Does vitamin C survive boiling?
Yes, it mostly does survive heating. It seems that at 70°C vitamin C is denatured so it should be preserved (heated) below 70°C to reduce the heat damage to a minimum.
I like especially the black current jam and buy it sweetened with sorbitol (erythritol or xylitol are good sweeteners too but not sugar or artificial sweeteners).
A blackcurrant jam may be considered as a good source of vitamins and antioxidants after one year, if certain precautions concerning manufacture and storage conditions are taken.
Blackcurrant (Ribes nigrum) jam was manufactured with the aim of producing a jam with a low sugar content, and without any additives.
Four temperatures were investigated, namely 60°, 76°, 92° anad 97°C.
Processing time varied between 1-20 min.
After processing, the highest content of ascorbic acid was found in the jam processed at 97°C for 1 min, which contained 63.3 ± 2.6 mg ascorbic acid/100 g jam.
At all combinations investigated more than 60% of the original amount of ascorbic acid was retained after manufacturing and packaging.
The jam made at 92°C was stored in a shelf-life study for 13 months. The jam was then stored at 8°C, ambient temperature and at 37°C. At ambient temperature the jam was stored both in dark and in daylight, at 8°C and at 37°C the jam was stored in dark.
After 13 months of storage, at 8°C, 60% of the amount of ascorbic acid and 29% of the amount of anthocyanins were retained.
In the jam stored at higher temperatures less of both was retained.
The ß-carotene in the jam was found to be stable throughout the whole shelf-life study.
Exposure to light did not have any effect on any of the components studied.
The degradation of anthocyanins was best described by a second-order reaction and the activation energy was determined to be 90 kJ/mol.
- A Study of Some Important Vitamins and Antioxidants in a Blackcurrant Jam with Low Sugar Content and Without Additives: International Journal of Food Sciences and Nutrition: Vol 48, No 1 (tandfonline.com)
- Effect of temperature on Vitamin C content – 1141 Words | Bartleby