1 Interpretation of Experimental Data

The study employed multivariate statistical methods to analyze the morphological characteristics, proximate composition (including moisture, crude fiber, protein, fat, carbohydrates, and energy value), total phenolic and flavonoid contents, and antioxidant properties of 31 agro-ecotypic populations of fenugreek. Data analysis indicated significant differences in morphological characteristics and proximate composition among the different populations. For example, in seed samples, the highest ash content was 3.94%, the highest fat content was 7.94%, the highest crude fiber content was 10.3%, the highest protein content was 35.41%, and the highest carbohydrate content was 50.5%.

Figure 2 shows the total phenol content (TPC), total flavonoid content (TFC), and their radical scavenging activities (DPPH and FRAP) of the leaves and seeds of Trigonella foenum-graecum from 31 agro-ecotypic populations. From (a), it can be seen that there are significant differences in TPC and TFC content between the leaves and seeds of different ecotypic populations, with the leaves generally having higher TPC and TFC than the seeds. (b) shows the DPPH and FRAP activities, indicating that the antioxidant activity of the leaves is generally higher than that of the seeds, especially in populations such as Ahvaz and Kermanshah. These data suggest that the leaves of Trigonella foenum-graecum have advantages over the seeds in terms of antioxidant activity and phenolic content.

Figure 3 shows the bi-plot graph and correlation plot for the principal component analysis (PCA) based on the proximate composition, total phenolic content, total flavonoid content, and antioxidant activities of the leaves and seeds of Trigonella foenum-graecum from 31 agro-ecotypic populations. The PCA in (a) and (b) demonstrates significant differences in composition among different ecotypic populations, especially in crude fiber, protein, and carbohydrates. The correlations in (c) and (d) reveal the relationships between total phenolics, total flavonoids, and antioxidant activities. The antioxidant activity of the leaves (DPPH and FRAP) is positively correlated with total phenolics and total flavonoids (correlation coefficients of 0.50 and 0.68, respectively), while this correlation is relatively lower in seeds. These results indicate that the leaves have more pronounced antioxidant properties than the seeds, and there are significant associations among the components.

2 Insights of Research Results

Through an in-depth analysis of the experimental data, they found a significant correlation between the morphological characteristics and proximate composition of different agroecotypes. Specifically, leaf protein content showed a significant positive correlation with seed protein content and seed energy value, with correlation coefficients of r=0.78 and r=0.64, respectively. This indicates that higher leaf protein content corresponds to higher seed protein content and energy value. Additionally, they observed a significant negative correlation between leaf moisture content and both leaf protein content and leaf energy value, with correlation coefficients of r=-0.65 and r=-0.57, respectively. This means that populations with higher leaf moisture content have relatively lower leaf protein content and energy value. Further research also revealed a significant correlation between total phenolic and flavonoid contents and antioxidant performance. Specifically, the higher the total phenolic and flavonoid contents, the stronger the antioxidant performance of fenugreek. This finding indicates that these compounds significantly contribute to the antioxidant capacity of fenugreek, further supporting its potential as a functional food ingredient. Through these correlation analyses, they can better understand the relationship between the morphological and chemical characteristics of different agroecotypes, providing important insights for further breeding and functional studies.

3 Evaluation of the Research

This study, through a comprehensive analysis of different agroecotypes of fenugreek, reveals significant variability in morphological characteristics and chemical composition among these populations. The research methodology is scientifically rigorous, the data analysis is thorough, and the results are highly reliable. Experimental data indicate significant differences between populations in the proximate composition of leaves and seeds, total phenolic and flavonoid contents, and antioxidant performance. For instance, the seeds have higher protein, fat, and carbohydrate content, as well as significantly higher energy values compared to the leaves. These findings suggest that fenugreek seeds have important application potential in the food industry. Moreover, the study shows that the antioxidant performance of fenugreek leaves and seeds is closely related to their total phenolic and flavonoid contents, providing scientific evidence for the application of fenugreek in functional foods. Notably, the leaves of the Karaj ecotype and the seeds of the Mashhad ecotype, due to their superior nutritional and antioxidant properties, have potential for further commercial development.

4 Concluding Remarks

This study demonstrates significant differences in morphological characteristics, proximate composition, total phenolic and flavonoid contents, and antioxidant performance among different agroecotypes of fenugreek in Iran. The results indicate that fenugreek seeds are rich in nutrients, with high levels of protein, fat, and carbohydrates, as well as high energy values. The leaves and seeds of these populations exhibit significant differences in antioxidant activity, mainly related to their total phenolic and flavonoid contents. There is notable variability in the ash, fat, crude fiber, protein, and carbohydrate contents of seeds among different populations, giving certain populations an advantage in specific nutritional components. For example, the seed protein content of some ecotypes is as high as 35.41%, while the fat content can reach 7.94%. This study provides scientific evidence for the application of fenugreek in the food industry and functional foods. The high nutritional content and antioxidant performance make fenugreek seeds have broad application potential, especially in the development of foods with high nutritional value and antioxidant functions.

5 Access Original Paper

Bakhtiar Z., Hassandokht M., Naghavi M.R., and Mirjalili M.H., 2024, Variability in proximate composition, phytochemical traits and antioxidant properties of Iranian agro-ecotypic populations of fenugreek (Trigonella foenum-graecum L.), Sci. Rep., 14(1): 87. https://doi.org/10.1038/s41598-023-50699-9

Acknowledgements

I would like to thank the journal "Scientific Reports" for its open access policy, which allows readers free access to this valuable research. I am grateful to Ziba Bakhtia, Mohammadreza Hassandokht and Mohammad Hossein Mirjalili (two corresponding authors) and their research team for their work, providing an excellent case study for the legume research community. Due to different perspectives of reviewers on the understanding of the paper, I apologize if there are any discrepancies between the reviewers' perspectives on the data and results of the paper and the intentions of the authors.