Application of surface-active substances produced by Nocardia vaccinii IMB B-7405 for the treatment of vegetables

Abstract

Introduction. Application of surface-active substances (SAS) produced by Nocardia vaccinii IMV B- 7405 for shelf live extension of vegetables was studied. Materials and methods. Organic vegetables such as tomato, cucumbers, and squashes were washed with the solution of SAS produced by N. vaccinii IMV B-7405 with concentrations of 0.25 or 0.5 g/L. Microbiological analysis was done before the beginning of the vegetables storage. Evaluation of vegetable quality was conducted by viewing during time of the storage. Results and discussion. The results of our research showed the efficiency of the application of biosurfactant produced by Nocardia vaccinii IMV B-7405 using industrial wastes for shelf life extension of vegetables. Results of visible observations as well as microbiological analysis showed that the treatment of vegetables with SAS solutions at the concentrations of 0.25 and 0.5 g/L was more effective than washing them with tap water. The total number of heterotrophic bacteria and fungi in the samples decreased after treatment of vegetables with SAS of N. vaccinii IMV B-7405 by 16-34 and 3-14 times, respectively, meanwhile the washing of vegetables with tap water decreased total microbial number only by 2-2.5 times. It was shown that vegetables washed with water spoiled faster than those treated with SAS solution. The advantages of application of this biosurfactant for vegetables post-harvest treatment are that (1) it can be used at the lower by 2-6 times concentration in comparison with other reported in literature microbial SAS, and (2) it can be produced using industrial wastes that will reduce the cost of its production. Conclusion. Biosurfactant produced by Nocardia vaccinii IMV B-7405 can be used for the treatment of vegetables to extent their shelf life.