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Item 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 JMAppropriate 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.Item Protein Intake at Twice the RDA in Older Men Increases Circulatory Concentrations of the Microbiome Metabolite Trimethylamine-N-Oxide (TMAO)(MDPI (Basel, Switzerland), 2019-09-12) Mitchell SM; Milan AM; Mitchell CJ; Gillies NA; D'Souza RF; Zeng N; Ramzan F; Sharma P; Knowles SO; Roy NC; Sjödin A; Wagner K-H; Zeisel SH; Cameron-Smith DHigher dietary protein intake is increasingly recommended for the elderly; however, high protein diets have also been linked to increased cardiovascular disease (CVD) risk. Trimethylamine-N-oxide (TMAO) is a bacterial metabolite derived from choline and carnitine abundant from animal protein-rich foods. TMAO may be a novel biomarker for heightened CVD risk. The purpose of this study was to assess the impact of a high protein diet on TMAO. Healthy men (74.2 ± 3.6 years, n = 29) were randomised to consume the recommended dietary allowance of protein (RDA: 0.8 g protein/kg bodyweight/day) or twice the RDA (2RDA) as part of a supplied diet for 10 weeks. Fasting blood samples were collected pre- and post-intervention for measurement of TMAO, blood lipids, glucose tolerance, insulin sensitivity, and inflammatory biomarkers. An oral glucose tolerance test was also performed. In comparison with RDA, the 2RDA diet increased circulatory TMAO (p = 0.002) but unexpectedly decreased renal excretion of TMAO (p = 0.003). LDL cholesterol was increased in 2RDA compared to RDA (p = 0.049), but no differences in other biomarkers of CVD risk and insulin sensitivity were evident between groups. In conclusion, circulatory TMAO is responsive to changes in dietary protein intake in older healthy males.Item Metabolome and microbiome profiling of a stress-sensitive rat model of gut-brain axis dysfunction(Springer Nature Limited, 2019-10-01) Bassett SA; Young W; Fraser K; Dalziel JE; Webster J; Ryan L; Fitzgerald P; Stanton C; Dinan TG; Cryan JF; Clarke G; Hyland N; Roy NCStress negatively impacts gut and brain health. Individual differences in response to stress have been linked to genetic and environmental factors and more recently, a role for the gut microbiota in the regulation of stress-related changes has been demonstrated. However, the mechanisms by which these factors influence each other are poorly understood, and there are currently no established robust biomarkers of stress susceptibility. To determine the metabolic and microbial signatures underpinning physiological stress responses, we compared stress-sensitive Wistar Kyoto (WKY) rats to the normo-anxious Sprague Dawley (SD) strain. Here we report that acute stress-induced strain-specific changes in brain lipid metabolites were a prominent feature in WKY rats. The relative abundance of Lactococcus correlated with the relative proportions of many brain lipids. In contrast, plasma lipids were significantly elevated in response to stress in SD rats, but not in WKY rats. Supporting these findings, we found that the greatest difference between the SD and WKY microbiomes were the predicted relative abundance of microbial genes involved in lipid and energy metabolism. Our results provide potential insights for developing novel biomarkers of stress vulnerability, some of which appear genotype specific.Item Worms and welfare: Behavioural and physiological changes associated with gastrointestinal nematode parasitism in lambs.(Elsevier B.V., 2023-10-27) Hempstead MN; Waghorn TS; Gibson MJ; Sauermann CW; Ross AB; Cave VM; Sutherland MA; Marquetoux N; Hannaford R; Corner-Thomas RA; Sutherland IAParasitism with gastrointestinal nematodes (GIN) is a worldwide issue impacting negatively on animal production, health, and welfare. Therefore, early diagnostic signs of parasitism are required to allow for timely interventions. The objective of this study was to evaluate the behavioural and physiological changes in lambs associated with GIN infection. We used 30, 8-month-old Romney-cross wethers, that were administered anthelmintics until faecal egg counts (FEC) were zero and housed in an indoor facility. The study lasted 9 weeks, which comprised a 3-week pre-treatment, and a 6-week treatment phase. Lambs were randomly assigned to one of two treatments (n = 15/treatment) trickle-dosed with: 1) 1500 infective third stage larvae (L3) three days/week for 6 weeks (27,000 total L3; challenged), or 2) water 3 days/week for 6 weeks (control). Within each pen there were 5 pairs of lambs (balanced for liveweight), with each pair comprising a challenged and control lamb. Blood, faecal, and saliva samples were collected 1 week pre-treatment and weekly for 6 weeks of treatment. Behaviour was observed (e.g., feeding, lying, standing) from video-camera recordings using scan sampling every 5 min for 8 h, 1 day pre-treatment and on the day immediately prior to physiological sampling across the 6-week treatment phase (7 days in total). Accelerometers were attached to each lamb to continuously monitor behaviour from 3 weeks pre-treatment and for the remainder of the study. Liveweight, body condition, faecal soiling and faecal consistency scoring were performed weekly as was lipidomic analysis of plasma samples. From week 2 of treatment, challenged lambs spent less time feeding and more time lying than control lambs until week 5 of treatment (P ≤ 0.01). At week 3 of treatment, elevated lipids (mainly triglycerides and phospholipids), loose faeces and faecal soiling around the anus were observed in challenged lambs compared with controls (P ≤ 0.05). From week 4 of treatment, FEC were elevated in the challenged compared to control lambs (P ≤ 0.05). There was also lower liveweight gain at 4 and 5 weeks of treatment in the challenged lambs compared with control lambs (P ≤ 0.05). These results show a clear timeline of changes in behaviour (e.g., feeding and lying), lipids such as triglycerides, and digestive function (e.g., faecal soiling) suggestive of GIN subclinical disease, which show promise for use in future studies on early identification of subclinical GIN parasitism in lambs.Item Associations between dietary patterns and an array of inflammation biomarkers and plasma lipid profile in postmenopausal women.(BioMed Central, 2023-05-12) Ilesanmi-Oyelere BL; Kruger MCOBJECTIVE AND DESIGN: In this cross-sectional study, evaluation of the association between four dietary patterns, nutrients and food intakes and an array of systemic inflammation biomarkers and lipid profile among 80 New Zealand postmenopausal women were conducted. MATERIALS: Eighty postmenopausal women participated in the study. A validated food frequency questionnaire was used to collect nutrients and food intake. Four dietary patterns were identified by principal component analysis (PCA) and plasma samples collected for inflammatory biomarkers and lipid profile measures. RESULTS: There were negative correlations between intake of dietary fibre, soluble and insoluble non-starch polysaccharides (NSP), vitamin C and niacin and with almost all the inflammatory markers for the whole group. Vegetables, tea/coffee and especially fruit intake were negatively correlated with the inflammatory biomarkers in the whole group. A high intake of Pattern 1 (potato, bread, and fruit pattern) was associated with a low risk of high interferon (IFN)-α2, IFN-λ, interleukin (IL)-6 and IL-8 levels while a high intake of Pattern 3 (fast-food pattern) was associated high risk of IFN-α2 levels. Multiple linear regression showed a negative correlation between Pattern 2 (soups and vegetables pattern) and levels of C-reactive protein (CRP) as well as ferritin. A positive association was observed between Pattern 3 (fast-food pattern) and CRP levels. Positive correlation was also observed between Pattern 2 and high-density lipoprotein (HDL) and total cholesterol (TC) levels, Pattern 4 (meat and vegetables pattern) was however negatively correlated with TC, low-density lipoprotein (LDL) and TC/HDL ratio. CONCLUSIONS: The result of this study reinforces the contribution and role of diet in modifying inflammation in postmenopausal women.Item Biophysical insights into modulating lipid digestion in food emulsions(Elsevier Ltd, 2022-01) Acevedo-Fani A; Singh HDuring the last decade, major scientific advances on understanding the mechanisms of lipid digestion and metabolism have been made, with a view to addressing health issues (such as obesity) associated with overconsumption of lipid-rich and sucrose-rich foods. As lipids in common foods exist in the form of emulsions, the structuring of emulsions has been one the main strategies for controlling the rate of lipid digestion and absorption, at least from a colloid science viewpoint. Modulating the kinetics of lipid digestion and absorption offers interesting possibilities for developing foods that can provide control of postprandial lipaemia and control the release of lipophilic compounds. Food emulsions can be designed to achieve considerable differences in the kinetics of lipid digestion but most research has been applied to relatively simple model systems and in in vitro digestion models. Further research to translate this knowledge into more complex food systems and to validate the results in human studies is required. One promising approach to delay/control lipid digestion is to alter the stomach emptying rate of lipids, which is largely affected by interactions of emulsion droplets with the food matrices. Food matrices with different responses to the gastric environment and with different interactions between oil droplets and the food matrix can be designed to influence lipid digestion. This review focuses on key scientific advances made during the last decade on understanding the physicochemical and structural modifications of emulsified lipids, mainly from a biophysical science perspective. The review specifically explores different approaches by which the structure and stability of emulsions may be altered to achieve specific lipid digestion kinetics.Item Physico-chemical properties and stability of lipid droplet-stabilised emulsions : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Manawatū, New Zealand(Massey University, 2022) Cheng, LirongIt is known that the structure of the interfacial layer impacts the stability and the function of emulsions. Hierarchical emulsions, known as droplet-stabilized emulsions (DSEs), were made from nano-sized primary oil droplets that coated with protein particles for potentially advanced functionality. In this study, the primary droplets were made of either rigid (whey protein microgel, WPM) or soft protein (Ca²⁺-cross-linked caseinate, Ca-CAS) particles. The structure of the protein particles and primary droplets in solution and at the oil-water interface were characterised; the oil exchange process between the surface and core oil droplets were examined, using light scattering, microscopy, small angle scattering, ultra-small angle scattering techniques, etc. The emulsification capacity of the primary emulsion has been shown to be improved by using soft and flexible protein particles, resulting in small droplet sizes and smooth interfacial layers of the DSE. The droplet-stabilised interfacial layer has been shown to provide DSE a good stability against coalescence during gastric enzymatic hydrolysis, long-term storage, and heating, as well as improved functionalities in the rate of the lipolysis during simulated intestinal digestion and the rheological properties at high oil content. Overall, this research provided new information on DSE physical-chemical properties and stability as affected by the structure of emulsifiers (protein particles and the subsequent primary droplets), digestion destabilisation, pH, storage time and temperature. The outcomes have potential for designing functional foods with improved active compound delivery and mechanical strength.Item Studies on formation, oxidative stability and plausible applications of food-grade 'droplet-stabilised' oil-in-water emulsions : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Riddet Institute, Massey University, Palmerston North, New Zealand(Massey University, 2019) Okubanjo, Samantha SewueseThis research was aimed at studying the structural characteristics, chemical stability and plausible functional applications of droplet-stabilised oil-in-water emulsions (DSEs). DSEs consist of oil-in-water droplets (the core) stabilised by submicron protein-stabilised oil droplets (the shell). The first objective was to increase our understanding of their structural properties and processing factors that contribute to DSE formation using food grade ingredients. To achieve this objective, milk protein concentrate (MPC) was chosen as the emulsifier. Four MPCs with different levels of calcium were used. The surface lipid (20 %) consisted of either a low (olive oil), medium (palmolein oil) or high (trimyristin) melting surface lipid. The core lipid (20 %) consisted of either a triglyceride (soybean oil) or pure fatty acid (linoleic acid). Protein-stabilised shell emulsions were processed either via the microfluidizer (170 MPa) or two-stage homogeniser (1st stage-20 MPa; 2nd stage-4 MPa). Results of the study showed that aggregated structure of protein emulsifier, shell droplet concentration, surface and core lipid types influenced the formation and structural properties of DSEs. The second objective focused on investigating the chemical stability of DSEs by evaluating their stability to oxidation and ability of its interfacial structure to protect polyunsaturated lipids incorporated within from oxidation. To achieve this objective, oxidative stability of high linoleic acid oil (safflower oil) stabilised by protein-coated low (olive oil), medium (palmolein oil) and high (trimyristin) melting lipid droplets was evaluated and compared with composition-matched conventional protein-stabilised safflower oil-in-water emulsion as well as a conventional protein-stabilised safflower oil-in-water emulsion (reference emulsions). Influence of physical state of high melting lipid droplets on oxidative stability of droplet-stabilised safflower oil emulsion was also evaluated. High linoleic acid (72.54% of total fatty acids) safflower oil (20%) was used because of its high susceptibility to oxidation. Olive oil (low acidity), palmolein oil and trimyristin were chosen because of their low susceptibility to oxidation. The study showed that safflower oil oxidation in DSEs was reduced by about 40-55% in comparison to conventional emulsions. High melting surface lipid DSEs provided better protection for safflower oil than low and medium melting surface lipid DSEs. The third objective aimed at improving our understanding of the influence of antioxidant’s location in emulsions on antioxidant performance. The study was also focused on exploring a plausible functional application of DSEs by incorporating a hydrophobic antioxidant in shell droplets (at the interface) of DSEs rather than in the interior of the core unsaturated lipid. To achieve this objective, butylated hydroxyanisole (BHA) a common commercially used synthetic hydrophobic antioxidant was chosen. BHA was incorporated either in shell droplets or core droplets of DSEs. The ability of BHA to counteract oxidation when incorporated in low (olive oil) and high melting (trimyristin) shell droplets of DSEs was evaluated and compared with BHA’s anti-oxidation performance when incorporated directly in core droplets (safflower oil) stabilised by low (olive oil) and high melting (trimyristin) shell droplets without BHA. Results of the study indicate that ability of BHA-in-shell DSEs to counteract oxidation of core safflower oil better than BHA-in-core DSEs is influenced by BHA’s concentration and transfer mechanism to reaction sites. The fourth and final objective was aimed at investigating mobility of a hydrophobic antioxidant incorporated at the interface of DSEs to establish their location after emulsification. The study focused on determining if a hydrophobic antioxidant incorporated in shell droplets remained localised within or migrated overtime to core droplets. The study also investigated the use of two techniques (saturated transfer difference (STD)-nuclear magnetic resonance and confocal Raman microscopy) to determine partitioning of antioxidants in DSE. To achieve this objective, confocal Raman spectroscopy technique was employed to probe antioxidant location without phase separation or destruction of DSE structure. Beta-carotene was chosen for the study for its excellent Raman scattering property. Beta-carotene was incorporated either in shell droplets (olive oil and trimyristin) or core droplets (safflower oil) of DSEs. Location and mobility of beta-carotene was evaluated after three days production. Beta-carotene migration from low (olive) and high melting shell droplets to core safflower oil was minimal. The present study provides processing conditions and structural characteristics required to form food-grade DSEs. The study confirms and establishes the potential of DSEs to effectively protect oxidation-sensitive lipophilic bioactives incorporated within from degradation and confirms the viability of concurrent incorporation of two different bioactives in DSEs emulsions by locating one bioactive in shell droplets and the second within the core.Item Variations in lipid composition of perennial ryegrass (Lolium perenne) and barley (Herdeum vulgare) with special reference to galactolipids : a thesis ... M. Agr. Sc.(Massey University, 1965) Gray, Ian KeithIn New Zealand, dairy cows are fed mainly on pasture in situ. This is in contrast to feeding practices in other countries where lactating cows are normally fed diets containing appreciable proportions of food products, other than fresh pasture. Although lipids form only 4-6% of the dry weight of leaf tissue (Hilditch and Williams, 1965) it has been estimated that a cow by eating 9 kg. of dry matter of grass per day may consume up to 700 g. of lipid (Hawke, 1963). The nature of dietary lipid and its modification in the rumen (Reiser and Reddy, 1956) is of particular interest as it may influence the composition of the depot and milk fats of ruminants. Only a few investigators have studied possible relationships between the composition of the milk fat and dietary lipids when ruminants are fed entirely on pasture species. (McDowall and McGillivray, 1963; Hawke, 1963).The latter worker demonstrated that young succulent short rotation ryegrass (Lolium multiflorum x Lolium perenne) contained a higher content of lipid (β of dry wt.) than mature grass which contained appreciable stalk material. Furthermore the lipid from the new growth contained higher proportions of linolenic acid and lower proportions of linoleic and palmitic acids. When pairs of monozygous twin cows were grazed on these two types of pasture, the cows feed on the young grass had higher levels of unsaturated fatty acids in the milk fat. This was thought to be related to higher levels of unsaturated fatty acids in the young grass and to the degree of hydrogenation of the unsaturated fatty acid components of the dietary lipid in the rumen. A large proportion of the dietary lipid of ruminants fed on pasture would consist of galactosyl glycerides since these components are the major lipids of photosynthetic tissue (Weenink, 1961 ; Sastry and Kates, 1964). Consequently the comparative levels of galactosyl glycerides and changes in their fatty acid composition in L. perenne leaf tissue of varying age has been investigated. The present investigation also includes a study of the effect of the light environment on the levels and composition of lipid, especially the galactolipids, and on the biosynthesis of fatty acids. [From Introduction]Item Lipolytic enzymes from the bovine rumen : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at Massey University(Massey University, 1970) Faruque, Abu J M Omar1.1. Lipid metabolism in the ruminants and significance of hydrolysis and hydrogenation in the rumen. The digestion pattern of ruminants differs from other mammals in that the food of ruminants is subjected to a microbial fermentation in the rumen before passing into the true stomach. Carbohydrates, proteins, organic acids and many other food constituents are attacked by the micro organisms in the rumen and as a result short-chain fatty acids (VFA), CO2 , CH4 , NH3 etc. are produced as the end product of microbial metabolism. This ruminal fermentation has a considerable effect on the metabolic processes of the animal and moreover the functions of the rumen microorganisms are intimately associated with certain metabolic disorders of the ruminant (Bryant, 1959) e.g. Ketosis, bloat etc. It is now generally believed that the organisms of functional significance in the rumen are protozoa and bacteria which are capable of growth under the anaerobic conditions prevailing. The rumen provides an ideal anaerobic environment for a large and diverse microbial population at a temperature of 39°-40°C. The pH of the ingesta is slightly acid and the bacteria are adapted to live between pH 5.5 and 7.0 (Hungate, 1966). It is apparent from earlier studies that the lipids of ruminants differ in several respects from those of non-ruminant herbivorous animals in particular. Occurrence of unusually high proportions of stearic acid and the presence of trans acids and isomeric forms of oleic, linoleic and linolenic acid in depot fats and tissue lipids are peculiar to ruminants. [From Introduction]