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    Investigating the health benefits of Monty’s Surprise apple phytochemicals : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Manawatū, New Zealand. EMBARGOED until 18 November 2027.
    (Massey University, 2024) Nezbedová, Linda
    Cancer is a major health concern worldwide, requiring effective prevention strategies to reduce its burden. There is evidence suggesting that diet plays an important role in disease prevention. Apples are an example of a commonly available fruit that can be easily incorporated into a diet to reduce the risk of chronic disease and some cancers. Apples are rich in phytochemicals with chemo-preventative properties. However, assessing their benefits in humans is complex due to various factors affecting phytochemical composition and low bioavailability. Understanding and controlling for these factors is crucial for maximising their potential in preventing cancer and promoting human health. The PhD project presented in this thesis uses a multidisciplinary ‘from orchard to fork to function’ approach to evaluate the health benefits of phytochemicals in a New Zealand heritage apple cultivar known as Monty’s Surprise, with an emphasis on cancer prevention. This thesis particularly focuses on apple’s most abundant phytochemical group known as phenolic compounds. After controlling fruit harvest and maturity, Monty’s Surprise apple was found to contain high concentrations of health beneficial phenolics, especially procyanidins, with apple skin having higher total phenolic content compared to its flesh. Pureeing was identified as a suitable processing technique with minimal impact on apple’s phenolics, allowing long-term preservation and creating uniform material for use in intervention and feeding trials. Moreover, Monty’s Surprise apple extract depleted of sugars inhibited the proliferation of lung, breast, and colorectal cancer cells in a dose-dependent manner in vitro. Lastly, in a human acute feeding trial, Monty’s Surprise apple puree increased plasma antioxidant capacity and decreased postprandial glucose response compared to sugar-matched placebo. The feeding trial also showed that procyanidins were not detected in the participant’s blood, while epicatechin and chlorogenic acid, which are prevalent phenolics in Monty’s Surprise apple puree, were absorbed into the bloodstream. Therefore, these compounds were available to contribute to the improved health parameters measured in the study. This study offers practical recommendations for optimising harvesting, storage, and processing practices to preserve and more clearly elucidate the health-promoting properties of phenolics in apples. Overall, this research demonstrated the potential health benefits of Monty’s Surprise apple and its phenolics, suggesting its value as a functional food for improving human health and well-being.
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    Value added wheat through applied genomic prediction : a genomic approach for breeding low gluten epitope wheat : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Plant Breeding and Genetics at Massey University, Palmerston North, New Zealand. EMBARGOED until 24 July 2026.
    (Massey University, 2023) Macalister, Jamie
    Gluten epitopes are known to trigger coeliac disease (CD) in affected consumers and are believed to be linked to some cases of gluten intolerance. Research suggests that if consumers were exposed to wheat with reduced concentrations of gluten epitopes, the incidence of CD and gluten intolerance may be reduced. Methods have recently been developed allowing researchers to measure gluten epitope concentrations in wheat. This offers wheat breeders the potential to select towards varieties with lower epitope concentrations than existing cultivars. However, the methods for measuring epitope concentrations remain costly and time consuming. Therefore, it is proposed that a genomic based approach for breeding low epitope wheat lines is a more practical method than traditional phenotype-based selections. The genetic factors associated with epitope concentrations remain poorly understood. In this thesis, heritability estimates of between 0.37-0.93 are reported for concentrations of 6 distinct gluten epitopes. The associations between epitope concentrations and baking quality are also assessed and are shown to range from being near zero for some epitopes to strong positive correlations between other epitopes and particular baking quality characteristics. A Genome Wide Association Study and a model for genomic prediction are employed to determine the genetic factors associated with epitope concentrations. In these analyses, 3 significant genomic windows are identified as being associated with concentrations of 3 particular epitopes. Empirical prediction accuracies of between 0.16-0.53 are observed for predictions of epitope concentrations in a breeding population. Additionally, accuracies of between 0.37-0.67 are achieved by adjusting the population structure to represent the ideal circumstances that breeders would aim to achieve in their training and target populations. These results demonstrate that genomic selection (GS) will be an effective method for breeding low gluten epitope wheat. The outcome of this thesis will allow implementation of GS in the New Zealand Institute for Plant & Food Research wheat breeding program where epitope concentrations will be established as a new breeding target. This is expected to lead to the release of niche, low epitope cultivars with a value-add component that benefits growers, industry and consumers.