Investigating carotenoid loss after drying and storage of

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8. Study under controlled conditions
The whole chips sample (3316.6g) was divided into 8 and then into 5 = 40 subsamples:
90g each.
Sub-sample: 90g was divided into samples of about 15g
A B C D E Rest of
sub-sample
Figure 8-4: Schematical representation of sub-division of samples for
representative collection of sweet potato chip during storage under controlled
conditions
1 st collection (A): 3/16 of initial sub-sample (90g) ~ 17g
2 nd collection (B): 3/16 of sub-sample ~ 14g
3 rd collection (C): 1/4 of sub-sample ~ 15g
4 th collection (D): 3/8 of sub-sample ~ 17g
5 th collection (E) possibly: 1/2 of sub-sample ~ 14g
8.3.2 Assessment of the storage system
Suitable storage conditions (i.e. sample containers; controlled temperature/humidity) had
to be designed for this experiment. Saturated salts are a suitable way of maintaining
constant humidity. Kilner jars of 1.5L were used because they were small enough to fit
in the incubators (in comparison with desiccators). Height of the jar was no more than
1.5 times the width of saturation salt solution occupying the bottom of the jar. The
greatest ratio width/height is recommended to offer the largest free surface of the
saturated salt for reaching humidity equilibrium (OIML 1996).
An adapted device had also to be found to separate the saturated solution, which is
liquid, from the dried chip samples. In the first place, the dried sweet potato sample was
held above the salt in the jar by a plastic cup, copper gauze and cotton wool.
Unfortunately the cotton wool layer held some of the water and was not 100% efficient
at stopping chips from falling into the saturated salt solution. Another alternative to the
cotton wool was to use a cotton fabric bag containing the chips, which allowed easier
removal of the chips. Some modifications were made to the system because it was