Papers by Duncan Hedderley
Nutrition Research, 2015
This study examined the effect of a Boysenberry beverage (750 mg polyphenols), an apple fiber bev... more This study examined the effect of a Boysenberry beverage (750 mg polyphenols), an apple fiber beverage (7.5 g dietary fiber), and a Boysenberry plus apple fiber beverage (750 mg polyphenols plus 7.5 g dietary fiber) on gut health. Twenty-five individuals completed the study. The study was a placebo-controlled crossover study, where every individual consumed 1 of the 4 treatments in turn. Each treatment phase was 4-week long and was followed by a 2-week washout period. The trial beverages were 350 g taken in 2 doses every day (ie, 175 mL taken twice daily). The hypothesis for the study was that the combination of polyphenols and fiber would have a greater benefit on gut health than the placebo product or the fiber or polyphenols on their own. There were no differences in fecal levels of total bacteria, Bacteroides-Prevotella-Porphyromonas group, Bifidobacteriumspecies, Clostridium perfringens, or Lactobacillus species among any of the treatment groups. Fecal short chain fatty acid concentrations did not vary among treatment groups, although prostaglandin E2 concentrations were higher after consumption of the Boysenberry juice beverage. No significant differences were found in quantitative measures of gut health between the Boysenberry juice beverage, the apple fiber beverage, the Boysenberry juice plus apple fiber beverage, and the placebo beverage.
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Journal of Functional Foods, 2012
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Journal of Functional Foods, 2015
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Journal of Texture Studies, 2012
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Journal of Texture Studies, 2013
ABSTRACT Saliva addition plays an important role in bolus formation. During chewing, food breaks ... more ABSTRACT Saliva addition plays an important role in bolus formation. During chewing, food breaks down, exposing food particles to saliva. The aim of this study was to explore and understand how bolus moisture content changes during the oral processing of solid foods. Twelve subjects chewed commercially produced solid foods; the boluses were collected at different stages of the mastication process, including the swallowing point, and all of the boluses produced were analyzed for their moisture content. The chewing sessions were recorded on video, enabling the number of chews to be assessed for each subject and food type. Results showed that moisture content of boluses during mastication increased linearly at a rate depending on the subject and food types studied. It was found that for the food types studied, an increase in initial food moisture content increased the bolus moisture content at the swallowing point. Practical ApplicationsSensory perception experienced during oral processing of foods is through sensing the bolus properties, which change continuously in between ingestion and swallowing. Understanding changes in bolus moisture content, the role of food structure and effects on sensory perception can help in designing foods with predictable sensory attributes. This study demonstrated that while saliva additions vary between people and food types, they increase linearly during mastication. Changes in bolus moisture content during mastication could be used to guide the design of solid foods with target properties.
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Biological Invasions, 2000
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New Zealand Journal of Botany, 2005
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New Zealand Journal of Crop and Horticultural Science, 2016
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Journal of Agricultural and Food Chemistry, 2007
On the basis of structural and/or aroma analogies to known thrips (Thysanoptera: Thripidae) lures... more On the basis of structural and/or aroma analogies to known thrips (Thysanoptera: Thripidae) lures, 35 compounds (18 pyridine derivatives, 13 benzene derivatives, and 4 other compounds), consisting of both synthetic and naturally occurring compounds, were screened for their ability to bring about increased thrips capture in field experiments using water traps in Canterbury, New Zealand. Most of the thrips caught were New Zealand flower thrips (NZFT) (Thrips obscuratus) or onion thrips (OT) (Thrips tabaci). The greatest increase in capture for NZFT (158 times for female symbol cf. to water control) was for the known lure ethyl nicotinate, a 3-pyridyl ester. Ethyl isonicotinate, the 4-pyridyl regioisomer of ethyl nicotinate, not previously reported as a thrips lure, provided the greatest increases in capture for OT (31 times) of any of the compounds tested, significantly more than ethyl nicotinate. Other 4-pyridyl carbonyl compounds, including ethyl 4-pyridyl ketone, also increased OT capture significantly. The natural floral compound cis-jasmone, which increased trap capture of NZFT (female symbol 42 times, male symbol 25 times) but not OT, is reported as a thrips lure for the first time.
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Nutrients, 2016
Low dietary fibre intake has been associated with poorer health outcomes, therefore having the ab... more Low dietary fibre intake has been associated with poorer health outcomes, therefore having the ability to be able to quickly assess an individual's dietary fibre intake would prove useful in clinical practice and for research purposes. Current dietary assessment methods such as food records and food frequency questionnaires are time-consuming and burdensome, and there are presently no published short dietary fibre intake questionnaires that can quantify an individual's total habitual dietary fibre intake and classify individuals as low, moderate or high habitual dietary fibre consumers. Therefore, we aimed to develop and validate a habitual dietary fibre intake short food frequency questionnaire (DFI-FFQ) which can quickly and accurately classify individuals based on their habitual dietary fibre intake. In this study the DFI-FFQ was validated against the Monash University comprehensive nutrition assessment questionnaire (CNAQ). Fifty-two healthy, normal weight male (n = 17) and female (n = 35) participants, aged between 21 and 61 years, completed the DFI-FFQ twice and the CNAQ once. All eligible participants completed the study, however the data from 46% of the participants were excluded from analysis secondary to misreporting. The DFI-FFQ cannot accurately quantify total habitual dietary fibre intakes, however, it is a quick, valid and reproducible tool in classifying individuals based on their habitual dietary fibre intakes.
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Asia Pacific Journal of Clinical Nutrition, Feb 1, 2006
The use of dietary supplements has increased over the past 10 years, with up to 50% of adults bei... more The use of dietary supplements has increased over the past 10 years, with up to 50% of adults being reported to have taken dietary supplements. The types of supplements taken are often related to physical morbidities. However, information about their use in combination with prescription drugs is lacking. In particular, there is little information on the use of supplements by people with depression. Our aim was to examine the use of dietary supplements by people being treated for depression. Seventy-two participants who were being treated for depression in the community were recruited for a clinical trial to determine the effect of fish oil on mood in the treatment of depression. The results of the primary analysis are reported elsewhere. Exclusion criteria included any co-existing psychiatric disorder (except anxiety disorders), blood clotting disorders, unstable medical conditions, and those taking fish oil supplements. Demographic information, details about the participants' depression and current therapies, use of dietary and herbal supplements in the previous 12 months, and physical activity data were collected at baseline. Characteristics of supplement users were compared with those of non-users using either chi-square or Mann-Whitney U tests. Forty-five (63%) of 72 participants who provided dietary supplement information had taken at least one dietary supplement within the previous 12 months. On average, supplement users were found to have taken 2.8 (SD=1.56) dietary supplements during the assessment period. Women were more likely to be taking supplements than men (P<0.001). In conclusion, the use of dietary supplements is common among people being treated for depression. This has important implications for clinical practice as little is known about supplement-drug interactions.
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New Biotechnology, 2016
Experimental methods are constantly being improved by new technology. Recently a new technology, ... more Experimental methods are constantly being improved by new technology. Recently a new technology, NanoString(®), has been introduced to the market for the analysis of gene expression. Our experiments used adipose and liver samples collected from a rat feeding trial to explore gene expression changes resulting from a diet of 7.5% seaweed. Both quantitative real-time polymerase chain reaction (qPCR) and NanoString methods were employed to look at expression of genes related to fat and glucose metabolism and this paper compares results from both methods. We conclude that NanoString offers a valuable alternative to qPCR and our data suggest that results are more accurate because of the reduced sample handling and direct quantification of gene copy number without the need for enzymatic amplification. However, we have highlighted a potential challenge for both methods, which needs to be addressed when designing primers or probes. We suggest a literature search for known splice variants of a particular gene to be completed so that primers or probes can be designed that do not span exons which may be affected by alternative gene sequences.
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This report outlines the findings from a three year research programme, funded by the Foundation ... more This report outlines the findings from a three year research programme, funded by the Foundation for Research, Science and Technology, investigating the New Zealand public&amp;#x27;s perceptions of transgenic plant products. The research was carried out by HortResearch, ...
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Australasian Journal of Information Systems, 2005
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Genes & nutrition, 2007
Multidrug resistance targeted mutation (mdr1a (-/-) ) mice spontaneously develop intestinal infla... more Multidrug resistance targeted mutation (mdr1a (-/-) ) mice spontaneously develop intestinal inflammation. The aim of this study was to further characterize the intestinal inflammation in mdr1a (-/-) mice. Intestinal samples were collected to measure inflammation and gene expression changes over time. The first signs of inflammation occurred around 16 weeks of age and most mdr1a (-/-) mice developed inflammation between 16 and 27 weeks of age. The total histological injury score was the highest in the colon. The inflammatory lesions were transmural and discontinuous, revealing similarities to human inflammatory bowel diseases (IBD). Genes involved in inflammatory response pathways were up-regulated whereas genes involved in biotransformation and transport were down-regulated in colonic epithelial cell scrapings of inflamed mdra1 (-/-) mice at 25 weeks of age compared to non-inflamed FVB mice. These results show overlap to human IBD and strengthen the use of this in vivo model to stud...
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Asia Pacific journal of clinical nutrition, 2006
The use of dietary supplements has increased over the past 10 years, with up to 50% of adults bei... more The use of dietary supplements has increased over the past 10 years, with up to 50% of adults being reported to have taken dietary supplements. The types of supplements taken are often related to physical morbidities. However, information about their use in combination with prescription drugs is lacking. In particular, there is little information on the use of supplements by people with depression. Our aim was to examine the use of dietary supplements by people being treated for depression. Seventy-two participants who were being treated for depression in the community were recruited for a clinical trial to determine the effect of fish oil on mood in the treatment of depression. The results of the primary analysis are reported elsewhere. Exclusion criteria included any co-existing psychiatric disorder (except anxiety disorders), blood clotting disorders, unstable medical conditions, and those taking fish oil supplements. Demographic information, details about the participants' d...
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Journal of Functional Foods, 2015
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Molecular Nutrition & Food Research, 2014
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Plant Foods for Human Nutrition, 2012
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Papers by Duncan Hedderley