22,321 results for Journal article

  • The moss Bryum argenteum var. muticum Brid. is well adapted to cope with high light in continental Antarctica

    Schroeter, Burkhard; Green, T.G. Allan; Kulle, Daniel; Pannewitz, Stefan; Schlensog, Mark; Sancho, Leopoldo G. (2012)

    Journal article
    University of Waikato

    The net photosynthetic rate (NP), chlorophyll fluorescence, carotenoid content and chlorophyll content of the cosmopolitan moss Bryum argenteum were measured in the field at Botany Bay, southern Victoria Land, continental Antarctica (77°S). Comparisons were made between sun- and shade-adapted forms, and changes were followed as the moss emerged from under the snow and during exposure of shade and sun forms to ambient light. Shade forms had lower light compensation and saturation values for NP but little difference in maximal NP rates. Shade forms exposed to ambient light changed rapidly (within five days) towards the performance of the sun forms. Surprisingly, this change was not by acclimation of shoots but by the production of new shoots. Chlorophyll and carotenoid levels measured on a molar chlorophyll basis showed no difference between sun and shade forms and also little change during emergence. The constant molar relationship between carotenoids and chlorophyll plus the high levels of the xanthophyll cycle pigments suggest that protection of the chlorophyll antenna was constitutive. This is an adaptation to the very high light levels that occur when the plants are active in continental Antarctica and contrasts to the situation in more temperate areas where high light is normally avoided by desiccation.

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  • Is kanuka and manuka establishment in grassland constrained by mycorrhizal abundance?

    Davis, M.; Dickie, I. A.; Paul, T.; Carswell, F.

    Journal article
    Lincoln University

    Two indigenous small tree and shrub species, kanuka (Kunzea ericoides) and manuka (Leptospermum scoparium), have potential as reforestation species in New Zealand as they are forest pioneer species that can invade grassland naturally from present seed sources. The aim of this study was to determine if establishment of kanuka and manuka from seed in grassland distant from stands of these species might be constrained by lack of appropriate mycorrhizal fungi. Both species were grown in an unsterilised grassland soil from a low productivity montane site assumed to be devoid of appropriate mycorrhizal fungi and inoculated with sterilised or unsterilised O-horizon or mineral soil from beneath three kanuka and three manuka communities expected to contain such fungi. Inoculation with unsterilised O-horizon soil improved kanuka biomass by 36-92%, depending on the source of the inoculant. Inoculation did not improve manuka biomass. No ectomycorrhizal infection was observed on either kanuka or manuka in samples examined under binocular microscope. The biomass response by kanuka to inoculation may be due to introduction of more effective arbuscular mycorrhizal fungi from kanuka communities or possibly to the introduction of soil microorganisms. Testing of inoculation under field conditions will be essential to determine whether establishment of either species in grassland soil by seeding is seriously constrained by lack of appropriate mycorrhizal fungi or soil microorganisms.

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  • A delicate balancing act

    Foote, Hamish; Griffiths, Pete (2017-05-10T05:39:22Z)

    Journal article
    Unitec

    This paper examines a bicultural approach to the development of planting strategies for landscapes and asks the question: In what ways can vegetation help to create a bicultural landscape? The case studies discussed include planting and design directives that are divergent in nature, however perhaps they can also help to demonstrate togetherness.

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  • Nasty Feminism, Nasty Feminists

    Thomas, Nicol

    Journal article
    University of Canterbury Library

    The question “what does a woman want?” has been asked by psychoanalysts in the past—particularly by Freud and Lacan—and is a question that has been taken up by feminist scholarship and epistemology. This essay addresses this complex question via both feminist research and enquiry and a Lacanian psychoanalytic praxis. The issue of women’s very speech is crucial, which is a cornerstone element of the feminisms of Spender, Steinem, Hanisch, Irigaray, Cixous, Felski, Jane and Ford. Lacan makes the point that feminine jouissance stands outside the phallic order and thus must be incorporated in the psychoanalytic consideration of what is the sexed position, woman. This essay argues that Lacan’s psychoanalytic considerations have great political and practical import for contemporary feminist practices and epistemology, via the positioning of women’s very speech outside of—but apposite to—a provably violent misogynistic patriarchy.

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  • Book Review - Capitalism and Desire: The Psychic Cost of Free Markets by Todd McGowan

    Zupancic, Alenka

    Journal article
    University of Canterbury Library

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  • Minimally invasive, patient specific, beat-by-beat estimation of left ventricular time varying elastance

    Davidson S; Pretty C; Pironet A; Kamoi S; Balmer J; Desaive T; Chase JG (2017)

    Journal article
    University of Canterbury Library

    Background: The aim of this paper was to establish a minimally invasive method for deriving the left ventricular time varying elastance (TVE) curve beat-by-beat, the monitoring of which's inter-beat evolution could add significant new data and insight to improve diagnosis and treatment. The method developed uses the clinically available inputs of aortic pressure, heart rate and baseline end-systolic volume (via echocardiography) to determine the outputs of left ventricular pressure, volume and dead space volume, and thus the TVE curve. This approach avoids directly assuming the shape of the TVE curve, allowing more effective capture of intra- and inter-patient variability. Results: The resulting TVE curve was experimentally validated against the TVE curve as derived from experimentally measured left ventricular pressure and volume in animal models, a data set encompassing 46,318 heartbeats across 5 Piétrain pigs. This simulated TVE curve was able to effectively approximate the measured TVE curve, with an overall median absolute error of 11.4% and overall median signed error of -2.5%. Conclusions: The use of clinically available inputs means there is potential for real-time implementation of the method at the patient bedside. Thus the method could be used to provide additional, patient specific information on intra- and inter-beat variation in heart function.

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  • Notes on Contributors

    Zeiher, Cindy; Grimshaw, Mike

    Journal article
    University of Canterbury Library

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  • Preference of a native beetle for “exoticism,” characteristics that contribute to invasive success of Costelytra zealandica (Scarabaeidae: Melolonthinae)

    Lefort, M. C.; Boyer, Stephane; Vereijssen, Jessica; Sprague, R.; Glare, Travis; Worner, Susan P.

    Journal article
    Lincoln University

    Widespread replacement of native ecosystems by productive land sometimes results in the outbreak of a native species. In New Zealand, the introduction of exotic pastoral plants has resulted in diet alteration of the native coleopteran species, Costelytra zealandica (White) (Scarabaeidae) such that this insect has reached the status of pest. In contrast, C. brunneum (Broun), a congeneric species, has not developed such a relationship with these ‘novel’ host plants. This study investigated the feeding preferences and fitness performance of these two closely related scarab beetles to increase fundamental knowledge about the mechanisms responsible for the development of invasive characteristics in native insects. To this end, the feeding preference of third instar larvae of both Costelytra species was investigated using an olfactometer device, and the survival and larval growth of the invasive species C. zealandica were compared on native and exotic host plants. Costelytra zealandica, when sampled from exotic pastures, was unable to fully utilise its ancestral native host and showed higher feeding preference and performance on exotic plants. In contrast, C. zealandica sampled from native grasslands did not perform significantly better on either host and showed similar feeding preferences to C. brunneum, which exhibited no feeding preference. This study suggests the possibility of strong intraspecific variation in the ability of C. zealandica to exploit native or exotic plants, supporting the hypothesis that such ability underpins the existence of distinct host-races in this species.

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  • An explanation of yield differences in three potato cultivars

    Oliveira, J.; Brown, H.; Gash, Alan; Moot, Derrick J.

    Journal article
    Lincoln University

    Under ideal growing conditions, yield is the product of intercepted photosynthetically active radiation (PARi) and its conversion efficiency to dry matter (radiation use efficiency, RUE). For potato (Solanum tuberosum L.) the ability of the leaf to convert the PARi into carbohydrates (source) and the storage capacity of the tubers (sink) affect the potential growth of individual tubers and therefore crop yield. This study describes these mechanisms for three commercial potato cultivars (Bondi, Fraser, and Russet Burbank) grown in non-limiting field conditions. At final harvest Bondi had the largest tuber yield and produced heavier but fewer tubers compared with Fraser and Russet Burbank. All crops had similar total accumulated radiation interception (Rcum), and yield differences were explained by the RUE which was highest for Bondi, lowest for Fraser, with Russet Burbank intermediate. Fraser had the lowest rate of canopy senescence, maintained the lowest specific leaf area (SLA) for most of the period of tuber bulking and maintained the highest dry matter (DM) allocated to leaves at the end of the tuber filling phase. Throughout the crop growing period Bondi had a larger tuber sink compared with Fraser and Russet Burbank. These results suggest that potato tuber production was limited by the “sink strength” and RUE in the lower yield varieties. The larger sink in Bondi, caused by shorter stolons, enabled higher rates of tuber filling which produced the largest tubers in the middle node positions and the highest average tuber weight per plant among these cultivars.

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  • Nitrous oxide fluxes, soil oxygen, and denitrification potential of urine- and non-urine-treated soil under different irrigation frequencies

    Owens, J.; Clough, Timothy J.; Laubach, J.; Hunt, J. E.; Venterea, R. T.; Phillips, R. L.

    Journal article
    Lincoln University

    © American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. 5585 Guilford Rd., Madison, WI 53711 USA. All rights reserved. Despite increased use of irrigation to improve forage quality and quantity for grazing cattle (Bos taurus, Linnaeus), there is a lack of data that assess how irrigation practices influence nitrous oxide (N2O) emissions from urine-affected soils. Irrigation effects on soil oxygen (O2) availability, a primary controller of N2O fluxes, is poorly understood. It was hypothesized that increased irrigation frequency would result in lower N2O emissions by increasing soil moisture and decreasing soil O2 concentrations. This would favor more N2O reduction to dinitrogen (N2). We examined effects of high (3-d) versus low (6-d) irrigation frequency with and without bovine urine addition to pasture. Nitrous oxide fluxes were measured daily for 35 d. Soil O2, temperature, and water content were continuously measured at multiple depths. Inorganic nitrogen, organic carbon, and soil pH were measured at 6-d intervals. Measurements of denitrification enzyme activity with and without acetylene inhibition were used to infer the N2O/(N2O + N2) ratio. The N2O/(N2O + N2) ratio was lower under high- compared with low-frequency irrigation, suggesting greater potential for N2O reduction to N2 with more frequent irrigation. Although N2O fluxes were increased by urine addition, they were not affected by irrigation frequency. Soil O2 decreased temporarily after urine deposition, but O2 dynamics did not explain N2O dynamics. Relative soil gas diffusivity (DP/DO) was a better predictor of N2O fluxes than O2 concentration. On a freedraining soil, increasing irrigation frequency while providing the same total water volume did not enhance N2O emissions under ruminant urine patches in a grazed pasture.

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  • Engaging Māori in Biobanking and Genetic Research: Legal, Ethical and Policy Challenges

    Beaton, Angela; Smith, Barry; Toki, Valmaine; Southey, Kim; Hudson, Maui (2015)

    Journal article
    University of Waikato

    Publically funded biobanking initiatives and genetic research should contribute towards reducing inequalities in health by reducing the prevalence and burden of disease. It is essential that Maori and other Indigenous populations share in health gains derived from these activities. The Health Research Council of New Zealand has funded a research project (2012-2015) to identify Maori perspectives on biobanking and genetic research, and to develop cultural guidelines for ethical biobanking and genetic research involving biospecimens. This review describes relevant values and ethics embedded in Maori indigenous knowledge, and how they may be applied to culturally safe interactions between biobanks, researchers, individual participants, and communities. Key issues of ownership, privacy, and consent are also considered within the legal and policy context that guides biobanking and genetic research practices within New Zealand. Areas of concern are highlighted and recommendations of international relevance are provided. To develop a productive environment for "next-generation" biobanking and genomic research,"‘next-generation" regulatory solutions will be required.

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  • Calcium and oxalate contents of curly leaf (Petroselinum crispum) and flat leaf (P. crispum var. neapolitanum) parsley cultivars

    Savage, Geoffrey P.; Vanhanen, Leo P.

    Journal article
    Lincoln University

    The total, soluble and insoluble oxalate contents of the leaves and stems of curly leaf (Petroselinum crispum) and flat leaf (P. crispum var. neapolitanum) parsley cultivarswere extracted from fresh tissue and measured using HPLC chromatography. There were no significant differences between the total and insoluble oxalate contents of the leaves between the flat leaf and curly leaf cultivars. There was a small difference (P < 0.05) between the soluble oxalate contents of the leaves of the two cultivars. The mean total, soluble and insoluble oxalates of the leaves of the two cultivars were 1137.0, 177.9 and 959.3 mg/100 g dry matter (DM), respectively. The mean total, soluble and insoluble oxalate contents of the stems were 1680.7, 386.2 and 1294.5 mg/100 g DM, respectively, and these were significantly higher than the mean values for the leaves of the two cultivars. Insoluble oxalate made up a mean of 77.0% of the curly leaf stems and leaves compared to a mean of 84.4% found in the flat-leaved cultivar. Unavailable calcium, that is, calcium bound to oxalate as insoluble oxalate, made up a mean of 26.9% of the total calcium in the leaves of both cultivars while the unavailable calcium made up 45.0% of the total calcium in the stems of the two cultivars. Overall, the oxalate contents of both parsley cultivars are relatively high, on a dry matter basis, but their overall contribution to dietary intake is likely to be quite small as parsley is an herb that is only used in small amounts to garnish foods.

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  • Effect of temperature on the drying characteristics, colour and ascorbic acid content of green and gold kiwifruits

    Diamante, Lemuel; Durand, M.; Savage, Geoffrey P.; Vanhanen, Leo P.

    Journal article
    Lincoln University

    The drying characteristics of green and gold kiwifruit were determined using an air velocity of 0.20 m/s at ambient humidity and different temperatures (60, 80 and 100°C). The colour values (L*, a* and b*) and ascorbic acid content were also measured for the different fresh and dried kiwifruits. The drying of green and gold kiwifruit slices consists of a constant rate period (CRP) and two parts of falling rate period (FRP). The CRP drying rate, first and second FRP drying coefficients increase with drying temperature for both the green and gold kiwifruit slices. The first critical moisture content (CMC) and the dynamic equilibrium MC decrease with drying temperature for both the green and gold kiwifruit slices. The second CMC for both green and gold kiwifruit slices were not affected by drying temperature. The values for chroma of the dried green kiwifruit increased while the dried gold kiwifruit decreased with higher temperature as compared with the fresh samples. The values for hue angle of dried green and gold kiwifruits decreased at higher temperature. Lastly, the values for browning index of dried green and gold kiwifruits increased at higher temperature. There was not much change on the ascorbic acid contents of fresh and dried green and gold kiwifruits when drying at 60 and 80°C. But there was about 19% decrease in the ascorbic acid content of dried green and gold kiwifruits after drying at 100°C.

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  • Vacuum fried gold Kiwifruit: Effects of frying process and pre-treatment on the physico-chemical and nutritional qualities

    Diamante, Lemuel; Presswood, Hannah; Savage, Geoffrey P.; Vanhanen, Leo P.

    Journal article
    Lincoln University

    A study was conducted to determine the effects of frying process and pre-treatment on the physico-chemical and nutritional qualities of vacuum fried gold kiwifruit. The kiwifruit samples were peeled and cut into slices 5 mm thick. Half of the kiwifruit samples were soaked for one hour in a 33% maltodextrin solution, then placed into plastic bags and frozen and the other half (unsoaked) were simply frozen. The two set of samples were subjected to three frying processes and all at 2.3 kPa vacuum, after which the kiwifruit was removed from the fryer and centrifuged in cheese cloth for four minutes to remove excess surface oil. Generally, the vacuum fried gold kiwifruit samples from the 80°C for 50 minutes process gave higher moisture content and lower oil content followed by the samples from the 90°C for 35 minutes process and then the 100°C for 25 minutes process. The vacuum fried samples from the 100°C for 25 minutes process gave consistently higher total colour change and browning index, followed by the 90°C for 35 minutes process and then the 80°C for 50 minutes process. The unsoaked sample from the 80°C for 50 minutes process gave significantly lower breaking force than the sample from the 100°C for 25 minutes process. There was no significant difference in the breaking force of all vacuum fried soaked samples. Generally the samples from the 80°C for 50 minutes process gave higher ascorbic acid contents followed by the samples from the 90°C for 35 minutes process and then the 100°C for 25 minutes process. © 2011.

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  • Addition of calcium compounds to reduce soluble oxalate in a high oxalate food system

    Bong, W.-C.; Vanhanen, Leo P.; Savage, Geoffrey P.

    Journal article
    Lincoln University

    Spinach (Spinacia oleracea L.) is often used as a base vegetable to make green juices that are promoted as healthy dietary alternatives. Spinach is known to contain significant amounts of oxalates, which are toxic and, if consumed regularly, can lead to the development of kidney stones. This research investigates adding 50 to 500 mg increments of calcium carbonate, calcium chloride, calcium citrate and calcium sulphate to 100 g of raw homogenates of spinach to determine whether calcium would combine with the soluble oxalate present in the spinach. Calcium chloride was the most effective additive while calcium carbonate was the least effective. The formation of insoluble oxalate after incubation at 25°C for 30 minutes is a simple practical step that can be incorporated into the juicing process. This would make the juice considerably safer to consume on a regular basis.

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  • Comparison of oxalate contents and recovery from two green juices prepared using a masticating juicer or a high speed blender

    Vanhanen, Leo P.; Savage, Geoffrey P.

    Journal article
    Lincoln University

    © 2015 The Authors. Background: Juicing is a popular health trend where green juice is prepared from a range of common vegetables. If spinach is included in the mix then the juice may contain significant quantities of oxalates and these are not safe to consume regularly in large amounts as they predispose some people to kidney stone formation. Methods: Green juice, prepared from spinach and other common vegetables using a high speed blender that produced a juice containing all the original fiber of the processed raw vegetables, was compared with a juice produced using a masticating juicer, where the pulp containing most of the fiber was discarded in the process. The oxalate contents of both juices were measured using HPLC chromatography. Results: Two juices were prepared using each processing method, one juice contained a high level of spinach, which resulted in a juice containing high levels of total, soluble and insoluble oxalates; the other was a juice mixture made from the same combination of vegetables but containing half the level of spinach, which resulted in a juice containing considerably (P < 0.001) lower levels of oxalates. Removal of the pulp fraction from the green vegetable juice had resulted in significantly (P < 0.01) higher levels of oxalates in the remaining juices made from both levels of spinach. Conclusion: Green juices prepared using common vegetables can contain high levels of soluble oxalates, which will vary with the type and proportion of vegetables used and whether or not the pulp fraction was retained during processing.

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  • Analysing the robustness of spice chains in Nepal from a smallholder perspective

    Bhattarai, Salil; Lyne, M. C.; Martin, Sandra K.

    Journal article
    Lincoln University

    This study assesses the performance of supply chains for ginger and large cardamom, two major export crops produced in Nepal. In particular, it aims to identify factors that constrain marketing choices available to smallholders, so limiting the chain`s robustness from their perspective. A qualitative case study method was used to gather and analyse data on farmer-buyer dyads in the ginger and cardamom chains. These case studies were informed by a conceptual model based on Transaction Cost Economics. The analysis included a cross-case comparison to identify the effects of external attributes on the modes of engagement available to smallholders. Informal market trading was the only mode of smallholder engagement observed in both chains. However, there was evidence that smallholders had previously engaged in relational contracts in the ginger chain, and in 'captive' relational contracts in the cardamom chain. The analysis suggests that access to other modes of engagement is constrained mainly by under-investment in value-adding assets. Traditional cooperatives can and do help to resolve problems of asymmetric information and high unit transaction costs, but more innovative cooperative models are required to encourage the investment needed to finance value-adding assets and activities.

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  • The Natural Compound Fucoidan From New Zealand Undaria Pinnatifida Synergizes With the ERBB Inhibitor Lapatinib Enhancing Melanoma Growth Inhibition

    Thakur, V; Lu, J; Roscilli, G; Aurisicchio, L; Cappelletti, M; Pavoni, E; White, WL; Bedogni, B

    Journal article
    Auckland University of Technology

    Melanoma remains one of the most aggressive and therapy-resistant cancers. Finding new treatments to improve patient outcomes is an ongoing effort. We previously demonstrated that melanoma relies on the activation of ERBB signaling, specifically of the ERBB3/ERBB2 cascade. Here we show that melanoma tumor growth is inhibited by 60% over controls when treated with lapatinib, a clinically approved inhibitor of ERBB2/EGFR. Importantly, tumor growth is further inhibited to 85% when the natural compound fucoidan from New Zealand U. pinnatifida is integrated into the treatment regimen. Fucoidan not only enhances tumor growth inhibition, it counteracts the morbidity associated with prolonged lapatinib treatment. Fucoidan doubles the cell killing capacity of lapatinib. These effects are associated with a further decrease in AKT and NFκB signaling, two key pathways involved in melanoma cell survival. Importantly, the enhancing cell killing effects of fucoidan can be recapitulated by inhibiting ERBB3 by either a specific shRNA or a novel, selective ERBB3 neutralizing antibody, reiterating the key roles played by this receptor in melanoma. We therefore propose the use of lapatinib or specific ERBB inhibitors, in combination with fucoidan as a new treatment of melanoma that potentiates the effects of the inhibitors while protecting from their potential side effects.

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  • Effect of Kimchi Fermentation on Oxalate Levels in Silver Beet (Beta vulgaris var. cicla)

    Wadamori, Y.; Vanhanen, Leo P.; Savage, Geoffrey P.

    Journal article
    Lincoln University

    Total, soluble and insoluble oxalates were extracted and analyzed by high performance liquid chromatography (HPLC) following the preparation of kimchi using silver beet (Beta vulgaris var. cicla) stems and leaves. As silver beet contains high oxalate concentrations and consumption of high levels can cause the development of kidney stones in some people, the reduction of oxalate during preparation and fermentation of kimchi was investigated. The silver beet stems and leaves were soaked in a 10% brine solution for 11 h and then washed in cold tap water. The total, soluble and insoluble oxalate contents of the silver beet leaves were reduced by soaking in brine, from 4275.81 ± 165.48 mg/100 g to 3709.49 ± 216.51 mg/100 g fresh weight (FW). Fermenting the kimchi for 5 days at 19.3 ± 0.8 °C in 5 L ceramic jars with a water airtight seal resulted in a mean 38.50% reduction in total oxalate content and a mean 22.86% reduction in soluble oxalates. The total calcium content was essentially the same before and after the fermentation of the kimchi (mean 296.1 mg/100 g FW). The study showed that fermentation of kimchi significantly (p < 0.05) reduced the total oxalate concentration in the initial mix from 609.32 ± 15.69 to 374.71 ± 7.94 mg/100 g FW in the final mix which led to a 72.3% reduction in the amount of calcium bound to insoluble oxalate.

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  • Mineral analysis of pine nuts (Pinus spp.) grown in New Zealand

    Vanhanen, Leo P.; Savage, Geoffrey P.

    Journal article
    Lincoln University

    Mineral analysis of seven Pinus species grown in different regions of New Zealand; Armand pine (Pinus armandii Franch), Swiss stone pine (Pinus cembra L.), Mexican pinyon (Pinus cembroides Zucc. var. bicolor Little), Coulter pine (Pinus coulteri D. Don), Johann’s pine (Pinus johannis M.F. Robert), Italian stone pine (Pinus pinea L.) and Torrey pine (Pinus torreyana Parry ex Carrière), was carried out using an inductively coupled plasma optical emission spectrophotometer (ICP-OES) analysis. Fourteen different minerals (Al, B, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S and Zn) were identified in all seven varieties, except that no Al or Na was found in Pinus coulteri D. Don. New Zealand grown pine nuts are a good source of Cu, Mg, Mn, P and Zn, meeting or exceeding the recommended RDI for these minerals (based on an intake of 50 g nuts/day) while they supplied between 39%–89% of the New Zealand RDI for Fe. Compared to other commonly eaten tree-nuts New Zealand grown pine nuts are an excellent source of essential minerals.

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