Permalink for this collection
The Department of Wine, Food and Molecular Biosciences covers course areas including animal and plant science, biochemistry, food science, horticulture, microbiology, sensory science, viticulture and wine science.
Browse
Recent Submissions
Item Open Access Probing biological nitrogen fixation in legumes using Raman spectroscopy(MDPI, 2024-08) Jafari, A; Seth, K; Werner, A; Shi, S; Hofmann, R; Hoyos-Villegas, VBiological nitrogen fixation (BNF) by symbiotic bacteria plays a vital role in sustainable agriculture. However, current quantification methods are often expensive and impractical. This study explores the potential of Raman spectroscopy, a non-invasive technique, for rapid assessment of BNF activity in soybeans. Raman spectra were obtained from soybean plants grown with and without rhizobia bacteria to identify spectral signatures associated with BNF. δN¹⁵ isotope ratio mass spectrometry (IRMS) was used to determine actual BNF percentages. Partial least squares regression (PLSR) was employed to develop a model for BNF quantification based on Raman spectra. The model explained 80% of the variation in BNF activity. To enhance the model’s specificity for BNF detection regardless of nitrogen availability, a subsequent elastic net (Enet) regularisation strategy was implemented. This approach provided insights into key wavenumbers and biochemicals associated with BNF in soybeans.Item Open Access Quality enhancement of Barramundi kamaboko using vortex fluidic device modified starch and fish gelatin(Frontiers Media SA, 2024-11-01) Lin, Jiayi; Wu, Yixiao; Wang, Hao; Jellicoe, Matt; He, Shan; Young, David J; Thennadil, Suresh; Raston, Colin L; Brennan, Charles; Tian, Bin; Abukhadra, Mostafa R; El-Sherbeeny, Ahmed MIntroduction: Prime quality kamaboko (cooked surimi) is produced from Alaska pollock. The main challenge of using cheaper fish fillets, including Barramundi, is achieving similar textures. Methods: Combined with fish gelatin, modified starch by vortex fluidic device was used to enhance the quality of kamaboko made from Barramundi. Results: Modification by a continuous flow vortex fluidic device (VFD) significantly reduces the size of particles of starch relative to conventional homogenization. Blending this VFD-modified starch with fish gelatin resulted in a well-organized cross-linked matrix compared to products manufactured from homogenization modified starch. This led to higher gel strength of the former (1,708.32 g/cm² ) relative to the latter (832.56 g/cm² ). Mixing different proportions of fish gelatin and VFD-processed starch to make Barramundi kamaboko (5, 10, and 15%), yielded a product with greater chewiness relative to Alaska pollock kamaboko. Sensory evaluation indicated that the 5% product was optimal and the 15% product with the highest chewiness (56.10 N) was the least favorable. Discussion: These results clearly indicate the potential of VFD processed starch, blended with fish gelatin to enhances the quality of kamaboko.Item Open Access Effect of succinylation on oxidation–aggregation of low-density lipoprotein and formation of off-flavors in heated egg yolks(Multidisciplinary Digital Publishing Institute (MDPI), 2024-11) Ren, Liuyang; Sun, Cheng; Lv, Ying; Kumar, LokeshThis study examined the effect of succinylation on protein oxidation–aggregation and the formation of off-flavors in heated egg yolks (EYs). The sensory evaluation, content of volatile compounds, stability of low-density lipoprotein (LDL) particles, and oxidation of lipid and protein at six levels of succinylated EY (0.25%, 0.5%, 1%, 2%, 5%, and 10%, w/w) were determined. The results showed that the succinylated thermal EY’s concentration of volatiles and off-flavors was reduced. Oil exudation and lipid and protein oxidation decreased with the improved succinylation degree. Succinylation also reduced the LDL particle size and changed the secondary structure (decreased the β-sheets and increased the α-helices) of protein in LDL particles. Meanwhile, succinylation could effectively change the thermal oxidation–aggregation of LDL protein by introducing succinyl groups with negative charges, thus increasing the stability of LDL particles in succinylated EY during heating. These results further revealed the relationship between the oxidation–aggregation of LDL and the formation of off-flavors in heated EY. These results also help improve the flavor quality of heat-treated EY and expands the application scope of egg products.Publication Embargo Effect of hemp protein hydrolysates on physicochemical properties and digestibility of starch : A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Science at Lincoln University(Lincoln University, 2024) Wu, GaoshengStarch is the main constituent of the human diet and is included in foods either in the gelatinized or retrograded form. This carbohydrate, produced by plants, contains amylose and amylopectin chains. Depending on the plant source, the proportion of these two glycan chains can vary within the granule, which influences the physicochemical behavior of starch in foods, impacting the textural and nutritional properties of the final food product. Over the past decades, researchers have investigated the impact of the presence and/or complexation of various biomolecules (proteins and polyphenols) with starch on its physical, chemical, and nutritional properties. There is limited research on the development of hemp protein and its hydrolysates in combination with various starch molecules, which could be a promising strategy for enhancing the nutritional and health benefits of foods. Exploring the interaction between hemp protein and different starches could lead to novel functional food ingredients with improved nutritional profiles, offering potential for increased health benefits. Firstly, this study compared the functional and nutritional properties of hemp protein hydrolysates (HPH) prepared with 0.5% Bacillus licheniformis (1 minute) and 2% pepsin protease (60 minutes). Hemp protein hydrolyzed by bacterial protease (HPHB) showed enhanced emulsifying capacity of 47.83 mL/g, compared to 45.83 mL/g for hemp protein hydrolyzed by pepsin (HPHP). On the other hand, HPHP exhibited superior oil absorption capacity of 5.46 g/g, compared to 5.18 g/g for HPHB, as well as higher foaming capacity at 31.2%, relative to 28% for HPHB. The amino acid composition, which affects the overall amino acid profile, was determined using High-Performance Liquid Chromatography (HPLC), a precise technique for separating and quantifying individual amino acids. Secondly, when the effects of HPH on the textural, particle size distribution, structural, and rheological properties of normal corn starch (NCS), waxy corn starch (WCS), and high amylose corn starch (HACS), alongside their impact on antioxidant activity and starch digestibility were examined, this study showed the addition of the HPH to the starch significantly modified the textural properties of starch gels, particularly enhancing elasticity and hardness in WCS and NCS and increasing adhesiveness in NCS and HACS. Notable effects were observed with 20% HPHP on WCS elasticity (0.09 N.s), 10% HPHB on WCS hardness (0.57 N), and 20% HPHB on WCS adhesiveness (-0.15 N) (p<0.05). Particle size distribution indicated substantial granule size increases, especially in HACS (e.g., Dx90 increased from 39.19 μm to 771 μm). FT-IR analysis revealed shifts in absorption peaks, suggesting altered hydrogen bonding interactions without new functional groups. Rheological properties varied, with increased storage (G') and loss (G") moduli in NCS-HPH mixtures and general decreases in WCS-HPH and HACS-HPH. Additionally, a significant reduction in rapidly digestible starch (RDS) was observed with 20% HPHP in HACS, while resistant starch (RS) increased by about 10% with 10% HPHB in WCS (p<0.05). Among the starches, 20% HPHP exhibited the highest antioxidant activity with 232.36 μmol TE/g for HACS, 231.60 μmol TE/g for WCS and 210.42 μmol TE/g for NCS, respectively (p<0.05).Item Open Access Bacterial cellulose infusion: A comprehensive investigation into textural, tribological and temporal sensory evaluation of ice creams(Elsevier B.V., 2024-11) Mehta, Annu; Kumar, Lokesh; Serventi, Luca; Morton, James; Torrico, DamirThe study examines how adding bacterial cellulose also referred to as Symbiotic Culture of Bacteria and Yeast (SCOBY) to ice cream affects the textural, tribological, and sensory attributes, particularly texture and mouthfeel perception. Analytical assessments were performed on three types: SCOBY-added ice cream and two reference samples (control and guar gum-added ice creams). Evaluations included physicochemical properties, textural and tribological characteristics, and dynamic sensory mouthfeel using the temporal dominance of sensation (TDS) methodology. SCOBY ice cream showed higher probiotics content, lower pH, and higher acidity than reference samples. The addition of SCOBY increased hardness and altered the textural properties. TDS analysis highlighted distinct temporal dominance patterns, with guar gum ice cream presenting a pronounced mouth/residual coating pre-swallowing, while SCOBY and control ice cream exhibited a thin/fluid perception. The frictional factor at 37 ⁰C was positively correlated with the melting rate, graininess, and thin/fluid perception while negatively correlated with firmness, smoothness and mouthfeel liking. Additionally, the mouthfeel liking was higher with firm, smooth and mouth/residual coating sensations and lower with grainy and thin/fluid perception. In summary, incorporating SCOBY in ice cream formulations can provide health benefits and meet consumer preferences for natural ingredients, while ensuring careful optimization of mouthfeel.Item Open Access Food contamination: Major challenges of the future(Multidisciplinary Digital Publishing Institute (MDPI), 2016-06) Hussain, MalikThis issue of Foods is dedicated to discuss the microbial, chemical and physical contamination challenges of food products. Food contamination is generally defined as foods that are spoiled or tainted because they either contain microorganisms, such as bacteria or parasites, or toxic substances that make them unfit for consumption. A food contaminant can be biological, chemical or physical in nature, with the former being more common. These contaminants have several routes throughout the supply chain (farm to fork) to enter and make a food product unfit for consumption. Bacillus cereus, Campylobacter jejuni, Clostridium botulinum, C. perfrigens, Pathogenic Escherichia coli, Listeria monocytogenes, Salmonella spp., Shigella spp., Pathogenic Staphylococcus aureus, Vibrio cholera, V. parahaemolyticus, V. vulnificus and Yersinia enterocolitica are common bacterial hazards (a type of biological contaminant). Chemical food contaminants that can enter the food supply chain include pesticides, heavy metals, and other alien chemical agents.Item Open Access Effects of apple juice concentrate, blackcurrant concentrate and pectin levels on selected qualities of apple-blackcurrant fruit leather(Multidisciplinary Digital Publishing Institute (MDPI), 2013-09) Diamante, Lemuel; Li, Siwei; Xu, Qianqian; Busch, JanetteA study was conducted to determine the effects of different levels of apple juice concentrate (AJC), blackcurrant concentrate (BCC) and pectin on the moisture content, water activity, color, texture and ascorbic acid content of apple-blackcurrant fruit leather using the response surface methodology. The results showed the moisture content increased with increasing pectin level and with greater increases at higher AJC and BCC levels while the water activity increased with increasing pectin level and with increasing AJC level, at low pectin levels, but with decreasing AJC, at high pectin levels. The chroma decreased with increasing pectin level and with lower values at the middle AJC level. The puncturing force decreased with increasing AJC level but with a lower value at the middle pectin level. Lastly, the ascorbic acid content increased with increasing BCC level regardless of AJC and pectin levels. There is a need to reduce the drying temperature or time of apple-blackcurrant fruit leather just enough to bring the water activity closer to 0.60, thereby increasing the moisture content resulting in higher product yield.Item Open Access Survey of methods used for the enumeration of coliform micro-organisms in New Zealand(Lincoln College, 1974-08) Noonan, M. J.Survey of methods used for the enumeration of coliform micro-organisms in New Zealand, this survey was undertaken at the request of the New Zealand Microbiological Society.Item Open Access On electrostatic interactions of adenosine triphosphate–insulin-degrading enzyme revealed by quantum mechanics/molecular mechanics and molecular dynamics(Higher Education Press, 2024-12) Somin, S; Kulasiri, Don; Samarasinghe, SandhyaThe insulin-degrading enzyme (IDE) plays a significant role in the degradation of the amyloid beta (Aβ), a peptide found in the brain regions of the patients with early Alzheimer’s disease. Adenosine triphosphate (ATP) allosterically regulates the Aβ-degrading activity of IDE. The present study investigates the electrostatic interactions between ATP-IDE at the allosteric site of IDE, including thermostabilities/flexibilities of IDE residues, which have not yet been explored systematically. This study applies the quantum mechanics/molecular mechanics (QM/MM) to the proposed computational model for exploring electrostatic interactions between ATP and IDE. Molecular dynamic (MD) simulations are performed at different temperatures for identifying flexible and thermostable residues of IDE. The proposed computational model predicts QM/MM energy-minimised structures providing the IDE residues (Lys530 and Asp385) with high binding affinities. Considering root mean square fluctuation values during the MD simulations at 300.00 K including heat-shock temperatures (321.15 K and 315.15 K) indicates that Lys530 and Asp385 are also the thermostable residues of IDE, whereas Ser576 and Lys858 have high flexibilities with compromised thermostabilities. The present study sheds light on the phenomenon of biological recognition and interactions at the ATP-binding domain, which may have important implications for pharmacological drug design. The proposed computational model may facilitate the development of allosteric IDE activators/inhibitors, which mimic ATP interactions.Item Open Access A machine learning pipeline for predicting Pinot Noir wine quality from viticulture data: Development and implementation(MDPI AG, 2024-10) Kulasiri, Don; Somin, Sarawoot; Kumara Pathirannahalage, SamanthaThe quality of wine depends upon the quality of the grapes, which, in turn, are affected by different viticulture aspects and the climate during the grape-growing season. Obtaining wine professionals’ judgments of the intrinsic qualities of selected wine products is a time-consuming task. It is also expensive. Instead of waiting for the wine to be produced, it is better to have an idea of the quality before harvesting, so that wine growers and wine manufacturers can use high-quality grapes. The main aim of the present study was to investigate the use of machine learning aspects in predicting Pinot Noir wine quality and to develop a pipeline which represents the major steps from vineyards to wine quality indices. This study is specifically related to Pinot Noir wines based on experiments conducted in vineyards and grapes produced from those vineyards. Climate factors and other wine production factors affect the wine quality, but our emphasis was to relate viticulture parameters to grape composition and then relate the chemical composition to quality as measured by the experts. This pipeline outputs the predicted yield, values for basic parameters of grape juice composition, values for basic parameters of the wine composition, and quality. We also found that the yield could be predicted because of input data related to the characteristics of the vineyards. Finally, through the creation of a web-based application, we investigated the balance of berry yield and wine quality. Using these tools further developed, vineyard owners should be able to predict the quality of the wine they intend to produce from their vineyards before the grapes are even harvested.Item Open Access Phosphorus fertiliser is associated with reduced grass grub (Costelytra giveni) fitness in Epichloë endophyte-infected meadow fescue and perennial ryegrass(John Wiley & Sons Inc., 2024) Hewitt, KG; Hofmann, RW; Ball, OJ; Luo, D; Finch, SC; Bryant, Racheal; Popay, AJBACKGROUND: Fertiliser applications are well-established tools in pasture-based agricultural landscapes. This study focuses on the impact of phosphorus (P) fertiliser on grass grub (Costelytra giveni), a major pasture pest. This research investigates the interplay between P, plant growth, and grass grub fitness in Epichloë endophyte-infected perennial ryegrass (Epichloë sp. LpTG-3 strain AR37) and meadow fescue infected with E. uncinata (strain MaxR; AR1017), alongside their endophyte-free counterparts. In a glasshouse trial, plants were grown in P-enriched soil with varying Olsen P levels (9, 18, 28 or 78 mg L¯¹), and grass grubs were introduced. Their survival and weight gain, and plant performance were measured. In a bioassay, grass grubs were placed in specimen vials with P-enriched soils (Olsen P levels 9, 18, 28 and 78 mg L¯¹) and provided with identical plant material to assess their diet consumption and weight gain. RESULTS: In the glasshouse trial, results highlighted a notable decrease in the survival of grass grub on plants infected with MaxR endophyte, but not with AR37, as well as increasing soil Olsen P levels in both plant species. While grass grub decreased plant performance at the low Olsen P level (9 mg L¯¹), this effect diminished with increasing P. Likewise, results from the bioassay showed a decrease in diet consumption with increasing soil Olsen P levels. In both trials increasing Olsen P levels correlated with diminished grass grub performance, revealing a nuanced relationship between soil fertility and pest dynamics. CONCLUSION: The study underscores the pivotal role of selected Epichloë endophyte–grass associations in mitigating grass grub damage across varying phosphorus levels. This study highlights the potential to integrate P applications for sustainable pest control against grass grub. Further field trials are required to validate these findings.Item Open Access Microbiology and water quality(Lincoln College, 1983) Noonan, MJMicroorganisms can have a major effect on water quality. They can be involved in the transformation of a substance which becomes a pollutant when it enters water (e.g. nitrate-N). Microorganisms can be involved in the accumulation of substances which become toxic at higher concentrations (e.g.heavymetals). Those of sanitary significance can carry genes which can be transferred to cause pathogenic microorganisms to become resistant to antibiotics, they can be pathogens themselves, or they can indicate the possible presence of pathogens. Microorganisms and their activities can affect nonsaline surface waters, marine and groundwaters. Efforts to control their influence can include waste treatment, control of water supplies, and selection of environments into which wastes are discharged. The papers in these proceedings cover many aspects of microorganisms and their activities, particularly as they affect water quality in New Zealand.Item Open Access List of cultures of micro-organisms held in New Zealand and methods for their preservation : collections : Forest Research Institute, National Health Institute, New Zealand Dairy Research Institute, University of Otago, University of Waikato, Wallaceville Animal Research Centre(Lincoln College, 1987) Mulcock, APIn August 1947 a specialist conference on Culture Collections of Micro-organisms was held in London. This meeting recommended the formation of a Commonwealth Organisation to be known as "The British Commonwealth Collections of Micro-organisms". The organisation was charged with: 1. Establishing a Permanent Committee 2. Preparing a Directory of Collections 3. Establishing National Committees 4. Preparation of Catalogues by each Collection 5. Distribution of Cultures (freely and without charge) As a result of the formation of the Commonwealth Committee a New Zealand Committee was set up under the aegis of the New Zealand Department of Science and industrial Research. This Committee set about obtaining from culture collections in New Zealand lists of their holdings. At first it was proposed to publish one directory for the whole Commonwealth, however, this proved impractical and so lists were issued country by country as the material became available. A list prepared by the New Zealand was finally dispatched to London in 1965 and was published in 1968 as the "Commonwealth Collection of Micro-organisms Directory of Collections and List of Species Maintained in New Zealand, HMSO London".Item Open Access The quality and movement of groundwater in alluvial aquifers of New Zealand(Lincoln College. Department of Agricultural Biology, 1979) Noonan, MJThese Proceedings are intended as a record of the meeting on the Quality and Movement of Groundwater in Alluvial Aquifers of New Zealand. The meeting was held at Lincoln College and was the second in a series initiated by the North Canterbury Catchment Board and Regional Water Board in February l978.Item Open Access Biochemical characterisation and production kinetics of high molecular-weight (HMW) putative antibacterial proteins of insect pathogenic Brevibacillus laterosporus isolates(BMC, 2024-12) Babar, TK; Glare, Travis; Hampton, John; Hurst, MRH; Narciso, JBackground Bacterial genomes often encode structures similar to phage capsids (encapsulins) and phage tails which can be induced spontaneously or using genotoxic compounds such as mitomycin C. These high molecular-weight (HMW) putative antibacterial proteins (ABPs) are used against the competitive strains under natural environment. Previously, it was unknown whether these HMW putative ABPs originating from the insect pathogenic Gram-positive, spore-forming bacterium Brevibacillus laterosporus (Bl) isolates (1821L, 1951) are spontaneously induced during the growth and pose a detrimental effect on their own survival. Furthermore, no prior work has been undertaken to determine their biochemical characteristics. Results Using a soft agar overlay method with polyethylene glycol precipitation, a narrow spectrum of bioactivity was found from the precipitated lysate of Bl 1951. Electron micrographs of mitomycin C- induced filtrates showed structures similar to phage capsids and contractile tails. Bioactivity assays of cell free supernatants (CFS) extracted during the growth of Bl 1821L and Bl 1951 suggested spontaneous induction of these HMW putative ABPs with an autocidal activity. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of spontaneously induced putative ABPs showed appearance of ∼ 30 kDa and ∼ 48 kDa bands of varying intensity across all the time intervals during the bacterial growth except in the initial hours. Statistically, spontaneously induced HMW putative ABPs of Bl 1951 exhibited a significant decrease in the number of viable cells of its producer strain after 18 h of growth in liquid. In addition, a significant change in pH and prominent bioactivity of the CFS of this particular time period was noted. Biochemically, the filtered supernatant derived from either Bl 1821L or Bl 1951 maintained bioactivity over a wide range of pH and temperature. Conclusion This study reports the spontaneous induction of HMW putative ABPs (bacteriocins) of Bl 1821L and Bl 1951 isolates during the course of growth with potential autocidal activity which is critically important during production as a potential biopesticide. A narrow spectrum of putative antibacterial activity of Bl 1951 precipitate was found. The stability of HMW putative ABPs of Bl 1821L and Bl 1951 over a wide range of pH and temperature can be useful in expanding the potential of this useful bacterium beyond the insecticidal value.Item Open Access Investigation of potential pollution from a proposed landfill(Lincoln College. Department of Agricultural Biology, 1977) Noonan, MJ; Campbell, AS; Shaw, B; Stanley, RAOf the methods available for the disposal of solid wastes sanitary landfill continues to be the least expensive. There are a number of problems with landfilling, not the least of which is the threat to the purity of underground waters. Since Christchurch city uses a supply of very pure ground water any possible pollution of this water is viewed so seriously that the siting of sanitary landfills in areas where there can be no danger to water supply quality is clearly imperative. Thus an investigation into the effects of dumping domestic and industrial refuse onto an area of sand dunes near Bottle Lake Forest in Christchurch was carried out.Item Open Access Soil contamination by septic tank effluent(Lincoln College, 1973-11) Mulcock, AP; Noonan, MJ; Reay, CAA survey of literature relating to septic tanks and the movement of micro-organisms through soil was made. The septic tank still appears to be the most satisfactory method of treating household wastes. Little experimental evidence is available concerning the movement of microorganisms through soil, but work which has been done indicates that soils vary greatly in their filtering ability. Furthermore soils appear to change in capacity to retain micro-organisms which subsequently die at different rates depending on the nature of the soil. The travel of viruses through ~oil has received negligible attention. Investigations undertaken at two sites in the Tai Tapu Area, near Christchurch, indicated that pollution of the soil by faecal organisms can take place from septic tanks and can extend over quite a wide area. The bacteria may remain viable in the soil for some months, both near the surface and at depth. From samples obtained by drilling holes in the soil it was found that bacteria could apparently move laterally through the soil at 2.0 to 3.0 m depth for considerable distances. Two main conclusions can be drawn from this work. First, soil can become contaminated by septic tank effluent over a wide area. Second, once the soil is contaminated the micro-organisms can persist for long periods.Publication Embargo Factors that influence microbial communities in spontaneously fermented wine, beer, and kombucha: insights from a metabarcoding perspective : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University(Lincoln University, 2024) Ohwofasa, AghoghoIt is well established that the world contains a vast diversity of microbes, many of which have been unexplored and even as yet uncultivated. Advances in molecular biology techniques such as metabarcoding have helped in improving our insights into this complex microbial world, in every aspect of human civilization, including food and beverage production. The importance of microbial diversity in the processing of wine and other fermented products in general cannot be overemphasized. In wine for example, grape health and the diversity of microorganisms introduced into the winery depends on the number of microbes who are able to form ecological niches in the vine and soil of the vineyard. With extensive knowledge of microbiome diversity and its interactions or shifts within fermentation processes, this could lead to an improved understanding of this activity. With next generation Sequencing (NGS) techniques, it is now feasible to accurately detect and quantify the relative abundance of microbes found in and around these products. Culture based methods previously used in microbial analysis neglects the non-culturable microbial fraction, an advantage NGS methods possesses over culture based techniques. Performing complex multifactorial analyses is now possible by coupling metabarcoding with bioinformatics tools. This is fast becoming the “go to” strategy in monitoring, traceability of products and diagnostic purposes. If properly harnessed, metabarcoding opens up the possibility of adequately monitoring and describing the microbial population during fermentation and how their profile changes with time. The aim of this research was to employ metabarcoding in exploring the microbiomes associated with spontaneously fermented wine and other foods/products such as kombucha and lambic styled beer in New Zealand. These studies included investigating the influences that the environment and/or climate play in shaping the microbiome of these products. Where applicable, the complex relationship between the microorganisms and the organoleptic and chemical properties of the products was also probed. The first experiment in this work explored the impact of differing environmental systems on the microbial communities utilized by an organic winemaker in producing wines. Results indicated that T. delbrueckii and Fructobacillus could be affected by environmental conditions as they were detected in one system but not the other. Together, significant differences were reported between the fungal (RANOSIM = 0.603, p = 0.0001) and bacterial (RANOSIM = 0.5814, p = 0.0001) diversity found in both systems. Assessment of these microbial differences were done to see if they brought about detectable sensory or chemical variations in the resulting wines. Certain volatile compounds were only found in wines from one of the environmental system but not the other, indicating that significantly different bacterial and/or fungal species could have major roles in synthesising these compounds. Specifically, it can be inferred that Gluconobacter may play a role in the taste (bitterness) and ‘mouth feel’ (astringency/tannin) attributes of Pinot noir wines. To gain insights into how the microbial communities associated with kombucha production might differ based on scale (large commercial scale as compared to a small scale production), another experiment was carried out. For the first time in kombucha literature, results uncovered indicated that the fungal and bacterial diversity associated with the commercial fermentation process had a higher diversity as compared to small scale kombucha production. Interestingly, the core fungal microbiome found in the SCOBY and tea phase of both the commercial and small-scale kombucha types were similar. Using linear modelling unravelled how Komagataeibacter might play a key role and shape the pH of kombucha. To understand if the microbial communities detected at the end of spontaneous beer fermentation varies across vintages, a beer experiment was conducted. Results from this experiment revealed how vintage has a huge influence in shaping the detected microbial populations. Climatic factors such as humidity and maximum temperature were identified as variables that may enhance the relative abundance of Penicillium and Hanseniaspora in beer microbiota. When the microbiome of all three fermented food/products were compared, in comparison to the bacterial communities, similarities can be seen with the fungal populations. Spontaneously fermented wine and kombucha fermentation had considerable amounts of Hanseniaspora, Metschnikowia and Saccharomyces. Beer and kombucha fermentation had substantial Brettanomyces and Saccharomyces proportions. Saccharomyces was the only genus present in significant amounts in all three foods/products. For bacteria, spontaneously fermented Pinot noir wine was dominated by Tatumella (2021 vintage) and Lactococcus (2018 vintage). Komagataeibacter and Gluconobacter were abundant in the home and commercial kombucha brew respectively. Lambic styled beer saw Pediococcus as the most dominant bacteria. Summarily, this research unravelled the complex microbiome of spontaneous Pinot noir wine fermentation, kombucha fermentation and lambic beer brewing. Description of how microbial populations can be affected by environmental and/or climatic influences were done. Where applicable, how these microbial differences could result in sensory and/or chemical variations in the resultant product were assessed. This study has described how metabarcoding can be reliable in assessing the microbiome of fermented food/products.Item Open Access Perspective chapter: Numerical solutions for modelling complex systems with Stochastic Differential and Partial Differential Equations (SDEs/SPDEs)(InTech Open, 2024-07-31) Tiwari, Parul; Kulasiri, Don; Samarasinghe, Sandhya; Kulasiri, DonUnderstanding phenomena ranging from biological processes to financial markets involves uncertainty. Stochastic Differential Equations (SDEs) and Stochastic Partial Differential Equations (SPDEs) serve as robust mathematical frameworks for modelling such systems. Given the stochastic influences within these models, comprehending the dynamics of complex systems becomes pivotal for accurately predicting system behaviour. However, traditional numerical techniques frequently encounter challenges in effectively addressing the intricacies and stochastic properties inherent in these equations. This chapter explores several numerical methods that offer streamlined and dependable solutions capable of handling the complexities inherent in stochastic differential and partial differential equations. Also, numerical challenges associated with these methods are discussed and the solution strategies are also suggested.Item Open Access Elephantopus scaber L. polysaccharides alleviate heat stress-induced systemic inflammation in mice via modulation of characteristic gut microbiota and metabolites(Multidisciplinary Digital Publishing Institute (MDPI), 2024-01) Wang, Chen; Sun, Dongfang; Deng, Qi; Sun, Lijun; Hu, Lianhua; Fang, Zhijia; Zhao, Jian; Gooneratne, RaviElephantopus scaber L. (ESL) is a Chinese herb that is used both as a food and medicine, often being added to soups in summer in south China to relieve heat stress (HS), but its exact mechanism of action is unknown. In this study, heat-stressed mice were gavaged with ESL polysaccharides (ESLP) at 0, 150, 300, and 450 mg/kg/d‾¹ (n = 5) for seven days. The gut microbiota composition, short-chain fatty acids (SCFAs), seven neurotransmitters in faeces, expression of intestinal epithelial tight junction (TJ) proteins (Claudin-1, Occludin), and serum inflammatory cytokines were measured. The low dose of ESLP (ESLL) improved the adverse physiological conditions; significantly reduced the cytokines (TNF-α, IL-1β, IL-6) and lipopolysaccharide (LPS) levels (p < 0.05); upregulated the expression of Claudin-1; restored the gut microbiota composition including Achromobacter and Oscillospira, which were at similar levels to those in the normal control group; significantly increased beneficial SCFAs like butyric acid and 5-HT levels in the faeces of heat-stressed mice; and significantly decreased the valeric acid and glutamic acid level. The level of inflammatory markers significantly correlated with the above-mentioned indicators (p < 0.05). Thus, ESLL reduced the HS-induced systemic inflammation by optimizing gut microbiota (Achromobacter, Oscillospira) abundance, increasing gut beneficial SCFAs like butyric acid and 5-HT levels, and reducing gut valeric and glutamic acid levels.