ENHANCING DRYING EFFICIENCY FOR IMPROVING THE QUALITY OF TERMINALIA CHEBULA RETZ.: IMPACT OF PRE-TREATMENTS

Abstract

Terminalia chebula Retz. (Harar) is an important medicinal fruit, known for its antioxidant and phenolic constituents. But due to the high moisture content and hygroscopic nature of the fruits, drying techniques are required for retention of bioactives, superior quality and microbial safety and prolonged storage.

The fruits were taken as whole and sliced and were treated with salt roasting, hot water blanching, sulphur fumigation, and dipping in sodium hydroxide and ethyl oleate. After pre-treatments, whole and sliced fruits were tray and solar dried and were utilized for evaluating physicochemical, antioxidant, and sensory properties.

Among drying methods, whole and slice fruits got dehydrated in 22-44 hours under controlled thermal exposure i.e., in tray drying compared to 38-76 hours over solar drying. Whole fruits (T₁₀) dipped in ethyl oleate dried rapidly due to increased microscopic pores in cuticle, allowing rapid diffusion of moisture and retained 445.26 mg/100 g phenolics, 17.03 mg/100 g ascorbic acid and 93.96% antioxidants. For evaluating the storage stability, fruits packed in aluminium pouches recorded 65% equilibrium relative humidity (ERH), indicating aluminium as a barrier to oxygen, light and moisture.

Ethyl oleate (EO) breaks the waxy cuticle and help moisture to remove rapidly in mechanical tray drying. Hermetic packaging also keeps the product safe from microbial and insect attack as well as prevents degradation of pigments, making the product suitable for prolonged storage. Further, studies are required to provide mechanistic validation for the industrial production of high-quality medicinal fruits for food and pharmaceutical sectors.