Microcapsules Consisting of Whey Proteins-Coated Droplets of Lipids Embedded in Wall Matrices of Spray-Dried Microcapsules Consisting Mainly of Non-Fat Milk Solids.

The effects of wall composition and heat treatment on the formation and properties of core-in-wall emulsions (CIWEs) consisting of whey protein-coated milkfat (AMF) droplets and a dispersion of non-fat milk solids (MSNF) were investigated. Microcapsules were prepared by spray drying these CIWEs. The d3.2 of the CIWEs ranged from 0.36 to 0.54 µm. Surface excess of the CIWEs ranged from 1.39 to 6.57 mg/m2, and was influenced by concentration of whey proteins and heat treatment (30 min at 90 °C). Results indicated a preferential adsorption of ß-lg at the O/W interface. Whey proteins accounted for up to 90% of the proteins adsorbed at the O/W interface. The core retention during spray drying ranged from 90.3% to 97.6% and microencapsulation efficiency ranged from 77.9% to 93.3%. The microcapsules exhibited an excellent long-term oxidative stability at 20 and 30 °C that was superior to that of microcapsules consisting of milkfat and MSNF, where the O/W interface was populated mainly by caseins. The superior oxidative stability could be attributed to the formation of dense whey-proteins-based films at the O/W interfaces of the CIWEs that isolated the core domains from the environment. The results open new opportunities in developing highly stable lipids-containing microcapsules and dairy powders.

A model biorefinery for avocado (Persea americana mill.) processing.

This research investigated and evaluated a biorefinery for processing avocado Hass variety into microencapsulated phenolic compounds extract, ethanol, oil and xylitol. Avocado was first characterized for its potential valuable compounds; then, the techno-economic and environmental aspects of the biorefinery were developed and finally the total production costs and potential environmental impact of the proposed biorefinery were investigated. Four scenarios of the biorefinery were evaluated with different extent of mass and energy integration as well as the incorporation of a cogeneration system. Results indicated that the main fatty acid in the pulp of the investigated avocado variety was oleic acid (50.96%) and that this fruit contained significant amount of holocellulose (52.88% and 54.36% in the peel and seed, respectively). Techno-economic and environmental assessment suggested an attractive opportunity for a biorefinery for complete utilization of the avocado fruit as well the importance of the level of integration.

A biorefinery for efficient processing and utilization of spent pulp of Colombian Andes Berry (Rubus glaucus Benth.): Experimental, techno-economic and environmental assessment.

This work investigated a model biorefinery for producing phenolic compounds extract, ethanol and xylitol from spent blackberry pulp (SBP). The biorefinery was investigated according to four potential scenarios including mass and heat integrations as well as cogeneration system for supplying part of the energy requirements in the biorefinery. The investigated SBP had 61.54% holocellulose; its total phenolic compounds was equivalent to 2700mg of gallic acid/100g SBP, its anthocyanins content was 126.41mg/kg of SBP and its total antioxidant activity was 174.8µmol TE/g of SBP. The economic analysis revealed that the level of integration in the biorefinery significantly affected the total production cost. The sale-to-total-production-cost ratio indicated that both, mass and heat integrations are of importance relevance. The cost of supplies (enzymes and reagents) had the most significant impact on the total production cost and accounted between 46.72 and 58.95% of the total cost of the biorefinery.

The diagnostic value of first-voided urinary LH compared with GNRH-stimulated gonadotropins in differentiating slowly progressive from rapidly progressive precocious puberty in girls.

OBJECTIVE: Characterization of pubertal progression is required to prevent unnecessary intervention in unsustained or slowly progressive (SP) precocious puberty (PP), while delivering hormonal suppression in rapidly progressive (RP) PP. We aimed to assess the diagnostic value of first-voided urinary LH (ULH) compared with GNRH-stimulated gonadotropins in differentiating these forms of PP. METHODS: A total of 62 girls with PP underwent both GNRH stimulation and ULH assay. Fifteen girls with peak LH ≥ 10 IU/L started treatment immediately, whereas the other 47 girls were evaluated after 6 months for pubertal advancement, height acceleration, and bone-age maturation. Based on these criteria, the participants were assigned to five subgroups: pubertal regression, no progression or progression by one, two or three criteria. The first three subgroups were defined as SP-PP (n=29), while the other two subgroups were defined as RP-PP (n=18). An additional 23 prepubertal girls were evaluated for ULH. RESULTS: ULH but not serum gonadotropins could distinguish girls with two and three criteria from less progressive subgroups. By comparison with SP-PP (i.e. regression group and groups 0 and 1), those with RP-PP (group 2+3) had lower peak FSH (9.28±2.51 vs 12.57±4.30; P=0.007) and higher peak LH:FSH ratio (0.42±0.30 vs 0.22±0.12; P=0.022) and ULH (1.63±0.65 vs 1.05±0.26 IU/l; P<0.001). Based on receiver operating characteristics analysis, a ULH cutoff of 1.16 IU/l had a better sensitivity (83%) and positive and negative predictive values (65 and 88% respectively) than the other two parameters, with a specificity of 72%. CONCLUSIONS: ULH assay is a noninvasive, reliable method that can assist in the distinction between SP- and RP-PP.

Cold-set whey protein microgels containing immobilised lipid phases to modulate matrix digestion and release of a water-soluble bioactive.

This study investigated the in-vitro digestibility of cold-set whey protein (WP) microgels prepared by two gelation methods (external and internal) containing lipids (0%, 10% or 20% w/w). The incorporation of lipids into these matrices achieved higher entrapment of the bioactive vitamin riboflavin, as well as significant reductions in rates of both the digestion of the protein matrix, and the subsequent diffusion of the water-soluble bioactive. A biexponential model accounted for the contribution of digestion- and diffusion-driven mechanisms in describing the release of riboflavin into enzyme containing simulated gastrointestinal fluids. In particular, for external gelation microgels, as the lipid load within the matrices increased, the contribution of a faster diffusion-driven release was almost completely negated by a slower digestion-assisted release. Lipid loads provided a composite matrix capable of alternating from a burst to a sustained release of bioactive.

Uptake of divalent ions (Mn+2 and Ca+2) by heat-set whey protein gels.

UNLABELLED: Divalent salts are used commonly for gelation of polymer molecules. Calcium, Ca(+2), is one of the most common divalent ions that is used in whey protein gels. Manganese, Mn(+2), is also divalent, but paramagnetic, enhancing relaxation decay rates in magnetic resonance imaging (MRI) and can be used as a probe to understand the behavior of Ca(+2) in whey protein gels. The objective of this study was to investigate the diffusion of Ca(+2) and Mn(+2) ions in heat-set whey protein gels by using MRI and nuclear magnetic resonance (NMR) relaxometry. Whey protein gels were immersed in solutions containing MnCl(2) and CaCl(2) at neutral pH. Images obtained with gels immersed in MnCl(2) solution revealed a relaxation sink region in the gel's surface and the thickness of the region increased with time. These "no signal" regions in the MR images were attributed to uptake of Mn(+2) by the gel. Results obtained with CaCl(2) solution indicated that since Ca(+2) did not have the paramagnetic effect, the regions where Ca(+2) diffused into the gel exhibited a slight decrease in signal intensity. The relaxation spectrums exhibited 3 populations of protons, for gels immersed in MnCl(2) solution, and 2 populations for gels in CaCl(2) solution. No significant change in T(2) distributions was observed for the gels immersed in CaCl(2) solution. The results demonstrated that MRI and NMR relaxometry can be used to understand the diffusion of ions into the whey protein gel, which is useful for designing gels of different physical properties for controlled release applications. PRACTICAL APPLICATION: Design of food systems for delivery of bioactive compounds requires knowledge of diffusion rates and structure. Utilizing magnetic resonance imaging the diffusion rates of ions can be measured. Relaxation spectra could yield information concerning molecular interactions.

Magnetic resonance imaging (MRI) and relaxation spectrum analysis as methods to investigate swelling in whey protein gels.

Effective means for controlled delivery of nutrients and nutraceuticals are needed. Whey protein-based gels, as a model system and as a potential delivery system, exhibit pH-dependent swelling when placed in aqueous solutions. Understanding the physics that govern gel swelling is thus important when designing gel-based delivery platforms. The extent of swelling over time was monitored gravimetrically. In addition to gravimetric measurements, magnetic resonance imaging (MRI) a real-time noninvasive imaging technique that quantified changes in geometry and water content of these gels was utilized. Heat-set whey protein gels were prepared at pH 7 and swelling was monitored in aqueous solutions with pH values of 2.5, 7, and 10. Changes in dimension over time, as characterized by the number of voxels in an image, were correlated to gravimetric measurements. Excellent correlations between mass uptake and volume change (R(2)= 0.99) were obtained for the gels in aqueous solutions at pH 7 and 10, but not for gels in the aqueous solution at pH 2.5. To provide insight into the mechanisms for water uptake, nuclear magnetic resonance (NMR) relaxation times were measured in independent experiments. The relaxation spectrum for the spin-spin relaxation time (T(2)) showed the presence of 3 proton pools for pH 7 and 10 trials and 4 proton pools for pH 2.5 trials. Results demonstrate that MRI and NMR relaxation measurements provided information about swelling in whey protein gels that can constitute a new means for investigating and developing effective delivery systems for foods.

Micellization of bovine beta-casein studied by isothermal titration microcalorimetry and cryogenic transmission electron microscopy.

The association behavior, critical micellization concentration (CMC), and enthalpy of demicellization (DeltaHdemic) of bovine beta-casein were studied, for the first time by isothermal titration calorimetry, in a pH 7.0 phosphate buffer with 0.1 ionic strength and in pure water. In the buffer solutions, the CMC decreased asymptotically from 0.15 to 0.006 mM as the temperature was raised from 16 to 45 degrees C. DeltaHdemic decreased with increasing temperature between 16 and 28 degrees C but increased from 28 to 45 degrees C. Thermodynamic analysis below 30 degrees C is consistent with the Kegeles shell model, which suggests a stepwise association process. At higher temperatures, this model exhibits limitations, and the micellization becomes much more cooperative. The CMC values in water, measured between 17 and 28 degrees C, decreased with increasing temperature and, expectedly, were higher than those found in the buffer solutions. beta-Casein micelles were visualized and characterized, for the first time in their hydrated state, using advanced digital-imaging cryogenic transmission electron microscopy. The images revealed small, oblate micelles, about approximately 13 nm in diameter. The micelles shape and dimensions remained nearly constant in the temperature range of 24-35 degrees C.

Ensayo educacional de modificación de los hábitos dentales en niños de edad preescolar / An educational essay of dental habits modification in preschool children

Se realizó un estudio en 32 jardines de infantes de Beersheba, Israel, comparando la eficacia de 4 abordajes educacionales diferentes en material de salud bucal. Si bien los resultados no demostraron diferencias estadísticamente significativas entre los 4 métodos educacionales, el cepillado dental de los niños mejoró notoriamente, así como los hábitos alimentarios y la concurrencia al odontólogo

Ensayo educacional de modificación de los hábitos dentales en niños de edad preescolar / An educational essay of dental habits modification in preschool children

Se realizó un estudio en 32 jardines de infantes de Beersheba, Israel, comparando la eficacia de 4 abordajes educacionales diferentes en material de salud bucal. Si bien los resultados no demostraron diferencias estadísticamente significativas entre los 4 métodos educacionales, el cepillado dental de los niños mejoró notoriamente, así como los hábitos alimentarios y la concurrencia al odontólogo (AU)