Conclusions
Human consumption of fresh fruit and vegetables is increasing due to
their reported natural and health promoting phytochemical contents. The
level of phytochemicals present in fruit and vegetables may vary depending
on several factors including cultivar variations, environmental conditions,
agronomic practices and harvesting factors. In addition, food
processing and product storage factors also influence the level of phytochemicals
present in the fruit and vegetables and their products. A thorough
assessment of pre-harvest factors is required to optimise the level of
phytochemicals in fruit and vegetables and their products. Pre-harvest
factors such as the variation of phytochemicalswithin cultivars following
harvesting at different maturity stages may play an important role. Studies
revealed that thermal processing may cause enzyme inactivation
which can lead to a reduction in degradation of phytochemicals. Storage
time and temperature are also important factors which may decrease
phytochemical content in the processed fruit and vegetable products.
Optimising pre-harvest factors may be difficult due to varying environmental
conditions and differences in farm management practices.
Therefore food processors need to pay particular attention to the selection
of cultivars with high phytochemical content. In addition, the loss
of phytochemicals is amajor concern for food processors during food processing
operations and subsequent storage of food products. Fruit and
vegetables should be cooked under suitable conditions of time and temperature
to avoid over cooking and hence leading to the destruction of
phytochemicals. This will vary greatly depending on the type of food
product and severity of treatment. However, novel processing techniques
may offer a potential alternative to reduce the thermal impact on thermally
unstable phytochemicals. Optimised storage conditions can subsequently
be employed after processing to further reduce the loss of
phytochemicals in raw and processed fruit and vegetables.