Chemistry Reference
In-Depth Information
Many types of fruit may be processed using this concept, such as strawberries, raspberries,
apples and pears, as well as tomatoes or any other pulpy fruit or vegetable, whether they are
fresh, frozen or thawed.
DSM recommends a pure pectinmethylesterase Rapidase FP Super produced from a
non-genetically modified strain of
A. niger
, or Rapidase PEP produced from a genetically
modified strain of
A. niger.
Both are destroyed above 85
◦
C during the final heating stage.
Fruit damage and disintegration are minimized thanks to pectate stability throughout the
manufacturing process. Yield, taste and appearance are improved.
11.7
VEGETABLE PROCESSING
World vegetable production reached some 1.3 bnmt in 2005. China was the top producer with
around 620 mmt, followed by India (105.5 mmt) and the USA (57.1 mmt). In volume terms,
potatoes (including sweet potato), tomatoes, watermelon, cabbage and onion are the top five
'vegetables' produced globally.
1
Vegetable juices are most commonly made from tomato,
carrot and red beet (though tomato is actually a fruit). V8 Vegetable Juice is one commercial
example, made mainly from tomatoes and the juices of seven additional vegetables: beets,
celery, carrots, lettuce, parsley, watercress and spinach. Tomato juice makes up 87% of the
total beverage. Consumer demand for vegetable juices is increasing and fruit and vegetable
juice combinations are becoming more popular. Numerous products came on the market
in 2007. These new drinks are cloudy and pulpy. It may be easy to produce tomato juice
without enzymes, but this is not the case for carrot, leek or cabbage. In fruit, pectin is the major
component to break down in order to facilitate juice extraction. But vegetables also have a
high content of dietary ligno-cellulosic fibres, which hinder juice extraction. Vegetable juice
processing therefore requires more cellulases in addition to pectinases to reduce viscosity
sufficiently for juice extraction using a decanter. Figure 11.10 outlines cloudy and concentrate
carrot juice processing.
Peclyve LI (Lyven) or Rapidase Vegetable Juice (DSM) is recommended for vegetable
juice extraction: they contain pectinases and cellulases. After blanching (to limit oxidation),
crushed vegetables are cooled to 50
◦
C and mixed with enzymes. After 1-2 h, the juice
is extracted using a decanter, pasteurized and possibly concentrated. The juice's carotene
content is not decreased by enzymes, and the cloud is stable for the duration of the juice's
shelf life.
11.8
NEW TRENDS AND CONCLUSION
Fruit and vegetable juices are natural, healthy beverages offering plenty of benefits to the
consumer: they contain many important nutrients, improve general well-being, counteract
negative aspects of a poor diet, have an appealing colour and flavour, and contain components
like antioxidants that prevent coronary disease and delay cell ageing. In line with rising
consumer diet and health awareness, the fruit and vegetable juices sector is expected to grow.
Average global per capita juice consumption is set to rise from 24 L in 2007 to some 30 L in
2010.
Enzyme producers are constantly making advances in microbiology, genetics, fermenta-
tion, enzymology and application research, which they share with end-users. High-quality
