ABSTRACT
The effect of osmotic treatments, carried out under different
conditions (osmotic solution concentration, at atmospheric pressure
or by applying vacuum pulse, addition or not of calcium lactate,
different dehydration levels of the fruit), on properties related with
fruit quality, was studied. Volatile profiles, colour and mechanical
properties and sensory acceptance of processed samples were
considered, as compared with fresh-cut product. Development of
minimally processed mango (20 ºBrix) throughout storage at 10 ºC
was analysed through respiration rates, microbial growth, physical
properties (colour and mechanical) and volatile profiles.
Short osmotic treatments applied with diluted solutions promoted
formation of volatile compounds, whereas long treatments applied
with concentrated/viscous solutions gave rise to a reduction in
volatile concentrations. The loss of cellular turgor (associated to
water loss) and the occurred structural changes produced a decrease
in the sample consistency. This decrease was mitigated when calcium
was applied in treatments with vacuum pulse. From the sensory point
of view, clarity, aroma and colour play an important role in the
sensory acceptance of the minimally processed mango. Treatments
carried out at atmospheric pressure without calcium give rise to the
preferred samples by panellists.
Shelf life of minimally processed mango (till 20 ºBrix) could be
established in different terms, depending on the considered quality
parameter and the kind of treatment. From the microbiological point
of view, the most stable samples were those processed with calcium,
at atmospheric pressure or by applying vacuum pulse. The osmotic
treatments reduced respiration rates in terms of O2 and CO2 of stored
mango samples, especially when processed with calcium. Mechanical
response was better preserved during storage when samples were
treated with calcium by applying vacuum pulse. Nevertheless, in
these cases, a decrease of hue, associated with sample browning was
detected. Storage produced changes in volatile profile of mango
samples, the increase in ethanol and ethyl acetate being remarkable,
especially in treatments carried out with calcium and vacuum pulse.