Enzymes in fruit andvegetable processing
Enzymes play an important role in the processing of fruits and vegetables. In the United States alone, approximately 53% of the fruits on the market are processed: ~6% is canned, ~42% is juiced, ~2% is frozen, and ~4% is dried (U.S. Department of Agriculture, http://www.ers.usda. gov/Data/FoodConsumption/FoodAvailSpreadsheets.htm/). Due to the fast growth of the world population during the last two millennia, the number and type of food products have increased (i.e., more stable and convenience food products). Juices and other types of processed fruits and vegetables were developed to satisfy that need. The manufacturing of juices involves extraction of the liquid fraction and subsequent preservation for prolonged storage, resulting in either a clear or cloudy product. In the 1930s the use of enzymes to facilitate the ltering of extracted juices was introduced, with Pectinol K (of Röhm & Haas) as one of the rst products launched for the production of clear apple juice. Enzymes often lead to high cost reduction since less mechanical energy is required for processing, whereas juice yield might increase several percentages due to specic cell wall degradation by enzymes. Over the past decades, the use of enzymes for fruit and vegetable processing has grown into a mature industry with annual sales over $50 million. The range of applied enzymes (Table 12.1) has grown to increase yield during manufacturing but also to develop new products, applications, and health ingredients.