EFFECT OF PROCESSING ON SOME CHEMICAL CONSTITUENTS OF PISTACHIO NUTS

Abstract

The effect of processing on changes in fatty acids, sugars and amino acids in pistaschio nuts during blanching, drying and roasting was monitored. Blanching in hot water led to some loss in fatty acids, sugars and amino acids. Roasting further decreased the availability of the constituents. The magnitude of loss of the constituents was in the following order: blanching > roasting > drying. The composition profile of each of the constituents was analyzed. There was variation in the distribution of fatty acids among the raw and processed nuts. Unsaturated fatty acids were more susceptible to changes during processing. The combined loss of oleic and linoleic acids amounted to 22.29% of that present in the raw nuts. Fructose, glucose, sucrose and raffinose were shown to be present in the nuts. The loss of sucrose was higher than the monosaccharides during processing. Glutamic acid, leucine, proline 56.50% of the amino acids present, and blanching, drying and roasting successively caused losses in the availability of these amino acids. The effect of processing on nutritional values has been a subject of concern to consumers and food processors. The present investigation reveals that the loss in various components in the nuts deserves more attention. Copyright © 1982, Wiley Blackwell. All rights reserved