4. Conclusion
This paper has studied some pre-treatment and dehydration
approaches to develop a process of making Gac powder
from the fruit flesh. Between two enzymes used in the
pre-treatment, Maxoliva had a stronger performance than
Pectinex to degrade the Gac arils, in 4 h at 35 C. This
could be applied in the mass production of the Gac powder
because the seeds could be scraped out of the homogeneous
paste in a continuos process. Furthermore, using the same
oven drying method, the constant drying rate of the arils
with the enzymatic treatment were greater than without
treatment but the total drying time of different samples
from different drying methods: oven, vacuum and air types
varied from 14 to 18 h. Amongst five different drying methods,
freeze-drying of the whole-seed flesh produced the Gac
powder with the highest carotenoid content and brightest
colour but this advanced technique was not cost effective
compared to oven and air drying. The average loss of
carotenoids of five powder samples after pre-treatment
and using oven and air dryers was 35%. Gac powder stored
in vacuo below 25 C retained the good quality over 4
months and was found to be acceptable in some trial food
products. Further research is recommended into the drying
processes and packaging to improve the shelf-life and quality
characteristics of the product.