Accelerated Shelf Life Studies: Testing Micronutrient Stability of New and Upgraded Food Aid Products
Authors: Schlossman Nina , Johnson Quentin , Wood Lauren , Coglianese Nicole , Santoso Vicky , Koeppel Leah 
Published: June 2021

Accelerated shelf life and stability studies are a critical part of product research and development (R&D) and are being included as new and upgraded food aid products are introduced. The aim here was to determine the vitamin and mineral stability and integrity of United States products included in the Food Aid Quality Review (FAQR) Phase II food aid effectiveness trials. Tests were carried out on Corn‐Soy Whey Blend (CSWB), Super Cereal Plus (SC Plus), Corn Soy Blend Plus (CSBP), Ready‐to‐Use Supplementary Food (RUSF) and Fortified Vegetable Oil. The samples were analyzed for vitamin content (vitamins A and C), mineral content (iron, calcium and phosphorus), peroxide levels and organoleptic properties (appearance, odor, taste, packaging appearance). Testing followed standard methods certified by the Association of Official Analytical Chemists (now AOAC International) and commonly used by the food industry and the United States Department of Agriculture (USDA) Official Testing laboratories. All products were stored at 40 degrees Centigrade (104 degrees Fahrenheit) and 75 percent relative humidity for a period of 26 weeks to mimic 26 months in real time. The products were sampled and tested seven times.

Vitamin A levels in all fortified blended foods (FBFs) degraded substantially during testing but remained very stable in RUSF and fortified vegetable oil, both lipid‐based products. Peroxide levels remained below the maximum permitted in the FBFs compared to specifications, but reached and exceeded the maximum permitted in vegetable oil by week six (equivalent to six months storage). Organoleptic characteristics: FBFs all developed a slight grainy odor over the course of their shelf lives. Three of the four showed sparse black flecks at various points that were likely due to dark germ color and heat processing of the raw material (corn). RUSF odor, appearance, texture and packaging remained stable and normal. Appearance, taste and packaging characteristics of fortified vegetable oil remained unchanged despite an increase in peroxide values during the shelf life study period; a slight “oily” odor was detected only at week six. Mineral levels varied among the FBFs, mostly as expected, due partially to intrinsic differences in product ingredients. These findings highlight the role that that intrinsic values play in establishing specifications. Vitamin C (endline only) levels were uniformly low in all FBFs but within the normal range in the RUSF.

The use of new types of ingredients and modifications in micronutrient levels, types and forms (vitamins and minerals) can have an impact on both shelf life duration and organoleptic properties of FBFs through the supply chain. Accelerated shelf life studies are industry standard for new product development and should be adopted as due diligence and become standard for all new or upgraded food aid products. Shelf life protocols and conditions should be harmonized among aid organizations working on product development for comparable data and results. Further research is needed to optimize vitamin A delivery in the USAID food aid basket, including improving vitamin A stability in dry premixes for inclusion in FBF production and determining the most appropriate delivery mechanism. Packaging material innovation is required to reduce degradation of vitamin A and other vitamins.

Support or Funding Information

This research was funded by the United States Agency for International Development's (USAID) Office of Food for Peace (FFP) under USAID Contract AFP‐C‐00‐09‐00016‐00 with the Friedman School of Nutrition Science and Policy for Phase II of the Food Aid Quality Review (FAQR). The studies were conducted by Global Food & Nutrition Inc. and Covance Laboratories.