Extraction of Barberry Juice Based on the Filter Press Method: Study and Optimization of Some Influential Factors Based on Response Surface Methodology (RSM)

Barberry fruit is a native plant of Iran and belongs to the Berberidaceae family and is available in different species and colors. Iran is the first producer of barberry in the world. The eating fresh barberry fruits is limited due to spoilable, and the production of barberry-based products is one of the important methods for reduocing the waste of this fruit. Fruit juice production is one of the efficient methods in reducing agricultural waste. The filter press method is known as one of the common and effective methods for the juice extraction. In the present study, the effects of the layer height (at five levels of 15, 30, 45, 60 and 75 mm), cylinder diameter (at five levels of 40, 45, 50, 55 and 60 mm), and loading rate (at five levels 6, 12, 18, 24 and 30 mm/min) on the percentage of extracted juice from barberry, juice density, moisture content of pomace, final pomace porosity, specific energy consumption, and power consumption were studied and optimized. The results showed that the change in input variables resulted in changes in the percentage of extracted juice in the range of 33.9 to 51.8%, the juice density in the range of 1013.7 to 1047.2 kg/m3, the final pomace porosity in the range of 2.6 to 12.8%, and moisture content of pomace in the range of 19 to 41%. The results are suitable for optimizing the barberry water extraction process, using axial pressure devices and can be used to determine the optimal operating conditions of the juice making devices.