Extending shelf-life and nutritive value of green beans (Phaseolus vulgaris L.), by controlled atmosphere storage: micronutrients

Controlled atmosphere (CA) storage has become a useful technique for extending vegetables shelf-life. The aim of this work is to select the most suitable conditions for green beans storage under CA, for the maintenance of micronutrients (vitamins and mineral content). Samples were stored at 8 °C, under different conditions (normal atmospheric air, 5%O2+3%CO2, 3%O2+3%CO2 and 1%O2+3%CO2), and analyzed periodically during 1 month for ash and individual mineral elements (atomic absorption spectroscopy), carotenoids (spectrophotometry), vitamins B1 and B2 (spectrofluorometry), vitamins B6 (colorimetry) and vitamin C (HPLC–UV). Statistical analysis (ANOVA) and Duncanʹs tests were applied to the analytical data to evaluate the effects of the treatments applied. A weighted least squares polynomial plot was applied to vitamin C data to establish its degradation kinetics. The conditions 3% O2+3%CO2 at 8 °C was selected as the best one to extend shelf-life and preserve the nutritive value of this vegetable, with a 75% total vitamin C retention at 8 days storage.