Joint study on the development of ISO/IDF method for protein digestibility and in vitro DIAAS analysis in different food matrices

Project no. 29679 · Status: Kapanmış · 2023

Summary

The Food and Agriculture Organization of the United Nations (FAO) recommends the use of the Digestible Indispensible Amino Acid Score (DIAAS), based on digestion completed in the small intestine of humans or pigs, to determine protein quality. Ideally, true small intestinal digestibility in humans should be determined with naso-ileal tubes, but due to impracticality and ethical constraints, it was proposed in 2020 to perform animal experiments on pigs and rats with fistulated ileal during the growth period. However, the FAO/WHO emphasized the need to develop in vitro methods due to reproducibility, ethical values and cost and stated that it supports the development of validated in vitro assays that will correlate with in vivo assays. The in vitro digestion protocol developed by the INFOGEST working group was analyzed with different samples and the correlation of the method with in vivo results was determined. In the following phase, static in vitro digestion analyses were to be carried out on standard samples in laboratories in different countries, the results compared, and the reproducibility and validation of the method ensured. A new study was organised with the participation of different laboratories to verify the reproducibility of the developed method and subsequently obtain the ISO/IDF certificate. In this context, after the first study organized in 2022, it was planned to study 5 different milk-based (milk proteins) and 2 different plant protein samples sent to all laboratories from a single center for the second time with the INFOGEST 2.0 protocol. In this study, the INFOGEST 2.0 in vitro digestion protocol was applied to the samples, and then protein digestibility (OPA method and total nitrogen analysis) and protein profile (SDS-PAGE analysis) were evaluated. The results obtained in our laboratory were similar to the results obtained from other laboratories, and it was concluded that the applied in vitro protocol was suitable for determining protein digestibility. After the validation of the data obtained from the laboratories where the method was studied, an application to the ISO/IDF (International Organization for Standardization/International Dairy Federation) standard will be made.

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