Tamarind seeds: Potential valorisation as coffee substitute-roasting and its characterization

Tamarind seeds, often underutilized, which are rich in phenols and flavonoids and also good source of minerals and amino acids are being explored as a potential coffee substitute through roasting at light, medium, and dark levels. The current study compares tamarind seed brews' (roasted in a rotary oven at 240 °C for 16 min (light), 250 °C for 17 min (medium), and 250 °C for 21 min (dark)) physicochemical, phytochemical, aroma profile, and sensory characteristics with coffee brew. As the roasting intensity increased, there was a decrease in L* , b* , ΔE, chroma, and hue angle (H°), while a* and browning index values were higher in the medium brew. The increase in roasting level also reduced total soluble solids (1.16–0.70 °Brix), titratable acidity (0.14–0.10 %), total phenolic content, and antioxidant activity. The dark roast exhibited the highest pH (6.10), extraction yield (11.63 %), total solid content (15.64 mg/mL), and viscosity (1.62 cP). The caffeine content in the tamarind seeds at different roasting was nil. Aroma profile analysis revealed the presence of furans, pyrazines, pyrroles, aldehydes, and ketones in the brews, which contributed to the aroma of tamarind seed brew similar to coffee brew. Sensory evaluation indicated that the dark tamarind seed brew resembles and comparable to coffee. The PCA biplot of sensory data of coffee and dark brew exhibited higher values for aroma, taste, color, aftertaste and overall acceptability in comparison to light brews, suggesting its potential as a viable coffee substitute.