Improving quality and quantity attributes of grape juice concentrate (molasses) using ohmic heating

  • Hosain DarvishiEmail author
  • Mahmoud Koushesh Saba
  • Nasser Behroozi-Khazaei
  • Himan Nourbakhsh
Original Article


The effect of ohmic heating method (OHM) on quality and quantity attributes of black grape molasses was investigated and compared with the conventional heating method (CHM). Results showed that the samples prepared by OHM had the highest antioxidant activity than CHM. Increasing of voltage gradient had a positive effect on the saving of antioxidant activity. Changes in pH for OHM were lower than CHM. Heating methods had no significant effect on phenol content. Antioxidant capacity and phenol content of treated samples were lower than the fresh sample at the same water content. The titratable acidity of treated samples using CHM was higher than the OHM. The OHM saved about 2.4–7.2-fold of processing time and 6.3-fold of energy consumption than the CHM. Heat generation and electrical conductivity depended on sample moisture content. OHM provides minimal damage to the sensory characteristics. As a final result, the OHM significantly improved the quality and saved the quantity parameters of the grape molasses processing than the CHM.


Conventional heating Phenol content Antioxidant Energy Grape molasses 



Financial support for this research (Research Project No. 4/48202) was provided by University of Kurdistan, Sanandaj, Iran.


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Copyright information

© Association of Food Scientists & Technologists (India) 2019

Authors and Affiliations

  • Hosain Darvishi
    • 1
    Email author
  • Mahmoud Koushesh Saba
    • 2
  • Nasser Behroozi-Khazaei
    • 1
  • Himan Nourbakhsh
    • 3
  1. 1.Department of Biosystems Engineering, Faculty of AgricultureUniversity of KurdistanSanandajIran
  2. 2.Department of Horticultural Science, Faculty of AgricultureUniversity of KurdistanSanandajIran
  3. 3.Department of Food Science and Engineering, Faculty of AgricultureUniversity of KurdistanSanandajIran

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