# Effect of Ultrasound on Henna Leaves Drying and Extraction of Lawsone: Experimental and Modeling Study

^{1}

^{2}

^{3}

^{4}

^{5}

^{6}

^{*}

## Abstract

**:**

^{3}) at 40, 50 and 60 °C with a constant air velocity (1 m/s). As expected, both the increase of temperature and the application of ultrasound decreased the drying time and increased the rate of extraction of the lawsone. The values of the effective diffusion coefficients obtained were used to quantify this influence showing the value increases with higher drying temperature and the application of ultrasound. Moreover, the influence of temperature was quantified by the estimation of the activation energy from an Arrhenius-type equation (46.25 kJ/mol in the case of drying without ultrasound application and 44.06 kJ/mol in the case of ultrasonically-assisted drying). Regarding the influence of studied variables on lawsone extraction yield, the higher is the temperature, the lower is the yield, probably linked with lawsone degradation reaction due to thermal treatment. On the contrary, the application of ultrasound improved the extraction yield mainly at the lower drying temperature tested of 40 °C.

## 1. Introduction

## 2. Materials and Methods

#### 2.1. Drying Experiment

^{3}). In every run, a constant air velocity of 1 m/s was applied, and the process was stopped when the samples lost 75% of their initial weight. Each drying condition was tested at least in triplicate.

#### 2.2. Drying Kinetics

**Dr**) of henna leaves was calculated using the following equation [21]:

**MR**is the dimensionless moisture content,

**X**(

**t**) is the moisture content after a drying time (

**t**) (kg water/kg dry matter, d.m.),

**X**is the initial moisture content of samples (kg water/kg d.m.) and

_{0}**X**(kg water/kg d.m.) is the equilibrium moisture content.

_{eq}#### 2.3. Lawsone Extraction and Separation

**R**) was calculated according to Equation (3):

_{e}**R**is the extraction yield and

_{e}**M**is the weight

_{L}## 3. Mathematical modeling

#### 3.1. Determination of Effective Moisture Diffusivity

**D**is the effective diffusion coefficient (m

_{eff}^{2}/s), t is the drying time (s) and

**x**is the moisture transport direction. To integrate this equation, the following boundary and initial conditions were assumed:

- -
- Uniform initial moisture content: $X\left(x,0\right)={X}_{0}$
- -
- Symmetry of moisture transport: $\frac{\partial X}{\partial x}{/}_{x=0}=0$
- -
- External resistance to mass transport negligible, which means that the equilibrium moisture content at the surface is only achieved at the beginning of the drying process: $\mathrm{X}\left(\mathrm{L},\mathrm{t}\right)={\mathrm{X}}_{\mathrm{eq}}$

**D**can be easily calculated from the slope of the relationship between MR and drying time (Equation (8)):

_{eff}#### 3.2. Activation Energy

**D**can be quantified by the activation energy (

_{eff}**E**) which can be calculated by using an Arrhenius-type equation [25] as follows:

_{a}**D**is a pre-exponential factor of the Arrhenius equation (m

_{0}^{2}/s),

**E**is the activation energy (kJ/mol),

_{a}**T**is the drying temperature (K) and

**R**is the constant of ideal gases (kJ/molK).

## 4. Results and Discussion

#### 4.1. Experimental Drying Kinetics

#### 4.2. Effective Diffusivity and Activation Energy

**D**) and the correlation coefficient at different temperatures (40, 50 and 60 °C), with and without the application of ultrasound, are shown in Table 2. The correlation coefficient was above 0.98 in every experiment, which indicates that the model adequately fit the experimental data. The

_{eff}**D**values obtained ranged between 0.7094 × 10

_{eff}^{−9}and 2.5547 × 10

^{−9}m

^{2}/s in the case of conventional drying experiments and 1.0234 × 10

^{−9}and 2.8164 × 10

^{−9}m

^{2}/s in the case of ultrasonically-assisted ones. These values are in the same range as others given in the literature [26,27].

**D**identified at the temperature tested. The ultrasound effects could contribute to accelerate the water movement and removal from the henna leaves. Regarding the temperature, it was observed than the the

_{eff}**D**increased with the drying temperature. To evaluate the influence of drying temperature in drying kinetics, an Arrhenius-type equation was used to calculate the activation energy. Thus, the natural logarithm of the identified values of

_{eff}**D**was represented as a function of the temperature inverse, and, from the slope of this relation, the activation energy was calculated.

_{eff}#### 4.3. Influence of Drying in Lawsone Content

## 5. Conclusions

## Author Contributions

## Funding

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## Nomenclature

D_{0} | Pre-exponential factor of the Arrhenius equation [m^{2}/ s] |

D_{eff} | Effective diffusivity [m^{2}/s] |

E_{a} | Activation energy [kJ/mol] |

L | Half-thickness of el Henna’s leaves [m] |

M | Mass of the dry sample [g] |

MR | Dimensionless moisture content [-] |

M_{L} | Lawsone mass [g] |

Re | Yields of lawsone [-] |

r | Correlation coefficient [-] |

t | Time |

T | Temperature [°C or K] |

x | Mass transport direction [m] |

X | Moisture content |

X_{eq} | Equilibrium moisture content [kg/kg % d.b] |

## References

- Cheriti, A.; Rouissat, A.; Sekkoum, K.; Balansard, G. Plantes de la pharmacopée traditionnelle dans la région d’El-Bayadh (Algérie). Fitoter
**1995**, 66, 525–538. [Google Scholar] - Saad, A.; Touati, B.; Draoui, B.; Tabti, B.; Abdenebi, A.; Benaceur, S. Mathematical Modeling of moisture sorption isotherms and determination of isosteric heats of sorption of Ziziphus Leaves. Model. Simul. Eng.
**2014**, 16. [Google Scholar] [CrossRef][Green Version] - Fortin, D.; Lô, M.; Maynart, G.; Arseneault, C. Plantes Médicinales du Sahel; Occasional paper: Dakar, Senegal, 1990. [Google Scholar]
- Chetty, K.M. Flowerings Plants of Chitter, 1st ed.; Students Offset Printers: Andhrapradech, India, 2008; p. 132. [Google Scholar]
- Rahmouni, N.M.; Boucherit-Atmani, Z.; Benabdallah, M.; Boucherit, K.; Villemin, D.; Choukchou-Braham, N. Antimicrobial activities of the henna extract and some synthetic naphthoquinones derivatives. Am. J. Med. Biol. Res.
**2013**, 1, 16–22. [Google Scholar] [CrossRef][Green Version] - Kamal, M.; Jawaid, T. Pharmacological Activities of Lawsonia inermis Linn.: A Review. Int. J. Biomed. Res.
**2010**, 1, 37–43. [Google Scholar] [CrossRef] - Jan, H.U.; Shinwari, Z.K.; Khan, A.A. Staining effect of dye extracted from dry leaves of Lawsonia inermis L. (henna) on Angiospermic Stem Tissue. Pak. J. Bot
**2011**, 43, 383–389. [Google Scholar] - Bennaceur, S.; Draoui, B.; Bennamoun, L.; Touati, B. Experimental study and modeling of moisture sorption Isotherms of Leaves (Waronia saharae). Phys. Energ.
**2017**, 37. Available online: https://www.semanticscholar.org/paper/Experimental-study-and-modeling-of-moisture-of-(-)-Bennaceur-Draoui/d931cc1044d5662041037798df280a137480a16e (accessed on 28 February 2021). - Cárcel, J.A.; Castillo, D.; Simal, S.; Mulet, A. Influence of temperature and ultrasound on drying kinetics and antioxidant properties of red pepper. Dry. Technol.
**2019**, 37, 486–493. [Google Scholar] [CrossRef] - Di Scala, K.; Crapiste, G. Drying kinetics and quality changes during drying of red pepper. LWT-Food Sci. Technol.
**2008**, 41, 789–795. [Google Scholar] [CrossRef] - Zhou, L.; Cao, Z.; Bi, J.; Yi, J.; Chen, Q.; Wu, X.; Zhou, M. Degradation kinetics of total phenolic Compounds, capsaicinoids and antioxidant activity in red pepper during hot air and infrared drying process. Int. J. Food Sci. Technol.
**2016**, 51, 842–853. [Google Scholar] [CrossRef] - Lechtańska, J.M.; Szadzińska, J.; Kowalski, S.J. Microwave-and infrared-assisted convective drying of green pepper: Quality and energy considerations. Chem. Eng. Process. Process Intensif.
**2015**, 98, 155–164. [Google Scholar] [CrossRef] - Carcel, J.A.; Garcia-Perez, J.V.; Riera, E.; Rossello, C.; Mulet, A. Ultrasonically assisted drying. In Ultrasound in Food Processing; Villamiel, M., Garcia-Perez, J.V., Montilla, A., Carcel, J.A., Benedito, J., Eds.; John Wiley & Sons Ltd.: Hoboken, NJ, USA, 2017; pp. 371–391. [Google Scholar]
- Musielak, G.; Mierzwa, D.; Kroehnke, J. Food Drying Enhancement by Ultrasound–A Review. Trends Food Sci. Technol.
**2016**, 56, 126–141. [Google Scholar] [CrossRef] - De la Fuente-Blanco, S.; De Sarabia, E.R.-F.; Acosta-Aparicio, V.M.; Blanco-Blanco, A.; Gallego-Juárez, J.A. Food drying process by power ultrasound. Ultrasonics
**2006**, 44, e523–e527. [Google Scholar] [CrossRef] [PubMed] - Do Nascimento, E.M.G.C.; Mulet, A.; Ascheri, J.L.R.; de Carvalho, C.W.P.; Cárcel, J.A. Effects of high-intensity ultrasound on drying kinetics and antioxidant properties of passion fruit peel. J. Food Eng.
**2016**, 170, 108–118. [Google Scholar] [CrossRef] - Fan, K.; Zhang, M.; Mujumdar, A.S. Application of airborne ultrasound in the convective drying of fruits and vegetables: A Review. Ultrason. Sonochem.
**2017**, 39, 47–57. [Google Scholar] [CrossRef] - Villamiel, M.; García-Pérez, J.V.; Montilla, A.; Carcel, J.A.; Benedito, J. Ultrasound in Food Processing: Recent Advances; John Wiley & Sons: Hoboken, NJ, USA, 2017. [Google Scholar]
- Gamboa-Santos, J.; Montilla, A.; Cárcel, J.A.; Villamiel, M.; Garcia-Perez, J.V. Air-borne ultrasound application in the convective drying of strawberry. J. Food Eng.
**2014**, 128, 132–139. [Google Scholar] [CrossRef] - Lahsasni, S.; Kouhila, M.; Mahrouz, M.; Idlimam, A.; Jamali, A. Thin layer convective solar drying and mathematical modeling of prickly pear peel (Opuntia ficus indica). Energy
**2004**, 29, 211–224. [Google Scholar] [CrossRef] - Celma, A.R.; López-Rodríguez, F.; Blázquez, F.C. Experimental modelling of infrared drying of industrial grape by-products. Food Bioprod. Process.
**2009**, 87, 247–253. [Google Scholar] [CrossRef] - Ashnagar, A.; Shiri, A. isolation and characterization of 2-Hydroxy-1, 4-Naphthoquinone (Lawsone) from the powdered leaves of henna plant marketed in ahwaz city of Iran. IJ Chemtech. Res.
**2011**, 3, 1941–1944. [Google Scholar] - Srikiatden, J.; Roberts, J.S. Measuring moisture diffusivity of potato and carrot (core and cortex) during convective hot air and isothermal drying. J. Food Eng.
**2006**, 74, 143–152. [Google Scholar] [CrossRef] - Crank, J. The Mathematics of Diffusion, 2nd ed.; Oxford Science Publication: Oxford, UK, 1975; p. 32. [Google Scholar]
- Nourhène, B.; Mohammed, K.; Nabil, K. Experimental and mathematical investigations of convective solar drying of four varieties of olive Leaves. Food Bioprod. Process.
**2008**, 86, 176–184. [Google Scholar] [CrossRef] - Kane, C.S.E.; Jamali, A.; Kouhila, M.; Mimet, A.; Ahachad, M. Single-layer drying behavior of mexican tea leaves (Chenopodium ambrosioides) in a convective solar dryer and mathematical modeling. Chem. Eng. Commun.
**2008**, 195, 787–802. [Google Scholar] [CrossRef] - Lamharrar, A.; Idlimam, A.; Alouani, A.; Kouhila, M. Modelling of thin layer solar drying kinetics and effective diffusivity of Urtica doica leaves. J. Eng. Sci. Technol.
**2017**, 12, 2141–2153. [Google Scholar] - Dhiman, A.; Sharma, K.; Goyal, J.; Garg, M.; Sharma, A. Determination of lawsone content in fresh and dried leaves of Lawsonia inermis Linn. And its quantitative analysis by HPTLC. J. Pharm. Sci. Innov.
**2012**, 1, 17–20. [Google Scholar]

**Figure 3.**Experimental drying kinetics of the henna leaves determined at different temperatures (40, 50 and 60 °C): (

**a**) without ultrasound application (Air); and (

**b**) with ultrasound application (Air + us; 20.5 kW/m

^{3}; 21.7 kHz).

**Figure 4.**Drying rate curves of leaves henna vs. moisture content at different temperatures (40, 50 and 60 °C): (

**a**) without ultrasound application (Air); and (

**b**) with ultrasound application (Air + us; 20.5 kW/m

^{3}; 21.7 kHz).

**Figure 5.**HPLC analysis for: (

**a**) pure Lawsone; and (

**b**) samples of dried leaves without ultrasound (Air) at 40 °C.

**Figure 6.**The extraction yield of lawsone extracted from henna leaves at 40, 50 and 60 °C without (Air) and with (Air + us; 20.5 kW/m

^{3}; 21.7 kHz) ultrasound application.

**Table 1.**Drying of henna leaves (1 m/s) at different temperatures, without and with ultrasound (21.7 kHz, 20.5 kW/m

^{3}). Drying time needed to reach a final moisture content of 01 kg of water/kg of dry matter (mean ± SD).

Temperature (°C) | Ultrasound Application | Time (h) |
---|---|---|

40 | No | 3.47 ± 0.63 |

50 | No | 1.97 ± 0.05 |

60 | No | 1.19 ± 0.05 |

40 | Yes | 2.64 ± 0.13 |

50 | Yes | 1.64 ± 0.17 |

60 | Yes | 1.11 ± 0.19 |

**Table 2.**Effective diffusivity (

**D**) identified for the drying of henna leaves at different temperatures, without and with ultrasound (21.7 kHz, 20.5 kW/m

_{eff}^{3}) (mean ± SD).

Temp (°C) | Air | Air + us | ||
---|---|---|---|---|

D_{eff} (m^{2}/s)10 ^{−9} | r | D_{eff} (m^{2}/s)10 ^{−9} | r | |

40 | 0.7094 ± 0.2253 | 0.9835 | 1.0234 ± 0.0398 | 0.9929 |

50 | 1.5933 ± 0.1218 | 0.9920 | 2.0882 ± 0.9859 | 0.9887 |

60 | 2.5547 ± 0.4922 | 0.9930 | 2.8164 ± 0.3576 | 0.9834 |

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |

© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Bennaceur, S.; Berreghioua, A.; Bennamoun, L.; Mulet, A.; Draoui, B.; Abid, M.; Carcel, J.A. Effect of Ultrasound on Henna Leaves Drying and Extraction of Lawsone: Experimental and Modeling Study. *Energies* **2021**, *14*, 1329.
https://doi.org/10.3390/en14051329

**AMA Style**

Bennaceur S, Berreghioua A, Bennamoun L, Mulet A, Draoui B, Abid M, Carcel JA. Effect of Ultrasound on Henna Leaves Drying and Extraction of Lawsone: Experimental and Modeling Study. *Energies*. 2021; 14(5):1329.
https://doi.org/10.3390/en14051329

**Chicago/Turabian Style**

Bennaceur, Said, Abdelaziz Berreghioua, Lyes Bennamoun, Antonio Mulet, Belkacem Draoui, Mostafa Abid, and Juan A. Carcel. 2021. "Effect of Ultrasound on Henna Leaves Drying and Extraction of Lawsone: Experimental and Modeling Study" *Energies* 14, no. 5: 1329.
https://doi.org/10.3390/en14051329