Phosphatidylcholine and dihydrocaffeic acid amide mixture enhanced the thermo-oxidative stability of canola oil

Use of egg yolk phospholipids to improve the thermal-oxidative stability of fatty acids, capsaicinoids and carotenoids in chili oil

Phospholipids can act as antioxidants in food. In this study, egg yolk phospholipids (EPL) and sunflower oil were utilized in making chili oil, and proton nuclear magnetic resonance spectroscopy was employed to quantify the concentrations of fatty acyl groups, carotenoids, capsaicinoids in chili oil according to their specific signals in the spectra. The results showed that the changes in the concentrations of fatty acyl groups in the control samples were greater than those in the EPL-treated samples at the same frying temperature, while the contents of carotenoids and capsaicinoids were significantly lower than those of the EPL-treated samples when fried at 150 °C (p < 0.05). Two-way ANOVA indicated that frying temperature and EPL treatment, as well as their interaction had significant impacts on the thermal-oxidative stability of chili oil (p < 0.05). The results suggest that EPL may act as antioxidants during frying, and EPL can improve the thermal-oxidative stability of chili oil.

Frying Performance of Gallic Acid and/or Methyl Gallate Accompanied by Phosphatidylcholine

This study shows the possibility of using gallic acid (GA) and/or methyl gallate (MG) accompanied by phosphatidylcholine (PC) instead of tert-butylhydoquinone (TBHQ) for frying purposes. The antioxidants and PC were added in the concentrations of 1.2 mM and 500-2000 mg/kg, respectively. Oxidative stability index (OSI) and the kinetics of change in conjugated dienes (LCD), carbonyls (LCO), and acid value (AV) were used to assess the antioxidative treatments. GA alone and GA/MG (50:50) plus PC at 2000 mg/kg yielded the same OSI as that of TBHQ (18.4 h). The latter was of the highest frying performance in preventing the formation of LCD (rn = 0.0517/h and tT = 10.6 h vs. rn = 0.0976/h and tT = 4.5 h for TBHQ), LCO (rn = 0.0411/h and tT = 12.7 h vs. rn = 0.15/h and tT = 4.3 h for TBHQ), and hydrolytic products (AVm = 37.8 vs. 24.0 for TBHQ); rn: normalized the maximum rate of LCD/LCO accumulation; tT: the time at which the rate of LCD/LCO accumulation is maximized; AVm: quantitative measure of hydrolytic stability.

Migration of tocopherols from the oil phase to the oil-water interface using phospholipids improved the oxidative stability of O/W emulsions

The purpose of this research was to effectively migrate tocopherols (T) to the oil-water interface layer (oxidation site) by combining hydrophobic T with amphiphilic phospholipids (P) to improve the oxidative stability of O/W emulsions. Firstly, it was confirmed that the antioxidant ability of TP combinations exhibited synergistic effects in O/W emulsions by measuring lipid hydroperoxides and thiobarbituric acid-reactive species. Moreover, the introduction of P into O/W emulsions to improve the distribution of T at the interfacial layer was confirmed by centrifugation and confocal microscopy methods. Subsequently, the possible mechanisms of synergistic interaction between T and P were described by fluorescence spectroscopy, isothermal titration calorimetry, electron spin resonance, quantum chemical methods and the variation of minor constituents during storage. This research revealed an in-depth insight into the antioxidant interaction mechanism of TP combinations using experimental and theoretical approaches, which provided theoretical guidance for developing emulsion products with better oxidative stability.

Dihydrocaffeic Acid-Is It the Less Known but Equally Valuable Phenolic Acid?

Dihydrocaffeic acid (DHCA) is a phenolic acid bearing a catechol ring and three-carbon side chain. Despite its being found in minor amounts in numerous plants and fungi of different origins, it has attracted the interest of various research groups in many fields of science, from food to biomedical applications. The review article presented herein aims to show a wider audience the health benefits and therapeutic, industrial, and nutritional potential of dihydrocaffeic acid, by sheddinglight on its occurrence, biosynthesis, bioavailability, and metabolism. The scientific literature describes at least 70 different derivatives of dihydrocaffeic acid, both those occurring naturally and those obtained via chemical and enzymatic methods. Among the most frequently used enzymes that were applied for the modification of the parent DHCA structure, there are lipases that allow for obtaining esters and phenolidips, tyrosinases used for the formation of the catechol ring, and laccases to functionalize this phenolic acid. In many studies, both in vitro and in vivo, the protective effect of DHCA and its derivatives on cells subjected to oxidative stress and inflammation were acknowledged.

Effect of new antioxidants: phenolipids on quality of fried French fries and rapeseed oil

The purpose of this work was to evaluate the effect of five novel synthetic antioxidants: octyl sinapate (OSA), octyl ferulate (OFA), octyl caffeate (OCA), cetyl sinapate (CSA) and cetyl ferulate (CFA) added to refined rapeseed oil for the first time on antioxidant activity (AA) and total phenolic content (TPC) in French fries. French fries after frying in enriched oils had higher the AA determined by three assays: 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS = 2907-20,029 μmol TE/100 g), 2,2-diphenyl-1-picrylhydrazyl (DPPH = 657-6886 μmol TE/100 g), ferric reducing antioxidant power (FRAP = 332-2659 μmol TE/100 g) and total phenolic content (TPC = 44-378 mg SA/100 g) than those prepared in refined rapeseed oil (ABTS = 2146 μmol TE/100 g, DPPH = 403 μmol TE/100 g, FRAP = 218 μmol TE/100 g, TPC = 14 mg SA/100 g). Moreover, the presence of phenolipids in rapeseed oil decreased the oil content in fried French fries by 22-45%. However, the AA and TPC in the fortified oils significantly increased, whereas slower changes in oxidation parameters of supplemented oils after frying were observed. A new lipophilic antioxidants can be useful for the development of management system for the preparation of French fries and the prolongation of frying oil shelf life.

Antioxidant Potential and the Characterization of Arachis hypogaea Roots

Arachis hypogaea roots are used as traditional Chinese medicine to treat different ailments, and the present study involves the exploration and comparison of phenolic profile and antioxidant activities (ABTS+ and DPPH assay) of A. hypogaea root extract in different solvents. 70% aqueous acetone and 70% aqueous ethanol were proved to be the best solvents to recover total phenolic compounds, with a yield of 42.59 ± 1.96 and 41.34 ± 0.92 mg/g dry weight of extract, respectively. ABTS+ radical scavenging activity was the highest in 70% aqueous ethanol, while the absolute methanol extract showed the highest DPPH radical scavenging activity (29.50 ± 2.19 μg/mL). Furthermore, phytochemical profiling of 70% acetone extract of A. hypogaea roots was performed by LC-ESI-TOF-MS analysis which in turn indicated the presence of diverse compounds in the A. hypogaea root extract, namely, quinones, stilbenoids, and flavones and flavonoid glucosides.

Influence of natural and synthetic antioxidants on the degradation of Soybean oil at frying temperature

The effect of several natural and synthetic antioxidants to retard the formation of polar compounds and thermo-oxidation at prolonged frying temperatures was studied. Antioxidants, including butyl hydroxyl toluene (BHT), ter-butyl hydroxyquinone (TBHQ), α- and γ-tocopherols, tocopherol mixture (α, β, γ and δ), sesamol, β-sitosterol, β-sitostanol, γ-oryzanol, curcumin, rosemary extract and sucrose acetate isobutyrate (SAIB) were tested in refined soybean oil without added any additives recovered from refinery. Rosemary extract and SAIB were showed a considerable effect on both polar compound formation and secondary oxidation. These compounds increased the oxidative stability of oil for more than 30 % compared to conventional synthetic antioxidants. Oils treated with SAIB showed higher color retention after 6 h heating compared to the oils added with BHT, TBHQ and tocopherols. Curcumin, sesamol and γ-oryzanol showed higher antioxidant potential compared to other antioxidants. Preliminary results obtained from this study have clearly demonstrated that SAIB and rosemary extracts are more commercially viable antioxidants to increase the stability of frying oils.