No abstract

The explosion-puffing process produces excellent dehydrated apple products that can be used as crisp snacks, instant applesauce, and ingredients for pies, tarts, and cobblers. To make these products more competitive and facilitate commercialization of the process, a continuous explosion-puffing system (CEPS) has been developed. The CEPS process has been optimized for orchard run Rome Beauty apples. Leaching loss as well as SO, absorbance and processing losses were determined. Drying profiles from a continuous belt drier were made. Pressure, temperature, and feed moisture were used as control variables for CEPS optimization studies. Analytical tests for bulk density, rehydration, color differences, percent disintegration, and hydroxymethylfurfural were performed on each sample. From these responses a bias was discovered, necessitating a second study. The second optimization study of these responses produced an optimal region. Any point in this region gives a value of pressure, temperature, and moisture. When these conditions are used for CEPS an excellent apple product results. Orchard run Winesap apples were processed through CEPS at an optimal condition determined for Rome Beauty apples to evaluate varietal differences. While their response was significantly different, the product was acceptable.

Nutritive losses of hot water blanched potatoes were studied. The potatoes lost significant amounts of some amino acids-glutamic acid, aspartic acid, valine, phenylalanine, arginine, methionine and tryptophan. They also lost a significant amount of gamma-amino butyric acid. The concentration of the water soluble vitamins, ascorbic acid, riboflavin, thiamin, and niacin was significantly reduced. A leaching model, with diffusion as the rate controlling step, successfully predicted losses of these vitamins as a function of process parameters.

Processing potatoes to potato flakes almost totally eradicated ascorbic acid, but better than 50% of the original amount of riboflavin and niacin was retained. Thiamin content of potato flakes can vary from &65% of its amount in the raw potato depending on the amount of sulfite added during processing. If sulfite addition is controlled, a 1OOg portion of rehydrated potato flakes can supply about l/6 of the Recommended Dietary Allowance of thiamin. Some losses of arginine, aspartic acid, glutamic acid, and gamma aminobutyric acid occurred during hot water blanching, and a significant loss of methionine occurred during drum drying. However, amino acids can be considered quite stable during potato flake production.