Ultrasonication Effects on Quality of Tea-Based Beverages
Round 1
Reviewer 1 Report
This paper is interesting because its subject is of great interest at the moment and is related to the use of green technologies for preservation in food industry. However, there are some aspects that must be improved by the author, that are further presented.
English language must be improved
The title of the article should reflect its content and should be reconsidered.
Abstract must be improved, the objective of the study must be stated clearly and the main findings should be presented.
Within Introduction section the author should present the conventional methods used for tea based beverages obtaining – their advantages and disadvantages.
The mechanism of action of ultrasonication must be presented, and also the advantages and disadvantages for its use.
There are some information presented regarding the bio-active compounds and also microbial aspects regarding tea ultrasonication, but not enough. The author should extend their research in this 2 areas for a better understanding of using ultrasound as a method of preservation in food industry and beverage industry.
Author Response
Manuscript has been revised as reviewers’s suggestion as follows. Also, section for Ready-to-drink beverages, future perspectives and conclusion has been revised in manuscript with yellow colored.
Reviewer’s comments:
Reviewer#1:
This paper is interesting because its subject is of great interest at the moment and is related to the use of green technologies for preservation in food industry. However, there are some aspects that must be improved by the author, that are further presented.
Comment 1: English language must be improved.
Response to comment 1: I appreciated the reviewer’s comments. I had a native speaker proof-check the manuscript. The suggestions were incorporated into the revised manuscript.
Comment 2: The title of the article should reflect its content and should be reconsidered.
Response to comment 2: The title of article has been revised. The new title is ‘Ultrasonication effects on quality of tea based beverages’.
Comment 3: Abstract must be improved, the objective of the study must be stated clearly and the main findings should be presented.
Response to comment 3: Abstract has been revised as reviewer’s suggestions. Aim of this review has been stated in manuscript.
Comment 4: Within Introduction section the author should present the conventional methods used for tea based beverages obtaining – their advantages and disadvantages.
Response to comment 4: The following sentences were added to introduction section:…… However, nutritional properties, such as vitamins, antioxidants, and polyphenols, as well as sensorial properties are affected during the thermal treatments [7]. The high energy and time consumption and low extraction yield are caused by conventional thermal treatments [8]…..
Comment 5: The mechanism of action of ultrasonication must be presented, and also the advantages and disadvantages for its use.
Response to comment 5: The following sentences were added to 4.1. Emerging technique- Ultrasound Section.
…. Ultrasonication systems can be performed by sound waves with frequency at 20 kHz using water baths, probes, sonoreactors, and microplate horns [63]. The distruption of the cell walls by ultrasonication penetrates the solvent into the sample to release the target compounds. The mass transfer through the cell membrane is improved to increase the extraction yield with reduction of time and solvent consumption and energy saving [64]. In addition, ultrasonication which carried out at low temperature minimizes the thermal damage of extracts and loss of volatile components [65]. However, ultrasonication system has disadvantages such as being expensive, occurring undesirable changes in molecules and requiring optimization [66]……
….The mechanism of ultrasonication based on cavitation phenomena which formed of micro channels in the samples to penetrate the solvent [71]. Ultrasonic waves cause cavitation bubbles to form through a series of compression and rarefaction cycles. These bubbles can enlarge in size due to coalescence and collapse during compression phase creating hot spot and accelerating biochemical reactions [72]. Pore formation due to sonoporation contributes to release of bioactive compounds from cellular matrices [73]. ….
Comment 6: There are some information presented regarding the bio-active compounds and also microbial aspects regarding tea ultrasonication, but not enough. The author should extend their research in this 2 areas for a better understanding of using ultrasound as a method of preservation in food industry and beverage industry.
Response to comment 6: The following sentences were added to 4.1.1. Bioactive components aspects
The ultrasonic probe (26 kHz) and ultrasonic bath (40 kHz) were performed in terms of extraction yield and total phenolic content (TPC) for different brands of tea. Among different brands of tea, the maximum TPC in Haritham brand of tea was found 71.13 and 48.88 mg equivalent to gallic /g DW at 40 oC and 40% power respectively for 26 and 40 kHz. Ultrasonic probe of frequency at 26 kHz showed better results than ultrasonic bath of frequency at 40 kHz [74] (Table 2). It might be cavitation growth and collapse were better in lower frequency due to fast mass transfer [75]…..
….. TPC was found to be 78.97±1.85 mg GAE/g for 30 min in ultrasonication brewing system, whereas 19.51±0.76 mg GAE/g for 360 min in conventional brewing system. The extraction of phenolics was increased with 4 times in comparison to conventional cold brewing. However, brewing time reduced from 6 h to 30 min by ultrasonication brewing [77]……
……Horzic et al. [11] investigated that effect of ultrasound and conventional hot water extraction on bioactive compounds of yellow tea. The maximum TPC extraction yield was performed at 67 oC and 30 min with 75% aqueous ethanol by ultrasound probe……
…….Some herbs, which are non-Camellia tea varieties, have been used to form of tea based beverages in China [81]. The vine tea which is known as Ampelopsis grossedentata is used in health supplements and medicine in China due to rich polyphenols [78]. Vine tea is consumed by soaking in boiling water. A traditional beverage in China, vine tea, treated with ultrasonication to extract polyphenols. The maximum polyphenols were extracted from vine tea by 70% ethanol at 70 oC for 40 min with ultrasonication [78] (Table 2)…
There are few studies investigated that effect of ultrasonication system based on microbial inactivation of tea based beverages production. In recent years, microbial inactivation of tea-based beverages has been developing.
Reviewer 2 Report
Adding explanation on vine tea will be better.
Author Response
Reviewer#2:
Comment 1: Adding explanation on vine tea will be better.
Response to comment 1: The following sentences were added to 4.1.1 Bioactive components aspects Section.
……Some herbs, which are non-Camellia tea varieties, have been used to form of tea based beverages in China [81]. The vine tea which is known as Ampelopsis grossedentata is used in health supplements and medicine in China due to rich polyphenols [78]. Vine tea is consumed by soaking in boiling water. A traditional beverage in China, vine tea, treated with ultrasonication to extract polyphenols. The maximum polyphenols were extracted from vine tea by 70% ethanol at 70 oC for 40 min with ultrasonication [78]…….
Reviewer 3 Report
The manuscript is supposed to review ultrasound techniques in preserving tea-beverages, however, not many papers about the technique is reviewed. The manuscript has issue in structure, which must be re-organized to publish as a valuable reference.
1. The entire manuscript doesn’t include any figure, which is rare for a review paper.
2. Section 2 ,3 and 6 are irrelevant to the topic that preserving of tea-beverages or ultrasound.
3. Section 5 should be the critical part of the entire review, however, not much work are reviewed in this section.
4. 5.1.3 is too thin. As mentioned in introduction section, “Challenges at industrial setup of ultrasound system for tea-based beverages are discussed at the end of this review”, however, 5.1.3 didn’t talk about this interesting topic sufficiently.
Author Response
Reviewer#3:
The manuscript is supposed to review ultrasound techniques in preserving tea-beverages, however, not many papers about the technique is reviewed. The manuscript has issue in structure, which must be re-organized to publish as a valuable reference.
Comment 1: The entire manuscript doesn’t include any figure, which is rare for a review paper.
Response to comment 1: Figure 1 (The manufacturing process steps of tea production) and Figure 2 (Processing of tea beverages) have been added in Manuscript with yellow colored.
Comment 2: Section 2, 3 and 6 are irrelevant to the topic that preserving of tea-beverages or ultrasound.
Response to comment 2: Section 2, 3 and 6 have been combined and rearranged under the new section 2 which is title of Tea.
Comment 3: Section 5 should be the critical part of the entire review, however, not much work are reviewed in this section.
Response to comment 3: The following sentences were added to Section 5 which is new section 4.
…… Among the manufacturing steps, extraction is the crucial step for tea beverage production. To converting raw tea leaves into a beverage, the conventional extraction techniques such as heating, boiling or refluxing were carried out [6]…….
…… Ultrasonication systems can be performed by sound waves with frequency at 20 kHz using water baths, probes, sonoreactors, and microplate horns [63]. The distruption of the cell walls by ultrasonication penetrates the solvent into the sample to release the target compounds. The mass transfer through the cell membrane is improved to increase the extraction yield with reduction of time and solvent consumption and energy saving [64]. In addition, ultrasonication which carried out at low temperature minimizes the thermal damage of extracts and loss of volatile components [65]. However, ultrasonication system has disadvantages such as being expensive, occurring undesirable changes in molecules and requiring optimization [66]…….
…….The mechanism of ultrasonication based on cavitation phenomena which formed of micro channels in the samples to penetrate the solvent [71]. Ultrasonic waves cause cavitation bubbles to form through a series of compression and rarefaction cycles. These bubbles can enlarge in size due to coalescence and collapse during compression phase creating hot spot and accelerating biochemical reactions [72]. Pore formation due to sonoporation contributes to release of bioactive compounds from cellular matrices [73].……
…. ..The ultrasonic probe (26 kHz) and ultrasonic bath (40 kHz) were performed in terms of extraction yield and total phenolic content (TPC) for different brands of tea. Among different brands of tea, the maximum TPC in Haritham brand of tea was found 71.13 and 48.88 mg equivalent to gallic /g DW at 40 oC and 40% power respectively for 26 and 40 kHz. Ultrasonic probe of frequency at 26 kHz showed better results than ultrasonic bath of frequency at 40 kHz [74] (Table 2). It might be cavitation growth and collapse were better in lower frequency due to fast mass transfer [75]…..
….. TPC was found to be 78.97±1.85 mg GAE/g for 30 min in ultrasonication brewing system, whereas 19.51±0.76 mg GAE/g for 360 min in conventional brewing system. The extraction of phenolics was increased with 4 times in comparison to conventional cold brewing. However, brewing time reduced from 6 h to 30 min by ultrasonication brewing [77]……
……Horzic et al. [11] investigated that effect of ultrasound and conventional hot water extraction on bioactive compounds of yellow tea. The maximum TPC extraction yield was performed at 67 oC and 30 min with 75% aqueous ethanol by ultrasound probe……
…….Some herbs, which are non-Camellia tea varieties, have been used to form of tea based beverages in China [81]. The vine tea which is known as Ampelopsis grossedentata is used in health supplements and medicine in China due to rich polyphenols [78]. Vine tea is consumed by soaking in boiling water. A traditional beverage in China, vine tea, treated with ultrasonication to extract polyphenols. The maximum polyphenols were extracted from vine tea by 70% ethanol at 70 oC for 40 min with ultrasonication [78] (Table 2)…
Comment 4: 5.1.3 is too thin. As mentioned in introduction section, “Challenges at industrial setup of ultrasound system for tea-based beverages are discussed at the end of this review”, however, 5.1.3 didn’t talk about this interesting topic sufficiently.
Response to comment 4: The following sentences were added to Section 5.1.3 which is new section 4.1.3.
……The design of equipment and usage of novel technologies are vital for industrial applications. The ultrasonication system for tea based beverages will provide reduced energy consumption and increased extraction yield of bioactive tea compounds to integrate the industry. Ultrasonic bath and probe are widely used industrially. The several factors such as instrumentation, batch/flow process, kinetics, economics, and energy consumption have been affected on the industrial scale of extraction techniques [83]. Hielscher (Germany) and REUS (France) develop the scale-up ultrasound extraction systems [72]…..
…… To solve this problem, the continuous system will use for ultrasonication system on industrial scale or ultrasound probes will use on each side of the extractor tank with an agitation system [83]. For this purpose, Hielscher Company has produced a devices of range power from 50 to 400 W for lab-scale and from 500 to 16,000 W for industrial scale. REUS Company has also developed a range of reactors from pilot (30 to 50 L) and industrial scale (500 to 1000L). Morover, Giotti (Italy) is designed by four continuous batch systems with ultrasound on each side of the tank and agitation system [72]. There are few studies investigated that effect of ultraonication system based on industrial scale on tea based beverages production…….
Round 2
Reviewer 1 Report
The authors improved the manuscript and is ready for publication.
Reviewer 3 Report
Authors have addressed all issues well. I recommend a publication of the work.
