Agriculture Reference
In-Depth Information
(fruit fl avoured drinks), many products will contain fruit juice within the typical
range of 2-10% in order to be legally described as 'fruit drinks'. When juice
contents are much higher, for example 20-50%, the description of a nectar may
sometimes be applied. The use of these descriptions varies depending on the local
labelling laws and the descriptions above relate primarily to the UK.
The usual fruit juice ingredient is concentrated up to about six times its original
strength to minimise transport and packaging costs as well as to reduce its
vulnerability to microbial spoilage. When concentrated juices are used as
ingredients, the amount must be reduced to take account of the amount of juice of
original strength that will be present after reconstitution by addition of water in
the soft drink.
The methods of extraction available for obtaining juices from fruit are many
and varied but depend broadly on the botanical structure of the fruit. There are
three main fruit categories that all require signifi cantly different early stage
processing, although after juice extraction, concentration and later stage processes
are similar. The three categories are:
•
Citrus fruit where the peel contains oil that must be recovered for both
economic and taste reasons
•
Stone fruit where the stone (pit) must be removed before juice can be expressed
from the pulp
•
Other soft fruit.
15.2.1 Juice production from citrus fruit
A typical citrus fruit processing operation is shown in Fig. 15.1. Whilst the
primary extraction of citrus juice is similar for all end uses, there are several
different products that may be produced to meet different uses and applications.
The largest volumes of citrus juices, particularly orange, are concentrated after
extraction from fruit, frozen and held at around −18°C until required. It is this
concentrated juice that is normally used when required as an ingredient in a
beverage where a particular juice content is needed.
Citrus juice, particularly orange, is increasingly used for direct consumption
without concentration and is usually described either as 'freshly squeezed' or 'not
from concentrate' (NFC). Freshly squeezed juices are typically packed without
pasteurisation or other processing, distributed and stored cold up to the point of
purchase. The typical shelf life is a few days. NFC juices are normally lightly
pasteurised, packed and stored cold but have a usual shelf life of several weeks.
These unconcentrated juices are invariably consumed directly and are not
normally employed as ingredients in other products.
15.2.2 Juice production from stone fruits
The processing of stone fruits differs from that of citrus in a number of respects
and is outlined in Fig. 15.2. Removal of the stone or pit is carried out early in the
Search WWH ::
Custom Search