Lipid profiling and dietary assessment of infant formulas reveal high intakes of major cholesterol oxidative product (7-ketocholesterol).

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.

Increase in seed tannin extractability and oxidation using a freeze-thaw treatment in cool-climate grown red (Vitis vinifera L.) cultivars.

Grape seed maturation involves the gradual oxidation of tannins, decreasing excessive bitterness and astringency in wine. In cool climates, this process is limited by the short growing season, affecting wine quality. A "freeze-thaw" treatment on seeds of red vinifera cultivars at veraison and harvest was used to evaluate the effect of oxidation and extractability on seed phenolic fractions. Freezing increased the extraction of total phenolics and o-diphenols quantified from fractionation (fraction 1, vacuolar tannins; fraction 2, hydrogen bonded tannins; fraction 3, covalently bonded tannins), especially at harvest. Despite this, colorimetry, microscopy, oxidation reactivity index (ORI), and correlations between the color index and fractions indicated that freezing disrupted vacuole integrity, enhancing oxidation in the seed coat. In conclusion, vacuolar tannins (which are the main seed phenolics extracted during fermentation) were highly correlated with seed color change, potentially providing information for winemaking in cool climate regions.

Flavonoids Ability to Disrupt Inflammation Mediated by Lipid and Cholesterol Oxidation.

Flavonoids are plant secondary metabolites that act as protectants against harmful effects of UV-B radiation inasmuch as biotic stress, conferring at the same time pigmentation of fruits and leaves [67]. The term "flavonoid" refers to phenolics having a basic skeleton of diphenylpropane (C6-C3-C6), which consists of two aromatic rings linked through three carbons that usually form an oxygenated heterocycle [25, 52]. Flavonoids are broken down into several different sub-categories based on their chemical structure. The main subclasses commonly found in food items are: flavonols, flavones, flavanones, flavan-3-ols, proanthocyanidins, and anthocyanins [44, 67]. Figure 19.1 depicts the major classification of flavonoids according to their chemical structure. Their occurrence in food matrices has been extensively reviewed [39, 44], and has been subject of extensive research in the last decades. Table 19.1 contains a few examples of compounds from each of the subcategory, with the fruit (berry) in which they are commonly found. The monomeric unit of flavonoids can dimerize and polymerize to form other important high molecular weight molecules; this is the case of proanthocyanidins, that are polymers of flavan-3-ols or flavanols. Not only do these compounds act as plant protectants, but they can also be very beneficial to human health. Cohorts studies performed in the early '90 have shown that dietary consumption of flavonoids was inversely associated with morbidity and mortality from coronary heart disease [31, 32]. These findings have opened an intensive field of research on the effects of flavonoids and flavonoids-rich food extracts in cardiovascular diseases (CVD) progression, particularly in the modulating CVD-associated oxidative stress and inflammation. In this short review, we will summarize the current findings in flavonoids beneficial effects in preventing CVD through inhibition of initial stages of CVD progression. Given the magnitude of scientific literature in the field, we will focus on two strictly mechanistic aspects: inhibition of chemical-induced LDL oxidation, and the effect of flavonoids in the monocyte/macrophages activation pathways.

Metabolic fingerprinting unveils quinoa oil as a source of bioactive phytochemicals.

Quinoa is a pseudo-cereal with high phytochemical contents with proven biological and nutritional significance. In recent decades several breeding programmes have introduced new and traditional quinoa varieties to North America and other non-traditional quinoa regions, raising questions regarding variability in their secondary metabolite profiles. In this work, we have fingerprinted 28 quinoa varieties cultivated in Washington State, focussing on the poorly investigated oil fraction. We found variability in both phenolics and carotenoid contents, which is reflected in different antioxidant capacities, as measured by FRAP and DPPH. Fatty acid profiles show significant differences in palmitic acid and long-chain fatty acids. Finally, conspicuous amounts of phytosterols and squalene were found. Through factor analysis, we classified the quinoa varieties into two groups: a first comprising varieties with higher phytochemical and PUFA contents and a second group, with higher linolenic and long-chain fatty acid contents. Both groups may be suitable for potential food applications.

Enhancement of Fruit Technological Maturity and Alteration of the Flavonoid Metabolomic Profile in Merlot ( Vitis vinifera L.) by Early Mechanical Leaf Removal.

Removal of basal leaves near blooms inevitably affects grapevine balance and cluster microclimate conditions, improving fruit quality. Mechanization of this practice allows growers to save time and resources, but to our knowledge, it has not yet been compared with the manual application of this practice in a cool-climate region where seasonal temperatures frequently limit fruit technological maturity and phenolic ripening in red Vitis vinifera cultivars. In our research, berry sugar concentration was highest with prebloom mechanical treatment (PB-ME). Furthermore, metabolomics analysis revealed that PB-ME favored the accumulation of significantly more disubstituted anthocyanins and flavonols and OH-substituted anthocyanins compared with manual application. Given that vine balance was similar between treatments, increased ripening with PB-ME is likely due to enhanced microclimate conditions and higher carbon partitioning through a younger canopy containing basal leaf fragments proximal to fruit. This information provides an important strategy for consistently ripening red Vitis vinifera cultivars in cool climates.

Lipid-exchange in nanodiscs discloses membrane boundaries of cytochrome-P450 reductase.

Lipids are critical for the function of membrane proteins. NADPH-cytochrome-P450-reductase, the sole electron transferase for microsomal oxygenases, possesses a conformational dynamics entwined with its topology. Here, we use peptide-nanodiscs to unveil cytochrome-P450-reductase's lipid boundaries, demonstrating a protein-driven enrichment of ethanolamine lipids (by 25%) which ameliorates by 3-fold CPR's electron-transfer ability.

Cytochrome-P450-Induced Ordering of Microsomal Membranes Modulates Affinity for Drugs.

Although membrane environment is known to boost drug metabolism by mammalian cytochrome P450s, the factors that stabilize the structural folding and enhance protein function are unclear. In this study, we use peptide-based lipid nanodiscs to "trap" the lipid boundaries of microsomal cytochrome P450 2B4. We report the first evidence that CYP2B4 is able to induce the formation of raft domains in a biomimetic compound of the endoplasmic reticulum. NMR experiments were used to identify and quantitatively determine the lipids present in nanodiscs. A combination of biophysical experiments and molecular dynamics simulations revealed a sphingomyelin binding region in CYP2B4. The protein-induced lipid raft formation increased the thermal stability of P450 and dramatically altered ligand binding kinetics of the hydrophilic ligand BHT. These results unveil membrane/protein dynamics that contribute to the delicate mechanism of redox catalysis in lipid membrane.

Impacts of Scarification and Degermination on the Expansion Characteristics of Select Quinoa Varieties during Extrusion Processing.

Extrusion of 2 quinoa varieties, Cherry Vanilla and Black (scarified and unscarified) and a mixed quinoa variety, Bolivian Royal (scarified and degermed) were studied for their extrusion characteristics. A corotating twin-screw extruder with a 3 mm round die was used. Feed moisture contents of 15%, 20%, and 25% (wet basis) were studied. The extruder barrel temperature was kept constant at 140 °C and screw speeds were varied from 100, 150, and 200 revolutions per minutes. Process responses (specific mechanical energy, back pressure, and torque) and product responses (expansion ratio, unit density, and water absorption index/water solubility index) were evaluated. The degermed Bolivian Royal showed the highest expansion in comparison to all other varieties, attributed to its significantly low levels of fat, fiber, and protein. The scarified Cherry Vanilla resulted in the lowest expansion ratio. This was attributed to the increase in the protein content from the removal of the outer layer. The results indicate that all the varieties performed differently in the extrusion process due to their modification processes as well as the individual variety characteristics.

GC-MS Profiling of Triterpenoid Saponins from 28 Quinoa Varieties (Chenopodium quinoa Willd.) Grown in Washington State.

Quinoa (Chenopodium quinoa Willd) contains 2 to 5% saponins in the form of oleanane-type triterpenoid glycosides or sapogenins found in the external layers of the seeds. These saponins confer an undesirable bitter flavor. This study maps the content and profile of glycoside-free sapogenins from 22 quinoa varieties and 6 original breeding lines grown in North America under similar agronomical conditions. Saponins were recovered using a novel extraction protocol and quantified by GC-MS. Oleanolic acid (OA), hederagenin (HD), serjanic acid (SA), and phytolaccagenic acid (PA) were identified by their mass spectra. Total saponin content ranged from 3.81 to 27.1 mg/g among the varieties studied. The most predominant sapogenin was phytolaccagenic acid with 16.72 mg/g followed by hederagenin at 4.22 mg/g representing the ∼70% and 30% of the total sapogenin content. Phytolaccagenic acid and the total sapogenin content had a positive correlation of r2 = 0.88 (p < 0.05). Results showed that none of the varieties we studied can be classified as "sweet". Nine varieties were classified as "low-sapogenin". We recommend six of the varieties be subjected to saponin removal process before consumption. A multivariate analysis was conducted to evaluate and cluster the different genotypes according their sapogenin profile as a way of predicting the possible utility of separate quinoa in food products. The multivariate analysis showed no correlations between origin of seeds and saponin profile and/or content.