Origins and Development of USDA Standard Reference 28
The USDA National Nutrient Database for Standard Reference (SR) was a primary source for food composition data in the United States, with SR28 being its final iteration. The database's history traces back to a compilation of earlier publications, including the extensive Agriculture Handbook 8 series. Over the decades, the USDA Nutrient Data Laboratory continuously updated and expanded the dataset, making the information available electronically. SR28 was released in September 2015, with a final revision in May 2016, marking the end of the long-standing 'SR' series.
The development process for each release involved compiling data from multiple sources. The USDA Agricultural Research Service (ARS) drew information from published scientific literature, unpublished industry data, and government research. This meticulous process ensured the database was as comprehensive and accurate as possible for its time.
Core Features and Data Structure of SR28
SR28 contained data for 8,789 food items and up to 150 food components. The information was structured in a relational database format, typically accessible in formats such as Microsoft Access and ASCII delimited files.
Key Data Components in SR28
- Food Descriptions: Detailed records for each food item, including raw, processed, and prepared versions.
- Nutrient Data: Mean nutrient values per 100 grams of the edible portion of each food.
- Weights and Measures: Information correlating household measures (e.g., cups, teaspoons) with their corresponding gram weights.
- Footnotes: Additional descriptive information or details about certain food items or nutrient values.
One of the notable aspects of SR28 was the availability of both a comprehensive and an abbreviated version. The abbreviated file was smaller and omitted less-common nutrients, making it easier for basic nutritional analysis applications.
Practical Applications of SR28
For years, SR28 served as a vital tool for various professional and academic fields. Its applications included:
- Dietary Planning: Dietitians and nutritionists used the data to create and assess patient meal plans.
- Nutritional Research: Scientists relied on the database for conducting nutritional studies and epidemiological research.
- Food Product Development: Food manufacturers utilized the data to formulate new products and ensure they met specific nutritional criteria.
- Regulatory Compliance: The data was foundational for generating the nutrition facts labels required on food packaging by the FDA.
The Evolution from SR28 to FoodData Central
In April 2019, the USDA integrated the data from SR28 and other nutrient datasets into a new, more comprehensive platform called FoodData Central. This move addressed some of the complexities and limitations of the legacy SR database format. For instance, the SR database was not fully normalized, and its structure could be challenging to navigate, as noted by developers who worked with it.
The transition to FoodData Central was a significant upgrade, consolidating multiple data types into a single, unified system. While SR28 and its predecessors focused primarily on nutrient composition, FoodData Central expanded to include five distinct data types, offering a more holistic view of food information.
SR28 vs. FoodData Central
| Feature | USDA Standard Reference 28 (SR28) | USDA FoodData Central |
|---|---|---|
| Final Release | May 2016 | Ongoing |
| System Status | Legacy, replaced by FoodData Central | Current, active system |
| Data Sources | Primarily analytical values compiled by USDA | Multiple data types, including SR Legacy, Foundation, and Branded Food data |
| Data Scope | 8,789 food items and up to 150 components | Significantly broader, encompassing SR Legacy plus new branded, survey, and research data |
| Database Structure | Relational format, sometimes complex | Unified, modern data system |
| Accessibility | Previously available via USDA website downloads | Available through the centralized FoodData Central website |
Conclusion
The USDA Standard Reference 28 played a critical and long-standing role as the authoritative source for food composition data in the United States. From its release in 2015 to its retirement in 2019, it was indispensable for dietitians, researchers, and food manufacturers, enabling consistent and reliable nutritional analysis. The legacy of SR28 continues within the modern FoodData Central system, which has built upon its foundational data while expanding its scope and usability. For anyone conducting nutritional research or food-related analysis today, understanding SR28 is essential context for the data now found in FoodData Central.
Further Reading
For more information on the history and specifics of the Standard Reference database series, including SR28, visit the official page on the USDA website: USDA Legacy Standard Reference Data
