Inter-relationships between composition, physicochemical properties and functionality of lecithin ingredients

Background: Lecithin is widely used as an ingredient in the food industry due to its diverse functionality, mainly attributed to phospholipids (PL), the principal constituents. However, a systematic understanding of the functional properties of lecithin ingredients is missing in the literature. Scope and approach: This review outlines recent developments in lecithin from botanical origin and reviews the complex inter-relationships between physicochemical properties of PL in lecithin and selected techno-functional properties in micelles, liposomes and oil-in-water emulsions. Key findings and conclusions: Attributed to their polar phosphatide group and non-polar fatty acids, PL have specific molecular geometries, dissociation constants and charge, which strongly influence their functional properties in micelles, liposomes and oil-in-water emulsions. The PL profile and extrinsic factors (e.g., water, oil, hexane) influence the formation of micelles during separation of lecithin from oil using membrane filtration. In liposomes, PL profile and the presence of surface modifiers (i.e., sterols) affect the particle size and encapsulation efficiency. In emulsion systems, PL and their interaction with minerals and other functional ingredients (e.g., proteins), influence the particle size and physical stability of the oil droplets. This work provides an integrated review of the links between the composition and physicochemical properties of PL, and in turn, scientifically underpins the links between physicochemical and functional properties of lecithin

Influence of glycomacropeptide on rehydration characteristics of micellar casein concentrate powder

Glycomacropeptide (GMP) shows potential for enhancing the rehydration properties of high-protein dairy powders due to its hydrophilic nature. This study involved formulating micellar casein concentrate (MCC) solutions (8.6% final protein content) with 0, 10, and 20% GMP as a percentage of total protein, and investigated the physicochemical and rehydration properties of the resultant freeze-dried powders (P-MCC-0G, P-MCC-10G, and P-MCC-20G, respectively). The surface charges of caseins in the control MCC and 10 or 20% GMP blended solutions were −25.8, −29.6, and −31.5 mV, respectively. Tablets prepared from P-MCC-10G or P-MCC-20G powders displayed enhanced wettability with contact angle values of 80.6◦ and 79.5◦, respectively, compared with 85.5◦ for P-MCC-0G. Moreover, blending of GMP with MCC resulted in faster disintegration of powder particles during rehydration (i.e., dispersibility) compared to P-MCC-0G. Faster and more extensive release of caseins from powder particles into solution was evident with the increasing proportion of GMP, with the majority of GMP released within the first 15 min of rehydration. The results of this study will contribute to further development of formulation science for achieving enhanced solubility characteristics of high-protein dairy powder ingredients, such as MCC

Influence of transglutaminase crosslinking on casein protein fractionation during low temperature microfiltration

Low temperature microfiltration (MF) is applied in dairy processing to achieve higher protein and microbiological quality ingredients and to support ingredient innovation; however, low temperature reduces hydrophobic interactions between casein proteins and increases the solubil-ity of colloidal calcium phosphate, promoting reversible dissociation of micellar β-casein into the serum phase, and thus into permeate, during MF. Crosslinking of casein proteins using transglutam-inase was studied as an approach to reduce the permeation of casein monomers, which typically results in reduced yield of protein in the retentate fraction. Two treatments (a) 5◦ C/24 h (TA) and (b) 40◦ C/90 min (TB), were applied to the feed before filtration at 5◦ C, with a 0.1 µm membrane. Flux was high for TA treatment possibly due to the stabilising effect of transglutaminase on casein micelles. It is likely that formation of isopeptide bonds within and on the surface of micelles results in the micelles being less readily available for protein-protein and protein–membrane interactions, resulting in less resistance to membrane pores and flow passage, thereby conferring higher permeate flux. The results also showed that permeation of casein monomers into the permeate was significantly reduced after both enzymatic treatments as compared to control feed due to the reduced molecular mobility of soluble casein, mainly β-casein, caused by transglutaminase crosslinking

UK Skills and Productivity in an International Context

A nation's prosperity depends largely on its ability to raise the level of its productivity. The education level of its workforce, and how effectively the skills are used in the production processes, are considered important factors in this process. In this report we investigate the extent to which skills have contributed to recent productivity performance in the UK. We do this within a cross-country framework, where we compare the UK's productivity trajectories with those of other close competitors. We quantify the role played by different types of certified skills, both academic and vocational, taking account of the influence of other factors, such as capital investment and technological change. Furthermore, we assess the influence of intangible investments, usually excluded from published data and traditional growth studies. We use a wide range of data sources, and employ growth accounting and panel data econometric techniques. The study begins with a comprehensive review of the literature on the role of human capital in productivity and growth, from both a theoretical and empirical point of view (section 1). We then provide a description of aggregate productivity and employment trends in section 2. Section 3 contains detailed results of the growth accounting decomposition and Section 4 summarises the econometric analysis. Sections 5 and 6 outline the key findings and conclusions emerging from this analysis. The main research questions addressed in this report are: • What have been the main sources of growth in the UK and other major economies since the recession? How have these differed relative to the previous periods? • What is the link between skills and productivity/growth? How have skills contributed to growth over recent years? • What is the contribution of different types of skills to growth? Where does the UK fare better and worse compared to international competitors? • What is the role of training and other intangible assets in explaining productivity and growth outcomes? Do they interact differently with different types of skilled workers

Colloidal, tribological and sensory properties of oral nutritional supplements

This study aims to evaluate the physicochemical and sensory properties of oral nutritional supplements (ONSs). High physical stability was measured in ONSs with mean particle sizes <0.33 !m and viscosity >19.3 mPa·s. ONSs formulated with dairy-soy protein mixtures displayed low friction coefficients, whereas ONSs containing dairy proteins alone had high friction coefficient values in the boundary regime. Sensory analysis revealed low to medium liking across the products and the highest preference was found in samples with the highest perceived 'sweetness', 'vanilla aroma' and 'thickness'. The results will underpin the formulation of novel ONSs with good physical stability and sensory acceptability

The influence of temperature on filtration performance and fouling during cold microfiltration of skim milk

Changes in the physicochemical properties and distribution of constituents in skim milk during microfiltration (MF) at low temperature influence filtration performance and product composition. In this study, the influence of processing temperature within the cold MF range (4, 8 and 12 °C) on filtration performance, fouling and partitioning of proteins was investigated. MF at 4 °C required the greatest energy input due to the significantly higher (p < 0.05) viscosity of feed and retentate streams, compared to processing at 8 and 12 °C. The greatest and lowest extents of reversible and irreversible fouling during MF were observed on filtration at 12 and 4 °C, respectively. Chemical analysis of the cleaning solutions post-processing demonstrated that protein was the major foulant; the lowest protein content in the recovered cleaning solutions (50 °C water and 55 °C alkali) was measured after MF at 4 °C. The concentration of β-casein, β-lactoglobulin and α-lactalbumin in the permeate all decreased throughout MF, due to fouling of the membrane. The greatest decrease in concentration of β-casein in the permeate during MF was observed at 12 °C (18.1%) followed by 8 °C (17.1%) and 4 °C (13.6%). The results of this study provide valuable information on processing efficiency (i.e., energy consumption and protein yield) and membrane fouling during the processing of skim milk in the cold MF range

Isolation and characterisation of κ-casein/whey protein particles from heated milk protein concentrate and role of κ-casein in whey protein aggregation

peer-reviewedMilk protein concentrate (79% protein) reconstituted at 13.5% (w/v) protein was heated (90 °C, 25 min, pH 7.2) with or without added calcium chloride. After fractionation of the casein and whey protein aggregates by fast protein liquid chromatography, the heat stability (90 °C, up to 1 h) of the fractions (0.25%, w/v, protein) was assessed. The heat-induced aggregates were composed of whey protein and casein, in whey protein:casein ratios ranging from 1:0.5 to 1:9. The heat stability was positively correlated with the casein concentration in the samples. The samples containing the highest proportion of caseins were the most heat-stable, and close to 100% (w/w) of the aggregates were recovered post-heat treatment in the supernatant of such samples (centrifugation for 30 min at 10,000 × g). κ-Casein appeared to act as a chaperone controlling the aggregation of whey proteins, and this effect was stronger in the presence of αS- and β-casein.This work was supported by Dairy Levy Research Trust (project MDDT6261 “ProPart”). S. J. Gaspard was funded under the Teagasc Walsh Fellowship Scheme (reference number 2012211

Estimation of the Serviceability of Forest Access Roads

The purpose of this study was to ascribe attributes to forest access roads, to allow for estimation of their serviceability on the basis of their current condition. The approach estimates the quantity of timber that may be hauled through without critically damaging the flexible pavements. Seventy-two roads were classified on the basis of their surface conditions, subgrade material, and surface deflection as the strength parameter, for 40 and 60 t Gross Vehicle Weight. Using non-parametric statistical techniques, it was found that the surface quality of pavements was largely dependent on drainage conditions (coefficient of determination r2 = 0.84), and that a strong relationship (r2 = 0.90) also existed between drainage and the number of potholes. Pavements with peat subgrades were found to exhibit significantly higher critical deflections (5.6 mm) than pavements with mineral subgrades (1 mm), coupled with their inherent variability, it is arguable that visual classification may not be suitable for such pavements. On the basis of these results, the serviceability of individual roads, in Equivalent Standard Axle Loads (ESAL) was estimated. Potential pavement damage by a standard 6 axle timber haulage truck, of 40 t Gross Vehicle Weight, with a payload of 27 t, was evaluated to be triple that due to a standard axle (8.16 t). Increasing the payload by about 10%, increased the ESAL required to transport a unit volume of timber, hence potential pavement damage, by 20%. Consequently, a significant reduction in the serviceability of forest access roads may be incurred by small overload margins that are usually ignored

Influence of pH adjustment on physicochemical properties of microfiltration retentates of skim milk and rehydration properties of resulting powders

Effects of pH adjustment on physicochemical properties of microfiltration retentates of skim milk and rehydration of resulting micellar casein concentrate (MCC) powders were investigated. Aliquots of retentate (pH 6.9) were adjusted to pH 7.3, 7.6 or 7.6 followed by readjustment to pH 6.9 (6.9R) prior to powder preparation. The retentates with pH 6.9, 7.3, and 7.6 had casein micelle size of 179, 189 and 197 nm, respectively, while sample 6.9R had size of 183 nm, similar to retentate at pH 6.9. Higher retentate pH resulted in lower ionic calcium and higher conductivity, with sample 6.9R having higher values for both parameters than the pH 6.9 sample. The MCC powders displayed poorer wettability and enhanced dispersibility with increasing retentate pH. Interestingly, the 6.9R powder had the best wettability and dispersibility. This study demonstrated that pH-mediated modifications of the physicochemical properties of retentates improve the rehydration properties of resultant MCC powders