Enzyme Conditioning of Chicken Collagen and Taguchi Design of Experiments Enhancing the Yield and Quality of Prepared Gelatins

Round 1

Reviewer 1 Report

Dear authors,

The received article for review is a very good and valuable research material. It contains not only an element of innovation, but also an implementation aspect with an indication of the directions for the use of chicken waste. A detailed description of the research methodology, presentation of the results in a clear and logical way, and a thorough discussion with other authors testify to the researchers' good knowledge of the subject.

I have one suggestion for this research paper.

I propose to change the order of the chapters, keeping the traditional order of scientific papers, i.e. chapter 4. Materials and Methods, see line 599 to 802, move and insert after line 151 instead of Results (line 147).

Summing up, the work was prepared correctly in terms of content. There were no errors or other inaccuracies in the description of the methodology and research results. I apply for acceptance of the work for publication.

Reviewer 2 Report

The main goal of the present manuscript is to test through Taguchi design the yield and quality of the gelatins resulted by the enzyme conditioning of the collagen resulted from mechanically deboned chicken meat (MDCM). The article is complex and well written and presents in a logical approach the main scientific points regarding how to process the MDCM by-product into gelatin by a 3-step extraction as well as the Taguchi design with two process factors (extraction temperature and extraction time) that are tested for three levels (42, 46 and 50 C; 20, 40 and 60 min) to optimize the processing of MDCM by-product into gelatins. Moreover, the gel-forming characteristics and the surface properties of the resulted gelatins were analyzed in detail. The conclusions of this study sustain that it is possible to prepare with elevated yields, high-quality gelatins with different features, from the unused residue resulted during the production of MDCM, and thus to assure zero waste processing of the MDCM by-product. I recommend this manuscript to be accepted in the present form because it deals with an interesting topic, has a coherent approach and presents scientific results of interest for both research and practice.