Fat Droplet Size Research Articles

Correlations of Fat Content in Human Milk with Fat Droplet Size and Phospholipid Species

Fat globule size and phospholipid (PL) content in human milk (HM) were investigated. HM was classified into three groups depending on fat content (A < B < C). PL content (mg/100 g HM) was significantly higher in the C group (p < 0.05), indicating its positive relationship with HM fat content. When the PL content was normalized (mg/g fat), that of group A was significantly higher (p < 0.05) and fat droplet size in group C was slightly larger, suggesting that HM fat content is affected by fat droplet numbers to a larger extent than by fat droplet size. A correlation between PC and SM content in HM was observed regardless of fat content, while correlation between PE and either PC or SM increased in the order of C > B > A, hence the composition and content of PL species in HM varied according to its fat content.

Preparation of milk protein isolate/κ-carrageenan conjugates by maillard reaction in wet-heating system and their application to stabilization of oil-in-water emulsions

In this study, milk protein isolate (MPI) was conjugated with κ-carrageenan (CG) via the Maillard reaction in a wet-heating system at 65 °C for 48 h. As the Maillard reaction progressed, the browning intensity increased. The structural changes and formation of MPI-CG conjugates were confirmed through various analyses that proved their effective preparation via the Maillard reaction under the wet-heating system. Furthermore, we also investigated the rheological properties, fat droplet size distributions, and physical stability of emulsions stabilized by the MPI-CG mixture (0 h) immediately after mixing without heat treatment and MPI-CG conjugates with different reaction times. All emulsions exhibited shear-thinning behavior with lower flow behavior index values than 1 (n = 0.41–0.63), and their apparent viscosity (ηa,10) and consistency index (K) decreased with increasing reaction time. The MPI-CG conjugates produced larger fat droplets than the MPI-CG mixture (0 h), and the fat droplet size of the emulsions stabilized by the MPI-CG conjugates increased with increasing reaction time. Even so, the stability of the emulsions stabilized by the MPI-CG conjugates was improved when compared to the emulsion stabilized by the MPI-CG mixture (0 h), and the MPI-CG conjugate after a 12 h reaction time produced the most stable oil-in-water emulsion.

The effect of drying temperature and sodium caseinate concentration on the functional and physical properties of spray-dried coconut milk

This study investigated the effect of drying temperature on the stability and quality of spray-dried coconut milk. A low concentration (1-2% w/w) of sodium caseinate (SC) was used as emulsifying agent with 8-9% of maltodextrin. The spray drying temperature was varied from 140 to 180°C. Emulsions prepared at different SC concentration remained stable without phase separation for 24h. Higher the SC concentration produced smaller-sized of droplet and powder particles. The spray dried coconut milk has a skin-forming structure. Emulsion with low concentration of SC (1% w/w) is unstable during atomisation process due to re-coalescence of fat. Adding SC to the emulsion reduce the moisture content to less than 5%. However, drying the emulsions at 180°C gave negative impact to the powder properties. Some particles rupture and lead to high free fat content, high insolubility and larger fat droplet size. Presence of fleck is also noticed in the powder.

Influence of the melt holding time on fat droplet size and the viscoelastic properties of model spreadable processed cheeses with different compositions

Spreadable processed cheese (SPC) samples, with 30 and 40% (w/w) dry matter (DM) and 30, 40 and 50% (w/w) fat in dry matter (FDM), were produced with nine individual melt holding times (between 0 and 10 min) and stored for 30 days. Milk fat droplet size and viscoelastic properties were determined. In general, longer holding times resulted in decreased diameter of the milk fat droplets in all tested SPC samples. Furthermore, the size of the milk fat droplets decreased with increasing DM content and decreasing FDM content. Furthermore, for most of the produced SPCs, with the progress of the storage time, the G∗ values decreased over the first 2 or 3 min (of the applied holding time). In addition, prolonging the holding time and storage period resulted in an increase of the samples G∗ values. Increased DM content and decreased FDM content in SPC samples resulted in increased G∗ values.

Effect of processing of bovine milk on gastrointestinal symptoms and intestinal pressure in sensitive individuals

AbstractOver the last years, the consumption of unpasteurised milk has increased in popularity in the Western countries, despite the known risks associated with food-borne pathogens. Some people appear to experience milk-related gastrointestinal symptoms even when tested negative for lactose intolerance and milk allergy. In such cases, processing of milk, most often homogenisation or heat treatment, has been suggested to be involved in the induction of the gastrointestinal symptoms. Commercial milk is generally homogenised for the purpose of physical stability. Homogenisation reduces the size of fat droplets. Breaking of the fat globules creates new interface, which is covered with denaturated proteins. Further denaturation level of the proteins depends on the severity of the heat treatment. In this study entity, the effect of processing of bovine milk on the gastrointestinal symptoms in self-reported milk sensitive individuals was tested in two separate double blind crossover trials. Tested milks included raw milk (unprocessed), pasteurized milk, pasteurized and homogenized milk, and UHT treated and homogenized milk thus including milks at both end of commercially approved liquid milks in Finland. All milks came from the same herd of cows, which nulled the effect of genetic background and feeding of the cows. Ingestible pH-, pressure and temperature measuring probe was used to investigate gastrointestinal pressure. Self-reported diaries were used to measure perceived gastrointestinal symptoms. Additionally inflammation markers were studied from the plasma. In the first trial no significant difference was found in the amount of gastrointestinal symptoms or in the intestinal pressure after the consumption of native and processed milk. However, the obtained results on pressure in the large intestine (P = 0.068) as well as reported symptoms (P = 0.103) suggested that further studies in this area were needed. However, in the second trial where pasteurised, pasteurised and homogenised, and UHT -treated and homogenized milks were compared, the amount, severity or duration of the reported symptoms did not differ. This study demonstrates that the ingestible pressure-, pH and temperature measuring probe provided a novel possibility to study intestinal pressure in nutrition trials. The results of the present studies do not support the hypothesis that cows’ milk processing would induce gastrointestinal symptoms in milk sensitive but lactose tolerant subjects.

The stability and in vitro digestion of curcumin emulsions containing Konjac glucomannan

Konjac glucomannan (KGM) was used to characterize the structure of the curcumin emulsions stabilized with whey protein isolate (WPI). With an increasing concentration of KGM from 0.1% to 0.3%, the fat droplet size decreased significantly (p < 0.05) with increasing KGM content. The retention of curcumin in emulsions with KGM was significantly higher (p < 0.05) than the emulsions without KGM, after heating at 85 °C for 90 min. These two emulsions showed good stability in the pH range of 2–8 in addition to pH 5. Both emulsions with/without KGM were stable at 0–80 mM salt concentration, however the curcumin emulsion with KGM was unstable at 100 mM NaCl concentration. The droplet size analysis and microscopic observations indicated that the aggregation of fat droplets in these two emulsions occurred under simulated gastric fluid (SGF) conditions with a digestion time of 10 min. There were more undigested fat droplets in the curcumin emulsion with KGM than the emulsion without KGM under simulated intestinal fluid conditions after 120 min of digestion. The addition of KGM in WPI-stabilized curcumin emulsions slowed down the release rate of free fatty acids and curcumin from the emulsion droplets. These findings indicated that KGM could be used to achieve a controlled and sustainable release of bioactive compounds from emulsions.

Value of homodyned K distribution in ultrasound parametric imaging of hepatic steatosis: An animal study

Ultrasound is the first-line tool for screening hepatic steatosis. Statistical distributions can be used to model the backscattered signals for liver characterization. The Nakagami distribution is the most frequently adopted model; however, the homodyned K (HK) distribution has received attention due to its link to physical meaning and improved parameter estimation through X- and U-statistics (termed “XU”). To assess hepatic steatosis, we proposed HK parametric imaging based on the α parameter (a measure of the number of scatterers per resolution cell) calculated using the XU estimator. Using a commercial system equipped with a 7-MHz linear array transducer, phantom experiments were performed to suggest an appropriate window size for α imaging using the sliding window technique, which was further applied to measuring the livers of rats (n = 66) with hepatic steatosis induced by feeding the rats a methionine- and choline-deficient diet. The relationships between the α parameter, the stage of hepatic steatosis, and histological features were verified by the correlation coefficient r, one-way analysis of variance, and regression analysis. The phantom results showed that the window side length corresponding to five times the pulse length supported a reliable α imaging. The α parameter showed a promising performance for grading hepatic steatosis (p < 0.05; r2 = 0.68). Compared with conventional Nakagami imaging, α parametric imaging provided significant information associated with fat droplet size (p < 0.05; r2 = 0.53), enabling further analysis and evaluation of severe hepatic steatosis.

Cross-correlation analysis to quantify relative spatial distributions of fat and protein in super-resolution microscopy images of dairy gels

The advent of super-resolution microscopy allows microstructures of foods to be explored in new depths, which when coupled with quantitative image analysis can provide a powerful analytical tool. Herein, a methodology is presented and applied to use a 2D spatial cross-correlation analysis to investigate the relative spatial arrangement of protein and fat in acid induced whole milk gels where the milk is either non-homogenised or has been homogenised at either 10 or 25 MPa. Two-channel images were taken using super-resolution Stimulated Emission Depletion (STED) microscopy and confocal microscopy. A term has been derived to extract the typical distance from the fat droplet surface and to the local maximum protein distribution. The fat droplet size is determined through 2D spatial autocorrelation analysis. Methods of analysis are applied to global images and to region specific analysis focussing on individual fat droplets. Cross-correlation analysis has been empirically validated using generated images with precise spatial features corresponding to the features of interest in true microscopy images, over appropriate length scales. The protein microstructure, fat droplet size and distances between the fat droplets and protein network are characterised. There are significantly different distances between the fat droplets and protein network in the homogenised samples compared to the non-homogenised sample. The extracted separation distances are below the diffraction limit of light, highlighting the utility of super-resolution imaging.

Characterization of the physical, microbiological, and chemical properties of sonicated raw bovine milk

Innovative processing technologies, such as ultrasonication, can change the properties of milk, allowing for the improvement or development of dairy foods. Yet taking bench-scale equipment to pilot plant scale has been challenging. Raw milk, standardized to 3% fat and warmed to inlet temperatures of 42 or 54°C, was exposed to continuous, high-intensity, low-frequency ultrasonication (16/20 kHz, 1.36 kW/pass) at flow rates of 0.15, 0.30, and 0.45 L/min that resulted in resident times within the reaction cell of 6, 3, and 2 min per pass, respectively. Multiple passes (3, 5, and 7, respectively) were required to obtain a total exposure time of 14 to 18 min. Evaluation of fat droplet sizes, enzyme coagulation properties, and microstructure of milk and milk gels, as well as determining compositional and lipid properties, were conducted to determine the potential of the ultrasound system to effectively modify milk. Laser scanning particle sizing and confocal microscopy showed that the largest droplets (2.26 ± 0.13 µm) found in raw milk were selectively reduced in size with a concomitant increase in the number of submicron droplets (0.37 ± 0.06 µm), which occurred sooner when exposed to shorter bursts of ultrasonication (0.45 L/min flow rates) and at an inlet temperature of 54°C. Ultrasound processing with milk entering at 42°C resulted in faster gelling times and firmer curds at 30 min; however, extended processing at inlet temperature of 54°C reduced curd firmness and lengthened coagulation time. This showed that ultrasonication altered protein-protein and protein-lipid interactions, thus the strength of the enzyme-set curds. Scanning electron microscopy revealed a denser curd matrix with less continuous and more irregular shaped and clustered strands, whereas transmission electron microscopy showed submicron lipid droplets embedded within the protein strands of the curd matrix. Processing at inlet temperature of 54°C with flow rates of 0.30 and 0.45 L/min also reduced the total aerobic bacterial count by more than 1 log cfu/mL, and the number of psychrophiles below the limit of detection (10 cfu/mL) for this study. Ultrasonication exposures of 14 to 18 min had minimal effect on the milk composition, fatty acid profiles, and lipid heat capacity and enthalpy. The findings show that this continuous ultrasound system, which is conducive to commercial scale-up, modifies the physical and functional properties of milk under the parameters used in this study and has potential use in dairy processing.

Modifying the physical properties of butter using high-intensity ultrasound

The physical qualities of butter are affected by the physical properties of the cream used to make it. The objective of this study was to evaluate the effect of high-intensity ultrasound (HIU) on the physical properties of cream and butter. High-intensity ultrasound (frequency: 20 kHz, amplitude: 108 µm), often called sonication, was applied for 0, 10, 30, 60, and 90 s using a 1.27-cm-diameter tip to heavy cream (40% fat; 300 g) that was aged at 7.5°C with low agitation (40 rpm) for 90 min. Sonicated cream was churned at 7.5°C until butter grains were formed. The solid fat content (SFC), melting behavior, and average fat droplet size of cream were measured after HIU treatment. Butter was characterized by SFC and melting behavior immediately after production and was tested for SFC, melting behavior, and hardness after storage for 24 h at 5°C. High-intensity ultrasound did not affect the average fat droplet size of cream. Sonicating cream for 30, 60, and 90 s slightly decreased SFC due to the temperature increase (2-6°C) that occurred during HIU application. Two melting peaks were observed at approximately 17 and 33°C in all the cream samples. A significantly lower peak temperature was observed in cream sonicated for 10 s compared with creams sonicated for 30 and 60 s. A relatively shorter churning time of sonicated cream compared with nonsonicated cream was observed, possibly because HIU weakens the fat globule membrane. Two melting peaks were observed in all butter samples at approximately 16 and 33°C. Treatment with HIU for 10 to 60 s significantly increased the hardness of butter. When HIU was applied to cream for 10 s, the hardest butter was obtained, with the lowest onset temperatures and highest enthalpy values for both melting peaks. Treatment with HIU for 10 s promoted crystallization of low-melting-point triacylglycerols (TAG) during churning, which resulted in a harder material. Significantly lower enthalpy values for the high-melting-fraction TAG were observed in butters treated with HIU for 60 and 90 s compared with non-HIU-treated butter, which suggests that a longer duration of HIU promotes melting of high-melting-point TAG. The hardness of butter was correlated with the enthalpy values of the low-melting fraction and with total enthalpy values of fresh butter. However, further crystallization occurred in the butter during 24 h of storage at 5°C, and all differences in enthalpy values disappeared. In conclusion, exposure of cream to HIU can be used to modify the physical properties of butter, and the effects of HIU depend on the length of HIU treatment.

Quantitative ultrasound (US) imaging for fatty liver disease

Hepatic steatosis, which indicates the accumulation of fat in hepatocytes, is common and has a broad disease spectrum according to its pathogenesis and its severity. Clinically, the occurrence of non-alcoholic fatty liver disease (NAFLD), the most common type of hepatic steatosis, is strongly correlated with metabolic disease, and atherosclerotic cardiovascular disease. NAFLD having potential to progress into more advanced stage of fibrosis/cirrhosis has been the most common cause of chronic liver disease in Western counties, and the incidence of NAFLD has been known to be increasing. NAFLD is strongly associated with metabolic syndrome characterized by concomitant existence of obesity, diabetes mellitus, dyslipidemia and hypertension. Therefore, NAFLD can be considered as emerging major health problem. Traditionally, liver biopsy with histopathologic examination has been the gold standard method to diagnose and quantify hepatic steatosis. However, invasive nature with potential complication, small sample volume of biopsy specimen as well as high variability in measurement among the pathologists are major drawbacks of liver biopsy, and therefore, liver biopsy cannot be widely used for the evaluation of NAFLD. US which is widely available noninvasive imaging modality with no need of radiation exposure has been used for the screening of NAFLD for patients at risk, providing fairly good diagnostic accuracy to detect moderate to severe degree hepatic steatosis. However, limited diagnostic performances to detect mild degree hepatic steatosis and subjective nature examination with high intra- and inter-observer variability are major limitations of US. To overcome these limitations, several quantitative method using US images including hepatorenal ratio, ASQ and CAP have been implemented, showing promising results. Recently developed ultrasound based quantification tool for hepatic steatosis is controlled attenuation parameter (CAP) obtained from transient elastography (Fibroscan, Echosens, Paris, France). CAP assesses the degree of ultrasound beam attenuation by the intracellular fat vacuoles at the center frequency of M probe (3.5 MHz), and results are appeared as decibels per meter (dB/m), ranging from 100 to 400 dB/m. Considering NAFLD is usually associated with obesity as a manifestation of metabolic syndrome, failure to obtain CAP values in obese patients could be an important limitation of this technique. Acoustic structure quantification (ASQ) which analyses echo amplitude of ultrasound beam and evaluates changes in variance within region of interests has been introduced in clinical practice, and used for the evaluation of diffuse liver disease. Several initial studies using ASQ reported very promising diagnostic accuracy for assessing hepatic steatosis quantitatively both animal and human studies. A commercially available quantification method, acoustic structure quantification (ASQ), was introduced into clinical practice for the evaluation of diffuse liver disease. The method is based on statistical analysis of the difference between theoretical and real echo amplitude distribution. Theoretical echo amplitude distribution indicates that a speckle pattern in a certain liver region is approximated by a function of a Reyleigh distribution based on the assumption that the speckle pattern is generated only by ultrasonic interference of very small scattering objects that are located closer than the wavelength of US. However, real echo amplitude distribution of normal liver does not fit a Reyleigh distribution mainly because of the presence of small vessel walls. As hepaticsteatosis progresses, the real echo amplitude distribution more likely approaches the theoretical echo amplitude distribution with masking of the small structures, such as small vessel walls. In an animal model of hepatic steatosis, a significant correlation was observed between focal disturbance (FD) ratio, calculated by using ASQ, and either fat droplet area or fat droplet size. In a population of living donors for liver transplantation, acoustic structure quantification (ASQ) provides an excellent quantitative tool for hepatic steatosis, and there is a strong linear correlation (r = -0.87; P

Effect of different homogenisation methods and UHT processing on the stability of pea protein emulsion

Pea protein is a very popular source of edible plant-based protein among legumes. In this study, the stability of ultra high temperature (UHT) processed pea protein emulsion prepared from 0.5 and 1.0% (w/v) pea protein concentrate (PPC) by two different homogenisation methods of microfluidisation (500 Bar) and ultrasonication (ultrasonicated for 1, 3 and 5 min) was investigated. In addition, the emulsion properties (particle and droplet size, flocculation, coalescence, zeta potential, hydrophobicity and creaming index) of PPC emulsions before and after UHT treatment were measured. The overall heat transfer coefficient (OHTC) versus time graphs were stable during UHT processing for both microfluidised and ultrasonicated PPC emulsions that indicates no fouling and good stability under the thermal treatment condition. Freshly prepared emulsion using 0.5 and 1.0% PPC and ultrasonicated for 5 min showed creaming index of 5.73 and 8.39%, particle size of 0.96 and 1.53 μm respectively. In addition, the fat droplet size for the above samples measured 1.05 and 1.85 μm for larger fat droplets and 0.51 and 0.72 μm for smaller fat droplets, respectively. However, after UHT treatment this emulsion destabilised due to protein aggregation as indicated by the high flocculation index (13.22 and 103.35%), particle size (1.59 and 3.23 μm) and droplet size (1.30 and 2.53 μm, for large fat droplets and 0.90 and 1.22 μm, for small fat droplets). After UHT treatment the microfluidised PPC emulsion using 0.5 and 1.0% PPC were the most stable with small particle size (2.85 and 0.36 μm), high zeta potential (−56.36 and − 27.30) and low creaming index (3.87% and 4.97%), respectively as compared to ultrasonicated samples. Overall, this study revealed that UHT treatment improved emulsion properties of the microfluidised PPC emulsion compared to the ultrasonicated PPC emulsion.

Effect of cream aging temperature and agitation on butter properties

Aging of cream is an important process to manage production time and to produce butter with consistent quality. The objective of this study was to evaluate the combined effect of temperature (5, 10, and 15°C) and agitation rate (0, 40, and 240 rpm) during aging of cream on the physical properties of cream and butter in a model system. Cream's solid fat content (SFC), melting behavior, and droplet size distribution were measured during and after 90 min of aging. Butter physical properties such as melting behavior, water content, and hardness were measured. The effects of agitation on SFC and droplet size are dependent on aging and churning temperature. Solid fat content increased faster at 5°C, and the maximum SFC was the highest at this temperature. An effect of agitation on SFC was observed only when cream was aged at 15°C. Agitating cream at 40 rpm increased the droplet size regardless of aging temperature. Two melting peaks, medium melting fraction (MMF) and high melting fraction (HMF), were found in cream samples aged at 5 and 10°C, but only a HMF melting peak was seen in the cream aged at 15°C. The enthalpy of MMF in the cream aged at 10°C with 40 rpm and without agitation was significantly lower than that in samples aged at 5°C regardless of agitation rate. Butter can be formed only from cream aged under certain conditions during 14.5 min of churning, which are 5°C with high agitation and 10°C regardless of agitation level. Butter produced with cream aged at 5°C with high agitation showed significantly higher MMF and total enthalpy values. However, no significant difference in enthalpy values was observed among the butter samples made from the cream aged at 10°C. Further crystallization of MMF occurred in the butter produced with cream aged at 10°C during 24 h of storage at 5°C, whereas no further crystallization occurred in the butter made with the cream aged at 5°C with high agitation. The hardest butter was obtained when cream was aged at 5°C with 240 rpm and at 10°C with 40 rpm. Softer butter was obtained when cream aged at 10°C with 240 rpm was used. This butter also had the highest water content. This study shows that butter hardness can be tailored by changing the aging conditions of the cream. Cream can be aged at higher temperature with low agitation without altering the hardness of butter. These results will help dairy producers to optimize butter making processes to obtain desired properties in the final product.

Production of microencapsulated cream: Impact of wall materials and their ratio

Encapsulation wall material formulations were determined to obtain stable emulsions to produce high-quality microencapsulated powders. Fifty different emulsions were prepared using two types of proteins (sodium caseinate, whey protein concentrate) and five types of carbohydrates (maltodextrins having dextrose equivalency of 6 and 18, oxidised starch, lactose, and sucrose) in five different protein/wall material ratios (10–50%). Emulsions prepared with sodium caseinate resulted in higher viscosities and smaller fat droplet sizes than those prepared with whey protein. Furthermore, maltodextrins as the wall material, independent from dextrose equivalency, resulted in smaller fat droplet sizes than those using other carbohydrate sources. The emulsion prepared with maltodextrin (DE-18) and sodium caseinate of which the ratio was 20% in wall material was the most appropriate emulsion according to its lower percent creaming index, viscosity (3.48 cP at 35 °C and 3.53 cP at 45 °C), and average fat droplet sizes [D(90) = 9.11 μm].

Spatially Resolved Lateral Transmission Measurements to Characterize Changes in the Scattering Coefficient and the Anisotropy Factor.

A new setup is described to characterize the scattering coefficient and the scattering phase function of liquid media. The setup utilizes the basic idea of a spatially resolved reflectance measurement combined with a sophisticated illumination geometry. The sample is illuminated parallel and close to the interface of the sample and a glass window to get information from single scattered and multiple scattered light. By illuminating the sample with a fiber orientated with the axis parallel to the glass surface, small distances to the source can be examined unimpeded by the illumination beam. The derived information is, for example, not only sensitive to the concentration of the scatterers but also to the size of the scattering particles. We present the setup including the theory to describe the light propagation in the whole configuration using Monte Carlo simulations. The validation has been done with polystyrene microsphere dispersions with different scattering coefficients. As application for the developed setup, we show measurements of different milk samples which vary in concentration of fat, protein, and in fat droplet size during homogenization process. By measuring milk, we show the ability of the sensor to determine information about the scattering phase function without diluting the sample. For sensors in the dairy industry, a measurement with no pre-processing and no diluting of the sample is worthwhile, because this can be used to determine the fat and protein concentration on-line.

Antimicrobial Emulsifier-Glycerol Monolaurate Induces Metabolic Syndrome, Gut Microbiota Dysbiosis, and Systemic Low-Grade Inflammation in Low-Fat Diet Fed Mice.

Glycerol monolaurate (GML) is widely consumed worldwide in the food industry and is considered safe, but for chronic diseases, supporting scientific data remain sparse. This study investigates whether dietary GML induces metabolic syndrome, gut microbiota dysbiosis, and systemic low-grade inflammation. GML-induced occurrence of metabolic syndrome, gut microbiota alterations, and systemic low-grade inflammation are investigated. The results demonstrate that GML induced metabolic syndrome by significantly increasing the body weight, weight gain, food intake, body fat, fat droplet size and percentage of epididymal fat, serum triglycerides (TG), LDL, and atherogenic index, and decreasing the body muscle ratio, liver weight, and HDL, compared to the control (CON) group. Meanwhile, GML significantly changed the β-diversity and composition of gut microbiota and upregulated the circulating levels of serum LPS, IL-1β, IL-6, and TNF-α. Importantly, GML significantly decreased Akkermansia muciniphila and Lupinus luteus, and increased Bacteroides acidifaciens, Escherichia coli and the microbial DNA abundance of the ten predicated metabolism pathways involved in carbohydrate, amino acid, and lipid metabolism. Our results indicate that relatively low-dose GML consumption promotes metabolic syndrome, gut microbiota dysbiosis, and systemic low-grade inflammation, thereby calling for a reassessment of GML usage.

Development of fish-based model systems with various microstructures

The effectiveness of predictive microbiology is limited by the lack of knowledge concerning the influence of food microstructure on microbial dynamics. Therefore, future modelling attempts should be based on experiments in structured food model systems as well as liquid systems. In this study, fish-based model systems with various microstructures were developed, i.e., two liquid systems (with and without xanthan gum), an emulsion, an aqueous gel, and a gelled emulsion. The microstructural effect was isolated by minimising compositional and physico-chemical changes among the different model systems. The systems were suitable for common growth and mild thermal inactivation experiments involving both homogeneous and surface inoculation. Average pH of the model systems was 6.36±0.03 and average aw was 0.988±0.002. The liquid system without xanthan gum behaved like a Newtonian fluid, while the emulsion and the liquid containing xanthan gum exhibited (non-Newtonian) pseudo-plastic behaviour. Both the aqueous gel and gelled emulsion were classified as strong gels, with a hardness of 1.35±0.07N and 1.25±0.05N, respectively. Fat droplet size of the emulsion and gelled emulsion model systems was evenly distributed around 1μm. In general, the set of model systems was proven to be suitable to study the influence of important aspects of food microstructure on microbial dynamics.

The use of inline high-shear rotor-stator mixing for preparation of high-solids milk protein-stabilised oil-in-water emulsions with different protein:fat ratios

The emulsification of refined palm oil (RPO) in a continuous phase consisting of skim milk concentrate (SMC) and maltodextrin with a dextrose equivalent value of 17 (MD17) to produce fat-filled milk emulsions (FFMEs), was studied. A novel inline high-shear mixing (IHSM) method was used to produce emulsions, and three protein contents were investigated at a fixed RPO content of 12%: low (7.7%), medium (10.5%) and high (13%). Pressure drop measurement was used as an inline approach to determine viscosity using the Hagen-Poiseuille equation. In addition, offline viscometry, particle size and emulsion stability analyses were performed. Emulsion fat droplet size decreased significantly (P < 0.05) as a function of number of passes through the IHSM, due to an effective increase in residence time. Furthermore, inline pressure drop data demonstrated that the emulsification process displayed two distinct stages: (i) oil injection, and (ii) reduction in fat droplet size, irrespective of protein content.

Ultra-high pressure homogenisation process for production of reduced fat mayonnaise with similar rheological characteristics as its full fat counterpart

Abstract The potential of (ultra) high pressure homogenisation (UHPH) for production of emulsion (example of mayonnaise) with 28% of sunflower oil without thickeners and artificial emulsifiers was investigated. For purposes of comparison, a commercially available full fat (CFFM) and low fat mayonnaise (CLFM) were analysed. The emulsions were characterized by measuring the fat droplet size distribution, structure by confocal laser scanning microscopy (CLSM) and rheological properties applying flow and oscillatory tests one day after the processing. The droplet size and microscopic images of UHPH produced emulsion revealed smaller fat droplets and a more even distribution of components, compared to the CFFM and CLFM. Similar consistency index of UHPH low fat emulsion compared to the CFFM was obtained in pressure range from 250 to 300 MPa. In the same pressure range the UHPH emulsion showed higher firmness parameter compared to CFFM. The results of the study showed clear potential of UHPH technology for production of emulsion reduced in fat, free of additional thickeners and artificial emulsifiers. Industrial relevance text Mayonnaise is considered as one of the most popular sauces worldwide with high fat content. High pressure homogenisation (HPH) is a new continuous technique for preparation and stabilisation of emulsions, by means of significantly reducing the size of oil droplets and improving interactions between emulsifier and fat phase. This allows for production of oil-in-water (o/w) emulsions with reduced fat content. Further, emulsion with reduced amount of emulsifiers or completely free of thickeners can be produced. The results of this study could be of great importance for consideration of scale-up possibilities and future implementation of UHPH in food industry for production of low fat emulsions, having a clean label. Moreover, the process could stimulate interest in product development and optimisation of existing processes. A consumer friendly product reduced in fat and with clean label could be produced.

Oryzanol Modifies High Fat Diet-Induced Obesity, Liver Gene Expression Profile, and Inflammation Response in Mice.

In Western countries and China, the dietary habit of high calories usually results in hyperlipidemia, which is closely associated with cardiovascular diseases. In the study, we investigated the antihyperlipidemic effect of oryzanol and its molecular mechanism in the high fat diet (HFD) mouse model. In total, 60 ICR mice were randomly divided into control group, HFD group, and HFD+Ory group. The mice from the HFD+Ory group were additionally fed with 100 mg/kg of oryzanol by intragastric administration. Our data indicated that oryzanol treatment for 10 weeks significantly reduced bodyweight, liver weight, and adipose tissues weight of the mice; lowered the contents of total cholesterol (TC), triglycerides (TG), and low density lipoprotein-cholesterol (LDL-C); and elevated high density lipoprotein-cholesterol (HDL-C) in the plasma of HFD mice. Compared with the HFD group, H&E staining showed that oryzanol treatment decreased the size of fat droplets of liver tissues and the size of adipocytes. Gene chip data found that oryzanol administration caused 32 genes to increase expressions while 60 genes had reduced expressions in the liver tissues of HFD mice. IPA software was used to analyze the protein interaction network and found that transcript factor NF-κB located in the central role of network, meaning NF-κB may have important function in the lipid-lowering effect of oryzanol. Western blotting and RT-qPCR confirmed that lipid metabolism-related gene expressions were obviously regulated by oryzanol administration. Oryzanol also inhibited expressions of inflammatory factor in the liver tissues of HDF mice. Taken together, our data indicate that oryzanol treatment can regulate lipid metabolism-related gene expressions and inhibit HDF-caused obesity in mice.