Health Benefits, Antioxidant Activity, and Sensory Attributes of Selected Cold-Pressed Oils.

The consumption of cold-pressed oils (CPOs) has continuously increased due to their health-promoting compounds, such as polyunsaturated fatty acid (PUFA), tocopherols, sterols, and polyphenols. This study focused on the estimation and comparison of the physicochemical properties and sensory quality of six CPOs: linseed oil (CPLO), pumpkin oil (CPPO), milk thistle oil (CPMTO), rapeseed oil (CPRO), camelina oil (CPCO), and sunflower oil (CPSO), which are the most popular in the Polish market. These oils were analysed for their fatty acid composition (FAC), their tocopherol, sterol, polycyclic aromatic hydrocarbon (PAHs), water, and volatile matter (WVM) contents, as well as their antioxidant activity (AA) and oxidative stability parameters. Moreover, quantitative descriptive analysis (QDA) was performed to obtain detailed information on the sensory profiles and quantitative data on the CPOs' attributes that affected consumer acceptability and purchase intent. All of the analysed CPOs were rich in PUFA (27.94-68.42%). They were characterised by the different total amounts of health-beneficial compounds, such as tocopherols (TTC = 44.04-76.98 mg/100 g), sterols (TSC = 300-684 mg/100 g), and polyphenols (TPC = 2.93-8.32 mg GA/100 g). Additionally, their AA was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) methods, with results ranging between 185.36-396.63, 958.59-1638.58, and 61.93-119.21 µmol TE/100 g, respectively. However, the deterioration parameters of CPOs, such as peroxide values (PV = 0.24-4.61 meq O2/kg), p-anisidine values (pAnV = 0.39-4.77), acid values (AV = 0.31-2.82 mg KOH/g), and impurity amounts (Σ4PAHs = 1.16-8.76 µg/kg and WVM = 0.020-0.090%), did not exceed the level recommended by the Codex Alimentarius Commission. The obtained results indicated that all of the investigated CPOs are valuable sources of health-promoting bioactive compounds.

Changes in Quality of Cold-Pressed Rapeseed Oil with Sinapic Acid Ester-Gelatin Films during Storage.

In recent years, cold-pressed rapeseed oil (CPRO) has become an attractive health-beneficial product and a promising alternative to olive oil. However, a high level of unsaturated fatty acids renders a CPRO more susceptible to oxidative deterioration. Therefore, the effect of new gelatin strips with polyvinyl alcohol (GEL-PVA) and sinapic acid esters (ethyl sinapate-ESA; octyl sinapate-OSA, and cetyl sinapate-CSA) on the oxidative stability, antioxidant activity (AA), and total phenolic content (TPC) in CPRO samples was analyzed during accelerated storage. In addition, the antioxidant properties of the GEL-PVA films loaded with sinapic acid esters were studied. Interestingly, the CPRO stored in an amber glass marasca bottle containing GEL-PVA-ESA strips for 14 days had the highest AA, while the antioxidant potential was the lowest for oil without film strips. Furthermore, oil samples stored in bottles containing GEL-PVA-ESA and GEL-PVA-OSA strips for 14 days had higher antioxidant properties than the AA and TPC in fresh CPRO. Moreover, synchronous fluorescence (SF) spectroscopy and excitation-emission matrix (EEM) fluorescence spectroscopy were applied for the evaluation of changes in the main fluorescent components in CPRO samples during the accelerated storage. Overall, this study revealed that GEL-PVA films incorporated with sinapic acid esters enhanced the antioxidant potential of CPRO and delayed oxidative degradation by releasing amphiphilic antioxidants into the oil.

Effects of the Chemical Composition on the Antioxidant and Sensory Characteristics and Oxidative Stability of Cold-Pressed Black Cumin Oils.

The antioxidant capacity (AC); amounts of tocopherols, sterols, and polycyclic aromatic hydrocarbons; oxidative parameters; fatty acid composition (FAC); and sensory quality of cold-pressed black cumin oils (CPBCOs) available on the Polish market were analyzed and compared. The AC levels of the CPBCO samples were determined using four assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH = 226.8−790.1 µmol TE/100 g), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS = 385.9−1465.0 µmol TE/100 g), cupric-reducing antioxidant capacity (CUPRAC = 975.3−19,823.3 µmol TE/100 g), and Folin−Ciocalteu assays (FC = 168.1−643.7 µmol TE/100 g). The FAC scores were typical for black cumin oil, except for the sample CPBCO4, which had a higher content of α-linolenic acid (C18:3 = 23.33%), pointing to possible oil adulteration. Additionally, the concentrations of total sterols (TSC = 372 mg/100 g) and tocopherols (TTC = 42.3 mg/100 g) in this sample were higher than those for other investigated oils (TSC = 159−222 mg/100 g, TTC = 1.9−10.4 mg/100 g respectively). The oxidative stability levels (IP = 8.21−37.34 h), peroxide values (PV = 21.36−123.77 meq O2/kg), acid values (AV = 6.40−22.02 mg KOH/kg), and the sums of four specific polycyclic aromatic hydrocarbons (∑4PAHs = 4.48−46.68 µg/kg) in the studied samples differed significantly (p < 0.05). A sensory lexicon including 12 attributes was developed and applied for the sensory evaluation of oils using a quantitative descriptive analysis (QDA).

Phenolipids as new food additives: from synthesis to cell-based biological activities.

Increasing interest has been shown in phenolic compounds for enhancing food quality, but their hydrophilicity restricts application in lipophilic systems. Therefore, in this study, twelve hydroxycinnamates derivatives (alkyl and steryl esters of sinapic acid (SA), caffeic acid (CA), and ferulic acid [FA]) were synthesised and evaluated for antioxidant and cytotoxic characteristics. CA esters had the highest radical scavenging activity (RSA) analysed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Values of inhibitory concentration (IC50) of synthesised compounds were related to their structure and lipophilicity. The effect of these hydroxycinnamic acid esters on the antioxidant potential of real samples (rapeseed oil, margarine and mayonnaise) was estimated. None of the investigated derivatives significantly affected the viability of the model intestinal cells Caco2, while the octyl esters demonstrated a toxic effect at low concentrations. The synthesised esters exerted cytotoxic and anti-proliferative effects against transformed cell lines (HeLa and A549). Octyl esters were potent anticancer compounds on two human cancer cell lines. The synthesised phenolipids, as valuable and safe antioxidant additives, can find broader applications in the production of fat-based products to prevent oxidation processes, extend their shelf life and improve quality.

Steryl Sinapate as a New Antioxidant to Improve Rapeseed Oil Quality during Accelerated Shelf Life.

In recent years, steryl esters have become an attractive for the cosmetic, pharmaceutical, and food industries. Hence, the effect of exogenous antioxidant, ß-sitosteryl sinapate on oxidative stability and antioxidant activity (AA) of refined rapeseed oil was evaluated by the accelerated shelf-life test. Oxidative parameters of refined rapeseed oil-peroxide value (PV), anisidine value (p-AnV), acid value (AV), and spectrophotometric indices (K232, K268)-increased during storage. However, the addition of ß-sitosteryl sinapate caused a decrease of the primary and secondary oxidation products in the supplemented oils in comparison with the control sample. Moreover, oils with steryl ester had higher AA than oil without the synthetic antioxidant. The accelerated storage negatively affected the antioxidant potential of refined and enriched oils causing the AA decrease by 25-54% and 7-15%, respectively. Studies have consistently demonstrated beneficial associations between the presence of ß-sitosteryl sinapate in oil samples and the inhibition of their oxidative degradation under the accelerated conditions. Additionally, the possibility of using the synchronous fluorescence (SF) spectroscopy and excitation-emission matrix (EEM) fluorescence spectroscopy for identification and observing changes in main fluorescent components present in non-supplemented and supplemented rapeseed oils during the accelerated storage was attempted.

Synthesis of Steryl Hydroxycinnamates to Enhance Antioxidant Activity of Rapeseed Oil and Emulsions.

In recent years, steryl esters have found potential applications in food, pharmaceutical and cosmetic industries. Therefore, three hydroxycinnamate steryl esters (HSEs): ß-sitosteryl sinapate (ß-SSA), ß-sitosteryl caffeate (ß-SCA), and ß-sitosteryl ferulate (ß-SFA) were synthesized by chemical approach and their antioxidant activity (AA) were analyzed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assays. The values of inhibitory concentration (IC50) of each ester needed to inhibit 50% of the DPPH radical (IC50(DPPH) = 238.9, 78.3, 290.0 µmol/L for ß-SSA, ß-SCA, and ß-SFA, respectively) and ABTS radical cation (IC50(ABTS) = 174.6, 106.7, 206.0 µmol/L for ß-SSA, ß-SCA, and ß-SFA, respectively) were estimated and compared with antioxidant potential of phenolic acids. Moreover, the effect of HSEs addition in the concentrations range between 0.01% and 0.5% on the AA of refined rapeseed oil, mayonnaise and margarine was evaluated. Chemical structures of the synthesized HSEs and their concentrations strongly affect the AA of fat products. Oil and emulsions supplemented with higher concentrations of HSEs had significantly higher AA than control samples. Unfortunately, lower concentrations of HSEs (0.01% and 0.02%) did not increase the AA of fat products. However, steryl phenolates added in higher amounts can be considered as potential antioxidants delaying the oxidation processes of studied fats.