Introduction to Human Nutrition

288 Introduction to Human Nutrition

● Compare the moisture content of the calculated
recipe with a similar cooked composite dish. If the
moisture content differs by more than 1%, adjust
the moisture content of the recipe food. All of
the nutrients of the recipe food must be adjusted
(concentrated or diluted) according to either the
decrease or increase in moisture content.
● Assign to a suitable food group and list.

This is only an estimation of the make-up of a com-
posite or mixed dish of unknown composition. Refer
to Table 11.7 for an example of the calculation of the
composition of a dish from a recipe. However, if this
dish is a very important part of the diet of an indi-
vidual or group and the information is crucial in
assessing the adequacy of the diet, analysis should be
considered.

Accurate estimation of portion size

Food composition tables and databases are mainly
used in nutritional epidemiology to estimate the
composition of foods consumed by individuals. All
subjects have diffi culties in estimating the exact
portion sizes of food consumed. This issue is further
complicated by the difference between the weight of
a product as purchased and that of the actual item
consumed (e.g., in meat after cooking there is at least
a 25% cooking loss, without bone and with or without
visible fat). Standardized portion sizes for individual
foods within countries may help, but a set of standard
food models (small, medium, and large) for use in
dietary assessment may be of more value.

11.6 Description of food composition
tables and databases and how to
retrieve data

A food composition table or database is easier to use
if the format allows easy access to the data available.
Advances in information technology have led to more
and more food composition tables being available in
electronic form, progressively replacing the printed
format. Printed food composition tables, although
limited by physical proportions such as the size of
both the written text and the printed table, continue
to be popular in developing and underdeveloped
countries. The printed word is seen as authoritative
and only a limited level of literacy or knowledge on
nutrition is necessary to be able to access the data.

Electronic data and access to them are more limited

in remote areas in these countries, and a higher level

of computer literacy and equipment is necessary,

which is generally seen as a luxury and not a

necessity.

However, electronic databases have many advan-

tages over printed tables, including virtually unlim-

ited capacity to store information, rapid access to

Table 11.7 Calculation of the composition of a dish from a recipe

Recipe for scrambled eggs with onions

2 large eggs

(^1) / 6 cup whole milk
(^1) / 8 teaspoon salt
(^1) / 4 cup chopped raw onions
2 teaspoons oil
Add milk and salt to eggs and beat with a fork. Fry onions in the
oil. Pour egg mixture into frying pan with the onions, and stir
mixture with a fork while cooking until it solidifi es. Makes one
serving.
Calculation of nutrient content of scrambled eggs from nutrient
values for raw ingredients
Step 1:Add nutrient levels for the specifi ed quantities of ingredients
The nutrients in the raw eggs, whole milk, salt, raw onions
and oil are added together
Step 2:Readjust quantities of those nutrients in the raw ingredients
that are lost during cooking due to evaporation or heat
Nutrient loss on cooking Eggs Milk Onions
Thiamin (%) 15 10 15
Ribofl avin (%) 5
Niacin (%) 5
Ascorbic acid (%) 25 20
Folacin (%) 30
Step 3:Determine weight of the recipe before cooking
1 large egg = 57 g; 57 g × 2 eggs = 114 g; refuse factor to
calculate weight without shell of 11%;
1 14 g × 0.89 = 101.46 g
1 cup whole milk = 244 g × 1 / 6 = 40.66 g
1 teaspoon salt = 5.5 g × 1 / 8 = 0.69 g
1 cup chopped raw onions = 170 g × 0.25 = 42.5 g
1 teaspoon oil = 4.53 g × 2 = 9.06 g
Total weight = 194.37 g
Step 4:Determine weight of recipe after cooking
Weight loss during cooking due to evaporation is estimated
to be 8%
Weight of recipe after cooking = 194.37 g × 0.92 = 179 g
Step 5:Determine the nutrient levels of the recipe per 100 g and
per serving
Divide the nutrient levels by 1.79 to determine the nutrient
content of 100 g scrambled eggs
The calculated nutrient levels represent the nutrient content
of one serving