Formulation of a nasogastric liquid feed and shelf-life extension using gamma radiation

Nasogastric liquid feed formulation (NGLF) was developed for immunocompromised patients who are vulnerable targets of pathogenic assault. NGLF consisted of cereals, pulses, vegetables, and milk powder to provide balanced nutrients; however, the shelf life was only a few hours because this product was highly prone to microbial contamination and proliferation due to its high water content and rich nutrients. Postpreparation storage and distribution was very difficult, even at chilled temperatures. To overcome this problem, the NGLF was irradiated at various doses (2.5 to 10 kGy). Gamma irradiation at 10 kGy reduced the microbial load to nondetectable levels, and the product could be stored up to 1 month without any detectable increase in microbial load. The sensory evaluation did not indicate differences between the nonirradiated fresh, irradiated fresh, and stored samples. Nutritional quality in terms of total carbohydrates, dietary fiber, proteins, calories, vitamins A and C, and the micronutrients calcium, iron, and zinc was not affected by irradiation. NGLF also possessed antimutagenic potential against ethylmethanesulphonate-induced mutagenesis in Escherichia coli cells as evaluated by the rifampin resistance assay. This property of NGLF remained unchanged even after exposure to a 10-kGy dose of gamma radiation. Thus, irradiated NGLF seemed to be a safe and wholesome food for immunocompromised patients.