Journal of Mechanical Engineering Science and Technology ISSN 2580-0817 Vol. 6, No. 1, July 2022, pp. 34-39 34 DOI: 10.17977/um016v6i12022p034 Effect of Homogenization Pressure on Bacterial Cellulose Membrane Characteristic Made from Pineapple Peel Waste Muhamad Muhajir 1 , Heru Suryanto 1,2 , Yanuar Rohmat Aji Pradana 1 , Uun Yanuhar 3 1 Department of Mechanical Engineering, Faculty of Engineering, Universitas Negeri Malang, Jl. Semarang 5, Malang, Indonesia 2 Center of Excellence for Cellulose Composite (CECCom), Department of Mechanical Engineering, Universitas Negeri Malang, Jl. Semarang 5, Malang 65145, Indonesia 3 Department of Waters resources Management, Faculty of Fisheries and Marine Sciences, Brawijaya University, Jl. Veteran Malang, East Java, Indonesia *Corresponding author:heru.suryanto.ft@um.ac.id Article history: Received: 31 August 2021 / Received in revised form: 8 March 2022 / Accepted: 20 April 2022 ABSTRACT Many studies were conducted to maintain the environment by reducing the waste, especially pineapple peel waste. This study aims to explore the effect of various pressure of the homogenization process on bacterial cellulose membrane surface morphology and structure produced using extract of pineapple peel waste. The methods include the preparation of pellicle samples from the product of the fermentation process of Acetobacter xylinum using a medium from the extract of pineapple peel waste. Bacterial cellulose pellicles were crushed using a blender. Mashed bacterial cellulose pellicle was homogenized in High-Pressure Homogenizer with pressure variation of 150 bar, 300 bar, 450 bar, dan 600 bar and then cast into a mold. The bacterial cellulose solutions were dried in an oven at 60°C for 8 hours. The dried bacterial cellulose membrane was analyzed using XRD for the structure and SEM analysis for the morphology. The results indicate that the crystalline properties of BCM were shifted after being treated by various pressure processing in a High-Pressure Homogenizer. It was found that the High-Pressure Homogenizer with higher pressure reduced the peak intensity, decreased crystalline index from 87% to 70%, and decreased the degree of crystalline from 88% to 77% without changing the cellulose structure. The higher pressure of the homogenization process causes the porosity of the membrane to be decreased. Copyright © 2022. Journal of Mechanical Engineering Science and Technology. Keywords: Bacterial cellulose, high-pressure homogenizer, morphology, pineapple waste, XRD I. Introduction Cellulose is an abundant biopolymer resulted in almost plants. It is composed of many compounds such as lignin, pectin, and hemicellulose, so its need many process and energy to purify plant cellulose. In this case, bacterial cellulose (BC) offers a higher purity source of cellulose than plant cellulose [1]. BC is produced from bacteria secretion in a fermentation medium that acts as a nutrient source, and the most famous bacteria used in the fermentation process for producing BC is Acetobacter xylinum instead of Gluconobacter xylinum [2]. Nowadays, many studies have been conducted to maintain the environment by reducing waste. Agricultural waste has been used as carbon source for many applications. Indonesia is a big product of pineapple till to 200,000 tons per year [4]. Pineapple peels are types of substrates that can be utilized as a carbon source. Thus, it is big opportunities to develop pineapple peel waste as a nitrogen and carbon source [3] to produce BC. Therefore, this