Authors:
Nana G
, Afoh RO
, Fombang ELL
, Ngone AM
, Nyindem AB
and Levai LD |
Abstract:
Grapefruit is the fruit of a subtropical citrus tree known for its bitter taste. The variety chiefly
grown in Cameroon is yellow skinned and ranges in diameter from 10 -20 cm. They are mainly
cultivated in the Southern parts of the country and transported to other regions by trucks and in
bags stacked on each other. Due to poor state of farm to market roads, especially in the rainy
season, delays in transportation create room for the development of a warm humid environment
in the bags. This gives suitable ground for the growth of the green mold, Penicillium digitatum
(Pers.: Fr.) Sacc., which further causes softening and decay of the fruits.
We studied the effect of temperature and bagging on the growth of P. digitatum on grapefruit
under different storage conditions for 14 days. Grapefruit was inoculated by P. digitatum and
water as control. Samples were subsequently packed in paper boxes, bagged and un-bagged
before storage at +4.C and room temperature (RT). Measurements were obtained for weight loss,
total soluble solid (TSS), degree of damage and decay development. Results showed that the
grapefruits inoculated with P. digitatum at room temperature both bagged and un-bagged were
completely decayed. However, storage at +4.C could retard the growth of P. digitatum as there
was no observable development of decay on the control that showed 40% and 65% decay
development when bagged and un-bagged respectively at RT. Storage in bagged conditions
reduced weight loss and prevented chilling injury when kept at +4.C. Results of TSS were not
remarkably changed after storage in all treatments while degree of damage was observed to be
higher in fruits which were stored at RT in un-bagged boxes. Combination of proper washing, bagging in polyethene and cold storage at +4.C inhibit the growth on and spoilage of grapefruits
by micro-organisms and will prevent chilling injury.
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