Novel methodology to enrich medium- and short-chain fatty acids in milk fat to improve metabolic health.

Dietary short- and medium-chain fatty acids have been shown to elevate circulating ketone bodies and confer metabolic health benefits. Cow milk fat contains these lipids in a balanced mix but in relatively low concentrations. Enriching them could amplify health benefits of dairy products.

Microstructural studies of imitation cheese with a shift in continuous phase.

When casein is replaced with starch in imitation cheese, the functionality changes. Three different microscopy methods were applied to understand the microstructural differences in the product depending on which component dominates the microstructure. Confocal Laser Scanning Microscopy (CLSM) for component identification.

A sustainable and regioselective synthesis of Hemi-bis(monoacylglycero)phosphates and bis(diacylglycero)phosphates.

A sustainable and green approach was developed for the scalable synthesis of uncommon naturally occurring phospholipid species, Hemi-bis(monoacylglycero)phosphates (Hemi-BMPs) and bis(diacylglycero)phosphates (BDPs) via the phospholipase D (PLD) mediated transphosphatidylation. PLD from . showed great substrate promiscuity for both phospholipids from different biological sources, and alcohol donors with diverse regiochemistry; monoacylglycerols with diverse fatty acyl structures (C12-C22), affording 74-92 wt% yields in 2 h.

Cold ultrafiltered or microfiltered milk retentates: A systematic comparison of the effects of compositional differences on their gelation functionality.

The colloidal stability of casein micelles suspensions prepared using ultrafiltration (UF) and microfiltration (MF) was studied by testing acid- and rennet-induced destabilization. Skim milk and 4× (based on volume reduction) concentrates were obtained by processing under similar conditions, at temperatures below 10°C. Concentrates were subjected to different levels of diafiltration (DF), resulting in samples with comparable casein volume fractions but different amounts of proteins and ions in the serum phase.

Proteolytic activity and heat resistance of the protease AprX from Pseudomonas in relation to genotypic characteristics.

AprX is an alkaline metalloprotease produced by Pseudomonas spp. and encoded by its initial gene of the aprX-lipA operon. The intrinsic diversity among Pseudomonas spp.

Assessment of rheological methods to study crystallization of palm oil fractions.

This study provides an evaluation of the use of rheology to characterize soft, semi-hard, and hard fats in relation to determine the crystallization onset, crystallization behavior, as well as microstructure development using either a plate-plate or a starch pasting cell (SPC). The results from this study demonstrate that when applying rheology to study fat crystallization, the results must be interpreted with care. The application of a plate-plate geometry allowed for sensitive evaluation of the initial nucleation phase, which was not possible with an SPC.

Freezing as a solution to preserve the quality of dairy products: the case of milk, curds and cheese.

When thinking of the freezing process in dairy, products consumed in frozen state, such as ice creams come to mind. However, freezing is also considered a viable solutions for many other dairy products, due to increasing interest to reduce food waste and to create more robust supply chains. Freezing is a solution to production seasonality, or to extend the market reach for high-value products with otherwise short shelf life.

Effect of frozen and refrigerated storage on proteolysis and physicochemical properties of high-moisture citric mozzarella cheese.

High-moisture mozzarella is one of the most-exported Italian cheeses worldwide, but its quality is affected by storage. Freezing is regarded as a solution to decrease product waste, extend market reach, and increase convenience, but its effect on quality has to be estimated. In this study, the details related to proteolysis, physicochemical properties, and sensory quality parameters of high-moisture mozzarella as a function of frozen storage (1, 3, and 4 mo) and subsequent refrigerated storage after thawing (1, 3, and 8 d) were evaluated.

Applicability of Confocal Raman Microscopy to Observe Microstructural Modifications of Cream Cheeses as Influenced by Freezing.

Confocal Raman microscopy is a promising technique to derive information about microstructure, with minimal sample disruption. Raman emission bands are highly specific to molecular structure and with Raman spectroscopy it is thus possible to observe different classes of molecules in situ, in complex food matrices, without employing fluorescent dyes. In this work confocal Raman microscopy was employed to observe microstructural changes occurring after freezing and thawing in high-moisture cheeses, and the observations were compared to those obtained with confocal laser scanning microscopy.

Disulfide bond formation is not crucial for the heat-induced interaction between β-lactoglobulin and milk fat globule membrane proteins.

During heat treatment of milk, β-lactoglobulin (β-LG) associates with the milk fat globule membrane (MFGM). The objective of this study was to examine different binding types that could be involved in this process. First, we tested the thiol-disulfide bond interchange between β-LG and MFGM by heating raw milk (87°C, 8 min) in the presence of different reagents capable of preventing this interaction, and then evaluated the presence of β-LG in resulting MFGM preparations by sodium dodecyl sulfate-PAGE.

Impact of industrial cream heat treatments on the protein composition of the milk fat globule membrane.

The impact of cream processing on milk fat globule membrane (MFGM) was assessed in an industrial setting for the first time. Three creams and their derived MFGM fractions from different stages of the pasteurization procedure at a butter dairy were investigated and compared to a native control as well as a commercial MFGM fraction. The extent of cross-linking of serum proteins to MFGM proteins increased progressively with each consecutive pasteurization step.

Effects of Different Fasting Durations on Glucose and Lipid Metabolism in Sprague Dawley Rats.

Overnight fasting of varying length is common practice when studying glucose and lipid metabolism in rats. However, prolonged fasting may influence insulin sensitivity, and it is unknown to which extent different fasting durations affect postprandial metabolism in rats. The purpose of this study was to investigate the effect of different fasting durations (6-, 12-, or 18-h) on fat tolerance and glucose tolerance in male Sprague Dawley rats.

Herd factors influencing free fatty acid concentrations in bulk tank milk.

Free fatty acid (FFA) concentrations can be elevated in raw milk due to improper handling and management at the dairy farm, and high concentrations of FFA can lead to off flavors in milk. This study aimed to describe how the herd production system, milking system, feeding and technological factors impact on FFA concentrations in bulk tank milk. FFA concentrations in bulk milk samples from 259 organic and 3326 conventional herds were analyzed by FT-IR during one year.

Thermal effects on IgM-milk fat globule-mediated agglutination.

The process of agglutination causes firm cream layers in bovine milk, and a functioning agglutination mechanism is paramount to the quality of non-homogenized milks. The phenomenon is not well-described, but it is believed to occur due to interactions between immunoglobulins (Ig) and milk fat globules. For the first time, this paper demonstrates how the process of agglutination can be visualized using confocal laser scanning microscopy, rhodamine red and a fluoresceinisothiocynat-conjugated immunoglobulin M antibody.

Pellet-free isolation of human and bovine milk extracellular vesicles by size-exclusion chromatography.

Studies have suggested that nanoscale extracellular vesicles (EV) in human and bovine milk carry immune modulatory properties which could provide beneficial health effects to infants. In order to assess the possible health effects of milk EV, it is essential to use isolates of high purity from other more abundant milk structures with well-documented bioactive properties. Furthermore, gentle isolation procedures are important for reducing the risk of generating vesicle artefacts, particularly when EV subpopulations are investigated.

Impact of triacylglycerol composition on shear-induced textural changes in highly saturated fats.

This study demonstrates a strong interaction between triacylglycerol (TAG) composition and effects of shear rate on the microstructure and texture of fats. Cocoa butter alternatives with similar saturated fat content, but different major TAGs (PPO-, PSO-, SSO-, POP- and SOS-rich blends) were evaluated. Results show how shear can create a harder texture in fat blends based on symmetric monounsaturated TAGs (up to ∼200%), primarily due to reduction in crystal size, whereas shear has little effect on hardness of asymmetric monounsaturated TAGs.

Effects of automatic cluster removal and feeding during milking on milking efficiency, milk yield and milk fat quality.

In order to increase milking efficiency, the effects of two different cluster take-off levels (200 and 800 g/min) and feeding vs. not feeding during milking were tested in a Latin square design study including 32 cows. Milk yield, milking time, milk flow and milking interval were measured and milk samples were analysed for gross composition, sodium and potassium concentration, free fatty acid (FFA) content, milk fat globule (MFG) size, MFG membrane (MFGM) material and fatty acid composition.

Covariance structures of fat and protein influence the estimation of IgG in bovine colostrum.

On-farm instruments for assessing colostrum quality are needed in order to ensure that the calf is supplied with enough IgG to avoid failure of passive transfer. The aim of this study was to evaluate methods for estimating the IgG concentration in cows' colostrum. This research included 126 colostrum samples from 21 Danish farms with different breeds, ensuring a broad variation pattern in IgG, total protein and fat concentration.

Protein denaturation of whey protein isolates (WPIs) induced by high intensity ultrasound during heat gelation.

In this study, the impact of high intensity ultrasound (HIU) on proteins in whey protein isolates was examined. Effects on thermal behavior, secondary structure and nature of intra- and intermolecular bonds during heat-induced gelling were investigated. Ultrasonication (24 kHz, 300 W/cm(2), 2078 J/mL) significantly reduced denaturation enthalpies, whereas no change in secondary structure was detected by circular dichroism.

The effect of butter grains on physical properties of butter-like emulsions.

Milk fat exists as globules in its natural state in milk. The potential of using globular fat to modulate the rheological properties and crystallization behavior in butter-like emulsions was studied in the present work. We conducted a comparative study of butter-like emulsions, with a fat phase consisting of 0, 10, 25, 50, or 100% anhydrous milk fat (AMF), the remaining fat being butter grains, and all samples containing 20% water, to obtain systematic variation in the ratio of globular fat.

Crystallization mechanisms in cream during ripening and initial butter churning.

The temperature treatment of cream is the time-consuming step in butter production. A better understanding of the mechanisms leading to partial coalescence, such as fat crystallization during ripening and churning of the cream, will contribute to optimization of the production process. In this study, ripening and churning of cream were performed in a rheometer cell and the mechanisms of cream crystallization during churning of the cream, including the effect of ripening time, were investigated to understand how churning time and partial coalescence are affected.

Multivariate data analysis for finding the relevant fatty acids contributing to the melting fractions of cream.

Background: The melting behaviour and fatty acid composition of cream from a total of 33 cows from four farms were analysed. Multivariate data analysis was used to identify the fatty acids that contributed most to the melting points and to differentiate between creams from different practical feeding regimes.

Results: It was demonstrated that the melting point of the medium melting fraction of milk fat was positively correlated with palmitic acid (C16:0), whereas it was negatively correlated with oleic acid (C18:1 cis9), conjugated linoleic acid (CLA cis9 trans11), vaccenic acid (C18:1 trans11), elaic acid (C18:1 trans9) and myristoleic acid (C14:1).

Appropriateness of culinary preparations of potato (Solanum tuberosum L.) varieties and relation to sensory and physicochemical properties.

Background: Appropriateness of potatoes for culinary preparations is defined as the optimal use of a given variety for a specific culinary preparation. The aim of this study was to examine the sensory attributes and physicochemical characteristics (dry matter content, starch properties, instrumental texture) of 11 potato varieties in relation to their appropriateness for boiling, oven-frying or mashing. The reproducibility of appropriateness was studied by including the effect of two growing conditions and yearly variation combined with internal references.

Effect of grazing fresh legumes or feeding silage on fatty acids and enzymes involved in the synthesis of milk fat in dairy cows.

The impact of fresh legume types or silage on the composition of milk fatty acids and transcription of enzymes involved in the synthesis of milk fat in cows was studied. Three groups of cows grazed high proportions of white clover, red clover and lucerne, respectively. A fourth group of cows was fed maize/grass silage.