Effect of temperature, oxygen and light on the degradation of β-carotene, lutein and α-tocopherol in spray-dried spinach juice powder during storage

The aim of this study was to evaluate the interaction between packaging parameters (transmission of light and oxygen) and storage temperatures (4, 20, 40 degrees C) on nutrient retention of Spinach (Spinacia oleracea) juice, spray-dried in the absence of an added encapsulant. beta-Carotene was more susceptible to degradation compared with lutein and alpha-tocopherol. Under our experimental conditions, it was observed that excluding low fluorescent light intensity and air by vacuum packaging at 20 degrees C did not seem to improve nutrient retention loss over time (p > 0.05). The rate of beta-carotene, lutein and alpha-tocopherol loss displayed first order reaction kinetic with low activation energy of 0.665, 2.650 and 13.893 kJ/mol for vacuum, and 1.089, 4.923 and 14.142 kJ/mol for non-vacuum, respectively. The reaction kinetics and half-life for beta-carotene, lutein and alpha-tocopherol at 4 degrees C and non-vacuumed were 2.2 x 10(-2), 1.2 x 10(-2), and 0.8 x 10(-2) day(-1), and 32.08, 58.25 and 85.37 day, respectively.