Effect of Blanching Time and Sulphur Dioxide Fumigation on Physical Chemical and Sensory Quality of Dried Green Peppercorns (Piper nigrum Linn.)

Abstract

The objectives of this research were to study the effects of blanching time and sulphur dioxide (SO₂) fumigation on physical, chemical and sensory quality of dried green peppercorns (Piper nigrum Linn.). A completely randomized design (CRD) was used to study four levels of blanching time which were 3, 5, 7 and 9 min. Non-blanched peppercorns served as a control. Then, threes levels of sulphur dioxide (SO₂) fumigation which were 15, 20 and 25 cm³ and drying at 50ºC for 24 h were studied. The results showed that increase the blanching time enhanced the lightness (L*), greenness (a*), %shrinkage and piperine content, but a significantly decreased (p≤0.05) in %yields, bulk density and polyphenol oxidase (PPO) activities. After SO₂ fumigation caused an increase in L* value, but a decrease in a* value. Increasing the amount of SO₂ had no significant difference (p>0.05) on the L*, a*, %yields, %shrinkage and piperine content. The residue of SO₂ significantly increased (p≤0.05) while PPO activities decreased. The results of sensory evaluation from Pad-cha-pla revealed that the liking score of flavor, pungency, taste and overall liking of dried green peppercorns were not significantly different from fresh green peppercorns (p>0.05). Therefore, the results from this study demonstrated that 7 min of blanching and 15 cm³ of SO₂ fumigation could maintain the quality of dried green peppercorns with consumer acceptability. Finally, dried green peppercorns were safe for consumption, according to the standards of Codex Alimentarius (CXS 326-2017)