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UV Light Processing Effects on Quality, Nutritional Content, and Sensory Attributes of Juices, Milk, and Beverages
Published in Tatiana Koutchma, Ultraviolet Light in Food Technology, 2019
Milk is a natural colloidal emulsion of fat globules, as well as a hydrocolloid suspension of casein micelles, both dispersed in a water-based solution. The size of fat globules is ranging from 0.1 to 15 μm. The volume fraction of these fat globules and casein micelles, the particle size and shape, and particle–particle interactions contribute significantly to the properties of dairy products. Physical, optical properties, and composition of milk products are essential for developing of UV light-based processes for milk treatments. The differences in milk composition may impact the efficacy of light treatments. The available reports evaluated the UV and pulsed light (PL) effects in milk products of animal origin (cow, goat), colostrum, human milk, and milk products of plants origin (soy, almond, and tiger nut). As illustrated in Table 5.6, the gross composition of milk from the animals and humans differs widely, particularly with respect to fat and protein content.
Potential of Nanotechnology in Dairy Processing: A Review
Published in Megh R Goyal, Sustainable Biological Systems for Agriculture, 2018
Milk fat globule membrane is a blend of glycolipids, proteins, and phospholipids. Phospholipids in MFGM constitute more than 90% together with protein and 26-31% of total lipid percent.69 Milk fat globule membrane has the ability to decrease the interfacial tension at the interface of two liquids, and it behaves differently compared to milk proteins and, hence, is used for stabilization in emulsion formation. The unique nature of MFGM is that it demonstrates resistance to interfacial displacement when low molecular weight emulsifiers are used compared to milk proteins in stabilized emulsion system. However, the phospholipid content also contributes to decrease the interfacial tension and attribute to strong interfacial interaction between MFGM and the dispersed oil.68
Computerized Automation Controls in Dairy Processing
Published in Gauri S. Mittal, Computerized Control Systems in the Food Industry, 2018
Homogenization is the process by which the stability of milk fat emulsion is improved by decreasing the average diameter of milk fat globules. This prevents creaming or fat separation (due to the natural separation described previously). In homogenized milk, fat globules are more uniform in diameter and form a polydispersive system of milk fat with a narrow distribution [16]. The diameter of fat globules before homogenization can vary from 0.1 to 15 μm. In homogenized milk, about 85% of the fat globules are 0.1–2 μm and the rest are under 3 μm. Homogenization is performed at a very high pressure. Thus the main component of a homogenizer is a high-pressure pump that increases the pressure of milk from about 80–220 kPa at the inlet to a homogenizing pressure of 10–20 MPa. The homogenization temperature is normally 60–70°C. When the milk is forced through a narrow opening in the homogenizer head, its velocity becomes very high (about 200–300 m/s). As the milk leaves the homogenizer head, it makes impact at a high velocity on the inside of the homogenizer ring, and the fat globules are shattered.
Selective enrichment of milk fat globules using functionalized polyvinylidene fluoride membrane
Published in Preparative Biochemistry & Biotechnology, 2020
Aparna Verma, Ajay K. Sharma, Ayushi Agarwal, Saurav Datta, Kiran Ambatipudi
Milk is a complex biological fluid that has evolved as the main source of nutrition and immunological protection for suckling young and humans of all ages. Among the different milk components, lipids in milk exist as a unique emulsion in the form of spherical droplets of varying sizes known as milk-fat globules (MFG) and are stabilized by a physiologically functional milk-fat globule membrane (MFGM).[1] The fat globules are highly structured, with a triglyceride core surrounded by a trilayer biological membrane composed of Mucin 1 (MUC 1), Xanthine dehydrogenase/oxidase (XDH/XO), CD 36 (PAS IV), phospholipids and oligosaccharides.[2] These components of the MFGM are critical and have been reported to demonstrate enormous health benefits, such as the reduction of aberrant crypt incidence,[3] attenuation of lung injury by MFG epidermal growth factor8,[4] and anticancer activity of buttermilk against colon cancer in humans.[5] In addition, MFGM supplementation has been reported to modulate the gut microbiome in neonates and normalize intestinal development.[6]
Effect of outlet drying temperature and milk fat content on the physicochemical characteristics of spray-dried camel milk powder
Published in Drying Technology, 2019
Ahmed Zouari, Ítalo Tuler Perrone, Pierre Schuck, Frédéric Gaucheron, Anne Dolivet, Hamadi Attia, Mohamed Ali Ayadi
Besides, our findings suggested that, there was no direct effect of milk fat content on the bulk density of cow milk powder. However, increasing the milk fat content has directly decreased the bulk density of camel milk powder (p<.05, Table 5). It seemed like its particles underwent another development mechanism, during spray drying. In fact, compared to cow milk, Attia et al., 2000,[4] had reported that camel milk fat globules are smaller with a stiffer phospholipidic layer (about 2 and 4 µm for camel and cow milks, respectively). It can be suggested, that during spray drying, a minor part of fat globules (especially the largest ones) could be exposed to the free surfaces of whole or partially skimmed camel milk powders. This part of fat globules could form a discontinued hydrophobic layer. The major part of camel fat globules could be located in the core of particles, and they may preserve their initial structure. Such fat repartition could limit the water evaporation until the cracking of milk powder particles.
Energy usage in the manufacture of dairy powders: Advances in conventional processing and disruptive technologies
Published in Drying Technology, 2021
Maheshchandra H. Patil, Gaëlle Tanguy, Cécile Le Floch-Fouéré, Romain Jeantet, Eoin G. Murphy
Homogenization is often included in manufacturing processes as a means of emulsion stabilization, resulting in enhanced physical properties of dairy powders.[58,59] Homogenization, which is usually applied in two steps, reduces size of fat globules through means of shear forces and concomitant association of protein at the fat interface results in emulsion stabilization. Typically, fat globule size may be reduced by a factor of 10 and surface area may increase by a factor of 5–15.[58] This results in modification of concentrate properties which can affect the spraying performance. Location of the homogenizer (preheat/postheat treatment), homogenization pressure and concentrate DM are key factors that influence viscosity of concentrate. For instance, α-lactalbumin content in IMF powders was found to influence the interaction between homogenization position and heat treatment. Viscosity of model IMF concentrates (55% w/w DM) where α-lactalbumin constituted 12% of total protein was significantly (p < 0.05) lower when homogenized after heat treatment, compared to samples homogenized before heat treatment. In contrast viscosity of equivalent IMF concentrates, where α-lactalbumin constituted 48% of total protein, was not affected by homogenization location.[55] Viscosity of whole milk concentrates has been shown to be highly influenced by applied pressure.[60] Whole milk concentrate (42% w/w DM) viscosity was reduced due to homogenization at pressures up to 25 MPa, whereas homogenizing pressures higher than 25 MPa increased the concentrate viscosity.[60] In contrast, homogenization pressure (6.9–13.8 MPa) has been shown to have no significant impact on the concentrate viscosity of model IMF emulsions.[61] Bodenstab[62] demonstrated the influence of total solids during homogenization on viscosity of concentrate postevaporation. A two-stage homogenization at intermediate total solids (30% w/w DM) resulted in lower viscosity of whole milk concentrates, with the potential to subsequently implement high-solids drying.[62,63] Overall, it is clear that homogenization can significantly affect viscosity, however the exact effect may vary as a function of many factors such as composition, position of homogenization, pressures employed, etc.