Since the introduction of frozen orange concentrate approximately ten years ago, a number of papers have appeared in the literature pertaining to coliformsb in this product. Some of the investigators who have contributed knowledge in this field are Beisel (2), Beisel and Troy (3), Brokaw ( 5 ) , Ferraro and Appleman (7), Hahn and Appleman (8), Martinez and Appleman (lo), Patrick (15, 16), Teunisson and Hall (191, Wolford (23,24,25) and Wolford and Berry (26,27). The results of some of these investigators have varied considerably. For instance, Martinez and Appleman (10) and Ferraro and Appleman (7) were unable to isolate coliforms from any of the samples of orange juice examined, whereas Wolford (25) isolated 236 coliforms from 79 samples of juice and found 72% of the isolates were Aerobacter aerogenes, 19.5Yi Escherichia coli and 8.570 intermediates. Patrick (16), however, selected certain isolates for study and presented evidence to show that of 217 coliforms isolated from orange concentrate and damaged oranges, 64% were Escherichia coli types, 19% were Aerobacter aerogenes types and 17 % were intermediate types.I n order to learn more about the prevalance of certain types of coliforms aiid related organisms in orange juice, it was decided to determine the identity of some of the Gram negative rods isolated from samples of orange juice by use of Violet Red Bile agar, a selective medium for coliforms.Data show that of the cultures isolated in this investigation, 65% were Aerobacter aerogenes types and 35% intermediate types. NO Escherichia coli types were isolated. Aerobacter aerogenes, Escherichia freundii, Escherichia intermedium, Xerratia marcescens and members of the genus Erwinia were isolated from one sample of orange juice.
