Bacteriology of Slime in a Citrus‐processing Plant, With Special Reference to Coliforms

Wolford, E. R.; Berry, J. A.

doi:10.1111/j.1365-2621.1948.tb16630.x

“…

Available literature pertaining to the types of bacteria indigenous to citrus juices is very limited. Faville, Hill, and Parish (1) reported that bacteria comprised the majority of organisms isolated from samples of frozen concentrated orange juice and that Leucomostoc was the predominant genus present, while reports on the occurrence of coliform organisms by Patrick ( 6 ) , Wolford and Berry (11,12), and Wolford (10) constitute the remaining publications on this subject.Although the relatively high citric acid content of citrus juices exerts a bacteriostatic effect on most species of bacteria, experience resulting from 5 years of commercial production of frozen concentrated citrus juices indicates that from the standpoint of spoilage of the product, bacteria are probably of significance equal to or greater than normally-occurring yeasts and molds. Hayes (3), for example, has isolated strains of Lactobacillus brevis and Lactobacillus ~l a~t~r u~ which he believes were the causative organisms in several instances where spoilage had occurred in the lower-Brix stages of multiple-stage evaporators during low-temperature vacuum concentration of orange juice, Teunisson and Hall (a), on the other hand, studied organisms isolated from the surfaces of processing equipment in citrus canneries and concluded that "bacteria are probably not a major factor in influencing the quality of orange juice. '

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mentioning

confidence: 99%

“…Available literature pertaining to the types of bacteria indigenous to citrus juices is very limited. Faville, Hill, and Parish (1) reported that bacteria comprised the majority of organisms isolated from samples of frozen concentrated orange juice and that Leucomostoc was the predominant genus present, while reports on the occurrence of coliform organisms by Patrick ( 6 ) , Wolford and Berry (11,12), and Wolford (10) constitute the remaining publications on this subject.…”

mentioning

confidence: 99%

ACID‐TOLERANT BACTERIA IN CITRUS JUICES^a

Faville

¹

,

Hill

²

1952

Journal of Food Science

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Available literature pertaining to the types of bacteria indigenous to citrus juices is very limited. Faville, Hill, and Parish (1) reported that bacteria comprised the majority of organisms isolated from samples of frozen concentrated orange juice and that Leucomostoc was the predominant genus present, while reports on the occurrence of coliform organisms by Patrick ( 6 ) , Wolford and Berry (11,12), and Wolford (10) constitute the remaining publications on this subject.Although the relatively high citric acid content of citrus juices exerts a bacteriostatic effect on most species of bacteria, experience resulting from 5 years of commercial production of frozen concentrated citrus juices indicates that from the standpoint of spoilage of the product, bacteria are probably of significance equal to or greater than normally-occurring yeasts and molds. Hayes (3), for example, has isolated strains of Lactobacillus brevis and Lactobacillus ~l a~t~r u~ which he believes were the causative organisms in several instances where spoilage had occurred in the lowerBrix stages of multiple-stage evaporators during low-temperature vacuum concentration of orange juice, Teunisson and Hall (a), on the other hand, studied organisms isolated from the surfaces of processing equipment in citrus canneries and concluded that "bacteria are probably not a major factor in influencing the quality of orange juice. ' ' Conflicting reports such as these have prompted this study of acid-tolerant bacteria in citrus juices. EXPERIMENTAL PROCEDURESource of organisms. Most organisms included in this study have been isolated from experimental lots of orange juice, both single-strength and partially concentrated, which have shown evidence of microbial activity. During the course of 2 seasons many such experimental lots of juice have been packed and stored a t different temperatures ranging from -8'F. (-22.2"C.) to 40°F. ( 4 5°C . ) . Certain of these packs, particularly those stored a t the higher temperatures, have developed "swells. " 011 microscopic examination these swells have been demonstrated to be caused by bacterial rather than yeaat activity, as might be expected.The remainder of the organisms studied were isolated from oranges partially or completely rotted internally. Some of these fruit showed very little or no external evidence of decomposition. The Hamlin oranges shown in Figure l illdstrate a bacterial rot of this type. Although the rotted fruit (right) cannot be easily distinguished from a sound fruit (left) except for a bro3n spot located at the stylar end (bottom right), the interior portion of the fruit (upper right) has almost completely deteriorated. I n this particular fruit the decomposition was most pronounced in the central cylinder and extended throughout the vesicles t o the albedo.

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