Application of a MOGA Algorithm and ANN in the Optimization of Apple Drying and Rehydration Processes

Round 1

Reviewer 1 Report

There should be more comparisons of the results with data from the literature.

Author Response

Thank you for Your comments.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript entitled ‘Application of Artificial Intelligence in Apple Processing’ proposed to use the Artificial Neural Network (ANN) approach to optimize the apple drying and rehydration process for the minimization of drying time, energy consumption, color change, solid loss, and maximization of mass gain and volume gain by using a Multiobjective genetic algorithm (MOGA). The optimization work was performed correctly, and the results were reasonable. However, there are still some major issues that need to be revised or improved with the manuscript, and thus it can not be considered for publication in Process in its current form.

Major issues:

1. The title seems a little too general, as the word ‘artificial intelligence’ should involve something as automation, smart control, etc., which were not seen in this manuscript. The word ‘artificial intelligence’ appeared only twice in the whole manuscript (one in the title, and the other one in one of the literature), and was not seen in the main text, therefore it seems the title is exaggerated. In addition, ‘apple processing’ is too general, since the authors only discussed the drying and rehydration processes. Therefore, it is suggested the author should just entitle the manuscript ‘application of ANN in the optimization of apple drying and rehydration process with a MOGA algorithm’, as this is the core of this study.
2. The English writing in this manuscript is poor, and there are lots of grammar issues. The reviewer would suggest the authors to have a native speaker to review and polish the language, or seek help from some professional language writing improving service.
3. The logic in the abstract is not clear. The authors should briefly introduce the background of conducting this study, and clearly introduce the process they are trying to study and optimize. At the first glance, I feel the drying and rehydration processes are independent to each other. Without a clear definition of the system and the process, the purpose of the optimization is not clear.
4. The experimental system to perform the drying and rehydration and the experimental procedures should be clearly stated instead of referring to a literature. Each research paper should stand by itself. For example, the authors took the rehydration temperature as the only parameter in the optimization process. The authors mentioned 3 h to 6 h in line 130, but when was the rehydration considered done or how was the rehydration time determined? Since one of the optimization goals was to maximize the mass and volume gain, then in an extreme case, soak the dried apple in the water for really long time should be the solution. Isn’t it?
5. For the color change, did the authors measured the color of the apple right after drying? How did the color change during the drying and storage? Since both processes could cause significant color change of the product color. Then how did color change during the rehydration? Without such information, the optimization results were not convincible enough.
6. In line 43-74, the references cited in this paragraph were not related to apple drying and are too general. The authors should add more references that are relevant to apple drying. Please summarize the current status and problems associated with the apple drying industry, and clearly state the significance of the study showed in the current manuscript. I believe there are a lot of published studies related to apple drying, as it is not something new.
7. The introduction section in this manuscript is poorly edited, the logic of the study, such as the background, problem statement, significance, and research objectives.
8. In section 2.2, 2.3, please include the detail of the experimental design and procedures.
9. Line 138, please explain where the 0.1% accuracy came from. If this was the operation error, how did the authors control it? If not, what was the relationship between this 0.1% and the 0.001 g in line 136?
10. Line 140, what was the 5% accuracy? Was it the uncertainty? Please include a detailed methodology of the uncertainty analysis and a summary table of the accuracy and uncertainty of the measuring device and the measured parameters. A thermodynamic analysis (energy analysis) without uncertainty analysis is not convincible.
11. Equation 6, I am curious how the SL was determined? Did the authors use the same sample for the measurement of dry mass before and after rehydration? The MC measuring method must be destructive, if they are from different samples, how did the authors control the variations? Seems to me the author prepared the samples with quite large variation, particularly for the apple slice (33% error). Please explain.
12. Line 195-210, please do not simply introduce the general background method, please explain why the authors choose to use GA over other methods in their study.
13. The numbers shown in line 304 and 305 were very close to each other, were the differences statistically significant? Could the authors provide statistical analysis to the results in Table 3 if they were experimentally determined?
14. The conclusion section is more a summary of the methods and results rather than a conclusion. In addition, the wordings were almost the same as the abstract, which is not encouraged. Please concisely state the key findings and significance, novelty and contributions of this study to the academia or industry.

Minor issues:

1. The authors should avoid using too many abbreviations in the abstract and conclusion.
2. In line 16, the optimized air velocity was 1.25 m/s, however, was the two decimal digits necessary? Can you really control the air velocity that accurately?
3. In line 17 and 18, the MG, SL, VG had no units. Based on the definitions in equation 5,6 and 7, should it be better to define them as Mass gain ratio, Solid loss ratio or Volume gain ratio?
4. In line 18, the unit of the EC was GJ/kg, but in line 153, EC was defined in kJ, then in line 258, EC was expressed in MJ. The authors should be consistent in the whole manuscript. In fact, I believe in line 258 the authors made a typo.
5. In line 22, apple is the horticulture product, not the apple plantations
6. Line 29-30, why must the dehydrated apple be rehydrated before consumption or further processing?
7. Line 34-35, the energy consumption and efficiency depend highly on the drying methods and the materials being dried, the statement in this sentence is not accurate.
8. Line 36, please define what is the ‘discussed dryers’
9. Line 78-80, the logic in this sentence is wrong. Not all food quality can be described by rehydration. Instead, rehydration capability is only on of the quality attributes.
10. Line 83, did the authors mean that if there is no structural or cellular damage, the product would not hydrate?
11. Line 91-92, please add reference
12. Line 91-98, this paragraph was very general, and the readability was poor. The sentence in line 94-95 seems repetitive to the sentence in 91-92.
13. Line 112, the apples were used for conducting the experiments, not examined
14. Line 113, what was the unit of the moisture content? Please use kg water/kg dry mass or kg water/kg wet mass, as percentage is a relative value.
15. Line 116-118, please add reference for these two calculations
16. Line 125-126, what did the authors mean by ‘obtained material was mixed together’? Mix the apples dried under different conditions together?
17. Line 137, please describe the methods in detail, including the temperature and time.
18. Line 142, please add the make, country, state/province and accuracy of the scanner, is it colorimeter?
19. Please add references to equation 1, 2 and 3
20. Line 185, why did the authors use correlation coefficient R? Is it robust enough for your system? Since there were 4 predictor variables, seems to me R may not be robust enough.
21. Line 240, ‘was’ not ‘is’

Please consider the suggestions and questions carefully.

Comments for author File: Comments.pdf

Author Response

Thank you for Your comments.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The revisions are satisfactory. One minor suggestion to the authors is for the correlation coefficient. Please try with adjusted R-square instead of R-square value. It should be more robust and works better for this study.

Author Response

Dear Reviewer,
Thank you for Your comments. We used Adjusted R-square. New changes in the manuscript are highlighted in yellow.

Kind regards, 
Krzysztof Górnicki

Author Response File: Author Response.docx