Effects of High-Pressure Processing (HPP) on Antioxidant Vitamins (A, C, and E) and Antioxidant Activity in Fruit and Vegetable Preparations: A Review
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsOverall, the manuscript “Effects of High Pressure Processing (HPP) on Antioxidant Vitamins (A, C and E) and Antioxidant Activity in Fruit and Vegetable Preparations: A Review” which briefly elaborates the principle of high-pressure technology and its development history, demonstrating its feasibility as a green and sustainable preservation method. However, there are several points should be clarified and solved. We hope the authors could be well revised and further improve the manuscript:
1. Some of the references cited in this paper are rather dated (e.g., 1999), lacking recent literature, or merely providing background references to earlier key studies?
2. Is the mechanism underlying changes in antioxidant activity associated with vitamin retention, polyphenol release, or alterations in enzyme activity? A systematic review is recommended.
3. Are the label examples in Figure 5 representative? Moreover, the image clarity is poor.
4. The tables in the text are not three-line tables; it is recommended that they be changed to three-line tables.
5. Has consideration been given to research findings from different geographical regions, such as Asia, the Americas, and Europe? Does the current literature possess global representativeness?
6. Table 1 is voluminous and informative, but it only describes trends textually, lacking quantitative synthesis. Readers find it difficult to visually assess the holistic efficacy of HPP across different products.
7. The application of artificial intelligence in food processing is extensive. Could artificial intelligence be integrated to assess nutrient losses during high-pressure processing? Could you refine Part 3 in relation to this content? For instance, the principles discussed in recent reviews on advanced imaging and spectroscopy, which highlight the role of AI in assessing nutritional components, could be directly applicable.
Author Response
Thanks for the valuable and accurate comments reported by both reviewers. We have revised the manuscript following their recommendations and suggestions to improve this paper. We have answered point by point all the recommendations.
Round 1.
Comment 1: Some of the references cited in this paper are rather dated (e.g., 1999), lacking recent literature, or merely providing background references to earlier key studies?
Response 1: Thanks for this comment. We agree with the reviewer, but our intention was to show that the first work (key study) was published by Hite more than 125 years ago (1899), when High Pressure Processing was first applied to food, before the industrial implementation of this technology at a commercial level (1990). furthermore, pressurization principles have been known for a long time.
Nevertheless, we have updated and replaced several references not recent, cited now with numbers 1, 2, 3, 6, 97, 98 and 99:
- Téllez et al. 2001; replaced by [1] Demazeau, G. and Rivalain, N. High hydrostatic pressure and biology: a brief history. Appl Microbiol Biotech 2011, 89 (5), 1305-1314.
- Hite, 1899; replaced by [2] Thakur Thakur, B.R., and Nelson, P.E. High pressure processing and preservation of foods. Food Rev Int 1998, 14(4), 427–447.
- Balasubramaniam, 2003; replaced by [3] Balasubramaniam V.M.; Martínez-Monteagudo, S.I.; Gupta, R. Principles and application of High Pressure-Based Technologies in the food industry. Annu Rev Food Sci Technol 2015, 6, 19.1–19.28.
- Datta and Deeth, 1999; replaced by cited reference [6]: Song, Q.; Li, R.; Song, X.; Clausen, M.P.; Orlien, V.; Giacalone, D. The effect of high-pressure processing on sensory quality and consumer acceptability of fruit juices and smoothies: A review. Food Res Int 2022, 157, 111250.
- Rodríguez-Comesaña et al., 2002; replaced by 3 cites to include data from other markets:
[97] Aykas, D.P.; Rodriguez-Saona, L. What’s in Your Fruit Juice?-Rapid Quality Screening Based on Infrared (FT-IR) Spectroscopy. Appl Sci 2024, 14, 1654.
[98] Da Silva-Mojón, L.; Pérez-Lamela, C.; Falqué-López, E. Smoothies Marketed in Spain: Are They Complying with Labeling Legislation? Nutrients. 2023, 15, 4426.
[99] Nishijima, C.; Sato, Y.; Chiba, T. Nutrient Intake from Voluntary Fortified Foods and Dietary Supplements in Japanese Consumers: A Cross-Sectional Online Survey. Nutrients. 2023, 15, 3093.
Please, note that this latter reference related to Spanish market is signed by Pérez Lamela, author of this manuscript. And I must confess that is not my intention to quote myself. So, the editor should decide if is convenient or not to include this reference.
Comment 2: Is the mechanism underlying changes in antioxidant activity associated with vitamin retention, polyphenol release, or alterations in enzyme activity? A systematic review is recommended
Response 2: Thank you for this observation. What you suggest is very interesting. Considering the literature here reviewed, it is not easy to generally associate changes in antioxidant activity with contents of vitamin, polyphenol and enzymes activity during HPP processing. The reason is that the studies reviewed were heterogeneous and varied in several aspects: fruit derivatives (juice, smoothie, puree…), plant species and varieties (strawberry, orange, apple…), HPP treatment conditions (200-600 MPa; 0.5-15 min; 15-60ºC), methods to determining all quality parameters, e.g.: DPPH, ABTS, FRAP, TPC (for antioxidant activity), volumetric, spectrophotometric or chromatographic assays (for vitamin C); compounds measured in each method (ascorbic acid and/or dehydroascorbic acid for vitamin C; carotene and/or carotenoids for vitamin A). The reviewed studies do not usually provide the correlation between parameters (vitamins and antioxidant activity) and several articles do not analyze them all simultaneously.
This paragraph is now included in the new version of the manuscript (lines 644-655).
Concerning to this comment, it is interesting to highlight that polyphenol release can be improved by HPP, but this behavior is more related to HPP when is used to extract components not to process food for stabilization purposes.
Note that enzymes were not reviewed in this work.
Looking at results from Table 1, it can be said that: Overall, studies that determine the effects of pressurization on vitamins (especially ascorbic acid) and antioxidant activity simultaneously indicate that both are better retained with this type of treatment than with heat pasteurization (see lines 656-659 in the new version).
Comment 3: Are the label examples in Figure 5 representative? Moreover, the image clarity is poor.
Response 3: The label examples were taken from Spanish supermarkets juices and smoothies and from internet web pages. It was quite difficult for us to obtain F&V preparations from American and Asian market unless the products are not sold on-line. The image is now enlarged to improve readability and to better visualize the different mentions such as “cold pressed”, “pressurized”, “under pressure”, HPP; that are confuse for the potential consumers. Two bottles (copa trademark from Portugal, numbered 7 and Suja with number 7, in the Figure 5) were replaced by other two bottles. We have found more examples of pressurized products commercial, and all their mentions are included in this figure. So, we consider that the label examples shown in the Figure 5 are representative.
Comment 4: The tables in the text are not three-line tables; it is recommended that they be changed to three-line tables.
Response 4: Thanks for the suggestion. The tables are now modified in the new version and formatted to three-line tables.
Comment 5: Has consideration been given to research findings from different geographical regions, such as Asia, the Americas, and Europe? Does the current literature possess global representativeness?
Response 5: Thank you for your comment. The articles were reviewed using the Scopus database, with ‘high pressure processing’ as the main search term, without applying any geographical restrictions. Therefore, we consider that the information presented here is representative of global markets for HPP-processed foods as the studies reviewed come from around the world. Moreover, we have added 3 additional studies (see Response 1) from Spain, USA and Japan.
Comment 6: Table 1 is voluminous and informative, but it only describes trends textually, lacking quantitative synthesis. Readers find it difficult to visually assess the holistic efficacy of HPP across different products.
Response 6: Thank you for this observation. Sentences related to main results extracted from Table 1 were already included in the old version (see lines 578-591 and 626-632). And new paragraphs were added in the new version (lines 644-659):
“In summary, all the studies reviewed (included in Table 1) were heterogeneous and varied in several aspects: fruit derivatives (juice, smoothie, puree…), plant species and varieties (strawberry, orange, apple…), HPP treatment conditions (200-600 MPa; 0.5-15 min; 15-60ºC), methods to determining all quality parameters, e.g.: DPPH, ABTS, FRAP, TPC (for antioxidant activity), volumetric, spectrophotometric or chromatographic assays (for vitamin C); compounds measured in each method (ascorbic acid and/or dehydroascorbic acid for vitamin C; carotene and/or carotenoids for vitamin A).
On the other hand, the reviewed studies often lack an analysis of the correlation between parameters such as vitamin content and antioxidant activity, and several of them do not evaluate all these components simultaneously. As a result, it is difficult to draw general conclusions applicable to different fruits and vegetables (F&V) and their associated compounds.
Nevertheless, based on the results presented in Table 1, it can be observed that, overall, studies assessing the effects of pressurization on both vitamin levels (particularly ascorbic acid) and antioxidant activity tend to report better retention of these compounds compared to conventional heat pasteurization (see Table 2)”.
Comment 7: The application of artificial intelligence in food processing is extensive. Could artificial intelligence be integrated to assess nutrient losses during high-pressure processing? Could you refine Part 3 in relation to this content? For instance, the principles discussed in recent reviews on advanced imaging and spectroscopy, which highlight the role of AI in assessing nutritional components, could be directly applicable.
Response 7: Thank you for this idea.
We have not enough experience to evaluate nutrient loss by using AI, in the way the reviewer suggest.
So, we checked carefully and contrasted the studies, one by one, all the modifications caused by these technologies (HPP, PATP and TP) on antioxidant compounds and antioxidant activity.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsI have reviewed the article: Effects of High Pressure Processing (HPP) on Antioxidant Vita-2 mins (A, C and E) and Antioxidant Activity in Fruit and Vegeta-3 ble Preparations: A Review
The article represents a valuable contribution to the specialized literature, offering a comprehensive synthesis of the effects of High Pressure Processing (HPP) on antioxidant vitamins in fruit and vegetable preparations.
Abstract doesn’t clearly specify the review methodology.
Please be consistent with the abbreviations used in the article (HPP/HHP). Also, if an abbreviation is already explained, there is no need to reexplain it each time in the text. Please explain abbreviations used in table underneath each table.
I have observed that certain ideas appear several times in the paper (see first 2 chapters). Please exclude redundancy.
Methods chapter should be included. Is it a systematic review or a narrative review? The manuscript does not specify: the number of reviewers and screening stages; how selection bias was addressed; which risk-of-bias tool was used (e.g., RoB 2, ROBINS-I, QUADAS-2); the MeSH terms applied to each database search; the inter-rater agreement statistic (e.g., kappa). Consider adding a section focused on methodological limitations.
Figure 1 mentions studies published in the last 15 years though study evaluated only the last 8 years.
Vitamin E data are little and inconsistent – it should be commented.
Regulatory recommendations should be inserted and commented on. A comparison between FDA, EFSA and other authorities recommendation is useful.
Are there any recommendations for future research or industry implementation of results?
The reference formatting should follow the MDPI guidelines consistently.
Figure 5 (product labels) does not meet academic standards. It should be removed or replaced by an appropriate one.
Author Response
Round 1:
The article represents a valuable contribution to the specialized literature, offering a comprehensive synthesis of the effects of High Pressure Processing (HPP) on antioxidant vitamins in fruit and vegetable preparations.
Thanks to the reviewer for the hard work in conducting this revision. Your valuable comments will help us improve the manuscript. Please, see our answers to the reviewers´ recommendations, numbered from first to last.
Comment 1: Abstract doesn’t clearly specify the review methodology.
Response 1: Thanks for this comment. We agree the reviewer; therefore, a sentence including the review methodology was added in the abstract (see lines 15-16 in the new version of the manuscript).
Comment 2: Please be consistent with the abbreviations used in the article (HPP/HHP). Also, if an abbreviation is already explained, there is no need to reexplain it each time in the text. Please explain abbreviations used in table underneath each table.
Response 2: Thanks for this observation. HHP abbreviation has now been replaced by HPP along the whole manuscript. The abbreviations used in the tables are now described in the new version (lines 571, 572 and 651).
Comment 3: I have observed that certain ideas appear several times in the paper (see first 2 chapters). Please exclude redundancy.
Response 3: Thank you for your carefully revision. We have revised repeated ideas in this 2 first sections and delete them. See in the new version the lines 71, 81, 99-101, 188, 190-191 (this sentence is not related to F&V preparations), 193-194, 238-239, 268-269) and 590-591 (in subsection 3.1).
Comment 4: Methods chapter should be included. Is it a systematic review or a narrative review? The manuscript does not specify: the number of reviewers and screening stages; how selection bias was addressed; which risk-of-bias tool was used (e.g., RoB 2, ROBINS-I, QUADAS-2); the MeSH terms applied to each database search; the inter-rater agreement statistic (e.g., kappa). Consider adding a section focused on methodological limitations.
Response 4: Thank you for this very precise comment. It is a mixture of both types of review, it is not entirely narrative, but it is not systematic at all. A new subsection has been added that includes the search methodology in the new manuscript (lines 31 and 103), and the text that reports the criteria for selecting and excluding the reviewed articles is now included in this subsection.
The selection of articles was made by searching the Scopus database for various terms in Article title, Abstract, Keywords using Boolean operators (AND, OR): “High Pressure Processing” OR “High Hydrostatic Pressure” OR “High Pressure Treatment” OR “Pressure Assisted Thermal Processing” OR “High Pressure High Temperature” OR “Non thermal technologies” OR “Novel technologies” OR “Emerging technologies” AND “Fruit derivatives” OR “Fruit preparations” OR “Vegetable preparations” OR puree OR juices OR smoothies OR beverages AND “vitamin A” OR Carotene OR Carotenoids OR “Vitamin C” OR “ascorbic acid” OR “Vitamin E” OR tocopherol OR “antioxidant activity” OR “antioxidant capacity” OR polyphenols. This search resulted in 389 documents (from 2018-2025).
Limitations and exclusion criteria: we have excluded studies that apply other high pressure modalities such as High pressure homogenization, High pressure extraction, High pressure microfluidization, High pressure for hyperbaric storage. We also have excluded works with preparations/beverages that include milk or other ingredients of animal origin in their formulation as well as studies that exclusively examined enzymes, microbiology, virus and the kinetics of vitamins/bioactive compounds degradation.
This explanation is now specified in a new subsection of the manuscript:
2.1 Methodology used to select HPP bibliography (lines 103-124).
Comment 5: Figure 1 mentions studies published in the last 15 years though study evaluated only the last 8 years.
Response 5: Thank you for your comment. We selected the last 8 years because 2018 is the year with almost 500 documents related to HPP/novel technologies (see Figure 1). From this year until 2025, around 400 works complied the searching criteria described in response 4. Selecting earlier years would make this manuscript too long.
Comment 6: Vitamin E data are little and inconsistent – it should be commented.
Response 6: Thank you for this suggestion. The vitamin E content in HPP-processed fruit and vegetables derivatives is relatively low. This vitamin is abundant in vegetable oils, seeds and nuts, in leafy vegetables (spinach, broccoli, lettuce) but not really in fleshy fruits, except avocados. Therefore, studies that include its analysis are very scarce in the last 8 years. In fact, we have found very few articles that mention vitamin E under HPP in F&V preparations (references 105-108), that are now reported in the new version of this manuscript (lines 548-554):
- Barba, F.J.; Esteve, M.J.; Frigola, A. Impact of high-pressure processing on vitamin E (α-, γ-, and δ-tocopherol), vitamin D (cholecalciferol and ergocalciferol), and fatty acid profiles in liquid foods. J Agric Food Chem 2012, 60(14), 3763-3768.
- Zhang, J.; Cheng, J.; Li, Z.; Weng, M.; Zhang, Z.; Tang, X.; Pan, Y. Effects of ultra-high pressure, thermal pasteurization, and ultra-high temperature sterilization on color and nutritional components of freshly-squeezed lettuce juice. Food Chem 2024, 435, 137524.
- Schmidt, M.; Hopfhauer, S.; Schwarzenbolz, U.; Böhm, V. High-Pressure processing and heat sterilization of kale: Impact on extractability, antioxidant capacity and storability of carotenoids and vitamin E. Appl Res 2022, 1, e202200025.
- Ferreira Ferreira Da Silveira, T.; Cristianini, M.; Kuhnle, G.G.; Braga Ribeiro, A.; Teixeira Filho, J.; Teixeira Godoy, H. Anthocyanins, non-anthocyanin phenolics, tocopherols and antioxidant capacity of açaí juice (Euterpe oleracea) as affected by high pressure processing and thermal pasteurization. Inn Food Sci Emerg Technol 2019, 55, 88-96.
Comment 7: Regulatory recommendations should be inserted and commented on. A comparison between FDA, EFSA and other authorities recommendation is useful.
Response 7: Thank you for this comment. Our intention was to review only the properties related to antioxidant compounds. Although legal concerns could be a barrier to exporting and selling pressurized products to other countries, our initial objectives did not cover legal issues. Otherwise, the additional references and length of the manuscript would have made this document too long.
Several pressurized F&V preparations can be acquired from web pages without any legal barrier.
A sentence related to legal issues is now written in Conclusions section (lines 684-686): legal concerns could be a barrier to export and sell pressurized products to other countries, and consumer acceptance with labels advertising the use of this emerging technologies is also a challenge.
Comment 8: Are there any recommendations for future research or industry implementation of results?
Response 8: Researchers would find a labile compound suitable for comparing the effectiveness of HPP treatment with other novel and conventional treatments (pasteurization by heat, by pulsed electric fields, ultrasound, etc.). In this way, the industry could choose the most suitable preservation method for its products, similar to the use of “F” values for heat treatments. Another recommendation is the use of food simulants enriched with labile compounds (e.g., ascorbic acid) to check and compare treatments, avoiding differences in food matrices.
This sentence is now included in the Conclusions section of the new version.
Comment 9: The reference formatting should follow the MDPI guidelines consistently.
Response 9: Thanks for this comment. We have formatted the references considering author guides in the new version and misprints were also corrected.
Comment 10: Figure 5 (product labels) does not meet academic standards. It should be removed or replaced by an appropriate one.
Response 10: Several images were photographed from juices found in Spanish supermarkets and others were taken from websites. Our intention was to highlight the ambiguity that exists for consumers who purchase F&V juices/smoothies between “cold-pressed” and “pressurized” and the difficulty to understand abbreviations such as HPP, written on the food label. Figure 5 details several mentions. We have replaced two images, one with the largest bottle and enlarged the images in this figure to improve the readability of the mentions related to high pressure/cold pressed. We hope it is now meeting academic standards.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThank you for the updated article
