You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Proposal of mechanism of the freeze-thaw fractionation of 7S and 11S globulins in soymilk. The mechanism underlying the freeze-thaw fractionation of 7S and 11S globulins in soymilk was investigated. Freeze-thawed soymilk demonstrated an increased particle size compared with raw soymilk. Further, when defatted raw soymilk was freeze-thawed, it was fractionated into 7S (supernatant) and 11S (precipitate) globulins, similar to what is found with freeze-thaw of raw soymilk. When raw soymilk samples with different ratios of 11S/7S were freeze-thawed, the 11S-deficient variety showed no precipitate. The addition of sodium sulphite or sodium dodecyl sulphate also inhibited precipitate formation after freeze-thawing, resulting in no fractionation. These results suggest that the fractionation is due to selective precipitation of aggregates of 11S globulins and/or 11S globulins and lipid complexes, in which the protein molecules interact through disulphide bonds and/or hydrophobic interactions.
{"Chemical": ["disulphide", "sodium dodecyl sulphate", "sodium sulphite"]}