Preserving fruits

Fruits stay fresh for longer durations in tin cans compared to plastic packaging in hot conditions, says William Porter, food chemist at the Army Soldier Systems Command in Natick, Massachusetts, USA. This was discovered in 1991 during the Gulf War, when the caterers had problems with fruit turning brown and developing an odour. This prompted Porter and his colleagues to find out the factors that affected fruit preservation. Vitamin C, used as a preservative in fruit, combines with amino acids to form aldehydes, chemicals that cause the smell. Tin containers chemically reduce vitamin C preventing its reaction with amino acids in fruits, he explains ( New Scientist , Vol 154, No 2079).