The nutritional status of the population is one of the important factors determining the quality and productivity of the population, which in turn affects national productivity. In the long term, good nutritional status contributes to the intelligence and health of the population. Consequently, programmes directed at improving the nutritional status of the population will undoubtedly be a high priority in the national development scheme of any country, developed or developing. Food fortification, i.e., the addition of nutrients to specific foods based on the dietary habits and nutritional status of the target population, is one of the most popular nutritional interventions for improving the population's nutritional status. For food-fortification programmes to be successful, their technical aspects need to be carefully assessed. These include the nutritional justification for food fortification, the acceptability of the fortified food product to consumers (both cost and taste), and any technical or analytical limitation to compliance with food regulations and labeling requirements. Important technical aspects of developing effective food-fortification programmes are the choice of food carrier, nutrient interactions, bioavailability of nutrients, stability of nutrients added under anticipated conditions of storage and processing (food preparation at the household level), and safety. A good fortified product should not cause nutrition imbalance, and excessive intake of nutrients should not have adverse effects. To provide better information for the consumer, the concept of overage should be introduced. Overage is the use of kinetic data on nutrient stability to calculate the amount of added nutrient so that the anticipated level of the nutrient at the end of the product's shelf life is in accordance with the level indicated on the label.

Abstract. The purpose of this study was to investigate the influence of particle size on the chemical properties of yam flour in five cultivars, yellow/YY, orange/OY, light purple/LPY, purple/PY, and dark purple/DPY. With a mesh sieve, three flour fractions were separated according to particle size: small (128.6-139.7 µm), medium (228.7-257.9 µm), and large (475.4-596.3 µm). The content of moisture (6.81-11.26 %db) and lipids (4.48-9.85 %db) decreased with the increase of particle size, while proteins (4.48-9.85 %db) and carbohydrates (78.12-83.76 %db) were not influenced by particle size. Folin-Ciocalteu reagent and chlorogenic acid were used as standard to investigate the total phenolic compounds in the yam flour, and high-performance liquid chromatography (HPLC) was used to investigate the anthocyanin and carotene contents. It was found that there was no size influence on the content of phenolics (0.27-2.82 %db), anthocyanin (2.25-15.27 mg/100g db) in LPY, PY, DPY or carotene (23.75-132.12 mg/100g db) in YY, OY. The differences in chemical composition were due to differences in particle size and heat treatment, but may also have been caused by the different composition of the milling process.

Samples of wild rice (38-40% moisture, wet basis) were dried to 7-8% moisture using three different drying air temperatures and relative humidities, namely, 1 lO"C-63% relative humidity, 1 lO"C-6% relative humidity, and 6O"C-20% relative humidity. Samples were subsequently hulled immediately (hulled hot) or hulled after storing 24 hr at room temperature (hulled cold). Evaluations included determination of hulling efficiency, kernel hardness and degree of gelatinization. Hulling was most efficient when a high drying air temperature was used and when the kernels were hulled immediately after drying. Total yield was not affected by temperature gradient or moisture gradient which the wild rice kernels experienced during drying. Head yield was maximum when wild rice was dried under conditions of a high drying air temperature and low mositure gradient, and when it was hulled hot, immediately after drying. The kernel hardness test confirmed that kernels were harder when dried under high temperature, low moisture gradient conditions. Degree of gelatinization studies confirmed that about 90-95% of the starch in kernels dried under these conditions was gelatinized. The gelatinization of starch was influenced by both temperature and rate of drying. Susceptibility of kernels to cracking increased with increasing magnitude of moisture gradient within kernels. The best processing conditions for wild rice using criteria previously described consist of drying under high air temperature and a low moisture gradient, and hulling the kernels hot, immediately after drying.

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