Lactose-Free Dairy Products: Market Developments, Production, Nutrition and Health Benefits

Round  1

Reviewer 1 Report

It is a fine review on a relevant topic. It covers the aspect of market and category development in connection with processing and quality aspects of lactose reduced products in a fine way.

The molecular aspects of the quality changes could be adressed more directly, but rely on the scope of the paper.

Figure 2 could contain more processing details, also highlithting more the mentioned differences between pre- and post-hydrolyzed practises.

Line 140-143: How much increased dairy intake to obtain this?

Line 197: change chapter to section 

Author Response

The molecular aspects of the quality changes could be adressed more directly, but rely on the scope of the paper.

In paragraph 2.1 an extra sentence was included: "Consequently, the lactose content may be very low (< 0.1 g/L) but the glucose and galactose content of lactose-free milk will be ~25 g/L." 

Figure 2 could contain more processing details, also highlithting more the mentioned differences between pre- and post-hydrolyzed practises.

We have adapted Figure 2 to include more processing details

Line 140-143: How much increased dairy intake to obtain this?

Line 197: change chapter to section 

Lines 140-143 and 197 have been adapted to include the requested data

Reviewer 2 Report

1// Key words are not appropripate. Lactase and beta-galactosidase are same. Duplication are not required. Kindly, put attention on all key words. 

2// 2.4 subheading is not required. Some parts can be included in previos section 2.2 or 2.3. I feel that content of 2.2 and 2.3 are similar. So, it is better to merge 2.2 and 2.3.

3// Some information from 2.4, can be transfered to subheading 3.

4// In section 4.2 and 4.3, if authors describe all the processes with schematic flow diagram, it will be worthy.

5// Authors need to include conclusion and future scope in the manuscript.

Author Response

1// Key words are not appropripate. Lactase and beta-galactosidase are same. Duplication are not required. Kindly, put attention on all key words. 

Key words have been adapted

2// 2.4 subheading is not required. Some parts can be included in previos section 2.2 or 2.3. I feel that content of 2.2 and 2.3 are similar. So, it is better to merge 2.2 and 2.3.

3// Some information from 2.4, can be transfered to subheading 3.

Paragraph 2.3 and 2.4 have been merged in paragraph 4.2

4// In section 4.2 and 4.3, if authors describe all the processes with schematic flow diagram, it will be worthy.

The flow diagram of Figure 2 has been adapted. Also we included a new figure 3 of a flow scheme of some of the different processes described in sections 3.2 and 3.3 (new numbering).

5// Authors need to include conclusion and future scope in the manuscript.

The last paragraph has been set apart and re-written to make the conclusions and future prospects more clear

Reviewer 3 Report

See attached Edited MS for detailed comments.

Some of the key comments are pasted below but not all.

Consider a re-structure of the paper based on the title option you choose from the advice below.

 Line 2 Title:     Consider changing title to "Lactose-free dairy products: Market development, production, nutrition and health benefits/impact". I authors want to keep structure; then I suggest "Lactose-free dairy products: Nutrition and health benefits, marketing and product development".

Lines 34-37:   This sentence is too long. it is better as 2 shorter sentences.

Line 44: What about whey protein isolate (WPI) which contains 80-90% protein but low amount of lactose?

Line 44:  Brackets within brackets. change to different forms of bracket. example change to " [WPC]"

Line 92:  This section needs to add information about the controversy of the role of lactose in enhancing calcium and divalent mineral bioavailability. Consequently, most lactose free products are fortified with 20% + higher calcium.

Line 194:

·        This section could benefit by including the Kosher and possibly Halal status of these enzymes.

·        Doesn't some yogurt products which are not necessarily lactose-free become tolerable to lactose intolerant population because the strains of the bacteria or culture produces lactase enzymes in the product and in the gut which help digest the lactose?

Line 197:  "Section" not chapter. it is awkward.

Line 206:  Many countries have different variations in the definition of lactose-free. There is no consensus on what is defined as Lactose-free, Low lactose or reduced lactose.

Lines 220-223:  Repeated use of "However". Consider rewriting.

Line 327:  A possible 3rd factor ignored here is that the fermented yogurt includes or enhances the population of bacteria/culture which produces lactase enzyme that helps to digest lactose in the gut.

 Line 423: WPI needs to be defined at 1st use. I think it is "whey protein isolate"

Lines 433-441:  I assume that this section is the "Conclusions" or "Summary". Then define it as the subtitle here.

 References: List all authors

Comments for author File: Comments.pdf

Author Response

All recommendations have been implemented. Title and structure of the review has been changed. Here some remarks on individual points. When not discussed here, the points of the reviewer have been taken over.

Line 44: What about whey protein isolate (WPI) which contains 80-90% protein but low amount of lactose?

Line 423: WPI needs to be defined at 1st use. I think it is "whey protein isolate"

WPI has been added and now defined in section 1 (line 44)

Line 92:  This section needs to add information about the controversy of the role of lactose in enhancing calcium and divalent mineral bioavailability. Consequently, most lactose free products are fortified with 20% + higher calcium.

Extra explanation has been added on the role of lactose in calcium bioavailability, including a new reference (now line 404-409). LF dairy products are not regularly extra fortified with calcium - this is specific for non-dairy products.

Line 194:

·        This section could benefit by including the Kosher and possibly Halal status of these enzymes.

Remark added on Kosher and Halal status of lactase enzymes (line 107-108)

·        Doesn't some yogurt products which are not necessarily lactose-free become tolerable to lactose intolerant population because the strains of the bacteria or culture produces lactase enzymes in the product and in the gut which help digest the lactose?

Line 327:  A possible 3rd factor ignored here is that the fermented yogurt includes or enhances the population of bacteria/culture which produces lactase enzyme that helps to digest lactose in the gut.

This is discussed in section 3.2, first bullet point (line 234-240). Special reference has been made to the role of the bacterial lactase enzyme, to clarify the reviewers point. Since this is now explained in the first bullet point, no 3rd factor needs to be postulated.

Lines 433-441:  I assume that this section is the "Conclusions" or "Summary". Then define it as the subtitle here.

As suggested, this section has been set apart and has been adapted (lines 462-473)

Round  2

Reviewer 2 Report

Authors include all information, suggested by me. I suggest it for acceptance.

Reviewer 3 Report

The quality of the paper has been improved by the revision. Thanks to the authors.