Hot air convective drying of small cardamom (Elettaria cardamomum Maton): Evaluation of drying, color, and aroma kinetics

Abstract Effect of temperatures (40, 50, and 60 ° C) on quality attributes of small cardamom ( Elettaria cardamomum Maton) during hot air convective (HAC) drying was investigated. Kinetics of moisture, color and aroma during the HAC drying were analyzed. Among seven 2‐ and 3‐term exponential models, the Logistic model was best‐fitted to the drying data. Moisture transfer rates were found out to be 1.62 × 10 −8 , 2.51 × 10 −8 , and 3.64 × 10 −8 m 2 s −1 at 40, 50, and 60 ° C, respectively, and the activation energy of diffusion was 34.96 kJ mol −1 . When surface color ( L * , a * , and b * ) and aroma (essential oil yield) were considered as another two quality criteria during the drying of cardamom capsules, samples dried at 50°C was observed to be the best. With drying time, the value of L * decreased, a * value increased, and b * value of cardamom samples increased. Weibull model yielded the higher correlation coefficient between the predicted and the experimental data of color parameters ( L * and a * ) whereas the Zero‐order model was fitted well for b * values for the entire temperature range. Aroma calculated as essential oil yield (% dry basis) increased with drying time due to the release of a large number of volatile components during the drying. Practical Application Small cardamom so far is known to have best among the spices in terms of quality. Although India is among the largest consumer and producer of cardamom, cardamom growers adopt the age‐old processing practices. Furthermore, there is the absence of systematic study and scientific understanding in the existing practice of cardamom drying. The existing design and development of a dryer suitable for cardamom capsules are highly dependent on moisture, color, and aroma profile during drying. Studying drying kinetics along with postprocessing quality evaluation such as color and aroma would support as preliminary information for the development of suitable dryers for optimum retention of color and aroma of cardamom capsules during the drying.