Pineapple Juice

Pineapple mill juice is the juice extracted from the waste trimmings from the cutting and canning of the valued pineapple core cuts. The juice extracted from most core trim cuts has about a 10% sugar content with high organic acid and organic nitrogen content.

Figure 1 outlines two process plans for the purification of a pineapple juice stream. The first, scheme 1A uses a double pass approach of a strong acid cation/weak base anion followed by a strong acid cation/weak base anion, where the strong acid resins are employed to deash (remove K⁺, Ca²⁺, Mg²⁺, etc.) and remove nitrogenous materials. The weak base anion resins remove the organic acid portion of the juice and reduce the color bodies. In a double pass system, the first two columns do the bulk of the work and the second pair provide back-up polishing and cleaning. When the first columns require change-out, the second set of strong acid/weak base anion resins can be moved to the lead position and the new resins put in their place. As an alternative, scheme 1B shows a process that uses strong acid cation, followed by weak base anion and then an adsorbent resin for the de-coloration process.

Scheme 1A is in most cases more economical; however, scheme 1B generally yields less colored product. Either case would be capable of providing a juice product that could be evaporated and used as canning syrup add-back.

Figure 1. Pineapple Juice