Comparability of in vitro bioaccessibility of carotenoids with their yolk content in laying hens for dent maize hybrids differing in kernel traits

Abstract

The aim of the study was to investigate the relationship between in vitro bioaccessibility and in vivo bioavailability, expressed as yolk content, of maize carotenoids. INFOGEST protocol was used for in vitro bioaccessibility, whereas carotenoid content was analysed in the yolk of laying hens fed complete feeds differing only in the hybrid. Fourteen commercial dent hybrids were selected based on preliminary screening of 103 hybrids to represent a wide range of carotenoid profiles in addition to physical and chemical traits. The amount of bioaccessible carotenoids and their yolk content generally decreased as follows: zeaxanthin > lutein > β-cryptoxanthin > α-cryptoxanthin > β-carotene. Across hybrids, carotenoid bioaccessibility and yolk content correlated positively with their content in kernel, with the exception of β-carotene. However, some hybrids with similar content of individual carotenoids in kernel had contrasting in vitro bioaccessibility and yolk deposition, clearly indicating hybrid-specific responses influenced by other kernel traits. In general, kernel traits associated with greater hardness, such as zein content, test weight, kernel density and Stenvert hardness, correlated positively with zeaxanthin, β-cryptoxanthin and total carotenoids. Traits indicating softer kernel texture, such as total starch content and breakage susceptibility, correlated positively with bioaccessible and bioavailable lutein and β-carotene. Results showed that in vitro bioaccessibility may be a good indicator of the potential content of carotenoids in the yolk, with the exception of β-carotene, and that hybrid-specific responses were associated with physical and chemical traits of maize kernel.