Formation and Degradation of Beta-casomorphins in Dairy Processing

Milk proteins including casein are sources of peptides with bioactivity. One of these peptides is beta-casomorphin (BCM) which belongs to a group of opioid peptides formed from b-casein variants. Beta-casomorphin 7 (BCM7) has been demonstrated to be enzymatically released from the A1 or B b-casein variant. Epidemiological evidence suggests the peptide BCM 7 is a risk factor for development of human diseases, including increased risk of type 1 diabetes and cardiovascular diseases but this has not been thoroughly substantiated by research studies. High performance liquid chromatography coupled to UV-Vis and mass spectrometry detection as well as enzyme–linked immunosorbent assay (ELISA) has been used to analyze BCMs in dairy products. BCMs have been detected in raw cow’s milk and human milk and a variety of commercial cheeses, but their presence has yet to be confirmed in commercial yoghurts. The finding that BCMs are present in cheese suggests they could also form in yoghurt, but be degraded during yoghurt processing. Whether BCMs do form in yoghurt and the amount of BCM forming or degrading at different processing steps needs further investigation and possibly will depend on the heat treatment and fermentation process used, but it remains an intriguing unknown

Fluorescence correlation spectroscopy of the binding of nucleotide excision repair protein XPC-hHr23B with DNA substrates

The interaction of the nucleotide excision repair (NER) protein dimeric complex XPC-hHR23B, which is implicated in the DNA damage recognition step, with three Cy3.5 labeled 90-bp double-stranded DNA substrates (unmodified, with a central unpaired region, and cholesterol modified) and a 90-mer single-strand DNA was investigated in solution by fluorescence correlation spectroscopy. Autocorrelation functions obtained in the presence of an excess of protein show larger diffusion times (τ d) than for free DNA, indicating the presence of DNA-protein bound complexes. The fraction of DNA bound (θ), as a way to describe the percentage of protein bound to DNA, was directly estimated from FCS data. A significantly stronger binding capability for the cholesterol modified substrate (78% DNA bound) than for other double-stranded DNA substrates was observed, while the lowest affinity was found for the single-stranded DNA (27%). This is in accordance with a damage recognition role of the XPC protein. The similar affinity of XPC for undamaged and 'bubble' DNA sub

The relationship between breakfast caloric intake and late morning blood glucose levels and cognitive capacities in a population of students

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Dye-substrate interactions evidenced by fluorescence correlation spectroscopy

In this report, we discuss how the nature of the substrate-water interaction may modify the free diffusion of single molecules, then influencing fluorescence correlation spectroscopy measurements. Our results show a strong influence, up to a few micrometers from the interface, of the surface polarity. This effect is assessed through the relative weight of the two dimension diffusion process observed close to the surface

Molécule unique, nanotube de carbone et exaltation Raman

La spectroscopie Raman fournit une analyse détaillée de la structure chimique d'un objet, à température ambiante. La section efficace de diffusion Raman d'un objet petit est souvent faible et son signal ne pourra être détecté sans utiliser un processus d'exaltation efficace de la diffusion. Cet article décrit quelques avancées dans le domaine de l'exaltation de surface de la diffusion Raman. Il est illustré par des résultats expérimentaux que nous avons obtenus sur des molécules uniques. Parfois, le signal de certains objets petits peut être détecté sans effet d'exaltation supplémentaire, comme le montre l'exemple de nanotubes remplis, dits peapods

Signal Raman de molécules uniques en présence d'agrégats d'argent structurés

Un nouveau type d'agrégats d'argent, dit “à facettes” a été utilisé comme substrat SERS. Nous avons analysé le signal Raman diffusé par ces agrégats individuellement en présence d'EDTA par microscopie confocale. En certains points, les spectres acquis présentent les caractéristiques de ceux attendus pour des molécules uniques. Cette étude est couplée avec une caractérisation en microscopie électronique (MEB et TEM). Nous avons ainsi établi une corrélation entre la présence d'exaltation et la morphologie des agrégats. De premiers résultats suggèrent la présence d'argent non réduit sur ces points chauds

Mise en évidence d’une carence iodée dans le Cirque de Salazie (Ile de la Réunion): Analyse de ses causes nutritionnelles et étude de ses conséquences

Randomized subjects (n = 294), (35 young children, 6-30 months old - 91 children 8.6 ± 0.7years, 116 teenagers 13.2 ± 1.9y - 52 young women 28.5 ± 6.1 y) leaving in a mountainous area of Reunion Island (Cirque de Salazie) were evaluated according to the following :a questionnaire related to food intake, cervical palpation for thyroid size evaluation and collections of urine and foods (natural and mineral water, breast and commercial milk and salt) for iodine measurement. Neonatal TSH of 308 new borns in Salazie were compared to TSH of 300 new-borns of Lille (France). The prevalence of goiter increases with age (0% in young children, 12.1% in children, 23.3% in teenagers, 38.4% in women) whereas median urinary iodine (μg/dl) decreases in the same groups (12-7.8-5.6-4.2). The intake of milk and dairy products significantly decreases from children to adults. Neonatal TSH values are significantly higher in Salazie than in Lille (p < 0.005). Natural and mineral water, breast milk and salt contain little iodine. In conclusion iodine deficiency is present in this area of Reunion Island with a significant increment of neonatal TSH values.SCOPUS: ar.jinfo:eu-repo/semantics/publishe