Ida Idayu Muhammad | Universiti Teknologi Malaysia - UTM (original) (raw)

Papers by Ida Idayu Muhammad

Drying Technology, 2016

ABSTRACT Four different powders of dried lulo (Solanum quitoense Lam.) were obtained by hot air d... more ABSTRACT Four different powders of dried lulo (Solanum quitoense Lam.) were obtained by hot air drying (HD), ultrasound-assisted hot air-drying (HDUS), freeze-drying (FD), and spray-drying (SD). The morphological (SEM) and thermal (TGA–DSC) characterization were made, and some biofunctional properties such as dietary fiber (DF) content and antioxidant capacity (ABTS and DPPH assays) were evaluated. The homogeneous morphology of SD particles was evident from SEM analysis, in contrast to the irregular morphology of the other dried powders. All of the dried lulo powders were thermally stable until 220°C. Although, the initial composition of the mixtures (fruit pulp/maltodextrin DE-20, 2:1, w/w) was the same, some differences on DF content and antioxidant activity were found, indicating that the drying method influenced significantly the chemical composition of powdered products. A higher insoluble dietary fiber (IDF) percentage was found in FD sample; in contrast, a higher in vitro antioxidant capacity values against ABTS and DPPH free radicals were found for HD and SD powders.

Journal of King Saud University - Science

Journal of oleo science, 2018

The impact of microwave roasting on the thermooxidative degradation of perah seed oil (PSO) was e... more The impact of microwave roasting on the thermooxidative degradation of perah seed oil (PSO) was evaluated during heating at a frying temperature (170°C). The roasting resulted significantly lower increment of the values of oxidative indices such as free acidity, peroxide value, p-anisidine, total oxidation (TOTOX), specific extinctions and thiobarbituric acid in oils during heating. The colour L* (lightness) value dropped gradually as the heating time increased up to 12 h, whereas a*(redness) and b* (yellowness) tended to increase. The viscosity and total polar compound in roasted PSO was lower as compared to that in unroasted one at each heating times. The tocol retention was also high in roasted samples throughout the heating period. The relative contents of polyunsaturated fatty acids (PUFAs) were decreased to 94.42% and saturated fatty acids (SFAs) were increased to 110.20% in unroasted sample, after 12 h of heating. On the other hand, in 3 min roasted samples, the relative cont...

Acta scientiarum polonorum. Technologia alimentaria

Perah seed is one of the most underutilized oilseeds, containing high nutritional values and high... more Perah seed is one of the most underutilized oilseeds, containing high nutritional values and high percentage of α-linoleneic acid, which may have a high potential in food and pharmaceutical applica- tions. The main objective of this study was to evaluate the influence of microwave (MW) cooking on the proximate composition and antioxidant activity of perah seeds. In this study, the proximate composition and amygdalin concentration of MW ir- radiated perah seeds were determined. The total phenolic content (TPC), Maillard reaction products (MRPs) and antioxidant activity of methanol (PME), 70% methanol in water (PMW), ethanol (PEE), 70% ethanol in water (PEW) extracts and methanol extract of oil (PMO) were evaluated during MW cooking. The anti- oxidant activity was evaluated using multiple assays, namely DPPH radical scavenging activity, β-Carotene bleaching assay, and reducing power. Microwave cooking did not significantly increase crude lipid and carbohydrate content, and the amount...

Renewable and Sustainable Energy Reviews, 2017

Poly-hydroxyalkanoate was introduced as a bio-based polymer in many countries many years ago, owi... more Poly-hydroxyalkanoate was introduced as a bio-based polymer in many countries many years ago, owing to its biocompatibility and degradation value in the nature. The importance of PHA production of plants and microorganisms is due to its biodegradability and biocompatibility of its structure and materials, which because of this property they will return to the nature and will be replaced with petrochemical plastics. These products were identified as environmentally friendly products in the 21-century. The great potential of PHA as a renewable product, to be produced from industrial waste oils. However, by producing PHA, the environment will be clear of pollutants by using the waste products of factories at first and secondly by circulating the biopolymers to the nature. In the current review, we have focused on PHA production from dairy residues, soybean oil and saponified waste palm oil and some microorganisms such as Pseudomonas, Delftia, Halomonas and E. coli. Amongst different varieties of bacteria Pseudomonas has the highest ability to produce PHA. The global shares of PHA generation in various market segments in 2013 and 2020 shows that capacity production will increase until 2020 and the most production of PHA will be in Asia due to their superior accessibility to feedstock and promising political frame.

The objective of this study were to investigate the reaction of some plants; Lawsonia inermis, St... more The objective of this study were to investigate the reaction of some plants; Lawsonia inermis, Stevia rebaudiana, Brassica oleracea and Allium sativum L towards the diffusivity and color stability. They were extracted and the bioactive compounds were studied. L. inermis was extracted by soxhlet apparatus using ethanol and petroleum ether as solvent whereas ethanol and hexane were used in the extract of S. rebaudiana. All the extract was tested against B. subtilis (Gram-positive bacteria), E. coli (Gram-negative bacteria), A. fumigatus and yeast by disc diffusion method. Both extract showed good inhibitory effects towards the growth of the entire micro organism where the maximum inhibition (3.2Â±0.1 cm) was recorded for L. inermis against B. subtilis. Include in this project was also involves some preliminary observation on the colour stability of anthocyanin in B. oleracea towards the day of storage. Anthocyanins behave like pH indicators as a result of their amphoteric nature. Anthocyanin extracted from B. oleracea are most stable in regards to degradation by thermal and change it colour to red at pH 1 and pH 2, gradually change to purple as the pH is increased to neutral and change to yellow at pH 13 and pH 14. Besides, antibacterial starch (wheat)-based film also has been studied by incorporation of garlic oil from A. sativum L as a natural antibacterial agent. Initially, 10mg of garlic oil incorporated into the starch-based film was tested against two types of food pathogenic bacteria, E. coli and B. subtillis through two types of bacterial inhibition tests, (i) agar plate test and (ii) liquid broth test. From the study, a greater inhibitory effect was observed on B. subtillis.

The aim of this study is to develop biodegradable plastic with natural colouraots as packaging ma... more The aim of this study is to develop biodegradable plastic with natural colouraots as packaging materjal. Blends of anthocyanin and bromocresol purple (BCP) as biological and chemical colourants respectively, tapioca starch, glycerol, polyethylene grafted maleic anhyddde (PE-g-MA), clay nanocomposites and low density polyethylene (LDPE) with different formulation contents for five types of blends were prepared using a lab scale twin screw extruder. A sedes of low densily polyethylene (LDPE) with different blends formulation were developed via blow film extrusion. The moryhology and properties of the blends were evaluated by using a scanning electron microscope (SEM). The dispersion of tapioca starch in the LDPE matrix was homogeneous and mechanical propefiies of the films were improved with the addition of glycerol. The interfacial adhesion between tapioca starch and LDPE was futher improved by the addition of PEg-MA according to the morphological structure sho*n by SEM micrographs, thus enlanced the mechanical propefties of the films. Formulations containing 35 o/o tapioca starch with fairly high concentrations of additives indicate the impoftance of the concentation of starch and the presence of additives on the biodegradabiliry of tapioca starch-LDPE fi lm blends.

Microbial cellulose produced by Acetobacter xylinum is a new type of biopolymer. It has several u... more Microbial cellulose produced by Acetobacter xylinum is a new type of biopolymer. It has several unique properties such as high purity and ultra-fine of fiber network, very high hydrophilic, good mechanical strength, and outstanding shape retention and high crystallinity. This thesis was undertaken to evaluate the production of microbial cellulose in static and shaken culture condition using pineapple waste as the substrate for the fermentation process. Shaken culture technique has been carried out at 80 rpm, 120 rpm and 160 rpm. Optimum condition were fixed at pH 5.0 and temperature of 28Â°C for all the experiments in this research project. From this research, microbial cellulose formation in shaken culture with additional micro particles at 120 rpm is the most suitable as culture medium and the nata produce is more than 70.23% by weight compared to static culture condition. Optimization process for shaken culture with additional micro particles (glass beads) is the best medium culture. Some water-soluble micro particles were added into medium to enhance the production of cellulose in shaken culture condition. With the presence of micro particles, the nata weight increase to 15.19% compared to shaken culture condition. Statistical analysis on experimental design and numerical procedure is the tool in analyzing the yield. Yeast extract and are the most significant factors affect cellulose production. The best selected formulation for preparing the medium culture are yeast extract 6g, sucrose 20g, bactopepton 1.49, KH2PO4 1.08g dan MgSO4 0.06g and nata yield for 441.175g/l.

Arabian Journal for Science and Engineering, 2015

Bacterial cellulose demonstrates unique properties including high mechanical strength, crystallin... more Bacterial cellulose demonstrates unique properties including high mechanical strength, crystallinity and water retention ability that are suitable for industrial applications, such as food, paper manufacturing and pharmaceutical. In this study, Acetobacter xylinum 0416 was cultured in a designed 10-L Rotary Discs Reactor (RDR) to produce bacterial cellulose. The effects of different pH in the range of 3.5-7.5 on the bacterial cellulose production and the bacterial growth were investigated. The highest yield was obtained at pH 5.0 with a total dried weight of 28.3 g, while the lowest yield was obtained at pH 3.5 with a total dried weight of 4.7 g. Results also showed that the dried weight of bacterial cellulose was 60 % higher when the pH of the medium was controlled during the experiments compared with uncontrolled pH. In addition, A. xylinum 0416 growth decreased to around 30 % when pH value dropped from 5.05 to 3.56. The results also proved that the formation of acetic acid as a byproduct caused the pH to drop during fermentation process in 10-L RDR.

Previous researcher had focused to incorporate natural fibers as a part of the construction mater... more Previous researcher had focused to incorporate natural fibers as a part of the construction materials as well as in composites and gave promising results. Natural fibers can be applied in industries in order to promote sustainability features and also in producing practical products in the market. This study was aimed to investigate the effects of incorporating bacterial cellulose derived from fermentation to the mechanical properties of sand-cement block. Blocks samples with dimensions of 100 mm x 100 mm x 100 mm were casted by cement to sand (C:S) ratio of 1:2.5 with a fixed amount of bacterial cellulose fiber by 0.5% (w/w) cement and water to cement (w/c) ratio of 0.7. The compressive strength of sand-cement block incorporated with bacterial cellulose was evaluated for three different periods and the results achieved indicated that the compressive strength ranged between 10.94kN/mm 2 to 15.42kN/mm 2 whilst density showed values of 1748kg/m 3 to 1868kg/m 3 . In conclusion, bacteri...

Microbial cellulose produced by Acetobacter xylinum is an alternative source for plant cellulose ... more Microbial cellulose produced by Acetobacter xylinum is an alternative source for plant cellulose in industrial use. Production of microbial cellulose is receiving great attention since they can be applied in many fields. This research is carried out to study the production of microbial cellulose using Rotary Discs Reactor (RDR) by Acetobacter xylinum bacteria in pineapple waste medium. RDR is a new method developed to enhance the production of microbial cellulose in industrial field because of few advantages: it allows the oxygen enrich air to be supplied continuously, homogenized culture in the medium by rotating discs and less hassle to scale up. This research involved few experimental works including fermentation process, comparison of the production yield from static culture and RDR using similar medium, and glucose analysis. The fermentation process was carried out at room temperature, pH 5.0, rotary speed at 7 rpm and 4 days of fermentation. The variable parameter in this rese...

In this study, the bacteria, P. oleovorans was studied for its ability to produce PHA with glucos... more In this study, the bacteria, P. oleovorans was studied for its ability to produce PHA with glucose, fructose and sucrose as carbon sources that was grown at 25oC. The functional groups of the extracted PHA granules were identified as a C=O group by Fourier Transform Infrared (FTIR) spectroscopy analysis. The drastic absorption band at approximately 1720 cm-1 indicated the stretching vibration of the C=O groups in the PHA polyester. The production optimization of PHA was done by RSM (Response Surface Method) through various growth parameters. After optimization obtained the best condition of productivity in range is glucose 93.4419 g/l. Also the highest PHA production after optimization is 2.28236 g/L with a desirability of 0.986 g/l, meanwhile the highest amount of PHA produced from P. oleovorans was 2.30 g/l.

Jurnal Teknologi, 2014

This study aims to investigate the influence of solvent on the Soxhlet extraction of omega 3 in p... more This study aims to investigate the influence of solvent on the Soxhlet extraction of omega 3 in perah seed oil. Three types of extraction solvent include hexane, hexane: methanol (90:10) and methanol: ethanol (70:30) were investigated. The concentration of extracted omega 3 was measured using Gas chromatography (GC), the colour of extracted oil was classified using colormeter and the total phenolic content (TPC) by Folin-Ciocalteau colorimetry. Based on the total yield extraction of the oil, the result shows that hexane solvent (57.5%) shows better performance compared to hexane-methanol (53.42%) and ethanol-methanol (34.52%). For the omega 3 concentration, hexane-methanol solvent provided highest yield at 1.41g ω-3/g oil followed by ethanol-methanol and hexane at 1.32 ω-3/g oil and 1.15 ω-3/g oil respectively. On the other hand, the extracted oil using hexane as extraction solvent was appeared to be lighter in colour as compared to other solvents studied. In addition, total phenoli...

Key Engineering Materials, 2013

The study aimed to investigate the effect of initial glucose concentration on the microbial cellu... more The study aimed to investigate the effect of initial glucose concentration on the microbial cellulose production using Acetobacter xylinum in a Rotary Discs Reactor (RDR-2 liter volume). The fermentations were carried out for four days at temperature 28°C, initial pH 6.5, and 9 rpm of rotation speed; meanwhile, the initial glucose concentration was manipulated in the range of 0.5-5.0 % (w/v). The cell growth was stimulated using 1.4% (v/v) ethanol in the fermentation medium. The result indicated that 1% (w/v) of initial glucose concentration provided the highest microbial cellulose yield with total wet weight of 296.1657g/l. The increase of initial glucose concentration resulted to the decrease of microbial cellulose yield and greater pH drop after fermentation. It can be conclude that production of microbial cellulose using RDR could produce relatively much higher microbial cellulose with less amounts of glucose in a shorter fermentation period compared to static fermentation due t...

Procedia Chemistry, 2014

This study aimed at the development of antimicrobial (AM) packaging based on wheat starch incorpo... more This study aimed at the development of antimicrobial (AM) packaging based on wheat starch incorporated with chitosan and lauric acid as antimicrobial agents. A series of blends with different ratio of starch, chitosan and lauric acid (S:C:LA) were prepared by casting method. Effects of incorporation of antimicrobial agents into starch-based film were investigated in order to improve the spectrum activity based on measured distributions of inhibitory results. The diffusivity equation approach for describing the antimicrobial effects was also extended to include information about the molecular size of particles in the formed matrices. The Agar Disc Diffusion Assay and Liquid Culture Test measure the distributions of inhibitory effect towards type of bacterial contamination in terms of Gram-positive, Gram-negative and their combination of wider spectrum activity in the blend films. For the first time, the inhibition size distribution resulting from rationing of base polymers and lauric acid as filler in the starch-base film itself was quantified. Spectrum activity of different Gram-stained bacteria as measured by the bacterial growth inhibition, gave surprisingly consistent pattern on rationing of compositions in the film. This indicates that the spectrum activity produced by the antimicrobial components can be related directly to the ratio on blending during film preparation. This phenomenon is proven by dominating of chitosan (S:C:LA ratio 1:9:0.08 to 3:7:0.24) for 48% increase of effective E. coli inhibition (Gram-negative bacteria). More positively, however, it signifies that the affinity of lauric acid towards starch as reported by previous researches indicates relatively unambiguously the ratio required to achieve a constant degree of B. subtilis