Variation of lycopene and beta-carotene contents after harvesting of gac fruit and its prediction

Abstract

The effects were investigated of three different stages of harvesting, the storage time and sample preparation methods before extraction using a Waring blender (WBM) or ball mill (BMM) on the lycopene and β-carotene contents from the gac aril. It was found that after harvesting and being stored at 26 ± 1 °C and 24±1% RH for 15 d, the lycopene contents from the color break, medium ripe and fully ripe stages of gac fruits grown in Thailand were in the ranges 0.11–8.99 mg/100 g fresh weight (FW), 3.88–22.94 mg/100 g FW and 18.95–50.11 mg/100 g FW, respectively, while the β-carotene contents were in the ranges 0.002–4.82 mg/100 g FW, 0.31–13.59 mg/100 g FW and 22.68–39.16 mg/100 g FW, respectively. In addition, neither the WBM nor the BMM sample preparation method had any significant (p > 0.05) effect on the analysis of these phytonutrients. Gac fruit at the fully ripe stage after 6 d of storage provided the highest lycopene content of 50.11 ± 1.59 mg/100 g FW, while the β-carotene was found highest (39.16 ± 1.29 mg/100 g FW) from fully ripe stage fruit after 15 d storage or when they had spoiled. Without classifying the fruits according to harvesting stages, equations for mixed ripe fruit were able to predict the lycopene and β-carotene contents in the aril with coefficients of determination of 0.77 and 0.89 with standard errors of the estimate of 16.09 and 6.39, respectively.