Contamination of flexible pouches challenged by immersion biotesting

• Published in: Journal of food protection Vol. 59; no. 7; pp. 764 - 767
• Main Authors: Blakistone, B.A. (National Food Processors Association, Washington, DC.), Keller, S.W, Marcy, J.E, Lacy, G.H, Hackney, C.R, Carter, W.H. Jr
• Format: Journal Article
• Language: English
• Published: Des Moines, IA International Association of Milk, Food and Environmental Sanitarians 01.07.1996
• Subjects: ALIMENTOS; ALMACENAMIENTO; Biological and medical sciences; BIOTECHNOLOGIE; BIOTECNOLOGIA; CONDITIONNEMENT; CONTAMINACION BIOLOGICA; CONTAMINATION BIOLOGIQUE; EMPAQUETADO; ENSAYO; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Handling, storage, packaging, transport; PERDIDAS; PERTE; PRODUIT ALIMENTAIRE; PSEUDOMONAS; Pseudomonas fragi; RECIPIENT; RECIPIENTES; STOCKAGE; TESTAGE; Packaging; Immersion test; Foodstuff; Biological contamination; Quality control; Analytical method; package integrity; Biotesting; channel leaks
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X-59.7.764

Immersion biotesting has long been used to challenge packages, particularly cans, for pinholes and channel leaks. Such testing for all types of plastic packaging may not be appropriate because some packages (e.g., aseptic, hot fill) are not exposed to water. As the food-packaging industry develops alternative environmental biotests there is a need to benchmark them against traditional immersion testing. The purpose of this research was to examine the threshold of critical-defect dimensions using artificially created channel leaks of 10 and 20 pm and 5- and 10-mm lengths sealed into plastic pouches which were subsequently tested by immersion at 10(2) and 10(6) CFU of motile and nonmotile Pseudomonas fragi TM849 per ml. Forty-four percent (44%) of the pouches tested became contaminated, indicating the threshold defect value is below 10 micrometers. Microbial ingress was significant (P 0.05) for motile test organisms with a concentration of 10(6) CFU/ml. The interaction of concentration and time was also significant at 10(2) CFU/ml at 30 min exposure and 10(6) CFU/ml at 15 min. Channel length was not statistically significant. The markedly greater contamination rate using immersion testing versus that of aerosol testing highlights the importance of using test methods that reflect environmental exposure conditions of the packages