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

Abstract

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 3.9 and 5.0. Acidification, blanching, and addition of EDTA preserved vitamin C mainly as L-AA, while complete conversion into DHAA was observed in purée at pH 5.0. The retention of all-trans-β-carotene was between 65 and 72%, with the highest value in purée with EDTA and the lowest value in purée of blanched mango. The ratio of 13-cis-β-carotene in fresh mango was 8.2 ± 0.5% that increased significantly after blanching and in purée at pH 5.0. 707

Drying Kinetics and Quality of Dehydrated Cranberries Pretreated by Traditional and Innovative Techniques

“…Such results are probably linked to the denaturation of enzymes responsible for oxidation of ascorbic acid by the means of temperature increment. This explanation can be supported by the literature data according to HTST blanching can cause almost complete inactivation of ascorbic acid oxidase (AAO; Guiamba & Svanberg, ) and thus influencing positively the vitamin C retention after drying (Santos & Silva, ). What is interesting, samples pretreated by combined method did not exhibited higher retention of vitamin C in comparison to blanched fruits.…”

“…Such results are probably linked to the denaturation of enzymes responsible for oxidation of ascorbic acid by the means of temperature increment. This explanation can be supported by the literature data according to HTST blanching can cause almost complete inactivation of ascorbic acid oxidase (AAO; Guiamba & Svanberg, 2016) and thus Food Engineering, Materials Science, & Nanotechnology Dehydrated cranberries . .…”

Enhancing the retention of -carotene and vitamin C in dried mango using alternative blanching processes

“…The procedure to measure the PPO enzyme activity in the mango samples has earlier been reported in detail (Guiamba and Svanberg, 2016) and was based on the method described by Palou et al (1999) and Ndiaye et al (2009). After extraction of the PPO enzyme using a McIlvaine citric-phosphate buffer (pH 6.5) and addition of a 4-methylcatecol solution, the colour reaction was recorded by measuring the absorbance at 420 nm using a Cary 50Bio UV-visible spectrophotometer.…”

“…The activity of AAO in the mango samples was measured according to the procedure earlier described in detail by Guiamba and Svanberg (2016) and based on the method according to Oberbacher and Vines (1963) as modified by Munyaka et al (2010). The AAO enzyme was extracted from the mango samples using a phosphate buffer (0.1 M, pH 5.6, 0.5 mM EDTA) and the AAO activity was determined by measuring the decrease in substrate concentration (0.5 mM L-AA) using a Cary 50Bio UVvisible spectrophotometer at 265 nm.…”

“…Vitamin C and total ascorbic acid was determined using an HPLC method that was equipped with an electrochemical detector and the procedure was described in detail by Guiamba and Svanberg (2016) with minor modifications. Approximately 1.5 g of fresh or blanched mango and 0.5 g of dried mango was homogenized in an extraction buffer (20 mM NaH2PO4, pH 2.1, 1 mM EDTA) and aliquots of the supernatant were diluted both in McIlvaine citricphosphate buffer (pH 4.5) alone and McIlvaine citric-phosphate buffer containing 0.312 mM TCEP (Tris[2-carboxyethyl]phosphine hydrochloride).…”