Effects of Dietary Fat Oxidation Products and Flavonols on Lipoprotein Oxidation

Various studies suggest that oxidative modifications of low density lipoprotein (LDL), and also other lipoproteins, have an important role in the development of atherosclerosis. In addition to the oxidation products formed endogenously, oxidised triacylglycerols (TAG) and oxysterols in the diet contribute to the oxidised lipoproteins found in circulation. However, studies on both the effect of oxidised dietary lipids on lipoprotein lipid oxidation and the reactions that modify oxidised fat after ingestion have been scarce. Studies on the effects of dietary antioxidants on the lipid oxidation in vivo and the risk of atherosclerosis have been inconclusive. More clinical trials are needed to test the importance of lipoprotein oxidation as a cardiovascular risk factor in humans. In the recent years, various methods have been optimised and applied to the analysis of lipid oxidation products in vivo, and information on the molecular structures of oxidised lipids in plasma, lipoproteins and atherosclerotic plaques has started to accumulate. However, specific structures of oxidised TAG molecules present in these tissues and lipoprotein fractions have not been investigated earlier. In the orginal research in this thesis, an approach based on highperformance liquid chromatographyelectrospray ionisationmass spectrometry (HPLCESIMS) and baseline diene conjugation (BDC) methods was used in order to investigate lipid oxidation level and oxidised TAG molecular structures in pig and human lipoproteins after dietary interventions. The approach was optimised with human LDL samples, which contained various oxidation products of TAG. LDL particles of hyperlipidaemic subjects contained an elevated amount of conjugated dienes. In the pig studies, several oxidised TAG structures with hydroxy, keto, epoxy or aldehydic groups were found in chylomicrons and VLDL after diets rich in sunflower seed oil. Also, the results showed that oxidised sunflower seed oil increased the oxidation of lipoprotein lipids and their TAG molecules. TAG hydroperoxides could be detected neither in the small intestinal mucosa of the pigs fed on the oxidised oil nor in their chylomicrons or VLDL.6 In the clinical studies, dietary flavonol aglycones extracted from sea buckthorn berries did not have an effect on lipoprotein lipid oxidation and other potential risk factors of atherosclerosis, but their absorption was demonstrated. Oil supplementation seemed to increase the bioavailability of the flavonols. Oxidised TAG molecules were detected in LDL particles of the subjects after both flavonol and control diets.Siirretty Doriast

Effects of Aromatic Herb Flavoring on Carotenoids and Volatile Compounds in Edible Oil From Blue Sweet Lupin (Lupinus angustifolius)

This study investigates the carotenoid and volatile compositions of one sample of lupin oil (Lupinus angustifolius) and five samples of lupin oil flavored with aromatic herbs, namely, basil, chives, rosemary, sage, and thyme. Flavored oils are obtained by macerating lupin oil with the herbs for 15 days, in the dark at 151 degrees C. Overall 11 carotenoids are identified by HPLC-DAD-MS-(APCI). (all-E)-Lutein and -carotene are the most abundant. Thyme flavored oil results the richest in carotenoids, with a cumulative carotenoid content of 19513gmL(-1). Volatile organic compounds are detected by HS-SPME-GC/MS analysis. Overall, 50 aroma compounds are determined, with alcohols, furans, and terpenoids being the most abundant classes. Chives flavored oil is the only sample to provide organosulfur compounds. Qualitatively, terpenoids are responsible for great differences among the samples, since unique terpenoid profiles are observed, for example, isoterpinolene is detected only in sage flavored oil, -myrcene in rosemary flavored oil, and thymol in thyme flavored oil. The relative odor activity value (ROAV) is determined and employed to evaluate the contributions of the single compounds to the overall odor. The compounds with the greatest odor activity are 3-hexen-1-ol, hexanal, -pinene, eucalyptol, and 2-pentylfuran.Practical Applications: Aromatic herbs have been traditionally used to enhance the flavor of food. The effects of herbs addition on lupin products has not been investigated yet. Additionally, this is the first study that explores some quality characteristics of commercial lupin oil. Data indicate that the maceration of lupin oil with aromatic herbs has limited effects on the content of total carotenoids, nonetheless, it modifies markedly the composition and relative proportions of the volatile organic compounds, and likely the overall aromas. Consumers are generally not familiar with the culinary use of lupin oil, nevertheless, the aromatization with herbs could increase its use. Lupin oil results rich in carotenoids. This is useful information for the production of functional products with healthy properties. Lupin oil can be recommended as a carotenoid-rich product and as an alternative to more traditional table oils. Data from this study can contribute to the economic valorization of lupin oil

Non-destructive assessment of vitamin C in foods: a review of the main findings and limitations of vibrational spectroscopic techniques

The constant increase in the demand for safe and high-quality food has generated the need to develop efficient methods to evaluate food composition, vitamin C being one of the main quality indicators. However, its heterogeneity and susceptibility to degradation makes the analysis of vitamin C difficult by conventional techniques, but as a result of technological advances, vibrational spectroscopy techniques have been developed that are more efficient, economical, fast, and non-destructive. This review focuses on main findings on the evaluation of vitamin C in foods by using vibrational spectroscopic techniques. First, the fundamentals of ultraviolet-visible, infrared and Raman spectroscopy are detailed. Also, chemometric methods, whose use is essential for a correct processing and evaluation of the spectral information, are described. The use and importance of vibrational spectroscopy in the evaluation of vitamin C through qualitative characterization and quantitative analysis is reported. Finally, some limitations of the techniques and potential solutions are described, as well as future trends related to the utilization of vibrational spectroscopic techniques

Effect of daily light integral treatments on free amino acids and sugars contributing flavor and acrylamide formation in potato tubers of Solanum tuberosum L.

To study the effect of photoperiodic conditions on the chemical composition of potato tubers, seven cultivars, grown under controlled conditions, were evaluated for the content of free amino acids (FAA) and sugars. The differences in these compounds may have an effect on the susceptibility of acrylamide formation during potato processing as well as on the flavor profile of potato products. Tubers were produced in growth chambers under two artificially induced photoperiods; 8 h light and 15 h light per day, resulting in conditions with two different daily light integral (DLI) levels. The photoperiodic treatments influenced the total FAA and free sugar contents and composition. Of the analyzed 19 FAAs, the concentrations of 14 FAAs were significantly lower in tubers exposed to the 15 h light period compared to 8 h light, whereas the glucose content was significantly higher. The total FAA concentrations were 15–46% lower and the glucose concentrations 6–64% higher in the seven cultivars exposed to the 15 h light conditions than in those grown in 8 h light

Supercritical CO2 Extraction of Triterpenoids from Chaga Sterile Conk of Inonotus obliquus

Triterpenoids are among the bioactive components of Chaga, the sterile conk of the medicinal fungus Inonotus obliquus. Supercritical fluid extraction of Chaga triterpenoids was carried out with supercritical CO2, while a modified Folch method was used as a comparison. Three temperature-pressure combinations were tested varying between 314-324 K (40-50 degrees C) and 281-350 bars, using time- and volume-limited extractions. Six triterpenoids were identified with GC-MS and quantified with GC-FID: ergosterol, lanosterol, beta-sitosterol, stigmastanol, betulin, and inotodiol. The Folch extraction resulted in recovery of trametenolic acid, which was not extracted by supercritical CO2. Inotodiol was the major triterpenoid of all the extracts, with a yield of 87-101 mg/100 g and 139 mg/100 g, for SFEs and the Folch method, respectively. The contents of other major triterpenoids, lanosterol and ergosterol, varied in the ranges 59-63 mg/100 g and 17-18 mg/100 g by SFE, respectively. With the Folch method, the yields were 81 mg/100 g and 40 mg/100 g, respectively. The highest recovery of triterpenoids with SFE in relation to Folch was 56% and it was obtained at 324 K (50 degrees C) and 350 bar, regardless of extraction time or volume of CO2. The recoveries of lanosterol and stigmastanol were unaffected by SFE conditions. Despite the lower yield, SFE showed several advantages including shorter extraction time and less impact on the environment. This work could be a starting point for further studies on green extraction methods of bioactive triterpenoids from Chaga

Effects of different drying temperatures on the content of phenolic compounds and carotenoids in quinoa seeds (Chenopodium quinoa) from Finland

This investigation studied the effects of different drying temperatures on the content of phenolic compounds and carotenoids in quinoa seeds (Chenopodium quinoa) from Finland. Five drying temperatures were applied to reach a dry matter content of 94–95% w/w: room temperature, 40, 50, 60, and 70 °C. The process performed at 70 °C allowed the greatest recovery of total phenolic compounds, 994 ± 28 mg kg−1. Ferulic acid and quercetin were the main phenolics identified. The drying process performed at 60 °C allowed the greatest recovery of cumulative carotenoids, 2.39 ± 0.05 mg kg−1. The carotenoids identified were xanthophylls, e.g., lutein, zeaxanthin and neochrome. The use of heat impacted positively on the phytochemical composition of quinoa. The concentration of phenolics and carotenoids increased steadily with the rise in drying temperature. Results obtained provide scientific knowledge that can be used by producers to increase the availability of such phytochemicals in quinoa seeds

Profile and content of residual alkaloids in ten ecotypes of Lupinus mutabilis Sweet after aqueous debittering process

Universidad Nacional Agraria La Molina. Facultad de Industrias AlimentariasThe evaluation of the level of alkaloids in edible Lupinus species is crucial from a food safety point of view. Debittering of lupin seeds has a long history; however, the control of the level of alkaloids after processing the seeds is typically only evaluated by changes in the bitter taste. The aim of this study was to evaluate the profile and residual levels of quinolizidine alkaloids (QA) in (Lupinus mutabilis Sweet) after aqueous debittering process. Samples from 10 ecotypes from different areas of Peru were analyzed before and after the process. Based on results obtained by gas chromatography and mass spectrometry, from eight alkaloids identified before the debittering process, only small amounts of lupanine (avg. 0.0012 g/100 g DM) and sparteine (avg. 0.0014 g/100 g DM) remained in the seeds after the debittering process, and no other alkaloids were identified. The aqueous debittering process reduced the content of alkaloids to levels far below the maximal level allowed by international regulations (≤ 0.2 g/kg DM)

Oxidative stability, oxidation pattern and α-tocopherol response of docosahexaenoic acid (DHA, 22:6n-3)-containing triacylglycerols and ethyl esters

DHA is most often used in supplements either in its triacylglycerol or ethyl ester form. Currently, there is only little published data on the differences in the oxidative stability and α-tocopherol response between the two lipid structures, as well as on the oxidation patterns of pure DHA. This study investigated the oxidative stability, α-tocopherol response and oxidation pattern of DHA incorporated in triacylglycerols and as ethyl esters with an untargeted approach after oxidation at 50 °C in the dark. Liquid and gas chromatographic methods with mass spectrometric detection and nuclear magnetic resonance spectroscopy were applied. DHA was more stable in triacylglycerols than as ethyl esters without α-tocopherol addition. With α-tocopherol added the opposite was observed. The oxidation products formed during triacylglycerol and ethyl ester oil oxidation were mostly similar, but also some structure-related differences were detected in both volatile and non-volatile oxidation products