The effect of food-grade low-molecular-weight surfactants and sodium caseinate on spray drying of sugar-rich foods
- Authors: Jayasundera, Mithila , Adhikari, Benu , Adhikari, Raju , Aldred, Peter
- Date: 2010
- Type: Text , Journal article
- Relation: Food Biophysics Vol. 5, no. 2 (2010), p. 128-137
- Full Text: false
- Description: The effect of low-molecular-weight surfactants (LMS) and sodium caseinate (NaCas) on spray drying of sugar-rich foods has been studied. Sucrose and NaCas were selected as a model sugar-rich food and protein, respectively. Sodium stearoyl lactylate (SSL) and Polysorbate 80 (Tween 80) were chosen as model ionic and nonionic LMS. Sucrose-NaCas solutions with the solids ratio of 99.5:0.5 in the absence and presence (0.01% and 0.05%) of SSL and Tween 80 were prepared. The feed solutions had 25% solid concentration in all cases. The dynamic surface tension (DST) values of the solutions were measured for 100 s and the solutions were subsequently spray dried at inlet and outlet temperatures of 165 and 65 °C, respectively. The glass-rubber temperature (Tg-r), the surface elemental composition and amorphous-crystalline nature of the powders were also determined. At these concentrations and experimental time frame, it was found that the proteins preferentially migrated to the air-water interface reasonably swiftly. The addition of LMS resulted in partial or complete displacement of the proteins from the air-water interface. For spray-drying trials with the yield of 82.0%, it was found that 52.0% of the powder particle surface was covered with proteins. The powder recovery was greatly reduced by the LMS concentration and type. At 0.05% on dry solid basis, in the case of nonionic surfactant (Tween 80), the displacement of protein from the surface was such that no powder was recovered. The ionic surfactant (SSL) displaced 2.0% and 29.3% proteins from the droplet surface at concentrations of 0.01% and 0.05%, respectively, resulting in 75.5 ± 1.8% and 30.1 ± 1.4% powder yield. The Tg-r results revealed that the amount of protein required for successful spray drying of the sucrose-protein solution depends on the amount of proteins present in the droplet surface but not in the bulk. X-ray diffraction and scanning electron microscopy results confirmed that the powders of both sucrose-NaCas and sucrose-NaCas with 0.01% SSL were mostly amorphous, while those with sucrose-NaCas-Tween 80 (0.01%) and sucrose-NaCas-SSL (0.05%) were crystalline. © 2010 Springer Science+Business Media, LLC.
Surface modification of spray dried food and emulsion powders with surface-active proteins : A review
- Authors: Jayasundera, Mithila , Adhikari, Benu , Aldred, Peter , Ghandi, Amir
- Date: 2009
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 93, no. 3 (2009), p. 266-277
- Full Text:
- Reviewed:
- Description: Spray drying is a well-established and widely used method for transforming a wide range of liquid food products into powder form. Stickiness is the limitation in spray drying of different sugar and acid-rich food products. To minimize this problem process and material science based approaches are in place. However, these remedies have their own drawbacks. Surface modification of droplets/particles is a novel way to minimize stickiness. It is timely that the research efforts on surface modification of droplets/particles be reviewed. Therefore, this review highlights the recent research dealing with surface modification of emulsions and spray dried powders. The theoretical foundation, mechanisms and methods used to achieve surface modification of food and emulsion powders are highlighted. © 2009 Elsevier Ltd. All rights reserved.
Water uptake and its impact on the texture of lentils (Lens culinaris)
- Authors: Joshi, Matina , Adhikari, Benu , Panozzo, Joe , Aldred, Peter
- Date: 2010
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 100, no. 1 (2010), p. 61-69
- Full Text: false
- Reviewed:
- Description: Water uptake behavior of three cultivars of lentils (Boomer, French-green and Nugget) was studied at three different hydration temperature regimes (room temperature, 50 °C and 85 °C). Boomer had the highest amount of water uptake capacity (74.60 g water/100 g of seeds) at room temperature (20 °C) which can be linked with its pore properties. French-green lentils imbibed the largest amount of water at elevated soaking temperatures (50 °C and 85 °C) and can be attributed to its higher seed surface area to volume ratio, high protein content and relatively thinner seed coat. Water uptake at elevated temperatures (50 °C and 85 °C) were predicted by a two parameter Mitscherlich model (R2 > 0.99,
- Description: 2003008231
The effect of protein types and low molecular weight surfactants on spray drying of sugar-rich foods
- Authors: Jayasundera, Mithila , Adhikari, Benu , Adhikari, Raju , Aldred, Peter
- Date: 2010
- Type: Text , Journal article
- Relation: Food Hydrocolloids Vol. 25, no. 3 (2010), p. 459-469
- Full Text:
- Reviewed:
- Description: The effect of protein types and low molecular weight surfactants (LMS) on spray drying of sugar-rich foods has been studied using sucrose as a model sugar and sodium caseinate (NaCas) and pea protein isolate (PPI) as model proteins. Sodium stearoyl lactylate (SSL) and Polysorbate 80 (Tween-80) were chosen as model ionic and non-ionic LMS. The sucrose:NaCas and sucrose:PPI solid ratios were maintained at (99.5:0.5) and (99:1), respectively and spray-dried maintaining 25% solids in feed solutions. It was found that the proteins preferentially migrated to the air-water interface reasonably swiftly and the addition of LMS resulted into partial or complete displacement of the proteins from the air-water interface. More than 80% of amorphous sucrose powder was produced with the addition of 0.13% (w/w) of NaCas in feed solution. PPI was not as effective and produced less than 50% recovery even at 0.26% (w/w) in feed. Addition of 0.01-0.05% SSL displaced 2.0% and 29.3% of proteins from the surface of sucrose-NaCas-SSL droplet, respectively, resulting in a 6.5 ± 1.2% to 51.9 ± 1.9% reduction in powder recovery. The extent of protein displacement was higher when SSL was added into sucrose-PPI solution; however, the powder recovery was not much affected. The addition of 0.01% Tween-80 in sucrose-NaCas solution resulted in a 48.2 ± 1.5% reduction in powder recovery and at 0.05% concentration, it displaced a substantial amount or all the NaCas from the droplet surface and no powder was recovered. The addition of 0.01% and 0.05% Tween-80 into sucrose-PPI solution resulted into very low powder recoveries (24.9 ± 0.4% and 29.5 ± 1.8%, respectively). The glass transition temperature (Tg) results revealed that the amount of protein required for successful spray drying of sucrose-protein solutions depends on the amount of proteins present on the droplet surface but not on the bulk concentration. X-ray diffraction and scanning electron microscopy results showed that the powders of sucrose-NaCas/PPI and sucrose-NaCas/PPI with 0.01% SSL were mostly amorphous while those with sucrose-NaCas/PPI-Tween-80 (0.01%), sucrose-PPI-Tween-80 (0.05%) and sucrose-NaCas/PPI-SSL (0.05%) were crystalline. © 2010 Elsevier Ltd. All rights reserved.
Drying and denaturation kinetics of whey protein isolate (WPI) during convective air drying process
- Authors: Haque, M. Amdadul , Putranto, Aditya , Aldred, Peter , Chen, Jie , Adhikari, Benu
- Date: 2013
- Type: Text , Journal article
- Relation: Drying Technology Vol. 31, no. 13-14 (2013), p. 1532-1544
- Full Text: false
- Reviewed:
- Description: The denaturation and drying kinetics of whey protein isolate (WPI) in a convective drying (CD) environment was measured using single droplet drying experiments. The moisture content and temperature histories during drying of WPI droplets were predicted using reaction kinetics-based models. The denaturation kinetics of WPI in the CD process was predicted using first-order reaction kinetics considering the denaturation rate constant to be moisture content and temperature dependent. Single droplets of WPI (10% [w/v], 2.0 ± 0.1 mm initial diameter) were used throughout these experiments. The drying experiments were carried out at two temperatures (65 and 80°C) at a constant air velocity (0.5 m/s) for 600 s. The extent and nature of the denaturation of WPI during the CD was compared with those in isothermal heat treatments (IHT) at the same medium temperatures. The denaturation of WPI was 68.31% in convective air drying at 65°C and 600 s and it was 10.79% in the IHT at the same temperature and time. The stress due to dehydration and the exposure time were found to be responsible for the denaturation of WPI in the CD process and long exposure time was found to be responsible for its denaturation in the IHT process. At the media temperature of 80°C, the denaturation loss of WPI was 90.00 and 68.73% in IHT and CD processes, respectively. Both the thermal (moist heat) and dehydration stresses were found to be responsible for denaturation of WPI during CD process and very high thermal stress was found to be responsible for denaturation of WPI during the IHT. There was good agreement between the experimental and reaction engineering approach (REA)-predicted moisture content and temperature histories. The experimental moisture content and temperature histories were followed by the respective REA predictions within 6.5% (R 2 = 0.995) and 3% (R 2 = 0.981) errors, respectively. The denaturation kinetics of WPI during CD was predicted well (R 2 = 0.95 - 0.98; average error = 6.5 ± 0.5%) by a first-order reaction kinetics model. © 2013 Copyright Taylor and Francis Group, LLC.
- Description: C1
Physicochemical and functional properties of lentil protein isolates prepared by different drying methods
- Authors: Joshi, Matina , Adhikari, Benu , Aldred, Peter , Panozzo, Joe , Kasapis, Stefan
- Date: 2011
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 129, no. 4 (2011), p. 1513-1522
- Full Text: false
- Reviewed:
- Description: Lentil protein isolate (LPI) extract was converted into powder by freeze drying, spray drying and vacuum drying. Differences in particle size distribution, protein subunit composition and colour and surface morphology were observed amongst the three drying methods. Spray and freeze-dried LPI powders exhibited higher solubility (81% and 78%, respectively) compared to vacuum dried powders (50%). The spray dried powders showed a low water absorption capacity (0.43 ± 0.02 g/g) compared to freeze (0.48 ± 0.02 g/g) and vacuum-dried (0.47 ± 0.01 g/g) LPI powders. Spray and freeze-dried powders displayed better gelation ability and higher gel strength, compared to vacuum-dried powder. Both spray and freeze-dried gels showed typical viscoelastic gel characteristics, with G′ dominating over G″ and very low loss tangent. The holding time required for gelation of vacuum dried powder at 90 °C was significantly longer, compared to spray and freeze dried powders. Hence, drying methods used for preparation of lentil protein isolate powders can affect physicochemical and associated functional properties. © 2011 Elsevier Ltd. All rights reserved.
The effects of proteins and low molecular weight surfactants on spray drying of model sugar-rich foods: Powder production and characterisation
- Authors: Jayasundera, Mithila , Adhikari, Benu , Adhikari, Raju , Aldred, Peter
- Date: 2011
- Type: Text , Journal article
- Relation: Journal of Food Engineering Vol. 104, no. 2 (2011), p. 259-271
- Full Text: false
- Reviewed:
- Description: The effects of proteins and low molecular weight surfactants (LMS) on spray drying and powder characteristics of model sugar-rich foods have been studied. Fructose and sucrose were selected as model sugar-rich foods and sodium caseinate (NaCas) was selected as a model protein. Sodium stearoyl lactylate (SSL) and Polysorbate 80 (Tween-80) were chosen as model ionic and non-ionic low molecular weight surfactants. The feed solutions for spray drying had 25% solid concentration in all. To achieve identical powder recoveries of the order of 80% much higher NaCas:fructose ratio (30:70) was required compared to NaCas:sucrose ratio (0.5:99.5) which corresponded to 7.89% and 0.13% of sodium caseinate (initial bulk concentration), respectively. There was no change in powder recovery when the SSL concentration was increased from 0.01% to 0.05% in fructose-NaCas-SSL solution and also addition of 0.01% Tween-80 into fructose-NaCas solution did not affect the powder recovery (76.7 ± 2.3%), however, it was slightly affected with the increase of Tween-80 to 0.05% (69.0 ± 1.9%). At NaCas concentration above critical micelle concentration of NaCas (3% w/w), the presence of up to 0.05% low molecular weight surfactants had either no effect or minimal effect on the surface coverage of the droplets/particles and also on the powder recovery depending on the nature of the low molecular weight surfactants. The surface protein coverage and the recovery of the powder in sucrose-protein systems were very sensitive in the presence of low molecular weight surfactants due to being below the critical micelle concentration of NaCas. SSL displaced 2.0% and 29.3% of proteins from the droplet surface of sucrose-NaCas-SSL, respectively, when its concentration was varied from 0.01% to 0.05% thereby reducing the powder recovery from 75.5% to 30%. The addition of 0.01% Tween-80 in sucrose-NaCas solution resulted in a 48.2 ± 1.5% reduction in powder recovery and at 0.05% concentration, it displaced a substantial amount of NaCas from the droplet surface and no powder was recovered. These phenomena are explained on the basis of surface-glass transition temperature, dynamic surface tension, nature of surfactants and glass transition temperature of sugars used. X-ray diffraction and scanning electron microscopy results showed that the powders of sucrose-NaCas, sucrose-NaCas with 0.01% SSL and all powders of fructose were amorphous. © 2010 Elsevier Ltd. All rights reserved.
Drying and denaturation characteristics of whey protein isolate in the presence of lactose and trehalose
- Authors: Haque, M. Amdadul , Chen, Jie , Aldred, Peter , Adhikari, Benu
- Date: 2015
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 177, no. (2015), p. 8-16
- Full Text: false
- Reviewed:
- Description: The denaturation kinetics of whey protein isolate (WPI), in the presence and absence of lactose and trehalose, was quantified in a convective air-drying environment. Single droplets of WPI, WPI-lactose and WPI-trehalose were dried in conditioned air (2.5% RH, 0.5 m/s air velocity) at two temperatures (65°C and 80°C) for 500 s. The initial solid concentration of these solutions was 10% (w/v) in all the samples. Approximately 68% of WPI was denatured when it was dried in the absence of sugars. Addition of 20% trehalose prevented the irreversible denaturation of WPI at both temperatures. Thirty percent lactose was required to prevent denaturation of WPI at 65°C and the same amount of lactose protected only 70% of WPI from denaturation at 80°C. The secondary structures of WPI were found to be altered by the drying-induced stresses, even in the presence of 20% trehalose and 30% lactose.
Surface protein coverage and its implications on spray-drying of model sugar-rich foods: Solubility, powder production and characterisation
- Authors: Jayasundera, Mithila , Adhikari, Benu , Howes, Tony , Aldred, Peter
- Date: 2011
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 128, no. 4 (2011), p. 1003-1016
- Full Text: false
- Reviewed:
- Description: We have investigated the amount of protein required to produce amorphous sugar powders through spray-drying. Pea protein isolate was used as a model plant protein and sodium caseinate was used as a model dairy protein. Powder recovery in a laboratory spray dryer was used as a measure of the ease of spray drying for a given formulation. More than 80% of amorphous sucrose and fructose was produced with the addition of sodium caseinate, while the pea protein isolate was able to produce only recoveries of less than 50% of amorphous sucrose. Sensitivity of low molecular weight surfactants has been demonstrated using both ionic (sodium stearoyl lactylate) and non-ionic (polysorbate-80) surfactants. Spray-dried powders were subjected to physico-chemical characterisation and dissolution experiments. The maximum solubility of all powders was obtained after 5 min of dissolution. The solubility of the sodium caseinate increased by 6-7% in the presence of fructose and low molecular weight surfactants. The solubility of the amorphous powders of sucrose-pea protein isolate was found to be lower than amorphous powders of sucrose-sodium caseinate and fructose-sodium caseinate. The addition of sucrose in water increased the solubility of the pea protein isolate from 16.84% to more than 83%. The non-ionic surfactant (Tween-80) has reduced the solubility of sucrose-pea protein isolate-Tween-80 powders significantly (p < 0.05) compared to those of sucrose-pea protein isolate-sodium stearoyl lactylate powders. The solubility of sucrose-sodium caseinate powders was comparable to that of pure sodium caseinate, indicating that addition of sucrose into 0.13% sodium caseinate does not have any significant effect on the solubility of this protein at this concentration. © 2011 Elsevier Ltd. All rights reserved.
Physicochemical and functional characteristics of lentil starch
- Authors: Joshi, Matina , Aldred, Peter , McKnight, Stafford , Panozzo, Joe , Kasapis, Stefan , Adhikari, Raju , Adhikari, Benu
- Date: 2013
- Type: Text , Journal article
- Relation: Carbohydrate Polymers Vol. 92, no. 2 (2013), p. 1484-1496
- Full Text: false
- Reviewed:
- Description: The physicochemical properties of lentil starch were measured and linked up with its functional properties and compared with those of corn and potato starches. The amylose content of lentil starch was the highest among these starches. The crystallinity and gelatinization enthalpy of lentil starch were the lowest among these starches. The high amylose: amylopectin ratio in lentil starch resulted into low crystallinity and gelatinization enthalpy. Gelatinization and pasting temperatures of lentil starch were in between those of corn and potato starches. Lentil starch gels showed the highest storage modulus, gel strength and pasting viscosity than corn and potato starch gels. Peleg's model was able to predict the stress relaxation data of these starches well (R2 > 0.98). The elastic modulus of lentil starch gel was less frequency dependent and higher in magnitude at high temperature (60 °C) than at lower temperature (10 °C). Lentil starch is suitable where higher gel strengthened pasting viscosity are desired. © 2012 Elsevier Ltd.
- Description: 2003011035
Comparative study of denaturation of whey protein isolate (WPI) in convective air drying and isothermal heat treatment processes
- Authors: Haque, M. Amdadul , Aldred, Peter , Chen, Jie , Barrow, Colin , Adhikari, Benu
- Date: 2013
- Type: Text , Journal article
- Relation: Food Chemistry Vol. 141, no. 2 (2013), p. 702-711
- Full Text: false
- Reviewed:
- Description: The extent and nature of denaturation of whey protein isolate (WPI) in convective air drying environments was measured and analysed using single droplet drying. A custom-built, single droplet drying instrument was used for this purpose. Single droplets having 5. ±. 0.1. μl volume (initial droplet diameter 1.5. ±. 0.1. mm) containing 10% (w/v) WPI were dried at air temperatures of 45, 65 and 80. °C for 600. s at constant air velocity of 0.5. m/s. The extent and nature of denaturation of WPI in isothermal heat treatment processes was measured at 65 and 80. °C for 600. s and compared with those obtained from convective air drying. The extent of denaturation of WPI in a high hydrostatic pressure environment (600. MPa for 600. s) was also determined. The results showed that at the end of 600. s of convective drying at 65. °C the denaturation of WPI was 68.3%, while it was only 10.8% during isothermal heat treatment at the same medium temperature. When the medium temperature was maintained at 80. °C, the denaturation loss of WPI was 90.0% and 68.7% during isothermal heat treatment and convective drying, respectively. The bovine serum albumin (BSA) fraction of WPI was found to be more stable in the convective drying conditions than
- Description: 2003011092
Interfacial and emulsifying properties of lentil protein isolate
- Authors: Joshi, Matina , Adhikari, Benu , Aldred, Peter , Panozzo, Joe , Kasapis, Stefan , Barrow, Colin
- Date: 2012
- Type: Text , Journal article
- Relation: Food Chemistry Vol.134 no.3 (2012), p.343-1353
- Full Text:
- Reviewed:
- Description: The dynamic interfacial tension (DIFT) at oil-water interface, diffusion coefficients, surface hydrophobicity, zeta potential and emulsifying properties, including emulsion activity index (EAI), emulsion stability index (ESI) and droplet size of lentil protein isolate (LPI), were measured at different pH and LPI concentration, in order to elucidate its emulsifying behaviour. Sodium caseinate (NaCas), whey protein isolate (WPI), bovine serum albumin (BSA) and lysozyme (Lys) were used as benchmark proteins and their emulsifying property was compared with that of LPI. The speed of diffusion-controlled migration of these proteins to the oil/water interface, was in the following order: NaCas > LPI > WPI > BSA > Lys, while their surface hydrophobicity was in the following order: BSA > LPI > NaCas > WPI > Lys. The EAI of emulsions stabilised by the above proteins ranged from 90.3 to 123.3 m 2/g and it was 93.3 ± 0.2 m 2/g in LPI-stabilised emulsion. However, the stability of LPI-stabilised emulsions was slightly lower compared to that of WPI and NaCas-stabilised emulsions at the same protein concentration at pH 7.0. The ESI of LPI emulsions improved substantially with decrease in droplet size when protein concentration was increased (20-30 mg/ml). Reduction of disulphide bonds enhanced both the EAI and ESI compared to untreated samples. Heat treatment of LPI dispersions resulted in poor emulsion stability due to molecular aggregation. The stability of LPI-stabilised emulsions was found to decrease in the presence of NaCl. This study showed that LPI can be as effective emulsifiers of oil-in-water emulsions as are WPI and NaCas at ≥20 mg/ml concentrations both at low and neutral pH. The emulsifying property of LPI can be improved by reducing the intra and inter-disulphide bond by using appropriate reducing agents. © 2012 Elsevier Ltd. All rights reserved.
Drying and denaturation characteristics of α-LACTALBUMIN, β-lactoglobulin, and bovine serum albumin in a convective drying process
- Authors: Haque, M. Amdadul , Aldred, Peter , Chen, Jie , Barrow, Colin , Adhikari, Benu
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Agricultural and Food Chemistry Vol. 62, no. 20 (2014), p. 4695-4706
- Full Text: false
- Reviewed:
- Description: Drying and denaturation kinetics of aqueous droplets of α-lactalbumin (α-lac), β-lactoglobulin (β-lg), and bovine serum albumin (BSA) were measured in a convective drying environment. Single droplets having an initial droplet diameter of 2 ± 0.1 mm and containing 10% (w/v) protein concentration were dried using conditioned air (65 and 80 °C, 2-3% RH, 0.5 m/s velocity) for 600 s. The denaturation of these proteins was measured by using reversed-phase HPLC. At the end of 600 s of drying 13.3 and 19.4% α-lac was found to be lost due to denaturation at 65 and 80 °C, respectively. Up to 31.0% of β-lg was found to be denatured, whereas BSA was not found to be significantly (p > 0.05) denatured in these drying conditions. The formation and strength of skin and the associated morphological features were found to be linked with the degree of denaturation of these proteins. The secondary structure of these proteins was significantly (p < 0.05) affected and altered by the drying stresses. The β-sheet and random coil contents were increased in α-lac by 6.5 and 4.0%, respectively, whereas the α-helix and β-turn contents decreased by 5.5 and 5.0%, respectively. The β-sheet and random coil contents in β-lg were increased by 7.5 and 2.0%, respectively, whereas the α-helix and β-turn contents decreased by 3.5 and 6.0%, respectively. In the case of BSA the β-sheet, α-helix, and random coil contents were found to increase, whereas the β-turn content decreased. © 2014 American Chemical Society.
Denaturation and physical characteristics of spray-dried whey protein isolate powders produced in the presence and absence of Lactose, Trehalose, and Polysorbate-80
- Authors: Haque, M. Amdadul , Chen, Jie , Aldred, Peter , Adhikari, Benu
- Date: 2015
- Type: Text , Journal article
- Relation: Drying Technology Vol. 33, no. 10 (2015), p. 1243-1254
- Full Text: false
- Reviewed:
- Description: The denaturation (loss of protein through aggregation and/or change in secondary structure) and physical characteristics such as powder morphology, particle size and size distribution, amorphous/crystalline behavior, and solubility of whey protein isolate (WPI) were investigated in a spray-drying process. The protective efficacy of sugars (lactose and trehalose) and low-molecular-weight surfactant polysorbate-80 (Tween-80) on the secondary structure (-turn, -sheet and -helix) and physical characteristics of spray-dried WPI was quantified. The WPI, WPI+sugar, and WPI+Tween-80 formulations were spray dried maintaining the total solids at 10% (w/w). The inlet and outlet temperatures were maintained at 180 and 80 degrees C, respectively. The results showed that the loss of protein through denaturation and aggregation was not significant (p>0.05). However, a significant (p<0.05) alteration of the secondary structural elements was observed. Due to spray drying of WPI without protectants, the -sheet and -turn were decreased by 4.4 and 14.5%, respectively, and the random coil increased by 20.7%. The -helix of WPI remained unaltered during the spray-drying process. The presence of Tween-80 effectively protected the -helix and -sheet but the -turn remained vulnerable and was decreased. No significant (p>0.05) change in the solubility of WPI was observed due to spray drying. Spray drying of WPI+sugar produced essentially amorphous particles. The dried powder particles were spherical with wrinkled or folded surface.