Sulfite residues on litchi fruit treated with sulfur dioxide

Hot water treatment of litchi at 49 degrees C for 20 min proposed as insect disinfestation treatment results in peel damage. When combined with a sulfur dioxide treatment, this damage was prevented with residue in the edible aril on a fresh mass basis of less than 5 mg kg(-1). The non-edible peel sulfite residues were 388 mg kg(-1) immediately after treatment declining to 125 mg kg(-1) after 2 days at 22 degrees C and 5 days at 1 degrees C. Hot air treated fruit had significantly lower aril sulfite residue than hot water treated fruit. Fumigation load factor significantly influenced peel and aril sulfite residues; at 53 kg m(-3), aril sulfite residue were 1 mg kg(-1). It was therefore possible to protect litchi pericarp color and not increase the edible aril sulfite residues above background. (C) 1998 Elsevier Science B.V. All rights reserved.