Aishah Bujang | Universiti Teknologi Mara (original) (raw)

Papers by Aishah Bujang

Malaysian Journal of Analytical Science, 2016

A lot of effort is needed to diverse food products utilisation of cassava leaves which are regard... more A lot of effort is needed to diverse food products utilisation of cassava leaves which are regarded as famine reserve crop for food security. The objective of this study was to evaluate protein, fibre and sensory of meat floss incorporated with different amount of cassava leaves (CL) (25%, 50%, 75% and 100%). Its stability during storage was monitored for 84 days in terms of lipid oxidation through peroxide value (PV) and formation of thiobarbituric acid reactive substance (TBARS). The results showed that protein content decreases while fibre content increases with the increase amount of CL substitution. No significant difference (p>0.05) was obtained in preference based on sensory attributes of texture, taste and overall acceptability of control floss with 100% CL substituted floss. At initial storage duration (up to day 30), similar linear increase in PV was observed among all formulations; however, further storage showed slower increment by the 100% CL substituted floss. Similarly, faster formation of TBARS was shown by control floss while the lowest values was shown by 100% CL floss. This study showed that CL is a suitable alternative for meat and also proved that total substitution of CL was well accepted and has longer storage stability compared to meat floss.

Graphical abstract Abstract The aim of this study was to determine the nutrient and anti-nutrient... more Graphical abstract Abstract The aim of this study was to determine the nutrient and anti-nutrient composition of six varieties of cassava leaf namely Medan,

Graphical abstract Abstract This study focus on the stability of natural pigment from Melastoma m... more Graphical abstract Abstract This study focus on the stability of natural pigment from Melastoma malabathricum fruit in pink guava juice at 30°C and 60°C storage temperature. Analysis on the content of vitamin C, total phenolic content, lycopene, anthocyanin and color were conducted for 30 days. In general, the results showed higher reduction in all quality parameters at higher storage temperature. Freshly made PGJ contains 86.55±5.18 mg/100mL of vitamin C, 5.36±0.27 mg/L of lycopene, 933.50± 60.11 mgGAE/L of total phenolic content (TPC) and 1.36±0.32 mg/L of total monomeric anthocyanin. At day 30 of storage, vitamin C was reduced to 56.4% and 9.4% at 30 o C and 60 o C respectively. Total monomeric anthocyanins content was reduced to 38.2% and 7.2% at 30 o C and 60°C respectively. Total phenolic content remained at day 30 was 12.1% and 7.5% at 30 o C and 60 o C respectively. While lycopene was found to be least affected by storage temperature compared to other quality attributes analyzed. The total color difference was increased drastically at 60 o C between days 0 to 5 while linear increase was observed at 30 o C storage. These studies provide useful information on the availability of the health beneficial compounds in fruit juice as well as their stability as natural food colourant during storage.

Quality degradation is normally judge by monitoring independently the loss of a certain quality a... more Quality degradation is normally judge by monitoring independently the loss of a certain quality attribute during storage. However, the rate of degradation for each of the quality attributes present in a food product is not the same. This study focus on deterioration of vitamin C, lycopene, total phenolics and antioxidant activity of ready-to-drink pink guava juice (PGJ) during storage at elevated temperatures. Kinetic order, rate constant (k), activation energy (Ea) and temperature coefficient (Q 10) of the degradation were derived by applying Arrhenius equation. The results obtained showed that freshly made PGJ contain 39.79±2.18 mg/100 mL of vitamin C, 3.17±0.27 mg/L of lycopene, 28.08±4.11 mgGAE/100 mL of total phenolic content (TPC) and 13.20±1.91 mMTE/100 mL of ferric reducing antioxidant power (FRAP). All quality attributes measured in this study showed zero-order kinetic reaction. The results also showed that FRAP has the highest Ea of 49.52 KJ/mol and Q 10 of 1.80, followed by vitamin C (Ea=41.49 KJ/mol; Q 10 =1.64), lycopene (Ea=31.75 KJ/mol; Q 10 =1.46), and lastly TPC (Ea=14.11 KJ/mol; Q 10 =1.18). The predicted total depletion of each quality attribute at refrigerated storage (5 o C) were 266 days for antioxidant activity, 158 days for vitamin C and lycopene, and 63 days for total phenolics. This study provide useful information on the degradation rate and availability of health beneficial and bioactive compounds present in fruit juice beverage during storage.

There are many factors influencing the stability and color variation of natural colorant anthocya... more There are many factors influencing the stability and color variation of natural colorant anthocyanin and pH is among the most significant factor. This study aims to determine the stability of the anthocyanins in freeze-dried Hibiscus sabdariffa, Melastoma malabathricum and Ipomoea batatas in various acidic pH (pH 2.0, 2.5, 3.0, 3.5, 4.0 and 4.5). Total monomeric anthocyanin, degradation index, color density and percent polymeric color were analyzed to determine anthocyanins degradation and their color variations. Among the samples, H.sabdariffa contain the highest monomeric anthocyanins (163.3 mg/L) followed by M. malabathricum (49.9 mg/L) and the lowest is I.batatas (13.8 mg/L). Monomeric anthocyanins from I.batatas were found to be very stable and not affected by changes in pH than in H. sabdariffa and M. malabathricum. However, degradation index (DI) of H. sabdariffa was the lowest with value of 0.365 ± 0.049 at pH 3.5. The lowest percentage of polymeric color (4.94 ± 0.64) was also shown by H. sabdariffa at pH 2.5 and maintained a deep red color with increasing pH indicating higher color stability compared to M. malabathricum and I. batatas. Overall, natural pigment in H. sabdariffa was found to be the most stable in both monomeric anthocyanin content and chromaticity properties. These results provided information that will further proven the potential usage of H. sabdariffa, M. malabathricum and I. batatas as natural coloring agents to replace the synthetic colorant in food and beverage industries.

Advanced Materials Research, 2013

This study aims to evaluate the influence of solvent acids and glycerol as plasticizer on the ant... more This study aims to evaluate the influence of solvent acids and glycerol as plasticizer on the antimicrobial and physical properties of chitosan films. Three types of acids were used in the same concentration, e.g. 1% acetic acid, 1% citric acid and 1% lactic acid whereas glycerol was fixed on 10% (w/w). In terms of barrier properties, chitosan film obtained by citric acid as solvent showed the lowest water vapour transmission rate (WVTR) followed by chitosan film prepared with lactic acid and acetic acid. Concerning mechanical properties, chitosan film prepared with acetic acid exhibited the highest tensile strength and the lowest percentage elongation. The expected result was obtained where plasticized chitosan films had higher percentage elongation than the unplasticized one. In this study, disc and well diffusion method were used against bacteria, yeast and fungi to characterize antimicrobial activity of the obtained films. When the disc diffusion method was used, all of chitosan films showed an inhibition activity against E. coli, B. cereus and S. aureus whereas no inhibition against Penicillium sp. and Candida sp except chitosan film prepared with acetic acid that showed inhibition against Candida sp. The same result was observed by using well diffusion method with the exception of chitosan solutions prepared with acetic acid solution where they also showed inhibition activity against Penicillium sp. and Candida sp.

Sains Malaysiana

Fermentation of legumes is a well-recognised preserving method that not only diversifies the sens... more Fermentation of legumes is a well-recognised preserving method that not only diversifies the sensory attributes of the legume-based foods but also enhances its nutritional value. This study aimed to evaluate the changes in amino acids content of soybean, garbanzo bean and groundnut upon pre-treatments (soaking and steaming) and fermentation times (18, 24 and 30 h). The amino acids analysis was performed with a HPLC system using AccQTag method. The results obtained showed that raw soybean contain the highest amount of essential and non-essential amino acids followed by raw garbanzo bean and groundnut. After the soaking process, the amount of amino acids obtained was significantly increased in all three legumes. However, the steaming process was found to cause significant decrease in the amino acids content. After the steaming process, the legumes were inoculated with Rhizopus oligosporus and incubated at 30 o C and 65% RH. At 18 h of fermentation time, the amount of total amino acids...

A two-factor three-level Faced-Centered Cube (FCD) Design consisting of thirteen runs was employe... more A two-factor three-level Faced-Centered Cube (FCD) Design consisting of thirteen runs was employed to optimize the preparation of granular cold water-soluble (GCWS) sago starch using alcoholic-alkaline treatment. The variables studied were ethanol concentration (40%, 50% and 60%) and the ratio of sodium hydroxide (1.5 M): starch (1:1, 2:1 and 3:1 at 100g db starch). Response Surface Methodology (RSM) was used to evaluate the effect of process variables and their interactions on the apparent amylose content, cold water solubility and swelling power, apparent viscosity and the granule mean particle size of the GCWS starches produced. In general, sodium hydroxide (NaOH) exhibited more pronounced effect on most of the responses studied; it was found significantly increased the amylase leaching, cold water solubility and swelling power (p<0.05) of the products. On the other hand, ethanol restricted excessive swelling by decreasing the cold water solubility (p<0.05). At high NaOH co...

Malaysian Journal of Analytical Science, 2016

A lot of effort is needed to diverse food products utilisation of cassava leaves which are regard... more A lot of effort is needed to diverse food products utilisation of cassava leaves which are regarded as famine reserve crop for food security. The objective of this study was to evaluate protein, fibre and sensory of meat floss incorporated with different amount of cassava leaves (CL) (25%, 50%, 75% and 100%). Its stability during storage was monitored for 84 days in terms of lipid oxidation through peroxide value (PV) and formation of thiobarbituric acid reactive substance (TBARS). The results showed that protein content decreases while fibre content increases with the increase amount of CL substitution. No significant difference (p>0.05) was obtained in preference based on sensory attributes of texture, taste and overall acceptability of control floss with 100% CL substituted floss. At initial storage duration (up to day 30), similar linear increase in PV was observed among all formulations; however, further storage showed slower increment by the 100% CL substituted floss. Similarly, faster formation of TBARS was shown by control floss while the lowest values was shown by 100% CL floss. This study showed that CL is a suitable alternative for meat and also proved that total substitution of CL was well accepted and has longer storage stability compared to meat floss.

Graphical abstract Abstract The aim of this study was to determine the nutrient and anti-nutrient... more Graphical abstract Abstract The aim of this study was to determine the nutrient and anti-nutrient composition of six varieties of cassava leaf namely Medan,

Graphical abstract Abstract This study focus on the stability of natural pigment from Melastoma m... more Graphical abstract Abstract This study focus on the stability of natural pigment from Melastoma malabathricum fruit in pink guava juice at 30°C and 60°C storage temperature. Analysis on the content of vitamin C, total phenolic content, lycopene, anthocyanin and color were conducted for 30 days. In general, the results showed higher reduction in all quality parameters at higher storage temperature. Freshly made PGJ contains 86.55±5.18 mg/100mL of vitamin C, 5.36±0.27 mg/L of lycopene, 933.50± 60.11 mgGAE/L of total phenolic content (TPC) and 1.36±0.32 mg/L of total monomeric anthocyanin. At day 30 of storage, vitamin C was reduced to 56.4% and 9.4% at 30 o C and 60 o C respectively. Total monomeric anthocyanins content was reduced to 38.2% and 7.2% at 30 o C and 60°C respectively. Total phenolic content remained at day 30 was 12.1% and 7.5% at 30 o C and 60 o C respectively. While lycopene was found to be least affected by storage temperature compared to other quality attributes analyzed. The total color difference was increased drastically at 60 o C between days 0 to 5 while linear increase was observed at 30 o C storage. These studies provide useful information on the availability of the health beneficial compounds in fruit juice as well as their stability as natural food colourant during storage.

Quality degradation is normally judge by monitoring independently the loss of a certain quality a... more Quality degradation is normally judge by monitoring independently the loss of a certain quality attribute during storage. However, the rate of degradation for each of the quality attributes present in a food product is not the same. This study focus on deterioration of vitamin C, lycopene, total phenolics and antioxidant activity of ready-to-drink pink guava juice (PGJ) during storage at elevated temperatures. Kinetic order, rate constant (k), activation energy (Ea) and temperature coefficient (Q 10) of the degradation were derived by applying Arrhenius equation. The results obtained showed that freshly made PGJ contain 39.79±2.18 mg/100 mL of vitamin C, 3.17±0.27 mg/L of lycopene, 28.08±4.11 mgGAE/100 mL of total phenolic content (TPC) and 13.20±1.91 mMTE/100 mL of ferric reducing antioxidant power (FRAP). All quality attributes measured in this study showed zero-order kinetic reaction. The results also showed that FRAP has the highest Ea of 49.52 KJ/mol and Q 10 of 1.80, followed by vitamin C (Ea=41.49 KJ/mol; Q 10 =1.64), lycopene (Ea=31.75 KJ/mol; Q 10 =1.46), and lastly TPC (Ea=14.11 KJ/mol; Q 10 =1.18). The predicted total depletion of each quality attribute at refrigerated storage (5 o C) were 266 days for antioxidant activity, 158 days for vitamin C and lycopene, and 63 days for total phenolics. This study provide useful information on the degradation rate and availability of health beneficial and bioactive compounds present in fruit juice beverage during storage.

There are many factors influencing the stability and color variation of natural colorant anthocya... more There are many factors influencing the stability and color variation of natural colorant anthocyanin and pH is among the most significant factor. This study aims to determine the stability of the anthocyanins in freeze-dried Hibiscus sabdariffa, Melastoma malabathricum and Ipomoea batatas in various acidic pH (pH 2.0, 2.5, 3.0, 3.5, 4.0 and 4.5). Total monomeric anthocyanin, degradation index, color density and percent polymeric color were analyzed to determine anthocyanins degradation and their color variations. Among the samples, H.sabdariffa contain the highest monomeric anthocyanins (163.3 mg/L) followed by M. malabathricum (49.9 mg/L) and the lowest is I.batatas (13.8 mg/L). Monomeric anthocyanins from I.batatas were found to be very stable and not affected by changes in pH than in H. sabdariffa and M. malabathricum. However, degradation index (DI) of H. sabdariffa was the lowest with value of 0.365 ± 0.049 at pH 3.5. The lowest percentage of polymeric color (4.94 ± 0.64) was also shown by H. sabdariffa at pH 2.5 and maintained a deep red color with increasing pH indicating higher color stability compared to M. malabathricum and I. batatas. Overall, natural pigment in H. sabdariffa was found to be the most stable in both monomeric anthocyanin content and chromaticity properties. These results provided information that will further proven the potential usage of H. sabdariffa, M. malabathricum and I. batatas as natural coloring agents to replace the synthetic colorant in food and beverage industries.

Advanced Materials Research, 2013

This study aims to evaluate the influence of solvent acids and glycerol as plasticizer on the ant... more This study aims to evaluate the influence of solvent acids and glycerol as plasticizer on the antimicrobial and physical properties of chitosan films. Three types of acids were used in the same concentration, e.g. 1% acetic acid, 1% citric acid and 1% lactic acid whereas glycerol was fixed on 10% (w/w). In terms of barrier properties, chitosan film obtained by citric acid as solvent showed the lowest water vapour transmission rate (WVTR) followed by chitosan film prepared with lactic acid and acetic acid. Concerning mechanical properties, chitosan film prepared with acetic acid exhibited the highest tensile strength and the lowest percentage elongation. The expected result was obtained where plasticized chitosan films had higher percentage elongation than the unplasticized one. In this study, disc and well diffusion method were used against bacteria, yeast and fungi to characterize antimicrobial activity of the obtained films. When the disc diffusion method was used, all of chitosan films showed an inhibition activity against E. coli, B. cereus and S. aureus whereas no inhibition against Penicillium sp. and Candida sp except chitosan film prepared with acetic acid that showed inhibition against Candida sp. The same result was observed by using well diffusion method with the exception of chitosan solutions prepared with acetic acid solution where they also showed inhibition activity against Penicillium sp. and Candida sp.

Sains Malaysiana

Fermentation of legumes is a well-recognised preserving method that not only diversifies the sens... more Fermentation of legumes is a well-recognised preserving method that not only diversifies the sensory attributes of the legume-based foods but also enhances its nutritional value. This study aimed to evaluate the changes in amino acids content of soybean, garbanzo bean and groundnut upon pre-treatments (soaking and steaming) and fermentation times (18, 24 and 30 h). The amino acids analysis was performed with a HPLC system using AccQTag method. The results obtained showed that raw soybean contain the highest amount of essential and non-essential amino acids followed by raw garbanzo bean and groundnut. After the soaking process, the amount of amino acids obtained was significantly increased in all three legumes. However, the steaming process was found to cause significant decrease in the amino acids content. After the steaming process, the legumes were inoculated with Rhizopus oligosporus and incubated at 30 o C and 65% RH. At 18 h of fermentation time, the amount of total amino acids...

A two-factor three-level Faced-Centered Cube (FCD) Design consisting of thirteen runs was employe... more A two-factor three-level Faced-Centered Cube (FCD) Design consisting of thirteen runs was employed to optimize the preparation of granular cold water-soluble (GCWS) sago starch using alcoholic-alkaline treatment. The variables studied were ethanol concentration (40%, 50% and 60%) and the ratio of sodium hydroxide (1.5 M): starch (1:1, 2:1 and 3:1 at 100g db starch). Response Surface Methodology (RSM) was used to evaluate the effect of process variables and their interactions on the apparent amylose content, cold water solubility and swelling power, apparent viscosity and the granule mean particle size of the GCWS starches produced. In general, sodium hydroxide (NaOH) exhibited more pronounced effect on most of the responses studied; it was found significantly increased the amylase leaching, cold water solubility and swelling power (p<0.05) of the products. On the other hand, ethanol restricted excessive swelling by decreasing the cold water solubility (p<0.05). At high NaOH co...