Effects of blanching, acidification, or addition of EDTA on vitamin C and β-carotene stability during mango purée preparation.

The impact of acidification with citric acid, addition of EDTA or water blanching at high temperature, and short time (HTST) conducted at 90°C for 4 min, on the retention of vitamin C (L-AA and DHAA) and β-carotene was studied in mango purée 30 min after crushing. HTST blanching prior to matrix disruption into purée resulted in complete inactivation of polyphenol oxidase (PPO) and minor residual activity (8%) of ascorbic acid oxidase (AAO). The retention of total vitamin C was 100% in blanched purées and in purée with EDTA and about 90% in purées at pH 3.

Effect of Infrared Blanching on Enzyme Activity and Retention of β-Carotene and Vitamin C in Dried Mango.

The objectives of this work were to evaluate infrared (IR) dry blanching in comparison with conventional water blanching prior to hot air drying of mango to inactivate polyphenol oxidase (PPO) and ascorbic acid oxidase (AAO) enzymes, and to study its effect on color change and retention of vitamin C and β-carotene. Mango cylinders were blanched under similar temperature-time conditions either by IR heating or by immersion in a water bath during 2 min at 90 °C (high-temperature-short-time-HTST) or for 10 min at 65 °C (low-temperature-long-time-LTLT). After blanching mango was hot air dried at 70 °C.