Kishk - a dried fermented milk / cereal mixture. 1 Composition of gross components, carbohydrates, organic acids and fatty acids

Abstract

An investigation of the compositional quality of 25 commercial samples of Lebanese Kishk was undertaken. The results of chemical analysis (g.100 g-1 on dry matter basis [DMB]) of the samples were within the following ranges: protein, 14.7-21.4; fat, 2.6-11.5; ash, 4.1-9.3; and carbohydrates, 61.0-76.8. The moisture and salt contents ranged between 6.8 and 10.8. and 0.95 and 4.48 g.100 g-1, respectively, and the pH averaged 3.8. The carbohydrate content calculated by difference (total solids - [protein + fat + ash]) was slightly greater than by the summation method (galactose + lactose + fibre + starch). Lactic and acetic acids were identified to be the major organic acids present in the Kishk samples, including an appreciable amount of propionic acid. Principal component analysis (PCA) was used to map the relationships between these samples; PC 1 of the organic acid data accounted for only 37% of the total variation separating the Kishk samples high in propionic, lactic and uric/formic acids, and those with high acetic, orotic, pyruvic and citric acid contents. Profiling the fatly acid content in the Kishk samples did not conclusively identify the type of milk used, but the ratios of C4:0/(C6:0 + C8:0) and C12:0/C10:0 provided appropriate mapping of Kishk samples made with goat's milk and possibly adulteration with cow's milk at a level of 20 %. © Inra/Elsevier, Paris.