What raw materials should be used to test juice yield when buying a commercial juicer?

Fix raw-material maturity, temperature, and pretreatment size during the yield test so equipment performance is not confused with raw-material variation. A sample demonstration is useful, but continuous production data is needed to verify repeatability and practical capacity. The supplier should identify any capacity limit caused by product temperature, moisture, particle size, or other material properties. For critical parameters, require signed records from both parties and retain the original data with the order documents. For equipment with change parts, list every required component and its adjustment range before placing the purchase order.