Effect of material treatment methods on recovery yield, quality parameters and antimicrobial activities of essential oil obtained from turmeric leaf using hydrodistillation

Effect of different pre-treatments of leaves on color characteristic of essential oils from turmeric leaves .... Effect of different pre-treatments of leaves on acidity index of essentia

MINISTRY OF EDUCATION AND TRAINING

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION

FACULTY FOR HIGH QUALITY TRAINING

HYDRODISTILLATION GRADUATION THESIS FOOD TECHNOLOGY

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION

FACULTY FOR HIGH QUALITY TRAINING

GRADUATION PROJECT

Thesis code: 2022-18116019

LE THI CAM NHUNG Student ID: 18116026

Ho Chi Minh City, August 2022

EFFECT OF MATERIAL TREATMENT METHODS ON RECOVERY YIELD, QUALITY PARAMETERS AND ANTIMICROBIAL ACTIVITIES OF ESSENTIAL OIL OBTAINED FROM TURMERIC LEAF USING

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION

FACULTY FOR HIGH QUALITY TRAINING

GRADUATION PROJECT

Thesis code: 2022-18116019

EFFECT OF MATERIAL TREATMENT METHODS ON RECOVERY YIELD, QUALITY PARAMETERS AND ANTIMICROBIAL ACTIVITIES OF ESSENTIAL OIL OBTAINED FROM TURMERIC LEAF USING

Ho Chi Minh City, August 2022

ACKNOWLEDGEMENTS

We would like to express our very great appreciation to all of the lectures at Ho Chi Minh City University of Technology and Education in general and lecturers at the Faculty of Chemical and Food Technology especially We gained valuable knowledge and skills regarding Food Technology throughout our four years at the school

This paper and the research behind it would not have been possible without the exceptional support of my supervisor, Dr Hoang Van Chuyen - lecturer at the Department of Food Technology, Faculty of Chemical and Food Technology, Ho Chi Minh University of Technology and Education From the initial concept to the final graduation thesis, he was always enthusiastic

in his support, mentoring, and imparting knowledge and experience We are truly grateful, and

we will remember everything forever

A special thanks goes out to consultants Ho Thi Thu Trang and Nguyen Thi My Le, who are

in charge of the Department of Food Technology laboratories and Chemical Laboratories respectively Their cooperation and assistance with tools, machines, and equipment was greatly appreciated during the course of our investigation Thanks to the professors in Food Technology Workshop 1, Microbiology Laboratory, Biochemistry Laboratory, and the Sensory Lab for providing a conducive environment in which to accomplish our thesis, we are also expressing sincere gratitude to them

Finally, we would like to thank our family and friends, who have supported us throughout the process of making this thesis

Since our professional knowledge and practical experience are still limited, the report inevitably has shortcomings, we look forward to receiving your comments to make this report more complete

Thank you sincerely!

DISCLAIMER

We hereby declare that all the content presented in the graduation thesis was written by us with the guidance Ph.D Hoang Van Chuyen We also hereby certify that the contents referenced

in the graduation thesis have been correctly and fully cited in accordance with regulations

Ho Chi Minh City, August 9, 2022

Authors

Nguyen Thi Quynh Huong

Le Thi Cam Nhung

TABLE OF CONTENTS

ACKNOWLEDGEMENTS iii

DISCLAIMER iv

LIST OF FIGURES ix

LIST OF TABLES x

LIST OF ACRONYMS xi

ABSTRACT xii

Chapter 1: INTRODUCTION 1

1.1 Introduction 1

1.2 Research content 1

1.3 Research aims 2

1.4 Overall experimental design of the project 2

1.5 Research hypotheses 2

Chapter 2: LITERATURE REVIEW 4

2.1 Overview of turmeric and turmeric leaves 4

2.1.1 Origin 4

2.1.2 Characteristic 4

2.1.3 Chemical composition and application 8

2.1.3.1 Chemical composition 8

2.1.3.2 Nutritional value 10

2.1.3.3 Application 10

2.2 Overview of essential oils 12

2.2.1 Definition 12

2.2.2 Origin and development of essential oils 13

2.2.3 Physical properties and chemical compositions of essential oils 13

2.2.3.1 Physical properties 14

2.2.3.2 Chemical compositions 14

2.2.4 Applications of essential oils 17

2.3 Techniques for recovering essential oils 18

2.3.1 Distillation methods 18

2.3.1.1 Hydro-distillation (HD) 18

2.3.1.2 Water-steam distillation 18

2.3.1.3 Steam distillation (SD) 19

2.3.2 Solvent extraction 19

2.3.3 Cold pressing 20

2.3.4 Soxhlet extraction 21

2.3.5 New methods in essential oil extraction 22

2.3.5.1 Microwave-Assisted Hydro-distillation (MAHD) 22

2.3.5.2 Ultrasound-Assisted extraction (UAE) 23

2.3.5.3 Supercritical Fluid Extraction (SFE) 23

2.4.2 The main influencing factors in steam distillation 25

2.4.2.1 Diffusion 25

2.4.2.2 Hydrolysis 26

2.4.2.3 Temperature 26

2.4.2.4 Advantages and disadvantages 26

2.5 Introduction to gas chromatography with mass spectrometry (GC/MS) 27

2.5.1 Gas Chromatography (GC) 27

2.5.2 Mass Spectrometry (MS) 28

2.5.3 Gas chromatography with mass spectrometry (GC–MS) 28

2.6 A brief overview of pathogenic microorganisms in the research 28

2.6.1 Staphylococcus aureus 28

2.6.2 Escherichia coli 29

2.7 Research situation of turmeric leaf essential oil 31

2.7.1 Domestic studies on turmeric leaf essential oil 31

2.7.2 Overseas studies on turmeric leaf essential oil 31

2.7.2.1 Constituents of the Leaf Oil of Curcuma longa L from Uttaranchal 31

2.7.2.2 Chemical composition and antifungal activity of oil extracted from turmeric leaves (Curcuma longa L.) 31

Chapter 3: RESEARCH MATERIALS AND METHODS 33

3.1 Plant material 33

3.2 Tools, equipment, chemical substances 33

3.2.1 Tools, equipment 33

3.2.2 Chemical substances 33

3.3 Research diagram 34

3.4 Research methods 34

3.4.1 Experimental design 34

3.4.2 Analytical methods 36

3.4.2.1 Determination of total essential oil content in the material 36

3.4.2.2 Analysis of physicochemical quality 37

3.4.2.3 Analysis of chemical composition 39

3.4.2.4 Sensory evaluation 39

3.4.2.5 Analysis of antimicrobial activity 40

3.4.3 Statistical analysis 41

Chapter 4: EXPERIMENT RESULTS/ FINDINGS AND ANALYSIS 42

4.1 Effect of time, leave sizes, pre-treatment of leaves on essential oil content during distillation 42

4.1.1 Effect of different time on essential oils content during distillation 42

4.1.3 Effect of different time of pre-treatment on essential oils content during distillation 44 4.1.3.1 Effect of different time of Steam pre-treatment on essential oils content during distillation 44

4.1.3.2 Effect of different time of Ultrasound pre-treatment on essential oils content during distillation 44

4.1.3.3 Effect of different time of Microwave pre-treatment on essential oils content during distillation 46

4.2 Total essential oils content in the material 46

4.3 Physicochemical quality 47

4.3.1 Effect of different pre-treatments of leaves on color characteristic of essential oils from turmeric leaves 47

4.3.2 Effect of different pre-treatments of leaves on density of essential oils from turmeric leaves 48

4.3.3 Effect of different pre-treatments of leaves on viscosity of essential oils from turmeric leaves 49

4.3.4 Effect of different pre-treatments of leaves on acidity index of essential oils from turmeric leaves 50

4.3.5 Effect of different pre-treatments of leaves on saponification index of essential oils from turmeric leaves 51

4.3.6 Effect of different pre-treatments of leaves on ester index of essential oils from turmeric leaves 52

4.4 Sensory evaluation results 52

4.5 Chemical compositions of turmeric leaf essential oil 53

4.6 Antimicrobial activity 54

4.6.1 Effect of turmeric leaf oil from different treatment methods at various concentrations on the microorganism diameter of Staphlococcus areus during incubation 54

4.6.2 Effect of turmeric leaf oil from different treatment methods at various concentrations on the microorganism diameter of Escherichia coli during incubation 55

4.6.3 Effect of turmeric leaves oil concentration from different material treatment methods on microorganism diameter of S aureus and E.coli after 7 days of incubation 56

4.6.4 Effect of turmeric leaves oil concentration from different material treatment methods on growth inhibition (%) of S aureus and E.coli after 7 days of incubation 57

4.6.5 Half maximal inhibitory concentration (IC50) of 4 different types of essential oil for Staphylococcus aureus and Escherichia coli 59

Chapter 5: CONCLUSION AND RECOMMENDATIONS 60

5.1 Conclusion 60

5.2 Recommendations 60REFERENCES 62APPENDIX 71

LIST OF FIGURES

Figure 1.1 The overall experimental design 2

Figure 2.1 (a) Whole plant, (b) rhizomes of C.longa 5

Figure 2.2 Curcuma alismatifolia 6

Figure 2.3 Curcuma kwangsiensis 6

Figure 2.4 Curcuma cochinchinensis 7

Figure 2.5 Curcuma longa L 7

Figure 2.6 Curcuma zedoaria 8

Figure 2.7 Curcuma aromatic 8

Figure 2.8 Distribution of various compound types in Curcuma species Data were obtained from literature published in 1815–2014 (Sun et al., 2016) 9

Figure 2.9 Structural formula of demethoxycurcumin and bisdemethoxycurcumin 10

Figure 2.10 The schematic for Clevenger-type apparatus (S.H.Jain & G.Ravikumar, 2010) 18

Figure 2.11 The schematic apparatus for Steam distillation (Rassem et al., 2016) 19

Figure 2.12 Extraction of essential oils with solvents ("A Comprehensive Guide to Essential Oil Extraction Methods," 2017) 20

Figure 2.13 Cold pressing method (Rassem et al., 2016) 21

Figure 2.14 Soxhlet extraction (Rassem et al., 2016) 22

Figure 2.15 Microwave-assisted hydro-distillation (Rassem et al., 2016) 23

Figure 2.16 Supercritical Fluid Extraction (SFE) (Rassem et al., 2016) 24

Figure 2.17 Extraction of essential oils by steam distillation ("A Comprehensive Guide to Essential Oil Extraction Methods," 2017) 25

Figure 3.1 Diagram of the process of recovering turmeric leaf essential oil 34

Figure 3.2 Experimental design for recovering turmeric essential oil 35

Figure 3.3 Pre-treatment leaves were investigated with different times 36

Figure 4.1 Effect of different time on essential oils content during distillation 42

Figure 4.2 Effect of different leaf sizes on essential oils during distillation 43

Figure 4.3 Effect of different time of Steam pre-treatment on essential oils content during distillation 44

Figure 4.4 Effect of different time of Ultrasound pre-treatment on essential oils content during distillation 45

Figure 4.5 Effect of different time of Microwave pre-treatment on essential oils content during distillation 46

Figure 4.6 Effect of different pre-treatments of leaves on density of essential oils from turmeric leaves 49

Figure 4.7 Effect of different pre-treatments of leaves on viscosity of essential oils from turmeric leaves 50

Figure 4.8 The effect of turmeric leaves oil concentration from different material treatment methods on microorganism diameter of S aureus during 7 days of incubation 54

Figure 4.9 The effect of turmeric leaves oil concentration from different material treatment methods on microorganism diameter of E.coli during 7 days of incubation 55

Figure 4.10 Half maximal inhibitory concentration (IC50) of 4 different types of essential oil for Staphylococcus aureus and Escherichia coli 59

LIST OF TABLES

Table 3.1 Tools and equipment used 33 Table 3.2 Chemical substances and origin 34 Table 4.1 Total essential oils content in the material 47 Table 4.2 Effect of different pre-treatments of leaves on color characteristic of essential oils from turmeric leaves 47 Table 4.3 Effect of different pre-treatments of leaves on acidity index of essential oils from turmeric leaves 51 Table 4.4 Effect of different pre-treatments of leaves on saponification index of essential oils from turmeric leaves 51 Table 4.5 Effect of different pre-treatments of leaves on ester index of essential oils from

turmeric leaves 52 Table 4.6 Hedonic scale sensory evaluation results 52 Table 4.7 Main component of turmeric leaf essential oil with ultrasound pretreatment and no pretrearment 54 Table 4.8 The effect of turmeric leaves oil concentration from different material treatment

methods on microorganism diameter of S aureus and E.coli after 7 days of incubation 56 Table 4.9 The effect of turmeric leaves oil concentration from different material treatment

methods on growth inhibition (%) of S aureus and E.coli after 7 days of incubation 57

ABSTRACT

Essential oil was extracted from the turmeric leaf of six size namely 1mm, 5mm, 10mm, 15

mm, 20mm, whole leave and three pretreatments namely steaming, ultrasound treating, microwaving using Clevenger apparatus All the four species yielded significantly different essential oil The mean essential oil content of 0.450, 0.413, 0.367, 0.353, 0.310 and 0.343 (ml) was obtained from 1mm, 5mm, 10mm, 15 mm, 20mm, whole leave, respectively Particle size of leaf was found to have significant influence on oil yield The highest mean essential oil content

of 0.483, 0.500 and 0.487 was obtained from steaming, ultrasound treating, microwaving, respectively The GC-MS analysis for composition of the essential oils found 44 and 36 volatile compounds in the essential oils from non-treated and ultrasound-treated leaves, respectively In addition, α - Phellandrene was found as the most dominant compound in the essential oil samples (45.6-51.9%) followed by α-Terpinolene (9.5-11.9%) and Eucalyptol (8%) Thus the use of ultrasound treating not only affected the antimicrobial activity but also impacted the composition

of essential oil from turmeric leaves

Keyword: Essential oil, turmeric leave, pretreatment, steam distillation, antimicrobial

Chapter 1: INTRODUCTION 1.1 Introduction

Turmeric (Curcuma longa L.) is a plant that has been grown very popular in Vietnam and

some Asian countries for a long time to be used as a medicine and also in food The rhizome of the turmeric plant has been utilized as a material for functional foods; however, other components of the plant, such as the leaves, which are typically discarded as a waste product, have their own unique applications due to the presence of curcumin and other bioactive components Furthermore, turmeric leaves have a huge volume and surface area, both of which contribute to the plant's exceptional value for use in industrial applications as a rich source of food (Choi & Lee., 2014) Studies have been conducted to explore the physicochemical properties of the turmeric leaf extract in order to illustrate the extract's functional effects, which include whitening, cosmeceutical, skin immunity, anti-inflammatory, and antioxidant activities (Kim, Lim, & Lee., 2014) These effects are mostly caused by curcumin, which is found in turmeric leaves, as well as phenolic chemicals and flavonoids

In Vietnam, although there have been many studies related to the extraction of active ingredients from turmeric rhizome, there has been no research on extraction of the beneficial compounds from turmeric leaves Therefore, after harvesting turmeric, almost all the leaves are discarded Turmeric leaves are not employed in industrial domains despite their functional characteristics due to a lack of safety and legal basis and turmeric leaf research is poor and restricted to explain their properties and functions Because of these factors, turmeric leaves are only utilized as feed for stock in certain regions and disposed as a waste with vast disposal costs (Choi & Lee., 2014) Thus, if actively researching to discover and use new materials from turmeric leaves, a source of waste, is considered as a driving force for the development of new industries with high added value From that, investigating the effects of extraction in order to determine the appropriate parameters to increase the yield of essential oil, increase the quality of essential oils and produce products with high biological activity is very urgent

In this study, the effect of leaf size, extraction time and different pre-treatment methods of leaves on the extraction efficiency of essential oil, color characteristic, viscosity, density, sensory and antibacterial activity from essential oil of turmeric leaves were investigated to provide suitable parameters that can be applied to improve the production efficiency of related products

1.2 Research content

The research content is classified into three major parts as shown below:

- Recovering of fresh turmeric leaves by hydrodistillation to prepare essential oils

- Investigating factors affecting the yield and quality of the essential oil from turmeric leaves using hydrodistillation

- Analyzing physicochemical properties, chemical composition, sensory properties and

antimicrobial activity of essential oil from turmeric leaves

1.3 Research aims

Aim 1

To optimize the recovering efficiency of essential oils and quality of essential oils from turmeric leaves

Expected outcomes: Effects of conditions (time, leave size and pre-treatment of the leaves)

on the extraction efficiency and quality parameters of the essential oil obtained from the turmeric leaves by using hydrodistillation

Recovering essential oil

- Hydrodistillation method with Clevenger apparatus

Optimizing the recovering of

The recovering conditions have a considerable impact on the efficiency with which essential oil can be recovered from turmeric leaves, and the application of material treatment methods has the potential to increase the amount of essential oil that can be recovered

There is a significant difference in physicochemical quality between essential oil from material non-treated and material treated

Essential oils using material treated have higher antimicrobial activity than essential oils recovered by material non-treated

Chapter 2: LITERATURE REVIEW2.1 Overview of turmeric and turmeric leaves

2.1.1 Origin

In India's ancient Vedic culture, a spice known as turmeric played both a role in the kitchen and in religious rituals During this time, turmeric was employed for both culinary and spiritual purposes It is likely that it arrived in China around the year 700 A.D., in East Africa around the year 800 A.D., in West Africa around the year 1200 A.D., and in Jamaica in the eighteenth century (Aggarwal, Prasad, & B., 2011) In the year 1280, Marco Polo wrote about this seasoning, marveling at a vegetable that had properties that were so similar to those of saffron Turmeric has been used for therapeutic purposes in South Asia for a very long time, as evidenced

by Sanskrit medical treatises as well as the Ayurvedic and Unani medical systems And use of an ointment that contains turmeric is suggested in the Ayurvedic Compendium written by Susruta about the year 250 B.C to alleviate the consequences of consuming poisonous food

Since ancient times, Indians have been familiar with turmeric's medicinal potential as an aromatic plant Many researchers in the fields of science and history believe that the origin of turmeric can be traced back to South Asia They claim that it was from this region that turmeric made its way to the countries of Southeast Asia and the Pacific Islands, where it is now farmed

As early as the fifth century A.D., there is documentary evidence that wild turmeric cultivation existed in the forested parts of Java, Indonesia The applications of turmeric were described in Sanskrit manuscripts that date back to the fifth and sixth centuries AD (Nair, 2019)

Around the world, people refer to turmeric by a variety of other names Many people believe that the name "turmeric" came from the Latin word "Terra Meritta," which meant sacred soil This theory is supported by linguistic evidence (Aggarwal et al., 2011) Saffron is a frequent name for turmeric in many regions of the world It is also possible that the word turmeric got its name from the metallic appearance of the spice In India, it is referred to by a variety of names depending on the language spoken, including Manjal in Tamil and Malayalam, Arishina in Kannada, Pasupu in Telugu, Haladi in Sanskrit and Hindi, and Haldi in a number of other languages spoken in North India

2.1.2 Characteristic

Turmeric (Curcuma longa L.) is a rhizomatous herbaceous perennial plant that is native to

the tropical regions of South Asia It is a member of the ginger family, Zingiberaceae, and produces turmeric as a byproduct (Aggarwal et al., 2011) There are approximately 110 species that belong to the genus Curcuma, which is one of the most significant members of the Zingiberaceae family Many of these species have been demonstrated to have a variety of applications (Sasikuma, 2005)

After approximately four or five months from the time of planting, turmeric will begin to flower To reach the stage of blossoming, turmeric flowers need seven to eleven days, and the blossoming process typically lasts for another seven to eleven days after that (Patnaik, S., B.C.,

& Mohapatra, 1960) The flowering season for C longa extends from September to December, and the specific duration of flowering ranges from 118 to 143 days following planting For optimal growth, the turmeric plant requires temperatures ranging from 20 to 30oC and a substantial amount of annual precipitation

Turmeric is a perennial plant from 60 centimeters to 1.5 meters high It has thickened rhizomes, finger-shaped, that is to say, underground stems with several buds, and grows horizontally Plants are gathered annually for their rhizomes, and are reseeded from some of those rhizomes in the following season The length of the leaf blades typically ranges from 37 to

38 centimeters, with a maximum length of 50 centimeters possible The green leaf stems are nearly one meter in height The petiole is thin but it widens as it gets closer to the blade's base (K.Maheshwari, K.Singh, JayaGaddipati, & C.Srimal, 2006)

Because it contains a lot of starch, the rhizome serves as a source of nutrition for the plant; in addition, it is the component that is utilized in culinary preparation The tuberous rhizome, from which turmeric is extracted, has a rough and segmented skin Turmeric is derived from this rhizome Underneath the foliage, in the ground, the rhizomes develop into their mature state They have an exterior that is yellowish brown and an interior that is dull orange The main rhizome is pointed or tapered at the distal end and measures 2.5–7.0 cm (1–3 inches) in length and 2.5 cm (1 inch) in diameter, with smaller tubers branching off

Figure 2.1 (a) Whole plant, (b) rhizomes of C.longa

In Vietnam, there are currently 27 species (Leong-Škorničková, Lý, & Nguyễn, 2015) scattered from North to South Some varieties are grown and used a lot in food processing as well as medicine in Vietnam:

Curcuma alismatifolia – Gagnep

Flowering season is around June and July It is shade tolerant plant, grows under the canopy

of moist forests, along the slopes In Vietnam, this plant is distributed in Kon Tum, Tay Ninh, An Giang

Figure 2.2 Curcuma alismatifolia

Curcuma kwangsiensis - S G Lee & C F Liang

Flowering season is from March to July It is a hygrophyte plant, shade tolerant plant, lots of humus Grows among lawns and shrubs, along forest trails, along small streams, along fields Distributed in Kon Tum (Dak Glei; Dak Choong)

Figure 2.3 Curcuma kwangsiensis

Curcuma cochinchinensis – Gagnep

Flowering season in August It is a hygrophyte plant, growing along the trails, along streams, under the canopy of the forest Distributed in Kon Tum, Gia Lai, Dak Lak

Figure 2.4 Curcuma cochinchinensis

Curcuma longa L

Flowering season from July to August It is a hygrophyte plant, shade tolerant plant, grows better under the canopy Commonly grown in Kon Tum, Gia Lai, Dak Lak, Lam Dong

Figure 2.5 Curcuma longa L

Curcuma zedoaria - (Berg.) Rosc

Flowering season from April to June It is shade tolerant plant, grows under the canopy of moist forests, along streams, along trails, or planted in gardens, along swidden fields Grows wild and is grown in many places in Tay Nguyen

Figure 2.6 Curcuma zedoaria

Curcuma aromatic - Salisb

Flowering season from April to June The tree grows under the canopy of trees or in large clusters in bright places along roads and streams Grows and grows wild in many places in Vietnam: Lam Dong (Bao Loc)

Figure 2.7 Curcuma aromatic

2.1.3 Chemical composition and application

2.1.3.1 Chemical composition

At this point, at least 235 compounds, the majority of which are phenolic compounds and terpenoids, have been identified as coming from the species These compounds include 22 diarylheptanoids and diarylpentanoids, 8 phenylpropene and other phenolic compounds, 68 monoterpenes, 109 sesquiterpenes, 5 diterpenes, 3 triterpenoids, 4 sterols, 2 alkaloids, and 14 other compounds (S Li et al., 2011)

The amounts of curcuminoids found in turmeric rhizomes change significantly depending on the variety, geographical location, source, and growing conditions On the other hand, the essential oils found in turmeric rhizomes are significantly different depending on both the variety and the geographical location (S Li et al., 2011)

Figure 2.8 Distribution of various compound types in Curcuma species Data were obtained

from literature published in 1815–2014 (Sun et al., 2016)

Turmeric has a moisture content of 8.92%, a crude fiber content of 4.60%, an ash content of 2.85%, a fat content of 6.85%, a crude protein content of 9.40%, and a carbohydrate content of 67.38% By eliminating potential carcinogens from the body and preventing the absorption of excessive cholesterol, fiber helps to keep the digestive system of the consumer clean In addition

to bulking up food, fiber serves as a deterrent to overindulging in starchy carbs, which can lead

to metabolic issues like high cholesterol and diabetes (Okwu & Josiah, 2006)

Curcumin, essential oil (3-5%), fat, Tumerin (protects DNA), Ukonan-A (whitened activated blood cells), Ukonan-D (anti carcinogenic), vitamin A, carotenoids, and minerals are all found in the turmeric composition study A rough estimate of the turmeric's composition is: 8.92% moisture, 2.85% ash, 4.60% crude fiber, 6.85% fat, 9.40% crude protein, and a whopping 67.38% carbohydrate This indicates that it could be a healthy source of protein and carbs Minerals in turmeric range from 0.05 to 0.20 percent of the total nutrient content of the herb (Payton, Sandusky, & Alworth, 2007) Strong bones, muscle contraction and relaxation, blood pressure reduction, and hemoglobin synthesis maintenance can all be achieved with regular consumption of turmeric plants Iron deficiency anemia can be treated with turmeric Because the iron in the extract aids in the formation of hemoglobin (DieterPeschel, RamonaKoerting, & NorbertNass, 2007)

An average turmeric plant has about 0.76% alkaloid, 0.45% saponin, 1.08% tannin, 0.03% sterol, 0.82% phytic acid, 0.40% flavonoid, and 0.08% phenol These are the normal concentrations seen in turmeric plants To treat hypertension-related headaches, colds, and

persistent migraines, turmeric can be utilized because it contains alkaloids (0.76 percent) Antioxidant saponins, flavonoids, and tannins in turmeric plants have been shown to increase sexual hormones, lower cholesterol, prevent damaging cytotoxins, and decrease inflammation (Hewlings & Kalman, 2017) Turmeric has been shown to have antioxidant effects and is used to treat diarrhea and dysentery

Curcumin, demethoxycurcumin and bisdemethoxycurcumin collectively known as curcuminoids (3-6%) are major polyphenolic compounds in turmeric rhizomes

Figure 2.9 Structural formula of demethoxycurcumin and bisdemethoxycurcumin

2.1.3.2 Nutritional value

a Turmeric flowers

The nutritional value of turmeric blossoms has not been investigated to any significant degree The blossoms, similar to other types of flowers, may contain fiber, which helps to stimulate the digestive tract, and vitamin C, which helps to boost the immune system Curcumin,

a compound with antioxidant-like and anti-inflammatory properties, is present in turmeric flowers Turmeric flowers are the source of this compound It is common practice in the traditional medicine of Southeast Asia to use turmeric flowers as a postpartum remedy to aid in the recovery of the mother's body These flowers are also thought to have anti-aging properties

by free radicals It's also thought that curcumin can help the digestive system It is believed that rhizome has around forty naturally occurring chemicals, in addition to the vitamins and minerals

it already has a reputation for having

2.1.3.3 Application

a Culinary

Foods that contain turmeric have a scent similar to that of mustard, an earthy flavor, and a flavor that is pungent and slightly bitter Turmeric is one of the major ingredients in many Asian dishes Although it is most commonly found in savory preparations, you may also find it in some

sweet preparations, such as the cake sfouf Patoleo is a type of special sweet food that is prepared

in India using turmeric leaf The leaf is layered with rice flour and a coconut-jaggery mixture, after which the leaf is folded over, sealed, and steamed in a chondr, which is a traditional Indian cooking vessel To get its characteristic golden yellow hue, turmeric is most commonly utilized

as a powder made from ground rhizomes It can be found in a wide variety of products, including canned beverages, baked goods, dairy products, ice cream, yogurt, yellow cakes, orange juice, biscuits, cereals, sauces, and gelatin Curry powders almost always include it as a primary component Like ginger, turmeric can also be utilized in its fresh state, despite the fact that its powdered, dried form is the more common application It is used in a wide variety of ways in the cuisine of East Asia, such as in a pickle that includes huge pieces of fresh soft turmeric

South Asian and Middle Eastern cuisines both make extensive use of turmeric as a seasoning ingredient

As a food coloring, curcuma longa (turmeric) has been designated with the number E100 When mixed with annatto, turmeric has been put to use as a coloring agent for a wide range of cuisines (E160b) In addition to being used to impart color to a wide variety of prepared mustards, canned chicken broths, and other foods, turmeric is commonly employed because it is

a more cost-effective alternative to saffron However, it can be used only for certain foodstuffs and is for short‑term storage This is due to its light sensitivity and degradation on exposure to heat, chemical oxidants, and alkaline conditions

b Dye

The golden yellow hue of turmeric is due to an ingredient called curcumin In addition to that, an oil that easily evaporates and is orange in color is present The bark fabric of Polynesia and Micronesia, as well as the faffia ikats made by the Sakalva people of northwest Madagascar, are all dyed with turmeric Also, the robes worn by Burmese Buddhist monks are dyed with turmeric Turmeric was used as a resource for dying textiles produced in China throughout the Ming and Qing dynasties, according to research on those dynasties' textile production (Zhang, Corrigan, MacLaren, Leveque, & Laursen, 2007) During the later part of the Edo period, turmeric was utilized in the manufacturing of beni itajime shibori This was done either to dilute

or replace the more expensive safflower dyestuff (1603-1867)

c Indicator

A sheet of paper that has been steeped in a turmeric tincture and then allowed to dry is referred to as turmeric paper, curcuma paper, or Curcumapapier in German literature Other names for turmeric paper include turmeric paper and curcuma paper In the process of chemical analysis, it serves as both an acidity and an alkalinity indicator (Remadevi, Surendran, & Kimura, 2007) Paper turns a yellow color in acidic and neutral solutions within a pH range of 7.4 to 9.2; however, it turns a brown to reddish-brown color in alkaline solutions (Berger & Sicker, 2008)

d Medicine

Rheumatoid arthritis, chronic anterior uveitis, conjunctivitis, skin cancer, chicken pox, small pox, wound healing, urinary tract infections, and liver diseases are some of the conditions that turmeric is used to treat as a herbal therapy (VP, P, & SC, 1988) It is also used for digestive disorders; to reduce flatus, jaundice, menstrual difficulties, and colic; for abdominal pain and distension; and for dyspeptic conditions including loss of appetite, postprandial feelings of fullness, and liver and gallbladder complaints All of these conditions can be treated with this medication Carminative, anti-inflammatory, antimicrobial, and antimicrobial effects are all carried out by it The intestine, the bowels, and the colon are the primary clinical targets of turmeric In the intestine, turmeric is used for the treatment of diseases such as familial adenomatous polyposis; in the bowels, turmeric is used for the treatment of inflammatory bowel disease; and in the colon, turmeric is used for the treatment of colon cancer (Naganuma, Saruwatari, Okamura, & Tamura, 2006)

e Comestology

Since women have always applied turmeric to their skin as a beauty treatment, it is possible that turmeric was the earliest known cosmetic It is supposed to slow the growth of facial hair, lessen the appearance of acne, and enhance complexion (Shaffrathul & Karthick, 2007) According to the authors' observations, a lot of ladies in Tamil Nadu still wash their faces with turmeric before every single one of their showers Products designed for the care of the skin have made use of the color yellow Tetrahydrocurcumin is a hydrogenated derivative of curcumin that has an off-white color and is applied topically to the skin to act as an antioxidant When used with moisturizers, it has the potential to prevent the rancidity of lipids In the field of cosmeceuticals, curcuminoids have the potential to act as antioxidants, anti-inflammatory agents, and skin whitening agents In‑vitro curcuminoids inhibit collagenase, elastase and hyaluronidase

It has been observed that applying curcumin gel for an extended period of time, such as six months, can improve the appearance of photodamaged skin conditions such as pigmentary changes, solar elastoses, actinic poikiloderma, solar lentigines, and actinic keratosis It is possible for it to encourage apoptosis in cells that have DNA damage (MD, FRACP, FACD, & FAAD, 2010) It is being considered as a potential environmentally friendly hair coloring agent right now There is a possibility that the essential oils will find use in the soap, cosmetic, and perfume industries (Sasikuma, 2005)

2.2 Overview of essential oils

2.2.1 Definition

Essential oils (EOs) are mixtures of organic compounds with the common property of being volatile, aromatic, and derived mainly from certain parts of plants (such as seeds, roots, tubers, bark, flowers, leaves, fruit, oil, sap) (Kumari et al., 2014) Essential oil can be compared to the sap that flows through a tree; as a result, it possesses energy and is 100 times more potent than dried herbs

Plants that are rich in essential oils can be found all over the natural world The climate and the conditions of the soil both have an effect on the amount of essential oil that the tree contains Essential oils are found in higher concentrations on tropical plant life compared to their

temperate counterparts Even within a single plant, different portions might have quite diverse essential oil compositions as well as essential oil concentrations In addition, the quantity of essential oil produced is influenced by the conditions in which the plant was grown, as well as the techniques used for harvesting, preserving, and extracting the oil In terms of the distribution

of essential oils, there are a disproportionately large number of plants that belong to the camphor family, the lily family, the orange family, the myrtle family, and the canola family respectively Essential oils can be found in several sections of the plant, including the flowers (such as persimmon, jasmine, orange, and lemon), the leaves (such as eucalyptus, mint, and basil), the stems of the tree (such as sandalwood), the bark (such as cinnamon), and the roots (such as thyme and oregano) (ginger, turmeric, cardamom, etc.) Essential oils can be readily available in plants, or they might be generated only under specific conditions At that point, essential oils are not typical components of the plant; rather, they are a byproduct that can only be produced under specific conditions and after certain plant components have perished

Classification of EOs:

- Pure, natural essential oils:

An essential oil is considered to be pure and natural if it has not been adulterated in any manner and has been extracted from the volatile and aromatic chemicals that are found naturally within the plant (ReThinkOil, 2020) In order to extract the active plant ingredients and produce

a product that is concentrated in essential oil, the industry makes use of a wide array of extraction methods and processes The distillation of steam, the extraction of CO2, and the use of solvents are typical examples of these extraction procedures Essential oils that are 100% natural and pure are extracted without using any sort of standardization from the volatile aromatic chemicals that are naturally present in the plant

- Standardized essential oils:

Essential oils that are standardized have been changed from their original condition in order

to preserve a consistent quality and/or to specifically boost the concentration of certain naturally existing components This action can be carried out at any point in time before, during, or after the extraction process, and it is not inherently dishonest (ReThinkOil, 2020)

2.2.2 Origin and development of essential oils

Essential oils have been known to mankind for a very long time; in fact, people have been using plants that contain essential oils in their dried form since ancient times Essential oils saw widespread use across a variety of industries and applications from the 17th through the 19th centuries, particularly in the fields of medicine and cosmetics The essential oil production sector has undergone progressive development over the course of the 20th century and into the early years of the 21st century, developing in tandem with the progression of mankind as well as the advancement of science and technology Products are essential to human existence and find widespread use in a variety of businesses, including those related to food, flavoring, cosmetics, and medications (Kubeczka & Karl-Heinz, 2015)

2.2.3 Physical properties and chemical compositions of essential oils

2.2.3.1 Physical properties

Essential oils usually exist in liquid form at room temperature, fragrant, rarely color, except for essential oils containing aluzen which are green Essential oils have low density compared to water, high refractive index Essential oils are volatile, essential oils are slightly soluble in water but give the water a fragrant aroma, essential oils are mixtures so there is no certain boiling point, essential oils are soluble in alcohol, ethers, organic solvents and fats

• Physical properties:

To determine the physical properties of essential oils, it is common to determine indexes such as density, refractive index, solubility in alcohol 90° at 25°C, boiling point, polar rotational yield, and color

Most essential oils are less than 1 by weight, so they are usually lighter than water However, there are also some essential oils with specific gravity larger than water (such as cinnamon essential oil, clove essential oil, etc.)

Essential oils are insoluble or very slightly soluble in water, but they dissolve well in most organic solvents such as ether, alcohol Although the chemical composition of each essential oil

is different, they generally have a boiling point of about 80°C to 150°C, are volatile, and have a pleasant aroma

In terms of color, essential oils are usually colorless or pale yellow A small number of essential oils have color (e.g mugwort oil is blue, cinnamon essential oil is dark brown) due to the presence of colored compounds that are attracted to the essential oil during extraction (e.g green due to chlorophyll, yellow due to carotenoids, etc.) The smell and taste of essential oils are mainly caused by oxidized components

Monoterpenes: Monoterpenes are the most representative elements and can make up as

much as 90 percent of several essential oils They are present in practically all essential oils and can be found in them (Zuzarte & Salgueiro, 2015) Monoterpenes have the molecular formula of open-chain C10H16 Typically, miaxene, oximene, are present in the essential oil of laurel flowers

Miaxene Oximen

Monoterpenes are antiseptic and tonic in nature They have good air filtration Monoterpenes are present in most essential oils

Sesquiterpenes: Although not as volatile as Monoterpenes, the typical linear and cyclic

sesquiterpenes are farnesene, Zingiberene (ginger essential oil)

Thymol Estragol Eugenol

Disinfectants are mostly found in plants, stimulating the body, and phenols are effective when used in small doses However, large doses can be a neurotoxin and may cause skin irritation

Alcohol: Some important alcohols extracted from common essential oils such as: Menthol,

- Terpineol, Geraniol, etc

Menthol - Terpineol Geraniol

Many alcohols are present in essential oils As antiseptic, antibacterial, anti-fungal and antibiotic, very good tonic for the system | nervous system and stimulates the immune response

in the body

Ester: The esters evaporate quickly and give flavor to the fragrance Some esters present in

essential oils: ethyl anthranilate, benzyl acetate, etc

Ethyl anthranilate Benzyl acetate

Esters have antispasmodic, antibacterial and anti-inflammatory properties, and applying the ester gently on the skin will aid in the rebalancing of the nervous system effectively

Aldehydes: There are many aldehydes in essential oils, but now all aldehydes are obtained

through chemical synthesis Only aldehydes such as cuminic, citral and citronellal aldehydes have been extracted from natural materials

Cuminic aldehyde Citronellal aldehydes