilizing watermelon rind extract (WMR) as the reducing and stabilizing agent. To determine the significant characteristics in terms of attaining a high yield of FeNPs, the screening of the factor influencing the biosynthesis FeNPs was then analyzed using a two-level factorial design with Design-Expert Software version 11. The factors were reactant concentration, incubation time, and incubation temperature, as well as the response, which was the yield of FeNPs. This response refers to the main target of this study which is to improve the yield of production FeNPs. The findings indicated that among all the factors investigated, reactant concentration, incubation time, and incubation temperature were the significant contributing factors impacting the yield of FeNPs with a p-value < 0.05. The experimental domain factors were effectively collected from the ANOVA analysis with a good linear regression; thus, these data could be augmented and to be used as the optimized condition. The optimal condition suggested by the Design Expert for the biosynthesis of FeNPs was 1 M of reactant concentration, 3 h of incubation time, and 30 °C of incubation temperature.

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