Impact of instant controlled pressure drop on phenolic compounds extraction from pomegranate peel

• ICPD was successfully applied to improve and reduce mass transfer resistance in pomegranate peel extraction.
• Extraction of phenolic compounds from ICPD treated peels was carried out at nearly 20% higher efficiency.
• The results showed direct correlation between TPC and antioxidant activity of the pomegranate peel extract.
• A single-cycle ICPD was sufficient to achieve to the best extraction efficiency.

In this research work, instant controlled pressure drop process (ICPD) was used as a texturing pretreatment to enhance extraction efficiency of phenolic compounds from pomegranate peel. Response surface methodology (RSM) was used to optimize ICPD. Experiments were carried out at steam pressures from 1 to 3 bar, steam exposure time from 10 to 60 s and number of pressure drop cycles from 1 to 5. The textured samples were extracted by 60% (v/v) methanol solution and the best operating conditions for ICPD were determined to be at 3 bar, 60 s and 1 cycle. In comparison with un-textured samples, total phenolic content (TPC) and antioxidant activity as inhibition percent were increased from 38.77 to 46.02 mg GA/g dry basis, and from 62.10 to 74.12%, respectively. Scanning electron microscopy (SEM) of the treated peel illustrated remarkable modification in the texture. Results showed a linear relationship between TPC and antioxidant activity of the textured pomegranate peel.Industrial relevanceIncreasing valuable compounds extraction efficiencies and achieving higher qualities are some of most important goals in food industry. Extraction of total phenols and antioxidants from natural resources and using them in different food products formulations is an interesting research area. This paper shows an efficient way for texturing pomegranate peel to enhance extraction yield of total phenols and antioxidants.