H. B. Sowbhagya

Effect of Drying Methods on the Quality Characteristics of Fenugreek (Trigonella foenum-graecum) Greens

Different drying methods were investigated for efficient dehydration of fenugreek (Trigonella foenum-graecum) greens for optimal retention of color and its constituents. Accordingly, hot air (HA, 40°C, 58–63% RH), low humidity air (LHA, 40°C and 28–30% RH), and radiofrequency (RF, 40°C, 56–60% RH) were explored for efficient drying of fenugreek greens. The three single-layer drying models (Exponential, Page, and Modified Page) tested showed excellent fit (R2 = 0.92–0.99) for all three drying methods. The time required for drying with LHA and RF was less (∼27%), as compared to HA drying. LHA-dried fenugreek had superior green color and a more porous and uniform structure than those obtained from RF and HA drying. Aqueous methanolic (60:40) extract of fenugreek greens dehydrated by LHA exhibited the highest radical scavenging activity. Dehydrated fenugreek greens showed good consumer acceptance as well as shelf life.

Enrichment of Bio-Active Phthalides in Celery Seed Oil

Objective : To develop an efficient process to obtain a phthalide-enriched nutraceutical fraction from celery seed oil. Methods : Three approaches viz. , fractional distillation, column chromatography and solvent-solvent partition, have been used. Results : Fractional distillation of celery seed oil (13.7g) afforded i) a limonene-rich fraction (7.6g, 97% purity), ii) a fraction containing β-selinene (2.8 g, 90 % purity) and iii) one containing phthalides (2.9 g, 90 % purity). Solvent-solvent partition of celery seed oil gave limonene (87%) and a fraction containing phthalides (49%), which on further fractionation afforded a phthalide-enriched fraction (90%). By conventional silica gel column chromatography, a product rich in phthalides (53-74%) could be obtained. Conclusion : Fractional distillation is shown to be a viable method to process celery seed oil into a phthalide-enriched product with high nutraceutical potential.