Comparative activities of milk components in reversing chronic colitis.

Inflammatory bowel disease (IBD) is a poorly understood chronic immune disorder for which there is no medical cure. Milk and colostrum are rich sources of bioactives with immunomodulatory properties. Here we compared the therapeutic effects of oral delivery of bovine milk-derived iron-saturated lactoferrin (Fe-bLF), angiogenin, osteopontin (OPN), colostrum whey protein, Modulen IBD (Nestle Healthsciences, Rhodes, Australia), and cis-9,trans-11 conjugated linoleic acid (CLA)-enriched milk fat in a mouse model of dextran sulfate-induced colitis.

Phenotypic population screen identifies a new mutation in bovine DGAT1 responsible for unsaturated milk fat.

Selective breeding has strongly reduced the genetic diversity in livestock species, and contemporary breeding practices exclude potentially beneficial rare genetic variation from the future gene pool. Here we test whether important traits arising by new mutations can be identified and rescued in highly selected populations. We screened milks from 2.

Fatty acid profile differs between organic and conventionally produced cow milk independent of season or milking time.

Differing amounts of fresh forage and concentrates fed, and level of input contributes to the differences reported in fatty acid (FA) composition of organic and conventionally produced cow milk. In many previous studies designed to investigate this phenomenon, comparisons were made between grazed organic cows and housed conventional cows. In the present study, we have investigated differences between organic and conventional milk produced using year-round pasture grazing, as practiced in New Zealand.

Invited review: organic and conventionally produced milk-an evaluation of factors influencing milk composition.

Consumer perception of organic cow milk is associated with the assumption that organic milk differs from conventionally produced milk. The value associated with this difference justifies the premium retail price for organic milk. It includes the perceptions that organic dairy farming is kinder to the environment, animals, and people; that organic milk products are produced without the use of antibiotics, added hormones, synthetic chemicals, and genetic modification; and that they may have potential benefits for human health.

The influence of emulsion structure on the Maillard reaction of ghee.

Food systems, such as cream and butter, have an emulsion or emulsion-like structure. When these food emulsions are heated to high temperatures to make products such as ghee, the Maillard reaction forms a range of volatile flavour compounds. The objective of this paper was to unravel the specific influence of emulsion structure on the Maillard reaction pathways that occur during the cooking of ghee using model systems.

Expression variants of the lipogenic AGPAT6 gene affect diverse milk composition phenotypes in Bos taurus.

Milk is composed of a complex mixture of lipids, proteins, carbohydrates and various vitamins and minerals as a source of nutrition for young mammals. The composition of milk varies between individuals, with lipid composition in particular being highly heritable. Recent reports have highlighted a region of bovine chromosome 27 harbouring variants affecting milk fat percentage and fatty acid content.

Protein composition of different sized casein micelles in milk after the binding of lactoferrin or lysozyme.

Casein micelles with bound lactoferrin or lysozyme were fractionated into sizes ranging in radius from ∼50 to 100 nm. The κ-casein content decreased markedly and the αS-casein/β-casein content increased slightly as micelle size increased. For lactoferrin, higher levels were bound to smaller micelles.

Coacervates of lysozyme and β-casein.

Complexes are formed when positively charged lysozyme (LYZ) is mixed with negatively charged caseins. Adding β-casein (BCN) to LYZ leads to flocculation even at low addition levels. Titrating LYZ into BCN shows that complexes are formed up to a critical composition (x=[LYZ]/([LYZ]+[BCN]).

Analysis of phospholipids in infant formulas using high performance liquid chromatography-tandem mass spectrometry.

Phospholipids have been used widely in the food industry as emulsifiers, but it is their biological and nutritional function that has been the focus over recent years. The recognition of the importance of phospholipids and sphingomyelin for infant development has led to an increase in the number of infant formulas claiming to contain these complex lipid components. Therefore, the ability to measure these lipids in infant formulas and dairy-derived complex lipid ingredients for fortification purposes is important.

Changes in Maillard reaction products in ghee during storage.

Ghee (milkfat from heat clarification) was made using direct cream (DC), cream butter (CB) or pre-stratification (PS) methods and stored at 60°C, in air, for at least two weeks. Milkfat degradation, particularly oxidation, occurred in all types of ghee, resulting in increases in aldehydes and free fatty acids. However, there was little difference in fat degradation rates in each type of ghee.

Use of X-ray micro tomography to study the microstructure of loose-packed and compacted milk powders.

The use of X-rays to evaluate food microstructure has developed considerably in recent years. In this work we used X-ray micro tomography (XMT) to visualize the microstructure of loose-packed and compacted samples of spray-dried skim milk powder (SMP) and whole milk powder (WMP) and to quantify the proportion of both interstitial and occluded air voids in each sample. Visual scrutiny of the acquired XMT images showed details of the microstructure of the milk powders such as the spherical morphology of the particles, the size of the particles and internal air voids of various sizes.

Pressure-induced denaturation of β-lactoglobulin in skim milk: effect of milk concentration.

The effect of milk concentration (10-40% TS) on the kinetics of the pressure-induced denaturation of β-lactoglobulin (β-LG) was studied. The denaturation was found to be a second-order process at all milk concentrations and pressures. There was a change in pressure dependence of the rate constants for denaturation at about 300 MPa, and this effect became more pronounced as the milk concentration increased.

Microbiology of raw milk in New Zealand.

The results of this study demonstrate the occurrence of the non-spore-forming pathogens, Staphylococcus aureus, Escherichia coli (total count and O157:H7), Listeria, Campylobacter and Salmonella, in New Zealand's raw milk supply. Samples of raw milk were collected monthly within five major dairying regions over one year. Each month, samples from five randomly selected farm vats in each region were collected for analysis (297 samples in total).

A rapid analytical method for cholecalciferol (vitamin D3) in fortified infant formula, milk and milk powder using Diels-Alder derivatisation and liquid chromatography-tandem mass spectrometric detection.

A method for analysing vitamin D(3) (VD3, cholecalciferol) has been established and validated. This method is rapid and cost effective and is intended for use in quality control in the manufacture of fortified infant formulae and milk powders. Milk or reconstituted milk powder was solubilised in methanol and extracted in one step into isooctane, which was separated by centrifugation.

Facilitating high-force single-polysaccharide stretching using covalent attachment of one end of the chain.

Single polysaccharide force spectroscopy has yielded particularly interesting data, the interpretation of which requires the marriage of statistical-mechanical theories of polymer physics to the complexities afforded by possible force-induced conformational transitions of the constituent sugar rings. However, the difficulty of designing handles for the specific attachment of the different ends of polysaccharide chains to substrates, such as piezoelectric scanners, cantilevers or microbeads has meant that the majority of studies to date have been carried out with the polymer physisorbed to the substrates between which it is stretched, or at best chemically attached via bonds formed at uncontrolled locations along the length of the molecule. This means that the lengths of obtained polysaccharide stretches, as well as the forces that can be placed on the molecule without generating detachment, are generally smaller than those obtainable for polymers that offer the ability to be covalently attached to substrates specifically at their ends.

Pasteurization of milk: the heat inactivation kinetics of milk-borne dairy pathogens under commercial-type conditions of turbulent flow.

This is the first study to report kinetic data on the survival of a range of significant milk-borne pathogens under commercial-type pasteurization conditions. The most heat-resistant strain of each of the milk-borne pathogens Staphylococcus aureus, Yersinia enterocolitica, pathogenic Escherichia coli, Cronobacter sakazakii (formerly known as Enterobacter sakazakii), Listeria monocytogenes, and Salmonella was selected to obtain the worst-case scenario in heat inactivation trials using a pilot-plant-scale pasteurizer. Initially, approximately 30 of each species were screened using a submerged coil unit.

Effect of heat treatments and homogenisation pressure on the acid gelation properties of recombined whole milk.

The homogenisation pressure and the order of heating and homogenisation were varied in the preparation of recombined whole milks. The fat globule sizes decreased from ∼2 to 0.2μm as the homogenisation pressure increased from 50 to 850bar for samples heated before (HEHO) or after (HOHE) homogenisation.

Interaction of lactoferrin and lysozyme with casein micelles.

On addition of lactoferrin (LF) to skim milk, the turbidity decreases. The basic protein binds to the caseins in the casein micelles, which is then followed by a (partial) disintegration of the casein micelles. The amount of LF initially binding to casein micelles follows a Langmuir adsorption isotherm.

Quantification of bovine milk oligosaccharides using liquid chromatography-selected reaction monitoring-mass spectrometry.

Oligosaccharides are important components of milk with bioefficacy as prebiotics, anti-infectives, and immune system modulators and as a possible source of sialic acid for neural function. Bovine milk oligosaccharides are lower in concentration and lack the diversity of human milk oligosaccharides but could be a commercial source of milk oligosaccharides for pediatric foods. For this development, an ability to quantify the oligosaccharides is required.

Thermophilic bacilli and their importance in dairy processing.

The thermophilic bacilli, such as Anoxybacillus flavithermus and Geobacillus spp., are an important group of contaminants in the dairy industry. Although these bacilli are generally not pathogenic, their presence in dairy products is an indicator of poor hygiene and high numbers are unacceptable to customers.

Recovery of Cronobacter sakazakii from environmental surface swabbing materials using a 5-h enrichment procedure.

This study aimed to reduce the time taken to detect low numbers of Cronobacter sakazakii inoculated onto environmental swabs (100, 10 or 1 cfu per swab) using a simple plating procedure for application in a dairy testing laboratory. Three types of environmental swabs (Biolab FlexiSwab, gauze swabs and the Whatman SwabCheck Polywipe sponge) were inoculated with either Cron. sakazakii in single culture or Cron.

Analysis of phospholipids in rat brain using liquid chromatography-mass spectrometry.

The brain is a lipid-rich organ containing complex polar lipids including phospholipids (PLs) and sphingolipids. These lipids are involved in the structure and function of cell membranes in the brain. We developed a fast and efficient liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify five different classes of PLs [Choline glycerophospholipid (consists of phosphatidyl choline and plasmenyl choline in these samples), ethanolamine glycerophospholipid (consist of phosphatidyl ethanolamine and plasmenyl ethanolamine in these samples), phosphatidyl serine, phosphatidyl inositol, and sphingomyelin] in the brain tissues of 80-day-old Wistar rats.

Raman spectroscopic prediction of the solid fat content of New Zealand anhydrous milk fat.

The functionality of anhydrous milk fat (AMF) is determined from solid fat content (SFC) and triacylglycerol (TG) profiles, parameters traditionally measured using nuclear magnetic resonance and high pressure liquid chromatography respectively. Raman spectroscopy coupled with partial least squares (PLS) analysis has been assessed as an alternative method for SFC and TG class quantification. Sample temperature at which the Raman spectra were collected, method of spectral preprocessing and type of PLS analysis were all investigated and found to significantly affect the resulting calibrations (as parameterized by root mean square error of cross validation).

Semicarbazide is non-specific as a marker metabolite to reveal nitrofurazone abuse as it can form under Hofmann conditions.

Detecting illegal nitrofurazone treatment of food-producing animals has been undermined by the reliance on semicarbazide as a marker metabolite for analysis because, during processing, semicarbazide forms in a variety of foods not exposed to nitrofurazone by previously unexplained pathways. In this study, formation of semicarbazide was examined under dairy product processing conditions. Hypochlorite dosed into milk on an industrial scale, at concentrations extreme for unintentional residues, produced monochloramine, but, without pH adjustment, hypochlorite alone did not generate semicarbazide.