Biofortification of chromium in fenugreek seeds

J Trace Elem Med Biol. 2020 Apr 9:61:126521. doi: 10.1016/j.jtemb.2020.126521. Online ahead of print.

Abstract

Background: Fenugreek and chromium are known to have anti-diabetic properties and this has been well demonstrated by multiple studies. Researches have been undertaken to study thebiofortification of chromium (Cr3+) in fenugreek. Some of the researchers have studied the biofortification from the soil irrigated with tannery waste water or from soil amended by tannery-sludge, with a view of enhancing the anti-diabetic effect of fenugreek plants. The present research work was also undertaken to increase the chromium content of fenugreek seeds, but through direct treatment of chromium picolinate solution to fenugreek seeds.

Methods: Fenugreek seeds were procured and divided in four groups having three batches of 10 g seeds- treatment1, treatment2, control1 and control2. Control1 group was kept raw and was given no treatment and control2 group was germinated using double distilled water. Treatment1 and treatment2, on the other hand, were given treatment of 0.02 g and 0.04 g chromium picolinate solution, on first day and 0.01 g and 0.02 g chromium picolinate solution on second day, respectively. The germinated samples were then completely dried, powdered, digested with di-acid mixture and assayed using Inductively Coupled Plasma optical emission spectrometry method for chromium content. The treatment1 sample was selected for further nutritional analysis along with control1 and control2 group to compare the nutritional composition of raw, germinated and chromium treated fenugreek seed flour. Fifteen sprouts from treatment1 group (treatment1A group) and fifteen sprouts from control2 group (control3 group) were sown in earthen pots for the analysis of chromium content in seeds of new plants.

Results: The fenugreek seeds treated with two different concentrations of chromium picolinate viz. treatment1 and treatment2 group attained 55 and 80 times higher chromium content as compared to control2 group, respectively. All the estimated minerals and bioactive compounds were significantly high (p ≤ 0.01) in germinated fenugreek seed flour and chromium treated fenugreek seed flour compared to raw fenugreek seed flour. Germinated fenugreek seed flour and chromium treated fenugreek seed flour were statistically comparable to each other in respect of all the parameters analysed. Hence, it was evident that enriching fenugreek seeds with chromium, did not affect the nutritional content of fenugreek seed by any mean. Also, there was no significant difference between the chromium content in seeds of control3 group and T1A group.

Conclusions: Treatment of fenugreek seeds with chromium solution seems to be an efficient and safe method for increasing their chromium concentration as compared to application of chromium to the soil for biofortification with minimal to no chance of chromium accumulation and inheritance in next generation plants. However, there is a need of more research to see how reliable these observations would be when different chromium salts and/or varied chromium concentration are used.

Keywords: Biofortification; Chromium; Fenugreek seeds; Germination; Nutritional analysis; Optical emission spectrometry.