Degradation of ascorbic acid in Yemeni citrus fruits during storage

الملخص EN

Yemeni citrus fruits were analyzed for their ascorbic acid (vitamin C) content, by a titration method involving 2,6-Dichlorophenol indophenol as an oxidizing agent.

The initial ascorbic acid contents of abusurrah, valancia, lime and mandarin concentrates were 31.88, 31.52, 19.31 and 12.27 mg/100 ml respectively.

Ascorbic acid contents of the fruits were found to lie within the values reported in the literature.

Retention of ascorbic acid in citrus fruits juice during storage was investigated.

The effects of storage temperature 0ºC, 15ºC and 39ºC, storage time, air light and type of container were studied.

If the fresh juice is stored at 0º C for one week it loses 18% of ascorbic acid, while a higher loss of about 38% of the ascorbic acid was obtained for the juice stored at room temperature (39º C) for the same period of storage.

On the other hand, the results after three weeks of storage revealed that the best storage conditions for citrus fruits juice are at 0ºC.

Moreover, the results indicate that air light effects on ascorbic acid content by decreasing its value in all juice samples.

Also, ascorbic acid retention was a little higher in the samples conserved by opaque glass and plastic bottles compared to the transparent bottles.