Pineapple juice clarification by continuous dead-end microfiltration using a low-cost ceramic membrane

Pineapple juice clarification was performed by a continuous dead-end microfiltration process with low-cost ceramic membranes (M1-M3). Membranes were characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD), particle size distribution (PSD), and scanning electron microscopy (SEM). Membranes were observed to have contact angle (34-42(o)), membranes porosity (56 - 48%), average pore size (0.87 - 0.56 mu m), water permeability (3.00 x 10(- 6) - 1.07 x 10(- 6) m(3)/m(2)skPa), and corrosion resistance (1-1.2% weight loss) that are significant to be employed for juice clarification. Based on the comparative evaluations, membrane M3 was determined to be the best solution for juice clarification. The juice pH and total dissolved solids (TDS) remained unchanged during clarification, indicating that the membrane produced was promising. However, acidity density, total soluble solids (TSS), and vitamin C levels were reduced from 0.3072 +/- 0.06-0.3063 +/- 0.05%, 1.04 +/- 0.08 to 0.94 +/- 0.07 g/mL, 7.9 +/- 0.08 to 6 +/- 0.05(o)Brix, and 38.4 +/- 0.02 to 36.6 +/- 0.9 mg/100 mL, respectively. Also, minor changes in colour, and non-enzymatic browning index (NEBI) were observed. Total phenolic content, total flavonoid content, and antioxidant activity were dropped from 27.9 +/- 0.83-76.92 +/- 1.30 mg GAE/g, 79.23 +/- 1.37- 24 +/- 0.62 mg RE/g, and 85.52 +/- 1.56-75.34 +/- 1.26%, respectively. At a pressure of 345 kPa, the membrane provided a maximum permeate flux of 1.82 x 10(- 4) m(3)/m(2)s. The cake filtration model depicts the relevant fouling mechanism, which is reversible and the membrane may be readily cleaned. As a result, a membrane made from low-cost raw materials is recommended for the microfiltration of pineapple juice without enzymatic treatment.