This page has only limited features, please log in for full access.
Based on unsteady state heat conduction, a mathematical model has been developed to describe the simultaneous heat and moisture transfer during potato frying. For the first time, the equation was solved using both enthalpy and Variable Space Network (VSN) methods, based on a moving interface defined by the boiling temperature of water in a potato disc during frying. Two separate regions of the potato disc namely fried (crust) and unfried (core), were considered as heat transfer domains. A variable boiling temperature of the water in potato discs was required as an input parameter for the model as the water is evaporated during frying, resulting in an increase in the soluble solid concentration of the potato sample. Pulsed electric field (PEF) pretreatment prior to frying had no significant effect on the measured moisture content, thermal conductivity or frying time compared to potatoes that did not receive a PEF pretreatment. However, a PEF pretreatment at 1.1 kV/cm and 56 kJ/kg reduced the temperature variation in the experimentally measured potato center by up to 30%. The proposed heat and moisture transfer model based on unsteady state heat conduction successfully predicted the experimental measurements, especially when the equation was solved using the enthalpy method.
Gohar Gholamibozanjani; Sze Leong; Indrawati Oey; Phil Bremer; Patrick Silcock; Mohammed Farid. Heat and Mass Transfer Modeling to Predict Temperature Distribution during Potato Frying after Pre-Treatment with Pulsed Electric Field. Foods 2021, 10, 1679 .
AMA StyleGohar Gholamibozanjani, Sze Leong, Indrawati Oey, Phil Bremer, Patrick Silcock, Mohammed Farid. Heat and Mass Transfer Modeling to Predict Temperature Distribution during Potato Frying after Pre-Treatment with Pulsed Electric Field. Foods. 2021; 10 (8):1679.
Chicago/Turabian StyleGohar Gholamibozanjani; Sze Leong; Indrawati Oey; Phil Bremer; Patrick Silcock; Mohammed Farid. 2021. "Heat and Mass Transfer Modeling to Predict Temperature Distribution during Potato Frying after Pre-Treatment with Pulsed Electric Field." Foods 10, no. 8: 1679.
This study assessed if Chinese consumer attitudes towards a range of lamb attributes (such as origin, food safety, appearance, taste, price), and their opinions of New Zealand lamb (9- and 7-point Likert scales, respectively), had changed since the outbreak COVID-19. The same survey was carried out in Shanghai and Beijing pre (December 2018) and post COVID-19 (November 2020), ~9 months after China’s initial outbreak, with 500 and 523 consumers, respectively. From December 2018 to November 2020, there was an increase in the proportion of Chinese consumers purchasing red meat online or from a butcher, and cooking their lamb well-done. In contrast, there were minimal differences in Chinese consumer ratings between December 2018 and November 2020 for different lamb attributes and opinions of New Zealand lamb. Cluster analysis revealed that many consumers (140 in December 2018/376 in November 2020) used only a small portion of the high end of the scale when rating lamb attributes, resulting in little differences between the attributes. This study suggests COVID-19 has enhanced some food safety related behaviors but had little effect on Chinese opinions and preferences for New Zealand lamb attributes. It also highlights that survey design should be carefully considered when collecting responses from Chinese consumers.
Scott Hutchings; Luis Guerrero; Miranda Mirosa; Phil Bremer; Damien Mather; Enrique Pavan; Talia Hicks; Li Day; Carolina Realini. The Implications of COVID-19 on Chinese Consumer Preferences for Lamb Meat. Foods 2021, 10, 1324 .
AMA StyleScott Hutchings, Luis Guerrero, Miranda Mirosa, Phil Bremer, Damien Mather, Enrique Pavan, Talia Hicks, Li Day, Carolina Realini. The Implications of COVID-19 on Chinese Consumer Preferences for Lamb Meat. Foods. 2021; 10 (6):1324.
Chicago/Turabian StyleScott Hutchings; Luis Guerrero; Miranda Mirosa; Phil Bremer; Damien Mather; Enrique Pavan; Talia Hicks; Li Day; Carolina Realini. 2021. "The Implications of COVID-19 on Chinese Consumer Preferences for Lamb Meat." Foods 10, no. 6: 1324.
In the midst of the global 2020 COVID-19 outbreak, the advantages of online food delivery (FD) were obvious as it facilitated consumer access to prepared meals and enabled food providers to keep operating. However, online FD is not without its critics, with reports of consumer and restaurant boycotts. It is therefore time to take stock and consider the broader impacts of online FD and what they mean for the stakeholders involved. Using the three pillars of sustainability as a lens through which to consider the impacts, this review presents the most up-to-date research in this field revealing a raft of positive and negative impacts. From an economic standpoint, online FD while providing job and sale opportunities has been criticized for high commissions it charges restaurants and questionable working conditions for delivery people. From a social perspective, online FD is affecting the relationship between consumers and their food as well as influencing public health outcomes and traffic systems. Environmental impacts include the generation of worrying amounts of waste and its high carbon footprints. Stakeholders must consider how best to mitigate the negative and promote the positive impacts of online FD to ensure that it is sustainable, in every sense, moving forward.
Charlene Li; Miranda Mirosa; Phil Bremer. Online Food Delivery Platforms. 2020, 1 .
AMA StyleCharlene Li, Miranda Mirosa, Phil Bremer. Online Food Delivery Platforms. . 2020; ():1.
Chicago/Turabian StyleCharlene Li; Miranda Mirosa; Phil Bremer. 2020. "Online Food Delivery Platforms." , no. : 1.
Deep-fried foods (e.g., French fries, potato/veggie crisps) are popular among consumers. Recently, there has been an increased interest in the application of Pulsed Electric Fields (PEF) technology as a pretreatment of plant-based foods prior to deep-frying to improve quality (e.g., lower browning tendency and oil uptake) and reduce production costs (e.g., better water and energy efficiencies). However, the influence of a PEF pretreatment on the frying process and related chemical reactions for food materials is still not fully understood. PEF treatment of plant tissue causes structural modifications, which are likely to influence heat, mass and momentum transfers, as well as altering the rate of chemical reactions, during the frying process. Detailed insights into the frying process in terms of heat, mass (water and oil) and momentum transfers are outlined, in conjunction with the development of Maillard reaction and starch gelatinisation during frying. These changes occur during frying and consequently will impact on oil uptake, moisture content, colour, texture and the amount of contaminants in the fried foods, as well as the fried oil, and hence, the effects of PEF pretreatment on these quality properties of a variety of fried plant-based foods are summarised. Different mathematical models to potentially describe the influence of PEF on the frying process of plant-based foods and to predict the quality parameters of fried foods produced from PEF-treated plant materials are addressed.
Zihan Xu; Sze Ying Leong; Mohammed Farid; Patrick Silcock; Phil Bremer; Indrawati Oey. Understanding the Frying Process of Plant-Based Foods Pretreated with Pulsed Electric Fields Using Frying Models. Foods 2020, 9, 949 .
AMA StyleZihan Xu, Sze Ying Leong, Mohammed Farid, Patrick Silcock, Phil Bremer, Indrawati Oey. Understanding the Frying Process of Plant-Based Foods Pretreated with Pulsed Electric Fields Using Frying Models. Foods. 2020; 9 (7):949.
Chicago/Turabian StyleZihan Xu; Sze Ying Leong; Mohammed Farid; Patrick Silcock; Phil Bremer; Indrawati Oey. 2020. "Understanding the Frying Process of Plant-Based Foods Pretreated with Pulsed Electric Fields Using Frying Models." Foods 9, no. 7: 949.
During the global 2020 COVID-19 outbreak, the advantages of online food delivery (FD) were obvious, as it facilitated consumer access to prepared meals and enabled food providers to keep operating. However, online FD is not without its critics, with reports of consumer and restaurant boycotts. It is, therefore, time to take stock and consider the broader impacts of online FD, and what they mean for the stakeholders involved. Using the three pillars of sustainability as a lens through which to consider the impacts, this review presents the most up-to-date research in this field, revealing a raft of positive and negative impacts. From an economic standpoint, while online FD provides job and sale opportunities, it has been criticized for the high commission it charges restaurants and questionable working conditions for delivery people. From a social perspective, online FD affects the relationship between consumers and their food, as well as influencing public health outcomes and traffic systems. Environmental impacts include the significant generation of waste and its high carbon footprints. Moving forward, stakeholders must consider how best to mitigate the negative and promote the positive impacts of online FD to ensure that it is sustainable in every sense.
Charlene Li; Miranda Mirosa; Phil Bremer. Review of Online Food Delivery Platforms and their Impacts on Sustainability. Sustainability 2020, 12, 5528 .
AMA StyleCharlene Li, Miranda Mirosa, Phil Bremer. Review of Online Food Delivery Platforms and their Impacts on Sustainability. Sustainability. 2020; 12 (14):5528.
Chicago/Turabian StyleCharlene Li; Miranda Mirosa; Phil Bremer. 2020. "Review of Online Food Delivery Platforms and their Impacts on Sustainability." Sustainability 12, no. 14: 5528.
This paper investigated Vietnamese consumers’ preferences for functional milk powder products to determine if there were differences in market segments. A Qualtrics survey and a 1000minds choice-based conjoint survey were completed by 272 participants, predominantly 18-30-year-old males with high education levels and above average incomes. Firstly, general perceptions of the use of functional foods to maintain health were determined, with results revealing that participants believed in the benefits the foods claim to provide. Secondly, participants’ tradeoffs for specific extrinsic functional milk powder attributes were determined by examining the relative importance they placed on a range of attributes. Participants prioritized a quality stamp attribute and preferred that this was obtained from an international certification body. Finally, a two-step cluster analysis and multinomial logistic regression was used to profile the participants and analyze relationships between socio-demographic data and the four resulting segments (i.e., Food Safety Concerned, Price Sensitive, Premium Product Focused, and Nutrition Focused). The largest of these segments was Food Safety Concerned (46.3%) with males significantly less likely than females to be in this segment. Given the limited literature on Vietnamese consumers’ decision-making processes, this study is an important contribution to this topic, as well as providing information about market opportunities.
Trong Phan; Phil Bremer; Miranda Mirosa. Vietnamese Consumers’ Preferences for Functional Milk Powder Attributes: A Segmentation-Based Conjoint Study with Educated Consumers. Sustainability 2020, 12, 5258 .
AMA StyleTrong Phan, Phil Bremer, Miranda Mirosa. Vietnamese Consumers’ Preferences for Functional Milk Powder Attributes: A Segmentation-Based Conjoint Study with Educated Consumers. Sustainability. 2020; 12 (13):5258.
Chicago/Turabian StyleTrong Phan; Phil Bremer; Miranda Mirosa. 2020. "Vietnamese Consumers’ Preferences for Functional Milk Powder Attributes: A Segmentation-Based Conjoint Study with Educated Consumers." Sustainability 12, no. 13: 5258.
This study investigated how Chinese consumers prioritize cues when assessing the safety of imported milk powder. A choice-based conjoint survey was completed by 307 participants in Beijing, Shanghai, Tianjin, and Nanjing, using the internet-based software 1000minds. Important cues for consumers were “government certification logo shown on the product label/Website”; “ingredients and materials, free from preservatives and additives”; “having traceability techniques such as QR code included” and “realistic photos.” Distinct consumer segments reflecting differing trade-offs between safety cues were not detected suggesting that a single food safety communication strategy for this market may be sufficient. These findings add to extant literature by highlighting what cues give consumers the most confidence a product is safe and they provide a raft of actionable insights for government and the food industry in terms of designing and implementing effective risk or market communication strategies for Chinese consumers.
Miranda Mirosa; Yang Liu; Phil Bremer. Determining How Chinese Consumers that Purchase Western Food Products Prioritize Food Safety Cues: A Conjoint Study on Adult Milk Powder. Journal of Food Products Marketing 2020, 26, 358 -371.
AMA StyleMiranda Mirosa, Yang Liu, Phil Bremer. Determining How Chinese Consumers that Purchase Western Food Products Prioritize Food Safety Cues: A Conjoint Study on Adult Milk Powder. Journal of Food Products Marketing. 2020; 26 (5):358-371.
Chicago/Turabian StyleMiranda Mirosa; Yang Liu; Phil Bremer. 2020. "Determining How Chinese Consumers that Purchase Western Food Products Prioritize Food Safety Cues: A Conjoint Study on Adult Milk Powder." Journal of Food Products Marketing 26, no. 5: 358-371.
Bacillus cereus spores pose a challenge to the food industry owing to their ability to germinate in food during storage and produce toxins. The objective of the current study was to investigate the effect of pulsed electric field (PEF) at low electric field strength (i.e., 7.3, 8.1, 8.8 and 9.4 kV/cm) and moderate temperatures (65, 70, 75 and 80°C) on B. cereus spores. PEF treatment at 9.4 kV/cm at 80°C (pulse width of 20 μs and frequency of 300 Hz) led to a 3.1 log CFU/ml reduction in the number of B. cereus spores and importantly, the D88°C values of the surviving spores were reduced by 12 min. Differential gene expression revealed the upregulation of the gene (BC1768) encoding for chitooligosaccharide deacetylase involved in peptidoglycan degradation in PEF treated spores. The gene (BC2729) encoding for a penicillin‐binding protein required for septation during sporulation was downregulated in PEF treated spores. Practical applications PEF treatment is an emerging food processing technology that has gained attention owing to its potential to provide high‐quality foods. However, to date the inactivation of bacterial spores by PEF has only been partially successful and then only when combined with high heat. The effect of PEF on the thermal stability of spores has not previously been reported. The current work bridges these gaps by providing insight into differential gene expression associated with the PEF treatment of B. cereus spores. The study indicates the potential for PEF to be incorporated into a hurdle regime targeting spore inactivation and provides data on specific genes that may help to provide a better understanding of the stress induced in B. cereus spores by PEF treatment.
Aswathi Soni; Indrawati Oey; Patrick Silcock; Ian K. Ross; Phil J. Bremer. Effect of pulsed electric field with moderate heat (80°C) on inactivation, thermal resistance and differential gene expression inB. cereusspores. Journal of Food Processing and Preservation 2020, 44, 1 .
AMA StyleAswathi Soni, Indrawati Oey, Patrick Silcock, Ian K. Ross, Phil J. Bremer. Effect of pulsed electric field with moderate heat (80°C) on inactivation, thermal resistance and differential gene expression inB. cereusspores. Journal of Food Processing and Preservation. 2020; 44 (7):1.
Chicago/Turabian StyleAswathi Soni; Indrawati Oey; Patrick Silcock; Ian K. Ross; Phil J. Bremer. 2020. "Effect of pulsed electric field with moderate heat (80°C) on inactivation, thermal resistance and differential gene expression inB. cereusspores." Journal of Food Processing and Preservation 44, no. 7: 1.
Air pollution is becoming an increasing problem in many developing economies with China being one of the countries most effected. Four Consumer Idealized Design (CID) workshops were conducted in Suzhou to explore the ideal product attributes consumers require in functional foods designed to combat the adverse impact of air pollution. A tablet was the most common format in the supplement designs and the majority of conventional-foods were designed as either snacks, drinks, or dairy options. Effective health claims were considered to be “boosting immunity” for products designed for long-term use and “relieving respiratory symptoms” for products designed for use in acute situations. Supplements and conventional-format functional foods were perceived as having different health benefits and target markets. Consumers’ attention to food safety suggested product producers should apply multi-methods to communicate the safety of their products to consumers. This study was the first to utilize CID workshops with Chinese consumers and will help inform industry product development.
Lei Cong; Miranda Mirosa; William Kaye-Blake; Phil Bremer. Ideal Attributes of Functional Foods Helping the Immune System Recover From the Impact of Air Pollution: A Consumer-Led Product Design. Journal of International Food & Agribusiness Marketing 2020, 32, 482 -502.
AMA StyleLei Cong, Miranda Mirosa, William Kaye-Blake, Phil Bremer. Ideal Attributes of Functional Foods Helping the Immune System Recover From the Impact of Air Pollution: A Consumer-Led Product Design. Journal of International Food & Agribusiness Marketing. 2020; 32 (5):482-502.
Chicago/Turabian StyleLei Cong; Miranda Mirosa; William Kaye-Blake; Phil Bremer. 2020. "Ideal Attributes of Functional Foods Helping the Immune System Recover From the Impact of Air Pollution: A Consumer-Led Product Design." Journal of International Food & Agribusiness Marketing 32, no. 5: 482-502.
Functional beverages have gained increasing market share over the last decade. As the Asia Pacific region is one of the largest and most important markets for functional foods, it is critical when developing and promoting new products that food manufacturers/marketers have a good understanding of the Asia Pacific market, including the legislative requirements and consumers’ perceptions of functional beverages. A literature review was undertaken to elucidate legislation criteria and consumers’ perceptions of functional beverages in Asia Pacific countries. Topics reviewed included the origin and definitions of functional foods and beverages; the legislative criteria for functional foods and beverages in four representative countries—Australia, New Zealand, China, and Japan; and consumers’ perceptions of functional beverages. There was no concrete definition of “functional food” or “functional beverage” region-wide and correspondingly, the legislative terms and regulatory frameworks for functional foods and beverages varied from country to country and showed divergence due to cultural differences. The systematic review of consumer perceptions of functional beverages showed that product acceptance and purchase intention for different functional beverages was heterogeneous among consumers in the Asian Pacific Region, with many factors playing a role including product attributes (e.g., functional attributes, sensory attributes, and product form) and consumer perceptions (e.g., health motivation, trust in food industry, and food neophobia). The findings from this review will help guide product development and inform marketing strategies for functional beverages targeting the Asia Pacific region by providing information on legislation and consumers’ perceptions.
Lei Cong; Phil Bremer; Miranda Mirosa. Functional Beverages in Selected Countries of Asia Pacific Region: A Review. Beverages 2020, 6, 21 .
AMA StyleLei Cong, Phil Bremer, Miranda Mirosa. Functional Beverages in Selected Countries of Asia Pacific Region: A Review. Beverages. 2020; 6 (2):21.
Chicago/Turabian StyleLei Cong; Phil Bremer; Miranda Mirosa. 2020. "Functional Beverages in Selected Countries of Asia Pacific Region: A Review." Beverages 6, no. 2: 21.
The deterioration of air quality in China has resulted in many people looking for remedies to counteract the impact that air pollution is perceived to be having on their health. As the importance of diet on immune health is becoming increasingly well recognised, a narrative literature review was undertaken to elucidate Chinese consumers’ acceptance of functional food products designed to help the immune system recover from pollution-driven impact and to assess their market potential. Consumers’ attitude towards immune-boosting functional foods were mainly positive, with scientific validation being important in determining the credibility of a product. This was despite the fact that the effectiveness of the functional food products currently in the market that purported to be remedies for pollution-driven impacts on the lung did not appear to be supported by scientific evidence. Numerous studies have reported functional foods could provide a wide range of benefits to immune health, including helping pollution-driven immune issues. This review highlights the market demand for effective and scientifically-proven functional food products that help Chinese consumers’ immune system recover from the impact of air pollution.
Lei Cong; Miranda Mirosa; William Kaye-Blake; Phil Bremer. Immune-Boosting Functional Foods: A Potential Remedy for Chinese Consumers Living Under Polluted Air. Business and Management Studies 2020, 6, 12 -27.
AMA StyleLei Cong, Miranda Mirosa, William Kaye-Blake, Phil Bremer. Immune-Boosting Functional Foods: A Potential Remedy for Chinese Consumers Living Under Polluted Air. Business and Management Studies. 2020; 6 (1):12-27.
Chicago/Turabian StyleLei Cong; Miranda Mirosa; William Kaye-Blake; Phil Bremer. 2020. "Immune-Boosting Functional Foods: A Potential Remedy for Chinese Consumers Living Under Polluted Air." Business and Management Studies 6, no. 1: 12-27.
Recent growth and diversification of sheep milk products means more sophisticated methods are required to ensure their flavour quality. The objective of this study was to compare four extraction techniques for the analysis of volatile compounds in sheep milk by gas chromatography-mass spectrometry (GC-MS). Solvent Assisted Flavour Evaporation (SAFE), Solid Phase Microextraction (SPME), Headspace Sorptive Extraction (HSSE) and Stir Bar Sorptive Extraction (SBSE) were evaluated for their sensitivity, selectivity, reproducibility, and overall efficiency. A total of 48 volatile compounds from nine compound classes were identified in the spray-dried sheep milk. Alcohols, aldehydes, alkanes, carboxylic acids, ketones, lactones, sulphur compounds, nitrogen compounds, and terpenes were all present, but the differences between the methods were most apparent for lactones. SBSE extracted eight lactones, SAFE extracted four lactones and HSSE and SPME only detected trace levels of two lactones. Six of the lactones-δ-hexa-lactone, δ-octalactone, γ-decalactone, γ-dodecalactone, δ-tetradecalactone, and δ-hexadeca-lactone-were identified for the first time in spray-dried sheep milk. The present work demonstrated that SBSE is an effective tool for the extraction and analysis of volatiles, especially lactones, in sheep milk and dairy products in general. A discussion of the benefits and limitations of each method is included.
Ryan High; Phil Bremer; Biniam Kebede; Graham T. Eyres. Comparison of Four Extraction Techniques for the Evaluation of Volatile Compounds in Spray-Dried New Zealand Sheep Milk. Molecules 2019, 24, 1917 .
AMA StyleRyan High, Phil Bremer, Biniam Kebede, Graham T. Eyres. Comparison of Four Extraction Techniques for the Evaluation of Volatile Compounds in Spray-Dried New Zealand Sheep Milk. Molecules. 2019; 24 (10):1917.
Chicago/Turabian StyleRyan High; Phil Bremer; Biniam Kebede; Graham T. Eyres. 2019. "Comparison of Four Extraction Techniques for the Evaluation of Volatile Compounds in Spray-Dried New Zealand Sheep Milk." Molecules 24, no. 10: 1917.
The effect of pulsed electric fields (0.7 and 1.5 kV/cm, specific energy 90–100 kJ/kg) processing followed by post–pulsed electric field (PEF) ageing ( 0, 3, 7, 14 days) on the safety and quality attributes of sous vide–processed (60 °C/12 or 24 h) beef briskets was assessed. Ageing did not significantly reduce the hardness of sous vide–processed meat except for those PEF treated either at 0.7 kV/cm followed by sous vide processing for 12 h or at 1.5 kV/cm followed by sous vide processing for 24 h. Post-PEF ageing time had no effect on the collagen solubility of sous vide–processed meat. The effect of PEF treatment on hardness was much greater than the effect of ageing time, and sous vide processing time. Sous vide processing (12 or 24 h) for all treatments reduced both aerobic and lactic acid bacteria numbers to below the detection limit. Initial peptide concentrations during in vitro peptic digestibility were significantly (P < 0.05) different between some treatments; however no significant (P > 0.05) differences were observed in digestion rates between any treatment. Ageing of PEF-treated meat for a few days prior to sous vide processing may improve tenderness; however, these gains in quality may be offset by a greater total water loss and an increase in lipid oxidation.
A. U. Alahakoon; I. Oey; P. Bremer; P. Silcock. Quality and Safety Considerations of Incorporating Post-PEF Ageing into the Pulsed Electric Fields and Sous Vide Processing Chain. Food and Bioprocess Technology 2019, 12, 852 -864.
AMA StyleA. U. Alahakoon, I. Oey, P. Bremer, P. Silcock. Quality and Safety Considerations of Incorporating Post-PEF Ageing into the Pulsed Electric Fields and Sous Vide Processing Chain. Food and Bioprocess Technology. 2019; 12 (5):852-864.
Chicago/Turabian StyleA. U. Alahakoon; I. Oey; P. Bremer; P. Silcock. 2019. "Quality and Safety Considerations of Incorporating Post-PEF Ageing into the Pulsed Electric Fields and Sous Vide Processing Chain." Food and Bioprocess Technology 12, no. 5: 852-864.
Differential gene expression was used to explore the mechanisms underpinning the differences in the impact of heat activation (70 °C for 30 min) on the germination of Bacillus cereus spores in the presence and absence of a germinant (L-alanine). The number of germinated cells, after heat activation plus L-alanine (3.5 ± 0.02 log CFU/ml) in the spore only initial population was found to be higher than that in only heat activated spores (2.01 ± 0.02 log CFU/ml). The concentration of DPA released by heat activated spores in the presence of L-alanine was 68.3 ± 0.1 and 112.1 ± 0.02 μg/ml after 30 and 60 min, compared to 96.5 and 166.2 ± 0.01 μg/ml after 30 and 90 min, respectively released by spores subjected only to heat activation. Gene (BC0784) encoding for the spore germination protein, gerA operon was up-regulated with a log2-transformed fold change value of 1.2 due to heat activation in the presence of L-alanine. The GerA operon located in the inner membrane is known to be involved in the uptake of L-alanine by B. cereus and has been reported to be involved in L-alanine mediated germination. In addition the up-regulation of genes involved in the uptake of L-alanine is proposed to provide the answer to the synergistic effect of heat and L-alanine in inducing germination in B. cereus spores. In short, heat activation increases the ability of L-alanine to penetrate into the spore's inner membrane, where it can be recognized by the receptors for initiation of the germination pathway. In the current study, the majority of the ribosomal proteins were down-regulated (when spores were heat treated in presence of germinants) this process also appeared to slow down protein synthesis by restricting the protein translation machinery. Differential gene expression revealed the genes responsible for the pathways related to transport and recognition of L-alanine into the spore that could have led to the accelerated germination process along with partial shutting down of protein synthesis pathway and ABC transporters. Knowledge of gene regulation in spores during heat activation will help in the development of approaches to prevent spore germination, which could provide an additional safeguard against bacterial growth and toxin production in improperly cooled heat treated foods.
Aswathi Soni; Indrawati Oey; Patrick Silcock; Elizabeth Permina; Phil J. Bremer. Differential gene expression for investigation of the effect of germinants and heat activation to induce germination in Bacillus cereus spores. Food Research International 2018, 119, 462 -468.
AMA StyleAswathi Soni, Indrawati Oey, Patrick Silcock, Elizabeth Permina, Phil J. Bremer. Differential gene expression for investigation of the effect of germinants and heat activation to induce germination in Bacillus cereus spores. Food Research International. 2018; 119 ():462-468.
Chicago/Turabian StyleAswathi Soni; Indrawati Oey; Patrick Silcock; Elizabeth Permina; Phil J. Bremer. 2018. "Differential gene expression for investigation of the effect of germinants and heat activation to induce germination in Bacillus cereus spores." Food Research International 119, no. : 462-468.
This study used multiple regression to model the effect of pulsed electric field (electric field strengths 0.7, 1.0 or 1.5 kV cm−1) and sous vide (60 °C for either 12, 18 or 24 h) processing on the quality parameters (tenderness, cooking loss, colour, lipid stability) of beef brisket. Pulsed electric fields (PEF) at 0.7 kV cm−1 and 1.5 kV cm−1 followed by sous vide processing for 12–20.2 and 20.8–23.7 h, respectively gave the lowest values for hardness (<20.2 N), shear force (100.5 N mm−1 s−1) and cooking loss (<17.4%). PEF treatment prior to sous vide processing had no significant effect on lipid oxidation, colour stability, cooking loss or in vitro protein digestibility of sous vide‐processed brisket. Increasing the electric field strength and/or prolonging the sous vide time significantly increased collagen solubilisation in the sous vide brisket. This study demonstrated that a PEF pre‐treatment can reduce sous vide processing time while enhancing the tenderness of tough meat cuts.
Amali U. Alahakoon; Indrawati Oey; Phil Bremer; Patrick Silcock. Process optimisation of pulsed electric fields pre‐treatment to reduce the sous vide processing time of beef briskets. International Journal of Food Science & Technology 2018, 54, 823 -834.
AMA StyleAmali U. Alahakoon, Indrawati Oey, Phil Bremer, Patrick Silcock. Process optimisation of pulsed electric fields pre‐treatment to reduce the sous vide processing time of beef briskets. International Journal of Food Science & Technology. 2018; 54 (3):823-834.
Chicago/Turabian StyleAmali U. Alahakoon; Indrawati Oey; Phil Bremer; Patrick Silcock. 2018. "Process optimisation of pulsed electric fields pre‐treatment to reduce the sous vide processing time of beef briskets." International Journal of Food Science & Technology 54, no. 3: 823-834.
The impact of different ratios of lean meat, adipose tissue (fat) and bone on the volatile organic compound (VOC) profile of vacuum-packed (VP) lamb stored at 2 °C for up to 15 days was investigated using two sampling approaches. Individual samples were followed over time using either a traditional sampling regime where replicate samples were sampled (single-use) at a given time or a novel approach where replicate samples were resampled (reuse) over time. VOCs present in the headspace of the packaged samples were detected using proton-transfer-reaction mass spectrometry (PTR-MS) with complementary solid phase micro-extraction gas chromatography–mass spectrometry (SPME-GC-MS) analysis on a subset of samples. Bacteria numbers were determined using standard microbiological methods. Meat packaged with 20% added adipose tissue contained slightly higher numbers of bacteria at the start of the trial with correspondingly higher VOC levels compared to lean meat alone. Storage time (as a proxy for microbial numbers) was the main driver for VOC production. Differences between the reuse and the single-use sample sets were minimal, suggesting that resampling of VP lamb samples may be a useful approach to study the development of low frequency spoilage patterns overtime.
Lena Schuster; Corinna Franke; Patrick Silcock; Jonathan Beauchamp; Phil J. Bremer. Development of a novel sample reuse approach to measure the impact of lean meat, bone and adipose tissue on the development of volatiles in vacuum-packed chilled lamb stored at 2 °C for 15 days. Meat Science 2018, 145, 31 -39.
AMA StyleLena Schuster, Corinna Franke, Patrick Silcock, Jonathan Beauchamp, Phil J. Bremer. Development of a novel sample reuse approach to measure the impact of lean meat, bone and adipose tissue on the development of volatiles in vacuum-packed chilled lamb stored at 2 °C for 15 days. Meat Science. 2018; 145 ():31-39.
Chicago/Turabian StyleLena Schuster; Corinna Franke; Patrick Silcock; Jonathan Beauchamp; Phil J. Bremer. 2018. "Development of a novel sample reuse approach to measure the impact of lean meat, bone and adipose tissue on the development of volatiles in vacuum-packed chilled lamb stored at 2 °C for 15 days." Meat Science 145, no. : 31-39.
Bacillus cereus spores in food are able to survive pasteurization, and if conditions are favourable, subsequently germinate, grow and produce toxins causing food poisoning. The objectives of this study were to firstly determine the impact of cold storage and ion uptake on the thermal resistance of B. cereus spores and secondly to use differential gene expression to help elucidate possible molecular mechanisms for the changes detected in their thermal resistance. B. cereus spores were held at 4 °C in either 0.05 or 0.5 M solutions of cations (Na+, Ca2+ Mg2+,K+, Zn2+) for 6 days and their D88-values were estimated. In the presence of sodium chloride (0.05 and 0.5 M), sodium phosphate buffer, (pH 7, 0.05 and 0.5 M) or zinc acetate (0.05 M), D88 values decreased by 8.8, 10.9, 11.2, 12.9, and 10.2 min respectively, with no evidence of germination (plating methods). Exposure of spores to Na+ in sodium phosphate buffer (pH 7, 0.05 and 0.5 M) or sodium chloride (0.05 and 0.5 M) resulted in the accumulation of Na+ (66.0 ± 2.9, 193.1 ± 4.6, 136.2 ± 9.9 and 70.5 ± 2.7 μg/g) by spores at the significant expense of K+ (10.8 ± 0.5, 7.5 ± 0.2, 8.1 ± 0.4 and 3.6 ± 0.4 μg/g respectively). The mechanism behind the loss of resistance in sodium phosphate buffer (0.05 M) was further investigated by monitoring the differential gene expression using mRNA sequencing. Genes encoding for uracil permease (BC_3890), Mg2+ P-type ATPase-like protein (BC_1581), ABC transporter ATP-binding protein (BC_0815), and 2-keto-3-deoxygluconate permease (BC_4841) were significantly (FDR value ≤0.05) upregulated. This upregulation indicated a possible increase in permeability, which is suggested to account for the increased uptake of sodium ions and the reduction measured in the spore's thermal resistance. This data suggests that during storage at 4 °C in the presence of sodium ions, spores should not be considered to be completely dormant.
Aswathi Soni; Indrawati Oey; Patrick Silcock; Elizabeth Permina; Phil J. Bremer. Effect of cold storage and different ions on the thermal resistance of B. cereus NZAS01 spores- analysis of differential gene expression and ion exchange. Food Research International 2018, 116, 578 -585.
AMA StyleAswathi Soni, Indrawati Oey, Patrick Silcock, Elizabeth Permina, Phil J. Bremer. Effect of cold storage and different ions on the thermal resistance of B. cereus NZAS01 spores- analysis of differential gene expression and ion exchange. Food Research International. 2018; 116 ():578-585.
Chicago/Turabian StyleAswathi Soni; Indrawati Oey; Patrick Silcock; Elizabeth Permina; Phil J. Bremer. 2018. "Effect of cold storage and different ions on the thermal resistance of B. cereus NZAS01 spores- analysis of differential gene expression and ion exchange." Food Research International 116, no. : 578-585.
The goal of this research was to optimise sous vide processing parameters for beef briskets, previously treated with pulsed electric fields (PEF), to enhance meat tenderness while maintaining other quality attributes such as water holding capacity, colour, and collagen solubility. PEF-treated briskets (electric field strength 1.5 kV/cm; specific energy of 90–100 kJ/kg) were subjected to various sous vide temperature and time combinations for the process optimisation using response surface methodology. Sous vide temperature was found to significantly reduce the shear force of PEF-treated meat while time significantly reduced its hardness. In addition, beef briskets processed by PEF prior to sous vide processing showed less variation owing to a reduction in the effect of biological variation on the parameters tested. According to the response optimiser prediction, sous vide processing at 60 °C for 24 h resulted in optimal quality and tenderness. Scanning electron microscopy (SEM) revealed that PEF-treated meat showed evidence of pore formation in connective tissue and polarised-sensitive optical coherence topography (PS-OCT) revealed that the collagen matrix of PEF-treated meat had a reduced birefringence capacity compared to non-PEF-treated meat, which indicated a breakdown of the collagen.
A. U. Alahakoon; I. Oey; P. Bremer; P. Silcock. Optimisation of Sous Vide Processing Parameters for Pulsed Electric Fields Treated Beef Briskets. Food and Bioprocess Technology 2018, 11, 2055 -2066.
AMA StyleA. U. Alahakoon, I. Oey, P. Bremer, P. Silcock. Optimisation of Sous Vide Processing Parameters for Pulsed Electric Fields Treated Beef Briskets. Food and Bioprocess Technology. 2018; 11 (11):2055-2066.
Chicago/Turabian StyleA. U. Alahakoon; I. Oey; P. Bremer; P. Silcock. 2018. "Optimisation of Sous Vide Processing Parameters for Pulsed Electric Fields Treated Beef Briskets." Food and Bioprocess Technology 11, no. 11: 2055-2066.
Purpose The purpose of this paper is to gain insight on parental attitudes towards weaning practices and weaning foods for health in Malaysia using Q-methodology. Design/methodology/approach The study population was parents that had a child aged three years or less. A total of 47 parents were recruited to partake in a one-on-one activity which involved sorting 69 statements about weaning practices and weaning food products into a grid that was normally distributed ranging from “strongly disagree” to “strongly agree”. Sorting was immediately followed by a short interview to understand the reasons behind the placement of particular statements. Findings Data analysis identified three statistically distinct participant attitudes towards weaning practices and foods for health that were then interpreted using the rich qualitative data from the post-sort interviews. The attitudes identified were “All Homemade and Natural”, “Commercial Convenience and Trust” and “Balance and Variety”. Originality/value This study identified the dominant sets of attitudes held by Malaysian parents towards weaning practices and weaning foods for health using Q-methodology. To authors’ knowledge, this is the first paper focussing on weaning foods for health, specifically on functional weaning food. This new understanding of shared attitudes will allow product developers, marketers and health communicators to more effectively design their products and their marketing mix to ensure that these messages resonate well with the target audience who want to provide the best weaning foods possible for their children.
Hajar Mohamad; Miranda Mirosa; Phil Bremer; Indrawati Oey. Parental attitudes toward weaning practices and weaning foods for health in Malaysia. British Food Journal 2018, 120, 2466 -2482.
AMA StyleHajar Mohamad, Miranda Mirosa, Phil Bremer, Indrawati Oey. Parental attitudes toward weaning practices and weaning foods for health in Malaysia. British Food Journal. 2018; 120 (10):2466-2482.
Chicago/Turabian StyleHajar Mohamad; Miranda Mirosa; Phil Bremer; Indrawati Oey. 2018. "Parental attitudes toward weaning practices and weaning foods for health in Malaysia." British Food Journal 120, no. 10: 2466-2482.
Aims To monitor temporal changes in the volatile organic compounds (VOCs) profile generated by the metabolic activities of Pseudomonads in real‐time. Methods and Results Three Pseudomonas strains were cultivated in Vogel's broth, supplemented with glucose (0.5 or 1%) and/or protein (egg white powder at 0 or 2%) at 25 °C. Glucose or egg white protein contents influenced the VOCs release profile for alcohols, carbonyls and sulphur derivatives. Increasing glucose content resulted in higher alcohols and ketones contents. Glucose indicated less effect on the VOCs release profile, mainly impacting on individual compounds, such as m/z 89 (3‐methyl‐1‐butanol). In contrast, egg white protein enhanced production of VOCs such as m/z 75 (2‐methyl‐1‐propanol) and m/z 63 (dimethyl sulphide) regardless of glucose level present in the medium. At the end of bacteria growth phase (54, 60 and 72 h), the fingerprint of VOCs was different from the early growth phase. Cells near to the end of their growth phase (54, 60 and 72 h), produced a distinctly different array of compounds compared to those produced in early growth phase, e.g., cyclic compounds were detected in early growth phase whereas sulphur derivatives were more common in late growth phase. Conclusions Pseudomonads‐mediated VOCs fingerprint as a response to varying growth conditions can be identified as latent biomarkers. Significance and Impact of Study Understanding how microbially‐mediated VOCs release profile responds to varying growth conditions can potentially be used as a rapid method for detecting microbial activities in controlled conditions such as food quality systems. This article is protected by copyright. All rights reserved.
Mohsen Zareian; Patrick Silcock; Phil Bremer. Effect of medium compositions on microbially mediated volatile organic compounds release profile. Journal of Applied Microbiology 2018, 125, 813 -827.
AMA StyleMohsen Zareian, Patrick Silcock, Phil Bremer. Effect of medium compositions on microbially mediated volatile organic compounds release profile. Journal of Applied Microbiology. 2018; 125 (3):813-827.
Chicago/Turabian StyleMohsen Zareian; Patrick Silcock; Phil Bremer. 2018. "Effect of medium compositions on microbially mediated volatile organic compounds release profile." Journal of Applied Microbiology 125, no. 3: 813-827.