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Rohman A, Irnawati, Windarsih A, Riswanto FDO, Indrayanto G, Fadzillah NA, Riyanto S, Bakar NKA. Application of Chromatographic and Spectroscopic-Based Methods for Analysis of Omega-3 (ω-3 FAs) and Omega-6 (ω-6 FAs) Fatty Acids in Marine Natural Products. Molecules 2023; 28:5524. [PMID: 37513396 PMCID: PMC10383577 DOI: 10.3390/molecules28145524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Omega-3 fatty acids v(ω-3 FAs) such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) and omega-6 fatty acids (ω-6 FAs) such as linoleic acid and arachidonic acid are important fatty acids responsible for positive effects on human health. The main sources of ω-3 FAs and ω-6 FAs are marine-based products, especially fish oils. Some food, supplements, and pharmaceutical products would include fish oils as a source of ω-3 FAs and ω-6 FAs; therefore, the quality assurance of these products is highly required. Some analytical methods mainly based on spectroscopic and chromatographic techniques have been reported. Molecular spectroscopy such as Infrared and Raman parallel to chemometrics has been successfully applied for quantitative analysis of individual and total ω-3 FAs and ω-6 FAs. This spectroscopic technique is typically applied as the alternative method to official methods applying chromatographic methods. Due to the capability to provide the separation of ω-3 FAs and ω-6 FAs from other components in the products, gas and liquid chromatography along with sophisticated detectors such as mass spectrometers are ideal analytical methods offering sensitive and specific results that are suitable for routine quality control.
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Affiliation(s)
- Abdul Rohman
- Halal Center, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
| | - Irnawati
- Faculty of Pharmacy, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
- Study Program of Pharmacy, Faculty of Pharmacy, Halu Oleo University, Kendari 93232, Indonesia
| | - Anjar Windarsih
- Research Center for Food Technology and Processing (PRTPP), National Research and Innovation Agency (BRIN), Yogyakarta 55861, Indonesia
- Department of Chemistry, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | | | | | - Nurrulhidayah A Fadzillah
- International Institute for Halal Research and Training, International Islamic University Malaysia, Kuala Lumpur 53100, Malaysia
| | - Sugeng Riyanto
- Study Program of Pharmacy, Faculty of Health Sciences and Pharmacy, Universitas Gunadarma, Jakarta 16451, Indonesia
| | - Nor Kartini Abu Bakar
- Department of Chemistry, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia
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Ahmmed F, Gordon KC, Killeen DP, Fraser-Miller SJ. Detection and Quantification of Adulteration in Krill Oil with Raman and Infrared Spectroscopic Methods. Molecules 2023; 28:molecules28093695. [PMID: 37175105 PMCID: PMC10180486 DOI: 10.3390/molecules28093695] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/14/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023] Open
Abstract
Raman and infrared spectroscopy, used as individual and low-level fused datasets, were evaluated to identify and quantify the presence of adulterants (palm oil, PO; ω-3 concentrates in ethyl ester, O3C and fish oil, FO) in krill oil. These datasets were qualitatively analysed with principal component analysis (PCA) and classified as adulterated or unadulterated using support vector machines (SVM). Using partial least squares regression (PLSR), it was possible to identify and quantify the adulterant present in the KO mixture. Raman spectroscopy performed better (r2 = 0.98; RMSEP = 2.3%) than IR spectroscopy (r2 = 0.91; RMSEP = 4.2%) for quantification of O3C in KO. A data fusion approach further improved the analysis with model performance for quantification of PO (r2 = 0.98; RMSEP = 2.7%) and FO (r2 = 0.76; RMSEP = 9.1%). This study demonstrates the potential use of Raman and IR spectroscopy to quantify adulterants present in KO.
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Affiliation(s)
- Fatema Ahmmed
- Te Whai Ao-Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Chemistry, University of Otago, P.O. Box 56, Dunedin 9016, New Zealand
| | - Keith C Gordon
- Te Whai Ao-Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Chemistry, University of Otago, P.O. Box 56, Dunedin 9016, New Zealand
| | - Daniel P Killeen
- The New Zealand Institute for Plant and Food Research Limited, P.O. Box 5114, Port Nelson, Nelson 7043, New Zealand
| | - Sara J Fraser-Miller
- Te Whai Ao-Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Chemistry, University of Otago, P.O. Box 56, Dunedin 9016, New Zealand
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Lintvedt TA, Andersen PV, Afseth NK, Heia K, Lindberg SK, Wold JP. Raman spectroscopy and NIR hyperspectral imaging for in-line estimation of fatty acid features in salmon fillets. Talanta 2023; 254:124113. [PMID: 36473242 DOI: 10.1016/j.talanta.2022.124113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 12/03/2022]
Abstract
Raman spectroscopy was compared with near infrared (NIR) hyperspectral imaging for determination of fat composition (%EPA + DHA) in salmon fillets at short exposure times. Fillets were measured in movement for both methods. Salmon were acquired from several different farming locations in Norway with different feeding regimes, representing a realistic variation of salmon in the market. For Raman, we investigated three manual scanning strategies; i) line scan of loin, ii) line scan of belly and iii) sinusoidal scan of belly at exposure times of 2s and 4s. NIR images were acquired while the fillets moved on a conveyor belt at 40 cm/s, which corresponds to an acquisition time of 1s for a 40 cm long fillet. For NIR images, three different regions of interest (ROI) were investigated including the i) whole fillet, ii) belly segment, and iii) loin segment. For both Raman and NIR measurements, we investigated an untrimmed and trimmed version of the fillets, both relevant for industrial in-line evaluation. For the trimmed fillets, a fat rich deposition layer in the belly was removed. The %EPA + DHA models were validated by cross validation (N = 51) and using an independent test set (N = 20) which was acquired in a different season. Both Raman and NIR showed promising results and high performances in the cross validation, with R2CV = 0.96 for Raman at 2s exposure and R2CV = 0.97 for NIR. High performances were obtained also for the test set, but while Raman had low and stable biases for the test set, the biases were high and varied for the NIR measurements. Analysis of variance on the squared test set residuals showed that performance for Raman measurements were significantly higher than NIR at 1% significance level (p = 0.000013) when slope-and-bias errors were not corrected, but not significant when residuals were slope-and-bias corrected (p = 0.28). This indicated that NIR was more sensitive to matrix effects. For Raman, signal-to-noise ratio was the main limitation and there were indications that Raman was close to a critical sample exposure time at the 2s signal accumulation.
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Affiliation(s)
- Tiril Aurora Lintvedt
- Norwegian Institute for Food, Fisheries and Aquaculture Research, Muninbakken 9-13, Breivika, Tromsø, 9291, Norway; Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, 1432, Norway.
| | - Petter Vejle Andersen
- Norwegian Institute for Food, Fisheries and Aquaculture Research, Muninbakken 9-13, Breivika, Tromsø, 9291, Norway
| | - Nils Kristian Afseth
- Norwegian Institute for Food, Fisheries and Aquaculture Research, Muninbakken 9-13, Breivika, Tromsø, 9291, Norway
| | - Karsten Heia
- Norwegian Institute for Food, Fisheries and Aquaculture Research, Muninbakken 9-13, Breivika, Tromsø, 9291, Norway
| | - Stein-Kato Lindberg
- Norwegian Institute for Food, Fisheries and Aquaculture Research, Muninbakken 9-13, Breivika, Tromsø, 9291, Norway
| | - Jens Petter Wold
- Norwegian Institute for Food, Fisheries and Aquaculture Research, Muninbakken 9-13, Breivika, Tromsø, 9291, Norway
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Quantitative analysis of fatty acids and vitamin E and total lipid profiling of dietary supplements from the German market. Eur Food Res Technol 2023. [DOI: 10.1007/s00217-022-04193-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
AbstractCertain polyunsaturated fatty acids with n-3 double bonds are essential nutrients for the human body and are part of the bilayer of cell membranes or precursors of tissue hormones. The most abundant dietary n-3 fatty acids in human nutrition are α-linolenic, eicosapentaenoic, and docosahexaenoic acid and can be taken up through dietary sources such as vegetable oils or fish or, alternatively, dietary supplements with high levels of n-3 fatty acids. In previous studies, considerable variation of lipid patterns and quantities of n-3 fatty acids were observed. In this study, 33 dietary supplements from the German market, based on fish-, krill-, microalgae, and plant oil, have been analyzed. Lipid profiling (LC–MS) revealed triacylglycerols as the dominant lipid species in most samples. However, krill oil was rich in phospholipids and samples containing fatty acid concentrates featured abundant fatty acid ethyl esters and diacylglycerols. Furthermore, total lipid profiles showed considerable variance depending on the lipid sources (e.g., fish or plant oil), which was also apparent in fatty acid analysis. The contents of n-3 fatty acids ranged between 150 and 570 mg/g capsule content (GC–MS) and vitamin E (α-tocopherol and tocopheryl acetate) were found in quantities ranging from 1.2 to 86.1 mg/g capsule content (HPLC–UV/Vis). While our analyses indicated a good agreement between labeled and present quantities of total n-3 fatty acids and vitamin E for the majority of samples, significant differences in agreement between individual fatty acids were observed, as well as frequent mismatches between declared and present vitamin E derivatives.
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Rapid detection of pork oil adulteration in snakehead fish oil using FTIR-ATR spectroscopy and chemometrics for halal authentication. CHEMICAL PAPERS 2023. [DOI: 10.1007/s11696-023-02671-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Ahmmed F, Killeen DP, Gordon KC, Fraser-Miller SJ. Rapid Quantitation of Adulterants in Premium Marine Oils by Raman and IR Spectroscopy: A Data Fusion Approach. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27144534. [PMID: 35889406 PMCID: PMC9319805 DOI: 10.3390/molecules27144534] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/12/2022] [Accepted: 07/12/2022] [Indexed: 11/30/2022]
Abstract
This study uses Raman and IR spectroscopic methods for the detection of adulterants in marine oils. These techniques are used individually and as low-level fused spectroscopic data sets. We used cod liver oil (CLO) and salmon oil (SO) as the valuable marine oils mixed with common adulterants, such as palm oil (PO), omega-3 concentrates in ethyl ester form (O3C), and generic fish oil (FO). We showed that support vector machines (SVM) can classify the adulterant present in both CLO and SO samples. Furthermore, partial least squares regression (PLSR) may be used to quantify the adulterants present. For example, PO and O3C adulterated samples could be detected with a RMSEP value less than 4%. However, the FO adulterant was more difficult to quantify because of its compositional similarity to CLO and SO. In general, data fusion improved the RMSEP for PO and O3C detection. This shows that Raman and IR spectroscopy can be used in concert to provide a useful analytical test for common adulterants in CLO and SO.
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Affiliation(s)
- Fatema Ahmmed
- Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Chemistry, University of Otago, Dunedin 9016, New Zealand; (F.A.); (K.C.G.)
| | - Daniel P. Killeen
- Seafood Technologies, The New Zealand Institute for Plant and Food Research Limited, Nelson 7010, New Zealand;
| | - Keith C. Gordon
- Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Chemistry, University of Otago, Dunedin 9016, New Zealand; (F.A.); (K.C.G.)
| | - Sara J. Fraser-Miller
- Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Chemistry, University of Otago, Dunedin 9016, New Zealand; (F.A.); (K.C.G.)
- Correspondence:
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Lintvedt TA, Andersen PV, Afseth NK, Marquardt B, Gidskehaug L, Wold JP. Feasibility of In-Line Raman Spectroscopy for Quality Assessment in Food Industry: How Fast Can We Go? APPLIED SPECTROSCOPY 2022; 76:559-568. [PMID: 35216528 PMCID: PMC9082979 DOI: 10.1177/00037028211056931] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Raman spectroscopy is a viable tool within process analytical technologies due to recent technological advances. In this article, we evaluate the feasibility of Raman spectroscopy for in-line applications in the food industry by estimating the concentration of the fatty acids EPA + DHA in ground salmon samples (n = 63) and residual bone concentration in samples of mechanically recovered ground chicken (n = 66). The samples were measured under industry like conditions: They moved on a conveyor belt through a dark cabinet where they were scanned with a wide area illumination standoff Raman probe. Such a setup should be able to handle relevant industrial conveyor belt speeds, and it was studied how different speeds (i.e., exposure times) influenced the signal-to-noise ratio (SNR) of the Raman spectra as well as the corresponding model performance. For all samples we applied speeds that resulted in 1 s, 2 s, 4 s, and 10 s exposure times. Samples were scanned in both heterogenous and homogenous state. The slowest speed (10 s exposure) yielded prediction errors (RMSECV) of 0.41%EPA + DHA and 0.59% ash for the salmon and chicken data sets, respectively. The more in-line relevant exposure time of 1 s resulted in increased RMSECV values, 0.84% EPA + DHA and 0.84% ash, respectively. The increase in prediction error correlated closely with the decrease in SNR. Further improvements of model performance were possible through different noise reduction strategies. Model performance for homogenous and heterogenous samples was similar, suggesting that the presented Raman scanning approach has the potential to work well also on intact heterogenous foods. The estimation errors obtained at these high speeds are likely acceptable for industrial use, but successful strategies to increase SNR will be key for widespread in-line use in the food industry.
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Affiliation(s)
- Tiril Aurora Lintvedt
- Nofima AS, Troms∅, Norway
- Tiril Aurora Lintvedt, Faculty of Science and Technology, NMBU, Nofima—Norwegian Institute for Food, Fisheries, and Aquaculture Research, Muninbakken 9-13, Breivika, Tromsø 9291, Norway.
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Didrihsone E, Dubencovs K, Grube M, Shvirksts K, Suleiko A, Suleiko A, Vanags J. Crypthecodinium cohnii Growth and Omega Fatty Acid Production in Mediums Supplemented with Extract from Recycled Biomass. Mar Drugs 2022; 20:68. [PMID: 35049923 PMCID: PMC8779103 DOI: 10.3390/md20010068] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 01/05/2022] [Accepted: 01/07/2022] [Indexed: 02/04/2023] Open
Abstract
Crypthecodinium cohnii is a marine heterotrophic dinoflagellate that can accumulate high amounts of omega-3 polyunsaturated fatty acids (PUFAs), and thus has the potential to replace conventional PUFAs production with eco-friendlier technology. So far, C. cohnii cultivation has been mainly carried out with the use of yeast extract (YE) as a nitrogen source. In the present study, alternative carbon and nitrogen sources were studied: the extraction ethanol (EE), remaining after lipid extraction, as a carbon source, and dinoflagellate extract (DE) from recycled algae biomass C. cohnii as a source of carbon, nitrogen, and vitamins. In mediums with glucose and DE, the highest specific biomass growth rate reached a maximum of 1.012 h-1, while the biomass yield from substrate reached 0.601 g·g-1. EE as the carbon source, in comparison to pure ethanol, showed good results in terms of stimulating the biomass growth rate (an 18.5% increase in specific biomass growth rate was observed). DE supplement to the EE-based mediums promoted both the biomass growth (the specific growth rate reached 0.701 h-1) and yield from the substrate (0.234 g·g-1). The FTIR spectroscopy data showed that mediums supplemented with EE or DE promoted the accumulation of PUFAs/docosahexaenoic acid (DHA), when compared to mediums containing glucose and commercial YE.
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Affiliation(s)
- Elina Didrihsone
- Latvian State Institute of Wood Chemistry, LV1006 Riga, Latvia; (K.D.); (A.S.); (A.S.); (J.V.)
| | - Konstantins Dubencovs
- Latvian State Institute of Wood Chemistry, LV1006 Riga, Latvia; (K.D.); (A.S.); (A.S.); (J.V.)
- A/S Biotehniskais Centrs, LV1006 Riga, Latvia
- Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, LV1048 Riga, Latvia
| | - Mara Grube
- Institute of Microbiology and Biotechnology, University of Latvia, LV1004 Riga, Latvia; (M.G.); (K.S.)
| | - Karlis Shvirksts
- Institute of Microbiology and Biotechnology, University of Latvia, LV1004 Riga, Latvia; (M.G.); (K.S.)
| | - Anastasija Suleiko
- Latvian State Institute of Wood Chemistry, LV1006 Riga, Latvia; (K.D.); (A.S.); (A.S.); (J.V.)
| | - Arturs Suleiko
- Latvian State Institute of Wood Chemistry, LV1006 Riga, Latvia; (K.D.); (A.S.); (A.S.); (J.V.)
- A/S Biotehniskais Centrs, LV1006 Riga, Latvia
| | - Juris Vanags
- Latvian State Institute of Wood Chemistry, LV1006 Riga, Latvia; (K.D.); (A.S.); (A.S.); (J.V.)
- A/S Biotehniskais Centrs, LV1006 Riga, Latvia
- Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, LV1048 Riga, Latvia
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Wang K, Li Z, Li J, Lin H. Raman spectroscopic techniques for nondestructive analysis of agri-foods: A state-of-the-art review. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.10.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Blay C, Haffray P, D'Ambrosio J, Prado E, Dechamp N, Nazabal V, Bugeon J, Enez F, Causeur D, Eklouh-Molinier C, Petit V, Phocas F, Corraze G, Dupont-Nivet M. Genetic architecture and genomic selection of fatty acid composition predicted by Raman spectroscopy in rainbow trout. BMC Genomics 2021; 22:788. [PMID: 34732127 PMCID: PMC8564959 DOI: 10.1186/s12864-021-08062-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 09/29/2021] [Indexed: 01/22/2023] Open
Abstract
Background In response to major challenges regarding the supply and sustainability of marine ingredients in aquafeeds, the aquaculture industry has made a large-scale shift toward plant-based substitutions for fish oil and fish meal. But, this also led to lower levels of healthful n−3 long-chain polyunsaturated fatty acids (PUFAs)—especially eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids—in flesh. One potential solution is to select fish with better abilities to retain or synthesise PUFAs, to increase the efficiency of aquaculture and promote the production of healthier fish products. To this end, we aimed i) to estimate the genetic variability in fatty acid (FA) composition in visceral fat quantified by Raman spectroscopy, with respect to both individual FAs and groups under a feeding regime with limited n-3 PUFAs; ii) to study the genetic and phenotypic correlations between FAs and processing yields- and fat-related traits; iii) to detect QTLs associated with FA composition and identify candidate genes; and iv) to assess the efficiency of genomic selection compared to pedigree-based BLUP selection. Results Proportions of the various FAs in fish were indirectly estimated using Raman scattering spectroscopy. Fish were genotyped using the 57 K SNP Axiom™ Trout Genotyping Array. Following quality control, the final analysis contained 29,652 SNPs from 1382 fish. Heritability estimates for traits ranged from 0.03 ± 0.03 (n-3 PUFAs) to 0.24 ± 0.05 (n-6 PUFAs), confirming the potential for genomic selection. n-3 PUFAs are positively correlated to a decrease in fat deposition in the fillet and in the viscera but negatively correlated to body weight. This highlights the potential interest to combine selection on FA and against fat deposition to improve nutritional merit of aquaculture products. Several QTLs were identified for FA composition, containing multiple candidate genes with indirect links to FA metabolism. In particular, one region on Omy1 was associated with n-6 PUFAs, monounsaturated FAs, linoleic acid, and EPA, while a region on Omy7 had effects on n-6 PUFAs, EPA, and linoleic acid. When we compared the effectiveness of breeding programmes based on genomic selection (using a reference population of 1000 individuals related to selection candidates) or on pedigree-based selection, we found that the former yielded increases in selection accuracy of 12 to 120% depending on the FA trait. Conclusion This study reveals the polygenic genetic architecture for FA composition in rainbow trout and confirms that genomic selection has potential to improve EPA and DHA proportions in aquaculture species. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08062-7.
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Affiliation(s)
- Carole Blay
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France
| | | | - Jonathan D'Ambrosio
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France.,SYSAAF, Station LPGP-INRAE, Rennes, France
| | - Enora Prado
- University of Rennes, CNRS, ISCR - UMR 6226, ScanMAT - UMS 2001, Rennes, France
| | - Nicolas Dechamp
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France
| | - Virginie Nazabal
- University of Rennes, CNRS, ISCR - UMR 6226, ScanMAT - UMS 2001, Rennes, France
| | | | | | - David Causeur
- Laboratoire de Mathématiques Appliquées, IRMAR, Agrocampus Ouest, Rennes, France
| | | | | | - Florence Phocas
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France
| | - Geneviève Corraze
- INRAE, University of Pau & Pays Adour, E2S UPPA, UMR1419 NuMéA, St Pée sur, Nivelle, France
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Amorim TL, Granato ÁS, de Oliveira Mendes T, de Oliveira MAL, Amarante GW, de la Fuente MA, Gómez-Cortés P. Lipid classification of fish oil omega-3 supplements by 1H NMR and multivariate analysis. J Food Compost Anal 2021. [DOI: 10.1016/j.jfca.2021.104060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Meng W, Jiang Y, Rothschild D, Lipke M, Hall G, Wang L. Modeling the structure and infrared spectra of omega-3 fatty acid esters. J Chem Phys 2021; 153:035101. [PMID: 32716186 DOI: 10.1063/5.0015402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Omega-3 dietary supplements provide a rich source of the active moieties eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which exist in the form of triacylglycerols or ethyl esters. Infrared (IR) spectroscopy provides a rapid and quantitative tool to assess the quality of these products as specific normal modes, in particular the ester carbonyl stretch modes, exhibit characteristic spectral features for the two ester forms of omega-3 fatty acids. To uncover the origin of the observed spectra, in this work, we perform molecular dynamics simulations of EPA and DHA ethyl esters and triacylglycerols to characterize their conformation, packing, and dynamics in the liquid phase and use a mixed quantum/classical approach to calculate their IR absorption spectra in the ester carbonyl stretch region. We show that the ester liquids exhibit slow dynamics in spectral diffusion and translational and rotational motion, consistent with the diffusion ordered NMR spectroscopy measurements. We further demonstrate that the predicted IR spectra are in good agreement with experiments and reveal how a competition between intermolecular and intramolecular interactions gives rise to distinct absorption peaks for the fatty acid esters.
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Affiliation(s)
- Wenting Meng
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Yaoyukun Jiang
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Daniel Rothschild
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Mark Lipke
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Gene Hall
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Lu Wang
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey 08854, USA
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Wang Y, Liu Y, Ma L, Li H, Wang Z, Xu J, Xue C. The oxidation mechanism of phospholipids in Antarctic krill oil promoted by metal ions. Food Chem 2020; 333:127448. [DOI: 10.1016/j.foodchem.2020.127448] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 06/02/2020] [Accepted: 06/27/2020] [Indexed: 01/06/2023]
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Kurtovic I, Nalder TD, Cleaver H, Marshall SN. Immobilisation of Candida rugosa lipase on a highly hydrophobic support: A stable immobilised lipase suitable for non-aqueous synthesis. ACTA ACUST UNITED AC 2020; 28:e00535. [PMID: 33088731 PMCID: PMC7566202 DOI: 10.1016/j.btre.2020.e00535] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 09/26/2020] [Accepted: 09/28/2020] [Indexed: 12/21/2022]
Abstract
Lipase from Candida rugosa (CrL) was immobilised on highly hydrophobic, octadecyl methacrylate resin (Lifetech™ ECR8806M) via interfacial adsorption. The aim was to produce a stable biocatalyst suitable for use in a range of lipid-modifying reactions. Immobilisation was carried out in 10 mM phosphate buffer (pH 6.0) over 24 h at 21 °C. High protein binding of 58.7 ± 4.9 mg/g dry support accounted for ∼53 % of the applied protein. The activity recovery against tributyrin was 74.0 ± 1.1 %. The specific activity of immobilised CrL against tributyrin was considerably higher than that of Novozym® 435, at 1.79 ± 0.05 and 1.08 ± 0.04 U/mg bound protein, respectively. Incubation with high concentrations (10 % w/v) of both Triton X-100 and SDS resulted in only a small reduction in immobilised lipase activity. Solvent-free synthesis of glycerides by the FFA-saturated immobilised CrL was successful over 6 reaction cycles, with no apparent loss of activity.
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Affiliation(s)
- Ivan Kurtovic
- Nelson Research Centre, The New Zealand Institute for Plant and Food Research Limited, 293-297 Akersten Street, Nelson, 7010, New Zealand
| | - Tim D Nalder
- Nelson Research Centre, The New Zealand Institute for Plant and Food Research Limited, 293-297 Akersten Street, Nelson, 7010, New Zealand.,School of Life and Environmental Sciences, Deakin University, 75 Pigdons Road, Waurn Ponds, 3216, Victoria, Australia
| | - Helen Cleaver
- Nelson Research Centre, The New Zealand Institute for Plant and Food Research Limited, 293-297 Akersten Street, Nelson, 7010, New Zealand
| | - Susan N Marshall
- Nelson Research Centre, The New Zealand Institute for Plant and Food Research Limited, 293-297 Akersten Street, Nelson, 7010, New Zealand
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15
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Hespanhol MC, Souza JC, Pasquini C. Feasibility of a portable, low-cost near-infrared spectrophotometer for the quality screening of omega-3 dietary supplements. J Pharm Biomed Anal 2020; 189:113436. [PMID: 32599486 DOI: 10.1016/j.jpba.2020.113436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/16/2020] [Accepted: 06/17/2020] [Indexed: 01/08/2023]
Abstract
The quality of omega-3 supplements, commercialized at substantial high prices and supplied by several manufacturers, must be assessed. The existing reference methods to attest the quality of omega-3 supplements are based on chromatography, which requires expensive equipment, a cumbersome analytical protocol to determine the contents of the active components, and operates ex-situ. This work evaluates, comprehensively, the feasibility of a low-cost near-infrared spectrophotometer and simple chemometrics to achieve fast and robust characterization of omega-3 supplements. The necessary attention, very often neglected, to the performance of the low-cost portable equipment is highlighted, and an appropriate sample measurement protocol is established. A non-conventional way to construct multivariate regression models based on partial least square regression to evaluated the omega-3 content in the supplements was proposed using few references values and completing the data set with the label values selected using the X-Y relation outliers plots. The results showed that the simple, fast and inexpensive approach proposed could deliver in situ relevant information related to the quality of the supplements such as identification several raw materials employed in its fabrication, screening for the content of the active components, identify frauds/non-conformities, and report on unscrupulous marketing practices.
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Affiliation(s)
- Maria C Hespanhol
- Group of Analysis and Education for Sustainability (GAES), Chemistry Department, Federal University of Viçosa (UFV), Viçosa, MG, 36570-900, Brazil.
| | - Jamille Carvalho Souza
- Group of Analysis and Education for Sustainability (GAES), Chemistry Department, Federal University of Viçosa (UFV), Viçosa, MG, 36570-900, Brazil
| | - Celio Pasquini
- Chemistry Institute, State University of Campinas - UNICAMP, Rua Monteiro Lobato, 290, Campinas, SP, 13083-862, Brazil
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16
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Foley S, Miller E, Braziel S, Lee S. Molecular organization in mixed SOPC and SDPC model membranes: Water permeability studies of polyunsaturated lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183365. [DOI: 10.1016/j.bbamem.2020.183365] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 12/16/2022]
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17
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Karunathilaka SR, Yakes BJ, Choi SH, Brückner L, Mossoba MM. Comparison of the Performance of Partial Least Squares and Support Vector Regressions for Predicting Fatty Acids and Fatty Acid Classes in Marine Oil Dietary Supplements by Using Vibrational Spectroscopic Data. J Food Prot 2020; 83:881-889. [PMID: 32028530 DOI: 10.4315/jfp-19-563] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 01/21/2020] [Indexed: 11/11/2022]
Abstract
ABSTRACT Simple, fast, and accurate analytical techniques for verifying the accuracy of label declarations for marine oil dietary supplements containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are required because of the increased consumption of these products. We recently developed broad-based partial least squares regression (PLS-R) models to quantify six fatty acids (FAs) and FA classes by using the spectroscopic data from a portable Fourier transform infrared (FTIR) device and a benchtop Fourier transform near infrared (FT-NIR) spectrometer. We developed an improved quantification method for these FAs and FA classes by incorporating a nonlinear calibration approach based on the machine learning technique support vector machines. For the two spectroscopic methods, high accuracy in prediction was indicated by low root mean square error of prediction and by correlation coefficients (R2) close to 1, indicating excellent model performance. The percent accuracy of the support vector regression (SV-R) model predicted values for EPA and DHA in the reference material was 90 to 110%. In comparison to PLS-R, SV-R accuracy for prediction of FA and FA class concentrations was up to 2.4 times higher for both ATR-FTIR and FT-NIR spectroscopic data. The SV-R models also provided closer agreement with the certified and reference values for the prediction of EPA and DHA in the reference standard. Based on our findings, the SV-R methods had superior accuracy and predictive quality for predicting the FA concentrations in marine oil dietary supplements. The combination of SV-R with ATR-FTIR and/or FT-NIR spectroscopic data can potentially be applied for the rapid screening of marine oil products to verify the accuracy of label declarations. HIGHLIGHTS
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Affiliation(s)
- Sanjeewa R Karunathilaka
- Joint Institute for Food Safety and Applied Nutrition, University of Maryland, 2134 Patapsco Building, College Park, Maryland 20742
| | - Betsy Jean Yakes
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Sung Hwan Choi
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Lea Brückner
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, 5001 Campus Drive, College Park, Maryland 20740, USA
| | - Magdi M Mossoba
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, 5001 Campus Drive, College Park, Maryland 20740, USA
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18
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Killeen DP, Card A, Gordon KC, Perry NB. First Use of Handheld Raman Spectroscopy to Analyze Omega-3 Fatty Acids in Intact Fish Oil Capsules. APPLIED SPECTROSCOPY 2020; 74:365-371. [PMID: 31746217 DOI: 10.1177/0003702819877415] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are commercially important omega-3 fatty acids found in fish oils. Here we demonstrate that a handheld Raman spectrometer can be used to quantitate these compounds in intact fish oil capsules, avoiding oxidizing risk. Partial least squares regression models were prepared by relating Raman spectral variance to EPA and DHA concentrations determined using gas chromatography-mass spectrometry (GC-MS) analysis of fatty acid methyl esters in 15 commercial samples containing 145-473 mg g-1 EPA and 101-260 mg·g-1 DHA. Handheld Fourier transform (FT)-Raman models had root mean square errors of cross-validation of 38 mg g-1, 24 mg g-1, and 32 mg·g-1 for EPA, DHA, and EPA+DHA, respectively. Models generated from a benchtop FT-Raman spectrometer had corresponding errors of 32 mg·g-1, 22 mg·g-1, and 26 mg·g-1. By comparison, average standard deviations from triplicate GC-MS analyses were 11 mg·g-1 for EPA and 9 mg·g-1 for DHA.
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Affiliation(s)
| | - Asli Card
- The New Zealand Institute for Plant and Food Research Limited, Nelson, New Zealand
| | | | - Nigel Brian Perry
- Department of Chemistry, University of Otago, Dunedin, New Zealand
- The New Zealand Institute for Plant and Food Research Limited, Department of Chemistry, University of Otago, Dunedin, New Zealand
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19
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Quantification and monitoring the heat-induced formation of trans fatty acids in edible oils by Raman Spectroscopy. JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2019. [DOI: 10.1007/s11694-019-00140-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Karunathilaka SR, Choi SH, Mossoba MM, Yakes BJ, Brückner L, Ellsworth Z, Srigley CT. Rapid classification and quantification of marine oil omega-3 supplements using ATR-FTIR, FT-NIR and chemometrics. J Food Compost Anal 2019. [DOI: 10.1016/j.jfca.2018.12.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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21
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Heller M, Gemming L, Tung C, Grant R. Oxidation of fish oil supplements in Australia. Int J Food Sci Nutr 2019; 70:540-550. [DOI: 10.1080/09637486.2018.1542666] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Monique Heller
- Australasian Research Institute, Sydney Adventist Hospital, Wahroonga, Australia
- University of Sydney, Nutrition and Dietetics Group, Charles Perkins Centre, School of Life and Environmental Sciences, Sydney, Australia
| | - Luke Gemming
- University of Sydney, Nutrition and Dietetics Group, Charles Perkins Centre, School of Life and Environmental Sciences, Sydney, Australia
| | - Chin Tung
- Australasian Research Institute, Sydney Adventist Hospital, Wahroonga, Australia
| | - Ross Grant
- Australasian Research Institute, Sydney Adventist Hospital, Wahroonga, Australia
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
- Sydney Adventist Hospital Clinical School, University of Sydney, Sydney, Australia
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22
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Broadhurst CL, Schmidt WF, Qin J, Chao K, Kim MS. Continuous Gradient Temperature Raman Spectroscopy of Fish Oils Provides Detailed Vibrational Analysis and Rapid, Nondestructive Graphical Product Authentication. Molecules 2018; 23:molecules23123293. [PMID: 30545062 PMCID: PMC6320940 DOI: 10.3390/molecules23123293] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/04/2018] [Accepted: 12/05/2018] [Indexed: 01/02/2023] Open
Abstract
Background: Gradient temperature Raman spectroscopy (GTRS) applies the continuous temperature gradients utilized in differential scanning calorimetry (DSC) to Raman spectroscopy, providing a new means for rapid high throughput material identification and quality control. Methods: Using 20 Mb three-dimensional data arrays with 0.2 °C increments and first/second derivatives allows complete assignment of solid, liquid and transition state vibrational modes. The entire set or any subset of the any of the contour plots, first derivatives or second derivatives can be utilized to create a graphical standard to quickly authenticate a given source. In addition, a temperature range can be specified that maximizes information content. Results: We compared GTRS and DSC data for five commercial fish oils that are excellent sources of docosahexaenoic acid (DHA; 22:6n-3) and eicosapentaenoic acid (EPA; 20:5n-3). Each product has a unique, distinctive response to the thermal gradient, which graphically and spectroscopically differentiates them. We also present detailed Raman data and full vibrational mode assignments for EPA and DHA. Conclusion: Complex lipids with a variety of fatty acids and isomers have three dimensional structures based mainly on how structurally similar sites pack. Any localized non-uniformity in packing results in discrete “fingerprint” molecular sites due to increased elasticity and decreased torsion.
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Affiliation(s)
- C Leigh Broadhurst
- Sensors Development Laboratory, Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, USA.
- Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, USA.
| | - Walter F Schmidt
- Sensors Development Laboratory, Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, USA.
| | - Jianwei Qin
- Sensors Development Laboratory, Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, USA.
| | - Kuanglin Chao
- Sensors Development Laboratory, Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, USA.
| | - Moon S Kim
- Sensors Development Laboratory, Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, USA.
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23
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Sprague M, Cooper S, Tocher DR, Betancor MB. Encapsulated Fish Oil Products Available in the UK Meet Regulatory Guidelines With Respect to EPA + DHA Contents and Oxidative Status. EUR J LIPID SCI TECH 2018. [DOI: 10.1002/ejlt.201800105] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Matthew Sprague
- Faculty of Natural Sciences; Institute of Aquaculture; University of Stirling; Stirling FK9 4LA Scotland UK
| | - Sean Cooper
- Faculty of Natural Sciences; Institute of Aquaculture; University of Stirling; Stirling FK9 4LA Scotland UK
| | - Douglas R. Tocher
- Faculty of Natural Sciences; Institute of Aquaculture; University of Stirling; Stirling FK9 4LA Scotland UK
| | - Mónica B. Betancor
- Faculty of Natural Sciences; Institute of Aquaculture; University of Stirling; Stirling FK9 4LA Scotland UK
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24
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Bettjeman BI, Hofman KA, Burgess EJ, Perry NB, Killeen DP. Seafood Phospholipids: Extraction Efficiency and Phosphorous Nuclear Magnetic Resonance Spectroscopy (31
P NMR) Profiles. J AM OIL CHEM SOC 2018. [DOI: 10.1002/aocs.12086] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Bodhi I. Bettjeman
- Seafood Processing and Marine Products; The New Zealand Institute for Plant & Food Research Limited, 300 Wakefield Quay; Nelson 7010 New Zealand
| | - Kathleen A. Hofman
- Seafood Processing and Marine Products; The New Zealand Institute for Plant & Food Research Limited, 300 Wakefield Quay; Nelson 7010 New Zealand
| | - Elaine J. Burgess
- Biological Chemistry and Bioactives, The New Zealand Institute for Plant & Food Research Limited, Department of Chemistry; University of Otago, P.O. Box 56; Dunedin 9054 New Zealand
| | - Nigel B. Perry
- Biological Chemistry and Bioactives, The New Zealand Institute for Plant & Food Research Limited, Department of Chemistry; University of Otago, P.O. Box 56; Dunedin 9054 New Zealand
- Department of Chemistry; University of Otago, P.O. Box 56; Dunedin 9054 New Zealand
| | - Daniel P. Killeen
- Seafood Processing and Marine Products; The New Zealand Institute for Plant & Food Research Limited, 300 Wakefield Quay; Nelson 7010 New Zealand
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25
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Broadhurst CL, Schmidt WF, Nguyen JK, Qin J, Chao K, Kim MS. Gradient Temperature Raman Spectroscopy of Fatty Acids with One to Six Double Bonds Identifies Specific Carbons and Provides Systematic Three Dimensional Structures. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/jbpc.2018.91001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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26
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Broadhurst CL, Schmidt WF, Nguyen JK, Qin J, Chao K, Kim MS. Continuous gradient temperature Raman spectroscopy from -100 to 40°C yields new molecular models of arachidonic acid and 2-Arachidonoyl-1-stearoyl-sn-glycero-3-phosphocholine. Prostaglandins Leukot Essent Fatty Acids 2017; 127:6-15. [PMID: 29156157 DOI: 10.1016/j.plefa.2017.09.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 08/29/2017] [Accepted: 09/27/2017] [Indexed: 01/31/2023]
Abstract
Despite its biochemical importance, a complete Raman analysis of arachidonic acid (AA, 20:4n-6) has never been reported. Gradient temperature Raman spectroscopy (GTRS) applies the temperature gradients utilized in differential scanning calorimetry (DSC) to Raman spectroscopy, providing a straightforward technique to identify molecular rearrangements that occur near and at phase transitions. Herein we utilize the GTRS technique for AA and 1-18:0, 2-20:4n-6 phosphatidyl choline (AAPC) from cryogenic to mammalian body temperatures. 20Mb three-dimensional data arrays with 0.2°C increments and first/second derivatives allowed complete assignment of solid, liquid and transition state vibrational modes. The AA DSC shows a large exothermic peak at -60°C indicating crystallization or a similar major structural change. No exothermic peak of this magnitude was observed in six other unsaturated lipids (DHA, n-3DPA, n-6DPA, LA, ALA, OA). Melting in AA occurs over a large range: (-60 to -35°C): very large frequency offsets and intensity changes correlate with premelting initiating circa -60°C, followed by melting (-37°C). Novel, unique 3D structures for both molecules reveal that AA is not symmetric as a free fatty acid, and it changes significantly when in the sn-2 phospholipid position. Further, different CH and CH2 sites are unequally elastic and nonequivalent.
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Affiliation(s)
- C Leigh Broadhurst
- Environmental Microbiology and Food Safety Laboratory, US Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, United States; Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, United States.
| | - Walter F Schmidt
- Environmental Microbiology and Food Safety Laboratory, US Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, United States
| | - Julie K Nguyen
- Environmental Microbiology and Food Safety Laboratory, US Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, United States
| | - Jianwei Qin
- Environmental Microbiology and Food Safety Laboratory, US Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, United States
| | - Kuanglin Chao
- Environmental Microbiology and Food Safety Laboratory, US Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, United States
| | - Moon S Kim
- Environmental Microbiology and Food Safety Laboratory, US Department of Agriculture Agricultural Research Service, 10300 Baltimore Avenue, Beltsville, MD 20705, United States
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27
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Response to a Comment by Albert et al. (Nutrients 2017, 9, 137) Entitled "Concerns with the Study on Australian and New Zealand Fish Oil Products" by Nichols et al. (Nutrients 2016, 8, 703). Nutrients 2017; 9:nu9060583. [PMID: 28590416 PMCID: PMC5490562 DOI: 10.3390/nu9060583] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 06/05/2017] [Accepted: 06/06/2017] [Indexed: 11/17/2022] Open
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