Measurement of starch digestion of naturally ¹³C-enriched weaning foods, before and after partial digestion with amylase-rich flour, using a ¹³C breath test

Abstract

Malnutrition in infancy is a global problem which leads to retardation of childhood growth and development. There is a pressing need to improve weaning strategies for infants of the developing world. Traditional Gambian weaning foods are watery and of low energy density, but addition of energy in the form of fat and carbohydrate leads to thick, viscous gruels which are difficult to ingest. Partial digestion with amylase (EC 3.2.1.l)-rich flour reduces their viscosity while retaining their energy density. The aim of the present study was to measure the digestibility of a maize-based weaning food, before and after amylase digestion, in malnourished children using a 13C breath test. Ten children (aged 7-16 months; mean weight-for-age Z score -0.8) received isovolumetric and isoenergetic quantities of a maize-based weaning food naturally abundant with 13C. Breath samples were collected at intervals of 30 min for 5 h thereafter and 13C0, enrichment was measured by isotope-ratio mass spectrometry. Percentage dose of l3c recovered increased from a mean 13.7 (SD 37)% before, to 18.3 (SD 5.6)% after ingestion of amylase-treated weaning foods (P < 0.1). There was a significant inverse relation between age and weight, and percentage dose of 13C recovered in children receiving amylase-treated feeds. There were no differences in concentrations of amylase in saliva of infants or breast milk of their mothers. Partial digestion of supplementary foods may improve the nutrition of undernourished weaning children, not only by reducing their viscosity, thereby increasing ingestion, but also by improving their digestion and thereby their absorption.

Comparison of starch digestibility of a blended food prepared with and without extrusion cooking

“…For both ours, the peak of 13 CO 2 excretion occurring at 4 h, suggested a rapid digestion and probably the same gastric emptying for both meals. However, the similar starch digestibility of EF and NEF reported here may not be extrapolated to malnourished children, who often have an impaired starch digestion (Weaver et al, 1995).…”

Iron-Fortified Infant Cereals

“…(55,56) Infant cereals are traditionally treated with amylolytic enzymes prior to roller drying (drum drying) to enhance viscostability and to ensure that the prepared pap is energy dense and easy to digest. (40,54) Amylase treatment of cereal converts starch into maltose, glucose, maltotriose, other saccharides, and dextrin. (56,57) The carbohydrate in commercial infant cereals is digestible by infants as young as one-month-old.…”

“…(51)(52)(53) Cereal flour or meal is dispersed in water to form a slurry and amylolytic enzymes are added that hydrolyze a portion of the starch. (40,54) The slurry is then fully cooked to gelatinize the cereal starch and improve its digestibility, and the cooked slurry is dried using a drum-dryer, also referred to as a roller-dryer. The result is shelf-stable, instantly dispersible flakes that form a calorically dense pap upon addition of fluid (water, milk, etc.).…”

Effects of dietary viscosity and energy density on total daily energy consumption by young Peruvian children

“…A third, particularly intriguing possibility is that the effects of amylase liquefaction observed within the individual substudies were not due only to viscosity reduction per se, but to other aspects of amylase treatment. For example, it is conceivable that prior hydrolysis of dietary starch resulted in less undigested carbohydrate reaching the colon, where it can produce discomfort and possibly suppression of appetite (19). Further studies will be necessary to clarify these issues.…”