Authentication of Two Bio-Active Fish Oils by Qualitative Lipid Profiling Using Semi-Targeted Approach: An Exploratory Study.

BACKGROUND: Fish oils, which are rich in health-promoting polyunsaturated fatty acids (PUFA), have emerged as promising functional foods in the global health and wellness food market. Their source regarding the fish type, season, and location of harvesting might influence the nutritional value of such bioactive oils and determine their market price. The differences in price among such oils often lead to economically motivated mislabeling and adulteration. OBJECTIVE: In this study, our objective was to demonstrate how a qualitative targeted shotgun lipid profile workflow using an electrospray ionization-quadrupole-linear ion trap MS (QTrap) could differentiate fish oils originating from two different species. METHODS: Five samples each of sardine (Sardinella longiceps) oil and shark (Echinorhinus brucus) liver oil were diluted to a concentration of 80 µg/mL in chloroform-methanol (1 + 2, v/v) with 5 mM ammonium acetate. These samples were directly infused into a QTrap MS. The data were acquired for 23 precursor ion and 4 neutral loss scan experiments in the positive ionization mode and compared. RESULTS: We identified the following major lipid classes: cholesteryl ester, diacyl glycerol, triacylglycerol, monoalkyldiacylglycerol, and phophatydyl choline. The relative peak areas of the identified lipid species, when subjected to supervised multivariate analysis, could effectively distinguish the sardine oil and shark liver oil. CONCLUSIONS: The approach will be useful in establishing authenticity of fish oil and to support the regulatory agencies in dispute resolution. It can also be extended to establish authenticity in other agricultural and food commodities. HIGHLIGHTS: This paper reports a proof of concept for authenticating PUFA-rich fish supplements. A shotgun targeted lipidomics profile and chemometrics modeling successfully discriminated sardine oil and shark liver oil.

Simultaneous authentication of species identity and geographical origin of shrimps: Untargeted metabolomics to recurrent biomarker ions.

Mandatory disclosure of the species identity, production method, and geographical origin are embedded in the regulations and traceability systems, governing international seafood trade. A high-resolution mass spectrometry-based metabolomics approach could simultaneously authenticate the species identity and geographical origin of commercially important shrimps. The highly innovative approach spared the need for multiple testing methods which are in routine use currently. A robust chemometric model, developed using the metabolite fingerprint dataset, could accurately predict the species identity of the shrimp samples. Subsequently, species-specific biomarkers were discovered and a tandem mass spectrometry method for authentication of the species was developed. Two other chemometric models from the metabolomics experiment accurately predicted the geographical origin of king prawns and tiger prawns. The study has shown for the first time that food-metabolomics along with chemometrics can simultaneously check for multiple seafood fraud issues in the global seafood supply-chain.

Sardine oil loaded vanillic acid grafted chitosan microparticles, a new functional food ingredient: attenuates myocardial oxidative stress and apoptosis in cardiomyoblast cell lines (H9c2).

Fish oil has been widely recognized as an excellent dietary source of polyunsaturated n-3 fatty acids such as EPA and DHA. However, it can undergo oxidation easily resulting in the formation of toxic off flavor compounds such as hydroperoxides. These compounds adversely affect the nutritional quality and may induce several stress reactions in body. To solve this problem, a new antioxidant bio-material, vanillic acid-grafted chitosan (Va-g-Ch), was synthesized and used as a wall material for microencapsulation of fish oil. The sardine oil loaded Va-g-Ch microparticles could be a potential functional food ingredient considering the numerous health benefits of fish oil, chitosan, and vanillic acid. The current study aimed to investigate the possible protective effect of sardine oil-loaded Va-g-Ch microparticles against doxorubicin-induced cardiotoxicity and the underlying mechanisms. In vitro cytotoxicity evaluation was conducted using H9c2 cardiomyocytes. MTT assay revealed that effective cytoprotective effect was induced by a sample concentration of 12.5 µg/mL. Results of apoptosis by double fluorescent staining with acridine orange/ethidium bromide and caspase-3 evaluation by ELISA substantiated the above findings. Further, flow cytometric determination of membrane potential, relative expression of NF-κB by PCR, and ROS determination using DCFH-DA also confirmed the protective effect of encapsulated sardine oil against doxorubicin-induced cardiotoxicity. NF-κB expression was down-regulated nearly by 50% on cells treated with encapsulated sardine oil. Altogether, the results revealed that sardine oil-loaded Va-g-Ch microparticles demonstrated potential cell protection against doxorubicin-induced oxidative stress.

Microencapsulation of sardine oil: Application of vanillic acid grafted chitosan as a bio-functional wall material.

Vanillic acid grafted chitosan (Va-g-Ch) was evaluated as a new antioxidant wall material for microencapsulation of polyunsaturated fatty acid rich sardine oil. A high grafting ratio of 305mg vanillic acid equivalent/g of polymer was achieved using a free radical mediated grafting reaction. Oil in water emulsion was prepared with an optimised combination of Va-g-Ch and Tween 20 (3.2:1). Sardine oil loaded microparticles (SO-M) were produced (∼75% yield) by spray drying. The average diameter and polydispersity Index (PDI) of the particles were found to be 2.3µ and 0.345. XRD spectra of SO-M showed reduction in crystallinity due to microencapsulation. After four weeks of storage, a moderate (∼12%) decrease in the EPA and DHA content and a low PV of 5.5±0.51meq/kg oil in SO-M demonstrated good oxidative stability. Satisfactory encapsulation efficiency (84±0.84%) and loading efficiency (67±0.51%) values, also demonstrated the suitability of Va-g-Ch for microencapsulation of sardine oil.

Optimization of process parameters for the production of collagen peptides from fish skin (Epinephelus malabaricus) using response surface methodology and its characterization.

The study optimized the hydrolysis conditions for the production of fish collagen peptides from skin of Malabar grouper (Epinephelus malabaricus) using response surface methodology. The hydrolysis was done with enzymes pepsin, papain and protease from bovine pancreas. Effects of process parameters viz: pH, temperature, enzyme substrate ratio and hydrolysis time of the three different enzymes on degree of hydrolysis were investigated. The optimum response of degree of hydrolysis was estimated to be 10, 20 and 28% respectively for pepsin, papain and protease. The functional properties of the product developed were analysed which showed changes in the properties from proteins to peptides. SDS-PAGE combined with MALDI TOF method was successfully applied to determine the molecular weight distribution of the hydrolysate. The electrophoretic pattern indicated that the molecular weights of peptides formed due to hydrolysis were nearly 2 kDa. MALDI TOF spectral analysis showed the developed hydrolysate contains peptides having molecular weight in the range below 2 kDa.

Multiresidue analysis of multiclass pesticides and polyaromatic hydrocarbons in fatty fish by gas chromatography tandem mass spectrometry and evaluation of matrix effect.

This paper reports a selective and sensitive method for multiresidue determination of 119 chemical residues including pesticides and polyaromatic hydrocarbons (PAH) in high fatty fish matrix. The novel sample preparation method involved extraction of the target analytes from homogenized fish meat (5 g) in acetonitrile (15 mL, 1% acetic acid) after three-phase partitioning with hexane (2 mL) and the remaining aqueous layer. An aliquot (1.5 mL) of the acetonitrile layer was aspirated and subjected to two-stage dispersive solid phase extraction (dSPE) cleanup and the residues were finally estimated by gas chromatography mass spectrometry with selected reaction monitoring (GC-MS/MS). The co-eluted matrix components were identified on the basis of their accurate mass by GC with quadrupole time of flight MS. Addition of hexane during extraction and optimized dSPE cleanup significantly minimized the matrix effects. Recoveries at 10, 25 and 50 µg/kg were within 60-120% with associated precision, RSD<11%.