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Extraction of bio‐active compounds has become very important as these compounds show various characteristics which are beneficial to health, such as antioxidant, anti‐carcinogenic and antimicrobial properties. High pressure extraction (HPE) can be included among the recent and novel methods for extracting bioactive compounds from natural materials. The high pressure is applied to stimulate various phenomena (such as transition of phase from one form to another, change in reaction dynamics, change in molecular structure, etc.) which induces a reaction in a direction promoting a decrease in volume hence resulting in the enhancement of extraction efficiency. This article presents a comprehensive review of HPE and its applications in various food products and wastes. The review highlights that HPE is potential option for conventional extraction methods to meet the industrial demand. As most of the research has been conducted at laboratory scale level therefore recommendations for scaling up of the HPE process are made to evaluate the performance at commercial levels. Practical applications Extraction is considered to be a vital unit operation in downstream processes. However the conventional methods of extraction have various disadvantages viz. time and solvent consuming, energy deficient, poor extraction, risky to environment. High pressure extraction has a huge potential to partially or fully overcome these disadvantages. This review article presents the working mechanism and principle of HPE, and recent research conducted to evaluate the HPE process of potential bio‐active compounds from various plant and animal sources. HPE has been found to facilitate the recovery of these potential bio‐active compounds in their best natural form. Also it is recommended that HPE could be scaled up to make the extraction process relatively easy and efficient at commercial level.

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Fresh juice of fully ripe tomato was subjected to ohmic heat (OH) treatment (908C for 1 min) and the effectiveness of treatment was compared with conventional hot break (CT) treatment (908C for 5 min). PG (Polygalacturonase) and PME (Pectin methyl esterase) enzyme inactivation achieved by the OH (1 min.) was similar as compared to CT of 5 min. During the kinetic analysis it was observed that the inactivation of PME & PG enzyme and degradation of ascorbic acid followed first order trend in ohmic as well as conventional treatment of tomato juice, however total color change (DE) was found to follow least-squares non-linear parameter algorithm behavior. Thermal treatments leads to the increased release of phyto-chemicals from the matrix which results in a significant (p<0.01) increase in lycopene content during the early phases of the treatments. The Paste (2860.5 8Brix) obtained after pre-treatment was analyzed for lycopene, ascorbic acid content and apparent viscosity and color. OH Paste was found more viscous than CT treatment with maximum viscosity of 2.333103 mPa-s. The color of OH treated paste was bright red as compared to CT treatment, however the lycopene and ascorbic acid content of paste were found similar in OH and CT. Based on results of present study it is concluded that the ohmic treatment may be applied as an efficient alternative to the conventional method of enzyme inactivation in tomato juice. K E Y W O R D Scolor, enzyme inactivation, kinetics, ohmic heating, tomato juice J Food Process Eng. 2017;40:e12464.