Introduction. Vietnam is among the world's top 20 mango producing countries.
In this country, the ‘cat Hoa loc’ variety is predominant, with 17 692 ha under
cultivation with an annual production of 58 471 t; it is considered to be the best mango
variety in the Mekong delta. Ripening of the fruit is typically expressed by a skin colour
change from green to bright yellow. This variety is highly prized by local and foreign
consumers, but subject to different disorders, especially fruit fly infestations. Heat
treatment is a safe alternative to chemical treatments. It can impair mould development
and control fruit infestation by destroying fruit fly eggs and larvae. It may have a
greater or lesser effect on fruit physiology. If the treatment temperature and duration
are incorrectly handled, skin burns may result and the internal quality of the fruit may
be affected. Materials and methods. ’Cat Hoa loc’ mangoes at the commercially
mature stage were subjected to hot air treatment (47 °C and 90% RH) of different durations
[(0, 20, 40, 60, 90, 120 and 180) min from the fruit core attaining the temperature].
After treatment, the fruits were stored at 25 °C and quality parameters evaluated (weight
loss, peel and flesh colour, percentages of fruit with burns and rots, burn index,
ripening percentage, firmness, TSS, TA, vitamin C content, pH, reducing and total sugars,
and taste test). Results and discussion. For the ‘cat Hoa loc’
variety, heat treatment accelerated ripening of the fruit in the initial storage period
and colour changes occurred more quickly. However, after 7 days' storage, the difference
in Hue value between the treated and control fruits disappeared. Hot air treatment at
47 °C of different durations [(20 to180) min] did not affect the internal coloration
changes of ‘cat Hoa loc’ mangoes, but did affect the flesh firmness. We found that, after
3 d, hot air treatment at 47 °C led to significantly faster weight loss than control
fruits but this difference disappeared after 7 d. Total sugar content was not affected by
the treatment, but titratable acidity decreased more quickly in treated fruits.