Journal Articles

Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915

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Author: search.filters.author.Giezenaar C

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    Exploring the association of personal factors with affective responses to plant-based meat alternatives with consideration of their perceived similarity to meat
    (Elsevier Ltd, 2025-12-01) Giezenaar C; Mehta A; Orr RE; Godfrey AJR; Foster M; Hort J
    Plant-based meat alternatives (PBMAs) have gained popularity as perceived sustainable replacements for meat, yet consumption remains limited. Understanding how personality traits shape PBMA consumption experience is therefore essential. This study surveyed 140 New Zealand consumers, assessing behavioural traits and attitudes related to willingness to reduce meat consumption/increase PBMA consumption. Participants completed tasting sessions evaluating commercially available PBMA products, based on flavour, texture, overall liking and emotions evoked, and sample perceived similarity to meat. Participants reported their demographic information, dietary habits, and frequency of meat and PBMA consumption. Results showed that higher social status derived from PBMA consumption were linked with higher liking ratings and citation proportion of ‘hungry’ for PBMAs. However, high negative attitude towards vegetarianism/veganism was linked to higher citation proportion for ‘unhappy’ for wholefood samples, while lower citation proportion for ‘unhappy’ for somewhat meat-like samples. High meat attachment was associated with lower perceived similarity to meat in both meat-like and somewhat meat-like samples. Additionally, the high meat consumption group reported lower texture and overall liking for meat-like samples. High variety seeking consumers (VARSEEK scores) were positively associated with flavour and overall liking for wholefood samples. Based on dietary groups, meat avoiders, generally driven by environmental and animal welfare concerns, reported more negative emotions such as ‘unhappy’ when tasting wholefood PBMAs compared to omnivores and flexitarians, despite their strong ethical and environmental motivations. The research highlights the impact of consumer behavioural traits and attitudes on their PBMA perception and acceptance, providing valuable insights for improving product development.
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    Perception and acceptance of high seaweed content novel foods (Ulva spp. and Undaria pinnatifida) across New Zealand and Singaporean consumers
    (Elsevier BV, amsterdam, 2024-12) Chen A; Lim AJ; Lin JWX; Oh G; Teo PS; Bowie D; Deb-Choudhury S; Samuelsson LM; Chan JCY; Ng SB; Foster M; Giezenaar C; Hort J
    Edible seaweeds are gaining global popularity as nutritious and sustainable food sources, extending beyond Asian into Western diets. To investigate consumer perception and acceptance of high seaweed content foods, two novel products, seaweed dumplings and pasta, were developed using the mixture of Ulva spp. and Undaria pinnatifida as a primary ingredient. Consumer evaluations were conducted in New Zealand (NZ, n = 157) and Singapore (SG, n = 176). Results showed low overall liking and willingness to purchase for both products in each country, though NZ consumers rated them more positively in terms of liking, healthiness and sustainability than SG consumers. Willingness to purchase was positively correlated with ratings of liking, healthiness, and sustainability. Emotional responses differed by country and product, with more NZ participants reporting positive emotions (e.g., pleased, happy, hopeful and loving) and dumplings evoking more activate emotions (e.g., energetic, shocked and amazed). Umami taste enhanced overall liking in both countries, while slimy texture (NZ) and fish-like flavour (SG) decreased overall liking. These results underscore the current challenges in consumer acceptance of high seaweed content novel foods, but also highlight cross-cultural differences that can guide the development of seaweed-based foods in global markets.
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    Effects of Different Protein Sources on Amino Acid Absorption and Plasma Appearance of Tryptophan, Large Neutral Amino Acids, and Tryptophan Metabolites in Pigs
    (Elsevier Inc on behalf of American Society for Nutrition, 2024-07-15) Giezenaar C; Montoya CA; Kreutz K; Hodgkinson S; Roy NC; Mace LJ; Fraser K; Fernstrom JD; McNabb WC; Moughan PJ
    BACKGROUND: Absorption of tryptophan (TRP) across the gut epithelium is potentially modulated by competing large neutral amino acids (LNAAs), which could affect the appearance of TRP and its metabolites in the bloodstream. OBJECTIVES: This study aimed to determine, in a growing pig model of an adult human, the absorption of TRP and other LNAAs from the gastrointestinal tract, and plasma appearance of TRP, LNAAs, and TRP metabolites, in response to dietary proteins varying in TRP content. METHODS: Pigs were adapted for 7 d to each of 4 diets that differed in their protein source and TRP content: 1) alpha-lactalbumin (AL; 9.95 mg TRP/g diet DM), 2) whey protein (6.59 mg TRP/g), 3) casein (3.73 mg TRP/g), or 4) zein (0.14 mg TRP/g). On day 8, pigs were euthanised after a 12-h fast (baseline), or 1, 2, 3, 4, or 6 h after they received a test meal consisting of 45 g protein, or a protein-free meal (n = 6 pigs at each time in each meal group). Tryptophan and LNAA absorption from the small intestine, and appearance of TRP, LNAAs, and TRP metabolites (melatonin, serotonin, kynurenine pathway metabolites), in the portal vein and systemic circulation, were determined. RESULTS: AL intake resulted in sustained elevated plasma TRP concentrations after an overnight fast. The amount of TRP absorbed was dose-dependently related to protein TRP content (P = 0.028), with fastest rates for pigs fed AL (371 mg/h). Portal and systemic plasma TRP, TRP/LNAA, and the TRP metabolites were highest (P ≤ 0.05) after AL intake, and remained above baseline levels for ∼4 h postprandially. Absorption rates of TRP correlated with postprandial plasma TRP and TRP metabolites (P ≤ 0.05). CONCLUSIONS: In adult humans, postprandial plasma TRP and TRP metabolite concentrations can likely be modulated by the TRP content of the meal.
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    Motivators and barriers to plant-based product consumption across Aotearoa New Zealand flexitarians
    (Elsevier Ltd, 2024-08) Weerawarna N.R.P. M; Giezenaar C; Coetzee P; Godfrey AJR; Foster M; Hort J
    Limited knowledge exists concerning Aotearoa New Zealand (A-NZ) flexitarians and their respective motivators and barriers towards consumption of novel plant-based products (PBPs) heralded as aids for dietary meat reduction. This study aimed to determine if A-NZ flexitarians, who have tried novel PBPs, can be segmented based on different motivators and barriers to meat reduction and PBP consumption, if the consumer profile of the different segments varies according to identified gender, generation group, neophobia and meat and PBP consumption frequency. It also aimed to identify sensory characteristics novel PBPs need to possess to be attractive to A-NZ flexitarians and if these vary across segments. PBP-consuming flexitarians (n = 584), stratified according to age (Millennial/Gen X), identified gender and meat consumption frequency, completed an online survey regarding a) their level of agreement regarding statements related to factors driving PBP consumption and flexitarianism in general, and b) their satisfaction with the sensory experience of consuming current PBPs. ‘Tastes good’ was the top-rated factor for selecting PBPs for all consumers, but most were dissatisfied with the sensory characteristics of current PBPs. K-means cluster analysis identified three flexitarian segments based on similarities and differences in key motivations and barriers to consume PBPs. Attitudes and behaviours related to nutrition/health, and social status attained from eating both PBPs and meat products, accounted for most variation across the respondents. Overall, higher food neophobia was associated with higher PBP consumption, suggesting that neophobia itself is not necessarily a barrier to PBP consumption in A-NZ flexitarians. Improving the sensory profiles of PBPs whilst delivering nutritional requirements presented as key considerations for future product development and research. This research highlights the importance of understanding the distinct values, attitudes and behaviours of different flexitarian groups as opposed to generalised research aimed at flexitarians per se.
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    Effects of intrinsic and extrinsic product characteristics related to protein source, health and environmental sustainability, on product choice and sensory evaluation of meatballs and plant-based alternatives
    (Elsevier Ltd, 2024-04) Giezenaar C; Godfrey AJR; Foster M; Hort J
    Health is cited as a major driver for substituting meat with plant-based meat alternatives (PBMAs). In contrast, many consumers are reportedly unaware of the difference in environmental impact between meat and PBMAs. This study determined relative effects of internal (protein source) and external (health/origin/sustainability) product attributes on product choice and (expected) liking of meat and PBMAs. Participants (n = 144) ranked ten sets of three product concepts from best to worst in a discrete choice experiment (DCE). Random combinations of four product attributes were presented on hypothetical product packages: i) protein source (beef/chickpea/soy protein); ii) health-star rating (1.5/4.5 stars); iii) ingredient origin (local/imported); iv) sustainability rating (green tick absent/present), and product worth, related to each of the 24 possible attribute combinations, was determined. Secondly, commercially-available beef, soy, and chickpea products were sensorially evaluated for expected/actual liking, both blindly and alongside combinations of internal/external product attributes used in the DCE. The DCE indicated all product attributes affected product worth. However, two consumer segments were established: i) a ‘Protein Cluster’ (47%) comprising consumers who chose ‘beef’ products regardless of the remaining attributes present, and ii) a ‘Health/Sustainability Cluster’ (53%) of consumers whose choices were driven by positive health/sustainability claims. Protein source drove both expected and actual liking of the samples (p < 0.001). Health/origin/sustainability also contributed to expected liking (p < 0.05), but only health consistently affected actual liking ratings (p < 0.05). In conclusion, half of consumers chose products based on health/origin/sustainability claims, whereas the other half selected products based on protein source. Origin/sustainability claims affected product choice, but minimally affected product experience of plant-based samples.
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    Profiling the novel plant-based meat alternative category: Consumer affective and sensory response in the context of perceived similarity to meat
    (Elsevier Ltd, 2024-07) Giezenaar C; Orr R; Godfrey AJR; Maggs R; Meika F; Hort J
    Plant-based meat alternatives (PBMAs) are increasingly popular and may contribute towards reduction of negative environmental impacts associated with the meat industry. Inferior sensory characteristics of PBMAs, compared to conventional meat products, remain a barrier for uptake of these products. This study aimed to profile a wide range of PBMAs for perceived similarity to meat, consumer liking, emotional response and sensory experience, and to determine consumer drivers of liking for this product category. Twenty-one PBMAs, spanning a broad range of product types (burger patties, sausages, meatball alternatives, chicken/beef pieces, bacon alternative, turkey roast alternative) and main protein ingredients (extruded plant proteins, tofu, or legumes/vegetables) representative of PBMAs available to Aotearoa New Zealand consumers, were tasted and evaluated by 140 Aotearoa New Zealand residents. Samples ranged widely in their perceived similarity to meat (median value range: 1.0–4.0 on a 5-point-scale) and overall liking ratings (mean ± SD, range: 35.1 ± 1.2––77.7 ± 17.4 on a 100-point hedonic scale). Overall liking ratings were driven mostly by liking for flavour, followed by texture, and less so by appearance. Sensorially, sample differentiation was mostly associated with variation in meat-related flavours and textures, or vegetable-related attributes. Notably meat flavour was the main driver of liking, and a very strong relationship (r = 0.92) was observed between perceived similarity to meat and overall sample liking ratings. Meat-like samples were also associated with positive emotional terms, whereas samples made from wholefoods were associated with negative emotional terms. Textural terms (‘gluey/slimy’, ‘pasty/doughy’) associated with wholefood products were also negative drivers for liking, and should be avoided in future PBMA products. In conclusion, the general population maintains a strong preference for PBMAs that are similar to meat, validating ongoing efforts to improve the meat-like properties of new and emerging products. PBMAs made from wholefoods require extensive product development to achieve consumer satisfaction across the category.
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    Metabolite profiling of peripheral blood plasma in pigs in early postnatal life fed whole bovine, caprine or ovine milk
    (Frontiers Media S.A., 2023-09-26) Jena A; Montoya CA; Fraser K; Giezenaar C; Young W; Mullaney JA; Dilger RN; Roy D; McNabb WC; Roy NC; Leroux C
    Ruminants' milk is commonly used for supplying nutrients to infants when breast milk is unavailable or limited. Previous studies have highlighted the differences between ruminants' milk composition, digestion, absorption, and fermentation. However, whether consuming different ruminants' milk impact the appearance of the circulatory blood metabolites in the early postnatal life is not well understood. The analysis conducted here aimed to determine the effect of feeding exclusively whole milk from bovine, caprine or ovine species to pigs, approximately 7 days-old for 15 days, on circulatory blood plasma metabolites. Relative intensities of plasma metabolites were detected using a liquid chromatography-mass spectrometry based metabolomic approach. Seven polar and 83 non-polar (lipids) metabolites in plasma were significantly different (false discovery rate < 0.05) between milk treatments. These included polar metabolites involved in amino acid metabolism and lipids belonging to phosphatidylcholine, lysophosphatidylcholine, sphingomyelin, and triglycerides. Compared to the caprine or bovine milk group, the relative intensities of polar metabolites and unsaturated triglycerides were higher in the peripheral circulation of the ovine milk group. In contrast, relative intensities of saturated triglycerides and phosphatidylcholine were higher in the bovine milk group compared to the ovine or caprine milk group. In addition, correlations were identified between amino acid and lipid intake and their appearance in peripheral blood circulation. The results highlighted that consuming different ruminants' milk influences the plasma appearance of metabolites, especially lipids, that may contribute to early postnatal life development in pigs.
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    Effects of Green and Gold Kiwifruit Varieties on Antioxidant Neuroprotective Potential in Pigs as a Model for Human Adults.
    (MDPI (Basel, Switzerland), 2024-04-09) Kanon AP; Giezenaar C; Roy NC; Jayawardana IA; Lomiwes D; Montoya CA; McNabb WC; Henare SJ; Digiacomo M
    Kiwifruit (KF) has shown neuroprotective potential in cell-based and rodent models by augmenting the capacity of endogenous antioxidant systems. This study aimed to determine whether KF consumption modulates the antioxidant capacity of plasma and brain tissue in growing pigs. Eighteen male pigs were divided equally into three groups: (1) bread, (2) bread + Actinidia deliciosa cv. 'Hayward' (green-fleshed), and (3) bread + A. chinensis cv. 'Hort16A' (yellow-fleshed). Following consumption of the diets for eight days, plasma and brain tissue (brain stem, corpus striatum, hippocampus, and prefrontal cortex) were collected and measured for biomarkers of antioxidant capacity, enzyme activity, and protein expression assessments. Green KF significantly increased ferric-reducing antioxidant potential (FRAP) in plasma and all brain regions compared with the bread-only diet. Gold KF increased plasma ascorbate concentration and trended towards reducing acetylcholinesterase activity in the brain compared with the bread-only diet. Pearson correlation analysis revealed a significant positive correlation between FRAP in the brain stem, prefrontal cortex, and hippocampus with the total polyphenol concentration of dietary interventions. These findings provide exploratory evidence for the benefits of KF constituents in augmenting the brain's antioxidant capacity that may support neurological homeostasis during oxidative stress.
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    Acute effects of fresh versus dried Hayward green kiwifruit on sleep quality, mood, and sleep-related urinary metabolites in healthy young men with good and poor sleep quality
    (Frontiers Media S.A., 2023-03-14) Kanon AP; Giezenaar C; Roy NC; McNabb WC; Henare SJ; Scholey A
    Background and aims: Daily kiwifruit (KF) consumption has been associated with improved sleep quality, but underlying physiological mechanisms are unknown. This study examined acute effects of fresh and dried green KF, compared with a water control, on sleep quality, mood, and urinary serotonin and melatonin metabolite concentrations. Methods: 24 men (age: 29 ± 1 years, body mass index: 24 ± 1 kg/m2) with poor (n = 12) or good (n = 12) sleep quality participated in a randomized, single-blind crossover study. One of three treatments was consumed with a standardized evening meal; (1) the flesh of two fresh green KF, (2) dried green KF powder (including skin; equivalent to dry matter of two fresh KF) mixed with water, or (3) a water control, in their own home. Subjective and objective sleep quality, mood, waking urinary 5-hydroxyindoleacetic acid (5-HIAA), 6-sulfatoxymelatonin (aMT6s), vitamin C and B-vitamin concentrations were determined. Results: Regardless of sleep quality group, compared to control, morning sleepiness, alertness upon awakening, and vigor were improved (p < 0.05) after dried KF consumption. Compared to control, both fresh and dried KF treatments tended (p < 0.1) toward improved esteem and total mood disturbance. Both KF treatments increased (fresh +1.56 ± 0.4 ng/g, p = 0.001; dried: +1.30 ± 0.4 ng/g, p = 0.004) urinary concentration of the serotonin metabolite 5-HIAA compared to the control (4.32 ± 0.4 ng/g). In poor sleepers, ease of awakening improved by 24% after dried KF consumption (p = 0.005) and tended to improve by 13% after fresh KF intake (p = 0.052) compared to the control. Good sleepers tended toward 9% improved ratings of getting to sleep with fresh KF (p = 0.053) compared to the control. Poor sleepers had lower amounts of some B-vitamins compared to good sleepers (p < 0.05). Conclusion: Consumption of dried or fresh KF with a standard evening meal, was associated with improved aspects of sleep quality and mood, possibly mediated through changes in serotonin metabolism. Clinical trial registration: [www.anzctr.org.au], identifier [ACTRN12621000046808].
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    The effects of ruminant milk treatments on hippocampal, striatal, and prefrontal cortex gene expression in pigs as a model for the human infant
    (Frontiers Media S.A., 2022-08-15) Jena A; Montoya CA; Young W; Mullaney JA; Roy D; Dilger RN; Giezenaar C; McNabb WC; Roy NC; Lim CK
    While infant formula is usually bovine milk-based, interest in other ruminant milk-based formulas is growing. However, whether different ruminant milk treatments with varying nutrient compositions influence the infant's brain development remains unknown. The aim was to determine the effects of consuming bovine, caprine, or ovine milk on brain gene expression in the early postnatal period using a pig model of the human infant. Starting at postnatal day 7 or 8, pigs were exclusively fed bovine, ovine, or caprine milk for 15 days. The mRNA abundance of 77 genes in the prefrontal cortex, hippocampus, and striatum regions was measured at postnatal day 21 or 22 using NanoString. The expression level of two hippocampal and nine striatal genes was most affected by milk treatments, particularly ovine milk. These modulatory genes are involved in glutamate, gamma-aminobutyric acid, serotonin, adrenaline and neurotrophin signaling and the synaptic vesicle cycle. The expression level of genes involved in gamma-aminobutyric acid signaling was associated with pigs' lactose intake. In contrast, milk treatments did not affect the mRNA abundance of the genes in the prefrontal cortex. This study provides the first evidence of the association of different ruminant milk treatments with brain gene expression related to cognitive function in the first 3 months of postnatal life.