Using foam mat drying in the production of sugarcane molasses powder: optimization and kinetics of mass transfer

Abstract
Introduction: Sugarcane molasses is an undervalued by product of the sugar mill industry. It is Introduction: Sugarcane molasses is an undervalued by-product of the sugar mill industry. It is classified as generally recognized as safe (GRAS) and has been used as an alternative sweeter in the food industry (Deseo et al., 2020). Molasses is the final effluent obtained during the preparation of sucrose through a repeated process of evaporation, centrifugation, and crystallization from sugarcane juices (Jamir et al., 2021). It possesses special properties such as antioxidant, antimicrobial, weight loss, and treatment of anemia, and is used in cooking as a fermentation feed (Deseo et al., 2020; Jamir et al., 2021). Foam mat drying is a process used to convert liquid or semi-liquid foods into stable dried products. This is achieved by incorporating a large volume of gas in the presence of an edible foaming agent and/or stabilizer, followed by drying. Foam mat drying is suitable for drying viscous, sticky, heat-sensitive, and high-sugar food products that are difficult to dry using other tray drying techniques (Afifah et al., 2022). To ensure efficient foam mat drying, the foaming agent is used as a surfactant to reduce the surface tension between solid-liquid interfaces. Proteins are considered good and form a viscoelastic film around the bubbles, improving the powder's rheology (Brar et al., 2020). Xanthan gum, a natural polysaccharide, is one of the most important industrial biopolymers. It is widely used in various food materials for its emulsion stabilization, temperature stability, compatibility with food ingredients, and pseudo-plastic rheology properties. Xanthan gum is also utilized in pharmaceutical formulations, cosmetics, and agricultural products as a dispersing agent and stabilizer for emulsion/or suspension due to its stability to thicken aqueous solutions (Song et al., 2006). The stability of the foam is influenced by foam stabilizers such a gelatin, xanthan, and string time. It is crucial to optimize the process by using an appropriate concentration of foaming agent and foaming time (Mihe et al., 2023). Therefore, in the production of food powders, foam mat drying is a suitable and cost-effective alternative compared to traditional drying. This research was conducted to determine the optimal conditions for the production of sugarcane molasses powder using foam mat drying. Methodology: Molasses from Ahvaz sugarcane development and auxiliary industries company, as well as Sigma Alderich xanthan gum. Were used in this research. Egg white was also used a foaming agent which was obtained by purchasing whole eggs and separating the white. The eggs were purchased from the Mollasani local market. To prepare the foam, the molasses was brought to a brix level of 25. Then, xanthan gum was added at three different levels (0.1%, 0.125%, and 0.15%) and mixed thoroughly to create a homogeneous mixture. Following this, the egg white was added at specific concentrations (5%, 10%, and 15% w/w) and mixed using a household mixer (Moulinex, model BM6, Spain) for three different time periods (2, 4, and 6 min) (see table 1 for details). The resulting foam was placed in aluminum trays (6 mm in height, 48 cm in length, and 40 cm in width) and dried in a dryer (Heraeus, Germany) at a temperature of 50 °C. After leaving the dryer, it was powdered using a home grinder and stored in impermeable plastics until the tests were conducted. Results: Based on the obtained results, Wang and Singh's model was chosen as the best model to examine the drying kinetics of the samples at all drying temperatures and foam thicknesses. Using Fick's second law, the effective diffusion coefficient of humidity was calculated to be in the range of 2.07×10-8 to 18.5×10-8 (m2/s), with activation energy of 16.35 and 20.15 kJ/mol for thicknesses of 4 mm and 6 mm, respectively. Conclusion: The maximum drying process of sugarcane molasses foam was found to be in the descending speed stage. Wang and Singh's model was the best fit to describe the drying behavior of sugarcane foam. Additionally, increasing the temperature and foam thickness resulted in an increase in the effective moisture diffusivity. Therefore, sugarcane molasses powder can be utilized as a sweetener and additive in the formulation of various food products using the foam mat drying method.
Introduction: Sugarcane molasses is an undervalued by product of the sugar mill industry. It is Introduction: Sugarcane molasses is an undervalued by-product of the sugar mill industry. It is classified as generally recognized as safe (GRAS) and has been used as an alternative sweeter in the food industry (Deseo et al., 2020). Molasses is the final effluent obtained during the preparation of sucrose through a repeated process of evaporation, centrifugation, and crystallization from sugarcane juices (Jamir et al., 2021). It possesses special properties such as antioxidant, antimicrobial, weight loss, and treatment of anemia, and is used in cooking as a fermentation feed (Deseo et al., 2020; Jamir et al., 2021).
Introduction: Sugarcane molasses is an undervalued by product of the sugar mill industry. It is Introduction: Sugarcane molasses is an undervalued by-product of the sugar mill industry. It is classified as generally recognized as safe (GRAS) and has been used as an alternative sweeter in the food industry (Deseo et al., 2020). Molasses is the final effluent obtained during the preparation of sucrose through a repeated process of evaporation, centrifugation, and crystallization from sugarcane juices (Jamir et al., 2021). It possesses special properties such as antioxidant, antimicrobial, weight loss, and treatment of anemia, and is used in cooking as a fermentation feed (Deseo et al., 2020; Jamir et al., 2021). Foam mat drying is a process used to convert liquid or semi-liquid foods into stable dried products. This is achieved by incorporating a large volume of gas in the presence of an edible foaming agent and/or stabilizer, followed by drying. Foam mat drying is suitable for drying viscous, sticky, heat-sensitive, and high-sugar food products that are difficult to dry using other tray drying techniques (Afifah et al., 2022). To ensure efficient foam mat drying, the foaming agent is used as a surfactant to reduce the surface tension between solid-liquid interfaces. Proteins are considered good and form a viscoelastic film around the bubbles, improving the powder's rheology (Brar et al., 2020). Xanthan gum, a natural polysaccharide, is one of the most important industrial biopolymers. It is widely used in various food materials for its emulsion stabilization, temperature stability, compatibility with food ingredients, and pseudo-plastic rheology properties. Xanthan gum is also utilized in pharmaceutical formulations, cosmetics, and agricultural products as a dispersing agent and stabilizer for emulsion/or suspension due to its stability to thicken aqueous solutions (Song et al., 2006). The stability of the foam is influenced by foam stabilizers such a gelatin, xanthan, and string time. It is crucial to optimize the process by using an appropriate concentration of foaming agent and foaming time (Mihe et al., 2023). Therefore, in the production of food powders, foam mat drying is a suitable and cost-effective alternative compared to traditional drying. This research was conducted to determine the optimal conditions for the production of sugarcane molasses powder using foam mat drying. Methodology: Molasses from Ahvaz sugarcane development and auxiliary industries company, as well as Sigma Alderich xanthan gum. Were used in this research. Egg white was also used a foaming agent which was obtained by purchasing whole eggs and separating the white. The eggs were purchased from the Mollasani local market. To prepare the foam, the molasses was brought to a brix level of 25. Then, xanthan gum was added at three different levels (0.1%, 0.125%, and 0.15%) and mixed thoroughly to create a homogeneous mixture. Following this, the egg white was added at specific concentrations (5%, 10%, and 15% w/w) and mixed using a household mixer (Moulinex, model BM6, Spain) for three different time periods (2, 4, and 6 min) (see table 1 for details). The resulting foam was placed in aluminum trays (6 mm in height, 48 cm in length, and 40 cm in width) and dried in a dryer (Heraeus, Germany) at a temperature of 50 °C. After leaving the dryer, it was powdered using a home grinder and stored in impermeable plastics until the tests were conducted. Results: Based on the obtained results, Wang and Singh's model was chosen as the best model to examine the drying kinetics of the samples at all drying temperatures and foam thicknesses. Using Fick's second law, the effective diffusion coefficient of humidity was calculated to be in the range of 2.07×10-8 to 18.5×10-8 (m2/s), with activation energy of 16.35 and 20.15 kJ/mol for thicknesses of 4 mm and 6 mm, respectively. Conclusion: The maximum drying process of sugarcane molasses foam was found to be in the descending speed stage. Wang and Singh's model was the best fit to describe the drying behavior of sugarcane foam. Additionally, increasing the temperature and foam thickness resulted in an increase in the effective moisture diffusivity. Therefore, sugarcane molasses powder can be utilized as a sweetener and additive in the formulation of various food products using the foam mat drying method.
Keywords: foam mat drying, whipping time, drying kinetics, xanthan gum, sugar cane molasses