In vitro and in vivo digestibility of native maize starch granules varying in amylose contents.

Digestibility of maize starch granules with different amylose content (AL-0, 22, 54, 68, 80, or 90%) was investigated. Measurement of the in vivo resistant starch (RS) content of the starches was performed using surgically prepared ileorectostomized rats. The rats were fed a purified diet containing one of the starches at 652.5 g/kg diet. The in vivo RS content was determined based on the fecal starch excretion. The dietary fiber (DF) value increased as a function of the amylose content in the starch and showed a positive linear correlation with the gelatinization temperature of the granules. In contrast, the in vitro RS content was likely to depend on both the surface area and amylose contents of the starch granules. The maximum in vitro RS content was obtained with AL-68 (54.4%). In vivo RS content showed a significant correlation with the amount of in vitro RS but not in respect to the DF detected. The in vivo RS content of AL-68 (43.4%) was higher than that found in AL-90 (37.8%). A profound gap was observed for AL-54 between the amount of DF (6.4%) and RS (in vitro = 46.6% and in vivo = 40.9%) present. The results suggest that both in vitro and in vivo digestibility of maize starch is affected by the amylose content and surface area of the granules. The current evaluation suggests that the physiological occurrence of RS from maize starch might be predictable by reference to the in vitro RS value.

Central administration of cocaine- and amphetamine-regulated transcript inhibits food intake in chicks.

The present study was done to clarify whether intracerebroventricular (ICV) injection of cocaine- and amphetamine-regulated transcript (CART) affects feeding in chicks. ICV injection of CART significantly inhibited fasting-induced feeding of broiler chicks. In layer chicks, on the other hand, CART inhibited food intake in birds with ad libitum access to feed but only weakly affected intake of fasted birds. In addition, the ICV injection of CART attenuated neuropeptide Y (NPY)-induced feeding in both broiler and layer chicks. These results indicate that CART is one of the important regulators of feeding in chicks, but the suppressive effect on feeding is somewhat different between strains. Furthermore, the present study also demonstrates that CART interacts with NPY in the central nervous system to regulate feeding in chicks.