Separation of bromelain from crude pineapple waste mixture by a two-stage ceramic ultrafiltration process

•A two-stage ceramic ultrafiltration process was proposed to purify bromelain from pineapple waste.•The UF process managed to achieve 96.8% enzyme recovery in stage.•Bromelain purity increased up to 2.5-fold in stage 2.•Adjusting feed pH to 7.0 at room temperature enhanced flux and enzyme recovery.

Membrane technology is an attractive technique for purification of bromelain enzyme from pineapple. In this study, the feasibility of bromelain purification from pineapple's crude waste mixture (CWM) extract was investigated using a two-stage ceramic ultrafiltration (UF) scheme involving 75 kDa and followed by 10 kDa tubular ceramic membranes. Both UF stages were performed at specific processing conditions and determination on the permeate flux values and the extract properties of each UF stage were conducted. Observations were also employed at different feed pH and processing temperatures in both UF stages for processing optimization. Results showed the proposed technique managed to retain 96.8% enzyme recovery in the UF stage 1 and increase the bromelain purity up to 2.5-fold, which is within the targeted purity requirement, in the UF stage 2. The permeate flux values for UF stages 1 and 2 were 11.6 and 6.2 kg/m2 h, respectively. Higher VRF of the process in UF stage 2 leads to higher enzyme purity, thus the process can be adjusted depending on the enzyme final applications. For a better flux behaviour of the process and preservation of the bromelain enzyme during the process, this study suggests to adjust the feed pH to 7.0 and performing the process at room temperature (∼20 °C).

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