Optimisation of spray drying process in microencapsulated cream powder production

Use of Natural Polymers for the Encapsulation of Eugenol by Spray Drying

Background: Eugenol is a colourless or yellowish compound whose presence in clove essential oil surpasses the 75% of its composition. This phenylpropanoid, widely used as an antiseptic, anaesthetic and antioxidant, can be extracted by steam distillation from the dried flower buds of Syzygium aromaticum (L.). Due to its chemical instability in presence of light and air, it should be protected when developing a formulation to avoid or minimise its degradation. Methods: A promising approach would be encapsulation by spray drying, using natural coating products such as maltodextrin, gum arabic, and soy lecithin. To do so, a factorial design was carried out to evaluate the effect of five variables at two levels (inlet temperature, aspirator and flow rate, method of homogenisation of the emulsion and its eugenol:polymers ratio). Studied outcomes were yield and outlet temperature of the spray drying process, eugenol encapsulation efficiency, and particle size expressed as d(0.9). Results: The best three formulations were prepared by using a lower amount of eugenol than polymers (1:2 ratio), homogenised by Ultra-Turrax®, and pumped to the spray dryer at 35 m3/h. Inlet temperature and flow rate varied in the top three formulations, but their values in the best formulation (DF22) were 130 °C and 4.5 mL/min. These microcapsules encapsulated between 47.37% and 65.69% of eugenol and were spray-dried achieving more than a 57.20% of product recovery. Their size, ranged from 22.40 μm to 55.60 μm. Conclusions: Overall, the whole spray drying process was optimised, and biodegradable stable polymeric microcapsules containing eugenol were successfully prepared.

Optimization of spray drying conditions for improved physical properties in the production of enzyme-modified cheese powder

Enzyme-modified cheese (EMC), a cheese flavor additive with high-fat content, is preferably produced in powder form because of its long shelf-life and high industrial applicability. The physical properties of additives, especially with high-fat contents, are very important for their industrial usage, and the spray drying process conditions substantially determine the physical properties of powders. In this study, optimization of the spray drying process during the production of EMC powder was performed to improve the powder physical properties. The process factors were inlet temperature, feed flow rate, and aspiration rate, while the responses were selected as drying yield, Carr index (CI), wettability, surface fat content, and browning index (BI). The optimum spray drying conditions were calculated as 150°C, 9.1 mL/min, and 28.4 m³ /h for inlet temperature, feed flow rate, and aspiration rate, respectively. It has been determined that the spray drying conditions at low inlet temperature, medium feed flow, and aspiration rates in order to obtain improved powder physical properties should be preferred. Practical Application: Enzyme-modified cheese (EMC) is a widely used product in the development of foods with cheese flavor, and EMC in powder form offers various advantages for industrial applications such as ease in storage and transportation, long shelf-life, and product applicability, which mainly depend on powder physical properties. In powder production, spray drying is the principle process determining the powder physical properties, and optimization is essential for the desired physical properties. In this study, laboratory-scale optimization of EMC powder production was carried out, data was provided for scale-up studies, and the effects of processing conditions on powder physical properties were evaluated.