Vitamin C Fortification of Food Aid Commodities: Final Report (1997)

As directed by Congress, the U.S. Agency for International Development (USAID) developed and implemented a pilot program to produce and provide blended food aid commodities with enhanced levels of vitamin C fortification to at least two field sites. USAID implemented a cooperative agreement with the organization SUSTAIN (Sharing United States Technology to Aid in the Improvement of Nutrition) to implement the pilot program so that it would represent closely ordinary food aid operations from procurement through distribution at field sites. SUSTAIN's primary responsibilities included (1) monitoring and statistically analyzing the variability in vitamin C content of fortified blends at the manufacturing site and estimating the production costs; (2) monitoring vitamin C losses during shipping, storage, and distribution; (3) estimating vitamin C losses during food preparation; and (4) collecting dietary information to estimate the contribution of the commodity to the recipients' total daily vitamin C intake. This chapter summarizes the pilot program implemented by SUSTAIN and outlines its major findings.

SUSTAIN developed two vitamin premixes. One provided the standard level of vitamin C fortification of 40 mg/100 g of dry blended cereal when added at the rate of 908 g per metric ton (MT). The other premix provided vitamin C fortification at the level of 90 mg/100 g of dry blended cereals when added at the rate of 1,363 g/MT. Contracts for production of the pilot procurements were awarded to the lowest bidder using standard USDA-CCC (U.S. Department of Agriculture, Commodity Credit Corporation) procurement procedures. Two production plants were selected to prepare the fortified cereals:

plant A produced 500 MT of corn-soy blend (CSB) with high vitamin C and 500 MT of CSB with conventional levels of vitamin C; and plant B made 240 MT of conventionally fortified wheat-soy blend (WSB) followed by 240 MT of WSB with high vitamin C. Special markings were printed on the bags of these pilot production runs to facilitate finding the bags for sampling when they reached their distribution locations.

Countries chosen by the USAID's Office of Food for Peace and SUSTAIN for the pilot program were Haiti for WSB, a regular development type of food aid program and Tanzania for CSB, an emergency feeding situation. The primary criteria for site selection were that at least one country food aid program had to be chosen where scurvy had been reported in past camp feeding situations and one program where significant iron deficiency has been reported. Although there have been no reports of scurvy emanating from Tanzania to date, its location in the greater Horn of Africa where numerous cases of scurvy have been reported and the emergency feeding situation in the camps there indicated a very high risk situation.

Based on recommendations from the statistical subgroup of SUSTAIN's advisory panel, 48 samples of each run were collected. Sample collection was spread evenly over a two-to three-day run time. Ten of these samples were duplicated for use as blind analytical checks. A SUSTAIN representative, with the assistance of the USDA Feed Grain Inspection Service (FGIS) inspector and plant Quality Control (QC) staff, collected samples from each production run. Determination of whether a pilot production run was worthy of continued study was based on the following criteria: (1) the production was within control limits by normal standards of statistical quality control as applied by the U.S. food industry and (2) the variance in production was small enough to detect a 20 percent drop in ascorbic acid content at a 95 percent confidence level.

After initial results indicated uniformity problems in the fortification of CSB, USAID and the SUSTAIN Vitamin C Advisory Panel agreed that each of the seven plants that had been awarded CSB and WSB production contracts should be sampled to assess the extent of the problem. Five of the seven plants were sampled; 4 of the 5 CSB manufacturing plants and one of the two WSB manufacturing plants. The remaining two plants were not in production during the sampling period. Because the vitamin C content of the special CSB produced in plant A did not meet its criteria of acceptability for further study, SUSTAIN planned to postpone field testing of CSB in Tanzania indefinitely. However, in its preliminary report on the pilot program (IOM, 1996), the Institute of Medicine Committee on International Nutrition recommended to SUSTAIN that retrieval and analysis of samples of CSB delivered to Tanzania would be of value for two reasons: (1) to determine if vitamin C remained in the

samples even though the mean concentration could not be specified precisely and (2) to provide information on the mean vitamin C content and its variability in field samples that would be needed to examine cost-effectiveness. In this situation, locating the coded bags to obtain paired samples for analysis would be more critical.

Because of concern over the variability in vitamin C content of CSB shipped to Tanzania, another production lot of CSB, which had been shipped to India from a plant that met SUSTAIN's criteria for uniformity, was identified for field testing of cooking losses. This material contained only the standard level of 40 mg of vitamin C per 100 g of dry commodity.

The stability of vitamin C was to be assessed by the following independent methods:

• Analysis of mean levels and variation of vitamin C content at production of the CSB and WSB compared to the same lot of product just prior to food preparation in the recipient country.
• Analysis of paired samples of specially marked bags: Once the specially marked sampled bags were located in the field and sampled, their vitamin C content was compared to the vitamin C content found in the same bags during production.
• Using niacin as a marker of vitamin fortification: Niacin, which is included in the vitamin premix for fortification of CSB and WSB, is considered a highly stable vitamin and is not likely to show a decrease during storage and transport. Since the vitamin premix has a uniform ratio of niacin to vitamin C, a change in this ratio would reflect a loss of vitamin C. Because of a number of limitations associated with this method, it was intended to be used only if the other two methods failed due to inadequate data. Ultimately, it was not used as a measure of vitamin C retention.

Time intervals from production to distribution site samplings represented transport and storage time and were seven months for CSB sampled in Tanzania, nine months for WSB sampled in Haiti (Box 4-1 and 4-2), and five months for CSB sampled in India.

Food preparation studies were conducted in both Haiti and Tanzania. The purpose of data collection on food preparation was to determine the extent to which vitamin C is lost as a result of typical preparation techniques. Objectives were (1) to document the food preparation methods used by beneficiaries of food aid in two feeding programs and (2) to sample prepared foods from several beneficiary households for vitamin C analysis. Preliminary observations had shown that in Haiti the most commonly prepared WSB dishes were gruel, and dumplings cooked in a vegetable broth. In the Tanzanian refugee camps the most commonly prepared CSB dishes were gruel and ugali (a Swahili word referring to a stiff porridge traditionally prepared with fermented cassava). Gruel was the most commonly prepared food for both CSB and WSB, accounting for 24 out of 39 samples. Details of the complete methodology used can be found in Ranum and Chomé (1997) and cooking loss data are summarized in Table 4-1.

• Uniformity of vitamin C in commodities at manufacturing site. Following the initial sampling of CSB, which indicated poor uniformity of product, the consensus was that each of the seven CSB and WSB plants that were awarded production contracts should be sampled. Five of seven plants were sampled, and results indicated that only two of the five plants—one batch processor and one continuous processor—met contract specifications most of the time (>90 percent). Two of the other plants (both utilizing a continuous process) were outside specifications more than 50 percent of the time.

• Stability of vitamin C from manufacture to points of distribution. The vitamin C stability component of the study did not include data from Tanzania because the CSB pilot production sent to Tanzania was not sufficiently uniform to allow for efficient testing. The WSB sent to Haiti with conventional levels of added vitamin C showed a small but statistically significant loss of 13 percent. The WSB sent to Haiti with the high level of vitamin C, and the CSB shipped to India with conventional levels of vitamin C both showed essentially 100 percent retention of added vitamin C. Results from comparison of mean levels and comparison of paired samples in specially marked bags were very similar.
• Vitamin C retention during food preparation. Results from these studies showed large losses of vitamin C in both CSB and WSB in prepared food made from these commodities (Tables 4-2 and 4-3). The magnitude of this loss for CSB was inversely proportional to concentration: the higher the level of the vitamin in the dry commodity before cooking, the greater was the retention. Retention of the conventional level of added vitamin C was 17–32 percent in CSB and 27 percent for WSB gruel samples. At the high level of added vitamin C, the retention was 44–74 percent for CSB and an average of 32 percent for WSB. Five out of nine gruel samples, made from CSB with the conventional level of vitamin C, showed vitamin C content to be below the level of detection of 1 mg/100 g.
• Analysis of vitamin C cost. The best cost estimate of adding vitamin C to CSB and WSB manufacturer, if the proposed change were instituted today, is $6.33/MT. Based on Fiscal Year 1996 purchases, this would have meant spending an additional $1,580,000 per year. It is important to note that the price of ethyl cellulose-coated vitamin C varies depending primarily on the price of ascorbic acid. The current base price of ascorbic acid is at an all time low, $5–$7/kg in 1997 (Ranum and Chomé, 1997). In 1995 the actual prices paid for ascorbic acid by a large vitamin premix manufacturer ranged from $13.40 to $15.75/kg.