Sensomics-Assisted Aroma Decoding of Pea Protein Isolates (Pisum sativum L.).

The aroma of pea protein (Pisum sativum L.) was decrypted for knowledge-based flavor optimization of new food products containing pea protein. Sensomics helped to determine several volatiles via ultra-high performance liquid chromatography tandem mass spectrometry and 3-nitrophenylhydrazine derivatization. Among the investigated volatiles, representatives of aldehydes, ketones, and acids were reported in literature as especially important in pea and pea-related matrices. After validation of the method and quantitation of the corresponding analytes, sensory reconstitution as well as omission studies of a selected pea protein were performed and revealed nine odor-active compounds as key food odorants (3-methylbutanal, hexanal, acetaldehyde, (E,E)-2,4-nonadienal, (E)-2-octenal, benzaldehyde, heptanal, 2-methylbutanal, and nonanoic acid). Interestingly, eight out of nine compounds belonged to the chemical class of aldehydes. Statistical heatmap and cluster analysis of all odor activity values of different pea proteins confirmed the obtained sensory results and generalize these nine key food odorants in other pea proteins. The knowledge of key components gained shows potential for simplifying industrial flavor optimization of pea protein-based food.

Sensomics-Assisted Flavor Decoding of Dairy Model Systems and Flavor Reconstitution Experiments.

The whole sensometabolome of a typical dairy milk dessert was decoded to potentially serve as a blueprint for further flavor optimization steps of functional fat-reduced food. By applying the sensomics approach, a wide range of different dairy volatiles, semi and nonvolatiles, were analyzed by ultrahigh-performance liquid chromatography tandem mass spectrometry with or without derivatization presteps. While for volatile sulfur compounds with low odor thresholds, headspace solid-phase microextraction gas chromatography was established, abundant carbohydrates and organic acids were quantified by quantitative 1H nuclear magnetic resonance spectroscopy. Validated quantitation, sensory reconstitution, and omission studies highlighted eight flavor-active compounds, namely, diacetyl, δ-tetra-, δ-hexa-, and δ-octadecalactone, sucrose, galactose, lactic acid, and citric acid as indispensable for flavor recombination. Furthermore, eight odorants (acetaldehyde, acetic acid, butyric acid, methanethiol, phenylacetic acid, dimethyl sulfide, acetoin, and hexanoic acid), all with odor activity values >1, additionally contributed to the overall flavor blueprint. Within this work, a dairy flavor analytical toolbox covering four different high-throughput methods could successfully be established showing potential for industrial applications.

Factors contributing to the risk of cardiovascular disease reflected by plasma adiponectin: data from the coronary risk factors for atherosclerosis in women (CORA) study.

OBJECTIVE: An inverse association of adiponectin with coronary heart disease (CHD) has been reported, but the results are inconsistent. We used data from the CORA study to investigate into plasma concentrations of adiponectin and factors that may mediate the link to incident CHD. DESIGN: The CORA study is a population-based case-control study on 200 women with incident CHD and 255 age-matched controls. RESULTS: Plasma concentrations of adiponectin were significantly lower in women with CHD (p<0.0001), and in women with BMI >or=25 kg/m(2) (p<0.02), even more so with central obesity (WHR >or=0.85), prevalent diabetes or insulin resistance (HOMA-IR >or=3.8), or low HDL-cholesterol (<50mg/dl), and in smokers (each p<0.0001). Adiponectin also correlated with intake of fruit and vegetables, meat and sausage and alcohol as dietary markers of cardiovascular risk. Strikingly, the trend towards lower adiponectin concentrations with increasing BMI or waist circumference was less marked than the difference of adiponectin between CHD cases and controls. In a logistic regression model the odds ratio of adiponectin of 0.943 per 1 microg/ml (CI 0.919-0.968, p<0.0001) for risk of CHD was progressively reduced by elevated WHR, obesity-related risk factors, smoking, and dietary parameters. CONCLUSIONS: Plasma adiponectin indicates protection from CHD in women that is attenuated by combined effects of central obesity and dependent risk factors, parameters of nutrition and smoking. Thus, the impact of adiponectin goes beyond its relation to central adiposity, but may also reflect independent effects of lifestyle.

Systematic mutagenesis of potential glycosylation sites of lysosomal acid lipase.

Lysosomal acid lipase (LAL; EC 3.1.1.13) is a key enzyme in the intracellular lipid metabolism. It hydrolyzes exogenous triglycerides and cholesterol esters taken up by various cell types. LAL has six potential N-glycosylation sites and one potential O-glycosylation site. Elimination of each of the six Asn-(X)-Ser/Thr sites by site-directed mutagenesis and expression in baculovirus-infected Spodoptera frugiperda cells resulted in two single-mutant enzymes without lipolytic activities (N134Q and N246Q) and four mutants with preserved activities. The two inactive mutants were not detectable on immunoblot analysis, indicating that they were not secreted. Six double mutants in all possible combinations except for the two inactive single mutants were produced and expressed. Double mutants in combination with the N9 glycosylation site showed reduced activities as compared to the other mutants or the wild-type enzyme. Kinetic data of LAL glycosylation mutants indicate that substrate affinity of N9Q was not changed, but k (cat) of N9 mutants was reduced distinctly compared to the wild-type enzyme. Peanut agglutinin lectin did not recognize LAL, demonstrating that the protein has no core1 structure (Galbeta 1-3 GalNAc) of O-glycosylation. These data indicate that at least two of the six N-glycosylation sites are used in native lipase. N134 and N246 were found to be essential for LAL activity. We conclude that glycosylation plays an important role in the formation of functional LAL.