88E-15 |
The utilization of apple pomace as a press aid in fruit juicing |
A. W. BATES, Biology Dept., William Smith College, Geneva, NY 14456 and J. S. Roberts, Dept. of Food Science & Technology, Cornell Univ., W. North St., NYSAES, Geneva, NY 14456. Fruits are a very important part of living a healthy lifestyle because they contain many beneficial nutrients. Soft fruits such as berries and grapes are highly perishable, and juicing is important because it produces a product with extended shelf life. Since berries are an expensive raw material, pressing efficiency is an essential unit operation to maximize juice yield. The screw press is commonly used in pressing soft fruits due to its continuous operation and its potential for high yields. Press aids are fibrous materials added to the fruit prior to juicing to increase yield and prevent the press from clogging. Rice hulls are the most common press aid for berries and paper is used in pressing Concord grapes, however they tend to leave a poor flavor in the juice. This research investigated the use of apple pomace, the waste product from juicing apples, as an alternative press aid. Drying kinetics of apple pomace was also investigated. The apple pomace was dried at 70 degrees Celsius in a drying chamber, milled and added to raspberries, strawberries, blueberries and grapes prior to pressing. The juice was evaluated for yield and flavor compared with juice pressed with rice hulls and paper. Desorption isotherms of the pomace were measured at 25, 35 and 45 degrees Celsius. The results showed that apple pomace compared as well as rice hulls and paper in juice yields, and resulted in a more favorable flavor of the juice than from the juice pressed with rice hulls. New York alone generates over 200 million pounds of apple pomace each year from apple cider and juice production. Though traditionally utilized as cattle feed, only a fraction is used due to the rapid spoilage of the wet pomace. This research has demonstrated an additional use of this high volume waste product.
Session 88E, Fruit & Vegetable Products: Processing
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