Characteristics of Coliform Bacteria from Olives.

Coliform bacteria have long been associated with a "gassy" deterioration of olives. This deterioration may be characterized by the formation of blisters, resulting from accumulation of gases which separate the skin from the flesh of the olives or by the formation of fissures directly under the skin which may extend to the pit of the fruit as shown in Plate 1. The decomposition is not confined to any one type or variety of olive, but occurs more frequently in olives treated with caustic solutions for the production of "ripe" olives (either "ripe" or ''green ripe" canned olives of commerce) or for green fermented olives. The sodium hydroxide solutions (0.5 to 1.5 per cent) used for destruction of the natural bitterness of the olive and to facilitate production of the color of the finished product renders the olive more susceptible to invasion by destroying the waxy covering of the skin and by neutralizing the acidity. The spoilage most frequently occurs upon leaching with water to remove the spent caustic. Coliform spoilage also has been observed in olives during preliminary storage in salt brines before treating with caustic.I Kossowicz (1908) was probably the first to associate coliform bacteria with decomposition of olives. More recently, Cruess and Guthier (1923), Alvarez (1926) and Tracy (1934) have investigated this problem. Several incompletely described bac-