Drying of sage (Salvia officinalis L.) inflorescences by intermittent and continuous microwave-convective air combination

Eşturk O., ARSLAN M., Soysal Y., Üremiş İ., Ayhan Z.

RESEARCH ON CROPS, vol.12, no.2, pp.607-615, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 12 Issue: 2
  • Publication Date: 2011
  • Journal Name: RESEARCH ON CROPS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.607-615
  • Erciyes University Affiliated: No


The effect of microwave-convective air (M-CA) drying (continuous and intermittent) and convective air (CA) drying of sage (Salvia officinalis L.) inflorescences on drying kinetics and essential oil content was studied. For M-CA drying, four pulse ratio levels (PR1, PR2, PR3 and PR4) at 25 degrees C drying air temperature were used. The average drying rates were 0.211, 0.105, 0.067 and 0.053 kg H2O/kg DM/min for PR1, PR2, PR3 and PR4, respectively. The experimental data were fitted to nine different moisture ratio (MR) models to describe the drying kinetics under various drying conditions. Page model was found satisfactory to describe the drying curves of sage inflorescences. The total quantity of essential oils of sage inflorescences decreased considerably during M-CA drying, whereas the loss of essential oils was limited during CA drying. Compared to shade drying, two essential oil components, sabinene and p-cymene, were lost during CA drying. On the other hand, in addition to these two, alpha-pinene, campene, beta-pinene, limonene, gamma-terpinene, camphor, bornyl acetate, alpha-copaene, gamma-cadinene, delta-cadinene and caryophyllene oxide were disappeared during M-CA drying. M-CA drying may not be proper technique for drying of sage inflorescences when essential oil content is important.