REVIEW: Aroma of Wheat Bread Crumb

Bread aroma is an important parameter for bread quality, and this review aims to provide an overview of aroma compounds identified in bread crumb and how these compounds are formed. More than 150 volatile compounds were identified in bread crumb, and they mainly originated from the fermentative activity of yeast, from oxidation of flour lipids, and to a lower extent from Maillard reactions. Of those volatile compounds, 45 compounds can be characterized as aroma compounds, because they most likely can be sensed when the bread is eaten because of their high odor activity values and flavor dilution factors. The influence of ingredients and mixing conditions on bread aroma has scarcely been investigated. The fermentation conditions (yeast level and strain as well as fermentation temperature and time) were found to significantly influence the aroma of bread crumb. Yeast level and strain mainly influence formation of compounds directly related to the fermentative activity of yeast, whereas fermentation temperature and time also influence formation of compounds from oxidation of flour lipids.     

Classification and characterization of manuka honeys based on phenolic compounds and methylglyoxal

Manuka honey from New Zealand is often considered to be a medicinal product of special value due to its high level of antimicrobial activity. Therefore, the distinct authentication of its botanical origin is of great importance. Aside from the common pollen analysis, it is in this respect particularly the analysis of the phenolic acids, flavonoids, and norisoprenoids that is described as useful. In the present study, numerous manuka honeys were analyzed by UPLC-PDA-MS/MS after solid-phase extraction and compared to other kinds of honey to define marker substances characteristic for manuka honeys. The PDA profiles obtained differed markedly from each other so that the individual honey samples could be assigned to three groups. For the honeys of group 1 the comparably high concentrations of 4-hydroxybenzoic acid, dehydrovomifoliol, and benzoic acid proved to be typical, whereas the profiles of group 2 showed high kojic acid and 2-methoxybenzoic acid intensities. The manuka honeys of group 3, on the other hand, yielded high amounts of syringic acid, 4-methoxyphenyllactic acid, and methyl syringate. Furthermore, the comprehensive comparison of manuka honeys to other unifloral honeys revealed that especially kojic acid, 5-methyl-3-furancarboxylic acid, leptosin, unedone, 2-methoxybenzoic acid, 4-methoxyphenyllactic acid, 3-hydroxy-1-(2-methoxyphenyl)penta-1,4-dione, and methyl syringate were useful for distinguishing manuka honeys from the other kinds of investigated honeys. Moreover, kojic acid, unedone, 5-methyl-3-furancarboxylic acid, 3-hydroxy-1-(2-methoxyphenyl)penta-1,4-dione, and lumichrome were identified in manuka honey for the first time.     

Inhibition of hepatitis B virus replication by drug-induced depletion of nucleocapsids

Chronic hepatitis B virus (HBV) infection is a major cause of liver disease. Only interferon-alpha and the nucleosidic inhibitors of the viral polymerase, 3TC and adefovir, are approved for therapy. However, these therapies are limited by the side effects of interferon and the substantial resistance of the virus to nucleosidic inhibitors. Potent new antiviral compounds suitable for monotherapy or combination therapy are highly desired. We describe non-nucleosidic inhibitors of HBV nucleocapsid maturation that possess in vitro and in vivo antiviral activity. These inhibitors have potential for future therapeutic regimens to combat chronic HBV infection.     

Distributions of microbial activities in deep subseafloor sediments

Diverse microbial communities and numerous energy-yielding activities occur in deeply buried sediments of the eastern Pacific Ocean. Distributions of metabolic activities often deviate from the standard model. Rates of activities, cell concentrations, and populations of cultured bacteria vary consistently from one subseafloor environment to another. Net rates of major activities principally rely on electron acceptors and electron donors from the photosynthetic surface world. At open-ocean sites, nitrate and oxygen are supplied to the deepest sedimentary communities through the underlying basaltic aquifer. In turn, these sedimentary communities may supply dissolved electron donors and nutrients to the underlying crustal biosphere.     

Structure of Rab GDP-dissociation inhibitor in complex with prenylated YPT1 GTPase

Rab/Ypt guanosine triphosphatases (GTPases) represent a family of key membrane traffic regulators in eukaryotic cells whose function is governed by the guanosine diphosphate (GDP) dissociation inhibitor (RabGDI). Using a combination of chemical synthesis and protein engineering, we generated and crystallized the monoprenylated Ypt1:RabGDI complex. The structure of the complex was solved to 1.5 angstrom resolution and provides a structural basis for the ability of RabGDI to inhibit the release of nucleotide by Rab proteins. Isoprenoid binding requires a conformational change that opens a cavity in the hydrophobic core of its domain II. Analysis of the structure provides a molecular basis for understanding a RabGDI mutant that causes mental retardation in humans.     

Characteristics of misreporters of dietary intake and physical activity

OBJECTIVE: To characterise misreporters of energy intake (EI) and energy expenditure (EE). DESIGN: Cross-sectional study, using a validated position and motion instrument, ActiReg, as the reference method to study misreporters of EI and of EE. EI was measured using a dietary record and EE using a physical activity questionnaire (PAQ). Misreporters were defined as subjects outside the 95% confidence limits of agreement between EI or EE reported/EE measured. SETTING: Free-living Danish volunteers. SUBJECTS: One hundred and thirty-eight volunteers aged between 20 and 59 years. RESULTS: Body mass index, smoking, 'try to eat healthily' and worries about weight were related to degree of under-reported EI. The percentage energy from added sugar was lowest (P < 0.001) and the percentage energy from protein (P < 0.001) highest in under-reporters compared with acceptable reporters. Subjects who reported being very physically active at work or in leisure time reported a higher EE than measured EE compared with less physically active subjects (P < 0.05). Likewise, subjects who regard themselves as fit or very fit reported a higher EE than subjects who regard themselves as moderately fit (P < 0.05). Possible over-reporters reported less time as very light activity (P = 0.007), more time as moderate activity (P = 0.01) and more time as vigorous activity (P = 0.02) than acceptable reporters. CONCLUSIONS: Under-reporting of EI should always be taken into consideration; however, only a few characteristics of under-reporters are consistent among studies. Misreporting of EI was more prevalent than misreporting of EE. The level of physical activity more than the time spent involved in various activities was misreported.     

由沙棘果实中类胡萝卜素-脂蛋白化合物研制新型化妆产品

沙棘果、种子和叶片中的大量营养和药用价值已经被长篇累牍地报道。众所周知的源自沙棘果实的沙棘油,目前被利用作为护肤品中的一种抗氧化剂和防紫外线成分或食品增补剂。