Dolores O'Riordan

University College Dublin | UCD · Institute of Food & Health

This study aimed to identify the amount of crude casein-hydrolysate (HMW) and a low molecular weight sub-fraction (LMW) thereof that could be incorporated into strawberry- and vanilla-flavoured beverages before the bitterness/taste became objectionable to panellists. The beverages were spiked with increasing amounts of hydrolysate and a 2-alternati...

The physical stability of emulsions containing bioactive ingredients is an important aspect of functional food development. This research investigated the effects of a bioactive dairy hydrolysate with anti-inflammatory effects on...

The cover image, by Ciara Duffy et al., is based on the Research Article In vitro evaluation of chitosan copper chelate gels as a multimicronutrient feed additive for cattle, DOI: 10.1002/jsfa.8939. The cover image, by Ciara Duffy et al., is based on the Research Article In vitro evaluation of chitosan copper chelate gels as a multimicronutrient fe...

Sodium caseinate hydrolysates (NaCaH) contain biologically active peptides that can positively influence human health. However, their intense bitterness hinders their inclusion in food products. To our knowledge, no studies have investigated whether a correlation between bitterness and bioactivity exists in NaCaH, so it is not yet known what effect...

The Temporal Dominance of Sensations (TDS) method could be an alternative approach to time‐consuming trained panels for the sensory analysis of protein hydrolysates. However, the amount of training required for accurate TDS results with hydrolysates is unclear. In addition, the masking of unpleasant aftertastes in protein hydrolysates using sweeten...

This research sought to evaluate the entrapment and in vitro release behaviour of bovine serum albumin (BSA) in chitosan-tripolyphosphate (TPP) hydrogel beads. Beads were manufactured by extruding gel forming solutions containing varying concentrations of chitosan (1–2.5%w/w) and BSA (0.25–10%w/w) into TPP solutions ranging in concentration from 0....

Bovine serum albumin (BSA), whey protein isolate (WPI), insulin and a casein hydrolysate were entrapped in chitosan-polyphosphoric acid (PPA) beads. The in vitro release of protein from the beads in simulated gastric fluid (SGF, pH 3) and simulated intestinal fluid (SIF, pH 7) was evaluated. High entrapment efficiencies were achieved for intact pro...

Practical applications: The developed food-grade fractionation system, allowed for a simple and reasonably scaled approach to separating a NaCaH, into physicochemically different fractions that could be evaluated by a sensory panel. The method of sensory evaluation used in this study, in which NaCaH samples are impregnated into paper-disks, provid...

Calcium and protein solubilisation during small-scale manufacture of semi-solid casein-based food matrices was investigated and found to be very different in the presence or absence of calcium chelating salts. Calcium concentrations in the dispersed phase increased and calcium-ion activity (ACa⁺⁺) decreased during manufacture of the matrices contai...

Casein-based food structures (58% moisture, 33% protein, 4% fat) with different calcium levels (37–1080 mg 100 g⁻¹) were manufactured by heating at 80 °C under shear. At intermediate calcium levels (358–673 mg 100 g⁻¹), homogeneous structures were formed without chelating salts (CS) after relatively short processing times. However, homogeneous stru...

This research investigated the effect of modifying the aftertaste of potato crisps on (1) temporal sensory perception and (2) appetite using three mouthwash conditions (no mouthwash, a water mouthwash, and a menthol mouthwash). For the sensory study, 17 screened female subjects were trained on the Temporal Dominance of Sensations (TDS) methodology....

This study investigated the effect of simultaneously manipulating the spatial distribution of a sweet masking agent and bitter tastant within gelatine-agar gels on bitterness suppression, using sucralose and quinine. Sixty subjects participated in a series of paired comparison tests comparing different gel designs containing both sucralose and quin...

This study investigated the effect of inhomogeneous distributions of quinine on bitterness intensity of gelatine–agar composite gels. It also investigated the effect of inhomogeneous distributions of the gel’s hydrocolloid constituents (the gelatine and agar) on the bitterness intensity of the quinine. Fifty-two screened subjects participated in fo...

This study investigated the effects of calcium chelating salts on calcium-ion activity (ACa++), calcium distribution, and protein solubility in model CaCl2 solutions (50 mmol L-1) or rennet casein dispersions (15 g/100 g). Disodium phosphate and trisodium citrate at concentrations of 10 and 30 mmol L-1 and at ratios of 1:0, 2:1, 1:1, 1:2 and 0:1 we...

Sodium caseinate hydrolysates (NaCaHs) are known to be a rich source of bioactive peptides but are also known to have a bitter taste which can make them difficult to incorporate into foods. The objective of the study was to identify whether a commercially available electronic tongue (e-tongue) could be used to identify sweeteners and flavours which...

This study investigated the kinetics of immobilisation and release of riboflavin, amino acids and peptides from whey microbeads. Blank whey microbeads were placed in solutions of the compounds. As the volume of microbeads added to the solution was increased, the uptake of the compounds increased, to a maximum of 95% for the pentapeptide and 56%, 57...

The objective of this study was to develop a sensory lexicon for dairy protein hydrolysates ( DPHs ) produced from whey and casein substrates. To create the lexicon, 25 DPHs were assessed by a trained sensory panel ( n = 8) using the spectrum descriptive analysis method using a 15‐point intensity scale. The sensory panel identified over 43 attribut...

Research indicates hydrolysed sodium caseinate can provide beneficial health effects. Their consumption could reduce the risk of chronic disease and promote human health. However, hydrolysed sodium caseinate results in bitter flavours and altered functionalities. Incorporating protein hydrolysates into foods could provide great commercial opportuni...

Whey microbeads manufactured using a cold-set gelation process, have been used to encapsulate bioactives. In this study whey microbeads were used to encapsulate riboflavin using 2 methods. Riboflavin was added to the microbead forming solution however diffusional losses of riboflavin occurred during the subsequent bead preparation. To overcome ribo...

The potential for whey based encapsulation systems to protect bioactives in the digestive tract has largely been evaluated in vitro. The aim of this study was to examine the release of riboflavin from whey microbeads in vitro and in vivo. Riboflavin was used as a model bioactive for encapsulation, as it is a stable, low molecular weight compound wh...

The ability of cold-set whey protein microgels to function as pH-sensitive immobilisation matrices for bioactives was investigated. A pH dependent interaction was confirmed between the microgels and charged bioactives and this binding was impeded by the presence of competing ions in the solution, suggesting an electrostatic interaction. The use of...

Sensory evaluation can be problematic for ingredients with a bitter taste during research and development phase of new food products. In this study, 19 dairy protein hydrolysates (DPH) were analysed by an electronic tongue and their physicochemical characteristics, the data obtained from these methods were correlated with their bitterness intensity...

The bitter taste elicited by dairy protein hydrolysates (DPH) is a well known issue for their acceptability by consumers and therefore incorporation into foods. The traditional method of assessment of taste in foods is by sensory analysis but this can be problematic due to the overall unpleasantness of the samples. Thus, there is a growing interest...

ABSTRACT The antioxidant and antiinflammatory properties of polyphenols are well documented in vitro but there are few human studies. A herbal beverage composed of chamomile, meadowsweet, and willow bark (CMW) was developed and tested for its antiinflammatory effect in a cohort of healthy adults (n = 20) during a 4-week intervention. Subjects were...

Antiinflammatory compounds in the diet can alleviate excessive inflammation, a factor in the pathogenesis of common diseases such as rheumatoid arthritis, atherosclerosis and diabetes. This study examined three European herbs, chamomile (Matricaria chamomilla), meadowsweet (Filipendula ulmaria L.) and willow bark (Salix alba L.), which have been tr...

Recently phytochemical constituents have attracted a lot of interest as sources of functional ingredients in food product formulations. However, before being incorporated into foods or beverages the stability of these bioactive constituents during post-harvest preservation procedures, in food matrices and during processing and storage must be consi...

The stability of parthenolide, the active ingredient in feverfew and a potential anti-inflammatory bioactive in beverages was evaluated at different pHs (2.9, 3.7, 4.6 and 6.0) during heat processing at 40–100°C. The residual concentration of parthenolide was analysed by High Performance Liquid Chromatography and degradation kinetics determined usi...

The objective of this study was to determine the crispiness of microwave-expanded imitation cheese and compare the results with sensory evaluation. Three cheeses were manufactured with 36%, 19%, or 15% protein; all three with 0% fat, a fourth cheese had 4% fat and 19% protein. After 3 and 9 days of storage at 5 °C, the cheeses were subjected to mic...

Imitation cheeses (48 g moisture/100 g cheese), in which the salt (NaCl) and sodium emulsifying salts were partially or wholly replaced with their potassium equivalents were manufactured. The effect of the replacement on manufacture and post-manufacture functionality (microstructure, texture, flowability, dynamic rheology and NMR T(2) relaxometry)...

Dental caries is a highly prevalent disease caused by colonisation of tooth surfaces by cariogenic bacteria, such as Streptococcus sobrinus and Streptococcus salivarius. Reducing initial adherence of such bacteria to teeth may delay onset of caries. Many foods, such as milk, can inhibit microbial adherence. In this investigation, the effect of untr...

Dental caries is a common bacterial infection, but the progression of this disease can be delayed by preventing initial attachment of cariogenic bacteria such as Streptococcus mutans to tooth surfaces. This study firstly compares the effect of untreated (UT) and enzyme-treated (ET) dairy powders on the adherence of S. mutans to hydroxylapatite (HA)...

Microwave expansion of imitation cheese is a novel way of producing a potentially health crispy snack food. This study aimed to investigate the effects of protein:starch (P:S) ratios of 37:0, 24:13, 20:17 or 16:21 and refrigerated storage (1–9 days) on the functional properties, water mobility and microwave expansion of imitation cheese. Cheese har...

IntroductionDefinition and legislationApplications and advantages of analogue cheese productsManufacture of analogue cheeseFactors influencing analogue cheese functionalityDevelopments in analogue cheeseFuture of analogue cheeseReferences

The manufacture of imitation cheese in a Farinograph was interrupted at various times, and the casein matrix formed and the free liquid were collected and analysed. During manufacture, a torque profile was generated, which showed three distinctive stages; an initial torque peak "peak-1", followed by a trough and finally a second "peak-2". Analyses...

Tannic acid (0.1–1%, w/w) and gallic acid (0.3–1%, w/w) were added to skim milk prior to acidification with GDL. The acid gelation of tannic and gallic acid fortified milk had a faster gelation time in comparison with the control gel without phenolic compounds. The addition of tannic acid and gallic acid (up to 0.8%) to the milk resulted in a highe...

Imitation cheeses (48% moisture, 0–1.5% NaCl) were manufactured using a Farinograph or Blentech cooker. The effects of NaCl reduction on cheese manufacture, functionality (assessed by texture profile analysis, flowability, dynamic rheology and microscopy), microbiological stability and sensory attributes were investigated. Reducing NaCl concentrati...

Imitation cheese (50% moisture) was manufactured in a Farinograph using different ratios of disodium orthophosphate (DSP) and trisodium citrate (TSC) as chelating or emulsifying salts (ES). The ES:casein ratio was kept constant at 0.2549mol ES/kg casein. The effects of DSP:TSC ratio on cheese manufacture and post-manufacture functional properties w...

The potential of feverfew infusions, used traditionally for the treatment of various ailments associated with pain and inflammation, was investigated as a source of nutraceuticals in the manufacture of beverages with anti-inflammatory properties. Acidified feverfew model beverages (2.9⩽pH⩽6) were stored at 5 and 22°C in order to assess the degradat...

Imitation cheese (48%, 50% and 52% moisture) was manufactured using a Farinograph. The standard emulsifying salts (ES) concentration was 1.4%, giving a casein:ES ratio of 19:12. The effect of ES reduction on cheese manufacture and functionality, assessed by texture profile analysis, heat-induced flowability and dynamic rheology, was studied. Micros...

Imitation cheeses with moisture levels of 48, 50 and 52 g/100 g were manufactured on a small-scale using a Farinograph. The batch size and mixing speed were optimised at 800 g and 50 rpm, respectively, based on observations during manufacture and torque profile obtained. Subsequently, the texture, meltability and water mobility (by NMR relaxometry)...

The objective of this study was to use mechanical and acoustic methods developed in our laboratory to monitor the changes in crispiness of a Crackerbread biscuit following equilibration at different water activities (aw). Crackerbread samples were equilibrated at aw of 0.113–0.98. The equilibrated Crackerbread samples were punctured with a cylindri...

The effects of moisture content (60–45%), and refrigerated storage (1–9days) on the functional properties, water mobility and microwave expansion of imitation cheese are investigated. Cheese hardness, elastic (G′) and viscous moduli (G″) increased with decreasing moisture content and decreased during storage. Flowability, loss tangent (tan δ) and w...

The objective of this study was to develop an acoustic measurement system for analyzing crispiness and correlate its results with sensory evaluation. Four biscuits (Crackerbread, Table Water, Rich Tea and Shortbread) were punctured using an Instron Universal Testing Machine. The force–displacement and sound amplitude–time signals were simultaneousl...

The aim of this study was to determine the effects of extraction temperature on the colour as well as on the phenolic and parthenolide content of feverfew (Tanacetum parthenium) aqueous extracts, with a view to incorporating the extracts into a beverage. Results showed that extraction temperatures of 20–70 °C yielded dark-coloured extracts with low...

The objective of this study was to investigate the effect of drying conditions on the phenolic constituents and colour of extracts of organically grown white willow and meadowsweet for incorporation into a functional beverage with potential anti-inflammatory properties. The herbs were freeze-dried, air-dried, oven or tray-dried at 30 or 70°C. The d...

Meadowsweet was extracted in water at a range of temperatures (60–100°C), and the total phenols, tannins, quercetin, salicylic acid content and colour were analysed. The extraction of total phenols followed pseudo first-order kinetics, the rate constant (k) increased from 0.09±0.02min−1 to 0.44±0.09min−1, as the temperature increased from 60 to 100...

a b s t r a c t The total phenols, apigenin 7-glucoside, turbidity and colour of extracts from dried chamomile flowers were studied with a view to develop chamomile extracts with potential anti-inflammatory properties for incorporation into beverages. The extraction of all constituents followed pseudo first-order kinetics. In general, the rate cons...

Adhesion of a micro-organism to a cell surface is often considered to be the first step in pathogenesis. Inhibiting this process may have therapeutic effects in vivo. This study investigates the inhibitory effects of various bovine whey products on the association of Salm. Typhimurium, E. coli O157:H7 and C. malonaticus (formerly Enterobacter sakaz...

Cryo-scanning electron microscopy (cryo-SEM), environmental scanning electron microscopy (ESEM), light microscopy (LM) and Fourier transform infrared (FT-IR) imaging techniques were assessed to see which was most appropriate for the examination of the microstructure of starch-containing imitation cheeses. Cheeses (54% moisture) containing four star...

The impact of starch type and concentration on the nature of water in and the rheology of imitation cheese were investigated. Imitation cheese (55% moisture) containing four starches (native, pre-gelatinised, resistant or waxy corn) at inclusion levels of 1.9%, 3.9%, 5.8%, 7.8%, or 9.9% w/w were manufactured using a Brabender Farinograph-E®. The te...

The effects of storage time prior to microwave heating on expansion of imitation cheese containing functional fibre was studied. Cheese was formulated to contain 60% moisture and 17.3% w/w resistant starch. Cheese samples were heated in a microwave oven (2540MHz) for periods of 10–100s. A 60%, 160%, 600% and 900% increase in maximum expansion was o...

Medium (13%) and low (2%) fat imitation cheeses (pH 6 or 5.5) were flavoured with 5% w/w EMC containing 16%, 28% or 47% total free fatty acids (low to high levels of hydrolysis, respectively) and were examined by a sensory panel. Aroma active short-chain free fatty acids were monitored using gas chromatographic techniques. Regardless of cheese pH o...

The aim of this study was to investigate the inhibitory effect of various dairy powders and milk constituents on the adhesion of a clinical isolate of Streptococcus mutans to hydroxylapatite (HA), an analogue of tooth enamel. Adhesion of a microorganism to a cell surface such as epithelial cells or tooth enamel is considered to be the first step in...

The objective of this study was to manufacture an imitation cheese that expands to a crispy product when heated in a microwave oven. Imitation cheese (∼18% w/w protein and 60% w/w moisture content) was formulated with varying fat content (10–0%). Fat reduction was achieved by direct replacement with resistant starch to give fat:starch ratios of 1.3...

Imitation cheese provides a useful model system to examine starch–protein interactions from a rheological and microstructural perspective. Imitation cheeses containing 3% native (amylose levels of 2.5%, 15% or 28%), pre-gelatinised, cross-linked or cross-linked and stabilised rice starch were manufactured and compared with a control (0% starch) imi...

The hydration of rennet casein and emulsification of fat were monitored throughout imitation cheese manufacture by monitoring changes in water mobility using NMR relaxometry and cheese microstructure by light microscopy. The changes in water mobility and microstructure observed are consistent with a four-stage model of protein hydration/matrix deve...

Imitation cheeses were manufactured with increasing levels (0–20%, w/w) of native wheat starch in partial or total replacement of rennet casein protein. With increased addition of native wheat starch up to 9% (w/w), irregular starch particles (sometimes horseshoe-shaped) became more numerous and disruptive of the protein structure. Differential sca...

The rheological properties and microstructure of imitation cheeses containing 3%, w/w, pre-gelatinised maize, waxy-maize, wheat, potato or rice starches were compared to a control (0%, w/w, starch). Dispersions of pre-gelatinised rice or waxy-maize starches with casein had the highest viscosities following heating at 80°C compared to casein heated...

Enzyme-modified cheeses (EMCs) are used to impart flavour to imitation cheese products. Cheeses (pH 6 or 5.5) were formulated with 5% w/w EMC, having low, medium or high levels of lipolysis and were examined by a sensory panel. Free fatty acid analyses were performed using SPME/GC. The flavour profile of the flavoured cheeses was affected by EMC co...

The effect of moisture and resistant starch concentration on the water activity (aw) and water sorption of imitation cheese was investigated. The Guggenheim–Anderson–deBoer (GAB) equation was found to be a good description of the experimental moisture sorption isotherms. Inclusion of starch in cheese increased moisture sorption over the aw range st...

Imitation cheeses were manufactured with increasing levels (0–9%, w/w) of pre-gelatinised maize starch in partial replacement of rennet casein. At increased starch levels, longer processing times (10min at 78°C using 9%, w/w starch) were necessary compared to the control (5min) because of the reduced protein present to emulsify/stabilise the fat dr...

In this study the impact of cooker design and/or blade/auger speed on the functional properties of imitation cheese was investigated. Cheeses with similar compositions (48% moisture) were manufactured using water, rennet casein, rapeseed and hydrogenated palm oil and emulsifying salts in a twin-screw (Blentech) or a single-blade cooker (Stephan). T...

The rheological and proteolytic changes in imitation cheeses containing 3% native (2.5, 15 or 28% amylose levels), pregelatinised, cross-linked or cross-linked and stabilised rice starch were compared to a control (0% starch) with storage time. After 180 days, the control had significant decreases in textural hardness (from 136.5 to 114.9 Newtons)...

Different starch types were examined for their effects on the hydration, solubility and viscosity of rennet casein dispersions to model the behaviour of these hydrocolloids in foods such as imitation cheese. Rennet casein dispersed with the aid of calcium-chelating salts and heat had a peak particle size and apparent viscosity at 40°C before both d...

Different starch types were examined for their effects on dilute model oil-in-water systems containing casein. Inclusion of the higher amylose starch types of maize, wheat and potato starch resulted in the greatest increase in emulsion particle size (0.78-89μm) compared to the control (0.42μm), which had no starch. All starch types significantly in...

The physical properties of imitation cheeses containing 21.3% dry matter (DM) resistant starch with moisture levels of 52–60%, as well as cheeses (60% moisture) containing 21.3–43.2% DM resistant starch were examined. Flowability of the heated cheese was assessed by an empirical method; the textural properties by texture profile analysis and dynami...

The effects of vaious reagents on the rheological properties of heat-induced (90°C) gels formed from plasma protein solutions (pH 9.0) were studied. Both propylene glycol (5–20%, w/v) and ethanol (5–20,%, w/v), which enhance hydrogen and electrostatic interactions, increased gel compressive strength, whereas mercaptoethanol (25–100 mM) which reduce...

The possibility of using shear-induced inulin gels or heated inulin solutions to replace fat in imitation cheese was investigated. Imitation cheeses with a moisture content of 54 g/100 g were manufactured by replacing 0 (control, 21.7 g fat/100 g cheese), 23% or 63% of the fat with shear-induced inulin gel. Imitation cheeses with 54 g and 56 g mois...

The rheology and microstructure of a control imitation cheese were compared with cheeses containing Novelose240 (N240, native resistant starch) or Novelose330 (N330, retrograded resistant starch), as a source of fibre to replace fat. Hardness increased linearly with fibre content and to a greater extent for N330 than for N240. Cohesiveness increase...

Films were formed from heated whey protein isolate (WPI) solutions (heated [H] films) and from unheated WPI solutions following adjustment to pH 11, with subsequent readjustment to pH 7 (unheated, readjusted [UR] films) or without readjustment to pH 7 (unheated, unadjusted films [UU] films). UU and UR films had significantly lower % elongation, ten...

Effects of glycerol, xylitol, and sorbitol on selected physical properties of whey protein isolate (WPI) films were examined. Increasing glycerol or sorbitol content led to increases in moisture content, water vapor permeability, and % elongation; and decreases in tensile strength, elastic modulus, and glass transition temperatures of the films. In...

A range of films were formed using different proportions of heated (80C for 30min) and unheated whey protein isolate (WPI) solutions. The films, with lower proportions of heated WPI solution had lower percentage elongation, tensile strength and Young's modulus, higher solubility and, in general, similar water vapour permeability, compared with a fi...

A common theme in the many challenges currently facing universities is the need for transparency and comparability within and between curricula. Emerging evidence from University College Dublin is starting to suggest that a constructively aligned curriculum can promote both of these features. In so doing, it can help students to study more efficien...

The physical properties of thin films (25–30μm) made from mixtures of sodium caseinate (NaCas) and whey protein isolate (WPI) were investigated. Films were formed by mixing solutions of NaCas (2.5% w/w protein), plasticised with glycerol (NaCas–gly) at a glycerol:protein ratio of 0.32, with WPI solutions (2.3% w/w protein), plasticised (WPI-gly) at...

Sodium caseinate solutions (2.5 g protein/100 g solution) containing glycerol (gly) at gly:protein ratios of 0, 0.08, 0.16, 0.24 or 0.32 w/w were dried over 48 h at 50±5% RH and 23±2 °C to form transparent flexible films of approximately 35 μm thickness. Maximum load, tensile strength and elastic modulus of films decreased and the moisture content...

Increasing moisture content may be a practical and cost-effective means to control the functional properties of imitation cheese. Imitation cheeses with moisture contents of 46, 50, 52 and 54g/100g were manufactured. An increase in the moisture content of the imitation cheese resulted in significantly increased meltability, tany = 2.2272x2 - 215.31...

The effect of varying thickness on the water barrier properties, tensile properties and sensory characteristics of glycerol-plasticised whey protein isolate (WPI) films was investigated. Thickness was varied by preparing films with increasingly dilute film forming WPI solutions in the range 9.5–2.3 g protein/100 g. All films had a glycerol to prote...

Emulsions of menhaden oil and sodium caseinate (NaCas) incorporating carbohydrates of varying dextrose equivalence (DE) were spray-dried to yield encapsulated fish oil powders. The effects of carbohydrate DE (5.5-38), core/wall ratio and NaCas/carbohydrate ratio on microencapsulation efficiency (ME) and oxidative stability of spray-dried emulsions...

The water vapour permeability (WVP), mechanical strength, equilibrium moisture content (MC), glass transition temperature and opacity of whey protein isolate films plasticised with different levels of glycerol (Gly) (glycerol:protein (Gly:Pr)=0.5, 0.6 and 0.7) and containing different levels of added soya oil (oil:protein (Oil:Pr) ratio=0.0, 0.2, 0...

Emulsions of soya oil in mixed solutions of sodium caseinate (Na Cas) and carbohydrates of various dextrose equivalence (DE) were prepared and subsequently spray-dried to yield powders with 20–75% oil. Effects of DE (0–50), core/wall and Na Cas/carbohydrate ratios and total solids concentration on emulsion oil droplet size and microencapsulation ef...

Gum arabic solutions (10% w/v) were emulsified with soy oil at oil/gum ratios of 0.25-5.0. At oil/gum ratios <1.0, it was established that gum arabic could be partially replaced with a nonsurfactant carbohydrate. To assess different carbohydrates as replacers for gum arabic, emulsions and spray-dried emulsions of soy oil and mixed solutions (10% w/...

ABSTRACT Emulsions containing various levels of soya oil dispersed in solutions of whey protein concentrate (WPC) 75 (5% w/v) were spray-dried to yield powders with oil contents ranging from 20% to 75% (w/w). The effect of homogenizing pressure and oil/protein ratio on oil globule size distributions and protein load of the emulsions and the microen...

ABSTRACT Imitation cheeses containing 3% native maize, waxy-maize, wheat, potato or rice starch were manufactured and the microstructure, meltability, texture and dynamic rheology of these products were compared to a control (0% starch). Fat globules in starch-containing products (except potato) were smaller than in the control as evidenced by elec...

Emulsions were prepared with 5% (w/v) solutions of sodium caseinate (Na Cas) and soy oil at oil/protein ratios of 0.25-3.0 by homogenization at 10--50 MPa. Emulsions were spray-dried to yield powders with 20--75% oil (w/w). Emulsion oil droplet size and interfacial protein load were determined. Microencapsulation efficiency (ME), redispersion prope...

Moisture sorption isotherms (aw=0.115–0.94) were measured for a series of whey protein isolate (WPI) edible films prepared with different amounts of glycerol as a plasticizer (glycerol:total non-volatile material G=0–0.5) and for native WPI. The moisture sorption characteristics of the native protein were similar to those of the G=0 films and the e...

Imitation cheese was manufactured with various levels of pre-gelatinized maize starch. Melt characteristics were assessed by an empirical melt test, based on the Olson and Price method. Using dynamic rheology, the storage modulus (G′), the loss modulus (G”) and the loss angle (tan δ) were measured as a function of temperature (22-100°C). Melt-abili...

Emulsions of gum arabic solutions (10% w/w) and soya oil at oil/gum ratios of 0.25−5.0 were prepared by homogenization at 20 MPa. The resulting emulsions were subsequently spray-dried to produce powders with oil contents ranging from 20 to 82% (w/w). Lipid globule size distributions and viscosities of the emulsions were determined, and particle siz...

The rheological properties of plasma protein gels were markedly affected by protein concentration, pH, heating temperature and time and measuring temperature.Gel strength increased with increasing protein concentration (6–18%), pH (4·0–9·0), heating temperature (60–90°C) and time (15–60 min), but decreased with increasing measuring temperature (10–...

Added salts influenced the rheological properties of heat-induced plasma protein gels. Gel strength increased in the presence of 0·01m added CaCl2 and 0·02m added MgCl2. However, gel strength was reduced at higher concentrations of these salts. The ability of plasma protein gels to recover following deformation was lower than for the control (no ad...