A combination process including ionizing radiation for hygienization and shelf life extension of leafy vegetables

Abstract

Raw leafy greens are commonly associated with global foodborne outbreaks due to pathogenic contaminants. In the current study, greens, such as spinach (S<em>pinacia oleracea </em>L.), coriander <em>(Coriandrum sativum </em>L.) and mint (<em>Mentha spicata </em>L.) showed presence of coliforms (including <em>E. coli</em>)along with other aerobic microbes, yeast and molds. These vegetables mostly consumed in raw or culinary purpose, and hence increase the chances of food borne illnesses. Moreover, the leafy greens are perishable. In this context, we optimized a combination process including radiation treatment to achieve hygienization and shelf life extension of these leafy green vegetables. The combination treatment comprising potable water wash, chlorination (NaOCl-200 ppm) followed by irradiation (2 kGy using electron beam or gamma) was developed, and the processed samples showed keeping quality up to 15 days at 4-6°C, whereas control samples spoiled within two days. The treatment resulted in coliform count below detection level while retaining the nutritional, phenolic content and organoleptic qualities. Thus, the combination treatment could ensure safety, keeping quality enhancement of perishable leafy greens and to control global food outbreaks. Electron beam over gamma processing found to be a commercial viable option due to its high throughput and equal efficacy in microbial decontamination.