Studying the effect of plant nutrition and variety on the nutritional value of teff grown in Israel

Teff (Eragrostis tef) is an annual cereal, a staple food in Ethiopia, where it is indigenous. Teff is rich in nutritionally important minerals, and is also a gluten free, high in polyphenols and dietary fiber, with a low glycemic index. Recently there is a growing interest in teff, owing to its nutritional values and being gluten free. In Israel there is a high demand for teff by the local Ethiopian community, and lately it has been commercially grown in the Golan Heights and in the Negev area. Our aim was to study the effect of nitrogen (N), phosphorus (P) and potassium (K) fertilization and variety on the nutritional value of teff grown in Israel. For this, red and white teff seeds from commercial varieties were grown in pots, in a greenhouse located at the Gilat Center. Plants were exposed to 5 N levels in an irrigation solution (10,20,40,80, 120 ppm), 4 P levels (1,3,6, 12 ppm) and 4 K levels (10,20,40, 80 ppm), grown to full maturity and harvested manually. Mineral concentration, total phenolic content and fatty acid composition were measured. Results showed that for increasing N, P and K levels fertilization, a significant decrease in zinc contents was observed, mainly in the red variety. In addition, N and P fertilization resulted in a significant decrease in manganese contents, in both red and white cultivars. In addition, polyphenol contents increased with increasing N fertilization in both white and red varieties. Fatty acid analysis showed that N fertilization resulted in an increase in polyunsaturated fatty acids (PUFA), accompanied by a decrease in saturated fatty acids (SFA), with no significant changes in monounsaturated fatty acid (MUFA) levels. Today’s costumers are aware of the health benefits of food, and are willing to pay higher prices for healthier foods. We showed that plant nutrition regime greatly affects teff`s nutritional composition, indicating that fertilization should be a delicate balance between physiological needs, yield outputs and nutritional outcomes.