Assessment of different drying methods on sensory, color and quality attributes of fennel (Foeniculmn vulgare Mill) seeds harvested for chewing purpose

The present investigation was carried out at an experimental farm and post-harvest laboratory of ICAR-NRCSS, Ajmer during 2019-2021. This study aimed to assess the influence of different drying methods on fennel seeds harvested for chewing purposes. Fennel umbels were harvested at 143 days after sowing and 35 days after anthesis and dried under different drying treatments. T1-sun drying, T2-shed drying, T3-hot air oven drying (40oC), T4-hot air oven drying (50oC), T5-shed net (75% shed) drying (on floor), T6-low cost poly solar dryer and T7-drying in shed net (75% shed) with hanging umbels. The findings of the study revealed that the overall acceptability score of dried seeds for chewing purposes was recorded maximum in shed net drying with hanging umbels followed by hot air oven drying (50oC), hot air oven drying (40oC), shed net drying (on the floor), low-cost poly solar drying, shed drying (27±2oC) and least in Sun/Open drying. The chromatic value of seeds dried by different drying approaches was determined and the maximum (L*-lightness) and (a*-greenness, negative) of seeds were measured in shed net drying with hanging umbels and lowest in open drying. The b* value measures yellowness (positive) and resulted highest in the sun/open drying method followed by a low-cost poly solar dryer and least in shed net drying with hanging umbels and shed net (75% shed) drying (on the floor). Among physical attributes of dried seeds, maximum seed length and width were observed in the seeds dried by hot air oven drying (50oC) which was statistically at par with drying in shed net (75% shed) with hanging umbels. The highest seed length/width and seed index (test weight) were observed in seeds dried in a shed net (75% shed) with hanging umbels which was statistically at par with shed net (75% shed) drying (on the floor) and lowest in low-cost poly solar dryer and sun/open drying. Seed oil content was significantly affected by drying methods and maximum total oil &essential oil content was determined in hot air oven drying (50oC) followed by shed net (75% shed) with hanging umbels whereas, minimum in low-cost poly solar dryer followed by sun/open drying. Total soluble solids (TSS) measured highest in seeds dried in shed net (75% shed) with hanging umbels however, least in sun/open drying. From the study, it was suggested that to obtain better quality fennel seeds, harvested for chewing purposes could be dried in a shed net (75% shed) with hanging umbels and hot air oven drying (50oC).