Comprehensive Analyses of Carbohydrates, 1,2-Dicarbonyl Compounds, and Advanced Glycation End Products in Industrial Bread Making.

The technology of bread making is characterized by three major steps: dough mixing, proofing, and baking. To follow the course of Maillard processes in an authentic food matrix, the complete manufacturing process of wheat bread rolls was assessed along all production steps with the quantitation of sugars, furfurals, 1,2-dicarbonyl compounds, and advanced glycation end products (AGEs). As a result, the AGE profile was significantly enlarged to more than 12 structures, and comprehensive mechanistic insights were provided. The analyses of five major German bread types including wheat, brown, rye bread, pumpernickel, and crispbreads led to AGE contents of 69-149 mg/kg bread or 984-1857 mg/kg protein. Major lysine protein modifications were carboxymethyl, carboxyethyl, and formyl lysine and pyrraline. Arginine was mainly modified by methylglyoxal (MGO) to give imidazolinones. A major part of MGO was confirmed to stem from microbial metabolism.

Influence of ß-Carotene and Lycopene on Oxidation of Ethyl Linoleate in One- and Disperse-Phased Model Systems.

The induction period (IP) of ethyl linoleate stressed at 60 °C was monitored via the formation of hydroperoxides. The addition of lycopene (1% w/w) increased the IP from 7.0 to 10.0 h to prove the strong antioxidative potential in contrast to ß-carotene with pro-oxidative effects (IP: 6.0 h), both showing strong scavenging activity under fast degradation. When peroxidation was induced by singlet oxygen, both carotenoids effectively inhibited the formation of hydroperoxides, with quenching activity only observed at low singlet oxygen concentrations, while scavenging still dominated. Thus, carotenoids did not interact with the introduced singlet oxygen but rather with the radical intermediates of fat oxidation. These experiments were then transferred to lecithin-based micelles more related to biological systems, where singlet oxygen was generated in the outer aqueous phase. Lycopene and ß-carotene delayed or inhibited lipid peroxidation depending on concentration. In this setup, ß-carotene showed exclusively quenching activity, while lycopene was additionally degraded to about 70%.

Oxidative Fragmentation of Aspalathin Leads to the Formation of Dihydrocaffeic Acid and the Related Lysine Amide Adduct.

In the present study, the degradation of C-glucosidic dihydrochalcone aspalathin as the major phenolic compound in rooibos (Aspalathus linearis) was investigated. Analyses by gas chromatography-mass spectrometry of aqueous aspalathin-lysine incubations after silylation showed the formation of dihydrocaffeic acid [3-(3,4-dihydroxyphenyl)-propionic acid] under oxidative conditions as a novel degradation product up to 10 mol %. High-performance liquid chromatography analyses revealed the concurrent formation of the dihydrocaffeic acid lysine amide at about 30-fold lower concentrations, which was unequivocally verified by synthesis of an authentic reference standard. The amide was also verified in aspalathin-protein incubations after enzymatic hydrolysis by high-performance liquid chromatography-tandem mass spectrometry analyses. Thus, the covalent interaction of phenolic plant compounds with proteins under mild conditions (ambient temperatures and neutral pH) was confirmed for the first time. Acid and free amide were also quantitated in rooibos teas with significantly higher values in fermented varieties. The mechanism of formation was clarified to be initiated by singlet oxygen and to include a rearrangement-fragmentation mechanism with 1,2,3,5-tetrahydroxybenzene as the counterpart.

Efficient Analysis of 2-Acetyl-1-pyrroline in Foods Using a Novel Derivatization Strategy and LC-MS/MS.

2-Acetyl-1-pyrroline (2-AP) is a key odorant in many foods, such as aromatic rice and wheat bread, with a very low odor threshold of 0.05 µg/L in water. The small molecule with a popcornlike, roasty odor is generated biologically or by Strecker degradation within the Maillard-reaction cascades during thermal food processing with methylglyoxal and 1-pyrroline as the main direct precursors. Numerous gas-chromatographic methods for the analysis of 2-AP have been published, but the reactivity of the compound leads to discrimination or degradation during sample workup. We developed a novel derivatization method for 2-AP with o-phenylenediamine followed by HPLC-MS/MS analysis of the resulting stable quinoxaline. The precision (7%), repeatability (14%), recovery (92%), linearity (0.79-500 µg/kg), limit of detection (LOD, 0.26 µg/kg), and limit of quantitation (LOQ, 0.79 µg/kg) were validated for rice matrix and were excellent as compared with those of methods published before. With the novel method, 2-AP levels in typical foods like aromatic rice (131 µg/kg), wheat bread (18 µg/kg), brown bread (18 µg/kg), rye bread (18 µg/kg), and popcorn (38 µg/kg) were determined.

Life after sepsis: an international survey of survivors to understand the post-sepsis syndrome.

OBJECTIVE: In this study, we aim to describe the post-sepsis syndrome from the perspective of the sepsis survivors. DESIGN AND SETTING: The study is a prospective, observational online international survey. PARTICIPANTS: Sepsis survivors enrolled via social media from 13 September 2014 to 13 September 2016. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Physiologic, physical and psychological function post-sepsis; and patient satisfaction with sepsis-centered care. RESULTS: 1731 completed surveys from 41 countries were analyzed, with 79.9% female respondents, age 47.6 ± 14.4 years. The majority of respondents (47.8%) had sepsis within the last year. Survivors reported an increase in sensory, integumentary, digestive, breathing, chest pain, kidney and musculoskeletal problems after sepsis (all P-value <0.0001). Physical functions such as daily chores, running errands, spelling, reading and reduced libido posed increased difficulty (all P-value <0.0001). Within 7 days prior to completing the survey, the survivors reported varying degrees of anxiety, depression, fatigue and sleep disturbance. Sepsis survivors reported dissatisfaction with a number of hospital support services, with up to 29.3% of respondents stating no social services support was provided for their condition. CONCLUSIONS: Sepsis survivors suffer from a myriad of physiologic, physical and psychological challenges. Survivors overall reveal dissatisfaction with sepsis-related care, suggesting areas for improvement both in-hospital and post-discharge.

Lycopene inhibits the isomerization of ß-carotene during quenching of singlet oxygen and free radicals.

The present study aimed to investigate the influence of singlet oxygen and radical species on the isomerization of carotenoids. On the one hand, lycopene and ß-carotene standards were incubated with 1,4-dimethylnaphthalene-1,4-endoperoxide that produced singlet oxygen in situ. (13Z)- and (15Z)-ß-carotene were preferentially generated at low concentrations of singlet oxygen, while high concentrations resulted in formation of (9Z)-ß-carotene. The addition of different concentrations of lycopene led to the same isomerization progress of ß-carotene, but resulted in a decreased formation of (9Z)-ß-carotene and retarded degradation of (all-E)-ß-carotene. On the other hand, isomerization of ß-carotene and lycopene was induced by ABTS-radicals, too. As expected from the literature, chemical quenching was observed especially for lycopene, while physical quenching was preferred for ß-carotene. Mixtures of ß-carotene and lycopene resulted in a different isomerization progress compared to the separate ß-carotene model. As long as lycopene was present, almost no isomerization of ß-carotene was triggered; after that, strong formation of (13Z)-, (9Z)-, and (15Z)-ß-carotene was initiated. In summary, lycopene protected ß-carotene against isomerization during reactions with singlet oxygen and radicals. These findings can explain the pattern of carotenoid isomers analyzed in fruits and vegetables, where lycopene containing samples showed higher (all-E)/(9Z)-ß-carotene ratios, and also in in vivo samples such as human blood plasma.

Growing and processing conditions lead to changes in the carotenoid profile of spinach.

This study aimed to evaluate the influence of different light regimens during spinach cultivation on the isomeric composition of ß-carotene. Irradiation with a halogen lamp, which has a wavelength spectrum close to that of daylight, was used to mimic field-grown conditions. The additional use of optical filters was established as a model system for greenhouse cultivation. Field-grown model systems led to a preferential increase of 9-cis-ß-carotene, whereas 13-cis-ß-carotene was just formed at the beginning of irradiation. Additionally 9,13-di-cis-ß-carotene decreased significantly in the presence of energy-rich light. Isomerization of ß-carotene was strongly suppressed during irradiation in greenhouse-grown model systems and led to significant differences. These results were verified in biological samples. Authentic field-grown spinach (Spinacia oleracea L.) showed among changes of other isomers a significantly higher level of 9-cis-isomers (7.52 ± 0.14%) and a significantly lower level of 9,13-di-cis-isomers (0.25 ± 0.03%) compared to authentic greenhouse-grown spinach (6.49 ± 0.11 and 0.76 ± 0.05%). Almost all analyzed commercial spinach samples (fresh and frozen) were identified as common field-grown cultivation. Further investigations resulted in a clear differentiation of frozen commercial samples from fresh spinach, caused by significantly higher levels of 13-cis- and 15-cis-ß-carotene as a result of industrial blanching processes.

Photoinduced isomerization of lycopene and application to tomato cultivation.

The present study aimed to investigate if growth conditions have an impact on the isomeric composition of lycopene in tomatoes. First a model system for photoinduced isomerization was established. Tomato extracts were irradiated with a halogen lamp, whose wavelength spectrum is close to the spectrum of daylight and thus mimics field-grown cultivation. Different optical filters were interposed between lamp and samples to simulate greenhouse conditions. 5-cis-Lycopene was formed preferentially while the concentration of 7-cis-lycopene decreased in field-grown model systems. The change of isomerization in greenhouse model systems led to a significantly different ratio. Consequently 5-cis- and 7-cis-lycopene were identified as potent markers for the differentiation of various lighting conditions during cultivation. This result was verified in biological samples. Authentic field-grown tomatoes (var. Lycopersicon esculentum Mill. var. commune L. H. Bailey "Harzfeuer") showed a significantly higher content of 5-cis-lycopene 5.90 ± 0.45% compared to tomatoes of the same variety grown under electric lighting 4.11 ± 0.10%. Additionally, the ratio of 7-cis-lycopene was significantly lower under field-grown conditions.