Round 1

Reviewer 1 Report

This is an interesting attempt to review methods for preserving and applying probiotic microorganisms. It is well structured with appropriate number of recent literature. However since the authors would like to focus on probiotic formulations the part for encapsulation and immobilisation and the new trends could be more expanded. The initial part on the old drying methods that appy to all microorganisms could be shortened and the relevant schemes to be removed.

The information in the tables could be summarised eg. in table 1 all cases of the same drying method with <1 log reduction could be grouped.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

General comments:

The manuscript consists of a review of the current trends in the production of probiotic formulations to be consumed by animals and humans. This review includes a discussion of different drying methods and their improvements with special interest in the process conditions, microorganisms, and protective substances. Moreover, a discussion on the factors (thermal, osmotic, oxidative and acidic stress, dehydration and shear forces) affecting the quality and stability of the final probiotic preparations is provided jointly with some alternatives to alleviate the effects of these factors.

The English language is correct, the scientific merit of the paper is appropriate and the discussion provided on the different issues is clearly presented and supported.

However, in some issues of the manuscripts, minor changes and an additional explanation are needed.

Other considerations are as follows:

2.1.3. Vacuum drying (Page 5, line 177): Replace hours with h.

2.2. Novel immobilization methods (Page 7, lines 231 and 234): Replace minutes or minute with min.

Page 8, line 249: Provided the year for Yoha et al.

Page 8, line 253: Replace probioitcs with probiotics.

2.4. Factors affecting the viability of probiotics during drying (Page 9, lines 302-303): Provided references to support this affirmation.

Page 10, line 334: Replace Lactobacillus plantarum with L. plantarum.

Page 11, line 400: Replace Lactobacillus reuteri with L. reuteri.

Page 17, line 536: Replace Lactobacillus casei with L. casei.

Page 18, lines 573-578: Explain why the cell-free culture supernatants from cultures of probiotics (Lopes et al. [53]), showed antimicrobial activity towards Escherichia coli, Cutibacterium acnes and Pseudomonas aeruginosa.

Page 18, lines 578-579: Provide more evidence for this affirmation “Most of the used strains also displayed the ability to prevent biofilm formation”.

Figures 1 (page 3), 2 (page 4), 3 (page 5), 4 (page 6), and 5 (page 7) should be improved.