Macromolecular Traits in the African Rice Oryza glaberrimaand in Glaberrima/Sativa Crosses, and Their Relevance to Processing

• Autores: Mauro Marengo, Alberto Barbiroli, Francesco Bonomi, Maria Cristina Casiraghi, Alessandra Marti, Maria Ambrogina Pagani, John Manful, Seth Graham‐Acquaah, Enzio Ragg, Dimitrios Fessas, Johannes A. Hogenboom, Stefania Iametti
• Localización: Journal of food science, ISSN 0022-1147, Vol. 82, Nº 10, 2017, págs. 2298-2305
• Idioma: inglés
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• Resumen

  • Molecular properties of proteins and starch were investigated in 2 accessions of Oryza glaberrimaand Oryza sativa, and in one NERICA cross between the 2 species, to assess traits that could be relevant to transformation into specific foods. Protein nature and organization in O. glaberrimawere different from those in O. sativaand in NERICA. Despite the similar cysteine content in all samples, thiol accessibility in O. glaberrimaproteins was higher than in NERICA or in O. sativa. Inter‐protein disulphide bonds were important for the formation of protein aggregates in O. glaberrima, whereas non‐covalent protein‐protein interactions were relevant in NERICA and O. sativa. DSC and NMR studies indicated only minor differences in the structure of starch in these species, as also made evident by their microstructural features. Nevertheless, starch gelatinization in O. glaberrimawas very different from what was observed in O. sativaand NERICA. The content of soluble species in gelatinized starch from the various species in the presence/absence of treatments with specific enzymes indicated that release of small starch breakdown products was lowest in O. glaberrima, in particular from the amylopectin component. These findings may explain the low glycemic index of O. glaberrima, and provide a rationale for extending the use of O. glaberrimain the production of specific rice‐based products, thus improving the economic value and the market appeal of African crops. The structural features of proteins and starch in O. glaberrimaare very different from those in O. sativaand in the NERICA cross. These results appear useful as for extending the use of O. glaberrimacultivars in the design and production of specific rice‐based products (for example, pasta), that might, in turn, improve the economic value and the market appeal of locally sourced raw materials, by introducing added‐value products on the African market.