Hence there has been no dilution of the TBA reacting substances and as
a result there is a gradual increase on storage.
Texture of the raw clam and cooked clam after thermal
processing was determined using a food texture analyzer.
Different parameters like hardness 1, hardness 2, springiness,
cohesiveness, chewiness were studied. Triplicate samples
analyzed and average values were taken for
presentation of data (Fig. 5). It is seen from the figure that
there has been a decrease in hardness 1 from 2.07 kgf to
1.93 kgf and from 1.67 kgf to 1.66 kgf in hardness 2 of
the raw clam meat when thermal processing was done.
The change in the hardness is mainly due to heat processing
which causes conversion of collagen to gelatin and dissociation
of muscle protein. Cohesiveness is an indication of
the internal bonding of the clam muscle. Because of the
heat processing a breakage in the water bond occurs.
Hence there is a decrease in the value from 0.39 to 0.32
when compared to the raw clam meat. Springiness is the
elastic recovery property of the clam meat. It is expressed
in terms of mm. In the raw condition the product is more
elastic in nature, but on heat processing the elasticity is
lost. Hence there is a decrease in these values from 0.67
to 0.59 mm. Chewiness refers to the work done. In any
raw product the work done is more whereas in the thermal
processed products the work done is less. The value of
chewiness in raw clam meat was 0.54 kgf mm and in thermal
processed it is 0.36 kgf mm.
Overall acceptability was determined using 10-point
hedonic scale and scores below 4 was taken as the unacceptable
limit for the rejection of the samples. Flavour
score decreased from 8.5 to 6.5, with respect to texture it
decreases from 8.5 to 7. The details are given in Table 5.