Novel approach to study fish oil oxidation using 1H nuclear magnetic resonance spectroscopy

Advance in aldehydes derived from lipid oxidation: A review of the formation mechanism, attributable food thermal processing technology, analytical method and toxicological effect

The aldehydes derived from lipid oxidation are highly active electrophilic compounds including saturated aldehydes, dialdehydes, olefin aldehydes and hydroxyl aldehydes. The active groups like carbonyls, C=C bond, and hydroxyl groups make them prone to participate in chemical reactions with protein, phospholipids, which can further affect food properties. In addition, aldehydes can attack the nucleic acids and thiol group of endogenous antioxidants, result in oxidative stress and biological damage of cells, which usually serve as the direct trigger of various diseases. However, their structure-activity relationship has not received enough attention. Therefore, to provide a comprehensive understanding of reactive aldehydes on food safety and human health, the formation mechanism of aldehydes, attributable fundamental thermal processing, analytical methods, and toxicological effects based on the structure-activity relationship, have been reviewed and discussed. It was indicated that aldehydes generation exerted significant specificity of fatty acids substrate. Significant structure-activity relationships for the toxicological effects of aldehydes could be observed. Effective, accurate and eco-friendly detection techniques should be established based on the inherent advantages and limitations for food quality preservation and safety assurance.

Synthesis of lipophilic vitamin C and evaluation of its antioxidant performance in sunflower seed oil frying

The present study involved the synthesis and analysis of a lipophilic form of vitamin C, namely tetrabutyryl vitamin C ester (TVCE). TVCE is synthesized by a simple one-step method, combining the advantages of VC and butyric acid. Its antioxidant efficacy on sunflower seed oil frying was evaluated by assessing lipid oxidation parameters including peroxide number (POV), carbonyl number (CV), and paraniline number (pAV). Furthermore, changes in the fatty acid composition of the oil were monitored using techniques such as infrared spectroscopy (IR), nuclear magnetic resonance (NMR), and gas chromatography (GC). The findings demonstrated that lipophilic vitamin C exhibited superior protection against oxidation during frying compared to vitamin E, suggesting that it may be an effective fat-soluble antioxidant. The study provides a new field for the utilization of vitamin C and a new idea for the development of efficient antioxidants.

Asterias Rolleston starfish gonad lipids: A novel source of Omega-3 fatty acids - assessment of major components and their antioxidant activities

The major lipids and antioxidant activities of Asterias rolleston gonad lipids were evaluated systematically. Major lipids of A. Rolleston gonad lipids were triacylglycerols (TAGs) and phospholipids (PLs). Total lipids were composed of 15.62% of polyunsaturated fatty acids (PUFAs), and 40.81% of monounsaturated fatty acids (MUFAs). The most abundant PUFA were C20:5n-3 (EPA) (6.28%) and C22:6n-3 (DHA) (5.80%). Predominantly composed of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), polar lipids were rich in PUFAs and could contain up to 34.59% EPA and DHA, and PE and PI (phosphatidylinositol) were also found to be the main carriers of EPA and ARA (arachidonic acid) in polar lipids. The MUFA and PUFA of Sn-2 in TAG are 39.72% and 30.37%, respectively. A total of 64 TAG species were identified, with Eo-P-M, Eo-Eo-M, and M-M-Eo being the main TAGs components. Moreover, A. rollestoni gonad lipids exhibited potent radical scavenging activities and reducing power in a dose-dependent manner.

Synthesis of lipoic acid ferulate and evaluation of its ability to preserve fish oil from oxidation during accelerated storage

Lipoic acid ferulate (LAF) was synthesized and its anti-free radical ability in vitro was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonicacid) (ABTS) assays. Protective effects of LAF in stabilizing fish oil were tested, compared to antioxidants such as lipoic acid, ferulic acid and tert-butylhydroxyquinone (TBHQ) by measuring peroxide values, thiobarbituric acid reactants, p-anisidine values, nuclear magnetic resonance (NMR) spectra and gas chromatography-mass spectrometry (GC-MS) spectra of fish oil during accelerated storage (12 days, 80 °C). The inhibitory effect of these antioxidants on fish oil oxidation followed the order TBHQ ≧ LAF > ferulic acid > lipoic acid. In addition, the omega-3 polyunsaturated fatty acids were the first to be oxidized. The formation of oxidation products followed a first-order kinetic model, and the addition of LAF effectively reduced the reaction rate constants. Therefore, LAF can effectively slow down the formation of oxidative products and prolong the shelf life of fish oil.

Essential Oil Quality and Purity Evaluation via FT-IR Spectroscopy and Pattern Recognition Techniques

Essential oils are highly volatile, aromatic concentrated extracts from plants with wide applications. In this study, fast, easy-to-use attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) was combined with chemometric techniques to verify essential oils’ taxonomy and purity. Principal component analysis (PCA) clustered 30 essential oil samples into three different groups based on plant botanical family and concentration. The first group contained highly concentrated oils from the Asteraceae family, the second group contained highly concentrated oils from the Lamiaceae family, while the last group contained three highly concentrated essential oils from different botanical families and commercial-grade essential oils. Thus, commercial-grade oil samples did not cluster with the corresponding concentrated oil samples despite their similar spectral patterns or botanical family. A loading plot identified infrared (IR) bands that correspond to carbonyl, vinyl, methyl and methylene group vibrations as the most important spectral bands that can be used as marker bands for discrimination between different botanical plant family groups. Hierarchical cluster analysis (HCA) confirmed the results obtained by PCA. ATR-FTIR spectroscopy combined with chemometric algorithms provides a direct and non-destructive method for chemotaxonomic classification of medicinal and aromatic essential oils and an assessment of their purity.

Effect of red pepper (Zanthoxylum bungeanum Maxim.) leaf extract on volatile flavor compounds of salted silver carp

Chinese red pepper (Zanthoxylum bungeanum Maxim.) leaf (ZML) extract was added to salted silver carp. The effect of ZML extract on volatile compounds formation of both dorsal and ventral muscle of salted fish was investigated. Lipid oxidation of salted fish with ZML extract was alleviated with lower peroxide value (PV) and thiobarbituric acid reactive substance (TBARS) values than that of the control. Therefore, the contents of some volatile compounds formed mainly by oxidation such as benzene, methylbenzene, 1-octene-3-ol, hexanal, and methyl ketone, which attributed off-odor of salted fish, were reduced. Principal component analysis results showed that the first principal component (PC1) and the second principal component (PC2) explained 62% and 31% of total variance, respectively, and volatile compounds of the dorsal and ventral of control group differentiated from treatment group. These results showed that ZML extract can be a source of natural antioxidants and food additives for improving flavor of salted fish.

Nuclear Magnetic Resonance (NMR) Spectroscopy in Food Science: A Comprehensive Review

Nuclear magnetic resonance (NMR) spectroscopy is a robust method, which can rapidly analyze mixtures at the molecular level without requiring separation and/or purification steps, making it ideal for applications in food science. Despite its increasing popularity among food scientists, NMR is still an underutilized methodology in this area, mainly due to its high cost, relatively low sensitivity, and the lack of NMR expertise by many food scientists. The aim of this review is to help bridge the knowledge gap that may exist when attempting to apply NMR methodologies to the field of food science. We begin by covering the basic principles required to apply NMR to the study of foods and nutrients. A description of the discipline of chemometrics is provided, as the combination of NMR with multivariate statistical analysis is a powerful approach for addressing modern challenges in food science. Furthermore, a comprehensive overview of recent and key applications in the areas of compositional analysis, food authentication, quality control, and human nutrition is provided. In addition to standard NMR techniques, more sophisticated NMR applications are also presented, although limitations, gaps, and potentials are discussed. We hope this review will help scientists gain some of the knowledge required to apply the powerful methodology of NMR to the rich and diverse field of food science.

Detection of Adulteration in Canola Oil by Using GC-IMS and Chemometric Analysis

The aim of the present study was to detect adulteration of canola oil with other vegetable oils such as sunflower, soybean, and peanut oils and to build models for predicting the content of adulterant oil in canola oil. In this work, 147 adulterated samples were detected by gas chromatography-ion mobility spectrometry (GC-IMS) and chemometric analysis, and two methods of feature extraction, histogram of oriented gradient (HOG) and multiway principal component analysis (MPCA), were combined to pretreat the data set. The results evaluated by canonical discriminant analysis (CDA) algorithm indicated that the HOG-MPCA-CDA model was feasible to discriminate the canola oil adulterated with other oils and to precisely classify different levels of each adulterant oil. Partial least square analysis (PLS) was used to build prediction models for adulterant oil level in canola oil. The model built by PLS was proven to be effective and precise for predicting adulteration with good regression (R²>0.95) and low errors (RMSE ≤ 3.23).

Barley β-d-glucan - modified starch complex as potential encapsulation agent for fish oil

The aim of the study was to examine physicochemical characteristics of fish oil microcapsules produced at different temperatures and estimate the optimal ratio of BG, CS and spray drying temperature. Only the interaction between spray drying and β-d-glucan content played a significant role in influencing the encapsulation efficiency and spray drying itself (p ≤ 0.001 and p ≤ 0.05). Temperature played a significant role in increasing particle size as well, but the coefficient for this parameter was lower (0.179). The observed differences in particle size of microcapsules could be caused by the differences in glass transition temperature of the polymers (β-d-glucan and modified starch) used as wall material. It could be seen that the lowest TBARS content was observed when the β-d-glucan in the wall material was at relatively high level (85%) with moderate temperature applied (154 °C) - 0.56 mg of malonaldehyde/kg of powder. The highest amount of EPA was present in the sample with 50% share of β-d-glucan and spray dried in 150 °C (10.22 ± 0.24). After examination of all runs of the experiment, we have made optimization study to obtain the wall material composition and spray drying temperature values which will be most appropriate for fish oil encapsulation.