Proximate composition, total phenol content and sensory properties of sweet basil (Ocimum basilicum L.) leaves dried using different methods

Abstract

O. basilicum L. samples were sun dried (SUD), solar dried (SOD), shade dried (SD) and oven-dried at 50oC, 60oC, 70oC and 80oC (OV5-OV8, respectively). The samples were evaluated for  proximate composition, polyphenol content, soluble extract, appearance, aroma and general acceptability. Fresh sample served as the control. All the drying methods reduced the moisture levels of the samples to that (?12%) suitable for shelf stability, and led to significantly (p?0.05) higher content of protein, ash and crude fiber in dried samples. The polyphenol content of water extract of dried samples (1.55 mg GAE/100 ml in OV5 to 2.25 mg GAE/100 ml in OV6) were significantly (p?0.05) higher than that of fresh sample (1.13 mg GAE/100 ml) and those of SUD, OV5 and OV8 were significantly (p?0.05) lower than that of OV6. Sample OV6 was higher in water and ethanol soluble extracts (69% and 61%, respectively) than the fresh sample (37%, respectively) and the other dried samples (16-37% and 2-19%, respectively). The scores of the dried samples for appearance (5.15 in SUD to 6.40 in OV6), aroma (5.30 in SUD to 6.85 in OV6) and general acceptability (5.10 in OV5 to 7.25 in OV8) were significantly (p?0.05) lower than those of the fresh sample (8.65, 8.45 and 8.55, respectively). The aroma score for OV6 (6.85) was significantly (p?0.05) higher than the aroma scores for OV5, SUD, SOD and SD (5.30-5.55). Oven drying at 60oC was identified as the best drying method for O. basilicum in terms of aroma and soluble extracts contents.

Keywords: O. basilicum, sensory attributes, drying methods, physicochemical Properties