| Food Composition Data: A User's Perspective (1987) |
|Managing food composition data|
|Concerns of users of nutrient data bases|
As indicated above, many nutrient data-base users estimate nutrient profiles for mixed dishes based on institutional or family recipes. Estimates for some nutrients for recipes are included in many cookbooks. Both food-service management systems and nutrient analysis systems are being designed to facilitate the calculation process. To focus attention on some problems associated with this practice of nutrient estimation, Hoover and Perloff  included a simple recipe for a tuna noodle casserole as a computational task in a methodology for assessing computer software.
Several methods are being used to estimate nutrient profiles for recipes, with each requiring associated data not usually present in nutrient data bases. In USDA Handbook No. 8 , nutrient-retention factors, ingredient-weight adjustment factors, and nutrient profiles for raw ingredients have been used to calculate nutrients for recipes. Additional information about ingredient yields has been provided by USDA in another publication, Handbook No. 102 . Although provisional nutrient retention information has been made available , more information is needed for more foods and preparation methods.
In the 1960s, a different calculation method was implemented in food-service software systems [2, 3]. The major difference in calculation method was use of nutrient profiles for the finished form of each ingredient rather than the nutrient profiles for raw ingredients and nutrientretention factors. Numerous software systems are now using this yield-factor method.
Marsh  has described a study that focuses attention on the calculation of nutrients for mixed dishes. An approach for calculating nutrients based on "dish retention" was compared with the two methods mentioned above. Although all three calculation methods were used in the study, none of the methods was identified as best in a preliminary discussion of the findings.
Although elaborate procedures can be used to estimate nutrient retention and ingredient yields in a finished product, the actual nutrient profile for a recipe is not known unless a laboratory analysis is performed. Constituent over- or underestimation could adversely impact dietary guidance or menu planning. Further information is needed to identify the best methodology for calculating nutrients for recipes. Without a standard methodology, the results from various nutrient-analysis systems are not likely to be comparable. Depending on the method identified as most reliable to support the calculation process, additional ingredient information will be required. Some of this ingredient information, such as yield factors, may be suitable for incorporation into nutrient data bases.