Displaying publications 1 - 20 of 223 in total

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  1. Lo SK, Cheong LZ, Arifin N, Tan CP, Long K, Yusoff MS, et al.
    J Agric Food Chem, 2007 Jul 11;55(14):5595-603.
    PMID: 17571899
    Diacylglycerol (DAG) and triacylglycerol (TAG) as responses on optimization of DAG production using a dual response approach of response surface methodology were investigated. This approach takes the molecular equilibrium of DAG into account and allows for the optimization of reaction conditions to achieve maximum DAG and minimum TAG yields. The esterification reaction was optimized with four factors using a central composite rotatable design. The following optimized conditions yielded 48 wt % DAG and 14 wt % TAG: reaction temperature of 66.29 degrees C, enzyme dosage of 4 wt %, fatty acid/glycerol molar ratio of 2.14, and reaction time of 4.14 h. Similar results were achieved when the process was scaled up to a 10 kg production in a pilot packed-bed enzyme reactor. Lipozyme RM IM did not show any significant activity losses or changes in fatty acid selectivity on DAG synthesis during the 10 pilot productions. However, lipozyme RM IM displayed higher selectivity toward the production of oleic acid-enriched DAG. The purity of DAG oil after purification was 92 wt %.
  2. Loo JL, Lai OM, Long K, Ghazali HM
    World J Microbiol Biotechnol, 2007 Dec;23(12):1771-8.
    PMID: 27517833 DOI: 10.1007/s11274-007-9427-2
    Mycelium-bound lipase (MBL) was prepared using a strain of Geotrichum candidum isolated from local soil. At the time of maximum lipase activity (54 h), the mycelia to which the lipase was bound were harvested by filtration and centrifugation. Dry MBL was prepared by lyophilizing the mycelia obtained. The yield of MBL was 3.66 g/l with a protein content of 44.11 mg/g. The lipase activity and specific lipase activity were 22.59 and 510 U/g protein, respectively. The moisture content of the MBL was 3.85%. The activity of free (extracellular) lipase in the culture supernatant (after removal of mycelia) was less than 0.2 U/ml. The MBL showed selectivity for oleic acid over palmitic acid during hydrolysis of palm olein, indicating that the lipase from G. candidum displayed high substrate selectivity for unsaturated fatty acid containing a cis-9 double bond, even in crude form. This unique specificity of MBL could be a direct, simple and inexpensive way in the fats and oil industry for the selective hydrolysis or transesterification of cis-9 fatty acid residues in natural triacylglycerols.
  3. Abdulkarim, S.M., Lai, O.M., Muhammad, S.K.S., Long, K., Ghazali, H.M.
    MyJurnal
    Solvent-extracted Moringa oleifera seed oil was transesterified using immobilized lipase (Lipozyme IM 60) (Novozymes Bagsvaerd Denmark) at 1% (w/w) concentration, shaken at 60oC and 200 rpm for up to 24h. After transesterification, the oil was fractionated with acetone at -18oC and without acetone at 10oC to obtain two fractions, stearin and olein fractions. Incubation of the transesterified oil at 10oC for 24 h resulted in the formation of fat crystals, which settled at the bottom of the flask in sample transesterified for 24 h, while the control (0 h) sample became rather viscous with fat crystals in suspension. Transesterification resulted in a change in the triacylglycerol (TAG) profile of the oil, which in turn affected its solid fat content (SFC) and thermal behavior. The SFC value at 0oC after 24 h of reaction was 10.35% and significantly (P
  4. Leong WF, Che Man YB, Lai OM, Long K, Misran M, Tan CP
    J Agric Food Chem, 2009 Sep 23;57(18):8426-33.
    PMID: 19694442 DOI: 10.1021/jf901853y
    The purpose of this study was to optimize the parameters involved in the production of water-soluble phytosterol microemulsions for use in the food industry. In this study, response surface methodology (RSM) was employed to model and optimize four of the processing parameters, namely, the number of cycles of high-pressure homogenization (1-9 cycles), the pressure used for high-pressure homogenization (100-500 bar), the evaporation temperature (30-70 degrees C), and the concentration ratio of microemulsions (1-5). All responses-particle size (PS), polydispersity index (PDI), and percent ethanol residual (%ER)-were well fit by a reduced cubic model obtained by multiple regression after manual elimination. The coefficient of determination (R(2)) and absolute average deviation (AAD) value for PS, PDI, and %ER were 0.9628 and 0.5398%, 0.9953 and 0.7077%, and 0.9989 and 1.0457%, respectively. The optimized processing parameters were 4.88 (approximately 5) homogenization cycles, homogenization pressure of 400 bar, evaporation temperature of 44.5 degrees C, and concentration ratio of microemulsions of 2.34 cycles (approximately 2 cycles) of high-pressure homogenization. The corresponding responses for the optimized preparation condition were a minimal particle size of 328 nm, minimal polydispersity index of 0.159, and <0.1% of ethanol residual. The chi-square test verified the model, whereby the experimental values of PS, PDI, and %ER agreed with the predicted values at a 0.05 level of significance.
  5. Arifin N, Peng KS, Long K, Ping TC, Affandi Yusoff MS, Nor Aini I, et al.
    J Sci Food Agric, 2010 Apr 30;90(6):943-8.
    PMID: 20355133 DOI: 10.1002/jsfa.3886
    This study aims to investigate the textural properties and sensory qualities of cookies made from medium- and long-chain triacylglycerol (MLCT)-enriched margarines. Margarine with formulations of MLCT:palm olein:palm stearin, 60:30:10 and 70:20:10, were selected to produce cookies. The textural properties of cookies were determined using a texture analyser. Quantitative descriptive analysis (QDA) and acceptance test were carried out to describe the attributes and to evaluate the degree of liking of cookies, respectively.
  6. Cheong LZ, Tan CP, Long K, Affandi Yusoff MS, Lai OM
    J Sci Food Agric, 2010 Oct;90(13):2310-7.
    PMID: 20661900 DOI: 10.1002/jsfa.4088
    Diacylglycerol (DAG), which has health-enhancing properties, is sometimes added to bakery shortening to produce baked products with enhanced physical functionality. Nevertheless, the quantity present is often too little to exert any positive healthful effects. This research aimed to produce bakery shortenings containing significant amounts of palm diacyglycerol (PDG). Physicochemical, textural and viscoelastic properties of the PDG bakery shortenings during 3 months storage were evaluated and compared with those of commercial bakery shortening (CS).
  7. Marikkar JM, Ghazali HM, Long K
    J Oleo Sci, 2010;59(1):7-14.
    PMID: 20032594
    This study was to characterize the seed fat from Madhuca longifolia known as Mee fat and its solid and liquid fractions with the objective of distinguishing them. A sample of Mee fat was partitioned into solid and liquid fractions using acetone as the solvent medium. The isolated fractions were compared to the native Mee fat sample with respect to various physico-chemical parameters using standard chemical methods as well as instrumental techniques such as, gas liquid chromatography (GLC), reversed-phase high performance liquid chromatography (RP-HPLC), and differential scanning calorimetry (DSC). Basic analyses indicated that there were wide variations between the native sample and its fractions with respect to iodine value (IV), and slip melting point (SMP). The cloud point (CP) of the liquid fraction was found to be 10.5 degrees C. Fatty acid compositional analyses showed that the proportion of saturated fatty acids (SFA) such as palmitic and stearic went up in the high-melting fraction (HMF) while in low-melting fraction (LMF) the proportion of unsaturated fatty acid (USFA) such as oleic and lenoleic increased. According to the HPLC analyses, Mee fat had a tiacyl glycerol (TAG) sequence similar to that of palm oil. After fractionation, the solid and liquid fractions obtained were found to have TAG profiles very much different from the native sample. Thermal analyses by DSC showed that Mee fat had two-widely separated high and low melting thermal transitions, a feature which was beneficial for the effective separation of solid and liquid fractions. The thermal profiles displayed by the fractions were clearly distinguishable from that of the native sample.
  8. Arifin, N., Cheong, L.Z., Koh, S.P., Long, K., Tan, C.P., Yusoff, M.S.A., et al.
    ASM Science Journal, 2010;4(2):113-122.
    MyJurnal
    Several binary and ternary medium- and long-chain triacylglycerol (MLCT)-enriched margarine formulations were examined for their solid fat content, heating profile, polymorphism and textural properties. MLCT feedstock was produced through enzymatic esterification of capric and stearic acids with glycerol. The binary formulations were produced by mixing MLCT feedstock blend (40%–90%) and palm olein (10%–60%) with 10% increments (w/w). Solid fat profiles of commercial margarines were used as a reference to determine the suitability of the formulations for margarine production. The solid fat content of the binary formulations of MO 82 and MO 91 (M, MLCT, O, palm olein) were similar to the commercial margarines at 25°C which met the basic requirement for efficient dough consistency. Ternary formulations using reduced MLCT feedstock blend proportion (from 80%–90% to 60%–70%) were also developed. The reduction of MLCT feedstock blend was
    done as it had the highest production cost (3USD/kg) in comparison to palm olein (0.77USD/kg) and palm stearin (0.7USD/kg). The proportions of 5%–15% of palm stearin were substituted with palm olein in MO 64 and MO 73 (M, MLCT; O, palm olein) formulations with 5% increment (w/w). As a result, MOS 702010 and MOS 603010 (M, MLCT; O, palm olein; S, palm stearin) margarine formulations showed similar SFC % to the commercial margarines at 25ºC. These formulations were subsequently chosen to produce margarines. The onset melting and complete melting points of MLCT-enriched margarine formulations were high (51.04ºC –57.93ºC) due to the presence of a high amount of long chain saturated fatty acids. Most of the formulations showed β΄- crystals. MOS 702010 was selected as the best formulation due to values for textural parameters comparable (P
  9. Yanty NA, Marikkar JM, Man YB, Long K
    J Oleo Sci, 2011;60(7):333-8.
    PMID: 21701095
    Lard being an edible fat could be used in different forms in food systems. In this study, composition and thermal analysis of lard stearin (LS) and lard olein (LO) were undertaken to determine some common parameters which would enable their detection in food. A sample of native lard was partitioned into LS and LO using acetone as solvent and the fractions were compared to the original sample with respect to basic physico-chemical parameters, fatty acid and triacylglycerol (TAG) composition, and thermal characteristics. Although LS and LO displayed wider variations in basic physico-chemical parameters, thermal properties and solidification behavior, they do possess some common characteristic features with regard to composition. In spite of the proportional differences in the major fatty acids, both LS and LO are found to possess extremely high amount of palmitic (C16:0) acid at the sn-2 positions of their TAG molecules. Similar to native lard, both LS and LO contained approximately equal proportions of TAG molecules namely, linoleoyl-palmitoyl-oleoyl glycerol (LPO) and dioleoyl-palmitoyl glycerol (OPO). Hence, the calculated LPO/OPO ratio for LS and LO are comparably similar to that of native lard.
  10. Zakaria ZA, Somchit MN, Mat Jais AM, Teh LK, Salleh MZ, Long K
    Med Princ Pract, 2011;20(3):231-6.
    PMID: 21454992 DOI: 10.1159/000323756
    The present study was carried out to investigate the antinociceptive and anti-inflammatory activities of virgin coconut oil (VCO) produced by the Malaysian Agriculture Research and Development Institute (MARDI) using various in vivo models.
  11. Koh, S. P., Long, K., Yusoff, M. S. A., Arifin, N.
    MyJurnal
    The potential use of medium- and long-chain triacylglycerols (MLCT) oil blends in food applications such as frying oil and salad dressings were investigated. The frying strength of palm-based MLCT oil with different antioxidants under deep frying conditions was assessed. Palm-based MLCT oil showed better thermal-resistant oxidative strength than refined, bleached and deodorized (RBD) palm olein throughout the five consecutive days of frying. Sensory evaluation and rancidity assessment on fried chips showed no significant differences (P > 0.05) between chips fried in RBD palm olein and palm-based MLCT oil. MLCT-based salad dressings treated with different antioxidants showed similar rheological behaviors as compared to soybean based salad dressings. The overall quality of the physical appearance and organoleptic acceptability based on quantitative descriptive analysis showed no significant differences (P > 0.05) in all salad dressings. These findings indicated that MLCT-based oil blends can be used as healthy functional oil for daily consumption.
  12. Zakaria ZA, Rofiee MS, Somchit MN, Zuraini A, Sulaiman MR, Teh LK, et al.
    PMID: 21318140 DOI: 10.1155/2011/142739
    The present study aims to determine the hepatoprotective effect of MARDI-produced virgin coconut oils, prepared by dried- or fermented-processed methods, using the paracetamol-induced liver damage in rats. Liver injury induced by 3 g/kg paracetamol increased the liver weight per 100 g bodyweight indicating liver damage. Histological observation also confirms liver damage indicated by the presence of inflammations and necrosis on the respective liver section. Interestingly, pretreatment of the rats with 10, but not 1 and 5, mL/kg of both VCOs significantly (P < .05) reduced the liver damage caused by the administration of paracetamol, which is further confirmed by the histological findings. In conclusion, VCO possessed hepatoprotective effect that requires further in-depth study.
  13. Yeap SK, Mohd Ali N, Mohd Yusof H, Alitheen NB, Beh BK, Ho WY, et al.
    J Biomed Biotechnol, 2012;2012:285430.
    PMID: 23091343 DOI: 10.1155/2012/285430
    Mung bean was reported as a potential antidiabetic agent while fermented food has been proposed as one of the major contributors that can reduce the risk of diabetes in Asian populations. In this study, we have compared the normoglycemic effect, glucose-induced hyperglycemic effect, and alloxan-induced hyperglycemic effect of fermented and nonfermented mung bean extracts. Our results showed that fermented mung bean extracts did not induce hypoglycemic effect on normal mice but significantly reduced the blood sugar levels of glucose- and alloxan-induced hyperglycemic mice. The serum levels of cholesterol, triglyceride (TG), and low-density lipoprotein (LDL) were also lowered while insulin secretion and antioxidant level as measured by malonaldehyde (MDA) assays were significantly improved in the plasma of the fermented mung bean-treated group in alloxan-induced hyperglycemic mouse. These results indicated that fermentation using Mardi Rhizopus sp. strain 5351 inoculums could enhance the antihyperglycemic and the antioxidant effects of mung bean in alloxan-treated mice. The improvement in the antihyperglycemic effect may also be contributed by the increased content of GABA and the free amino acid that are present in the fermented mung bean extracts.
  14. Manaf YN, Marikkar JM, Long K, Ghazali HM
    J Oleo Sci, 2013;62(6):335-43.
    PMID: 23728324
    The seeds (6.9±0.2% by weight of fruit) of the red-skin rambutan (Nephelium lappaceum L.) contain a considerable amount of crude fat (38.0±4.36%) and thus, the aim of the study was to determine the physico-chemical properties of this fat for potential applications. The iodine and saponification values, and unsaponifiable matter and free fatty acid contents of the seed fat were 50.27 g I2/100g fat, 182.1 mg KOH/g fat, 0.8% and 2.1%, respectively. The fat is pale yellow with a Lovibond color index of 3.1Y+1.1R. The fatty acid profile indicates an almost equal proportion of saturated (49.1%) and unsaturated (50.9%) fatty acids, where oleic (42.0%) and arachidic (34.3%) acids were the most dominant fatty acids. It also contained small amounts of stearic (8.0%), palmitic (4.6%), gadoleic (5.9%), linoleic (2.2%), behenic (2.1%) palmitoleic (0.7%) myristic (0.1%) and erucic (0.1%) acids. HPLC analysis showed that the fat comprised mainly unknown triacylglycerols (TAG) with high retention times indicating they have higher carbon numbers compared with many vegetable oils. The fat has melting and cooling points of 44.2°C and -42.5°C, respectively, making it a semi-solid at room temperature. The solid content at 0°C was 53.5% and the fat melted completely at 40°C. z-Nose analysis showed that the presence of high levels of volatile compounds in red-skin rambutan seed and seed fat.
  15. Mohd Ali N, Mohd Yusof H, Long K, Yeap SK, Ho WY, Beh BK, et al.
    Biomed Res Int, 2013;2013:693613.
    PMID: 23484140 DOI: 10.1155/2013/693613
    Mung bean is a hepatoprotective agent in dietary supplements. Fermentation and germination processes are well recognized to enhance the nutritional values especially the concentration of active compounds such as amino acids and GABA of various foods. In this study, antioxidant and hepatoprotective effects of freeze-dried mung bean and amino-acid- and GABA-enriched germinated and fermented mung bean aqueous extracts were compared. Liver superoxide dismutase (SOD), malondialdehyde (MDA), ferric reducing antioxidant power (FRAP), nitric oxide (NO) levels, and serum biochemical profile such as aspartate transaminase (AST), alanine transaminase (ALT), triglycerides (TG), and cholesterol and histopathological changes were examined for the antioxidant and hepatoprotective effects of these treatments. Germinated and fermented mung bean have recorded an increase of 27.9 and 7.3 times of GABA and 8.7 and 13.2 times of amino acid improvement, respectively, as compared to normal mung bean. Besides, improvement of antioxidant levels, serum markers, and NO level associated with better histopathological evaluation indicated that these extracts could promote effective recovery from hepatocyte damage. These results suggested that freeze-dried, germinated, and fermented mung bean aqueous extracts enriched with amino acids and GABA possessed better hepatoprotective effect as compared to normal mung bean.
  16. Nyam, K.L., Wong, M.M., Long, K., Tan, C.P.
    MyJurnal
    With the concern of adverse effects of lipid oxidation on food deterioration and human health, the antioxidant activities of kenaf seed extracts (KSE), roselle seed extracts (RSE) and roselle extracts (RE) were evaluated by comparing its oxidative stability in refined, bleached & deodorised (RBD) sunflower oils with that of in synthetic antioxidant, BHA. Established methods such as peroxide values (PV), p-anisidine values (AV), TOTOX values, free fatty acids (FFA), iodine values (IV), total phenolic contents (TPC), conjugated dienes (CD) and conjugated triene (CT) were employed to assess the extent of oil deterioration. During 24 days storage, consensus was accomplished based on the results assessed by PV, TOTOX, CD, CT, IV and TPC at which the antioxidant activities of KSE, RSE and RE were better than BHA. Surprisingly, the results obtained by AV and FFA assays showed the reversed. Among the extracts, RSE exhibited the best antioxidant activities. These suggest that KSE, RSE and RE may be used as potential source of natural antioxidants in the application of food industry to prevent lipid oxidation.
  17. Mohd Yusof H, Ali NM, Yeap SK, Ho WY, Beh BK, Koh SP, et al.
    PMID: 24058369 DOI: 10.1155/2013/274274
    Recently, soybean tempeh has received great attention due to many advantages such as higher nutritional value, lower production cost, and shorter fermentation time. In this study, the in vivo hepatoprotective and antioxidant effects of nutrient enriched soybean tempeh (NESTE) were determined. NESTE fermentation process which involved anaerobic incubation was previously proclaimed to increase the content of amino acids and antioxidant properties remarkably. The evaluation of histological sections, serum biochemical markers (aspartate aminotransferase (AST), alanine aminotransferase (ALT), and cholesterol and triglycerides (TG)), liver immune response level (nitric oxide (NO)) and liver antioxidant level (superoxide dismutase (SOD), ferric reducing antioxidant power (FRAP), and malondialdehyde (MDA)) was conducted in order to compare the effects of nonfermented soybean extract (SBE) and fermented soybean extract (NESTE) on alcohol-induced liver damage in mice. Results demonstrated that 1000 mg/kg of NESTE can significantly reduce the levels of AST, ALT, cholesterol, TG, MDA, and NO. On the other hand, it also raised the level of SOD and FRAP. Furthermore, the histological examination on 1000 mg/kg NESTE treatment group showed that this extract was capable of recovering the damaged hepatocytes to their normal structures. Thus, it can be concluded that NESTE produced through fermentation process was able to enhance hepatoprotective and antioxidant effects in vivo.
  18. Yeap SK, Mohd Yusof H, Mohamad NE, Beh BK, Ho WY, Ali NM, et al.
    PMID: 23710232 DOI: 10.1155/2013/708464
    Mung bean has been reported to have antioxidant, cytotoxic, and immunomodulatory effects in vitro. Fermented products are reported to have enhanced immunomodulation and cancer chemopreventive effects. In this study, fermented mung bean treatments in vivo were studied by monitoring tumor development, spleen immunity, serum cytokine (interleukin 2 and interferon gamma) levels, and spleen/tumor antioxidant levels after injection with low and high risk 4T1 breast cancer cells. Pretreatment with fermented mung bean was associated with delayed tumor formation in low risk mice. Furthermore, this treatment was connected with higher serum anticancer cytokine levels, spleen T cell populations, splenocyte cytotoxicity, and spleen/tumor antioxidant levels. Histopathological evaluation of fermented mung bean treated tumor revealed lower event of mitotic division. On the other hand, antioxidant and nitric oxide levels that were significantly increased in the untreated mice were inhibited in the fermented mung bean treated groups. These results suggested that fermented mung bean has potential cancer chemoprevention effects through the stimulation of immunity, lipid peroxidation, and anti-inflammation.
  19. Wong YH, Tan WY, Tan CP, Long K, Nyam KL
    Asian Pac J Trop Biomed, 2014 May;4(Suppl 1):S510-5.
    PMID: 25183141 DOI: 10.12980/APJTB.4.2014C1090
    To examine the cytotoxic properties of both the kenaf (Hibiscus cannabinus L.) seed extract and kenaf seed oil on human cervical cancer, human breast cancer, human colon cancer and human lung cancer cell lines.
  20. Loo JL, Khoramnia A, Lai OM, Long K, Ghazali HM
    Molecules, 2014 Jun 23;19(6):8556-70.
    PMID: 24959682 DOI: 10.3390/molecules19068556
    Mycelium-bound lipase (MBL), from a locally isolated Geotrichum candidum strain, was produced and characterized as a natural immobilized lipase. A time course study of its lipolytic activity in 1 L liquid broth revealed the maximum MBL activity at 4 h for mycelium cells harvested after 54 h. The yield and specific activity of MBL were 3.87 g/L dry weight and 508.33 U/g protein, respectively, while less than 0.2 U/mL lipase activity was detected in the culture supernatant. Prolonged incubation caused release of the bound lipase into the growth medium. The growth pattern of G. candidum, and production and properties of MBL were not affected by the scale. The stability of mycelia harboring lipase (MBL), harvested and lyophilized after 54 h, studied at 4 °C depicted a loss of 4.3% and 30% in MBL activity after 1 and 8 months, while the activity of free lipase was totally lost after 14 days of storage. The MBL from G. candidum displayed high substrate selectivity for unsaturated fatty acids containing a cis-9 double bond, even in crude form. This unique specificity of MBL could be a direct, simple and inexpensive way in the fats and oil industry for the selective hydrolysis or transesterification of cis-9 fatty acid residues in natural triacylglycerols.
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