Enzymatic and physical modification of milk fat: A review

A comprehensive review of medium chain monoglycerides on metabolic pathways, nutritional and functional properties, nanotechnology formulations and applications in food system

A large and growing body of literature has investigated the broad antibacterial spectrum and strong synergistic antimicrobial activity of medium chain monoglycerides (MCMs) have been widely investigated. Recently, more and more researches have focused on the regulation of MCMs on metabolic health and gut microbiota both in vivo and in vitro. The current review summarizes the digestion, absorption and metabolism of MCMs. Subsequently, it focuses on the functional and nutritional properties of MCMs, including the antibacterial and antiviral characteristics, the modulation of metabolic balance, the regulation of gut microbiota, and the improvement in intestinal health. Additionally, we discuss the most recent developments and application of MCMs using nanotechnologies in food industry, poultry and pharmaceutical industry. Additionally, we analyze recent application examples of MCMs and their nanotechnology formation used in food. The development of nanotechnology platforms facilitating molecular encapsulation and functional presentation contribute to the application of hydrophobic fatty acids and monoglycerides in food preservation and their antibacterial effectiveness. This study emphasizes the metabolic mechanisms and biological activity of MCMs by summarizing the prevailing state of knowledge on this topic, as well as providing insights into prospective techniques for developing the beneficial applications of MCMs to realize the industrialized production.

Bigel formulations based on sesame oleogel with probiotics alginate hydrogel: A novel structure for nutritious spreadable butter

As a replacement for saturated fats, bigel butter spread (BgBs) based on sesame oleogel and alginate hydrogel was developed. Morphology, oxidative stability, microbiological, chemical, and sensory analysis were assessed. The results demonstrated that unsaturated fatty acids were higher in cinnamon (73.87 %) than in plain (71.57 %) BgBs. The peroxide value was higher in plain (5.25 meqO₂/kg) than in cinnamon BgBs (4.29 meqO₂/kg). Cinnamon BgBs had 44.44 % more antioxidant activity compared to plain BgBs (40.20 %). Moreover, BgBs products kept their probiotic counts at >7 log cycles. The cinnamon BgBs had a lower microbial load than plain BgBs. The chemical composition of the BgBs products did not change significantly. But the pH values slightly dropped with the storage time. The sensory evaluation of plain and cinnamon BgBs did not significantly differ from one another. However, the period of storage and the addition of the cinnamon oil significantly affected the flavor ratings.

Effect of shearing-induced lipolysis on foaming properties of milk

BACKGROUND

The attraction of cappuccino-style beverages is attributed to the foam layer, as it greatly improves the texture, appearance, and taste of these products. Typical milk has a low concentration of free fatty acids (FFAs), but their concentration can increase due to lipolysis during processing and storage, which is detrimental to the foamability and foam stability of milk. There are contradictory results in reported studies concerning the effects of FFAs on the foaming properties of milk due to differences in milk sources, methods inducing lipolysis, and methods of creating foam. In this study, the foaming properties and foam structure of milk samples whose lipolysis was induced by ultra-turraxing, homogenisation, and microfluidisation (1.5-3.5 μ-equiv. mL^-1 FFAs) were investigated.

RESULTS

Compared with others, microfluidised milk samples had the smallest particle size, lowest absolute zeta potential, and highest surface tension; thus exhibited high foamability and foam stability, and very small and homogeneous air bubbles in foam structure. For all shearing methods, increasing FFA content from 1.5 to 3.5 μ-equiv. mL^-1 markedly decreased the surface tension, foamability, and foam stability of milk samples. The FFA level that led to undesirable foam structure was 1.5 μ-equiv. mL^-1 for ultra-turraxed milk samples and 2.5 μ-equiv. mL^-1 for homogenised and microfluidised ones.

CONCLUSION

Shearing-induced lipolysis greatly affected the physical properties of milk samples and subsequently their foaming properties and foam structure. At the same FFA level, lipolysis induced by microfluidisation was much less detrimental to the foaming properties of milk than lipolysis induced by ultra-turraxing and homogenisation. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Evaluation of the impact of hydrogen-rich water on the quality attribute notes of butter

The effects of washing raw butter with hydrogen-rich water (HRW), prepared with hydrogen (H₂) and/or magnesium (Mg), on butter quality were investigated in this research paper. During the washing process, titratable acidity (TA) decreased by 12% for all washed samples. During the storage period, TA increased by 28% and 93% (control), 14% and 58% (H₂), and 10% and 66% (Mg) for the 60^th and 90^th days, respectively. Peroxide value (mEq O₂/kg) increased to 2.76 and 8.83 (control), 1.92 and 7.25 (H₂), and 2.02 and 8.12 (Mg) for the 60^th and 90^th days. HRW samples showed the lowest acid degree value (ADV) and the highest color notes (L*, C*, and h). The HRW treatment of raw butter has shown improving effects on the product without any harmful residuals in the final product or the environment.

The Effect of Fat Content and Fatty Acids Composition on Color and Textural Properties of Butter

The textural properties of butter are influenced by its fat content and implicitly by the fatty acids composition. The impact of butter’s chemical composition variation was studied in accordance with texture and color properties. From 37 fatty acids examined, only 18 were quantified in the analyzed butter fat samples, and approximately 69.120% were saturated, 25.482% were monounsaturated, and 5.301% were polyunsaturated. The butter samples’ viscosity ranged between 0.24 and 2.12 N, while the adhesiveness ranged between 0.286 to 18.19 N·mm. The principal component analysis (PCA) separated the butter samples based on texture parameters, fatty acids concentration, and fat content, which were in contrast with water content. Of the measured color parameters, the yellowness b* color parameter is a relevant indicator that differentiated the analyzed sample into seven statistical groups; the ANOVA statistics highlighted this difference at a level of p < 0.001.

Effect of fat extraction methods on the fatty acids composition of bovine milk using gas chromatography

Milk fat is a complex natural fat and contains around 400 fatty acids. The objectives of this study were to extract fat from bovine milk using two different methods, including Bligh and Dyer and Mojonnier, and to determine the fatty acid content in the extracted fats using gas chromatography (GC). No differences (p > .05) were detected in the fat content and fatty acids content as a percentage of total fat (FA%TF) extracted using both methods. No differences (p > .05) were detected in some saturated fatty acids (SFAs) and unsaturated fatty acids (USFAs) extracted from both methods, such as C11:0 (undecylic acid), C16:0 (palmitic acid), C18:0 (stearic acid), C14:1 (myristoleic acid), and C16:1 (palmitoleic acid). However, the majority of SFAs were different (p < .05) in Mojonnier method as compared to Bligh and Dyer method and vice versa for USFAs. The short (6.54% vs. 5.95%) and medium (21.86% vs. 20.73%) chains FAs determined by GC were high in Mojonnier fat as compared to Bligh and Dyer fat, while the long-chain FAs were higher in the last (66.61%) relative to Mojonnier fat (65.51%). This study found that Mojonneir method has resulted in fewer errors. In contrast, the Bligh and Dyer extraction method has more experimental error, which led to decreasing the total fat, as well as was not able to detect C9:0.

Chemical and fatty acid composition of Manchego type and Panela cheeses manufactured from either hair sheep milk or cow milk

This study compared the chemical composition and fatty acid (FA) profile of Manchego type cheese and Panela cheese made from hair sheep milk and compared these with both types of cheese manufactured with cow milk as a reference. In addition, this study aimed to determine differences in sensory characteristics between Manchego type cheeses manufactured with either hair sheep milk or cow milk. A total of 25 and 14 Manchego type cheeses from hair sheep milk and cow milk were manufactured, respectively. In addition, 30 and 15 Panela cheeses from hair sheep milk and cow milk were manufactured, respectively. The chemical composition and FA profile were determined in all cheeses. In addition, a sensory analysis was performed in Manchego type cheeses manufactured from either hair sheep milk or cow milk. Moisture content was lower in Manchego type cheeses (37.5 ± 1.26 and 37.5 ± 1.26 g/100 g in cheeses manufactured from hair sheep milk and cow milk, respectively) than in Panela cheeses (54.0 ± 1.26 and 56.1 ± 1.26 g/100 g in cheeses manufactured from hair sheep milk and cow milk, respectively). Ash, protein, and sodium contents were higher in Manchego type cheeses than in Panela cheeses. Manchego type cheese manufactured from hair sheep milk contained more C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C18:2 cis-9,cis-12, total saturated FA, total short-chain FA, total medium-chain FA, total polyunsaturated FA, and de novo FA than Manchego type cheeses from cow milk. Total content of short-chain FA was higher in hair sheep cheeses (24.4 ± 1.30 and 19.6 ± 1.30 g/100 g in Manchego type and Panela cheeses, respectively) than in cow cheeses (8.89 ± 1.30 and 8.26 ± 1.30 g/100 g in Manchego type and Panela cheeses, respectively). Manchego type cheeses from hair sheep milk obtained higher scores for odor (7.05), texture (6.82), flavor (7.16), and overall acceptance (7.16) compared with those made from cow milk (6.37, 6.12, 6.17, and 6.83, respectively). In conclusion, both Manchego type cheese and Panela cheese manufactured with hair sheep milk had a similar chemical composition and contained higher levels of short-chain FA, total polyunsaturated FA, and de novo FA than those manufactured with cow milk.

The Influence of Dietary Fibers on Physicochemical Properties of Acid Casein Processed Cheese Sauces Obtained with Whey Proteins and Coconut Oil or Anhydrous Milk Fat

This study aimed to evaluate different fibers (acacia, bamboo, citrus or potato) on texture, rheological properties, color, density, and water activity of processed cheese sauces (PCS) based on acid casein, WPC80 and anhydrous milk fat or organic coconut oil. The interaction between the type of oil/fat, the fiber type and the fiber content was significant regarding almost all parameters studied. The computer vision system (CVS) showed that color changes of sauces could be noticeable by consumers. The main factor influencing the change in all products’ hardness was not fat/oil, but added fibers and their concentrations. The highest increase in hardness, adhesiveness and viscosity was observed in products with potato fiber. The value of storage modulus (G′) was higher than the loss modulus (G″) and tan (δ) < 1 for all samples. Different fibers and their amounts did not influence the water activity of cheese sauces obtained with organic coconut oil (OCO) or anhydrous milk fat (AMF).

Functionality of bovine milk proteins and other factors in foaming properties of milk: a review

For many dairy products such as cappuccino-style beverages, the top foam layer determines the overall product quality (e.g. their appearance, texture, mouthfeel and coffee aroma release rate) and the consumer acceptance. Proteins in milk are excellent foaming agents, but the foaming properties of milk are greatly affected by several factors such as the protein content, ratio of caseins to whey proteins, casein micelle size, pH, minerals, proteolysis, presence of low molecular weight compounds (lipids and their hydrolyzed products) and high molecular weight compounds (polysaccharides); milk processing conditions (e.g. homogenization, heat treatment and aging); and foaming method and temperature. These factors either induce changes in the molecular structure, charge and surface activity of the milk proteins; or interfere and/or compete with milk proteins in the formation of highly viscoelastic film to stabilize the foam. Some factors affect the foamability while others determine the foam stability. In this review, functionality of milk proteins in the production and stabilization of liquid foam, under effects of these factors is comprehensively discussed. This will help to control the foaming process of milk on demand for a particular application, which still is difficult and challenging for researchers and the dairy industry.

Negative Energy Balance Influences Nutritional Quality of Milk from Czech Fleckvieh Cows due Changes in Proportion of Fatty Acids

The objective of this study was to evaluate the influence of negative energy balance on fatty acids proportion in the milk of Czech Fleckvieh cows after calving. Milk quality was determined based on fatty acid group proportion. Milk quality was evaluated in relation to selected negative energy balance (NEB) traits: body condition change (DEC) and milk citric acid content (CAC) after calving. Milk samples (n = 992) were collected once per week from 248 Czech Fleckvieh cows during the first month of lactation. Fatty acid content (%) in milk samples was determined and results were grouped as saturated (SFA) (hypercholesterolemic or volatile fatty acids) or unsaturated (UFA) (monounsaturated or polyunsaturated). Our results showed that cows with a deep NEB produce milk that is healthier for human consumption. Cows with a more significant DEC or the highest level of CAC in milk had the lowest proportion of SFA and the highest proportion of UFA (p < 0.01). These cows experienced higher physiological stress after calving; however, they produced milk of higher nutritional quality. Nowadays, we can see preventive efforts to mitigate NEB periods as a result of modern breeding trends regarding vitality, robustness, or longevity.

Effect of the catalyst on the physical and aroma attributes of interesterified milk fat-vegetable oil blends

Abstract The present study aimed to verify the influence of the catalyst (sodium methoxide and the lipase from Rhizopus oryzae immobilized on a hybrid support - silica-polyvinyl alcohol) on the physical and aroma attributes of the products obtained from the interesterification of milk fat with vegetable oils (soybean and canola). The evaluation was carried out using an electronic nose (e-nose) and a texture analyzer. Interesterification reactions were carried out with binary blends (65% of milk fat and 35% of vegetable oil) using 0.75% sodium methoxide (60 °C for 60 min) and immobilized Rhizopus oryzae lipase at a fixed proportion of 500 units of activity per gram of blend (45 °C for 6 h). The results showed that the e-nose sensors discriminated satisfactorily the aromas of both raw materials and products and were able to distinguish them according to the catalyst used. In relation to the texture, both catalysts generated products with appropriate consistencies with satisfactory plasticity and spreadability at refrigerator temperatures.

Differential expression of fatty acid transporters and fatty acid synthesis-related genes in crop tissues of male and female pigeons (Columba livia domestica) during incubation and chick rearing

1. The growth performance of squabs reared solely by male or female parent pigeons was measured, and the changes of lipid content of crop milk and the expression profiles of genes potentially involved in lipid accumulation by crop tissues of parent pigeons were evaluated during incubation and chick rearing. 2. Squabs increased in body weight during 25 d of rearing, whereas both male and female pigeons lost weight after finishing rearing chicks, and the weight loss of male pigeons was significantly greater than that of female parent pigeons. Lipid content of crop milk from both parent pigeons gradually decreased to the crude fat level in the formulated diet after 10 d (R10) of chick rearing. 3. The gene expression of fatty acid translocase (FAT/CD36), fatty acid-binding protein 5 (EFABP) and acyl-CoA-binding protein (ACBP) in male pigeon crop tissue were the greatest at 17 d (I17) of incubation. In female pigeons, FAT/CD36 expression was the highest at I14, and both EFABP and ACBP expression peaked at I14 and R7. The expression of acetyl-CoA carboxylase and fatty acid synthase in male pigeons reached the maximum level at R1, while they peaked at I14 and I17, respectively in female pigeons. The gene expression of peroxisome proliferators-activated receptor-gamma (PPARγ) was the greatest at I17 in the male, while it was at I14 in the female. However, no regular changing pattern was found in PPARα gene expression in male pigeons. 4. These results indicated that male and female pigeons may make different contributions in rearing squabs. The gene expression study suggested that fatty acids used in lipid biosynthesis of crop milk probably originated from both exogenous supply and de novo synthesis. The sex of the parent pigeon affected the lipid content of crop milk and the expression profiles of genes involved in fatty acid transportation and lipogenesis.

Optimization of process parameters for supercritical fluid extraction of cholesterol from whole milk powder using ethanol as co-solvent

BACKGROUND

In spite of being highly nutritious, the consumption of milk is hindered because of its high cholesterol content, which is responsible for numerous cardiac diseases. Supercritical carbon dioxide using ethanol as co-solvent was employed to extract cholesterol from whole milk powder (WMP). This study was undertaken to optimize the process parameters of supercritical fluid extraction (SCFE), viz. extraction temperature, pressure and volume of ethanol.

RESULTS

The cholesterol content of WMP was quantified using high-performance liquid chromatography. The impact of the extraction conditions on the fat content (FC), solubility index (SI) and lightness (L*) of the SCFE-treated WMP were also investigated. The process parameters were optimized using response surface methodology. About 46% reduction in cholesterol was achieved at the optimized conditions of 48 °C, 17 MPa and 31 mL co-solvent; flow rate of expanded CO₂ , static time and dynamic time of extraction were 6 L min^-1 , 10 min and 80 min respectively. The treated WMP retained its FC, SI, and L* at moderate limits of 183.67 g kg^-1 , 96.3% and 96.90, respectively.

CONCLUSION

This study demonstrated the feasibility of ethanol-modified SCFE of cholesterol from WMP with negligible changes in its physicochemical properties. © 2016 Society of Chemical Industry.

The Effective Factors on the Structure of Butter and Other Milk Fat-Based Products

Butter and other milk fat-based products are valuable products for the dairy industry due to their unique taste, their textural characteristics, and nutritional value. However, an increased consumer demand for low-fat-based products increases the need for an increased essential understanding of the effective factors governing the structure of milk fat-based products. Today, 2 manufacturing techniques are available: the churning method and the emulsification method. The first is typically used for production of butter with a globular structure, which has become increasingly popular to obtain low-fat-based products, typically without presence of milk fat globules. The microstructure of milk fat-based products is strongly related to their structural rheology, hence applications. Structural behavior is not determined by one single parameter, but by the interactions between many. This complexity is reviewed here. Parameters such as thermal treatment of cream prior to butter making, water content, and chemical composition influence not only crystal polymorphism, but also the number and sizes of fat crystals. The number of crystal-crystal interactions formed within the products is related to product hardness. During storage, however, postcrystallization increases the solid fat content and strengthens the fat crystal network. The fat crystal network is strengthened by the formation of more and stronger crystal-crystal interactions due to mechanically interlinking of fat crystals, which occurs during crystal growth. Postcrystallization is directly linked to chemical composition. The initially observed microstructural difference causing different rheological behavior will disappear during storage due to postcrystallization and formation of more crystal-crystal interactions.

Influence of the colloidal structure of dairy gels on milk fat fusion behavior: quantification of the liquid fat content by in situ quantitative proton nuclear magnetic resonance spectroscopy (isq (1) H NMR)

Dairy gels (DG), such as yoghurts, contain both solid and liquid fats at the time of consumption, as their temperature rises to anything between 10 and 24 °C after being introduced into the mouth at 4 °C. The mass ratio between solid and liquid fats, which depends on the temperature, impacts the organoleptic properties of DG. As the ordinary methods for determining this ratio can only be applied to samples consisting mainly in fat materials, a fat extraction step needs to be added into the analytical process when applied to DG, which prevents the study of the potential impact of their colloidal structure on milk fat fusion behavior. In situ quantitative proton nuclear magnetic resonance spectroscopy (isq (1) H NMR) was investigated as a method for direct measurements in DG: at temperatures between 20.0 and 70.0 °C, the liquid fat content and the composition of triacylglycerols of the liquid phase (in terms of alkyl chains length) were determined. Spectra of isolated milk fat also enable the quantification of the double bonds of triacylglycerols. Statistical tests showed no significant difference between isolated milk fat and milk fat inside a DG in terms of melting behavior: the fat globule membrane does not seem to have a significant influence on the fat melting behavior.

Soft matter approaches to structured foods: from "cook-and-look" to rational food design?

Developments in soft matter physics are discussed within the context of food structuring. An overview is given of soft matter-based approaches used in food, and a relation is established between soft matter approaches and food technology, food creation, product development and nutrition. Advances in food complexity and food sustainability are discussed from a physical perspective, and the potential for future developments is highlighted.

Actual ratio of triacylglycerol positional isomers in milk and cheese

Actual ratios of triacylglycerol (TAG) positional isomers in human, rat, and cow milk fat and cow, buffalo, goat, and sheep cheese fat were analyzed using HPLC-UV-atmospheric pressure chemical ionization-MS/MS system equipped with an octacosyl silylation column or polymeric ODS column. We substituted cheese fats for milk fats in parts of our study because milks from ruminants, with the exception of cows, are difficult to get in Japan. The actual ratio of β-PPC (the TAG consisting of two palmitic acids (P) and one capric acid (C), with the palmitic acid located at the β position) and β-PCP in human milk was different from those in ruminants, with more than half of the medium-chain fatty acids located at the β position even though other fats possessed it mainly at the α position. Palmitic acid was mainly located at the β position for human milk and rat milk; however, the location in ruminant cheese fat was mainly at the α position. The location of fatty acids is thought to be very important for infant nutrition. Particularly, the location of palmitic acid in case of human milk and of medium-chain fatty acids in case of ruminant milk was very characteristic and is considered to be very important to the fatty acids in milk fat.