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Massey Research Online is an open access digital archive of the research and scholarship of Massey University and is jointly managed by the University Library and Information Technology Services.

Massey Research Online contains research theses and research outputs including published work by Massey University students and academic staff as well as peer-reviewed material not published elsewhere. In the case of previously published research outputs all requirements of copyright owners are observed.

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Heat-induced interactions between microfluidized hemp protein particles and caseins or whey proteins
(Elsevier Ltd, 2025-01) Ma S; Ye A; Singh H; Acevedo-Fani A
The rising demand for sustainable proteins leads to increased interest in plant proteins like hemp protein (HP). However, commercial HP's poor functionality, including heat aggregation, limit its use. This study explored the heat-induced interactions of hemp protein particles (HPPs) with milk proteins, specifically whey proteins and caseins. Using various analysis techniques-static light scattering, TEM, SDS electrophoresis, surface hydrophobicity, and free sulfhydryl content-results showed that co-heating HPPs with whey protein isolate (WPI) or sodium caseinate (NaCN) at 95 °C for 20 min reduced HPPs aggregation. HPPs/WPI particles had a d4,3 of ∼3.8 μm, while HPPs/NaCN were ∼1.9 μm, compared to ∼27.5 μm for HPPs alone. SDS-PAGE indicated that whey proteins irreversibly bound to HPPs, through disulfide bonds, whereas casein bound reversibly, possibly involving the chaperone-like property of casein. This study proposes possible mechanisms by which HPPs interact with milk proteins and impact protein aggregation. This may provide opportunities for developing hybrid protein microparticles
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The Scoop on SCOBY (Symbiotic Culture of Bacteria and Yeast): Exploring Consumer Behaviours towards a Novel Ice Cream
(MDPI (Basel, Switzerland), 2023-09) Mehta A; Serventi L; Kumar L; Torrico DD; Cox DN
With the growing demand for sustainable practises, the food industry is increasingly adopting circular economy approaches. One example is recycling the symbiotic culture of bacteria and yeast (SCOBY) used in kombucha fermentation to create value-added products. However, consumer acceptance of such novel products remains unclear. To address this, the present study examined consumer attitudes towards ice cream made with SCOBY as an ingredient and how this affected their intention to consume it. Drawing on the theory of planned behaviour (TPB) and additional constructs such as emotions and food neophobia, an online survey was conducted with New Zealand consumers (N = 170). Results showed that the TPB constructs significantly predicted the intention to consume SCOBY ice cream. Moreover, by adding emotions to the constructs, the model's explanatory power was enhanced. Attitudes, subjective norms, and emotions were the main predictors of intention, which in turn was found to be the main predictor of behaviour. Participants' beliefs about the safety and taste of SCOBY ice cream were significantly correlated with their intention and behaviour, as were the opinions of nutritionists/dietitians, friends, and family. The model accounted for 21.7% of the variance in behaviour and 57.4% of the variance in intention. These findings can be used to plan marketing strategies related to waste-to-value-added products such as SCOBY ice cream.
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Survey of Handlers of 158 Police Dogs in New Zealand: Functional Assessment and Canine Orthopedic Index.
(Frontiers Media S.A., 2019-04-16) Baltzer WI; Owen R; Bridges J; Levine D
Objectives: To determine the functional assessment (FA) of fitness and Canine Orthopedic Index (COI) scores of 158 police dogs. The hypothesis was the dogs would have excellent fitness and no evidence of orthopedic disease regardless of age as reported by the handlers. Study Design: Observational, prospective study. Sample Population: Handlers of dogs >1 year of age in active duty or breeding/active duty. Methods: COI and FA questionnaires were completed via e-mail. Fisher's Exact test for count data assessed scores by age group (<2 years, 2–5 years, >5 years); Wilcoxon Signed-rank test correlated COI parameters (stiffness, function, gait, quality of life) to FA. Results: The dogs were 3.2 ± 2.4 (mean ± standard deviation) years-old, 96% were German Shepherds and 111 were male. 32% of dogs could hold the “Hup” position for no longer than 4 s and 8% frequently had difficulty with this task. Difficulty jumping into vehicles occurred in 1/3 of the dogs. Overall FA was impaired in 20% (score >8), abnormal in 15% (score = 5–7), and reduced (score = 1–4) in 36% of dogs. Only 29% had normal function (FA score = 0) and these were significantly younger (2.8 ± 1.7 years, p < 0.05) than impaired dogs (6.6 ± 2.2 years). COI stiffness score was abnormal in 37% (3.3 ± 2.2) and gait was abnormal in 41% (5.4 ± 4.0). Quality of life (QOL) was excellent in 69% of dogs. Stiffness for the <2 year-old group was 0.2 ± 0.8, for the 2–5 year-old group was 1.1 ± 2.0 and for the >5 year-old group was 3.2 ± 2.4. Gait score for the <2 year group was 0.8 ± 2.2, and for the 2–5 year group was 1.9 ± 3.2 and for the >5 year group was 6.0 ± 4.3. Quality of life was close to excellent for the <2 year-olds (0.3 ± 1.1) and 2–5 year-olds (0.8 ± 2.0) but the >5 year-olds scored higher (3.0 ± 2.5). Only the COI gait score correlated with the FA score (p = 0.30). Conclusions and Clinical Relevance: Police dogs were reported by handlers to have good to excellent QOL, however, increasing age was associated with declining FA and COI scores.
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Simultaneous Whole-Chamber Non-contact Mapping of Highest Dominant Frequency Sites During Persistent Atrial Fibrillation: A Prospective Ablation Study
(Frontiers Media S.A., 2022-03-16) Chu GS; Li X; Stafford PJ; Vanheusden FJ; Salinet JL; Almeida TP; Dastagir N; Sandilands AJ; Kirchhof P; Schlindwein FS; Ng GA; Ng FS
PURPOSE: Sites of highest dominant frequency (HDF) are implicated by many proposed mechanisms underlying persistent atrial fibrillation (persAF). We hypothesized that prospectively identifying and ablating dynamic left atrial HDF sites would favorably impact the electrophysiological substrate of persAF. We aim to assess the feasibility of prospectively identifying HDF sites by global simultaneous left atrial mapping. METHODS: PersAF patients with no prior ablation history underwent global simultaneous left atrial non-contact mapping. 30 s of electrograms recorded during AF were exported into a bespoke MATLAB interface to identify HDF regions, which were then targeted for ablation, prior to pulmonary vein isolation. Following ablation of each region, change in AF cycle length (AFCL) was documented (≥ 10 ms considered significant). Baseline isopotential maps of ablated regions were retrospectively analyzed looking for rotors and focal activation or extinction events. RESULTS: A total of 51 HDF regions were identified and ablated in 10 patients (median DF 5.8Hz, range 4.4-7.1Hz). An increase in AFCL of was seen in 20 of the 51 regions (39%), including AF termination in 4 patients. 5 out of 10 patients (including the 4 patients where AF termination occurred with HDF-guided ablation) were free from AF recurrence at 1 year. The proportion of HDF occurrences in an ablated region was not associated with change in AFCL (τ = 0.11, p = 0.24). Regions where AFCL decreased by 10 ms or more (i.e., AF disorganization) after ablation also showed lowest baseline spectral organization (p < 0.033 for any comparison). Considering all ablated regions, the average proportion of HDF events which were also HRI events was 8.0 ± 13%. Focal activations predominated (537/1253 events) in the ablated regions on isopotential maps, were modestly associated with the proportion of HDF occurrences represented by the ablated region (Kendall's τ = 0.40, p < 0.0001), and very strongly associated with focal extinction events (τ = 0.79, p < 0.0001). Rotors were rare (4/1253 events). CONCLUSION: Targeting dynamic HDF sites is feasible and can be efficacious, but lacks specificity in identifying relevant human persAF substrate. Spectral organization may have an adjunctive role in preventing unnecessary substrate ablation. Dynamic HDF sites are not associated with observable rotational activity on isopotential mapping, but epi-endocardial breakthroughs could be contributory.
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Bovine dairy complex lipids improve in vitro measures of small intestinal epithelial barrier integrity
(PLOS, 2018-01-05) Anderson RC; MacGibbon AKH; Haggarty N; Armstrong KM; Roy NC; Brandner JM
Appropriate intestinal barrier maturation is essential for absorbing nutrients and preventing pathogens and toxins from entering the body. Compared to breast-fed infants, formula-fed infants are more susceptible to barrier dysfunction-associated illnesses. In infant formula dairy lipids are usually replaced with plant lipids. We hypothesised that dairy complex lipids improve in vitro intestinal epithelial barrier integrity. We tested milkfat high in conjugated linoleic acid, beta serum (SureStart™Lipid100), beta serum concentrate (BSC) and a ganglioside-rich fraction (G600). Using Caco-2 cells as a model of the human small intestinal epithelium, we analysed the effects of the ingredients on trans-epithelial electrical resistance (TEER), mannitol flux, and tight junction protein co-localisation. BSC induced a dose-dependent improvement in TEER across unchallenged cell layers, maintained the co-localisation of tight junction proteins in TNFα-challenged cells with increased permeability, and mitigated the TEER-reducing effects of lipopolysaccharide (LPS). G600 also increased TEER across healthy and LPS-challenged cells, but it did not alter the co-location of tight junction proteins in TNFα-challenged cells. SureStart™Lipid100 had similar TEER-increasing effects to BSC when added at twice the concentration (similar lipid concentration). Ultimately, this research aims to contribute to the development of infant formulas supplemented with dairy complex lipids that support infant intestinal barrier maturation.