Endogenous n-Alkanes in Vegetable Oils: Validation of a Rapid Offline SPE-GC-FID Method, Comparison with Online LC-GC-FID and Potential for Olive Oil Quality Control.

The potential of endogenous n-alkane profiling for the assessment of extra virgin olive oils (EVOO) adulteration (blends with cheaper vegetable oils) has been studied by relatively few authors. Analytical methods used for this purpose often involve tedious and solvent-intensive sample preparation prior to analytical determination, making them unattractive. A rapid and solvent-sparing offline solid phase extraction (SPE) gas chromatography (GC) flame ionization detection (FID) method for the determination of endogenous n-alkanes in vegetable oils was, therefore, optimized and validated. The optimized method demonstrated good performance characteristics in terms of linearity (R2 > 0.999), recovery (on average 94%), and repeatability (residual standard deviation, RSD < 11.9%). The results were comparable to those obtained with online high-performance liquid chromatography (HPLC)-GC- FID ( RSD < 5.1%). As an example of an application to prove the potentiality of endogenous n-alkanes in revealing frauds, the data set obtained from 16 EVOO, 9 avocado oils (AVO), and 13 sunflower oils (SFO), purchased from the market, was subjected to statistical analysis and principal component analysis. Two powerful indices, namely (n-C29 + n-C31)/(n-C25 + n-C26) and n-C29/n-C25, were found to reveal the addition of 2% SFO in EVOO and 5% AVO in EVOO, respectively. Further studies are needed to confirm the validity of these promising indices.

Bioavailability Study of Isothiocyanates and Other Bioactive Compounds of Brassica oleracea L. var. Italica Boiled or Steamed: Functional Food or Dietary Supplement?

The levels of bioactive compounds in broccoli and their bioavailability following broccoli intake can be affected by the cooking procedures used for vegetable preparation. In the present pilot study, we compared the human plasma bioavailability of antioxidant compounds (ß-carotene, lutein and isothiocyanate) and of phylloquinone (vitamin K) on seven volunteers before and after the administration of boiled and steamed broccoli. Moreover, plasma isothiocyanate (ITCs) levels were also evaluated after the administration of a single dose of BroccoMax®, a dietary supplement containing GLSs with active myrosinase. Steam-cooking has been demonstrated to promote higher plasma bioavailability in ITCs than boiling (AUCSTEAMED = 417.4; AUCBOILED = 175.3) and is comparable to that reached following the intake of BroccoMax®, a supplement containing glucoraphanin and active myrosinase (AUC = 450.1). However, the impact of boiling and steaming treatment on plasma bioavailability of lipophilic antioxidants (lutein and ß-carotene) and of phylloquinone was comparable. The lutein and ß-carotene plasma levels did not change after administration of steamed or boiled broccoli. Conversely, both treatments led to a similar increase of phylloquinone plasma levels. Considering the antioxidant action and the potential chemopreventive activity of ITCs, steaming treatments can be considered the most suitable cooking method to promote the health benefits of broccoli in the diet.

Temperature Dependence of Oxidation Kinetics of Extra Virgin Olive Oil (EVOO) and Shelf-Life Prediction.

Producers have to guarantee the extra virgin olive oil (EVOO) quality characteristics reported in the Regulation (CEE) 2568/91 throughout the product shelf-life (SL). Unfortunately, due to the development of oxidative reactions, some quality indices change during storage leading to a progressive deterioration of EVOO quality. To avoid the risk of product downgrading in the virgin oil category, the development of effective shelf-life prediction models is extremely important for the olive oil industry. In this research, the accelerated shelf-life testing (ASLT) protocol was applied to evaluate the temperature dependence of selected oxidation indexes as well as to develop a shelf-life predictive model. The evolution of conventional (peroxide value, K232, K270, polyphenols, tocopherols and hexanal) and unconventional parameters (conjugated trienes and pyropheophytin a) was monitored in bottled EVOO stored in the dark at increasing temperature (25, 40, 50 and 60 °C). Accordingly, for well-packed products with reduced oxygen in headspace, the best shelf-life index allowing the ability to predict EVOO SL turned out to be K270. In addition, pyropheophytin a (%) has been shown to be more sensitive to temperature changes than the secondary oxidation indices, thus suggesting its use as a freshness indicator for storage temperatures higher than 25 °C.

Effect of different oleogelators on lipolysis and curcuminoid bioaccessibility upon in vitro digestion of sunflower oil oleogels.

Sunflower oil enriched with curcuminoid compounds (CUs) was gelled by adding 5% (w/w) saturated monoglycerides (MG), rice bran waxes (RW) or a mixture of ß-sitosterol and γ-oryzanol (PS). The resulting oleogels differed for rheological properties and firmness due to the difference in gel network structure. PS oleogel was the firmest sample followed by RW and MG ones. Upon in vitro digestion, fatty acid release as a function of digestion time was greatly affected by oleogel structure: the extent of lipolysis decreased as oleogel strength increased (PS < RW < MG). On the other hand, the nature of the oleogelator affected CUs bioaccessibility, which was lower in oleogels containing crystalline particles (MG and RW). These findings appear interesting in the attempt to develop oleogels able to control lipid digestion as well as to deliver bioactive molecules in food systems.

Effects of the Fruit Ripening Stage on Antioxidant Capacity, Total Phenolics, and Polyphenolic Composition of Crude Palm Oil from Interspecific Hybrid Elaeis oleifera × Elaeis guineensis.

In the present study, we assessed for the first time the changes in the antioxidant capacity, total phenolic content, and polyphenolic composition of interspecific hybrid palm oil extracted from Elaeis oleifera × Elaeis guineensis (O × G, Coari × La Mé cultivar) during the fruit ripening process 18, 20, 22, and 24 weeks after anthesis. A progressive decrease (p < 0.05) of phenolic content occurred during fruit development together with marked changes in polyphenol profiles. Significant negative correlations were established between antioxidant activity measured by TEAC (R = -0.954; p < 0.05) and ORAC (R = -0.745; p < 0.05) and the fruit ripening stage, while a positive correlation between total phenolic content was found using either the TEAC assay or the ORAC assay. The highest DPPH radical scavenging activity was also obtained with oils extracted at 18 WAA. These results highlight that O × G fruits of early ripeness represent a better source of phenolic compounds and may provide extracts with higher antioxidant activities when hybrid palm oil is aimed to be used as a functional ingredient for the development of food or food products with antioxidant properties.

Prunus persica var. platycarpa (Tabacchiera Peach): Bioactive Compounds and Antioxidant Activity of Pulp, Peel and Seed Ethanolic Extracts.

A comparative analysis of ethanol extracts from peel, pulp and seed of Prunus persica var. platycarpa (Tabacchiera peach) was done. The total phenol, flavonoid and carotenoid content as well as the antioxidant properties by using different in vitro assays (DPPH, ABTS, FRAP, Fe-chelating, ß-carotene bleaching test) were evaluated. Pulp extract was subjected to liquid chromatography-electrospray-tandem mass spectrometry (HPLC-ESI-MS/MS). Gallic acid, protocatechuic acid, protocatechualdehyde, chlorogenic acid, p-coumaric acid, and ferulic acid were identified as main constituents. Pulp extract was characterized by the highest total phytonutrients content and exhibited the highest antioxidant activity in all in vitro assays (IC(50) values of 2.2 µg/mL after 60 min of incubation by using ß-carotene bleaching test and 2.9 µg/mL by using Fe-chelating assay). Overall, the obtained results suggest that P. persica var. platycarpa displays a good antioxidant activity and its consumption could be promoted.

Acrylamide levels in selected Colombian foods.

Acrylamide (AA) levels in conventional (n = 112) and traditional (n = 43) Colombian foods were analysed by gas chromatography with mass spectrometry (GC/MS) detection. Samples included: infant powdered formula, coffee and chocolate powders, corn snacks, bakery products and tuber-, meat- and vegetable-based foods. There was a wide variability in AA levels among different foods and within different brands of the same food, especially for coffee powder, breakfast cereals biscuits and French fries samples. Among the conventional foods tested, the highest mean AA value was found in bakery products, such as biscuit (1104 µg kg(-1)) and wafer (1449 µg kg(-1)), followed by potato chips (916 µg kg(-1)). On the other hand, among the traditional foods, higher AA amounts were detected in fried platano (2813 µg kg(-1)) and yuca (3755 µg kg(-1)) compared to other products. Interestingly, the arepa, a traditional Colombian bakery product made with corn flour, showed a lower AA content (< 75 µg kg(-1)) when compared with similar bakery products tested, such as soft bread (102-594 µg kg(-1)), which is a made with wheat flour.

Punica granatum cv. Dente di Cavallo seed ethanolic extract: antioxidant and antiproliferative activities.

This paper aims to provide a solid base for the utilisation of pomegranate whole seed ethanolic extract (PSEE) as a nutraceutical/functional food ingredient. PSEE was tested for its antioxidant and antiproliferative activities against different human cancer cell lines. Bioactive lipid compounds were identified by studying the PSEE lipid portion. PSEE exhibited a protection of lipid peroxidation threefold higher than a positive control. PSEE showed a promising antiproliferative activity against hormone dependent prostate carcinoma LNCaP, with an IC50 value 3 times lower than the positive control vinblastine, and against human breast cancer cell lines (IC50=9.6 µg/ml). PSEE contained lipid bioactive compounds, such as neutral lipids, consisting of 72.8% punicic acid, glycolipids and phospholipids rich in essential fatty acids (α-linoleic and α-linolenic acids). Due the presence of bioactive compounds and the remarkable antiproliferative activity, the use of PSEE as a value-added ingredient in formulations of products aimed to prevent diseases, especially cancer, could be promoted.

Characterization of phospholipid molecular species and peptide molecules in wheat sprout hydroalcoholic extract.

The phospholipid molecular species and the main peptide molecules of wheat sprout hydroalcoholic extract have been fully characterized by normal-phase high performance liquid chromatography coupled online with positive electrospray ionization tandem mass spectrometry. The extract that resulted was rich in phospholipid molecular species formed by the combination of the two essential fatty acids (α-linoleic and α-linolenic). These species accounted for 51.7% of total phosphatidic acid, 47.3% of total phosphatidylethanolamine, 37.7% of total phosphatidylcholine, and 14.1% of total phosphatidylinositol. The last one showed the highest amounts of species containing palmitic acid, thus representing the most saturated phospholipid class. The extract was also shown to contain several peptide sequences with both potential antioxidant domains and interaction sites for phospholipids (i.e., H-Ala-Gly-Ser-Met-Met-Cys-NH2, H-Tyr-Met-Thr-Val-Val-Ala-Cys-NH2, etc.); this latter finding can have a highly positive impact on the poor peptides bioavailability. Because of the presence of essential fatty acids-rich phospholipids and bioactive peptides, wheat sprout hydroalcoholic extract can be considered a potential functional food ingredient.

Crude palm oil from interspecific hybrid Elaeis oleifera×Elaeis guineensis: fatty acid regiodistribution and molecular species of glycerides.

The composition and structure of triacylglycerols (TAGs) and partial glycerides of crude palm oil obtained from interspecific hybrid Elaeis oleifera×Elaeis guineensis, grown in Colombia, were fully characterised and compared to data obtained by analysing crude African palm oil. Hybridisation appears to substantially modify the biosynthesis of fatty acids (FAs) rather than their assembly in TAGs. In fact, total FAs analysis showed significant differences between these two types of oil, with hybrid palm oil having a higher percentage of oleic acid (54.6 ± 1.0 vs 41.4 ± 0.3), together with a lower saturated fatty acid content (33.5 ± 0.5 vs 47.3 ± 0.1), while the percentage of essential fatty acid, linoleic acid, does not undergo significant changes. Furthermore, 34 TAG types were identified, with no qualitative differences between African and E. guineensis×E. oleifera hybrid palm oil samples. Short and medium chain FAs (8:0, 10:0, 12:0, 14:0) were utilised, together, to build a restricted number of TAG molecular species. Oil samples from the E. guineensis×E. oleifera hybrid showed higher contents of monosaturated TAGs (47.5-51.0% vs 36.7-37.1%) and triunsaturated TAGs (15.5-15.6% vs 5.2-5.4%). The sn-2 position of TAGs in hybrid palm oil was shown to be predominantly esterified with oleic acid (64.7-66.0 mol% vs 55.1-58.2 mol% in African palm oil) with only 10-15% of total palmitic acid and 6-20% of stearic acid acylated in the secondary position. The total amount of diacylglycerols (DAGs) was in agreement with the values of free acidity; DAG types found were in agreement with the representativeness of different TAG species.