Microbial content of commercial South African high-moisture dried fruits.
OBJECTIVE
The aim was to evaluate commercially available South African high-moisture dried fruits (HMDF) for the microbial, moisture and SO2 contents, as well as aw and pH.


RESULTS
The microbial content of commercially available HMDF was evaluated using nine different growth media. The moisture content, aw) SO2 and pH of each product were determined using standard analytical methods. It was found that the highest total aerobic counts were generated from high-moisture dried (HMD) prunes and raisins. The most frequent spoilers were members of the genus Bacillus. Fungal counts were also very high in the apricot products, exceeding the limit of 1000 CFU g(-1) as set by HMDF producers. Members of the genus Staphylococcus were found in the HMD raisins and Salmonella and thermoduric organisms were isolated from the HMD prunes.


CONCLUSIONS
The microbial levels of South African HMDF were within the limits set, with the exception of apricots.


CONCLUSIONS
The study shows the presence of Salmonella, Staphylococcus and Clostridium in South African HMDF. The presence of thermoduric organisms indicated that the current pasteurization process is not adequate and that the addition of preservatives would be an additional method to ensure safety and quality.
Witthuhn
R C
RC
Department of Food Science, Stellenbosch University, Matieland, South Africa. rcwit@sun.ac.za
Engelbrecht
S
S
Joubert
E
E
Britz
T J
TJ
D001407:Bacillus / Q000302:isolation & purification; D001419:Bacteria / Q000302:isolation & purification*; D003013:Clostridium / Q000302:isolation & purification; D005506:Food Contamination; D005516:Food Microbiology; D005519:Food Preservation; D005638:Fruit; D005658:Fungi / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D012475:Salmonella / Q000302:isolation & purification; D013011:Sorbic Acid / Q000032:analysis; D013019:South Africa; D013210:Staphylococcus / Q000302:isolation & purification; D013458:Sulfur Dioxide / Q000032:analysis; D013997:Time Factors
D013458:Sulfur Dioxide; D013011:Sorbic Acid