Effect of Vacuum Pressure and Flocculant Type on the Physicochemical Properties of Liquid Sugar from Coconut and Sugarcane Sap Using Vacuum Drying
Mochamad Bagus Hermanto 1*, Dea Nurinda Salsadila 2, La Choviya Hawa 2, Dimas Firmanda Al Riza 1, Dwi Setiawan 2

1 Department of Bioprocess Engineering, Faculty of Agricultural Technology, Universitas Brawijaya, Jl. Veteran, Malang 65145, Indonesia
2 Department of Agricultural and Biosystems Engineering, Faculty of Agricultural Technology, Universitas Brawijaya, Jl. Veteran, Malang 65145, Indonesia

Email : mbhermanto[at]ub.ac.id

Abstract

The production of liquid sugar from coconut sap and sugarcane sap is gaining importance in the food industry due to its ease of application. However, inconsistent product quality remains a major issue due to inefficient conventional processing methods. This study investigates the effects of vacuum pressure, flocculant type, and sap source on the physicochemical properties of liquid sugar to meet the quality criteria outlined in the Indonesian National Standard (SNI 8779 2019). A factorial completely randomized design was employed with three factors: vacuum pressure (100 mBar and 150 mBar), flocculant type (none, anionic, and phosphate-based P2-O5-), and sap type (coconut and sugarcane), each with three replications. Processing was conducted using a vacuum dryer at 70&#8239-oC, followed by analysis of Brix, water content, viscosity, pH, yield, and color. Results showed that a lower vacuum pressure (100 mBar) significantly increased yield (24.15%) and viscosity, while maintaining a water content of 32.17%. The phosphate-based flocculant (P2-O5-) produced the highest pure Brix value (70.80%) and enhanced color brightness. Sugarcane sap led to higher Brix (71.03%) and viscosity than coconut sap. The combination of 100 mBar vacuum pressure and phosphate flocculant was the most effective treatment for producing high-quality liquid sugar close to SNI standards. These findings underscore the importance of optimizing process parameters to improve clarity, stability, and sucrose concentration in the final product. This study also provides a foundation for scaling up production and offers potential directions for future research, including storage stability, energy efficiency, and the use of environmentally friendly natural flocculants.

Keywords: Liquid Sugar-Coconut Sap-Sugarcane Sap-Flocculant-Vacuum Drying-Physicochemical Properties

Topic: Agricultural and bioprocess engineering