Central Food Technological Research Institute, Mysore
1. The tin content of canned mangoes using thirteen important varieties and of four other canned fruits has been determined and the results reported.
2. The tin content of canned mangoes in plain cans is small and well within limits even after 12–15 months of storage under unfavourable and high storage temperatures.
3. In the case of Neelum mango, after 42 months of storage at a temperature range of.80–108°F, the tin content was only 76.8 mg. per kg. The tin content of canned Hirnayuddin mango after 12 months of storage was only 27.4 mg. per kg. These values are far less than those for some of the English canned fruits like plums, gieengages, cherries, etc. -
4. When Hirnayuddin mango was canned in a lacquered can, the tin content after 43 months of storage was only 28.2 mg/kg which is really a small figure.
5. In the case of other canned fruits also like grape fruit, pummelo and pear in plain cans, the tin content after about 12 months of storge was small and was 49, 26 and 32 mg/kg. respectively.
6. In the case of canned jack fruit bulb in plain cans, after six months storage, the tin content was only 11.4 mg./kg. The effect on this of adding acid to the covering syrup to lower the pH from 5.2 to a safe limit for normal processing is being investigated.
7. After 10–12 months of storage, inversion’ of the sugars in the syrup is almost complete in the case of the more acid mangoes. In the case of fruits which are comparatively less acidic, the inversion is not complete over this period of storage. In the case of Baneshan, the inversion is. about 60 per cent after 14 months, while in the case of Hirnayuddin, the inversion is only 28 per cent at the end of 12 months. In the case of Neelum, the inversion is complete after 42 months of storage.
