Valorization of Carob Fruit Residues for the Preparation of Novel Bi-Functional Polyphenolic Coating for Food Packaging Applications

Round 1

Reviewer 1 Report

The manuscript deals with the valorization of carob fruit residues for the preparation of novel bi-functional polyphenolic coating and their potential applications in food packaging (coating). Paper is well written and in scope of the journal. Standard methodologies were used in the paper and interesting results are presented.

My major critics is related to Materials and methods and some Result (discussion), it is not well written, and discussion should be improved in some parts.

Line 64-240: Did you prepare only one extract of carob fruits and how many replicated did you do in all assays (phenols, antimicrobial tests TBARS . . .)

Line 2013-2014: How did you decided the antimicrobial activity of coated surfaces was slight (+), moderate (++) or high antimicrobial activity (+ + +)? Did you measure diameter around coated slides where was no growth of bacteria or . . . ? Please add some sentence about these.

Line 237: I suppose that was 95 °C not 950 °C

For determination of anti-Listeria activity of coatings incubation was for 5 days and for measurement the inhibition of listeria growth was 3 days- is there special reason for

Figure 4. You did not mention in the discussion the reason for the lower bacterial growth after 5 days of storage compared to the first day, even in the control sample. Is there any explanation for this?

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript deals with the valorization of carob fruits residues for the preparation of novel bi-functional polyphenolic coating for food packaging applications.

Please separate values from units, e.g. “37 °C” not “37°C”.

Abstract

Line 14- “The  food  industry  has  turn  the  interest  on  the  development  of  biomaterials  due  the  increasing awareness of environmental protection associated to plastic wastes. Although, several biopolymers have been evaluated for the food packaging, the use of polyphenolic coatings has been unexplored. The purpose of this work was to develop an antioxidant and antimicrobial coating  for  food  packaging  through  the polymerization  of  carob  phenolics.”???but plastic was used in this study. No alternative to plastic materials was presented. The abstract must be revised.

Introduction

Line 41- “Taking  into  consideration  the  above,  researchers  and  food  industries  pay  attention  to  develop alternative food packaging in order to minimize the environment impact.”?? This section must be revised. The authors must discuss better the reduction of food wastes (carob residues and others) rather than the reduction of plastics, since in the present study, plastic packaging was used in all tested salmon samples.

Results

Line 95- “9.3 nmol Trolox cm -2  and 30.6 nmol Trolox cm -2”?? equivalents of Trolox?

Line 154- “Our  results  highlighted  the  potency  of  polyphenolic  coating  to  act  as  anti-Listeria  agent  for salmon packaging (Figure 4).”??Please add average and standard deviation. Moreover, please add different superscript letters for significant differences.

Materials and methods

Pictures of each fish sample?fish colour?fish pH??wettablility??colour of coating solution??

Line 169- “1 Kg”??Please replace by “1 kg”.

Line 173- “KHz”??Please replace by “kHz”.

Line 217- “The fresh salmon  was parcelled out in slices of 25 g.”?? enough for all analyses??5 g for TBARS, 5 g for peroxide value and 25g for Listeria growth??

Line 219- “10 μL L. monocytogenes 10 6  cfu mL -1”???Please present the correct value used.

Line 222- “vacuum-packaged”?? packaging material??

Line 223- “coating was applied on the interior of plastic bag”??different packaging material from control??

Conclusion

Line 260- “In  conclusion,  the  development  of  “green”  polyphenolic coatings for food packaging is a promising research area as these coatings have been  used successfully for the production materials of medical and mechanical interest.”?? Please rephrase.

References

Please format the title of each article according to the guide for authors.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Conclusion

Line 292- “The  optimization  of  preparation  and  application  of  coatings may will further improve its performance.”???Please rephrase.

Lone 293- “In conclusion, the present study opens neew horizons for the uses of “green” polyphenolic coatings in the food packaging as these coatings have been only utilized for the production materials of medical and mechanical interest.”???There are several studies in the literature reporting the use of coatings from food wastes. Please rephrase. Also correct typos.

Author Response

     see attachment

Author Response File: Author Response.pdf