2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center

The occurrence of syneresis in gelatinized starches has important technological implications. On the other hand, formation of resistant starch is greatly relevant from the nutritional point of view. However, the possible relationship between these two retrogradation-associated phenomena has not been evaluated so far. This problem was addressed in the present investigation. Isolated starches from three cereals (corn, rice and sorghum), two legumes (jack bean and lentil) and arracacha roots (Arracacia xanthorrhiza) were gelatinized by boiling for 30 min. Drained gels were stored for 24 h at 4°C and analyzed for syneresis index and retrograded resistant starch (RS-3) content, using widely accepted methods. Legume starches reached 6-7% (dmb) RS-3 levels, while the lowest values (2-3.6%) were recorded for corn, rice and arracacha samples. Jack bean starch gels showed the greatest water exclusion index, followed by the cereals, arracacha and lentil preparations. Neither syneresis indices nor apparent amylose contents showed clear correlation with RS-3 levels in the stored gels. It is therefore suggested that different mechanisms govern water separation and RS-3 formation in gelatinized starches, which adds to the complexity of starch retrogradation.