Displaying publications 81 - 100 of 245 in total

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  1. Lee YY, Tang TK, Phuah ET, Karim NA, Alwi SM, Lai OM
    J Food Sci Technol, 2015 Feb;52(2):685-96.
    PMID: 25694677 DOI: 10.1007/s13197-013-1065-0
    Structured lipid such as medium-and long-chain triacylglycerol (MLCT) is claimed to be able to suppress body fat accumulation and be used to manage obesity. Response surface methodology (RSM) with four factors and three levels (+1,0,-1) faced centered composite design (FCCD) was employed for optimization of the enzymatic interesterification conditions of palm-based MLCT (P-MLCT) production. The effect of the four variables namely: substrate ratio palm kernel oil: palm oil, PKO:PO (40:60-100:0 w/w), temperature (50-70 °C), reaction time (0.5-7.5 h) and enzyme load (5-15 % w/w) on the P-MLCT yield (%) and by products (%) produced were investigated. The responses were determined via acylglycerol composition obtained from high performance liquid chromatography. Well-fitted models were successfully established for both responses: P-MLCT yield (R (2) = 0.9979) and by-products (R (2) = 0.9892). The P-MLCT yield was significantly (P  0.05). Substrate ratio PKO: PO (100:0 w/w) gave the highest yield of P-MLCT (61 %). Nonetheless, substrate ratio of PKO: PO (90:10w/w) was chosen to improve the fatty acid composition of the P-MLCT. The optimized conditions for substrate ratio PKO: PO (90:10 w/w) was 7.26 h, 50 °C and 5 % (w/w) Lipozyme TLIM lipase, which managed to give 60 % yields of P-MLCT. Up scaled results in stirred tank batch reactor gave similar yields as lab scale. A 20 % increase in P-MLCT yield was obtained via RSM. The effect of enzymatic interesterification on the physicochemical properties of PKO:PO (90:10 w/w) were also studied. Thermoprofile showed that the P-MLCT oil melted below body temperature of 37 °C.
  2. Lee YY, Tang TK, Ab Karim NA, Alitheen NB, Lai OM
    Food Funct, 2014 Jan;5(1):57-64.
    PMID: 24247642 DOI: 10.1039/c3fo60358j
    Structured lipid medium- and long-chain triacylglycerols (MLCT) are claimed to be able to manage obesity. The present study investigated the body fat influence of enzymatically interesterifed palm-based medium- and long-chain triacylglycerols (P-MLCT) on diet-induced obesity (DIO) C57BL/6J mice compared with commercial MLCT oil (C-MLCT) and a control, which was the non enzymatically modified palm kernel and palm oil blend (PKO-PO blend). It also investigated the low fat and high fat effects of P-MLCT. DIO C57BL/6J mice were fed ad libitum with low fat (7%) and high fat (30%) experimental diets for 8 weeks before being sacrificed to obtain blood serum for analysis. From the results, there is a trend that P-MLCT fed mice were found to have the lowest body weight, body weight gain, total fat pad accumulation (perirenal, retroperitoneal, epididymal and mesenteric), total triglyceride levels and efficiency in controlling blood glucose level, compared with C-MLCT and the PKO-PO blend in both low fat and high fat diets. Nevertheless, the PKO-PO blend and P-MLCT caused significantly (P < 0.05) higher total cholesterol levels compared to C-MLCT. P-MLCT present in low fat and high fat dosage were shown to be able to suppress body fat accumulation. This effect is more prominent with the low fat dosage.
  3. Latip RA, Lee YY, Tang TK, Phuah ET, Tan CP, Lai OM
    Food Chem, 2013 Dec 15;141(4):3938-46.
    PMID: 23993569 DOI: 10.1016/j.foodchem.2013.05.114
    The stearin fraction of palm-based diacylglycerol (PDAGS) was produced from dry fractionation of palm-based diacylglycerol (PDAG). Bakery shortening blends were produced by mixing PDAGS with either palm mid fraction, PMF (PDAGS/PMF), palm olein, POL(PDAGS/POL) or sunflower oil, SFO (PDAGS/SFO) at PDAGS molar fraction of XPDAGS=0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%. The physicochemical results obtained indicated that C16:0 and C18:1 were the dominant fatty acids for PDAGS/PMF and PDAGS/POL, while C18:1 and C18:2 were dominant in the PDAGS/SFO mixtures. SMP and SFC of the PDAGS were reduced with the addition of PMF, POL and SFO. Binary mixtures of PDAGS/PMF had better structural compatibility and full miscibility with each other. PDAGS/PMF and PDAGS/SFO crystallised in β'+β polymorphs in the presence of 0.4-0.5% PDAGS while PDAGS/POL resulted in β polymorphs crystal. The results gave indication that PDAGS: PMF at 50%:50% and 60%:40% (w/w) were the most suitable fat blend to be used as bakery shortening.
  4. Ab Latip R, Lee YY, Tang TK, Phuah ET, Lee CM, Tan CP, et al.
    PeerJ, 2013;1:e72.
    PMID: 23682348 DOI: 10.7717/peerj.72
    Fractionation which separates the olein (liquid) and stearin (solid) fractions of oil is used to modify the physicochemical properties of fats in order to extend its applications. Studies showed that the properties of fractionated end products can be affected by fractionation processing conditions. In the present study, dry fractionation of palm-based diacylglycerol (PDAG) was performed at different: cooling rates (0.05, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0°C/min), end-crystallisation temperatures (30, 35, 40, 45 and 50°C) and agitation speeds (30, 50, 70, 90 and 110 rpm) to determine the effect of these parameters on the properties and yield of the solid and liquid portions. To determine the physicochemical properties of olein and stearin fraction: Iodine value (IV), fatty acid composition (FAC), acylglycerol composition, slip melting point (SMP), solid fat content (SFC), thermal behaviour tests were carried out. Fractionation of PDAG fat changes the chemical composition of liquid and solid fractions. In terms of FAC, the major fatty acid in olein and stearin fractions were oleic (C18:1) and palmitic (C16:0) respectively. Acylglycerol composition showed that olein and stearin fractions is concentrated with TAG and DAG respectively. Crystallization temperature, cooling rate and agitation speed does not affect the IV, SFC, melting and cooling properties of the stearin fraction. The stearin fraction was only affected by cooling rate which changes its SMP. On the other hand, olein fraction was affected by crystallization temperature and cooling rate but not agitation speed which caused changes in IV, SMP, SFC, melting and crystallization behavior. Increase in both the crystallization temperature and cooling rate caused a reduction of IV, increment of the SFC, SMP, melting and crystallization behaviour of olein fraction and vice versa. The fractionated stearin part melted above 65°C while the olein melted at 40°C. SMP in olein fraction also reduced to a range of 26 to 44°C while SMP of stearin fractions increased to (60-62°C) compared to PDAG.
  5. Lee YY, Tang TK, Lai OM
    J Food Sci, 2012 Aug;77(8):R137-44.
    PMID: 22748075 DOI: 10.1111/j.1750-3841.2012.02793.x
    Medium- and long-chain triacylglycerol (MLCT) is a modified lipid containing medium- chain (C6-C12) and long-chain fatty acids (C14-C24) in the same triacylglycerol (TAG) molecule. It can be produced either through enzymatic (with 1,3 specific or nonspecific enzyme) or chemical methods. The specialty of this structured lipid is that it is metabolized differently compared to conventional fats and oils, which can lead to a reduction of fat accumulation in the body. Therefore, it can be used for obesity management. It also contains nutritional properties that can be used to treat metabolic problems. This review will discuss on the health benefits of MLCT, its production methods especially via enzymatic processes and its applications in food industries.
  6. Karim NA, Noor AM, Lee YY, Lai OM
    J Food Sci, 2015 Dec;80(12):C2678-85.
    PMID: 26523850 DOI: 10.1111/1750-3841.13119
    The oxidative and thermal stability of low diglycerides palm oil produced via silica treatment (sPO) and enzymatic treatment (ePO) compared with standard quality palm oil (SQ) and premium quality palm oil (PQ) was investigated. Both of the oils displayed better oxidative stability compared with SQ as well as significantly higher (P < 0.05) thermal resistance and oxidative strength than SQ and PQ due to lower amounts of partial glycerides. Although the initial induction periods (IPs) of sPO and ePO were significantly lower compared with SQ and PQ, both the oils showed slower drops in their IP values. The darkening effect after frying was significantly (P < 0.05) slower in sPO compared with SQ, PQ, and ePO. Besides, there is no difference p > 0.05 in the rate of FFA formation between sPO and PQ. The anisidine value and peroxide values were lowest in sPO, followed by ePO, PQ, and SQ.
  7. Lee YY, Tang TK, Phuah ET, Tan CP, Wang Y, Li Y, et al.
    Crit Rev Food Sci Nutr, 2020;60(15):2509-2525.
    PMID: 31418288 DOI: 10.1080/10408398.2019.1650001
    Diacylglycerol (DAG) is a world leading anti-obesity functional cooking oil synthesized via structural modification of conventional fats and oils. DAG exits in three stereoisomers namely sn-1,2-DAG, sn-1,3-DAG, and sn-2,3-DAG. DAG particularly sn-1,3-DAG demonstrated to have the potential in suppressing body fat accumulation and lowering postprandial serum triacylglycerol, cholesterol and glucose level. DAG also showed to improve bone health. This is attributed to DAG structure itself that caused it to absorb and digest via different metabolic pathway than conventional fats and oils. With its purported health benefits, many studies attempt to enzymatically or chemically synthesis DAG through various routes. DAG has also received wide attention as low calorie fat substitute and has been incorporated into various food matrixes. Despite being claimed as healthy cooking oil the safety of DAG still remained uncertain. DAG was banned from sale as it was found to contain probable carcinogen glycidol fatty acid esters. The article aims to provide a comprehensive and latest review of DAG emphasizing on its structure and properties, safety and regulation, process developments, metabolism and beneficial health attributes as well as its applications in the food industry.
  8. Lee YY, Tang TK, Phuah ET, Alitheen NB, Tan CP, Lai OM
    J Sci Food Agric, 2017 Mar;97(5):1379-1385.
    PMID: 27801514 DOI: 10.1002/jsfa.8124
    Non-enzymatic browning has been a wide and interesting research area in the food industry, ranging from the complexity of the reaction to its applications in the food industry as well as its ever-debatable health effects. This review provides a new perspective to the Maillard reaction apart from its ubiquitous function in enhancing food flavour, taste and appearance. It focuses on the recent application of Maillard reaction products as an inexpensive and excellent source of emulsifiers as well as superior encapsulating matrices for the entrapment of bioactive compounds. Additionally, it will also discuss the latest approaches employed to perform the Maillard reaction as well as several important reaction parameters that need to be taken into consideration when conducting the Maillard reaction. © 2016 Society of Chemical Industry.
  9. Lee YY, Tang TK, Phuah ET, Karim NAA, Alitheen NBM, Tan CP, et al.
    Food Res Int, 2018 01;103:200-207.
    PMID: 29389606 DOI: 10.1016/j.foodres.2017.10.022
    Medium-and-Long Chain Triacylglycerol (MLCT) is a type of structured lipid that is made up of medium chain, MCFA (C8-C12) and long chain, LCFA (C16-C22) fatty acid. Studies claimed that consumption of MLCT has the potential in reducing visceral fat accumulation as compared to long chain triacylglycerol, LCT. This is mainly attributed to the rapid metabolism of MCFA as compared to LCFA. Our study was designed to compare the anti-obesity effects of a enzymatically interesterified MLCT (E-MLCT) with physical blend of palm kernel and palm oil (B-PKOPO) having similar fatty acid composition and a commercial MLCT (C-MLCT) made of rapeseed/soybean oil on Diet Induced Obesity (DIO) C57BL/6J mice for a period of four months in low fat, LF (7%) and high fat, HF (30%) diet. The main aim was to determine if the anti-obesity effect of MLCT was contributed solely by its triacylglycerol structure alone or its fatty acid composition or both. Out of the three types of MLCT, mice fed with Low Fat, LF (7%) E-MLCT had significantly (P<0.05) lower body weight gain (by ~30%), body fat accumulation (by ~37%) and hormone leptin level as compared to both the LF B-PKOPO and LF C-MLCT. Histological examination further revealed that dietary intake of E-MLCT inhibited hepatic lipid accumulation. Besides, analysis of serum profile also demonstrated that consumption of E-MLCT was better in regulating blood glucose compared to B-PKOPO and C-MLCT. Nevertheless, both B-PKO-PO and E-MLCT which contained higher level of myristic acid was found to be hypercholesterolemic compared to C-MLCT. In summary, our finding showed that triacylglycerol structure, fatty acid composition and fat dosage play a pivotal role in regulating visceral fat accumulation. Consumption of E-MLCT in low fat diet led to a significantly lesser body fat accumulation. It was postulated that the MLM/MLL/LMM/MML/LLM types of triacylglycerol and C8-C12 medium chain fatty acids were the main factors that contributed to the visceral fat suppressing effect of MLCT. Despite being able to reduce body fat, the so called healthful functional oil E-MLCT when taken in high amount do resulted in fat accumulation. In summary, E-MLCT when taken in moderation can be used to manage obesity issue. However, consumption of E-MLCT may lead to higher total cholesterol and LDL level.
  10. Fong MY, Wong KT, Rohela M, Tan LH, Adeeba K, Lee YY, et al.
    Trop Biomed, 2010 Dec;27(3):447-50.
    PMID: 21399585 MyJurnal
    We report a case of unusual cutaneous toxoplasmosis manifestation in a HIV-positive patient. He presented with hard and painful nodular lesions on the arms, hands and chest. Serology tests for anti-Toxoplasma antibody were negative. However, histopathologic examination of the lesion revealed foci of macrophages containing crescent-shaped organisms resembling the zoites of the protozoan parasite Toxoplasma gondii. Ultrastructure examination under electron microscopy and PCR confirmed the organism as T. gondii.
  11. Makharia G, Gibson PR, Bai JC, Karakan T, Lee YY, Collins L, et al.
    J Clin Gastroenterol, 2022 Jan 01;56(1):1-15.
    PMID: 34860201 DOI: 10.1097/MCG.0000000000001588
  12. Khine WWT, Zhang Y, Goie GJY, Wong MS, Liong M, Lee YY, et al.
    Sci Rep, 2019 05 24;9(1):7831.
    PMID: 31127186 DOI: 10.1038/s41598-019-44369-y
    Recent studies have realized the link between gut microbiota and human health and diseases. The question of diet, environment or gene is the determining factor for dominant microbiota and microbiota profile has not been fully resolved, for these comparative studies have been performed on populations of different ethnicities and in short-term intervention studies. Here, the Southern Chinese populations are compared, specifically the children of Guangzhou City (China), Penang City (west coast Malaysia) and Kelantan City (east coast Malaysia). These Chinese people have similar ancestry thus it would allow us to delineate the effect of diet and ethnicity on gut microbiota composition. For comparison, the Penang and Kelantan Malay children were also included. The results revealed that differences in microbiota genera within an ethnicity in different cities was due to differences in food type. Sharing the similar diet but different ethnicity in a city or different cities and living environment showed similar gut microbiota. The major gut microbiota (more than 1% total Operational Taxonomy Units, OTUs) of the children population are largely determined by diet but not ethnicity, environment, and lifestyle. Elucidating the link between diet and microbiota would facilitate the development of strategies to improve human health at a younger age.
  13. Lee YY
    PMID: 25705618 DOI: 10.3389/fmed.2014.00005
    Constipation and fecal incontinence (FI) are common complaints predominantly affecting the elderly and women. They are associated with significant morbidity and high healthcare costs. The causes are often multi-factorial and overlapping. With the advent of new technologies, we have a better understanding of their underlying pathophysiology which may involve disruption at any levels along the gut-brain-microbiota axis. Initial approach to management should always be the exclusion of secondary causes. Mild symptoms can be approached with conservative measures that may include dietary modifications, exercise, and medications. New prokinetics (e.g., prucalopride) and secretagogues (e.g., lubiprostone and linaclotide) are effective and safe in constipation. Biofeedback is the treatment of choice for dyssynergic defecation. Refractory constipation may respond to neuromodulation therapy with colectomy as the last resort especially for slow-transit constipation of neuropathic origin. Likewise, in refractory FI, less invasive approach can be tried first before progressing to more invasive surgical approach. Injectable bulking agents, sacral nerve stimulation, and SECCA procedure have modest efficacy but safe and less invasive. Surgery has equivocal efficacy but there are promising new techniques including dynamic graciloplasty, artificial bowel sphincter, and magnetic anal sphincter. Despite being challenging, there are no short of alternatives in our toolbox for the management of constipation and FI.
  14. Hassan SA, Rahman RA, Huda N, Wan Bebakar WM, Lee YY
    J R Coll Physicians Edinb, 2013;43(2):103-7.
    PMID: 23734349 DOI: 10.4997/JRCPE.2013.203
    Clostridum difficile (C. difficile) infection is increasingly seen among hospitalised patients with type 2 diabetes mellitus but its rate and associated risk factors are not known. We aimed to determine the rate and characteristics of hospital-acquired C. difficile infection in subjects with type 2 diabetes mellitus admitted into acute medical wards.
  15. Muthupalaniappen L, Norhayati M, Lee YY
    Korean J Parasitol, 2012 Mar;50(1):79-82.
    PMID: 22451739 DOI: 10.3347/kjp.2012.50.1.79
    Cat flea bite in humans results in extremely pruritic skin lesions. It has been reported to occur among those living in domiciliary accommodation. However, nosocomial infestation with cat flea has not been reported. We hereby report a case of nosocomial infestation of cat flea in a hospital facility. Identification of the parasite, its appropriate eradication, and adequate medical management of the patients resulted in a satisfactory outcome.
  16. Dhaliwal JS, Shahnaz M, Azrena A, Irda YA, Salawati M, Too CL, et al.
    Tissue Antigens, 2010 Feb;75(2):166-9.
    PMID: 20196825 DOI: 10.1111/j.1399-0039.2009.01410.x
    One hundred and fifty-eight Kadazan, Iban and Bidayuh individuals registered with the Malaysian Marrow Donor Registry were typed for human leukocyte antigen (HLA)-A, HLA-B and HLA-DR. Six, seven and eight HLA-A alleles as well as 13, 15 and 16 HLA-B alleles were detected in the Kadazan, Bidayuh and Iban, respectively. The most common HLA-A allele in all three groups was HLA-A*24 with a frequency of 0.456, 0.490 and 0.422 in the Kadazan, Bidayuh and Iban, respectively. The most common HLA-B allele detected in the Kadazan was HLA-B*40 with a frequency of 0.333; for the Bidayuh and the Iban it was HLA-B*15 with a frequency of 0.460 and 0.275, respectively. The HLA-DR allele with the highest frequency in the Kadazan was HLA-DR*1502 with a frequency of 0.500. In the Iban and the Bidayuh, HLA-DRB1*1202 was the most common DR allele with frequencies of 0.235 and 0.310, respectively. The two most common haplotypes for the Kadazan are A*34-B*38-DR*1502 and A*24-B*40-DR*0405, whereas for the Bidayuh they are A*24-B*15-DR*1602 and A*24-B*35-DR*1202 and for the Iban they are A*34-*B15-DR*1502 and A*24-B*15-DR*1202.
  17. Ma ZF, Majid NA, Yamaoka Y, Lee YY
    Front Microbiol, 2016;7:368.
    PMID: 27047479 DOI: 10.3389/fmicb.2016.00368
    Based on the hygiene hypothesis, a low prevalence of Helicobacter pylori (H. pylori) infection may explain the recent high prevalence of allergic diseases including food allergy. However, there are very few studies that investigate the relationship between H. pylori and food allergy.
  18. Jamaludin S, Mustaffa N, Che Hamzah NA, Syed Abdul Aziz SH, Lee YY
    BMC Gastroenterol, 2015;15:101.
    PMID: 26264957 DOI: 10.1186/s12876-015-0332-0
    Unchanged substrate in a negative rapid urease test may be reused to detect Helicobacter pylori (H. pylori). This could potentially reduce costs and wastage in low prevalence and resource-poor settings. We thus aimed to investigate the diagnostic accuracy of reused Pronto Dry and CLOtest kits, comparing this to the use of new Pronto Dry test kits and histopathological evaluation of gastric mucosal biopsies.
  19. Johari MI, Yusoff K, Haron J, Nadarajan C, Ibrahim KN, Wong MS, et al.
    Sci Rep, 2020 Jun 25;10(1):10599.
    PMID: 32587371 DOI: 10.1038/s41598-020-67806-9
    An amendment to this paper has been published and can be accessed via a link at the top of the paper.
  20. Mustaffa N, Lee SY, Mohd Nawi SN, Che Rahim MJ, Chee YC, Muhd Besari A, et al.
    J Glob Health, 2020 Dec;10(2):020370.
    PMID: 33214887 DOI: 10.7189/jogh.10.020370
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