Abstract:
The main approach of this study was to evaluate the effects of freezing and thawing
process on the physical properties and acceptability of tempeh fish ball. Five
formulations of tempeh fish ball were developed. These formulations were the
incorporation of tempeh in the ingredients at 0%, 5%, 10%, 15% and 20%. Physical
analyses were carried out for five freeze-thaw cycles (FTO, FTl, FT2, FT3 and FT4)
at every week within 28 days of storage. Tempeh fish balls were analyzed for physical
characteristics including color (whiteness index), texture (hardness, chewiness,
springiness, and gumminess) and folding test for every freeze thaw cycle. Whereas,
only fresh sample (FTO) were analyzed for chemical properties (moisture content,
protein, fat, ash, carbohydrate and crude fiber). The chemical composition of tempeh
fish balls were ranged from 74.55 to 77.22% of moisture content, 10.78% to 12.43%
of protein, 0.55% to 1.07% of fat, 9.13% to 10.51% of carbohydrate, 1.36% to 1.65%
of ash and 0.09% to 0.67% of crude fiber content. Increment of the percentage of
tempeh incorporation, increased the composition of moisture, ash and crude fiber of
the fish ball. On the other hand, the protein, fat and carbohydrate were reduced
significantly (p:::0.05). Most of the physical characteristics showed reduction in their
values with the increased of tempeh incorporation as well as through freeze-thaw
cycles. Microscopic structure showed that freezing and thawing enlarged pore sizes
and changed the structure of tempeh fish ball. For the sensory evaluation, the
consumer acceptance level of tempeh fish ball were significantly decreased when the
percentage of tempeh in the formulations increased as well as when the freeze-thaw
cycle increased. Most of the attributes showed the decreasing of acceptability values
with the increasing of tempeh incorporation, especially formulation E (20% tempeh).
All formulations also showed the reduction of acceptance level after three freeze thaw
cycles. Formulations B (5% tempeh) was selected as the most accepted tempeh fish
ball as it showed similar acceptance score values with the control (0% tempeh) for the
most attributes evaluated.
