Physicochemical Quality, Polyphenol Profiles, and Postharvest Performance of Florida Pearl® ‘FL 16.78-109’ White Strawberries Compared to the Red Cultivar ‘Florida Brilliance’â€
Round 1
Reviewer 1 Report
The manuscript entitled "Physicochemical Quality, Polyphenol Profiles, and Postharvest Performance of White Strawberries Florida Pearl® ‘FL 16.78-109’ Compared to the Red Cultivar ‘Florida Brilliance’" is a good work, I recommend the manuscript for consideration after some revisions. My comments are as follows;
1. The abstract must contain the details of quantitative determination of total polyphenols and flavonoids
2. The introduction is well-written, especially about the chemistry of the strawberry. However, I recommend to include a detailed paragraph on the pharmacological benefits as a functional food
3. In table 2, the details are not represented as mean and standard deviation (I hope the assays were carried out in different replica)
4. The quality of LC chromatogram must improved. The figure is not clear. (The labels are not clear)
5. Table 3, table 4 and table 5 should also represented as mean and standard deviation
6.
Author Response
Reviewer #1
The manuscript entitled "Physicochemical Quality, Polyphenol Profiles, and Postharvest Performance of White Strawberries Florida Pearl® ‘FL 16.78-109’ Compared to the Red Cultivar ‘Florida Brilliance’" is a good work, I recommend the manuscript for consideration after some revisions. My comments are as follows;
- The abstract must contain the details of quantitative determination of total polyphenols and flavonoids
RE: Although we agree that such details are important, they would increase the length of the abstract to more than 200 words (per the authors' guidelines: “The abstract should be a total of about 200 words maximum”).
- The introduction is well-written, especially about the chemistry of the strawberry. However, I recommend to include a detailed paragraph on the pharmacological benefits as a functional food
RE: We appreciate the suggestion and agree that the pharmacological benefits of strawberry fruit are important, but we believe that such information would fall outside the main scope of the study and would increase the length of the manuscript.
- In table 2, the details are not represented as mean and standard deviation (I hope the assays were carried out in different replica)
RE: Standard errors were added after each mean. The assay was carried out in triplicate. The following information was added to the table footnote: “Means are averages of three harvests per cultivar; n = 3 harvests x 3 replicates of 15 strawberries each”.
- The quality of LC chromatogram must improved. The figure is not clear. (The labels are not clear)
RE: We have replaced the chromatograms with higher resolution image files.
- Table 3, table 4 and table 5 should also represented as mean and standard deviation
RE: Standard errors were added after each mean.
Author Response File: 
Author Response.docx
Reviewer 2 Report
1. Introduction
a. The reason for selecting 9 days of cold storage is not clear.
b. The main reason for the comparison is not clear. Just to compare the physicochemical quality and polyphenol profiles of the two strawberries? Why we need to characterize the two strawberries is more important. It could be an objective of the research Please clarify it.
2. Materials and Methods
a. Provides the altitude, latitude, and longitude of the experimental fields for harvesting the two strawberries.
b. For the destructive measurement, the samples used for the test are different for 0 and 9 days after harvesting. How do the authors keep the maturity of the tested samples similar? Since I think the maturity of the samples has a big influence on the character of the strawberry.
3. Results and Discussion
a. Results. It should be Results and Discussion.
b. 5. Conclusions. It should be 4. Conclusion.
c. Revise Figure 8. The quality of the image is very low. It is difficult to read the information displayed in Figure 8.
d. Revise Figure 9. The quality of the image is very low. It is difficult to read the information displayed in Figure 9.
e. Revise Figure 10. The quality of the image is very low. It is difficult to read the information displayed in Figure 10.
f. Revise Figure 11. The quality of the image is very low. It is difficult to read the information displayed in Figure 11.
g. In general, it is difficult to follow the story of the paper (it is quite a long paper). I highly suggested the authors utilize some machine learning tools to extract the most informative part from the available data. For example, by applying a PCA (principal component analysis) for all samples, the readers may soon understand the difference and similarities between the two strawberries. If the two strawberries are highly laid in different clusters, we also can notice the reason why the two strawberries are different. The loading map of variables may tell soon the readers to understand the points.
Author Response
Reviewer #2
1. Introduction
a. The reason for selecting 9 days of cold storage is not clear.
RE: After 9 days of storage under the experimental conditions used in the study, strawberries started to develop mold, and thus we terminated the experiment. For clarification, we have added a sentence in M&M – Storage Conditions.
2.3. Storage Conditions
As reported previously, optimum storage conditions for strawberries are temperatures close to 1°C with high relative humidity (RH) [25]. Therefore, strawberry samples were stored at 1 ± 0.2°C and 85.0 ± 0.5% RH (VPD = 0.23 KPa) inside temperature- and RH-controlled chambers (Forma Environmental Chambers Model 3940 series, Thermo Electron Corporation, Ohio, USA). The experiments were terminated after 9 days of storage when the fruit started to show signs of decay. The temperature and relative humidity (RH) were monitored throughout the study using HOBO® brand U12 data loggers (Onset Computer Corporation, Pocasset, MA, USA), which records within an accuracy of +/- 0.35 °C. The RH was monitored using HOBO® brand U12 data loggers (Onset Computer Corporation, Pocasset, MA, USA), which records within an accuracy of ± 2.5% from 10 to 90% RH
b. The main reason for the comparison is not clear. Just to compare the physicochemical quality and polyphenol profiles of the two strawberries? Why we need to characterize the two strawberries is more important. It could be an objective of the research Please clarify it.
RE: As stated in the Introduction section, the main reason for the comparison was to obtain more data on the postharvest overall quality of white-fruited strawberries.
“This study aimed to characterize and compare the overall quality of the white-fruited strawberry Florida Pearl® ‘FL 16.78-109’ against the commercial, red-fruited strawberry ‘Florida Brilliance’ at harvest and postharvest. To accomplish this objective, the two strawberry cultivars were harvested simultaneously in January, February, and March, during the 2021 strawberry season. Analytical color and texture, weight loss, total and individual sugars, ascorbic acid, phenolic and anthocyanin contents, and individual polyphenols were measured at harvest and after nine days at 1°C. This is the first study characterizing and comparing the physicochemical quality and polyphenol profiles of the white-fruited Florida Pearl® ‘FL 16.78-109’ strawberry against the commercial red strawberry cultivar ‘Florida Brilliance’ at harvest and after cold storage.”
2. Materials and Methods
a. Provides the altitude, latitude, and longitude of the experimental fields for harvesting the two strawberries.
RE: Added to M&M section.
2.1. Plant Material
The two strawberry cultivars used in this study were the white Florida Pearl® ‘FL 16.78-109’ and red ‘Florida Brilliance’ (hereafter referred to as Pearl and Brilliance, respectively). Both cultivars were harvested from experimental fields at the University of Florida Gulf Coast Research and Education Center in Wimauma, Florida, USA (27.76°N; 82.23°N; 39.95 m). Strawberries were harvested during the 2021 season on January 18, February 10, and March 1.
b. For the destructive measurement, the samples used for the test are different for 0 and 9 days after harvesting. How do the authors keep the maturity of the tested samples similar? Since I think the maturity of the samples has a big influence on the character of the strawberry.
RE: We agree that the maturity of fruit at harvest significantly influences the overall quality and shelf life of strawberries during postharvest. For that reason, the strawberries used in the experiments were carefully selected from a large pool where color was used as selection criteria. Using a large initial sample helps select fruit with a similar ripeness stage and thus reduces maturity effects. Please see M&M – Plant material.
“Two flats of Brilliance containing ≈ 300 strawberries each and one flat of Pearl containing ≈ 120 strawberries were harvested in January. Two flats of Brilliance and Pearl, each containing ≈ 300 strawberries, were harvested in February and March.”
3. Results and Discussion
a. Results. It should be Results and Discussion.
RE: Corrected.
b. 5. Conclusions. It should be 4. Conclusion.
RE: Several conclusions were drawn based on the results; therefore, we want to keep them as “Conclusions.”
c. Revise Figure 8. The quality of the image is very low. It is difficult to read the information displayed in Figure 8.
RE: We have replaced the chromatograms with higher resolution image files.
d. Revise Figure 9. The quality of the image is very low. It is difficult to read the information displayed in Figure 9.
RE: We have replaced the chromatograms with higher resolution image files.
e. Revise Figure 10. The quality of the image is very low. It is difficult to read the information displayed in Figure 10.
RE: We have replaced the chromatograms with higher resolution image files.
f. Revise Figure 11. The quality of the image is very low. It is difficult to read the information displayed in Figure 11.
RE: We have replaced the chromatograms with higher resolution image files.
g. In general, it is difficult to follow the story of the paper (it is quite a long paper). I highly suggested the authors utilize some machine learning tools to extract the most informative part from the available data. For example, by applying a PCA (principal component analysis) for all samples, the readers may soon understand the difference and similarities between the two strawberries. If the two strawberries are highly laid in different clusters, we also can notice the reason why the two strawberries are different. The loading map of variables may tell soon the readers to understand the points.
RE: We agree that the manuscript is long, but the story is simple. We have compared the overall postharvest quality of white versus red strawberry cultivars because there is a lack of information regarding white-fruited strawberries. We somehow agree with the suggestion of using PCA, but we would like to keep the data organized as is because it clearly shows the distinct characteristics of the two strawberry cultivars without adding further analysis.
Author Response File: Author Response.docx
Reviewer 3 Report
The manuscript is well organized, results are clearly presented and references are up-to-date.
There are some minor issues that should be addressed by authors.
Specific comments and suggestions are given below.
Abstract: Please add temperature and humidity of cold storage. at the end, add one sentence for the main conclusion.
Lines 108-114, 129-147: Please change the text to decrease similarity with Ref. 46.
Conclusion: Please add the sentence for the overall conclusion.
Author Response
Reviewer #3
The manuscript is well organized, results are clearly presented and references are up-to-date.
There are some minor issues that should be addressed by authors.
Specific comments and suggestions are given below.
Abstract: Please add temperature and humidity of cold storage. at the end, add one sentence for the main conclusion.
RE: Added.
Abstract: White-fruited strawberry cultivars have recently become popular due to their exotic appearance and flavor, but more is needed to know about their overall quality and postharvest performance. The objective of this study was to characterize and compare the overall quality of the white-fruited strawberry Florida Pearl® ‘FL 16.78-109’ against the commercial, red-fruited strawberry ‘Florida Brilliance’ at harvest and during cold storage (1 °C). Results showed that harvest date and weather conditions contributed to significant differences in fruit quality, regardless of the cultivar. However, Pearl was softer at harvest and had lower total phenolic and anthocyanin contents but was less acidic and had higher total sugars and ascorbic acid contents than Brilliance. Pearl major polyphenols were kaempferol 3-glucoside, quercetin 3-glucoside, quercetin, and gallic acid, while for Brilliance epicatechin, pelargonidin, pelargonidin 3-glucoside, and ferulic acid, were the major polyphenol compounds identified. After cold storage, Pearl lost less weight than Brilliance and showed a less dramatic decline in individual polyphenols. Pearl and Brilliance anthocyanins and phenolic acids were the polyphenol groups most affected by cold storage because they showed the highest decline from harvest to the end of storage. Cold storage also had different effects on other polyphenols, but the effect was cultivar dependent. Overall, white strawberries have a unique appearance, are sweet, have an excellent bioactive profile, and can maintain good postharvest quality.
Lines 108-114, 129-147: Please change the text to decrease similarity with Ref. 46.
RE: Reference 46 is a study conducted in our laboratory, hence the similarities between the two studies regarding description of experimental procedures.
46. Kelly, K., et al., Sensory and Physicochemical Quality, Residual Fungicide Levels and Microbial Load in ‘Florida Radiance’ Strawberries from Different Disease Control Treatments Exposed to Simulated Supply Chain Conditions. Foods, 2021. 10(7): p. 1442.
Conclusion: Please add the sentence for the overall conclusion.
RE: Added.
“Overall, white-fruited strawberries have a unique appearance, and compared to red-fruited strawberries, they are sweeter, have an excellent bioactive profile, and can maintain a good quality profile during cold storage.”
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
There are comments yet to be addressed. Recommend to complete the revision
Author Response
We have addressed all comments listed 1-5. I can see point 6, but I cannot see any comments for that point.
Reviewer 2 Report
The revision is acceptable.
