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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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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.Item Open Access Peptidomic analysis of anionic oat intestinal peptides(2023-07-04) Gong, Xi; Lee, Hannah; Brennan, Margaret; Middleditch, Martin; Morton, JamesMany studies have focused in recent years on the functional and nutritional properties of proteins in cereal and the bran and the bioactive attributes of peptides derived from these proteins. In vitro digestion model in combination with anion exchange chromatography isolates the cereal anionic intestinal peptides which, unlike cereal hydrophobic peptides, has not been proven to strongly relate to the bioactivity of peptides. The aim of my PhD project is to identify the bioactive anionic peptides derived from the storage protein of cereal bran and to assess their bioactivity. The protein was extracted from oat bran, wheat bran and barley and was then subjected to in vitro digestion model. The intestinal digesta of oat bran protein showed highest overall antioxidant and ACE inhibitory activity and was fractionated by anion exchange chromatography, and the fractions of which with highest antioxidant and ACE inhibitory activity were selected for sequencing by R-HPLC-MS/MS. The peptides in the fraction candidates were identified. In addition, the most abundant peptides in the fraction candidates were identified and the relation of those abundant peptides to bioactivity was evaluated. For future perspective, the ACE inhibitory peptide candidates will be analysed by molecular docking. The peptide will be selected for synthesis and assayed to confirm the discovery of the novel peptides. Meanwhile, it is interesting to bring the novel peptides to cell-line works and in vivo.Item Restricted Design and analysis of novel 3D printed foods with re-purposed animal and plant proteins(2023-07-03) Peddisetti, Sahiti; Lee, Hannah; Bentley, Kelly-Anne; Pope, Isobel; Hampton, Jessica; Kaur, Lovedeep; Singh, Jaspreet; Morton, JamesFood Transition 2050 describes the need for New Zealand to diversify its food products. This has led to an increased interest in evaluating new food applications for animal, plant, fungal and microbial proteins. One of the approaches to increase available protein is to reduce food wastage and fully utilize existing animal and plant-based proteins by improving the functional and nutritional value of side streams from the food industry. Often these have either poor texture or visual appeal. 3D food printing technology offers the opportunity to turn these side streams into complex shaped foods with increased functional and nutraceutical value. With the insights on 3D food printing technology and the newly installed in Lincoln University, The current project uses 3D Foodini food printers (manufactured by Natural Machines) to develop the tools and prototype processes that will allow the industry to gain greater value from the NZ resource base by producing new-to-NZ protein ingredients and foods. Our team has successfully established animal protein based (meat or dairy), pea protein based and hybrid (peameat; pea-dairy; pea-dairy-meat) 3D printed foods, and then determined their textural and rheological properties of these 3D printed protein constructs. These attractive 3D printed soft-textured protein-rich products will be particularly useful to people with special dietary requirements like dysphagia and geriatrics.Item Restricted The effect of farmyard stress on meat quality: A model for predictive biomarkers of meat pH(2023) Lee, Hannah; Ross, Alastair; Morton, JamesBackground/Objectivs: High pH meat is frequently associated with poor shelf-life and eating quality, and pH is a commonly used marker for meat quality. Early detection of high pH lamb is desirable and can improve meat quality control. Due to the variability in the occurrence of high pH at meat processing plants in New Zealand, there is a need for reproducible models that allow the study of abnormal pH in meat. We devised a pilot trial using standardised farmyard stress to produce high pH meat. Method: This experiment compared lambs exposed to some of the normal pre-slaughter stress factors within a New Zealand pastoral system with a control group with minimal pre-slaughter stress. It used two groups of 10 lambs, held in the pasture paddock next to the abattoir. The 10 “low stress” animals were kept quietly in pens prior to slaughter while the second group of 10 animals were exercised by moving with a dog for 5-10 minutes every hour for 4 hours prior to slaughter (“moderate exercise stress”). Rapid metabolomics (rapid evaporative ionisation mass spectrometry, REIMS) analyses were carried out on the immediate post-slaughter samples. The carcasses were aged and meat quality measurements were taken at different post mortem time points: pH (at 1.5 h, 24 h), colour (at 4 days), cooking loss and shear force (at 7/8 days). Results: The pH declined significantly over the 24 h post-slaughter in all muscles. At 1.5 h post-mortem, there was no significant difference in the average pH of muscles among non-exercised (pH 6.650, N=100) and exercised groups (pH 6.683, N=99). When the pH of two different fibre types was compared as an early sign of pH response to pre-slaughter exercise stress, the slow/oxidative muscle types had significantly higher pH than the same muscle types from non-exercised group (p=0.011). This was not seen in fast/glycolytic fibre muscles. At 24 h post-mortem muscles, the pH of the muscles from exercised group (N=99, pH 6.14) was significantly higher in comparison to the muscles from non-exercised (N=100, pH 5.85, p=0.000). Exercise stress also resulted in differences in other meat quality measurements. Colour, cooking loss and shear force of some muscles were changed after exercise stress. REIMS analysis found clear metabolite-based differences between muscles from exercised and control sheep, and between muscles. Conclusion: We have developed a model for generating high pH lamb based on farmyard pre-slaughter stress. This resulted in changes to several important meat quality markers. Samples from this trial have been used for fingerprinting mass spectrometry to identify new potential predictive markers of high ultimate pH. This simple farmyard stress model is a useful tool for research on high pH meat under controlled yet realistic conditions, and follow up validation trials has confirmed the reproducibility of this model. In future, biomarkers of high pH in the meat could be used for enhancing animal welfare and confirm the relationship between minimising pre-slaughter stress and improving the consistency of meat quality.Item Open Access Nearly 50% of researchers quit science within a decade, huge study reveals (women in the science field too)(2024) Lee, HannahPresentation given at AKC 2024 - Women's Scientists Forum.Item Open Access Disease prediction for parasite: Gastrointestinal nematode infection as a model for the impact of chronic stress on meat qualityLee, Hannah; Ross, Alastair; Greer, Andrew; Slow, Sandy; Morton, JamesPresentation given at the AgResearch & Meat Industry Association Meat Innovation Workshop, 26 March 2024.Item Open Access Changes in total soluble solids concentration, fruit acidity, and yeast assimilable nitrogen in response to altered leaf area to fruit weight ratio in Pinot noir(The International Viticulture and Enology Society (IVES), 2024) Assefa, MK; Creasy, GL; Hofmann, RW; Parker, AmberThe increasing consumer demand for lower alcohol wine and the need to mitigate against a warming climate presents new challenges for winegrowers and the desire to produce grapes with lower total soluble solids (sugar) or earlier harvesting, while preserving other wine compounds and attributes, particularly for varieties intended for red wine production. We investigated how reducing vine leaf area through shoot trimming and leaf removal, applied at different severities and timings to modify the leaf area to fruit weight (LA) ratio, affects fruit composition for producing lower alcohol quality Pinot noir wine. Shoot trimming treatments (half canopy, H in 2015/16 and 2016/17, and quarter canopy, Q in 2016/17 by alternately removing leaves after trimming shoots to half) were applied shortly before veraison (V-, E-L 34), during veraison (V, E-L 35) and post-veraison (V+, E-L 36) in three different vineyard locations (Marlborough, Canterbury and Central Otago, New Zealand). Untrimmed vines served as the control. Lateral shoots were removed during treatment application, and regrowth was removed to maintain a consistent leaf area. Results showed that reducing the LA:FW ratio delayed the accumulation and concentration of total soluble solids (reduction of 1.0 to 2.7 °Brix) at harvest in all trimmed vines over both seasons. Berry weight, malic acid concentration, titratable acidity, and pH at harvest were unaffected by trimming. At target TSS levels of 18 °Brix (10 % ethanol, v/v) in the Marlborough vineyard and 20 °Brix (11 % v/v) in the Central Otago vineyard, V+ vines showed malic acid and titratable acidity levels comparable to the control. At the Canterbury vineyard, these parameters remained similar across all treatments at 16 °Brix (8.9 % v/v). Yeast-assimilable nitrogen concentration increased (188 to 411 mg/L) in early trimmed vines. At Central Otago, roots showed lower carbohydrate reserves across all trimming treatments, likely due to the high yield at the site, while at Canterbury, trimming did not result in significant differences in carbohydrate reserves, likely due to the low yield at the site. At the Marlborough vineyard, vines trimmed early and more severely had less starch in their roots, while HV+ vines maintained similar levels of starch to controls. In conclusion, halving the canopy post-veraison (HV+, LA 0.70 m²/kg as observed in Marlborough) could be considered a viable viticultural option to lower sugar accumulation, thereby reducing potential alcohol content, without affecting titratable acidity and pH. This practice offers significant potential for adapting to a warming climate and producing lower alcohol Pinot noir wines in a sustainable manner.Item Open Access Identification of the best viticultural areas by spatial optimisation. Application in New Zealand South Island in the context of climate change(The International Viticulture and Enology Society (IVES), 2024) Hamon, Baptiste; Thibault, Jeanne; Tissot, Cyril; Parker, Amber; Quénol, HervéThe global winegrowing sector is under pressure due to the effects of global climate change. This is particularly true for New Zealand, where the wine industry is limited to a few regions. This study focuses on the South Island of New Zealand. It uses the Multi-objective Optimisation for Agrosystems (MOA) model to (i) investigate how potential exposure to climate risks and phenological stages will evolve under climate change, (ii) assess the suitability of current vineyards for viticulture in the future, and (iii) investigate potential emerging areas favourable for viticulture. The results show that a significant shift in the phenological stages of veraison and ripeness can be expected in the future due to the warming of the South Island of New Zealand. The projected phenological stages advancement is around one week in the near term for both Shared-Socioeconomic Pathways studied (SSP2-4.5 and SSP5-8.5) and is more than three weeks and one month in long-term for SSP2–4.5 and SSP5-8.5 respectively. A regional to local increase in frost risk (Canterbury, Otago, and Southland) and a slight increase in disease risk (especially on the coast) are also projected in the future, while the South Island of New Zealand is not expected to be affected by heatwaves. The results show that Marlborough, New Zealand's most important winegrowing region, will continue to be one of the best areas for viticulture in the 21st century. On the other hand, new winegrowing opportunities are expected to emerge inland and southwards. Overall, this study contributes to the understanding of the impact of climate change on the New Zealand wine industry and emphasises the need to adapt to changing climate conditions. It also provides insights into the future suitability of vineyards and identifies potential expansion areas for the New Zealand viticulture sector.Item Open Access Effect of ultrasonic-pretreatment on soaking kinetics, nutritional, anti-nutritional, and functional properties of guar seeds(Elsevier Ltd., 2024-12-01) Kheto, Ankan; Chaudhari, Aditi; Manikpuri, Sakshi; Sehrawat, Rachna; Gul, Khalid; Kumar, Lokesh; Khan, Khursheed AlamThe study aimed to understand how varying the amplitude (25, 50, and 75%) and duration (15, and 30 min) of ultrasonic (US) pretreatment affected the soaking kinetics, nutritional, anti-nutritional factors (ANFs), in-vitro protein digestibility, and functional properties of guar seeds (GS). The GS required ∼1080 min to hydrate and absorbed ∼4.66 times higher moisture content. The US pretreatment reduced ∼55.55% of soaking duration compared to control. Soluble protein and fat content was significantly (p < 0.05) varied with US-treatment conditions. The water absorption capacity and foaming capacity of GSF samples gradually improved. Expect 75% amplitude, bioactive compounds in GSF begin to rise with longer duration and amplitude than control. Noticeable reduction of ANFs was observed in US-pretreated soaked GSF samples. As observed from FTIR and XRD analysis, US pretreatment might have reorganized structure orientation. Meanwhile, in-vitro protein digestibility gradually increased with US amplitude and duration. From multivariant analysis, 75% amplitude-15 min of US pretreatment may be a better option for shorter soaking time, and lesser ANFs. Therefore, US pretreatment could be helpful in increasing the protein extraction yield of GS. Furthermore, US-pretreated soaked GS might be useful to formulate bakery items.Item Open Access Effects of retained node numbers on berry maturity and yield components of cane-pruned Sauvignon blanc(The International Viticulture and Enology Society (IVES), 2024-07) Epee, PTM; Schelezki, Olaf; Trought, MCT; Werner, A; Hofmann, RW; Almond, Peter; Charters, Stuart; Parker, AmberCane pruning is used in most New Zealand Sauvignon blanc vineyards to manage yield, vine balance (relationship between vegetative growth and fruit growth) and fruit primary and secondary metabolites. The source–sink ratio (TLA/FM—total leaf area to fruit mass or ELA/FM—exposed leaf area to fruit mass), the fruit mass to pruning mass (FM/PM), the fruit mass to cane mass (FM/CM) and fruit composition provide an assessment of the vine performance and balance. The interpretation of these metrics (i.e., TLA/FM, ELA/FM, FM/PM, FM/CM) requires their comparison with known optimal ranges specific to cultivars, locations and growing conditions. More often, such context-and cultivar-specific optimal ranges do not exist, thus warranting research to investigate them. To understand the influence of retained node numbers on the vegetative and fruit development of Sauvignon blanc, grapevines were pruned across three vineyard sites (two in Marlborough—Site 1 and 2, and one in Waipara— Site 3) over two growing seasons, retaining 10, 20, 30, 40 and 50 nodes on one to four canes (each cane carrying ten nodes, with 50-node vines carrying on average 12.5 nodes on each of the four canes). The accumulation of soluble solids (TSS) generally increased at lower node numbers and vine yields, reflecting an increase in ELA/FM, with 50-node vines having the least TSS concentration at harvest. The average berry mass, titrable acidity (TA) and pH were unaffected by node numbers over the two seasons. A low source–sink ratio induced by high node numbers not only reduced the vine capacity to ripen the current crop but also reduced the following season’s bunch number per shoot (from 1.8 to 1.6 bunches per shoot; p < 0.05), average bunch mass (from 82.0 ± 6 g to 67.7 ± 3 g; p < 0.01) and bunch mass per shoot (from 153.5 ± 15 g to 106.7 ± 9 g; p < 0.05). When compared to 50-node vines, 10-node vines had a two-fold increase in the average cane mass (from 30.1 ± 3.9 g to 69.2 ± 8.7 g; p < 0.001) and average old cane mass (from 82.4 ± 6.9 g to 163.8 ± 21 g; p < 0.001). The ELA/FM and TLA/FM required for optimal TSS accumulation were 0.75 m² kg-1 and 2.0 m² kg-1, respectively, across all sites. A source–sink ratio above these values resulted in high average cane mass and average old cane mass (an indication of excess vigour), while lower values indicated reduced vigour and slowed TSS accumulation. This research provides useful optimal ranges to compare and interpret vine balance metrics measured at those sites.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.