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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.
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Item Restricted Microbiomes in action: multifaceted benefits and challenges across academic disciplines(Frontiers Media S.A., 2025-03-18) Soth, S; Hampton, John; Alizadeh, Hossein; Wakelin, SA; Mendoza - Mendoza, ArtemioMicrobiomes combine the species and activities of all microorganisms living together in a specific habitat. They comprise unique ecological niches with influences that scale from local to global ecosystems. Understanding the connectivity of microbiomes across academic disciplines is important to help mitigate global climate change, reduce food insecurity, control harmful diseases, and ensure environmental sustainability. However, most publications refer to individual microbiomes, and those integrating two or more related disciplines are rare. This review examines the multifaceted benefits of microbiomes across agriculture, food manufacturing and preservation, the natural environment, human health, and biocatalyst processes. Plant microbiomes, by improving plant nutrient cycling and increasing plant abiotic and biotic stress resilience, have increased crop yields by over 20%. Food microbiomes generate approximately USD 30 billion to the global economy through the fermented food industry alone. Environmental microbiomes help detoxify pollutants, absorb more than 90% of heavy metals, and facilitate carbon sequestration. For human microbiomes, an adult person can carry up to 38 trillion microbes which regulate well being, immune functionality, reproductive function, and disease prevention. Microbiomes are used to optimize biocatalyst processes which produce bioenergy and biochemicals; bioethanol production alone is valued at over USD 83 billion p.a. However, challenges, including knowledge gaps, engaging indigenous communities, technical limitations, regulatory considerations, the need for interdisciplinary collaboration, and ethical issues, must be overcome before the potential for microbiomes can be more effectively realized.Item Open Access A review of systems biology of axon initial segment: Action potential initiation, propagation, and neurological diseases(MDPI, 2024-10-11) Bardwaj, Piyush; Kulasiri, Don; Samarasinghe, Sandhya; Zhang, YanThe axon initial segment (AIS) region is crucial for action potential (AP) initiation due to its molecular organization especially voltage gated ion channels and Ankyrin-G (AnkG). AnkG act as recruiter and restrict almost all the proteins at AIS in order to maintain the AIS assembly. Voltage gated sodium channels (Nav channels) are enriched at AIS with high density and independently responsible for the AP initiation. Moreover, AIS also contains voltage gated potassium channels (Kv channels) for repolarization phase of AP, microtubules (MTs) responsible for the proper protein trafficking through molecular motors. AIS also acts as a cytoplasmic filter and diffusion barrier, responsible for the selective entry of the proteins into axon. Mutation of AIS related protein can cause various neurological dysfunction including Alzheimer’s disease. This review also reflects the role and importance of computational modelling in the understanding of action potential mechanisms mathematically.Item Open Access The primary cilia are associated with the axon initial segment in neurons(Wiley-Blackwell, 2025-03-06) Wang, H; Li, Y; Li, X; Sun, Z; Yu, F; Pashang, A; Kulasiri, Don; Li, HW; Chen, H; Hou, H; Zhang, YThe primary cilia serve as pivotal mediators of environmental signals and play crucial roles in neuronal responses. Disruption of ciliary function has been implicated in neuronal circuit disorders and aberrant neuronal excitability. However, the precise mechanisms remain elusive. To study the link between the primary cilia and neuronal excitability, manipulation of somatostatin receptor 3 (SSTR3) is investigated, as an example of how alterations in ciliary signaling may affect neuronal activity. It is found that aberrant SSTR3 expression perturbed not only ciliary morphology but also disrupted ciliary signaling cascades. Genetic deletion of SSTR3 resulted in perturbed spatial memory and synaptic plasticity. The axon initial segment (AIS) is a specialized region in the axon where action potentials are initiated. Interestingly, loss of ciliary SSTR3 led to decrease of Akt-dependent cyclic AMP-response element binding protein (CREB)-mediated transcription at the AIS, specifically downregulating AIS master organizer adaptor protein ankyrin G (AnkG) expression. In addition, alterations of other ciliary proteins serotonin 6 receptor (5-HT6R)and intraflagellar transport protein 88 (IFT88) also induced length changes of the AIS. The findings elucidate a specific interaction between the primary cilia and AIS, providing insight into the impact of the primary cilia on neuronal excitability and circuit integrity.Publication Restricted Understanding the bioaccessibility of grape phenolics in association with milk proteins : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University(Lincoln University, 2025) Matiwalage, Iresha Nirmalie WickramanayakePhenolics are compounds that are widespread in plants and abundant in many fruits. Grapes and their products contain high concentrations of phenolics, particularly anthocyanins, and flavanols such as catechins and epicatechins. phenolics have been reported to have various health benefits, but these may be limited by their low uptake, low bioavailability, and rapid degradation owing to enzymatic and non-enzymatic reactions during digestion. Research has explored several protected delivery options to increase the bioavailability of phenolics in different fruits. Milk proteins have been identified as effective delivery agents for several bioactive compounds including phenolics. Although milk proteins are effective delivery agents for phenolic compounds, the specific interactions of the phenolics with the milk proteins, and factors affecting phenolic-protein interactions require to be understood to facilitate the utilisation of these delivery systems in food, nutraceutical, and pharmaceutical applications. Commercially available extracts of red grape skin from Pinot Noir, grape seed from Sauvignon Blanc, and sodium caseinate 180 were used in this study. Grape extracts and Na-casein protein stock solutions were separately prepared and mixed at different phenolic-to-protein weight ratios, 5:40, 10:40, and 15:40, phenolic-alone controls (5:0, 10:0, and 15:0) and casein-alone control (0:40) in phosphate-buffered saline (PBS). The protein phenolic complex samples were then freeze-dried. In the casein-based grape samples, the total extractable phenolic contents increased from a phenolic-toprotein ratio of 5:40 to 15:40. The percentages were 47.0% in CSK5 to 69.1% in CSK15 and 41.3% in CSE5 to 54.8% in CSE15 in casein-based skin and seed FD samples respectively. Further analysis by HPLC found that catechin, epicatechin, epigallocatechin gallate, gallic acid, and quercetin-3-glucoside were the abundant phenolics in casein-based skin whereas in casein-based seed samples, procyanidin B1, procyanidin B2, catechin, epicatechin and epigallocatechin gallate were the major phenolics. The antioxidant capacity was reflected in the total extractable phenolic content and strong positive linear correlations were found between the total extractable phenolic content and the antioxidant activity and between ABTS and DPPH assays in FD samples. The free phenolic results from the loading efficiency study and total extractable phenolic contents revealed that grape phenolics are more likely to bind with casein when a sample contains a higher protein concentration (e.g. 5:40 phenolic-to-protein ratio containing sample). In the same way, DH% results displayed that protein hydrolysis of casein-based grape skin FD samples was significantly increased during in-vitro digestion, and the increasing order being CSK0 < CSK5 < CSK10 < CSK15 shows that protein hydrolysis is more favourable with the sample having a lower proportion of protein. Significant increases (p<0.05) in phenolic release were noted in three different phenolic-to-protein ratios after one hour of pepsin addition. In contrast, phenolic-alone skin samples showed significant reductions (p<0.05) in phenolic release under acidic pH conditions one hour after adding pepsin indicating rapid phenolic degradation. Even though, both casein-based and phenolic-alone grape skin samples showed a notable increase in phenolic content one hour after pancreatin addition, again it declined during the final two hours in the phenolic-alone skin samples. No differences were found in the phenolic content of three casein-based samples after five hours of digestion resulting in a slower release of phenolics during in-vitro digestion even with the sample having a lower phenolic-to-protein ratio. Reliable with the trends noted in DH% and phenolic release, the antioxidant activity was increased in casein-based grape samples. FT-IR results discovered that grape phenolics interact with casein mainly via non-covalent bonding like hydrogen bonding, hydrophobic, and electrostatic interactions, and no covalent bonds were formed during the formation of casein-grape phenolic complexes. In addition, grape phenolics appear to alter casein's secondary structure by decreasing β-sheet and random coil contents and increasing β-turn and α-helix structures, reflecting increased hydrogen bonding and protein conformational changes, leading to flexible and disordered protein structure and antioxidant activity of casein. The findings of the fluorescence quenching study revealed that adding different concentrations of grape skin and seed phenolics caused to significant decrease in fluorescence intensity of the main emission band of Nacaseinate and the shift of the emission peak slightly toward a higher wavelength. Moreover, both dynamic and static quenching mechanisms were involved with samples at a higher phenolic-to-protein ratio. The highest modified Stern–Volmer quenching constant (K), 4.6 x 10³ M⁻¹ and quenching constant (Kq), 1.5 x 10¹² M⁻¹s⁻¹ at 280 nm excitation wavelengths at room temperature of grape skin phenolics showed stronger quenching interactions and greater binding affinity towards casein protein indicating higher radical scavenging activity in casein. Furthermore, the binding constants (KA) for casein-based skin, 3.49 x 10⁷ M⁻¹ at 290 nm excitation wavelength revealed stronger static quenching interactions between skin phenolics and casein protein. Overall, findings based on protein hydrolysis, phenolic release, antioxidant activity during in-vitro digestion, and the interactions between grape phenolics and casein protein, which together enhance bioaccessibility during digestion, this study confirmed that casein-based grape FD powders are an effective food complex, beneficial for the nutraceutical and food industries.Item Embargo The food fight - overcoming the challenges of food fraud(New Zealand Institute of Primary Industry Management, 2025-03) Rombach, Meike; Tangiora, HirainaThis article discusses food fraud in New Zealand’s food and fibre sector. It outlines common types of food fraud, means of detection, challenges, suggestions to deal with it, matters of legality and regulatory oversight, and information on how to report it.Publication Embargo Development and characterisation of functional walnut oil blends enriched with marine omega-3 fatty acids : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Food Innovation at Lincoln University(Lincoln University, 2025) Annu, BenWalnut oil is rich in PUFAs, particularly linoleic acid (50-63%) and alpha-linolenic acid (11-19%). However, it lacks long-chain omega-3 fatty acids like docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), essential for brain health and development. It also has a high n-6/n-3 ratio (4:1) which is not ideal for a balanced fatty acid profile. This study aimed to enhance walnut oil’s DHA and EPA content by blending it with four marine-based oils: krill, algal, mussel, Hoki fish oils, at varying concentrations (10%, 20% and 30%, w/w) and to develop functional walnut oil blends. To achieve the goal, this study assessed their fatty acid composition, the effect of blending on the positional distribution of omega-3 fatty acids and the oxidative stability (PV, AV) at room temperature (22℃) over storage periods (0, 3, 6, 9, 30 days). Results showed that walnut oil blended with 30% algal oil (walnut+30% algal) had the highest n-3 content (31.21 g/100 g fatty acids) and DHA concentration (12.8 g/100 g). In contrast, the walnut+30% mussel and walnut+30% Hoki oil blends had lower DHA levels (3.5 and 2.8 g/100 g, respectively). EPA content was similar across walnut+30%-marine based oil (krill, algal and mussel) blends (5.5 - 4.9 g/100 g). ALA was highest (15 g/100g each) in the walnut+10% krill and walnut+10% mussel oil blends, slightly lower in walnut+10% Hoki (14.9 g/100 g) and walnut+10% algal (14.6 g/100 g) oil blends. Positional distribution of fatty acids in triglycerides (TAG) revealed that DHA was mainly retained at sn-2 position in the 30% algal oil blends. EPA was consistently positioned at sn-2 position in all 30% blends. Oxidative stability tests showed that walnut+30% krill oil blend had the best stability (PV, 5.75 meq O2/kg oil after 30 days) while walnut+30% algal oil blend was more prone to oxidation (PV, 14.45 meq O2/kg). However, walnut+30%krill oil blend were more susceptible to hydrolysis (AV, 3.91 mm KOH/g) whereas walnut+30%algal oil blend was more resistant (AV, 3.44 mm KOH/g). This study concluded that walnut+30% krill oil blend offered the best balance of oxidative stability and omega-3 enrichment. The walnut+30% algal oil blend had the highest omega-3 content with DHA predominantly retained at the sn-2 position. These findings suggest that blending walnut oil with marine oils can enhance the nutritional value, making it a potential functional food ingredient. Future studies should investigate storage stability under acceleratetd conditions to better understand shelf life.Publication Restricted Optimising texture-modified foods for dysphagia: An instrumental assessment for the effects of hydrocolloids and particle size in a chickpea model : A Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Food innovation(Lincoln University, 2025) Dhaval PatelThis study investigated the rheological and textural properties of a chickpea-based model system for dysphagia management. Chickpeas (cooked) were selected for their nutritional profile and soft texture, processed into distinct particle sizes (150 µm–2.36 mm), and combined with Xanthan gum (XG) or carboxymethyl cellulose (CMC at concentrations (0.36–2%). Rheological measurements focused on yield stress, shear viscosity, and oscillatory frequency sweep tests, while hardness was assessed by texture profile analysis. Results revealed XG imparted significantly higher yield stress (73.55 vs. 18.79 Pa for CMC) and consistency coefficients (p < 0.0001), attributed to its rigid molecular structure, while CMC exhibited greater hardness (Force = 157.07 gram) in high-particle-size systems. Particle size critically influenced texture, with larger particles (2.00 – 2.36 mm) enhancing yield stress (64.56 Pa), consistency, and elastic modulus (G') due to increased structural rigidity. Oscillatory tests confirmed elastic dominance (G' > G'') across all samples, essential for bolus integrity. Particle size exerted a notable effect: larger particles increased yield stress and viscosity, likely by creating a more rigid, cohesive matrix. Texture analysis demonstrated that low-viscosity CMC formulations with coarse particles unexpectedly increased hardness, highlighting the interplay between gum type, gum concentration, and particle size in tailoring food consistency. The findings underscore the potential of modulating particle size and hydrocolloid selection to design dysphagia-friendly foods. Researchers and food developers can achieve specific textural targets—such as yield stress levels conducive to bolus formation—aligned with International Dysphagia Diet Standardization Initiative (IDDSI) recommendations. Although the focus was on 100 s⁻¹ shear conditions relevant to swallowing, further investigations should explore the full shear rate range encountered during oral processing and validate outcomes with direct IDDSI tests and Sensory and clinical assessments. Overall, this work provides a framework for developing nutrient-dense, texture-modified foods through synergistic control of particle size and hydrocolloid functionality, potentially improving both the safety and sensory acceptability of dysphagia diets.Publication Embargo Exploring the synergistic effects of Grape seed tannin and psyllium husk fiber on the nutritional profile of starch : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Food Innovation at Lincoln University(Lincoln University, 2025) Kalia, AnkitaStarch is super versatile complex carbohydrate and a vital macronutrient providing energy to human body by breaking down into sugars. Starch structure and physicochemical properties vary from one source to another due to its interaction in food matrix. Interaction of starch with bioactive compounds such as tannins and fibre alter its textural and physicochemical properties by enhancing the overall nutritional profile. These interactions lead to production of functional foods having low glycaemic index. This study aimed to develop starch-fibre and starch-fibre-tannin complexes using corn starch (5%), grape seed tannins (0.5% by starch weight) and psyllium husk fibre (5% and 10%). The gels were prepared using Rapid Visco Analyser (RVA). Various analyses were conducted to capture the effect of fibre alone and fibre-tannin complex on starch properties. RVA studies showed an increase in the pasting viscosity of starch upon complexation with both fibres alone and the fibre-tannin complex. Starch-iodine binding studies were further conducted to unravel the mechanism of interaction between starch-fibre and starch-fibre-tannin with varied fibre concentrations. Decline in absorbance near 500-540 nm and 540-660 nm was observed in fibre only complex signifying that starch amylose helix was not available for iodine binding. Particle size distribution also showed variation in particle sizes of starch-fibre and starch-fibre-tannin complex in contrast to the control corn starch. Starch textural properties, including firmness, consistency, cohesiveness, and index of viscosity, were significantly affected by the addition of fibre alone and the fibre-tannin complex. Addition of fibre at both 5% and 10 % concentrations increased the firmness and consistency in all treatments compared to corn starch sample. The 5% fibre-tannin complex exhibited the highest antioxidant activity, indicating that tannins had greater ability to reduce Fe3+ ions in the presence of 5% fibre compared to 10% fibre concentrations, both before and after incubation in the FRAP assay. A similar trend was observed in the ABTS assay. Therefore, highlighting the contribution of fibre-tannin complexes in improving the antioxidant ability of starch-based foods. A significant decrease in RDS content and an increase SDS and RS content was observed in all samples compared to control starch during in-vitro starch digestibility, which could be a contributing factor in improving overall nutritional properties of starchy foods.Publication Embargo Optimising the flavour and aroma of gin using mixture design and single botanical distillation : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Food Innovation at Lincoln University(Lincoln University, 2024) Shibata, KeiyuThis dissertation investigates the optimisation of gin production through single botanical distillation and the Design of Experiments (DoE) methodology, focusing on blending ratios of botanicals to enhance consumer preference. The single botanical distillation allows for the individual distillation of botanicals at their optimal cutting points, enabling precise flavour and aroma expression. This contrasts with traditional one-shot distillation, where all botanicals are distilled simultaneously, often leading to over- or under-expression of flavours. Using a mixture design within the DoE framework, the research identifies optimal blending ratios for five botanicals: juniper berries, kawakawa, horopito, mānuka, and tarata. Sensory analysis with Check-All-That-Apply (CATA) and a 9-point hedonic scale revealed that "smooth" was a critical factor for consumer preference, while attributes like "nutty" and "chemical" were less favoured. Additionally, Preference mapping highlighted "juniper," "floral," and "citrus" as key drivers of liking. Mixture design analysis found that Botanical 1 and Botanical 2 positively influenced liking scores in higher proportions, while Botanical 3 and Botanical 4 showed negative trends at higher concentrations, and Botanical 5 contributed positively when used moderately. The predicted optimal formulation was identified as Botanical 1-5 with specific percentages, yielding a liking score of 6.04 on a 9-point scale. However, further refinement and larger-scale evaluations are recommended to achieve higher scores. This research underscores the potential of single botanical distillation and DoE in crafting gins that align with consumer preferences, emphasising the importance of "smooth" and balanced botanical proportions. The findings offer valuable insights for craft distilleries aiming to innovate and optimize gin formulations, paving the way for future research in flavour and aroma optimisation and consumer-driven product development.Publication Open Access Unlocking the potential of faba bean blanching water: From waste to ingredient - Insights into composition, cholesterol-lowering property, and bakery application : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University(Lincoln University, 2024) Feng, ZiqianThe rising demand for sustainable food systems has driven interest in upcycling byproducts from legume processing. This thesis examines the potential of faba bean blanching water (FBBW), a byproduct commonly wasted in faba bean processing, as a source of bioactive compounds and its use in food production. The aims were to investigate the nutritional and bioactive composition of FBBW, evaluate its cholesterol-lowering properties, and assess its efficacy as an ingredient in baked goods. The research involved a compositional analysis of FBBW, including the quantification of carbohydrates, proteins, peptides, amino acids, phytochemicals, and minerals. In vitro assays were performed to test the inhibitory effects of FBBW on HMG-CoA reductase, as well as its impact on cholesterol micellization. Finally, FBBW was incorporated into sponge cakes to evaluate its effects on texture, sensory attributes, and consumer acceptance. The results indicated that bioactive compounds are abundant in FBBW dry matter, including peptides, saponins, and phenolic compounds, all of which contribute to its specific health-promoting attributes. Notably, the peptides in FBBW significantly inhibited HMG-CoA reductase, a key enzyme in cholesterol production, with the inhibitory activity at 64 – 70%. This enzyme inhibition is important for lowering cholesterol levels because it reduces the rate of cholesterol synthesis in the liver. Saponins, which were the predominant component of FBBW, also reduced cholesterol by decreasing cholesterol micellization, a mechanism required for cholesterol absorption in the gut, with the inhibition at 48 – 53%. Saponins significantly reduced cholesterol’s bioavailability, restricting its absorption and contributing to a decrease in overall cholesterol levels. This dual-action mechanism of FBBW shows that it has the potential to effectively manage cholesterol levels while also improving cardiovascular health. Furthermore, FBBW was investigated for its potential as a functional element in food applications, particularly baking products like sponge cakes. When FBBW was added to sponge cake formulations, it improved physicochemical aspects, including texture and adhesiveness. Textural improvements were observed as enhanced softness and cohesion, resulting in a more pleasant mouthfeel. Textural study utilizing instrumental analysis supported these findings, demonstrating that cakes containing FBBW had better adhesiveness (P < 0.05) and moisture retention (P < 0.05). Importantly, consumer sensory evaluations confirmed these instrumental findings, with desirable acceptance ratings for overall satisfaction (P > 0.05) and similar flavour and textural acceptance. Thus FBBW not only has potential for better health outcomes but also provides useful functional qualitites as a food ingredient. These findings highlight the adaptability of FBBW as a sustainable, functional ingredient that may promote health and reduces food waste.Publication Open Access Development of functional food with pea cooking water and the effect on human postprandial glycaemic response : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University(Lincoln University, 2024) Zhang, YanyuHigh GI carbohydrates are associated with several diseases, including diabetes, obesity, and cardiovascular disease (CVD). The rate of starch digestion and absorption significantly impacts metabolic responses. Slowly digestible carbohydrates are advantageous for managing metabolic disorders such as diabetes and hyperlipidaemia and are found in legumes, pasta, and whole-grain cereals. Peas, a high-quality protein source, are typically consumed after soaking and cooking. Pea cooking water is the by-product of split yellow peas, often regarded as an ideal egg white substitute in bakery products due to its emulsifying properties. Pea cooking water (PCW) was recently reported to be rich in proteins, fibres and micronutrients. However, current research has not specifically investigated the nutritional aspects of pea cooking water, although significant nutrient loss is known to occur during cooking. This study investigated the potential of pea cooking water to manage glycaemic responses in carbohydrate-rich foods by examining its effects on human glycaemic levels as well as the structural and textural properties of these foods. This study examines the structural and nutritional modifications that occour to pasta when PCW or pea flour (PF) are incorporated into the formulation. The inclusion of freeze-dried PCW (PCWFD) in pasta significantly (P<0.05) reduced the optimal cooking time (OCT) and altered water absorption capacity due to its unique structural attributes. Compared to traditional wheat pasta, PCWP exhibited a lower OCT (P<0.05), reduced swelling index (P<0.05), and higher cooking loss when substituting 20% of semolina with PCWFD (P<0.05). Additionally, pasta substituted semlina with 10% and 20% PCWFD showed increased tensile strength and decreased cutting force (P<0.05), maintaining an intact microstructure and consistent particle size distribution. The incorporation of PCWFD modified protein-starch network of the pasta. The modified protein-starch networks in PCWP and PFP resulted in slower glucose release and a lower glycaemic response (P<0.05). The study explored the impact of varying cooking times and PCWFD levels, finding that longer cooking times and higher PCWFD concentrations affect cooking loss and water absorption, influencing glycaemic response. PCWP performs comparably or better than traditional pea flour pasta in in vitro glucose digestion tests. The food matrix does not disrupt the effect of PCW in reducing and slowing glucose release, as demonstrated by comparisons with rice boiled in PCW versus normal water. PCW incorporation significantly reduced postprandial glycaemic responses in human subjects (P<0.05), attributed to the high protein content and fibre effects on gastric emptying. The lower glycaemic index (GI) effect is also due to the higher protein content, lower starch content, and protein-starch interactions. Despite a fully gelatinized structure, PCWP maintain a reduced glycaemic response. These findings highlight the potential of PCW as a functional ingredient to enhance the nutritional profile of pasta, reduce glycaemic responses, and promote sustainable food processing practices. The present work addressed the potential health benefits of PCW to develop of functional food by investigating the effect on human postprandial glycaemic response. It represented a functional and innovative approach to food development while promoting environmentally sustainable practices.Item Open Access Starch-tannin interactions: Influence of grape tannins on structure, texture, and digestibility of starches from different botanical sources(Elsevier, 2025-05) Kaur, H; Mehta, A; Kumar, LokeshThis study investigated the effect of grape seed (GSd) and grape skin (GSk) tannins on the physicochemical, rheological properties and in-vitro digestibility of starches (corn, pea and wheat) derived from three different botanical sources. Quantification of bound and unbound tannins using MCP and HPLC analysis demonstrated that majority of the tannins were bound to starch molecules. The results of particle size distribution, starch-iodine binding and FTIR studies indicated the development of inclusion complexes through hydrophobic interactions with tannins in pea starch, while other two starches prominently formed non-inclusion complexes via hydrogen bonding. Back extrusion analysis of textural properties indicated that wheat starch-tannin complexes resulted in firmer starch-tannin gels compared to other two starches. Rheological studies revealed an increase in the viscoelastic modulus (G’ and G”) with improved elastic behavior for all starch-tannin gels. Starches complexed with tannins demonstrated strong antioxidant properties and in-vitro starch digestion studies revealed significant reductions in rapidly digestible starch (RDS) and slowly digestible starch (SDS), along with an increase in resistant starch (RS), particularly in pea starch complexed with GSd tannins. This study enhanced our understanding of how GSd and GSk tannins influence the properties of starches from various botanical origins, helping in understanding starch-tannin interactions and enabling the creation of foods with improved texture and digestibility.Publication Open Access Edible insects, mātauranga, diet, and lifestage to explore the potential of Aotearoa New Zealand insects as food : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University(Lincoln University, 2025) O'Connor, Chrystal Te OhorereWith growing global concerns about food security and environmental sustainability, insects as food could provide a promising alternative protein source. However, research on entomophagy (eating insects) has predominantly focused on Western perspectives, who perceive edible insects as a novel concept, and there is limited exploration of Indigenous knowledge systems. This thesis investigates the potential of native Aotearoa New Zealand insects as sustainable and nutritious food sources, integrating mātauranga Māori (indigenous Māori knowledge) with Western scientific approaches. A survey of Māori participants (n=172) revealed that insects are culturally significant, with 47% of participants having consumed insects or knowing whānau (family) who had. Larvae of the huhu beetle (Prionoplus reticularis White, 1843) was identified as the most consumed insect, with 89% of participants naming it as a traditional food source. The survey also indicated that participants were significantly more likely to consume insects that were native to Aotearoa New Zealand, fed rākau rongoā (medicinal plants), or historically eaten by Māori (P<0.05). Most participants indicated they would eat insects either processed or whole (49%, N=78), with a total of 87% of participants indicating they would be willing to eat insects in some form (processed 37%, N=59, whole 4%, N=7). Through integration of mātauranga Māori, ecological factors, and nutritional considerations, three Lepidoptera species were selected and studied as whole insects; kawakawa looper (Cleora scriptaria (Walker, 1860)), brindled bell moth (Epalxiphora axenana Meyrick, 1881), and brown headed leafroller (Ctenopseustis obliquana (Walker, 1863)), and two culturally significant plant diets; kawakawa (Macropiper excelsum (G.Forst.) Miq.), and mānuka (Leptospermum scoparium Forst.). The selection process considered factors such as sustainability of rearing processes, life cycle length, plant associations, and cultural significance. Amino acid (AA) and mineral analysis, using high-performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP-MS) respectively, showed that all three species met FAO/WHO requirements for essential AAs of 40%, with the essential AA to non-EAA ratios ranging from 41.1% to 44.5%. The brindled bell moth showed significantly higher levels of several minerals, including sodium, magnesium, potassium, and calcium, with iron content (21.4 mg/100g dry weight (DW)) (P<0.05) that exceeded New Zealand recommended daily intake. Diet studies with the brown headed leafroller showed that larvae and pupae reared on either mānuka or kawakawa had significantly higher levels of macrominerals, particularly sodium, magnesium, potassium, and phosphorus, compared to those on laboratory diets. Larvae reared on mānuka demonstrated higher concentrations of several essential AAs, including histidine, isoleucine, threonine, and valine, with total essential AA content (223.2 mg/g DW) significantly higher than those on laboratory diet (166.6 mg/g DW) (P<0.05). The dietary influence was more significant than life stage in determining amino acid composition. Mātauranga Māori recognises that kawakawa leaves eaten by the kawakawa looper have enhanced medicinal properties. Supporting this knowledge, metabolomic analysis using rapid evaporative ionisation MS (REIMS) revealed distinct chemical changes in leaves eaten by the kawakawa looper (444 features, 16.08% differing from non-eaten leaves). These changes were unique and specific to insect herbivory, as artificially damaged leaves showed no significant differences from control leaves. The metabolomic response also varied between species, with the kawakawa looper and brindled bell moth showing the most distinct profiles (20.79% features differing), suggesting species-specific interactions between insects and kawakawa. This research provides the first comprehensive analysis of native Aotearoa New Zealand insects as a sustainable food source, integrating mātauranga Māori and Western scientific approaches. The findings establish a foundation for developing nutritious insect-based foods that align with cultural values and environmental sustainability, demonstrating the potential of native insects in addressing food security challenges in Aotearoa New Zealand and globally.Publication Embargo A retrospective analysis of climate impacts on Pinot noir wine quality – A New Zealand case study : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Wine and Viticulture(Lincoln University, 2024) Taylor, Peter KevinThe quality of Pinot noir is intricately linked to climatic conditions experienced in season, and in particular the influence of temperature within phenological stages. Many studies have modelled the impact of climatic parameters, including temperature, on wine quality with wine score often used as proxy. However, these approaches are limited to regional spatial resolution, with a single climate dataset applied to all vineyards. The aim of this research was to model the relationship between temperature-base climatic indicators to phenological stages and phases, creating a set of ecoclimatic indicators,and assessing Pinot noir quality at the single-vineyard scale against these indices. Utilising modelled temperature-related climate parameters, derived through thin-plate spline interpolation, for individually mapped vineyards in New Zealand, a climate record was constructed for Pinot noir vineyards for the vintages 2015 to 2022. This climate record was used to simulate phenological timing of flowering, veraison, and time to target sugar concentration as a proxy of ‘ripening’(defined as 210g/L), then to determine the influence of frosts, incidence of hot days and stress days (maximum temperature >25oC and >30oC respectively), and diurnal temperature range on Pinot noir quality using scores (100point scale) using individual linear, then multiple linear regression models. Both an increasing incidence of hot days and increasing diurnal temperature ranges were positively and significantly related to Pinot noir quality between both flowering and veraison and veraison to ripening. Conversely, the relationship between frosts and Pinot noir quality was convoluted by covariance with a regional effect leading to an inability to determine its influence on wine quality. This research has provided a novel platform for assessing at a very high spatial resolution the impacts of ecoclimatic indicators on the quality of Pinot noir. Potential applications of this research include modelling how future climate scenarios may impact wine quality, simulating potential impacts and phenological timing under climate change scenarios, and applications in training neural network models to predict potential quality based on weather data inputs.Item Open Access Analysis of bacterial and fungal communities and organic acid content in New Zealand lambic-style beers: A climatic and global perspective(Multidisciplinary Digital Publishing Institute (MDPI), 2025-02) Ohwofasa, Aghogho; Dhami, Manpreet; Winefield, Christopher; On, StephenBeer produced by autochthonous microbial fermentation is a long-established craft beer style in Belgium that has now been implemented commercially in New Zealand. We used a metabarcoding approach to characterize the microbiome of 11 spontaneously fermented beers produced by a single brewery in Oamaru from 2016 to 2022. Key organic acid concentrations were also determined. Both bacterial and fungal populations varied considerably between vintages and between individual brews produced in 2020. Similarly, for organic acids, the concentrations of L-malic acid, succinic acid, and L-lactic acid statistically differed from one vintage to another. Moreover, a correlation between the concentrations of certain organic acids and microbial composition was inferred by ordination analyses. Through reference to publicly available climate data, humidity and maximum temperature seemed to enhance the abundance of Penicillium and Hanseniaspora in beer microbiota. However, comparison with previously published studies of Belgian lambic beers, similar Russian ales, and publicly available temperature data from these regions showed that the microbial populations of these were relatively stable despite greater extremes of weather. Our results suggest that while climatic variables may influence microbial populations during beer making that employs autochthonous fermentation in New Zealand, such variation is not evident where similar beers are produced in facilities with a long-established history of production. These findings have implications for lambic-style beer production in the context of global climate change, notably where microbial populations may lack environmental adaptation.Item Open Access Differences in organic Pinot Noir wine production systems correlated with microbiome analysis, sensory characteristics and volatile composition(Elsevier, 2024-06-19) Ohwofasa, A; Tian, Bin; Torrico, Damir; Dhami, M; Winefield, Christopher; On, StephenThe action of microorganisms on grape must during the fermentation process contributes significantly to the organoleptic properties of wine. The influence of the environment on microbial growth and metabolism is also well recognized. Organic winemakers rely on indigenous yeasts to drive their fermentation processes, however there are few studies that examine the possible influence of environmental factors on fermentation, and on sensory attributes of the finished product. We previously used a community metabarcoding approach to analyse the microbiome associated with organic wine produced in two differing environmental systems; outdoors (vineyard) and indoors (winery). The resultant wine from both systems were then assessed for aroma composition using GC-MS, and sensory attributes by a group of wine experts. Possible correlations between the identified microbial populations and sensory attributes were investigated to determine potential drivers. The results confirm the crucial role of the yeast, Saccharomyces in the modification of wine aroma and flavour. Moreover, analysis of the output of differential gene expression analysis (DESeq2) showed that the genus Gluconobacter might influence the ‘Mouth feel’ (astringency/tannin) and taste (bitterness) attributes of wines. Some volatile compounds were uniquely associated with a single wine. This suggests that measured differences in microbial community composition might play roles in their synthesis. Collectively, these results contribute to understanding the interplay of the complex microbial community matrix present in ‘wild’ ferments in terms of sensory and chemical characteristics of wine.Item Restricted Investigating the preparation of hemp-protein isolate (HPI)(2024-07) Wu, Gaosheng; Kumar, Lokesh; Morton, James; Lee, HannahThe aim of this research is to investigate the preparation of hempprotein isolate (HPI) and its subsequent hydrolysis using 0.5%bacterial protease and 2% pepsin protease in order to address HPI's low solubility, resulting in the production of hemp proteinhydrolysates (HPH). Samples were extracted minutes,showing identical degrees of hydrolysis. Hemp protein hydrolyzed with bacterial protease (HPHB) enhanced oil absorption capacity andemulsifying capacity, while hemp protein hydrolyzed with pepsin (HPHP)demonstrated an increase in water absorption capacity. In addition,the effects of varying HPH concentrations on the functional and nutritional properties of corn starches were explored. The study involved mixing two types of HPH, with concentrations of 10% and 20%,respectively, with normal corn starch (NCS), waxy corn starch (WCS),and high amylose corn starch (HACS). The significant decrease in RDS values was around 22% with 20% HPHP in HACS. The highest increase in RSvalues was about 10% with 10%HPHB in WCS. 20% HPHP exhibited the highest antioxidant activity among the three different amylose content starches and 20%HPH exhibited a favorable amino acid profile characterized by HPLC analysis. This study contributes to a deeper understanding of the interactions between starch-protein hydrolysates and holds promise for the development of healthier, more sustainable,and innovative foods.Item Open Access Proximate composition, peptide characterization and bioactive properties of faba bean blanching water(Elsevier Ltd., 2025-01) Feng, Z; Morton, James; Maes, E; Kumar, Lokesh; Serventi, LucaFaba bean (Vicia faba L.) offers a rich nutritional profile with high protein content and abundant vitamins and minerals. Processing of faba beans for freezing requires blanching, yielding liluva (legume processing water), possibly containing leached macronutrients, with potential for upcycling. Past evidence has shown that legume processing water may be high in protein. Peptides generated from faba bean proteins during processing have been shown to have bioactivity and can, for example, inhibit HMG-CoA reductase. HMG-CoA reductase is rate-limiting in the biosynthesis of cholesterols and high cholesterol increases the risk of cardiovascular diseases. Thus, this study examined the composition of legume blanching water, analysed the peptides resulting from in vitro digestion and assayed HMG-CoA reductase inhibitory activity of liluva from faba beans sourced from two farms in Canterbury, New Zealand. Results showed that the blanching water contained around 1.7 g/100 mL solid content. These solids were approximately 30 % protein, 12 % water-soluble carbohydrates, 4 % dietary fibre, and 0.17 % ash. Mineral analysis showed high levels of potassium in macro minerals and zinc in trace minerals. Free amino acid analysis revealed high levels of arginine, alanine, asparagine, and glutamic acid, and low levels of methionine and tryptophan. Mass spectrometry analysis identified 111 and 72 endogenous peptides in farm 1 and 2 raw samples, respectively. Most of these peptides were derived from tripeptidyl-peptidase II and subtilisin-like protease. To understand potential bioactivity of these peptides, peptides were also analyzed after in vitro digestion. The resulting identified peptides indicated in silico predicted bioactivities such as anti-thrombotic, antioxidative, ACE dipeptidyl peptidase −III and −IV inhibition and HMG-CoA reductase inhibition activities. Further validation of the faba bean blanching water after in vitro digestion demonstrated approximately 67 % inhibition of HMG-CoA reductase activity, suggesting potential hypocholesterolemic properties. These findings suggest that faba bean blanching water may serve as a sustainable and functional ingredient with potential cholesterol-lowering effects in food production.Item Open Access Dietary bioactive compounds trigger distinct epigenetic and metabolic reprogramming in Lactobacillus acidophilus(Cold Springs Harbor Laboratory, 2024-08-18) Kong, Yanzhuo; Adejoro, Damola; Wescombe, Philip A; Winefield, Christopher; On, Stephen; Mitchell, Nadia; Subbaraj, Arvind; Saunders, Andrew; Maes, Evelyne; Chelikani, VenkataLactobacillus acidophilus ATCC 4356 (LA), a key probiotic in the human gut microbiota, offers several health benefits. While dietary bioactive compounds are known to influence gut microbiota, their specific mechanisms remain unclear. This study investigated how certain dietary bioactive compounds impact LA gene expression and metabolism. Results showed each compound produces unique transcriptional, metabolic, proteomic, and epigenetic profiles in LA. Notably, dietary compounds altered the epigenetic landscape through N4-methylcytosine (4mC) modification, a relatively underexplored form of methyl modification that may play a role in regulating gene transcription. For instance, genistein treatment up-regulated 76 genes and the down-regulated 130 genes in LA. A gene involved in mucus-binding proteins, crucial for bacterial adhesion, was up-regulated 38-fold, likely due to 4mC modifications. Additionally, the gene coding for the melibiose operon regulatory protein increased 78-fold, enhancing melibiose (a prebiotic) production with genistein, but only 1.1-fold with sodium butyrate. This study highlights the potential of dietary compounds for microbial metabolic engineering, offering a non-GMO method for modulating bacterial performance and other biotechnology applications.Item Restricted A gastrointestinal parasite infection model for chronic stress in livestock and its impact on meat quality(ACK 2024, 2024-11-13) Lee, Hannah; Morton, JamesLivestock stressors are known to have an impact on both animal welfare and meat quality. As a model of acute stress, we have previously demonstrated the impact of pre-slaughter simulated mustering on several important meat quality markers in lamb, including high pH [1, 2]. To examine a chronic stressor in livestock, we have adapted a model of a sub-clinical infection with gastrointestinal nematode(GIN) parasite infection in sheep. Six month old ram lambs were challenged with a mixed infection of Trichostrongylus colubriformis and Teladorsagia circumcincta (Treatment group, n=6), which are common gastrointestinal parasites frequently encountered in pasture, and compared with those without parasites (Control, n=6) (AEC2023-71). The goal is to understand how parasite infection can impact on inflammatory response as a proxy for animal welfare, along with determining if parasite infection has an impact on meat quality markers. We will also use an emerging metabolomics method, rapid evaporative ionisation mass spectrometry, to provide complementary analytical information on changes to organ and meat metabolite and lipid composition. This data will contribute towards defining and designing further investigations on chronic stressors in livestock. In future, characterised biomarkers of stressors could be used for enhancing animal welfare and confirm the relationship between minimising pre-slaughter stressors and improving the consistency of meat quality.