Barley (1 -> 3; 1 -> 4)-beta-glucan and arabinoxylan content are related to kernel hardness and water uptake
- Authors: Gamlath, Jayantha , Aldred, Peter , Panozzo, Joe
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of Cereal Science Vol. 47, no. 2 (Mar 2008), p. 365-371
- Full Text: false
- Reviewed:
- Description: Harder kernels in barley are thought to be a factor affecting the modification of the endosperm during malting by restricting water and enzyme movement within the endosperm. The objective of this study was to investigate the relationship between kernel hardness, water uptake and the endosperm composition in barley. A range of barley samples from 2003 and 2004 crops were analyzed for kernel hardness by the Single Kernel Characterization System, water uptake during steeping and chemical composition of the endosperm including (1→3; 1→4)-
- Description: C1
Blackpoint assessment of wheat using digital image analysis
- Authors: Armstrong, Bruce , Weiss, M. , Armstrong, T.A. , Greig, Robert , Aldred, Peter
- Date: 2004
- Type: Text , Conference paper
- Relation: Paper presented at 54th Australian Cereal Chemistry Conference & 11th Wheat Breeders Assembly, Canberra : 21st September, 2004
- Full Text: false
- Reviewed:
- Description: E1
- Description: 2003000817
Blackpoint impact model for wheat
- Authors: Armstrong, Bruce , Weiss, M. , Armstrong, T.A. , Aldred, Peter
- Date: 2006
- Type: Text , Conference paper
- Relation: Proceedings of the 56th Australian Cereal Chemistry Conference, Fremantle p. 110-115
- Full Text:
- Description: 2003006920
Brewers and vintners beware!: Mitigation of the carbon dioxide hazard in the fermentation industries using hierarchy of control methodology
- Authors: Young, Stephen , Naiker, Mani , Aldred, Peter
- Date: 2015
- Type: Text , Journal article
- Relation: Journal of Health, Safety and Environment Vol. 31, no. 3 (2015), p.
- Full Text: false
- Reviewed:
- Description: This paper suggests that elevated levels of CO2 are a widely underestimated occupational hazard for those working in the fermentation industries. The generation of CO2 as a natural by-product of fermentation, and the input of additional CO2, are examined and the potential CO2 hazard highlighted. The need for the rapidly growing fermentation industries to understand and mitigate this hazard is emphasised. A robust application of hierarchy of controls methodology is employed to effect a bestpractice mitigation of the CO2 hazard. The paper concludes with a strong recommendation for the use of automated monitoring linked to lock out mechanisms as the most effective means of assuring worker safety with respect to elevated levels of CO2 in the workplace. © CCH.
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
Concentration of metals in selected ANZ beers using ICP spectroscopy
- Authors: Koroznikova, Larissa , Karbanenco, Shelley , Aldred, Peter , Razavi, Kamal Seyed
- Date: 2016
- Type: Text , Conference paper
- Relation: International Symposium on Life Science & Biological Engineering
- Full Text: false
- Reviewed:
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.
Detecting rice discoloration with an image analyser
- Authors: Armstrong, Bruce , Blakeney, A.B. , Armstrong, T.A. , Aldred, Peter
- Date: 2007
- Type: Text , Conference proceedings
- Full Text: false
- Description: 2003005465
Determining screening fractions and kernel roundness with digital image analysis
- Authors: Armstrong, Bruce , Weiss, M. , Greig, Robert , Dines, J. , Gooden, J. , Aldred, Peter
- Date: 2003
- Type: Text , Conference paper
- Relation: Proceedings of the 53rd Australian Cereal Chemistry Conference , Adelaide
- Full Text: false
- Description: 2003006917
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.
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.
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
Growth and survival of foodborne pathogens in beer
- Authors: Menz, Garry , Aldred, Peter , Vriesekoop, Frank
- Date: 2011
- Type: Text , Journal article
- Relation: Journal of Food Protection Vol. 74, no. 10 (2011), p. 1670-1675
- Full Text: false
- Reviewed:
- Description: This work aimed to assess the growth and survival of four foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus) in beer. The effects of ethanol, pH, and storage temperature were investigated for the gram-negative pathogens (E. coli O157:H7 and Salmonella Typhimurium), whereas the presence of hops ensured that the gram-positive pathogens (L. monocytogenes and S. aureus) were rapidly inactivated in alcohol-free beer. The pathogens E. coli O157:H7 and Salmonella Typhimurium could not grow in the mid-strength or full-strength beers, although they could survive for more than 30 days in the mid-strength beer when held at 4°C. These pathogens grew rapidly in the alcoholfree beer; however, growth was prevented when the pH of the alcohol-free beer was lowered from the "as received" value of 4.3 to 4.0. Pathogen survival in all beers was prolonged at lowered storage temperatures. Copyright © International Association for Food Protection.
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.
Is that the light at the end of the tunnel, or is it an oncoming train? : An obsession with obvious workplace hazards may blind us to approaching catastrophe
- Authors: Young, Stephen , Blitvich, Jennifer , Naiker, Mani , Aldred, Peter
- Date: 2017
- Type: Text , Journal article , Review
- Relation: Journal of Health, Safety and Environment Vol. 33, no. 1 (2017), p. 1-17
- Full Text: false
- Reviewed:
- Description: A mixed method survey of owners of commercial breweries in Victoria and Tasmania (Australia) was conducted (n = 45). The purpose of the study was to gain an understanding of how the breweries mitigated for the hazards they identified - in particular, asphyxiation from elevated levels of CO 2 . The survey comprised a questionnaire regarding the breweries' age, staff numbers, how brewery owners assessed a 'significant' hazard, and their methods of recognition and mitigation of the CO 2 hazard. The research methodology also encouraged and recorded qualitative responses. The research intended to gain an understanding of how the breweries mitigated for the hazards they identified - in particular, asphyxiation from elevated levels of CO 2 . Contradictions between the respondents' questionnaire (quantitative) and qualitative responses were noted. A discontinuity between the respondents' awareness of potential Class I injuries and their safety processes was discussed - in particular, the distinction between high frequency and high consequence hazards. Accordingly, the paper suggests a "polar area" graph for mapping hazards in small businesses generally, to highlight rare but potentially catastrophic injuries among known industry hazards. © CCH.
Isolation, identification, and characterisation of beer-spoilage lactic acid bacteria from microbrewed beer from Victoria, Australia
- Authors: Menz, Garry , Andrighetto, Christian , Lombardi, Angiolella , Corich, Viviana , Aldred, Peter , Vriesekoop, Frank
- Date: 2010
- Type: Text , Journal article
- Relation: Journal of the Institute of Brewing Vol. 116, no. 1 (2010), p. 14-22
- Full Text: false
- Reviewed:
- Description: Lactic acid bacteria are the most frequently encountered beer-spoilage bacteria, and they may render beer undrinkable due to the production of lactic acid, diacetyl, and turbidity. Micro-brewed beer is typically sold unpasteurised, leaving it more susceptible to spoilage by lactic acid bacteria. In this study, the incidence of lactic acid bacteria in bottled microbrewed beer from Victoria, Australia was investigated. A total of 80 beers from 19 breweries were screened for lactic acid bacteria. Almost 30% contained culturable lactic acid bacteria, and many had lactic acid levels well above the flavour threshold. Ethanol, hops, and the pH levels of the beers were not predictors for spoilage in the beers examined, and contamination appeared to be more closely linked to the source brewery. The 45 lactic acid strains isolated from these beers were identified by RAPD-PCR, with Lactobacillus brevis being the most frequently isolated species. All isolates were capable of spoiling beer and contained putative hop resistance genes. At typical beer levels, pH and ethanol had no effect on the growth of the particular spoilage bacteria isolated in this study. © 2010 The Institute of Brewing & Distilling.
- Description: 2003008145
Measuring long grain rice with an image analyser
- Authors: Armstrong, Bruce , Armstrong, T.A. , Blakeney, A.B. , Lewin, L.G. , Aldred, Peter
- Date: 2006
- Type: Text , Conference paper
- Relation: Proceedings of the 56th Australian Cereal Chemistry Conference , Fremantle p. 277-282
- Full Text:
- Description: 2003005465
Measuring rice grain dimensions with an flat bed image analyser
- Authors: Armstrong, Bruce , Armstrong, T.A. , Blakeney, A.B. , Lewin, L.G. , Aldred, Peter
- Date: 2005
- Type: Text , Conference paper
- Relation: Cereals 2005: Proceedings of the 55th Australian Cereal Chemistry Conference ,
- Full Text: false
- Description: 2003005471
Pathogens in Beer
- Authors: Menz, Garry , Aldred, Peter , Vriesekoop, Frank
- Date: 2009
- Type: Text , Book chapter
- Relation: Beer in Health and Disease Prevention Chapter p. 403-413
- Full Text: false
- Reviewed:
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