FOOD VALUE OF SEA MUSSELS. 
105 
COMPOSITION AND NUTRITIVE VALUE. 
The function of food is to build up new tissues and repair them as they are worn 
out by use, to supply heat energy for keeping the body warm and muscular energy for 
doing work. The nutritive value or degree to which a food material is able to perform 
this function depends upon two factors, (1) the ratio of edible portion to refuse and (2) 
the relative amounts of nutrients contained in the edible portion. The first of these is 
determined by separating the flesh and liquor from the shells and byssus of the mussels, 
then weighing them separately and determining the percentage of each present. The 
second factor is determined by means of a chemical analysis of the edible portion. 
The nutrients sought represent four classes of compounds: (1) Protein, which forms 
the nitrogenous basis of blood, muscle, connective tissue, etc.; (2) carbohydrates; (3) 
fats, which may be stored up as fat or consumed for fuel; and (4) mineral matters or 
ash, which are used chiefly in the formation of bone. 
In studying the ratio of edible portion to refuse two sets of determinations were 
made. One was based on the examination of fresh or uncooked specimens and the 
other on mussels which had been cooked by steam. In the first case the mussels were 
weighed after being washed free from dirt. They were then quickly shucked and 
“bearded,” the meats and liquor being preserved in separate dishes. What liquor 
adhered to the flesh was drained off and added to the other dish. The weights of the 
flesh and liquor werp ascertained and recorded. The total weight of the mussels minus 
the combined weights of the flesh and liquor was considered the amount of refuse 
matter. This method, it will be observed, places the loss due to handling in the refuse 
column. The results obtained from the examination of five separate lots of mussels will 
be found in the following table : 
Table 3 . — Showing Proportion of Edible Parts to Refuse in the Sea Mussel. 
Determinations from fresh or uncooked material. 
Date. 
Num- 
ber 
taken. 
Total 
weight. 
Aver- 
age 
weight. 
Flesh. 
Liquids. 
Total 
edible 
portion. 
Refuse. 
Flesh. 
Liquids. 
To + al 
edible 
portion. 
Refuse. 
1908. 
Lbs. 
oz. 
Ounces. 
Lbs. oz. 
Lbs. oz. 
Lbs. 
OZ. 
Lbs. 
oz. 
Per ct. 
Per ct. 
Per ct. 
Per ct. 
July 10 
50 
5 
4 
1. 68 
1 8i 
1 6| 
2 
1 44 
2 
5 4 
28. 87 
26. 78 
55-65 
44 - 35 
July 13 
100 
9 
13 
i -57 
2 13J 
2 8 
5 
5 s 
4 
7s 
28. 75 
25. 48 
54 - 23 
45 - 77 
August 8 
5 ° 
4 
52 
i -39 
I IlV 
i h 
2 
if^ 
2 
3 if 
25-35 
23 - 74 
49 - 09 
50 . 91 
August 26 
20 
2 
3 4 
1.76 
O 9 T 8 
0 io* 
I 
3 s 
0 
26 . IO 
29. 00 
55 - 10 
44 - 90 
August 28 
1 1 
I 
if 
1. 68 
0 5 b 
0 4 b 
O 
9 b 
0 
7 f 
30. 80 
25 . 00 
55- 80 
44 - 20 
Total 
231 
22 
Ilf 
i- 57 
6 5 
5 13! 
I 2 
2§ 
10 
8! 
27. 79 
25- 75 
53 - 54 
46 46 
In the second case the total weight, as above, was taken after washing the mussels 
free from dirt, but before removing the meats and liquor the shellfish were cooked by 
means of steam until the shells began to open. This treatment gives very different 
results from those obtained from the raw material, as may be seen in the following: 
