The Effect of Pretreatment (Spray Drying) on the Yield and Selected Nutritional Components of Whole Camel Milk Powder

Abstract

The effect of spray drying on the composition of camel milk powder was evaluated. A full factorial experimental design was used to see the effects of inlet temperature (160°C, 140°C, and 120°C), atomization pressure (800, 600, and 400 bar) and feed flow rate (5, 4, and 3 rev/s) on cyclone and vitamin C recoveries. Principal components analysis (PCA) was used to check classification of spray dried whole camel milk powders based on their processing conditions and multiple correspondence analysis (MCA) on the fatty acid profiles. The average proximate composition of the camel milk viz., fat, protein, lactose, and total solid were 3.0%, 3.21%, 3.01%, and 10.29% respectively. The powder yield (cyclone recovery) increased with increasing inlet temperature and decreasing feed flow rate. High outlet temperature and pressure decreased vitamin C recovery. As a result of PCA of the camel milk powders, they were classified into high heat treated and low heat treated milk powders while the MCA of the fatty acid profiles of camel milk powders were classified into high pressure and low pressure treated powders and it was concluded that higher atomization pressure caused increase in the content of fatty acids.Practical Application: Drying of camel milk (using spray drying) can extend its shelf life. The spray drying process must be optimized in order to retain the nutritional properties of the milk and the techno-functional characteristics of the powder. Here, the effect of the spray drying conditions on the yield and selected nutritional components of the milk powder was studied using a bench top spray dryer. However, there is need to translate these findings to an industrial volume dryer. These findings will play a big role in future spray drying operations since retention of important nutritional components is an important part of food processing.

Effect of spray drying on the fatty acids content and nutritional indices of buffalo powdered milk

“…Heat treatment (pasteurization and ultra-high temperature) can change the fatty acids profile (Habtegebriel et al, 2018;Javed et al, 2018). As observed by (Pestana et al, 2015) a decrease of the C4:0, C6:0 and C8:0; hence, the overall SFA also decreased.…”

“…The temperatures used by these authors were 75 °C (15 seconds) and 140 °C (3 seconds) for pasteurization and ultra-high temperature, respectively. Drying by spray drying transforms the fluid (milk) into droplets that are then exposed to hot air (inlet air of 140-180 °C) and cause the water-evaporate, which leaves the powder (Kim et al, 2009b;Batiston et al, 2012;Habtegebriel et al, 2018). The inlet air temperature used in our study was 180 °C.…”

“…These results are important for the buffalo dairy sector that has the assurance that the milk powder by spray dryer and its storage can be used as a technological tool to provide buffalo milk in seasonal shortages due to reproductive seasonality, however other studies should be done to create a specifics spray-drying conditions for the buffalo milk, as developed to others species (Habtegebriel et al, 2018;Javed et al, 2018).…”

“…The sensitivity of food to temperature process requires several studies regarding food science (Habtegebriel et al, 2018). On fact, each new product should be evaluated in its original features to know the effect of processing in its nutritional aspects, because fatty acids in foods are sensitive to processing temperatures.…”

“…On the spray dryer high temperature are used (Kim et al, 2009a) and several studies have examined the spray dryer effects on the physical and chemical characteristics (Murtaza et al, 2015) as well as the technological characteristics (Hammes et al, 2015;Borges et al, 2017) of the powder buffalo's milk. Studies with powder milk fatty acid were from bovine (Paez et al, 2006), goat milk (Batiston et al, 2012;Davis et al, 2017), ewes (Regula et al, 2005), or camel (Habtegebriel et al, 2018). The buffalo`s milk is different from the cow`s in fat, protein and minerals, among other contents and composition (Hinz et al, 2012;Medhammar et al, 2012).…”