Content of review 1, reviewed on October 08, 2021
The scope of this review will be important to the researchers working on juices or manufacturers that is planning to use high pressure technology to pasteurize juices. As is also mentioned in the manuscript, enzymatic inactivation is an important fact for the shelf-life of the fresh-like juices.
The recent review/book chapters on the high pressure applications on food enzymes are:
“Effect of High-Pressure Technologies on Enzymes Applied in Food Processing”. (http://dx.doi.org/10.5772/66629). This book chapter contains a subtitle “Effect of HIP and HPH on fruit and vegetable enzymes”. Under this subtitle, a short coverage of the subject was given. (*high isostatic pressure (HIP) and high pressure homogenization (HPH))
The other review in the literature is “High-pressure treatments for better quality clean-label juices and beverages: Overview and advances”. (https://doi.org/10.1016/j.lwt.2021.111828). That review article has focused on effect of high hidrostatic pressure on structural components and functional quality of juice and beverages specifing on bioactive components and enzymes.
The third review on this topic is “High-Pressure Inactivation of Enzymes: A Review on Its Recent Applications on Fruit Purees and Juices”. (doi: 10.1111/1541-4337.12071). That review deals with the enzymes too. It reviews the effects of HPP on enzymes in fruit purees and juices, enzymatic action on those products, mechanism of enzyme inactivation during high pressure, their inactivation kinetics, and several intrinsic and extrinsic factors.
The content of the submitted review has common points with the third review. However, the third review is mostly focused on the inactivation kinetics. However, the submitted study deals with the reasons of the inactivation by taking the food structure and process parameters into account. Therefore, the submitted study has an originality.
Authors successfully represented the most relevant recent advances on the use of HPP to inactivate enzymes that reduce the quality of juices during storage. The organization of manuscript incl. tables and figures are reader-friendly. The results obtained in the reviewed studies were given under a sequence. However, in my opinion there are some points (stated below) that will be added to be complementary to the Readers who need specific information on enzymes.
Please read below for the revision of following points. Please also see the uploaded pdf.
L 60: The Readers may have interest in any study concerning the relation between the enzymatic inactivation and cell-wall integrity (by imaging instruments). Please add if there is any.
L 62: please indicate if you mean "cell wall-degrading" enzymes.
L 101: As is known, HPP is a non-thermal treatment however, a temperature rise is possible in HPP treatments. Please clarify the role of temperature rise in HPP-applied media on the inactivation of enzymes by HPP.
L 168: Effect of pressurization on the PPO and POD was well discussed for cloudy apple juice. Please indicate if the effect of HPP changes when the juice is cloudy or clear (if there is a related study in the literature). In line with this, please also clarify the role of high / low total soluble solid content of HPP-applied beverage on the inactivation of enzymes by HPP. In my opinion, this is important for the turbid juice, pulp added juice or clear juice producers to decide on use of HPP.
L 359: In my opinion, effect of pH on the enzymatic inactivation via HPP was not discussed deeply in the manuscript.
Source
© 2021 the Reviewer.
Content of review 2, reviewed on November 11, 2021
None of my previous comments were considered in the revision of the manuscript.
Source
© 2021 the Reviewer.
References
Ume, R., Afeera, A., Rehan, A., Muhammad, M. G., Xin-An, Z., Abdul, R., Muhammad, A. R. 2022. Impact of high-pressure treatments on enzyme activity of fruit-based beverages: an overview. International Journal of Food Science & Technology.
