Influence of Dryer Type on Surface Characteristics of Milk Powders (original) (raw)
Related papers
Journal of Food Engineering, 2009
The effects of various spray drying conditions (feed solids content, drying temperature, degree of homogenization and initial droplet size) on the surface composition of industrial spray-dried milk powders (skim milk powder and whole milk powder) were investigated. Experiments were performed in a laboratory-scale spray drier and the surface compositions of the powders were measured using electron spectroscopy for chemical analysis (ESCA). For whole milk powder, the amount of surface free-fat was also measured as a complement to the surface composition estimated using ESCA. For both skim milk powder and whole milk powder, the surface composition of the powders was found to be determined to a large extent by the spray drying conditions employed. At higher feed solids content or drying temperature, less fat and protein appeared on the surface of the powders. Less redistribution of components seemed to occur within the drying droplet because of high viscosity and rapid crust formation. Increasing the number of homogenization passes reduced the fat globule size and consequently the amount of fat present on the powder surface. The initial droplet size did not have a significant effect on the range of particle sizes studied in this work. Strong interaction effects between the spray drying conditions were also found. The results suggest that a combination of spray drying conditions is necessary to control the surface composition of milk powders. Possible mechanisms behind the formation of the surface composition of industrial spray-dried milk powders were proposed based on the findings in this work and theoretical considerations.
How surface composition of high milk proteins powders is influenced by spray-drying temperature
Colloids and Surfaces B: Biointerfaces, 2010
High milk proteins powders are common ingredients in many food products. The surface composition of these powders is expected to play an essential role during their storage, handling and/or final application. Therefore, an eventual control of the surface composition by modifying the spray-drying temperature could be very useful in the improvement of powder quality and the development of new applications. For this purpose, the influence of five spray-drying temperatures upon the surface composition of the powders was investigated by X-ray photoelectron spectroscopy. The major milk proteins were studied: native micellar casein and native whey, both more or less enriched in lactose.
Exploring drying kinetics and morphology of commercial dairy powders
Journal of Food Engineering, 2015
Understanding the effect of the initial composition of a liquid feed on the spray drying process and morphology of powders is important in order to reduce the time and costs for process design, and ensure the desired properties of the final product. In this work, seven commercial dairy products with different fat content were selected. The effect of initial composition on drying time during single drop experiments was studied. The morphology of powder particles and the influence of morphology changes on the drying rate were investigated in order to assess the effect of fat content on the effective diffusivity of water in dairy products. Results show that fat content influences drying time and morphology of powder particles. The higher the fat content the longer the drying time and particles appear to be less shrivelled. Changes in morphology and the drying rate seem to be related. Two falling drying periods were observed for most of the products. During the first period the drops shrink spherically, while during the second period shrivelling occurs. The effective diffusivity of water shows that high fat contents lead to a lower diffusivity of water in the products.
Functionality of Milk Powders and Milk-Based Powders for End Use Applications—A Review
Newer variants of milk powders and milk-based powders are being produced are looking for prospective end users. Powders possess physical and functional properties that are of significance in its usage notably powder structure, particle size distribution, powder density, bulk density, particle density, occluded air, interstitial air, flowability, rehydration (wettability, sinkability, dispersibility, solubility), hygroscopicity, heat stability, emulsifying ability, water activity, stickiness, caking, and others. Some of the functional properties of significance to milk powders and milk-based powders are discussed in this review. Applications with regard to specific milk powders for reconstituted cheese making, coffee creamers, and those suited for milk chocolate and for the baking industry are described.
Microstructure and chemical composition of camel and cow milk powders’ surface
LWT
This study aimed at investigating the chemical composition and microstructure of spray dried camel and cow milk powders' surfaces with two different milk-fat contents (1 and 20g 100 g −1). The SEM (Scanning Electron Microscopy) micrographs showed that spherical particles with a 'brain'-type surface for both milk powders were produced. The surface roughness (Ra) of whole (WDMP) and skimmed (SDMP) camel milk powders (Ra = 7.6 ± 0.4 nm and 5.6 ± 0.7 nm, respectively) were significantly lower as compared with the partially skimmed (PSCMP) and skimmed (SCMP) cow milk powders. The XPS (X-ray Photoelectron Spectroscopy) analysis highlighted that the surface of skimmed camel milk powders contained twice the lactose amount (17.7 ± 0.8%) as compared to cow milk powders (8.7 ± 0.4%). Furthermore, both milk powders showed the overexposure of proteins and fats at their surfaces regardless of the fat content. The CLSM (Confocal Laser Scattering Microscopy) micrographs highlighted that most of the camel milk fat globules were encapsulated by the proteins near the powder surface. Camel milk fat behavior during particle formation was attributed to their lower size distribution and their higher crystallization temperature.
Comparison of Physicochemical Properties of Spray-dried Camel’s Milk and Cow's Milk Powder
In the present study, fresh raw camel and cow's milk were concentrated to 20-30% total solids, and then dried using a pilot spray-dryer. The effect of direction of feed on physicochemical properties camel milk powders on physicochemical characteristics of the various spray-dried milks were determined. Some of the examined parameters of spray dried milks were affected, such as the water activity which had low values (0.154 -0.208). Moreover, the degree of lightness was affected by direction of feeding, where co-current feeding gave the highest degree of lightness (97.73), when compared to counter current (93.82). The spray-drying samples also affected the solubility which recorded higher values of tested milk powder samples. The flowability was affected by the direction of feeding; the co-current feeding gave high values, when compared to counter-current feeding which gave less values (1.21-1.37). The yield was also affected, the spray-dried samples gave (68.84-88.20). The chemical analysis indicated that moisture, protein, fat, ash and acidity ranged 1.01-2.41%, 23.75-26.64%, 27.86-29.82% and 0.1-029%, respectively. The results show the importance of optimizing the drying process, in order to obtain products with better functional and physicochemical properties.
Impact of Spray Drying Parameters on Lactose-Free Milk Powder Properties and Composition
Journal of Agricultural Studies
Lactose-free milk powders are an interesting topic, as the industry still struggles with the enhanced stickiness of the material. To better understand this topic, an industrial scale spray-dryer was used to assess the influence of process parameters on the powder properties of lactose-free milk. A simple design of experiments was conducted varying the inlet temperature in combination with the atomization flow rate. The intention was to set different driving forces for drying in combination with the different surfaces are for mass transport. Yield is typically the process bottleneck, but from results, high inlet temperature combined with small droplet size resulted in a 50.73% yield. Powder's moisture contents were between 0.53% and 5%, and water activity between 0.21 and 0.43, being all values within a safety threshold for storage. From bulk and tap density results, all powders revealed to be cohesive with the Hausner ratio above 1.5. Color measurements revealed off white sample...
Journal of the Bangladesh Agricultural University, 2019
Spray drying is a method of drying powder via microencapsulated from liquid rapidly with hot temperature in order to increase the shelf life. Hence, the objectives of the study are to investigate the effect of spray drying temperature on the nutritional composition and physical properties of dry milk powder of Saanen goat milk reared in Sandakan using maltodextrin as binder. The experiment tested the inlet air temperature variation from 140°C - 220°C with triplicates. The result was analyzed by a one-way analysis variance (ANOVA) using the Statistical Analysis System (SAS) version 9.4. The results showed that there are significant (p<0.05) effects of inlet air temperature on dry milk powder in term of its protein content, fat content, moisture content and the sinkability of the milk powder. Among all of the treatments, the most sinkable temperature was at 140°C. Overall, the control powder, T0 = 180°C, however, is still preferable as nutritional value (for both protein and fat) s...
The optimisation of the spray drying process for low-phenylalanine skim milk as a dietary supplement for phenylketonurics was studied. The effects of basic parameters including the inlet air temperature (100, 150 and 200°C), feed flow rate (5, 10 and 15 mL min )1 ) and air flow rate (400, 600 and 800 L h )1 ) on the solubility and particle size of the low-phenylalanine skim milk powder were determined using response surface methodology. The optimum conditions have been obtained with inlet air temperature of 133°C, feed flow rate of 5 mL min )1 , and air flow rate of 800 L h )1 . With the optimum parameters, the predicted values for the solubility and mean diameter were 95.33% and 5.34 lm, respectively, and experimentally were 94.36 ± 1.62% and 5.50 ± 0.44 lm, respectively. The experimental and predictive values were closely related showing predictive accuracy of the models. P value <0.05 is significant at a = 0.05. Lack of fit is not significant at P value >0.05. Optimisation of solubility and particle size A. Amiri-Rigi et al.