Major dietary lipids in nutrition and health.

In this chapter, an overview of the major lipids in the diet with emphasis in nutritional aspects is provided. Triacylglycerols, i.e., glycerol esterified with three fatty acids, are the predominant constituents in dietary lipids. Therefore, this chapter focuses on the nature and nutritional significance of the main fatty acids in the diet and their possible modifications during food processing and commercialization. The main fatty acids in dietary lipids are grouped into saturated, monounsaturated and polyunsaturated fatty acids. Nutritional implications, the latest intervention trials and health recommendations will be discussed. A brief description of the major sources of lipids in the diet is included, oils and fats standing out. Other food sources shortly commented are milk and dairy products, meat, poultry and eggs, fish, and structured lipids designed to improve functional and nutritional properties. Modifications of fatty acids as a result of processing and commercialization are discussed because of their great relevance for their health implications, especially oxidation compounds and trans fatty acids.

Effect of consumer's decisions on acrylamide exposure during the preparation of French fries. Part 2: Color analysis.

Two observational tests were designed to investigate the influence of consumer decisions during the preparation of French fries from fresh potatoes on acrylamide formation. In both tests, color was of paramount importance to volunteers with regards to the decision to stop the frying process. CIE-Lab* color parameters and visual color assessments of French fries were associated with general acrylamide content and its classification according to the EU benchmark levels (BL, 500 µg/kg). Binary logistic regression analysis revealed that color parameter a* was the main factor in determining the probability of acrylamide content being above BL, regardless of the culinary practices applied. A cut-off of 0.855 for a* produced the greatest sensitivity (81.1%) and specificity (99.9%) for classifying samples with acceptable BL of acrylamide content. An increase of one unit of a* more than quadruple the risk of acrylamide content not falling within BL. When no external color reference was provided, volunteers misclassified 33.6% of fries as having a golden color. Harmonized criteria based on a reference color chart that indicates a golden color are necessary for producing fries with reduced acrylamide contents and, in this way, limit the risk of exposure to acrylamide in domestic settings.

Effect of consumer's decisions on acrylamide exposure during the preparation of French fries. part 1: Frying conditions.

Variability in home-cooking practices affects dietary exposure to acrylamide, limiting risk evaluation. Two observational tests (controlled and randomized) involving 127 volunteers was designed to investigate the influence of consumer decisions on acrylamide formation during the preparation of French fries. Consumer practices were recorded during pre-frying, frying and post-frying stages. Reducing sugar content, asparagine, moisture, acrylamide, moisture, weight loss and color were evaluated. In the controlled assay, mean acrylamide content was 508 µg/kg and volunteers took a mean frying time of 91.9 s (87.5-96.4, C.I. 95%). The narrow confidence interval of 8.9 s represented an increase of 120 µg/kg in the acrylamide content of the fried potato. Average acrylamide content in the randomized assay (215 µg/kg, 150-280 µg/kg, C.I. 95%) was significantly lower than in the controlled assay. Amongst the culinary practices applied for the potato variety evaluated, washing of the potato strips significantly reduced acrylamide content in French fries. The percentage of samples with acrylamide lower than the benchmark value (500 µg/kg) was 54% and 93% for the controlled and randomized assays, respectively. Estimated average dietary exposure to acrylamide from French fries in adults was 5.65 µg/day, which corresponds to a margin of exposure of 2105 for carcinogenicity.

RP-UHPLC-DAD-QTOF-MS As a Powerful Tool of Oleuropein and Ligstroside Characterization in Olive-Leaf Extract and Their Contribution to the Improved Performance of Refined Olive-Pomace Oil during Heating.

Since olive leaf is a potential source of phenolic fraction that is assumed to have good antioxidative effects, we purposed to add its extract to the refined olive-pomace oil during heating to increase its oxidative stability. RP-UHPLC-DAD-QTOF-MS was employed to characterize the phenolic fraction.The oil samples were evaluated by measuring the polymers and the polar compounds and thus detecting specific oxidized compounds. Using this approach, the results showed that incorporating olive leaf extract in refined oil significantly reduced the formation of polymers from 14.39% to 10.45% and the oxidation state by the variation of extinction ΔK from 3.02 to 2.29 during 20 h of heating compared to unenriched oil. This study has proven that the use of natural substances is an opportunity to extend the life of refined oils.

Acrylamide in French fries prepared at primary school canteens.

Children are one of the most exposed groups to dietary acrylamide with 'potato fried products' that account for up to half the total exposure to this contaminant. Acrylamide was measured in French fries prepared in 31 primary school canteens randomly recruited from different Spanish regions. The mean content was 329 µg kg-1 (from <20 to 4000 µg kg-1). French fries prepared from frozen par-fried potatoes reported a lower acrylamide content than those from fresh potatoes, 229 and 460 µg kg-1, respectively. Only 15.7% of samples were above the benchmark levels established by the EU Regulation 2017/2158 (500 µg kg-1). Significant differences were found according to the color of toasted (2274 µg kg-1), dark-golden (463 µg kg-1), golden (134 µg kg-1) and light-golden (52 µg kg-1) French fries. All the samples that were golden and light-golden showed acrylamide content below the threshold. The chromatic parameter a* was used as a rough classification of the French fries according to the benchmark level. Both educational initiatives intended for food operators and managerial-technical criteria that include the code of frying practices at public food service establishments should consider the golden color as the target for the end-point of frying. Acrylamide exposure will be reduced and, therefore, the risk linked to French fries consumption. This fact is especially relevant in establishments that prepare food for schoolchildren and would help to provide healthier diets, not only from a nutritional point of view but also from the reduction of chemical contaminants.

Acrylamide content in French fries prepared in households: A pilot study in Spanish homes.

An observational cross-sectional pilot study in 73 Spanish households was conducted to evaluate the impact of consumer practices on the formation of acrylamide during the preparation of French fries from fresh potatoes applying one stage frying. 45.2% of samples presented acrylamide concentrations above the benchmark level for French fries (500 µg/kg). 6.9% of samples exceeded 2000 µg/kg and the 95th percentile was 2028 µg/kg. The median and average values were significantly higher than the EFSA report for this food category, suggesting that the total exposure to acrylamide by the population could be underestimated. In this randomised scenario of cooking practices, the content of reducing sugar and asparagine did not explain the acrylamide levels. However, the chromatic parameter a∗ of the fried potato was a powerful tool to classify the samples according to the acrylamide benchmark level regardless of the agronomical characteristics of the potato or the consumer practices.

Concentrates of triterpenic acids obtained from crude olive pomace oils: characterization and evaluation of their potential antioxidant activity.

BACKGROUND: Pentacyclic triterpenic acids (TA) are phytochemicals of increasing nutritional interest owing to their bioactive properties, such as anti-inflammatory, antitumoral, antihyperglycemic and hepatoprotective. Crude olive pomace oils constitute a non-exploited significant source of these compounds. In the present study, concentrates of TA were extracted and characterized from crude olive pomace oils that were obtained by centrifugation and subsequent solvent extraction, respectively. Specifically, the concentrates were obtained from the byproduct generated in the filtration of the oils. The solids were subjected to Soxhlet extractions with hexane to remove the residual oil and then with ethanol for the TA extraction. RESULTS: Concentrates containing 850-980 g kg-1 TA were isolated from the oils obtained by centrifugation, whereas those isolated from oils obtained by hexane extraction presented levels of TA that ranged from 510 to 900 g kg-1 . Oleanolic (OA) and maslinic (MA) acids were the TA found in the concentrates. The relative contents of OA and MA were, respectively, 30:70 (w/w) and 77:23 (w/w). All concentrates also presented phenolic compounds at levels of g kg-1 and displayed slight antioxidant properties. CONCLUSION: Concentrates of TA, containing MA and OA, can be readily obtained from a byproduct generated by filtration of crude olive pomace oils. Concentrates isolated from oils obtained by centrifugation were rich in MA, whereas those from oils extracted with hexane were rich in OA. The concentrates showed slight antioxidant properties that can be mainly attributed to the presence of phenolic compounds and not to TA. © 2018 Society of Chemical Industry.

Effectiveness of α-, γ- and δ-Tocopherol in a CLA-Rich Oil.

Conjugated linoleic acid (CLA) is a mixture of positional and geometric isomers of octadecadienoic acid with conjugated double bounds. Positive health properties have been attributed to some isomers, such as anticarcinogenic activity, antiartherosclerotic effects and reduction of body fat gain. Hence, oils rich in CLA such as Tonalin(®) oil (TO), normally obtained through alkaline isomerization of safflower oil (SO), an oil rich in linoleic acid (LA), are currently used in functional foods. However, special care must be taken to protect them from oxidation to ensure the quality of the supplemented foods. The objective of this work was to evaluate the oxidation and effectiveness of different tocopherol homologues (α-, γ- and δ-), alone or in combination with synergists (ascorbyl palmitate and lecithin), in TO compared to SO at different conditions, ambient temperature (25 °C) and accelerated conditions in Rancimat (100 °C). The oils, the oils devoid of their antioxidants and the latter containing the antioxidants added were assayed. Results showed great differences between SO and TO in terms of formation of hydroperoxides and polymers and also in the effectiveness of tocopherols to delay oxidation. TO showed higher levels of polymerization and, in general, the effectiveness of tocopherol homologues, alone or in combination with synergists, was also lower in the TO.