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  1. Impact of prolonged storage on quality assessment properties and constituents of honey: A systematic review
    Manickavasagam G, Saaid M, Lim V
    J Food Sci, 2024 Feb;89(2):811-833.
    PMID: 38224177 DOI: 10.1111/1750-3841.16921
    This systematic review paper aims to discuss the trend in quality assessment properties and constituents of honey at different storage conditions and confer the possible whys and wherefores associated with the significant changes. Initially, a literature search was conducted through Google Scholar, ScienceDirect, PubMed, and Scopus databases. In total, 43 manuscripts published between 2001 and 2023 that met the inclusion and exclusion criteria were chosen for the review. As an outcome of this review, prolonged honey storage could deteriorate sensory, nutritional, and antioxidant properties and promote fermentation, granulation, microbial growth, carcinogenicity, organotoxicity, and nephrotoxicity. This systematic review also recognized that diastase activity, invertase activity, 5-hydroxymethylfurfural content, proline content, sugar content, amino acids, and vitamins could be used as indicators to distinguish fresh and stored honey based on the significant test (p-value) in the reported studies. However, all the reported studies used the simplest approach (one-way ANOVA) to identify the significant differences in the analyzed parameter during the storage period and none of them reported an approach to identify the most influential parameter at different storage conditions. In conclusion, orthogonal partial least squares discriminant analysis (supervised multivariate statistical tool) has to be employed in future studies to find the most influential parameter and could be used to potent chemical markers to distinguish fresh and stored honey because this analysis is incorporated with S-plot, variable importance of projection, and one-way ANOVA, which can produce the most accurate and precise results rather solely depending on one-way ANOVA.
    Matched MeSH terms: Amino Acids/analysis
  2. Nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry metabolomics studies on non-organic soybeans versus organic soybeans (Glycine max), and their fermentation by Rhizopus oligosporus
    Chong SG, Ismail IS, Ahmad Azam A, Tan SJ, Shaari K, Tan JK
    J Sci Food Agric, 2023 Apr;103(6):3146-3156.
    PMID: 36426592 DOI: 10.1002/jsfa.12355
    BACKGROUND: Soybeans (Glycine max) are high in proteins and isoflavones, which offer many health benefits. It has been suggested that the fermentation process enhances the nutrients in the soybeans. Organic foods are perceived as better than non-organic foods in terms of health benefits, yet little is known about the difference in the phytochemical content that distinguishes the quality of organic soybeans from non-organic soybeans. This study investigated the chemical profiles of non-organic (G, T, U, UB) and organic (C, COF, A, R, B, Z) soybeans (G. max [L.] Merr.) and their metabolite changes after fermentation with Rhizopus oligosporus.

    RESULTS: A clear separation was only observed between non-organic G and organic Z, which were then selected for further investigation in the fermentation of soybeans (GF and ZF). All four groups (G, Z, GF, ZF) were analyzed using nuclear magnetic resonance (NMR) spectroscopy along with liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this way a total of 41 and 47 metabolites were identified respectively, with 12 in common. A clear variation (|log1.5 FC| > 2 and P amino acids and organic acids were found in ZF. An additional four metabolites clustered as C-glycosylflavonoids were discovered from MS/MS-based molecular networking.

    CONCLUSION: Chemical profiles of non-organic and organic soybeans exhibited no significant difference. However, the metabolite profile of the unfermented soybeans, which were higher in sugars, shifted to higher amino acid and organic acid content after fermentation, thereby potentially enhancing their nutritional value. © 2022 Society of Chemical Industry.

    Matched MeSH terms: Amino Acids/analysis
  3. Fulltext 1H-NMR-Based Metabolomics: An Integrated Approach for the Detection of the Adulteration in Chicken, Chevon, Beef and Donkey Meat
    Akhtar MT, Samar M, Shami AA, Mumtaz MW, Mukhtar H, Tahir A, et al.
    Molecules, 2021 Jul 30;26(15).
    PMID: 34361796 DOI: 10.3390/molecules26154643
    Meat is a rich source of energy that provides high-value animal protein, fats, vitamins, minerals and trace amounts of carbohydrates. Globally, different types of meats are consumed to fulfill nutritional requirements. However, the increasing burden on the livestock industry has triggered the mixing of high-price meat species with low-quality/-price meat. This work aimed to differentiate different meat samples on the basis of metabolites. The metabolic difference between various meat samples was investigated through Nuclear Magnetic Resonance spectroscopy coupled with multivariate data analysis approaches like principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA). In total, 37 metabolites were identified in the gluteal muscle tissues of cow, goat, donkey and chicken using 1H-NMR spectroscopy. PCA was found unable to completely differentiate between meat types, whereas OPLS-DA showed an apparent separation and successfully differentiated samples from all four types of meat. Lactate, creatine, choline, acetate, leucine, isoleucine, valine, formate, carnitine, glutamate, 3-hydroxybutyrate and α-mannose were found as the major discriminating metabolites between white (chicken) and red meat (chevon, beef and donkey). However, inosine, lactate, uracil, carnosine, format, pyruvate, carnitine, creatine and acetate were found responsible for differentiating chevon, beef and donkey meat. The relative quantification of differentiating metabolites was performed using one-way ANOVA and Tukey test. Our results showed that NMR-based metabolomics is a powerful tool for the identification of novel signatures (potential biomarkers) to characterize meats from different sources and could potentially be used for quality control purposes in order to differentiate different meat types.
    Matched MeSH terms: Amino Acids/analysis
  4. Fulltext Evolutionary and genomic analysis of four SARS-CoV-2 isolates circulating in March 2020 in Sri Lanka; Additional evidence on multiple introduction and further transmission
    Satharasinghe DA, Parakatawella PMSDK, Premarathne JMKJK, Jayasooriya LJPAP, Prathapasinghe GA, Yeap SK
    Epidemiol Infect, 2021 03 16;149:e78.
    PMID: 33722321 DOI: 10.1017/S0950268821000583
    The molecular epidemiology of the virus and mapping helps understand the epidemics' evolution and apply quick control measures. This study provides genomic evidence of multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) introductions into Sri Lanka and virus evolution during circulation. Whole-genome sequences of four SARS-CoV-2 strains obtained from coronavirus disease 2019 (COVID-19) positive patients reported in Sri Lanka during March 2020 were compared with sequences from Europe, Asia, Africa, Australia and North America. The phylogenetic analysis revealed that the sequence of the sample of the first local patient collected on 10 March, who contacted tourists from Italy, was clustered with SARS-CoV-2 strains collected from Italy, Germany, France and Mexico. Subsequently, the sequence of the isolate obtained on 19 March also clustered in the same group with the samples collected in March and April from Belgium, France, India and South Africa. The other two strains of SARS-CoV-2 were segregated from the main cluster, and the sample collected from 16 March clustered with England and the sample collected on 30 March showed the highest genetic divergence to the isolate of Wuhan, China. Here we report the first molecular epidemiological study conducted on circulating SARS-CoV-2 in Sri Lanka. The finding provides the robustness of molecular epidemiological tools and their application in tracing possible exposure in disease transmission during the pandemic.
    Matched MeSH terms: Amino Acids/analysis
  5. Microbial dynamics, metabolomic profiles, and the correlation between them during fermentation of serofluid dish
    Wei J, Ren W, Wang L, Liu M, Tian X, Ding G, et al.
    J Sci Food Agric, 2020 Dec;100(15):5627-5636.
    PMID: 32712996 DOI: 10.1002/jsfa.10690
    BACKGROUND: Serofluid dish, a traditional Chinese fermented food, possesses unique flavors and health beneficial effects. These properties are likely due to the sophisticated metabolic networks during fermentation, which are mainly driven by microbiota. However, the exact roles of metabolic pathways and the microbial community during this process remain equivocal.

    RESULTS: Here, we investigated the microbial dynamics by next-generation sequencing, and outlined a differential non-targeted metabolite profiling in the process of serofluid dish fermentation using the method of hydrophilic interaction liquid chromatography column with ultra-high-performance liquid chromatography-quadruple time-of-flight mass spectrometry. Lactobacillus was the leading genus of bacteria, while Pichia and Issatchenkia were the dominant fungi. They all accumulated during fermentation. In total, 218 differential metabolites were identified, of which organic acids, amino acids, sugar and sugar alcohols, fatty acids, and esters comprised the majority. The constructed metabolic network showed that tricarboxylic acid cycle, urea cycle, sugar metabolism, amino acids metabolism, choline metabolism, and flavonoid metabolism were regulated by the fermentation. Furthermore, correlation analysis revealed that the leading fungi, Pichia and Issatchenkia, were linked to organic acids, amino acid and sugar metabolism, flavonoids, and several other flavor and functional components. Antibacterial tests indicated the antibacterial effect of serofluid soup against Salmonella and Staphylococcus.

    CONCLUSION: This work provides new insights into the complex microbial and metabolic networks during serofluid dish fermentation, and a theoretical basis for the optimization of its industrial production. © 2020 Society of Chemical Industry.

    Matched MeSH terms: Amino Acids/analysis
  6. Low-temperature and long-time heating regimes on non-volatile compound and taste traits of beef assessed by the electronic tongue system
    Ismail I, Hwang YH, Joo ST
    Food Chem, 2020 Aug 01;320:126656.
    PMID: 32224424 DOI: 10.1016/j.foodchem.2020.126656
    The influence of temperature-time combinations on non-volatile compound and taste traits of beef semitendinosus muscles tested by the electronic tongue was studied. Single-stage sous-vide at 60 and 70 °C (6 and 12 h), and two-stage sous-vide that sequentially cooked at 45 °C (3 h) and 60 °C (either 3 or 9 h) were compared with traditional cooking at 70 °C (30 min). Umami was better explained in the given model of partial least squares regression than astringency, sourness, saltiness, bitterness, and richness. Sous-vide at 70 °C for 12 h characterized the most umami, likely adenosine-5'-monophosphate (AMP) and guanosine-5'-monophosphate (GMP) as significant contributors. Two-stage sous-vide projected higher histidine, leucine, inosine, and hypoxanthine with the astringent and sour taste significant after 6 and 12 h cooking, respectively. Equivalent umami concentration (EUC) between umami amino acids and umami nucleotides showed a strong relationship to umami taste assessed by the electronic tongue.
    Matched MeSH terms: Amino Acids/analysis
  7. Characterization of Polar and Non-Polar Compounds of House Edible Bird's Nest (EBN) from Johor, Malaysia
    Hun Lee T, Hau Lee C, Alia Azmi N, Kavita S, Wong S, Znati M, et al.
    Chem Biodivers, 2020 Jan;17(1):e1900419.
    PMID: 31721431 DOI: 10.1002/cbdv.201900419
    This work investigated the polar (PC: protein, amino acid and metabolite) and non-polar (NPC: fatty acid) compounds and bioactivity characteristics of the EBN harvested from the state of Johor in Malaysia. The electrophoretic gels exhibited 15 protein bands (16-173 kD) with unique protein profile. Amino acids analysis by AccQ⋅Tag method revealed 18 types of amino acids in EBN. Metabolite profiling was performed using High-Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometer (HPLC-QTOF/MS) technique and a total of 54 compounds belonging to different groups were detected and identified. These findings help to uncover the relation of therapeutic activity of EBN. The EBN was further extracted with AcOEt and BuOH. The AcOEt extract was fractionated into three fractions (F1 -F3 ), and the high triglyceride content in F2 was verified by gC-FID. The three groups of fatty acids discovered in EBN are 48.43 % of poly-unsaturated (PUFA), 25.35 % of saturated fatty acids (SFA) and 24.74 % of mono-unsaturated fat (MUFA). This is the first time to report results ofEBN, BuOH, and AcOEt extracts and of fraction F2 (TEBN) on their analysis for their antioxidant activities by DPPH, ABTS and catalase assay and for their paraoxonase and anti-tyrosinase activities. The results showed that TEBN exhibited the significant bioactivity in all assays. These findings suggest that TEBN is a good source for natural bioactive compounds in promoting body vigor. Current work widened the content of EBN especially on the triglyceride and also marked the content of specific location (Johor, Malaysia) of EBN origin.
    Matched MeSH terms: Amino Acids/analysis*
  8. Fulltext A Comparative Characterization of Physicochemical and Antioxidants Properties of Processed Heterotrigona itama Honey from Different Origins and Classification by Chemometrics Analysis
    Shamsudin S, Selamat J, Sanny M, A R SB, Jambari NN, Khatib A
    Molecules, 2019 Oct 29;24(21).
    PMID: 31671885 DOI: 10.3390/molecules24213898
    Stingless bee honey produced by Heterotrigona itama from different botanical origins was characterised and discriminated. Three types of stingless bee honey collected from acacia, gelam, and starfruit nectars were analyzed and compared with Apis mellifera honey. The results showed that stingless bee honey samples from the three different botanical origins were significantly different in terms of their moisture content, pH, free acidity, total soluble solids, colour characteristics, sugar content, amino acid content and antioxidant properties. Stingless bee honey was significantly different from Apis mellifera honey in terms of physicochemical and antioxidant properties. The amino acid content was further used in the chemometrics analysis to evaluate the role of amino acid in discriminating honey according to botanical origin. Partial least squares-discriminant analysis (PLS-DA) revealed that the stingless bee honey was completely distinguishable from Apis mellifera honey. Notably, a clear distinction between the stingless bee honey types was also observed. The specific amino acids involved in the distinction of honey were cysteine for acacia and gelam, phenylalanine and 3-hydroxyproline for starfruit, and proline for Apis mellifera honey. The results showed that all honey samples were successfully classified based on amino acid content.
    Matched MeSH terms: Amino Acids/analysis
  9. Identification of the amino acids in the Major Histocompatibility Complex class II region of Scottish Blackface sheep that are associated with resistance to nematode infection
    Stear A, Ali AOA, Brujeni GN, Buitkamp J, Donskow-Łysoniewska K, Fairlie-Clarke K, et al.
    Int J Parasitol, 2019 09;49(10):797-804.
    PMID: 31306661 DOI: 10.1016/j.ijpara.2019.05.003
    Lambs with the Major Histocompatibility Complex DRB1*1101 allele have been shown to produce fewer nematode eggs following natural and deliberate infection. These sheep also possess fewer adult Teladorsagia circumcincta than sheep with alternative alleles at the DRB1 locus. However, it is unclear if this allele is responsible for the reduced egg counts or merely acts as a marker for a linked gene. This study defined the MHC haplotypes in a population of naturally infected Scottish Blackface sheep by PCR amplification and sequencing, and examined the associations between MHC haplotypes and faecal egg counts by generalised linear mixed modelling. The DRB1*1101 allele occurred predominately on one haplotype and a comparison of haplotypes indicated that the causal mutation or mutations occurred in or around this locus. Additional comparisons with another resistant haplotype indicated that mutations in or around the DQB2*GU191460 allele were also responsible for resistance to nematode infections. Further analyses identified six amino acid substitutions in the antigen binding site of DRB1*1101 that were significantly associated with reductions in the numbers of adult T. circumcincta.
    Matched MeSH terms: Amino Acids/analysis*
  10. Nutritional evaluation on Lignosus cameronensis C. S. Tan, a medicinal Polyporaceae
    Fung SY, Cheong PCH, Tan NH, Ng ST, Tan CS
    IUBMB Life, 2019 07;71(7):821-826.
    PMID: 30629799 DOI: 10.1002/iub.2006
    Sclerotial powder of a cultivated species of the Tiger Milk Mushroom, Lignosus cameronensis was analysed for its nutritional components and compared against species of the same genus, Lignosus rhinocerus and Lignosus tigris. All three species have been used by indigenous tribes in Peninsular Malaysia as medicinal mushrooms. Content of carbohydrate, fibre, mineral, amino acid, palatable index, fat, ash and moisture were determined. L. cameronensis sclerotial material consists of carbohydrate (79.7%), protein (12.4%) and dietary fibre (5.4%) with low fat (1.7%) and no free sugar. It has the highest content of total carbohydrate (791 g kg-1 ), energy value (3,700 kcal kg-1 ) and calcium (0.85 g kg-1 ). The crude protein content (123 g kg-1 ) is comparable to that of L. rhinocerus with its main amino acids consisting of glutamic acid, aspartic acid and leucine. The umami index is determined to be 0.27. The total essential amino acid (45 g kg-1 ) is comparable to that of L. tigris. The main mineral is potassium (1.51 g kg-1 ) and the Na/K ratio was <0.6. Heavy metals such as mercury, cadmium, lead and arsenic were absent. L. cameronensis has the highest amount of food energy, total carbohydrate and calcium compared to those of both L. rhinocerus and L. tigris. The essential amino acids comprised almost 40% of the total amino acid content, slightly more than that reported from sclerotial powder of the L. tigris. © 2019 IUBMB Life, 9999(9999):1-6, 2019.
    Matched MeSH terms: Amino Acids/analysis*
  11. Improved collagen extraction from jellyfish (Acromitus hardenbergi) with increased physical-induced solubilization processes
    Khong NMH, Yusoff FM, Jamilah B, Basri M, Maznah I, Chan KW, et al.
    Food Chem, 2018 Jun 15;251:41-50.
    PMID: 29426422 DOI: 10.1016/j.foodchem.2017.12.083
    Efficiency and effectiveness of collagen extraction process contribute to huge impacts to the quality, supply and cost of the collagen produced. Jellyfish is a potential sustainable source of collagen where their applications are not limited by religious constraints and threats of transmittable diseases. The present study compared the extraction yield, physico-chemical properties and toxicology in vitro of collagens obtained by the conventional acid-assisted and pepsin-assisted extraction to an improved physical-aided extraction process. By increasing physical intervention, the production yield increased significantly compared to the conventional extraction processes (p amino acids composition to those extracted using pepsin (p > .05) while retaining high molecular weight distributions and polypeptide profiles similar to those extracted using only acid. Moreover, they exhibited better appearance, instrumental colour and were found to be non-toxic in vitro and free of heavy metal contamination.
    Matched MeSH terms: Amino Acids/analysis
  12. Chemical composition and physicochemical properties of tropical red seaweed, Gracilaria changii
    Chan PT, Matanjun P
    Food Chem, 2017 Apr 15;221:302-310.
    PMID: 27979207 DOI: 10.1016/j.foodchem.2016.10.066
    A study on the proximate composition, minerals, vitamins, carotenoids, amino acids, fatty acids profiles and some physicochemical properties of freeze dried Gracilaria changii was conducted. It was discovered that this seaweed was high in dietary fibre (64.74±0.82%), low in fat (0.30±0.02%) and Na/K ratio (0.12±0.02). The total amino acid content was 91.90±7.70% mainly essential amino acids (55.87±2.15mgg(-1)) which were comparable to FAO/WHO requirements. The fatty acid profiles were dominated by the polyunsaturated fatty acids particularly docosahexaenoic (48.36±6.76%) which led to low ω6/ω3, atherogenic, and thrombogenic index. The physicochemical properties of this seaweed namely the water holding and the swelling capacity were comparable to some commercial fibre rich products. This study suggested that G. changii could be potentially used as ingredients to improve nutritive value and texture of functional foods for human consumption.
    Matched MeSH terms: Amino Acids/analysis*
  13. Comparison of physicochemical and functional properties of duck feet and bovine gelatins
    Kuan YH, Nafchi AM, Huda N, Ariffin F, Karim AA
    J Sci Food Agric, 2017 Mar;97(5):1663-1671.
    PMID: 27465360 DOI: 10.1002/jsfa.7970
    BACKGROUND: Previous studies have indicated that duck feet are a rich source of gelatin extractable from avian sources. In this study, the physicochemical and functional properties of avian gelatin extracted from duck feet (DFG) with acetic acid were compared with those of commercial bovine gelatin (BG).

    RESULTS: The yield of DFG obtained in this study was 7.01 ± 0.31%. High-performance liquid chromatography analysis indicated that the imino acid content was slightly lower for DFG compared with BG (P < 0.05). Differences in molecular size and amino acids between DFG and BG were also observed. The isoelectric points of DFG and BG were at pH 8 and 5 respectively, and the overall protein solubility of BG was higher than that of DFG. Gels prepared from BG exhibited higher bloom strength, viscosity and clarity and were darker in colour compared with DFG gels (P < 0.05). The gelling and melting points of BG were 21.8 and 29.47 °C respectively, while those of DFG were 20.5 and 27.8 °C respectively. BG exhibited slightly better emulsifying and foaming properties compared with DFG.

    CONCLUSION: Although some differences between DFG and BG were observed, the disparities were small, which indicates that DFG could be exploited commercially as an alternative source of gelatin. © 2016 Society of Chemical Industry.

    Matched MeSH terms: Amino Acids/analysis
  14. Alterations in juvenile diploid and triploid African catfish skin gelatin yield and amino acid composition: Effects of chlorpyrifos and butachlor exposures
    Karami A, Karbalaei S, Zad Bagher F, Ismail A, Simpson SL, Courtenay SC
    Environ Pollut, 2016 Aug;215:170-177.
    PMID: 27182978 DOI: 10.1016/j.envpol.2016.05.014
    Skin is a major by-product of the fisheries and aquaculture industries and is a valuable source of gelatin. This study examined the effect of triploidization on gelatin yield and proximate composition of the skin of African catfish (Clarias gariepinus). We further investigated the effects of two commonly used pesticides, chlorpyrifos (CPF) and butachlor (BUC), on the skin gelatin yield and amino acid composition in juvenile full-sibling diploid and triploid African catfish. In two separate experiments, diploid and triploid C. gariepinus were exposed for 21 days to graded CPF [mean measured: 10, 16, or 31 μg/L] or BUC concentrations [Mean measured: 22, 44, or 60 μg/L]. No differences in skin gelatin yield, amino acid or proximate compositions were observed between diploid and triploid control groups. None of the pesticide treatments affected the measured parameters in diploid fish. In triploids, however, gelatin yield was affected by CPF treatments while amino acid composition remained unchanged. Butachlor treatments did not alter any of the measured variables in triploid fish. To our knowledge, this study is the first to investigate changes in the skin gelatin yield and amino acid composition in any animal as a response to polyploidization and/or contaminant exposure.
    Matched MeSH terms: Amino Acids/analysis
  15. Nutritional composition, antioxidant properties, and toxicology evaluation of the sclerotium of Tiger Milk Mushroom Lignosus tigris cultivar E
    Kong BH, Tan NH, Fung SY, Pailoor J, Tan CS, Ng ST
    Nutr Res, 2016 Feb;36(2):174-83.
    PMID: 26598045 DOI: 10.1016/j.nutres.2015.10.004
    The Tiger Milk Mushroom (Lignosus spp.) is an important medicinal mushroom in Southeast Asia and has been consumed frequently by the natives as a cure for a variety of illnesses. In this study, we hypothesized that Lignosus tigris (cultivar E) sclerotium may contain high nutritional value and antioxidant properties, is nontoxic and a potential candidate as a dietary supplement. The chemical and amino acid compositions of the sclerotium were evaluated and antioxidant activities of the sclerotial extracts were assessed using ferric reducing antioxidant power; 1,1-diphenyl-2-picrylhydrazyl; and superoxide anion radical scavenging assays. Acute toxicity of the L. tigris E sclerotium was assessed using a rat model study. The sclerotium was found to be rich in carbohydrate, protein, and dietary fibers with small amounts of fat, calories, and sugar. The amino acid composition of the protein contains all essential amino acids, with a protein score of 47. The sclerotial extracts contain phenolics, terpenoids, and glucan. The ferric reducing antioxidant power values of the various sclerotial extracts (hot water, cold water, and methanol) ranged from 0.008 to 0.015 mmol min(-1) g(-1) extract, while the 1,1-diphenyl-2-picrylhydrazyl and superoxide anion radical scavenging activities ranged from 0.11 to 0.13, and -2.81 to 9.613 mmol Trolox equivalents g(-1) extract, respectively. Acute toxicity assessment indicated that L. tigris E sclerotial powder was not toxic at the dose of 2000 mg kg(-1). In conclusion, L. tigris E sclerotium has the potential to be developed into a functional food and nutraceutical.
    Matched MeSH terms: Amino Acids/analysis
  16. Formation and reduction of 5-hydroxymethylfurfural at frying temperature in model system as a function of amino acid and sugar composition
    Kavousi P, Mirhosseini H, Ghazali H, Ariffin AA
    Food Chem, 2015 Sep 1;182:164-70.
    PMID: 25842323 DOI: 10.1016/j.foodchem.2015.02.135
    5-Hydroxymethylfurfural (HMF) is formed during heat treatment of carbohydrate-containing foods, especially in a deep-fat frying process. This study aimed to investigate the effect of amino acids on the formation and reduction of HMF from glucose, fructose and sucrose at frying temperature in model systems containing binary mixtures of an amino acid and a sugar in equal concentrations (0.3M). The results revealed that the formation of HMF from sugars accelerated in the presence of acidic amino acids (i.e. glutamic and aspartic acids). Conversely, the presence of basic amino acids (i.e. lysine, arginine and histidine) led to reduced concentrations of HMF to non-detectable levels in model systems. The results showed that both pH and heating time significantly affected the formation of HMF from fructose in the presence of glutamic acid. In this regard, a higher amount of HMF was formed at lower pH.
    Matched MeSH terms: Amino Acids/analysis*
  17. RP-HPLC method using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate incorporated with normalization technique in principal component analysis to differentiate the bovine, porcine and fish gelatins
    Azilawati MI, Hashim DM, Jamilah B, Amin I
    Food Chem, 2015 Apr 1;172:368-76.
    PMID: 25442566 DOI: 10.1016/j.foodchem.2014.09.093
    The amino acid compositions of bovine, porcine and fish gelatin were determined by amino acid analysis using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate as derivatization reagent. Sixteen amino acids were identified with similar spectral chromatograms. Data pre-treatment via centering and transformation of data by normalization were performed to provide data that are more suitable for analysis and easier to be interpreted. Principal component analysis (PCA) transformed the original data matrix into a number of principal components (PCs). Three principal components (PCs) described 96.5% of the total variance, and 2 PCs (91%) explained the highest variances. The PCA model demonstrated the relationships among amino acids in the correlation loadings plot to the group of gelatins in the scores plot. Fish gelatin was correlated to threonine, serine and methionine on the positive side of PC1; bovine gelatin was correlated to the non-polar side chains amino acids that were proline, hydroxyproline, leucine, isoleucine and valine on the negative side of PC1 and porcine gelatin was correlated to the polar side chains amino acids that were aspartate, glutamic acid, lysine and tyrosine on the negative side of PC2. Verification on the database using 12 samples from commercial products gelatin-based had confirmed the grouping patterns and the variables correlations. Therefore, this quantitative method is very useful as a screening method to determine gelatin from various sources.
    Matched MeSH terms: Amino Acids/analysis*
  18. Fulltext HLA-A SNPs and amino acid variants are associated with nasopharyngeal carcinoma in Malaysian Chinese
    Chin YM, Mushiroda T, Takahashi A, Kubo M, Krishnan G, Yap LF, et al.
    Int J Cancer, 2015 Feb 1;136(3):678-87.
    PMID: 24947555 DOI: 10.1002/ijc.29035
    Nasopharyngeal carcinoma (NPC) arises from the mucosal epithelium of the nasopharynx and is constantly associated with Epstein-Barr virus type 1 (EBV-1) infection. We carried out a genome-wide association study (GWAS) of 575,247 autosomal SNPs in 184 NPC patients and 236 healthy controls of Malaysian Chinese ethnicity. Potential association signals were replicated in a separate cohort of 260 NPC patients and 245 healthy controls. We confirmed the association of HLA-A to NPC with the strongest signal detected in rs3869062 (p = 1.73 × 10(-9)). HLA-A fine mapping revealed associations in the amino acid variants as well as its corresponding SNPs in the antigen peptide binding groove (p(HLA-A-aa-site-99) = 3.79 × 10(-8), p(rs1136697) = 3.79 × 10(-8)) and T-cell receptor binding site (p(HLA-A-aa-site-145) = 1.41 × 10(-4), p(rs1059520) = 1.41 × 10(-4)) of the HLA-A. We also detected strong association signals in the 5'-UTR region with predicted active promoter states (p(rs41545520) = 7.91 × 10(-8)). SNP rs41545520 is a potential binding site for repressor ATF3, with increased binding affinity for rs41545520-G correlated with reduced HLA-A expression. Multivariate logistic regression diminished the effects of HLA-A amino acid variants and SNPs, indicating a correlation with the effects of HLA-A*11:01, and to a lesser extent HLA-A*02:07. We report the strong genetic influence of HLA-A on NPC susceptibility in the Malaysian Chinese.
    Matched MeSH terms: Amino Acids/analysis
  19. Validation of a reverse-phase high-performance liquid chromatography method for the determination of amino acids in gelatins by application of 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate reagent
    Azilawati MI, Hashim DM, Jamilah B, Amin I
    J Chromatogr A, 2014 Aug 1;1353:49-56.
    PMID: 24797394 DOI: 10.1016/j.chroma.2014.04.050
    In-house method validation was conducted to determine amino acid composition in gelatin by a pre-column derivatization procedure with the 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate reagent. The analytical parameters revealed that the validated method was capable of selectively performing a good chromatographic separation for 18 amino acids in less than 40 min; the overall detection and quantitation limit for amino acids fell into ranges of 5.68-12.48 and 36.0-39.0 pmol/μl, respectively; the matrix effect was not observed, and the linearity range was 37.5-1000 pmol/μl. The accuracy (precision and recovery) analyses of the method were conducted under repeatable conditions on different days in random order. Method precision revealed by HorRat values was significantly less than 2, except for histidine with a precision of 2.19, and the method recoveries had a range of 80-115% except for alanine which was recovered at 79.4%. The findings were reproducible and accurately defined, and the method was found to be suited to routine analysis of amino acid composition in gelatin-based ingredients.
    Matched MeSH terms: Amino Acids/analysis*
  20. Fulltext Intrastrain comparison of the chemical composition and antioxidant activity of an edible mushroom, Pleurotus giganteus, and its potent neuritogenic properties
    Phan CW, David P, Tan YS, Naidu M, Wong KH, Kuppusamy UR, et al.
    ScientificWorldJournal, 2014;2014:378651.
    PMID: 25121118 DOI: 10.1155/2014/378651
    Two strains of Pleurotus giganteus (commercial and wild) were tested for their ability to induce neurite outgrowth in rat pheochromocytoma (PC12) and mouse neuroblastoma-2a (N2a) cells. Treatment with the mushroom extracts resulted in neuronal differentiation and neuronal elongation, but not nerve growth factor (NGF) production. Linoleic acid (4.5-5.0%, w/w) which is a major fatty acid present in the ethanol extract promoted NGF biosynthesis when augmented with low concentration of NGF (5 ng/mL). The two strains of mushroom were found to be high in protein (154-192 g kg(-1)), total polysaccharides, phenolics, and flavonoids as well as vitamins B1, B2, and B3. The total phenolics present in the mushroom extracts were positively correlated to the antioxidant activity (free radical scavenging, ferric reducing power, and lipid peroxidation inhibition). To conclude, P. giganteus could potentially be used in well-balanced diet and as a source of dietary antioxidant to promote neuronal health.
    Matched MeSH terms: Amino Acids/analysis
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