Sensory Evaluation and Spectra Evolution of Two Kiwifruit Cultivars during Cold Storage

Round 1

Reviewer 1 Report

Comments

 In this paper, ROC analysis was used to evaluated and analyzed the sensory characteristics of the yellow-fleshed variety "Jintao" and the green-fleshed variety "Hayward" during 3-year storage period and whether typical Vis-NIR spectroscopy can be used to determine the optimal cooking period was studied. The content of the paper is simple，logic is unreasonable. It recommends to publish after major review in “Horticulture”. There are some improvements as follows:

1. Maintain consistent font formatting in the main text.

2. The authors should briefly introduce the research background at the beginning of the abstract.

3. In keywords,‘Jintao’and‘Hayward’should be replaced with kiwifruit.

4. In keywords, organoleptic should be replaced with sensory evaluation.

5. In line 12, the storage time for Hayward kiwifruit is 2, 4 and 5 months, but in line 74, it is 2.5, 4.5 and 5.5 months. Please unify the statement.

6. Author should explain in the introduction why‘Jintao’was selected as the experimental material from the yellow kiwifruit variety in the introduction.

7. Author should explain the relationship between sensory evaluation and Vis-NIR spectroscopy in the introduction.

8. Line 94-106, the author should add references to prove the experimental method.

9. In conclusion and discussion, the author should include photos of two kiwifruit during storage.

10. Line 107 and 136, blank lines should be deleted.

11. Author lacked discussion on the experimental results and should add.

12. Literature was published earlier, and the author should add some references from the past five years.

13. In table 3, for Hayward kiwifruit, author chose a storage period of 74, 131, 172 days in 2019, but chose a storage period of 53, 123, 152days in 2021. The author should explain whether different storage periods have an impact on sensory evaluation.

14. In the paper, some images are not clear, please replace them with clear ones.

Some languages need to be changed

Author Response

Dear reviewer

Thank you for your comments. We tried to follow all of them accordingly:

1. Maintain consistent font formatting in the main text.

Corrected through text.

2. The authors should briefly introduce the research background at the beginning of the abstract.

Added in the abstract

3. In keywords,‘Jintao’and‘Hayward’should be replaced with kiwifruit.

Corrected

4. In keywords, organoleptic should be replaced with sensory evaluation.

Corrected

5. In line 12, the storage time for Hayward kiwifruit is 2, 4 and 5 months, but in line 74, it is 2.5, 4.5 and 5.5 months. Please unify the statement.

Corrected in abstract to 2.5, 4.5 and 5.5 months

6. Author should explain in the introduction why‘Jintao’was selected as the experimental material from the yellow kiwifruit variety in the introduction.

Added the explanation:

The ‘Jintao’ cultivar selected at the Wuhan Institute of Botany (WIB), China, was introduced into Europe for evaluation in 1998, and as increased the growing area and interest, since then (Costa et al., 2018).

7. Author should explain the relationship between sensory evaluation and Vis-NIR spectroscopy in the introduction.

Corrected with the introduction of new references:

An obvious option is the use of the visible-near infrared (Vis-NIR) spectroscopy, since it is one of the most successful non-destructive methods for quality assessment of fruits [17,18] and has been applied to assess the sensory attributes of different products such as  apples [19], chicory [20], olive oil [21], cheese [22, 23], coffee [24], grapes [25] and tea [26].

8. Line 94-106, the author should add references to prove the experimental method.

We think it is not necessary, since they are standard and complete described methods.

Nevertheless, we included the standard AOAC (1994), reference.

9. In conclusion and discussion, the author should include photos of two kiwifruit during storage.

We have no good photos to add, but we believe that they are not absolutely necessary.

10. Line 107 and 136, blank lines should be deleted.

Corrected

11. Author lacked discussion on the experimental results and should add.

Discussion was improved

12. Literature was published earlier, and the author should add some references from the past five years.

The earlier references were added due to be the standard methodology. More recent references were also added.

13. In table 3, for Hayward kiwifruit, author chose a storage period of 74, 131, 172 days in 2019, but chose a storage period of 53, 123, 152days in 2021. The author should explain whether different storage periods have an impact on sensory evaluation.

We believe that there is no problem in the analysis, since we are including in it all values measured through storage time in all years.

14. In the paper, some images are not clear, please replace them with clear ones.

Figures were replaced.

15. Comments on the Quality of English Language

Some languages need to be changed

Language was reviewed by an English native colleague

Reviewer 2 Report

 It is a very interesting study. However, some information needs to be defined.

1.The introduction part lacks literature on the correlation between SSC, hardness and refractive index.

2.The specific literature using near infrared spectroscopy to evaluate fruit quality indicators needs to be supplemented.

3.The total number of samples required for the test should be explained in line 58.

4.What is the basis for the selection of storage time of two varieties of kiwifruit in line 73-74 ? Why does Hay-ward kiwifruit take longer to observe ? These need to be detailed.

5.Line 79 should be added to explain the wavelength range of the spectrometer, integration time and other equipment parameters.

6.The ROC analysis method used in the manuscript is an artificial sensory evaluation. Whether it contradicts the content of 40 lines should be explained in detail.

7.The pairwise comparison images in Figure 1 and Figure 2 can be optimized.

8.The link between SSC and the best edible stage needs to be supplemented by references.

9.The materials and methods section lacks relevant pictures.

Author Response

Dear reviewer

Thank you for your comments. We tried to adress acordingly.

 It is a very interesting study. However, some information needs to be defined.

1.The introduction part lacks literature on the correlation between SSC, hardness and refractive index.

It was improved in the introduction

2.The specific literature using near infrared spectroscopy to evaluate fruit quality indicators needs to be supplemented.

Done with added references

An obvious option is the use of the visible-near infrared (Vis-NIR) spectroscopy, since it is one of the most successful non-destructive methods for quality assessment of fruits [17,18] and has been applied to assess the sensory attributes of different products such as  apples [19], chicory [20], olive oil [21], cheese [22, 23], coffee [24], grapes [25] and tea [26].

 3.The total number of samples required for the test should be explained in line 58.

Done with an added reference (Gago 2022)

4.What is the basis for the selection of storage time of two varieties of kiwifruit in line 73-74 ? Why does Hayward kiwifruit take longer to observe ? These need to be detailed.

Explained now in the text

5.Line 79 should be added to explain the wavelength range of the spectrometer, integration time and other equipment parameters.

Corrected:  ….working in the range 345 – 1037 nm, integration time 20 msec and 50 averages,…

And

….working in the range 145 – 1100 nm, integration time 1.2 msec and 50 averages,…

6.The ROC analysis method used in the manuscript is an artificial sensory evaluation. Whether it contradicts the content of 40 lines should be explained in detail.

Sensory evaluation reports in line 40 to the evaluation by consumers, while the ROC is the analysis of the results.

We modified line 40 for better understanding:

Organoleptic evaluation by consumers is a practical and cost-effective method to evaluate the freshness of agricultural products, however the sensory information is affected by personal preferences, experiences and subjective feelings [13]

7.The pairwise comparison images in Figure 1 and Figure 2 can be optimized.

Figures were replaced.

8.The link between SSC and the best edible stage needs to be supplemented by references.

Corrected: …Those two parameters are correlated to SSC (ºBrix) and firmness, respectively [17]…..

9.The materials and methods section lacks relevant pictures.

We did not have pictures, so we tried to improve the section description

Reviewer 3 Report

Paper:

“Sensory Evaluation and Spectra evolution of two Kiwifruit Cultivars During Cold Storage”

by Afonso et al., Horticulturae

General comments:

The purpose of this manuscript was to evaluate whether receiver operating characteristic (ROC) analysis could be a new approach in assessing the optimum eating-ripe phase of fruits. Two cultivars of kiwifruit were evaluated through both sensory evaluation and spectroscopic analysis at different periods of refrigerated storage. Although well written using clear, easy-flowing English, the paper is not ready to be published.

Specific comments:

·         Why was the sensory evaluation carried out independently for the two kiwi cultivars and moreover, why were not the same time intervals chosen?

·         Regarding spectroscopic analysis, can the use of different equipment not affect the final result?

·         The results are on the whole poorly discussed, no distinctive feature of this work appears among the many articles available.

·         Figures 1 and 2 are difficult to read, please give more in-depth comments.

·         It is unclear in the text the correlation between reflectance spectrum and internal quality attributes since mostly irregular correlations are found, or at least how they are exposed.

·         Conclusions appear disjointed and not logically linked to the argument throughout the text.

Author Response

Dear reviewer

Thank you for your comments. We tried to address accordingly

Why was the sensory evaluation carried out independently for the two kiwi cultivars and moreover, why were not the same time intervals chosen?

     Because they are different mainly in flesh color, also, they have different natural storage life time.

This was explained better now in material and methods with references:

The storage time considered for both cultivars was according to their usual storage capacity, up to 5months for ‘Jintao’ and 6 for ‘Hayward’ (Antunest et al., 2018).

• Regarding spectroscopic analysis, can the use of different equipment not affect the final result?

The differences were minimal and considered as reported in the reference:

Afonso, A. M.; Antunes, M. D.; Cruz, S.; Cavaco, A. M.; Guerra, R. Non-destructive follow-up of ‘Jintao’ kiwifruit ripening through VIS-NIR spectroscopy–individual vs. average calibration model’s predictions. Postharvest Biol. Technol., 2022, 188, 111895. https://doi.org/10.1016/j.postharvbio.2022.111895

• The results are on the whole poorly discussed, no distinctive feature of this work appears among the many articles available.

Discussion was improved with new recent references.

• Figures 1 and 2 are difficult to read, please give more in-depth comments.

Figures were replaced for better understanding

• It is unclear in the text the correlation between reflectance spectrum and internal quality attributes since mostly irregular correlations are found, or at least how they are exposed.

      Results are preliminar for reflectance, but even though they show to be promising for further studies as stated in the text.

• Conclusions appear disjointed and not logically linked to the argument throughout the text.

      Conclusion was improved

Round 2

Reviewer 1 Report

Comments

 In this paper, ROC analysis was used to evaluated and analyzed the sensory characteristics of the yellow-fleshed variety "Jintao" and the green-fleshed variety "Hayward" during 3-year storage period and whether typical Vis-NIR spectroscopy can be used to determine the optimal cooking period was studied.The logic of the paper is reasonable, and the research content has certain market application value. It recommends to publish after minor review in “Horticulture”. There are some improvements as follows:

1. In keywords,‘Jintao’and‘Hayward’should be replaced with kiwifruit.

2. Line 88-103, the author should add references to prove the experimental method.

3. In conclusion and discussion, the author should include photos of two kiwifruit during storage.

4. Line 156 , 169 and 190, blank lines should be deleted.

5. In table 3 ,for Hayward kiwifruit, author chose a storage period of 74, 131, 172 days in 2019, but chose a storage period of 53, 123, 152days in 2021. The author should explain whether different storage periods have an impact on sensory evaluation.

The language is fluent and only requires minor modifications

Author Response

Dear Reviewer

Thank you for your comments, we tried to answer accordingly, now with blue letter colors.

Comments

 In this paper, ROC analysis was used to evaluated and analyzed the sensory characteristics of the yellow-fleshed variety "Jintao" and the green-fleshed variety "Hayward" during 3-year storage period and whether typical Vis-NIR spectroscopy can be used to determine the optimal cooking period was studied.The logic of the paper is reasonable, and the research content has certain market application value. It recommends to publish after minor review in “Horticulture”. There are some improvements as follows:

1. In keywords,‘Jintao’and‘Hayward’should be replaced with kiwifruit.

Corrected in blue letters.

2. Line 88-103, the author should add references to prove the experimental method.

Section 2.3 was corrected and added 3 new references:

Workman Jr, J. J. A review of calibration transfer practices and instrument differences in spectroscopy. Appl. Spectrosc., 2018, 72(3), 340-365. https://doi.org/10.1177/0003702817736064

Greensill, C.V.; Walsh, K.B. Calibration transfer between miniature photodiode array-based spectrometers in the near infrared assessment of mandarin soluble solids content. J. Near Infrared Spectrosc., 2002, 10, 27–35. https://doi.org/10.1255/jnirs.318

Tian, S.; Liu, W.; Xu, H. Improving the prediction performance of soluble solids content (SSC) in kiwifruit by means of near-infrared spectroscopy using slope/bias correction and calibration updating. Food Res. Int., 2023, 170, 112988. https://doi.org/10.1016/j.foodres.2023.112988

3. In conclusion and discussion, the author should include photos of two kiwifruit during storage.

We are very sorry, but we do not have good quality photos to include. We believe that the explanations can be enough.

4. Line 156 , 169 and 190, blank lines should be deleted.

Lines were deleted.

5. In table 3 ,for Hayward kiwifruit, author chose a storage period of 74, 131, 172 days in 2019, but chose a storage period of 53, 123, 152days in 2021. The author should explain whether different storage periods have an impact on sensory evaluation.

Explanation was provided lines 215-220:

As climacteric fruit, kiwifruit ripen through storage reaching the eating-ripe stage faster or latter according to their main ripening parameters at harvest time, which are SSC and Firmness [43]. The evolution of these parameters depends, not only of the harvest period, but also of pre and postharvest storage conditions [2,7]. In our case, there were both effects which explain the differences, mainly at the end of storage.     

Reviewer 2 Report

• All the questions proposed were explained too simply and one-sided. For instance,  question 3 and 9.  The total number of samples required for the test should be explained in line 58.  The authors fail to positive response. The materials and methods section lacks relevant pictures.The authors fail to  improve the section description.

Author Response

Dear Reviewer

Thank you for your comments, we tried to answer accordingly, now with blue letter colors.

 

Comments and Suggestions for Authors

• All the questions proposed were explained too simply and one-sided. For instance,  question 3 and 9. 

 

 

• The total number of samples required for the test should be explained in line 58.  The authors fail to positive response.

This is the answer to question 3

Explained in lines 77-81:

The taste panels were done by people recruited from faculty staff and students, which were trained to be familiar with such type of panels. These are people which usually participate in the taste panels done at the faculty. Groups with 15 to 32 elements, according to their availability due to covid-19 times, did the sensory evaluations based on a 7-point hedonic scale (1 = dislike extremely, 2 = dislike, 3= slightly dislike, 4 = neither like nor dislike, 5 = slightly like, 6 = like, 7 = like very much) [28],

 

 

 

• The materials and methods section lacks relevant pictures. The authors fail to  improve the section description.

This is the answer to question 9

We are very sorry, but we do not have good quality photos to include.

We believe that with the improvements done now,  asked by reviewer 1 and 2, explanations can be enough.

Reviewer 3 Report

I am satisfied of the answers and corrections supplied by authors. The paper seems to be ready to be published.

Author Response

Dear Reviewer

Thank you for your comments.

 

 

 

Comments and Suggestions for Authors

I am satisfied of the answers and corrections supplied by authors. The paper seems to be ready to be published.

Round 3

Reviewer 2 Report

Well done.