Displaying all 15 publications

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  1. Normah, I.
    MyJurnal
    Gelatin from sutchi catfish (Pangasius hypophthalmus) skin was extracted and applied in the preparation of gummy in order to determine the suitability of sutchi catfish gelatin in gummy production. The skin was subjected to pre-treatment in the following sequence; 0.8M NaCl, 0.19 N NaOH followed by 0.12 N acetic acid prior to 12 hours extraction in distilled water at 50oC. The physicochemical characteristics of sutchi catfish gelatin was analysed and compared with the commercial bovine gelatin. Gummy added with sutchi catfish gelatin was also compared with gummy added with commercial gelatin. Analysis comprises of yield, gel strength, setting point and setting time, amino acid composition, texture profile analysis and sensory evaluation. The extraction resulted in 14.47% yield of gelatin. Sutchi catfish gelatin showed higher gel strength value (360.86 g) compared to the commercial gelatin (217.37 g) which is in accordance with proline content. Texture profile analysis showed that gummies prepared using sutchi catfish gelatin had significantly higher (p
  2. Normah, I., Noorasma, M.
    MyJurnal
    Mud clam (Polymesoda erosa) hydrolysate (AH) was produced by hydrolysis for 2 hrs using alcalase 2.4L at pH 8.5, 60°C and 3% enzyme-substrate ratio. D-xylose and L-cysteine or D-xylose were added into the hydrolysate and heated at 120°C for 2 hrs to produce the Maillard reaction products (MRPs) labelled as AH-mx or AH-x, respectively. Amino acids, volatile compounds and sensory characteristics of AH and MRPs were evaluated. Amino acids analysis showed that monosodium glutamate (MSG)-like amino acids amount was higher while 2-piperidinone volatile compound that contributes to bitterness was lower in MRPs than AH. Furthermore, sensory results showed that MRPs had more intense umami and less fishy taste compared to AH. Therefore, it was discovered that Maillard reaction improved the flavor of mud clam hydrolysate.
  3. Normah, I., Noorasma, M.
    MyJurnal
    Physicochemical properties of mud clam (Polymesoda erosa) hydrolysate produced using two microbial enzymes; alcalase and flavourzyme were determined. Hydrolysis using alcalase at 20.28% degree of hydrolysis (DH) resulted in 25.06 % yield and 45.37% protein while flavourzyme hydrolysis showed 22.93 % DH, 46.67 % protein and 30.68 % yield. Both hydrolysates were yellowish. Better emulsifying properties, foaming properties and water and oil holding capacity were exhibited by flavourzyme hydrolysate compared to the alcalase hydrolysate. However, in terms of amino acid composition, alcalase hydrolysate contained higher amino acid composition (75.06%) than flavourzyme hydrolysate (62.37%). The study suggested that mud clam hydrolysate had the potential to be used in food formulations for human consumption.
  4. Normah, I., Maidzatul Afiqah, M.
    MyJurnal
    Fish waste is a major by-product of fish processing industries. Sin croaker (Johniecop sina) waste could be a valuable source of collagen and utilizing such waste will reduce pollution associated with fish processing industries. The objective of this study is to determine the physico-chemical characteristics of sin croaker waste collagen extracted using 0.5 M acetic acid as a function of extraction time which were 3 and 5 days. The extracted collagens were also compared with the commercial collagen. Results showed that extraction at the duration of 3 and 5 days produced 2.74 and 3.35% yields of collagen, respectively. Both collagens were most soluble at low pH (pH 1-2) and low salt concentration (2% NaCl). Differential Scanning Calorimetry (DSC) analysis showed that the extracted collagen had good thermal stability as it denatured at 31.31°C and 32.10°C, respectively. Commercial collagen denatured at 30.60°C. Sodium dodecyl sulfate gel electrophoresis (SDS-PAGE) indicated that both collagens are of Type I due to the presence of α1, α2 chains, β and γ components. Commercial collagen showed only smeared band. Thus, it is concluded that sin croaker collagens extracted at the duration of 3 and 5 days exhibited similar characteristics and are of equally good quality.
  5. Normah, I., Nur Anati, J.
    MyJurnal
    Threadfin bream (Nemipterus japonicas) muscle was hydrolysed using protease extracted from
    bilimbi (Averrhoa bilimbi L.) fruit. This study was performed in order to compare the efficiency of bilimbi protease in producing threadfin bream protein hydrolysate with the commercial protease; alcalase 2.4 L. Initially, protease was extracted and then purified using 40% ammonium sulfate precipitation method. The proteolytic activity of the crude extract and purified protease was determined. Precipitation using 40% ammonium sulfate resulted in bilimbi protease specific activity of 2.36 U/mg and 23.13% recovery. Threadfin bream hydrolysate was prepared based on the pH-stat method by hydrolysis for 2 hrs. Hydrolysis using bilimbi protease produced 34.76% degree of hydrolysis (DH) and 3.75% yield while hydrolysis using alcalase resulted in 86.6% DH with 22.78% yield. Alcalase hydrolysate showed higher solubility than bilimbi protease hydrolysate at pH 7 with 70.87 and 32.16% solubility, respectively. Results also showed that protein content of threadfin bream hydrolysate produced using alcalase was higher (86.86%) than those produced using bilimbi protease (22.12%). However, both hydrolysates showed low moisture content between 3.93 to 7.00%. The molecular weight distribution analysis using SDS–PAGE indicated the distribution of smaller peptides especially in alcalase hydrolysate. Overall, the results showed that alcalase is more efficient enzyme choice than bilimbi protease for preparing threadfin bream hydrolysates. However, both hydrolysates could play an important role thus contribute to the food industry.
  6. Normah, I., Nurdalila Diyana, M.R.
    MyJurnal
    This study was conducted to evaluate umami taste in protein hydrolysate produced from green mussel (Perna viridis) by hydrolysing with flavorzyme at pH 8, enzyme substrate ratio (E/S) 3% with or without the presence of 0.4% sodium tripolyphosphate (STPP) and 1.5% NaCI. Degree of hydrolysis (DH), yield, amino acid compositions, molecular weight distribution and sensory evaluation were determined. The highest DH (23.18%), darkest color and highest yield (8.34%) were recorded for hydrolysate produced in the presence of both STPP and NaCI. Electrophoresis analysis showed the presence of protein bands between 10 to 70 kDa where hydrolysate with addition of STPP and NaCI had bands with lower intensities. Amino acids which contribute to the umami taste such as glutamic acid, glycine and aspartic acid were higher in hydrolysate produced with STPP and NaCI addition. The hydrolysate has lesser fishy odor and flavor than those produced with only in the presence of flavorzyme and was also rated with highest score for all the five basic tastes including bitterness. However, the score for bitterness was still lower than the reference solutions. Therefore, green mussel hydrolysate produced in this study has a good potential as a food flavorant.
  7. Normah, I., Nurul Fasihah, R.
    MyJurnal
    Angelwing clam (Pholas orientalis) hydrolysate was prepared by hydrolysis using bromelain. The hydrolysate named as bromelain hydrolysate (BH) was then treated with β-cyclodextrin in the ratio of 1:0.8 (v/w) by physical mixing and kneading methods producing the physical mixed hydrolysate (PMH) and kneaded method hydrolysate (KMH), respectively. The masking effect of β-cyclodextrin on bitterness was evaluated based on sensory analysis, amino acid analysis and determination of flavor compound by gas chromatography- mass spectrometry (GC-MS) and field emission scanning electron microscope (FESEM). Sensory analysis showed that KMH has least bitter taste compared to BH. Amino acids analysis showed that hydrophobic amino acids content that contributed to the bitter taste were lower in KMH and PMH compared to BH. GC-MS analysis also showed that benzothiazole compounds were present in KMH. The absence of benzene, 1-phenyl-4-2-(2-cyano-2-phenylethyl) in KMH and PMH indicated that phenylalanine in BH had been masked by β-cyclodextrin. FESEM showed that the new solid phase formed by kneading method has a crystal structure which was completely different from the original morphology of BH and β-cyclodextrin. Therefore, the bitterness in BH had successfully been masked by β-cyclodextrin, thus indicates its potential to be used as food ingredient..
  8. Normah, I., Cheow, C.S., Chong, C.L.
    MyJurnal
    Diacylglycerol at 1 or 6% was added into refined bleached and deodorized palm oil (RBDPO) and crystallized from the melt in a thermally controlled water bath at 22°C for 90 min. Slurries were withdrawn after 5, 15, 30, 60 and 90 min of crystallization for solid fat content (SFC) and crystal morphology studies. Crystallization was also performed in a similar manner using a Labmax reactor connected to a FBRM detector to obtain the information on crystal count and size distribution during crystallization. SFC of the slurries increased with increase in crystallization time up to a certain level followed by a plateau. SFC of RBDPO added with DAG was also higher with the increase in percentage of DAG added and no induction time was observed to initiate crystallization in RBDPO added with DAG. The addition of DAG caused rapid crystallization of RBDPO as observed by enhance nucleation and larger crystal size with increase in the percentages of DAG added.
  9. Normah, I., Nur-Hani Suryati, M.Z.
    MyJurnal
    Collagen was isolated from threadfin bream (Nemipterus japonicas) waste (mixture of scale and fin) by using 0.5 M citric acid or calamansi juice (Citrofortunella microcarpa) for 12 and 24 hrs at 4°C. The physico-chemical characteristics of the collagens were then compared with the commercial collagen. Shorter extraction time (12 hrs) and extraction using calamansi juice resulted in higher yield. The yield was 22% (12 hrs) and 20.37% (24 hrs) for collagen extracted using calamansi juice and 8.3% (12 hrs) and 6.9% (24 hrs) for collagen extracted using citric acid. Collagen extracted using calamansi juice were light yellow (L = 93.70, a = -1.84, b = 13.44) while citric acid collagens were white (L = 94.82, a = 0.31, b = 0.20). Sensory evaluation on odor recognition test showed that collagen extracted with calamansi juice has a pleasant
    natural fragrance which is sweet citrus. Electrophoresis profile indicated that the collagen were of type I comprising of α1 and α2 chains. Threadfin bream collagen contained higher amount of imino acids proline (254.72 to 275.50/1000 residues) and hydroxyproline (7.56 to 13.50/1000 residues) than commercial collagen which is 21.25 and 5.16/1000 residues, respectively. Maximum transition temperature (Tmax) falls within a close range for all the collagens ranging from 24.81 to 25.91°C. Calamansi juice collagens were more viscous compared to others. The extraction of threadfin bream collagen for 12 hrs using calamansi juice generally leads to collagen characterised by pleasant odor, reasonably high yield and more viscous. Therefore, natural source such as calamansi juice could be an alternative medium for collagen extraction.
  10. Normah, I., Cheow, C.S., Chong, C.L.
    MyJurnal
    Refined bleached and deodorized palm oil (RBDPO) was crystallized from the melt in a thermally controlled water bath at 14 and 22°C for 90 min. Slurries were withdrawn after 5, 15, 30, 60 and 90 min of crystallization for crystal morphology studies. Crystallization was also performed in a similar manner using a Labmax reactor connected to a FBRM detector to obtain the information on crystal count and size distribution during crystallization. Based on the shape of the crystals viewed under the microscope, all crystals appeared as needle shaped spherulitic β´- form at both crystallization temperatures studied. Crystals were slightly larger with increase in crystallization time and at higher crystallization temperature (22°C). Crystals size range between 4.34 to 22.29µm. FBRM recorded high count of crystals with increased in crystallization time and at lower temperature (14°C).
  11. Normah, I., Nor Aryan Nabila, N.A.
    Science Letters, 2019;13(1):42-54.
    MyJurnal
    Protease comprises the class of enzymes that are most used worldwide, accounting for 60% of the world total enzyme production. This study was carried out to determine the proteolytic activity of protease extracted from torpedo scad fish (Megalaspis cordyla) viscera, and to determine the optimum pH and ammonium sulphate concentration for the extraction and purification of the extracted visceral protease. The combination of optimum condition for pH and ammonium sulphate concentration was optimized using the Response Surface Methodology (RSM). The crude enzyme extracts are then precipitated in ammonium sulphate followed by dialysis and gel filtration chromatography where the proteolytic activity was studied. The concentration of ammonium sulphate used ranged from 40-80% and pH used for extraction was between 6-9. The enzyme showed the highest proteolytic activity at pH 9 and 80% ammonium sulphate concentration matching with RSM suggested condition. The proteolytic activity obtained under this condition was 445U. The total activity of the crude extract, ammonium sulphate precipitation, and dialyzed proteases were 820, 680 and 425U, respectively. The viscera contained 15.87% protein. Thus, the optimum condition for extraction and purification of protease from torpedo scad fish viscera were at pH 9 with 80% ammonium sulphate concentration, respectively resulting in high proteolytic activity.
  12. Nadzirah, K.Z., Zainal, S., Noriham, A., Normah, I.
    MyJurnal
    Bromelain is one of the vegetal proteases found in pineapple plant. It has numerous applications in food and pharmaceuticals. This review discussed different bromelain purification techniques which will assist in determining the effect of processing conditions on the purification efficacy. There are four purification techniques to be discussed, namely; reverse micellar system, aqueous two phase extraction, cation exchange chromatography and ammonium sulphate precipitation. Of the four techniques, cation exchange chromatography had shown the best bromelain purification technique with purification fold of 10.0 followed by reverse micellar system containing CTAB/ isooctane/ hexanol/ butanol, ATPE containing PEG polymer, ammonium sulphate precipitation and ATPE containing PEO-PPO-PEO with purification fold of 5.2, 4.0, 2.81 and 1.25, respectively.
  13. Normah, I., Siti Hafsah, M.S., Nurul Izzaira, A.
    MyJurnal
    Green mussel (Perna viridis) was hydrolysed with alcalase under two different conditions consisting of pH7, E/S5% or pH 9, E/S 3% at 60°C for two hours. Hydrolysis at pH 9, E/S3% resulted in a higher degree of hydrolysis (DH) than pH7, E/S5% with degree of hydrolysis of 37.00% and 28.33%, respectively. The green mussel hydrolysates were characterized by molecular weight of
  14. Wan Saidatul Syida, W.K., Normah, I., Noriham, A., Mohd Yusuf, M.
    MyJurnal
    Processing of soybeans to other products and consumption of soy products is increasing worldwide mainly due to acclaimed health benefits. Processing can alter soybean sensory appeal, nutritive value and potentially affect consumer health. Rhizopus oligosporus was used to ferment soybean for 3 days. The tempeh flour (TF) was produced form tempeh while defatted tempeh flour (DTF) was then produced from TF by immersing in hexane solvent while soy protein isolate (SPI) was prepared from DTF by using alkali and acid followed by neutralization treatment. In this study, nutritional properties and amino acid content of tempeh, TF, DTF and SPI were determined. Therefore, the objective of this study is was to evaluate the effect of each treatment on the chemical composition and amino acid content for all the samples. The results showed that the nutritional properties (total ash, moisture, crude fat, total carbohydrate and crude fibre) were reduced significantly (p < 0.05) except for protein content. Protein content was significantly (p < 0.05) increased by 50.5% in SPI. For amino acid content, the results obtained showed that SPI contain highest amount of essential and non-essential amino acid followed by DTF, Tempeh and TF. Glutamic acid was found to be the highest amino acid component in all samples. The evaluation from the results showed that SPI can be considered as potential functional food ingredients.
  15. Nadzirah, K.Z., Zainal, S., Noriham, A., Normah, I., Siti Roha, A.M., Nadya, H.
    MyJurnal
    The aim of this study is to determine colour changes during storage and physico- chemical properties of peel, core and crown extracts of pineapple variety N36 for maturity indices of 1, 2 and 3. The L* (lightness), a* (redness) and b* (yellowness) values for peels increased significantly (p ≤ 0.05) at each maturity stage during seven days storage. pH of pineapple peel, core and crown extracts were in the range of 3.24 to 3.84. The titratable acidity, percentage of pulp and Total Soluble Solid (TSS) of pineapple peel, core and crown extracts were in the range of 0.16 to 0.36%, 1.37 to 2.91% and 1.4 to 5.3˚Brix, respectively. Fructose and glucose contents were significantly highest (p ≤ 0.05) in pineapple core extract followed by pineapple peel extract and pineapple crown extract for maturity index 2. Significant difference (p ≤ 0.05) was found in sucrose content between pineapple core and peel extracts with 8.92% and 3.87%, respectively for maturity index 3. However, sucrose was not detected in pineapple crown extract. Pineapple core extract was significantly higher (p ≤ 0.05) amount of total sugar content compared to pineapple peel and crown extracts for all maturity indices.
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