Polyphenols vs. Caffeine in Coffee from Franchise Coffee Shops: Which Serving of Coffee Provides the Optimal Amount of This Compounds to the Body
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
The authors of this manuscript, try to conduct an analysis to show which serving of coffee provide the optimal amounts of polyphenols and caffeine.
The ms is well described in most of the sections, but there are some details that the authors should be consider to increase the quality of this paper. Some of them are:
In page 1, line 33, the authors says that coffee is a food that support overall health. The definition of a food is: any nutritious susbstance that the people or animals eat or drink in order to maintain life and growth. In this sense the authors should to think if the term is correct.
In section of materials and methods the authors describe the aproach to analyse caffeine and polyphenols. In the case of caffeine, in page 3, lines 132-144 it is described some details related to the caffeine content determination and mention an in-house test procedure, but there are some details that the authours should give in detail, because it is not clear. For example the use of Carrez I and Carrez II, what is the meaning of using these chemicals?
Author Response
Reply to Reviewer no. 1
Thank you very much for the review and for your positive recommendation. Please find the detailed responses below and the corresponding revisions/corrections highlighted in track changes in the re-submitted files.
Comment 1:
„In page 1, line 33, the authors says that coffee is a food that support overall health. The definition of a food is: any nutritious susbstance that the people or animals eat or drink in order to maintain life and growth. In this sense the authors should to think if the term is correct”.
Authors’ response: Thank you for your interesting comment. In explanation, we would like to quote the definition of food from the regulation (EC) No 178/2002 of the European Parliament and of the Council of 28 January 2002 laying down the general principles and requirements of food law. Pursuant to art. 2 of this regulation ‘food’ (or ‘foodstuff’) means any substance or product, whether processed, partially processed or unprocessed, intended to be, or reasonably expected to be ingested by humans. ‘Food’ includes drink, chewing gum and any substance, including water, intentionally incorporated into the food during its manufacture, preparation or treatment. ‘Food’ shall not include:
- feed
- live animals unless they are prepared for placing on the market for human consumption;
- plants prior to harvesting;
- medicinal products within the meaning of Council Directives 65/65/EEC and 92/73/EEC;
- cosmetics within the meaning of Council Directive 76/768/EEC
- tobacco and tobacco products within the meaning of Council Directive 89/622/EEC
- narcotic or psychotropic substances within the meaning of the United Nations Single Convention on Narcotic Drugs, 1961, and the United Nations Convention on Psychotropic Substances, 1971;
- residues and contaminants;
- medical devices within the meaning of Regulation (EU) 2017/745 of the European Parliament and of the Council
Therefore, in the light of this provision, the classification of coffee as a food does not raise any doubts in our opinion, but of course, in the past it was believed that coffee did not contain nutrients and, for example, in Poland in the 1980s, coffee was classified only as a stimulant in food law. Now it is known that coffee contains niacin, magnesium, fiber and other ingredients. We hope our explanations are satisfactory for you.
Comment 2:
„In section of materials and methods the authors describe the aproach to analyse caffeine and polyphenols. In the case of caffeine, in page 3, lines 132-144 it is described some details related to the caffeine content determination and mention an in-house test procedure, but there are some details that the authours should give in detail, because it is not clear. For example the use of Carrez I and Carrez II, what is the meaning of using these chemicals?”
Authors’ response: Thank you for your comment. Authors want to reply for this question. In determining caffeine content, it's crucial to remove high-molecular compounds like proteins or polysugars from the sample. These substances can interfere with chromatographic analysis, potentially impacting the accuracy of caffeine determination in coffee infusions. To address this issue, we employed Carrez I and Carrez II solutions to clarify the coffee brew during sample preparation for chromatographic analysis.
In manuscript the sentence: “For purification, we added 1 mL each of Carrez I (15 g of potassium hexacyanoferrate (II) dissolved in 100 mL of distilled water) and Carrez II (30 g of zinc sulphate dissolved in 100 mL of distilled water) to the sample” was changed on: “To effectively remove high-molecular compounds, we added 1 ml each of Carrez I and […]”.
Reviewer 2 Report
Comments and Suggestions for Authors
This manuscript describes the contents of polyphenols and caffeine and their ratio in coffee products purchased from franchise coffee shops in Poland. Changes should be made before further processing.
1. The assessment of most favourable ratio of caffeine to total polyphenols a cup of coffee should not be based on only one indicator (total polyphenols/caffeine), because individual compounds of polyphenols show quite different physiologically beneficial functions. As shown in Table 2, the total content of polyphenols in Espresso was more than double that in Americano. However, the detected individuals of polyphenols were not significantly different between them, suggesting that the great differences will be in the unknown polyphenol individuals.
2. Typos should be carefully corrected, such as (232.9 ±63.9 mg/100 mL and 198.6 ±68.3 mg/100 mL respectively in Line 22.
3. About the descriptions “the safe intake of this alkaloid for adults is up to 400 mg per day, and up to 200 mg for pregnant women.” (In Line 40), reference should be cited.
Author Response
Reply to Reviewer no. 2
Thank you very much for the review and for your comments. Please find the detailed responses below and the corresponding revisions/corrections highlighted in track changes in the re-submitted files.
Comment 1:
“The assessment of most favourable ratio of caffeine to total polyphenols a cup of coffee should not be based on only one indicator (total polyphenols/caffeine), because individual compounds of polyphenols show quite different physiologically beneficial functions. As shown in Table 2, the total content of polyphenols in Espresso was more than double that in Americano. However, the detected individuals of polyphenols were not significantly different between them, suggesting that the great differences will be in the unknown polyphenol individuals”.
Authors’ response: Thank you for your comment. Authors want to reply for this suggestion. Of course, that all individual phenolic compounds have different physiologically effect and beneficial function. In presented manuscript not everything phenolics ware possible for identification and quantification. Our team can identified only those, which standards we had. In time of coffee beverage consumption our body use all phenolics not only one or two. So, in authors opinion, showing caffeine/polyphenols ratio was one of the best idea for results presentation. It is well known that in coffee beverages are much more (not known) polyphenols compounds. Form the consumer point of view when a lot of ratio index would be in tables, it could be more confused which coffee beverages is the best for them. We hope our explanations are satisfactory for you.
Comment 2:
“Typos should be carefully corrected, such as (232.9 ±63.9 mg/100 mL and 198.6 ±68.3 mg/100 mL respectively in Line 22.”
Authors’ response: Thank you for pointing this out. Typos have been corrected.
Comment 3:
“About the descriptions “the safe intake of this alkaloid for adults is up to 400 mg per day, and up to 200 mg for pregnant women.” (In Line 40), reference should be cited.”
Authors’ response: There was the same references for both sentences “…in light of current knowledge, the safe intake of this alkaloid for adults is up to 400 mg per day, and up to 200 mg for pregnant women. Single doses of caffeine up to 200 mg (about 3 mg/kg bw for a 70-kg adult) do not give rise to safety concerns [7,8].” but as you suggested, we split it into two parts:
“in light of current knowledge, the safe intake of this alkaloid for adults is up to 400 mg per day, and up to 200 mg for pregnant women [7,8]. Single doses of caffeine up to 200 mg (about 3 mg/kg bw for a 70-kg adult) do not give rise to safety concerns [7].”
Round 2
Reviewer 2 Report
Comments and Suggestions for Authors
The authors responded to the comments and it can be accepted.
