The impact of long-term culture on primary bovine myoblasts : implications for cultivated meat production and allergenicity
A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at University of Canterbury
(2025) Trlin, Hamish John Francis
With global demand for meat products growing and traditional methods of production nearing their limits, alternative methods of meat production are required. While cultivated meat is a promising alternative to traditional meat, information about the impact of long-term culture on cultivated cells is lacking. Here, I compare the use of high impact methods of stem cell isolation and enrichment in cultivated meat research and product development to alternative low impact methods, define the impacts of isolation and long-term cell culture on the allergenicity of cultivated cells, and determine the broader impact of long-term cell culture on protein abundance and modification in cultivated cells.
Chapter 2 demonstrates that enzymatic digestion and fluorescence-activated cell sorting remain the preferred methods for myoblast isolation and enrichment. While whole tissue explant isolations and collagen pre-plating enrichment have theoretical benefits as low impact alternatives, these methods were unable to produce sufficiently pure populations of myoblasts for use in long-term cell culture. Chapter 3 then reveals differences in the relative abundance or detection of allergens in native and cultured cells, demonstrating why allergenic equivalence should not be assumed. Significant reductions in the abundance of major protein allergens Bos d 6 and Bos d 13 suggest the allergenic potential of cultivated beef meat may be reduced compared to traditional beef meat. However, an increased detection α-Gal in cultured cells, alongside an increased abundance of currently insignificant protein allergens ENO1, ATP5PO, and COL1A2, suggests that allergenicity may be increased. Finally, Chapter 4 identifies significant, ongoing differences in the proteomes of primary bovine myoblast proteomes throughout the duration of long-term culture. More than 70% of proteins are shown to be significantly differently abundant following short or long-term culture, accompanied by changes in the general patterns of glycan modification. These results clearly demonstrate that culture duration has a significant effect on primary stem cell populations.
This thesis provides evidence that allergens are differently abundant in native and cultivated cells, calling to question the present assumption of allergenic equivalence between traditional and cultivated meats. While the clinical significance of these results have yet to be determined, they highlight a need for the optimisation of myoblast isolation and culture to reduce differences between native and cultured cells. Minimising these differences is likely to improve the characteristics of primary cultivated cells, thus cultivated meat, while reducing allergenic potential.
Three essays on advancing modelling of sustainable rural land use change decision making in Aotearoa New Zealand
A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2025) Wang, Le
Understanding the processes driving the development of niche industries is crucial for achieving sustainable agricultural transitions. In Aotearoa New Zealand (NZ), niche agricultural products, primarily from horticultural industries, have long existed but have struggled to evolve into mainstream agricultural systems. The total land area dedicated to these alternative systems remains small compared to pastoral farming, such as dairy and sheep/beef farming. Since the 1980s, the expansion of dairy farming and a large reduction in sheep number have dominated agricultural land use change in Aotearoa NZ. However, the last decade has witnessed a shift in some of the most intensively farmed dairy regions, such as Canterbury, Marlborough, and Southland, where dairy farming has declined in total area while horticultural land use has grown. These divergent trends provide an opportunity to investigate the dynamics of rural land use change and the potential for transitioning toward more sustainable agricultural systems. This thesis explores the drivers, dynamics, and patterns of rural land use change in Aotearoa NZ through three interconnected essays, each addressing critical aspects of the transition process. Essay One employs machine learning methods, particularly artificial neural networks (ANNs), to identify and evaluate the key drivers of sustainable land use transitions. Using data from the 2021 Rural Decision Makers Survey, this essay highlights the importance of farmer and farm characteristics, values, and demographics in influencing land use decisions. Essay Two develops an opinion dynamics model to examine how farmers’ attitudes towards land use change evolve within agricultural communities. The model captures the role of social networks and peer influence in shaping decision-making processes, offering insights into mechanisms of consensus or polarization among farmers. Essay Three integrates the methodologies and findings from the first two essays into an agent-based modelling (ABM) framework. This essay simulates rural land use transitions in Canterbury over a 25-year period, considering farm-level heterogeneity, social interactions, and real-world geographical characteristics. The results reveal key patterns of land use change, including a gradual shift from sheep and beef farming to horticulture, while dairy farming shows limited transition.
Collectively, the three essays provide a comprehensive framework for understanding and modelling sustainable land use change from the perspective of decision-makers. This research contributes to the literature on agricultural land use by combining machine learning, social network analysis, and agent-based modelling to offer robust evidence and actionable insights. The findings highlight opportunities for fostering sustainable land use transitions and inform policies and interventions to support alternative land use systems in Aotearoa NZ.
Understanding the bioaccessibility of grape phenolics in association with milk proteins
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
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 Wickramanayake
Embargoed until March 2027
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 Ohorere
With 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.