The Effects of Low-dose X-ray Irradiation on Fermentation Products of Kefir

Background: Fermented food products are an inherent element of the human diet throughout the world owing to their health benefits. Kefir grains are a starter culture containing yeast and bacteria, which are classified as fermented dairy products. The present study aimed to investigate the effects of low-dose X-ray irradiation on kefir grains and the fermentation constituents. Methods: Five grams of kefir grains was added to nine dishes. Three dishes were irradiated to ۴۰cGy, three dishes were irradiated to ۸۰cGy X-ray, and three dishes remained non-irradiated as the control group. The chemical properties of the kefir samples (lactic acid, protein, fat, and lactose concentrations) were investigated after X-ray irradiation using standard methods. Results: The contents of lactic acid, protein, and lactose increased in the samples irradiated to ۸۰cGy X-ray (P < ۰.۰۵), while their fat content decreased (P < ۰.۰۵). No significant differences were observed between the ۴۰cGy X-ray samples and controls. Conclusion: According to the results, ۸۰cGy X-ray irradiation affected the kefir grains and increased their protein, lactose, and lactic acid, while decreasing the fat content, which makes milk consumption more convenient for those with high blood lipid levels.

Keywords:

Kefir , X-ray irradiation , Chemical properties