Effect of temperature on aromatic compound and sensory evaluation
The 2 ACPy content and mean sensory scores for different quality attributes of dried leaves are presented in Table 3. The retention of 2ACPy content in samples dried by heat pump at lower temperature of 35 °C was significantly higher than that dried in hot air dryer at 45 °C. The sensory attributes were almost same for aromatic rice and non aromatic rice with fresh leaves. The aroma and colour of low temperature dried samples were better as compared to hot air and shade dried samples. So this sample had better overall acceptability in comparison to shade dried samples. Though the average ambient temperature for shade drying was less than 35 °C (range 24–38 °C), the temperature values fluctuated round the clock throughout the drying period. At times it was more than 35 °C while during night time it was very less. This thermal stress was probably the reason for which 2 ACPy content got reduced. From the sensory evaluation of dried samples, it was also observed that the samples at lower temperature were preferred products. High temperature drying resulted in decrease in colour, aroma and overall acceptability scores. Samples dried at low temperature appeared slightly lighter in greenness as compared to fresh samples, but the product still looked attractive for use. It is observed that there is significant difference in all these quality parameters achieved at these two different conditions. Since the acceptance of any food product is highly dependent on its quality characteristics, Pandanus leaves without aroma may not fetch any consumer demand. Hence even though the total drying time requirement is more, drying at low temperature may be preferred, for its higher retention of aroma. Alternatively, further reduction in RH along with low temperature may be tried to reduce the total drying time.