Semi-industrial production of a minimally processed infant formula powder using membrane filtration.

Infant formula (IF) is submitted to several heat treatments during production, which can lead to denaturation or aggregation of proteins and promote Maillard reaction. The objective of this study was to investigate innovative minimal processing routes for the production of first-age IF powder, thus ensuring microbial safety with minimal level of protein denaturation. Three nutritionally complete IF powders were produced at a semi-industrial scale based on ingredients obtained by fresh bovine milk microfiltration (0.8 and 0.1-µm pore size membranes). Low-temperature vacuum evaporation (50°C) and spray-drying (inlet and outlet temperatures of 160 and 70°C, respectively) were conducted to produce the T- formula with no additional heat treatment. The T+ formula was produced with a moderate heat treatment (75°C for 2 min) applied before spray-drying, whereas the T+++ formula received successive heat treatments (72°C for 30 s on the milk; 90°C for 2-3 s before evaporation; 85°C for 2 min before spray-drying), thus mimicking commercial powdered IF. Protein denaturation and Maillard reaction products were followed throughout the production steps and the physicochemical properties of the powders were characterized. The 3 IF powders presented satisfactory physical properties in terms of aw, free fat content, glass transition temperature, and solubility index, as well as satisfactory bacteriological quality with a total flora <103 cfu/g and an absence of pathogens when a high level of bacteriological quality of the ingredients was ensured. Protein denaturation occurred mostly during the heat treatments of T+ and T+++ and was limited during the spray-drying process. The IF powder produced without heat treatment (T-) presented a protein denaturation extent (6 ± 4%) significantly lower than that in T+++ (58 ± 0%), but not significantly different from that in T+ (10 ± 4%). Although T- tended to contain less Maillard reaction products than T+ and T+++, the Maillard reaction products did not significantly discriminate the infant formulas in the frame of this work. The present study demonstrated the feasibility of producing at a semi-industrial scale an infant formula being bacteriologically safe and containing a high content of native proteins. Application of a moderate heat treatment before spray-drying could further guarantee the microbiological quality of the IF powders while maintaining a low protein denaturation extent. This study opens up new avenues for the production of minimally processed IF powders.

Structural snapshots of the rearrangement of the bis(di-tert-butyl-aminophenyl)amine pincer ligand in the presence of transition metal ions.

The bis(di-tert-butyl-aminophenyl)amine ligand H3LN,N,N was reacted with Mn(ii), Co(ii), Fe(iii) and Cu(ii) salts in air. The ligand undergoes oxidative transformations, which involve intra and intermolecular C-N and N-N bond formations. A rare aromatic C-N bond cleavage leading to a C-O bond has also been observed.

Tritium levels in milk in the vicinity of chronic tritium releases.

Tritium is the radioactive isotope of hydrogen. It can be integrated into most biological molecules. Even though its radiotoxicity is weak, the effects of tritium can be increased following concentration in critical compartments of living organisms. For a better understanding of tritium circulation in the environment and to highlight transfer constants between compartments, we studied the tritiation of different agricultural matrices chronically exposed to tritium. Milk is one of the most frequently monitored foodstuffs in the vicinity of points known for chronic release of radionuclides firstly because dairy products find their way into most homes but also because it integrates deposition over large areas at a local scale. It is a food which contains all the main nutrients, especially proteins, carbohydrates and lipids. We thus studied the tritium levels of milk in chronic exposure conditions by comparing the tritiation of the main hydrogenated components of milk, first, component by component, then, sample by sample. Significant correlations were found between the specific activities of drinking water and free water of milk as well as between the tritium levels of cattle feed dry matter and of the main organic components of milk. Our findings stress the importance of the metabolism on the distribution of tritium in the different compartments. Overall, dilution of hydrogen in the environmental compartments was found to play an important role dimming possible isotopic effects even in a food chain chronically exposed to tritium.

[Beckwith-Wiedemann syndrome: What do you search in prenatal diagnosis? About 14 cases]. / Le syndrome de Beckwith-Wiedemann : que faut-il rechercher en anténatal? À propos d'une série de 14 cas.

OBJECTIVES: Beckwith-Wiedemann syndrome (BWS) is the most common overgrowth syndrome and has an incidence of 1/13,700. The majority of the cases are diagnosed after birth. Patients with BWS have an increased risk of neonatal hypoglycemia and embryonal tumors development in childhood. We wanted to identify the ultrasound signs that must alert physicians to prepare best perinatal management strategies. METHODS: We conducted a retrospective study of a population of 14 cases of BWS diagnosed in perinatal period; four of them were detected prenatally by ultrasound. The anomalies signs described in prenatal were analyzed and compared with the clinical features of the postnatal period. RESULTS: The major features reported were represented by macrosomia for 71.4% with an increase of abdominal circumference, and macroglossia for 78.6%. The minor features were various with 64% of visceromegaly (nephromegaly and/or hepatomegaly), 50% of hydramnios and for 80% of male children a genital anomaly (crytorchidism and/or hypospadias). CONCLUSION: This study identified some prenatal ultrasound signs that should alert the clinician to the possibility of BWS. A genetic conseling, after confirmation by molecular diagnosis, could be proposed in a near future in prenatal, and could improve postnatal management strategies for these affected children at high postnatal risk.

Unprecedented redox-driven ligand ejection in nickel(II)-diiminosemiquinonate radical complexes.

Nickel(II) complexes of (M : L) stoichiometries 1 : 1 (1) and 1 : 2 (2) were prepared from a polydentate ligand involving diiminosemiquinonate radicals. Both were characterized by X-ray diffraction, Vis-NIR and EPR spectroscopy as well as electrochemistry. Ligand-centered oxidation of 1 promotes ligand ejection to give 2.

Microfiltration of raw whole milk to select fractions with different fat globule size distributions: process optimization and analysis.

We present an extensive description and analysis of a microfiltration process patented in our laboratory to separate different fractions of the initial milk fat globule population according to the size of the native milk fat globules (MFG). We used nominal membrane pore sizes of 2 to 12 microm and a specially designed pilot rig. Using this process with whole milk [whose MFG have a volume mean diameter (d43) = 4.2 +/- 0.2 microm] and appropriate membrane pore size and hydrodynamic conditions, we collected 2 extremes of the initial milk fat globule distribution consisting of 1) a retentate containing large MFG of d43 = 5 to 7.5 microm (with up to 250 g/kg of fat, up to 35% of initial milk fat, and up to 10% of initial milk volume), and 2) a permeate containing small MFG of d43 = 0.9 to 3.3 microm (with up to 16 g/kg of fat, up to 30% of initial milk fat, and up to 83% of initial milk volume and devoid of somatic cells). We checked that the process did not mechanically damage the MFG by measuring their zeta-potential. This new microfiltration process, avoiding milk aging, appears to be more efficient than gravity separation in selecting native MFG of different sizes. As we summarize from previous and new results showing that the physico-chemical and technological properties of native milk fat globules vary according to their size, the use of different fat globule fractions appears to be advantageous regarding the quality of cheeses and can lead to new dairy products with adapted properties (sensory, functional, and perhaps nutritional).

Determination of taste-active compounds of a bitter Camembert cheese by omission tests.

The taste-active compounds of a Camembert cheese selected for its intense bitterness defect were investigated. The water-soluble fraction (WSE) was extracted with pure water and fractionated by successive tangential ultrafiltrations and nanofiltration. The physicochemical assessment of these fractions led to the construction of a model WSE which was compared by sensory evaluation to the crude water-soluble extract, using a panel of 16 trained tasters. As no significant difference was perceived, this model WSE was then used directly or mixed with other cheese components for omission tests. Among the main taste characteristics of the WSE (salty, sour, umami and bitter), bitterness was found to be due to small peptides whose mass distribution was obtained by RPHPLC-MS (400-3000 Da) and whose taste properties are discussed.