Protein content and amino acid profile in Portuguese rice

According to INE, between 2010 and 2011, rice (Oryza sativa) availability in Portugal was 15.8 kg per capita per day, which represents the highest in Europe [1]. Rice amino acids profile evaluation is important to define the nutritional quality of different species contributing to choice of the varieties of rice to grow. This study aimed to quantify the total protein and amino acids profile in 15 cultivated accessions selected from the two major subspecies, Japonica and Indica, grown in Portuguese Sado and Ribatejo regions between 2009 and 2011. Total protein was determined by Kjeldahl method and the content of AA was measured by an Ultra Performance Liquid Chromatography of ACQUITY ™ UPLC ® (Waters) system equipped with a photodiode array detector (DAD) with a pre-derivatisation column 6-N-aminoquinolil hidroxisuccinimidil carbamate, after microwave acid hydrolysis. Analysis of the results emphasizes that there was no significant difference between Japonica varieties (6.4 ± 0.5 g/100g) and Indica (7.0 ± 1.6 g/100g) in relation to total protein content. Amino acids score, as defined by WHO/FAO/UNU [2], was between 0.55 (lysine) and 3.24 (aromatic amino acids). Lysine was the only limiting AA (score