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In this work we studied the effect of polyunsaturated fatty acids (PUFAs) methyl esters on cholesterol photo-induced oxidation. The oxidative routes were modeled with a chemical reaction network (CRN), which represents the first application of CRN to the oxidative degradation of a food-related lipid matrix. Docosahexaenoic acid (DHA, T-I ), eicosapentaenoic acid (EPA, T-II ) and a mixture of both ( T-III ) were added to cholesterol using hematoporphyrin as sensitizer, and were exposed to a fluorescent lamp for 48 h. High amounts of Type I cholesterol oxidation products (COPs) were recovered (epimers 7α- and 7β-OH, 7-keto and 25-OH), as well as 5β,6β-epoxy. Fitting the experimental data with the CRN allowed characterizing the associated kinetics. DHA and EPA exerted different effects on the oxidative process. DHA showed a protective effect to 7-hydroxy derivatives, whereas EPA enhanced side-chain oxidation and 7β-OH kinetic rates. The mixture of PUFAs increased the kinetic rates several fold, particularly for 25-OH. With respect to the control, the formation of β-epoxy was reduced, suggesting potential inhibition in the presence of PUFAs. [ABSTRACT FROM AUTHOR]

Baby Foods (BFs) and Infant formulas (IFs) are the main sources of nutrition for an infant throughout the 1st year of life. Various enriched products are commercially available for parents seeking to fulfill their baby's nutritional needs. Consequently, different bioactive lipids are present in BFs and IFs, including dietary oxysterols (DOxS), whose known toxicity has been associated with mutagenicity, cancer, and other chronic diseases. In this work, we performed an exposure assessment of 25 bioactive lipids on IFs (n = 30) and BFs (n = 13) commercially available in the US. To determine dietary exposure, we used EPA's SHEDS-HT probabilistic model. Even though β-Sitosterol was the most exposed bioactive lipid with 75,410 μg/day, cholesterol was the most absorbed compound during the entire first year (19.3 mg/day). Additionally, we found 7α-hydroxycholesterol (7α-OH) as a potential DOxS biomarker of the BFs manufacturing process. This is the first time an infant's exposure assessment (including DOxS) after BFs and IFs consumption is performed, enabling much-needed information regarding these hazardous compounds and their potential effects on infants' health. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: High pressure processing (HPP) is an alternative mild-technology used in the past decades to sterilize and pasteurize food matrices such as meat and seafood. HPP obeys thermodynamic principles, namely Le Chatelier's law of equilibrium and the isostatic rule, both of which account for microbial inactivation. HPP has the advantage of ensuring reduction of pathogens and spoilage in foods, and preserving the organoleptic characteristics of the product that are compromised in traditional heat treatments. However, high pressure changes the thermodynamic equilibrium of chemical reactions. This is the case of lipid oxidation, in which kinetics is accelerated in the presence of high hydrostatic pressure. In recent years, there has been increasing focus on the response of lipid components to HPP, especially considering the deleterious outcomes that secondary products of oxidation have on the final product. The objective of this work is to review the literature on the effect of this “mild-technology” in the degradation of lipid fraction of foods. We discuss qualitative and quantitative determinations, as well as the thermodynamic and chemical interpretations underlying the phenomenon. Industrial relevance: In this work we reviewed the literature concerning the effect of high-pressure processing (HPP) on lipid oxidation. Since 1990s HPP has been used as an alternative to thermal treatments to pasteurize and sterilize food products, such as meats and seafood. Many of these raw materials have a high content of lipids (among them trialglycerols and cholesterol-derivative) that are susceptible to oxidation. During the last decade, there has been increasing interest on the response of lipid components to HPP, especially considering the deleterious outcomes that secondary oxidation-derivative molecules have on the final product. This review intends to summarize and discuss the data reported in literature, contextualizing the oxidation within the broad transformation of biological structures due to hydrostatic pressure. A better understanding of the underlying phenomena could lead to the development of predicting models which could be use in food industry. [Copyright &y& Elsevier]

Abstract: The effect of microwave heating of commercial categories of olive oil for human consumption (extra virgin olive oil [EVOo], olive–pomace oil [Po] and olive oil [Oo]) on DSC thermal properties was evaluated at different times of microwave treatment. Marked changes of DSC cooling profiles were found for EVOo and Po subjected to microwaving, with the major exotherm that shifted towards lower temperature and decreased height with increasing treatment time. Thermal properties (during DSC cooling analysis) changed in all samples: crystallisation enthalpy significantly decreased and the phase transition developed over a larger temperature range, due to more heterogeneous chemical composition of all oils that resulted from triacylglycerol lysis to the formation of lipid oxidation products. Heating profiles of EVOo and Po were also modified by microwave treatment, as the minor endotherm progressively disappeared, significantly shifting offset temperature of transition towards lower temperature. Oo did not exhibit such changes of thermal properties and phase transition profiles as described for EVOo and Po. This may be mainly related to its lower water content although the simultaneous presence of small amounts of antioxidant molecules (polyphenols) may have contributed to partially prevent thermal degradation of this oil in comparison with the others. These preliminary results suggest that DSC can be useful, not only for monitoring modifications of chemical composition with increasing microwave treatment time, but also to discriminate amongst olive oils according to their response to microwave exposure. [Copyright &y& Elsevier]

[Display omitted] • Infant formula is a critical nutritional source for infants. • Fingerprinting of lipids and oxidized compounds in Infant formulas was performed. • Dietary assessment shows high intakes of oxidized lipids. • Manufacturing of infant formula may promote lipid oxidation. Approximately two-thirds of US infants receive infant formula (IF) as a primary or sole nutritional source during the first six months of life. IF is available in a variety of commercial presentations; from a manufacturing standpoint, they can be categorized as powder- (PIF) or liquid- (LIF) based formulations. Thirty commercial IFs were analyzed in their oxidative and non-oxidative lipid profiles. We identified 7-ketocholesterol – a major end-product of cholesterol oxidation – as a potential biomarker of IF manufacturing. The statistical analysis allowed a re-classification of IF based on their metabolomic fingerprint, resulting in three groups assigned with low-to-high oxidative status. Finally, we modeled the dietary intake of cholesterol, sterols, and 7-ketocholesterol in the first year of life. The database provided in this study will be instrumental for scientists interested in infant nutrition, to establish bases for epidemiological studies aimed to find connections between nutrition and diet-associated diseases, such as sitosterolemia. [ABSTRACT FROM AUTHOR]

Food consumption can lead to the accumulation of certain chemical compounds able to exert toxic activities against humans. Of mayor interests are those molecules generated during food processing and handling, since their occurrence and distribution depend of many intrinsic and extrinsic factors. Cholesterol – a lipid constituent of mammalian cells – is the precursor of several toxic molecules known as cholesterol oxidation products (COPs). In the last decades, it has been demonstrated that food processing can dramatically trigger COPs accumulation in meats, eggs, dairy products, fish and poultry. On the other hand, countless scientific evidences have pointed out the highly toxic and pathogenic activities of COPs, from cancer stimulation to neurodegenerative disorders, via molecular mechanisms that are largely unexplored. The aim of this review is to merge the evidence on COPs accumulation in foods and their toxic activities through dietary intake, as from in vivo and in vitro studies. We consider that it is imperative to systematically monitor the formation of COPs to bridge these quantitative efforts with a risk exposure assessment on sensitive populations. [ABSTRACT FROM AUTHOR]

Abstract: A chemometric approach based on partial least (PLS) square methodology was applied to unfolded differential scanning calorimetry data obtained by 63 samples of different vegetable oils (58 extra virgin olive oils, one olive and one pomace olive oil, three seed oils) to evaluate fatty acid composition (palmitic, stearic, oleic and linoleic acids, saturated (SFA), mono (MUFA) and polysaturated (PUFA) percentages, oleic/linoleic and unsaturated/saturated ratios). All calibration models exhibited satisfactory figures of merit. Palmitic and oleic acids, as well as SFA showed very good correlation coefficients and low root mean square error values in both calibration and validation sets. Satisfactory results were also obtained for MUFA, PUFA, stearic and linoleic acids, O/L ratio in terms of percentage recoveries and relative standard deviations. No systematic and bias errors were detected in the prediction of validation samples. This novel approach could provide statistically similar results to those given by traditional official procedures, with the advantages of a very rapid and environmentally friendly methodology. [Copyright &y& Elsevier]