Influence of calcium-binding salts on heat stability and fouling of whey protein isolate dispersions

peer-reviewedThe effect of the calcium-binding salts (CBS), trisodium citrate (TSC), tripotassium citrate (TPC) and disodium hydrogen phosphate (DSHP) at concentrations of 1–45 mm on the heat stability and fouling of whey protein isolate (WPI) dispersions (3%, w/v, protein) was investigated. The WPI dispersions were assessed for heat stability in an oil bath at 95 °C for 30 min, viscosity changes during simulated high-temperature short-time (HTST) and fouling behaviour using a lab-scale fouling rig. Adding CBS at levels of 5–30 mm for TSC and TPC and 25–35 mm for DSHP improved thermal stability of WPI dispersions by decreasing the ionic calcium (Ca2+) concentration; however, lower or higher concentrations destabilised the systems on heating. Adding CBS improved heat transfer during thermal processing, and resulted in lower viscosity and fouling. This study demonstrates that adding CBS is an effective means of increasing WPI protein stability during HTST thermal processing

A comparison of pilot-scale supersonic direct steam injection to conventional steam infusion and tubular heating systems for the heat treatment of protein-enriched skim milk-based beverages

peer-reviewedDirect supersonic steam injection, direct steam infusion, and indirect tubular heating were each applied to protein-enriched skim milk-based beverages with 4, 6 and 8% (w/w) total protein, and the effect of final heat temperature on the physical properties of these beverages was investigated. Supersonic steam injection resulted in significantly lower levels of denaturation of β-lactoglobulin (34.5%), compared to both infusion (76.3%) and tubular (97.1%) heating technologies. Viscosity, particle size and accelerated physical stability of formulations did not differ significantly between the heating technologies, while noticeable colour differences due to heat treatment (mainly attributed to increasing b* value) were observed, particularly for tubular heating. Overall, the extent of protein denaturation in high-protein dairy products was significantly influenced by the particular heating technology applied. The application of supersonic steam injection technology, with rapid heating and high shear characteristics, may enable differenciated product characteristics for ready-to-drink ambient-delivery high-protein dairy beverages. Industrial relevance: The design and application of novel direct supersonic steam injection technology was comprehensively studied and found to provide significant benefits over direct steam infusion and indirect tubular heating technologies for skim milk-based protein beverages. This type of injection heating system resulted in heat-treated formulations with lower levels of denatured whey proteins, compared to tubular and infusion heating, offering an alternative opportunity to the industry in terms of producing shelf-stable dairy protein beverages

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

Composition, morphology and pasting properties of Orchis anatolica tuber gum

Orchis anatolica (O. anatolica) tuber is commonly used in the production of Salep gum or O. anatolica tuber gum (OaG) for use as a thickener, flavouring agent, gelling agent, film former and emulsifier in the food industry. The aim of this study was to investigate the chemical composition, physical, morphological and pasting properties of OaG. Physical and morphological analyses, and pasting properties of OaG were analysed using static light scattering, scanning electron microscopy, light microscopy and rotational rheometry, respectively. Volume-weighted mean particle diameter (D [4,3]) value of OaG was 180 ± 1.25 μm. OaG was composed mainly of starch (41.6%), dietary fiber (32.3%) and glucomannan (18.5%). The powder of OaG had irregular shaped particles with smooth surfaces and round edges. After pasting treatment, the initial and final viscosity values of the OaG dispersions at a concentration of 0.5% OaG were 33.7 ± 0.24 and 34.3 ± 0.45 mPa.s, whereas, the corresponding values at a concentration of 2.5% OaG were 1193 ± 92.0 and 1437 ± 83.3 mPa.s, respectively. The glucomannan and dietary fiber components and their possible interactions with starch, in OaG appear to have influenced the peak temperature and viscosity on pasting, due to limitation of the leaching of amylose and amylopectin from starch granules. Therefore, O. anatolica tuber gum, a complex biopolymer, can provide interesting and unique functionality to the food industry in the development of novel food structures

Is fibromyalgia associated with a unique cytokine profile?

Objectives: The aetiology of primary chronic pain syndromes (CPS) is highly disputed. We performed a systematic review and meta-analysis aiming to assess differences in circulating cytokines levels in patients with diffuse CPS (fibromyalgia) versus healthy controls (HC). Methods: Human studies published in English from the PubMed and MEDLINE/Scopus and Cochrane databases were systematically searched from inception up to January 2020. We included full text cross-sectional or longitudinal studies with baseline cytokine measurements, reporting differences in circulating cytokine levels between fibromyalgia patients and HC. Random-effects meta-analysis models were used to report pooled effects and 95% CIs. This study is registered with PROSPERO(CRD42020193774). Results: Our initial search yielded 324 papers and identified 29 studies (2458 participants) eligible for systematic review and 22 studies (1772 participants) suitable for meta-analysis. The systematic analysis revealed reproducible findings supporting different trends of cytokine levels when fibromyalgia patients were compared to HC, while the chemokine eotaxin, was consistently raised in fibromyalgia . Meta-analysis showed significantly increased tumour necrosis factor alpha (TNF-α) (SMD=0.36, p = 0.0034, 95%CI=0.12-0.60; I2=71%, Q2 p = 0.0002), interleukin (IL)-6 (SMD=0.15, p = 0.045, %95CI=0.003-0.29; I2=39%, Q2 p = 0.059), IL- 8 (SMD=0.26, p = 0.01, 95%CI =0.05-0.47; I2=61%, Q2 p = 0.005) and IL-10 (SMD=0.61; %95 = 0.34-0.89, p < 0.001; I2 = 10%, Q2 p = 0.34) in fibromyalgia patients compared to HC. Conclusion: We found evidence of significant differences in the peripheral blood cytokine profiles of fibromyalgia patients compared to HC. However, the distinctive profile associated with fibromyalgia includes both pro-inflammatory (TNF-α, IL-6, IL-8), and anti-inflammatory cytokines (IL-10) in pooled analysis, as well as chemokine (eotaxin) signatures. Further research is required to elucidate the role of cytokines in fibromyalgia

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

Building an end user focused THz based ultra high bandwidth wireless access network: The TERAPOD approach

The TERAPOD project aims to investigate and demonstrate the feasibility of ultra high bandwidth wireless access networks operating in the Terahertz (THz) band. The proposed TERAPOD THz communication system will be developed, driven by end user usage scenario requirements and will be demonstrated within a first adopter operational setting of a Data Centre. In this article, we define the full communications stack approach that will be taken in TERAPOD, highlighting the specific challenges and aimed innovations that are targeted

Analysis of Johne’s disease ELISA status and associated performance parameters in Irish dairy cows

peer-reviewedBackground Infection with Mycobacterium avium subspecies paratuberculosis (MAP) has been associated with reductions in milk production in dairy cows and sub optimal fertility. The aim of this study was to highlight the production losses associated with testing MAP ELISA positive in Irish dairy cows. Secondary objectives included investigation of risk factors associated with testing MAP ELISA positive. A survey of management practices on study farms was also conducted, with examination of associations between management practices and herd MAP status. Blood samples were collected from 4188 breeding animals on 22 farms. Samples were ELISA tested using the ID Screen Paratuberculosis Indirect Screening Test. Production parameters examined included milk yield, milk fat, milk protein, somatic cell count, and calving interval. The association between MAP ELISA status and production data was investigated using multi-level mixed models. Logistic regression was used to identify risk factors for testing JD blood ELISA positive at individual cow level and to identify associations between farm management practices and herd MAP status. Results Data were available for 3528 cows. The apparent prevalence recorded was 7.4 %. Mixed model analysis revealed no statistically significant association between testing MAP ELISA positive and dairy cow production parameters. Risk factors associated with testing positive included larger sized herds being over twice more likely to test positive than smaller herds (OR 2.4 P = <0.001). Friesians were less likely to test positive relative to other breeds. A number of study farmers were engaged in management practices that have previously been identified as high risk for MAP transmission e.g., 73.1 % pooled colostrum and 84.6 % of study farmers used the calving area to house sick animals throughout the year. No significant associations however, were identified between farm management practices and herd MAP status. Conclusion No production losses were identified; however an apparent prevalence of 7.4 % was recorded. With the abolition of EU milk quotas herd size in Ireland is expanding, as herds included in this study were larger than the national average, results may be indicative of future JD levels if no JD control programmes are implemented to minimise transmission

Influence of emulsifier type on the spray-drying properties of model infant formula emulsions

The objective of this study was to compare the drying performance and physicochemical properties of model infant formula (IF) emulsions containing 43, 96 and 192 g L−1 protein, oil and maltodextrin (MD), respectively, prepared using different emulsifier systems. Emulsions were stabilised using either whey protein isolate (WPI), whey protein hydrolysate (WPH; DH 8%), WPH + CITREM (9 g L−1), WPH + lecithin (5 g L−1) or WPH conjugated with maltodextrin (DE 12) (WPH-MD). Homogenised emulsions had 32% solids content and oil globules with mean volume diameter WPH + LEC > WPH > WPH- MD > WPI, WPI > WPH > WPH- MD > WPH + LEC > WPH + CIT and WPH- MD > WPI > WPH > WPH + LEC > WPH + CIT, respectively. Additionally, differences in wettability, surface topography and oil globule distribution within the powder matrix and in reconstituted powders were linked to the emulsifier system used. Inclusion of the WPH-MD conjugate in the formulation of IF powder significantly improved drying behaviour and physicochemical properties of the resultant powder, as evidenced by lowest powder build-up during drying and greatest emulsion quality on reconstitution, compared to the other model formula systems