Future research needs
Much research is still needed to develop minimally
processed fruit and vegetable products that have a high
sensory quality, microbiological safety and nutritional
value. Products intended for retailing are in particular
need of further development. It seems that it is possible
to achieve a shelf life of 7-8 d at refrigeration temperatures
(Y’C), but for some markets this is not enough: a
shelf life of 2-3 weeks is sometimes necessary. More information
about the growth of pathogenic bacteria and
the occurrence of nutritional changes in minimally
processed fruit and vegetables with long shelf lifes is
needed.
A characteristic feature of minimal processing is an
integrated approach, where raw materials, handling,
processing, packaging and distribution must all be properly
considered to make shelf-life extension possible.
New cultivars need to be selected and created or hybrids
adapted to meet the specific requirements of minimal
processing. The equipment used in unit operations, such
as peeling and shredding, needs further development so
that it can process produce more gently. There is no
sense in disturbing the quality of produce by rough
treatment during processing, and patching it up afterwards
by the use of preservatives.
Hurdle technology that makes use of natural preservatives,
such as inhibitors produced by lactic acid bacteria,
and the matching of correct processing methods and
ingredients to each other are two approaches that should
be applied more often to the minimal processing of produce.
Active-packaging systems and edible films, as well
as more-permeable plastic films that better match the
respiration activity of fruit and vegetables need to be
further developed. Exama et ~1.~~ have also proposed a
safety-valve system, which prevents excessive 0, depletion
and excessive CO, accumulation when a transient
temperature increase occurs. This type of system might
be particularly suitable for bulk and transport packages
of fruit and vegetable products.