CHAPTER ONE

INTRODUCTION

1.1 Background of the Study

Sesamum indicum L. (family: Pedaliaceae) is an annual lowering shrub known as

Sesame or Benne, 40–75 cm in height, with opposite, broad lanceolate leaves and

white, blue, or purple colored, tubular, lowers. It is widely naturalized in tropical

regions around the world and is cultivated for its edible seeds, which grow in pods.

Sesame fruit pod is a capsule, normally pubescent; rectangular in section, and

naturally splits open (dehisces) to release the seeds by splitting along the septa

from top to bottom (Martin et al., 2017). Sesame seeds occur in small size about 3

to 4 mm long by 2 mm wide and 1 mm thick, of-white, buf, gold brown, reddish

gray and black color. Sesame has one of the highest oil contents of any seed with a

rich, silly lavor. It is a common ingredient in cuisines across the world (Ogasawara

et al., 2018). Sesame seeds have been generally used in culinary as well as

traditional medicines for their nutritive, protective, and curative properties. Sesame

is an important source of phytonutrients like Omega-6 fatty acids, lavonoid

phenolic anti-oxidants, vitamins, dietary iber and other bioactive health promoting

components (Abou-Gharbia et al., 2020). Investigations on sesame reveals the

presence of carboxylic acids and phenolic groups in essential oils especially some

of the most potent antioxidants such as sesamol, sesamolin, sesamin, glycerol

esters of diferent fatty acids, lignans and myristic acid (Kato et al., 2018). Several

beneficial effects of the sesame oil are already reported in Ayurveda, an ancient

Indian medical literature. Seeds of the plant have potential positive health benefits

and contain components with different biological actions. Its medicinal, industrial

and pharmaceutical characteristics are clearly explored in a recent investigation

(Kato et al., 2018). In present study, extraction of sesame seeds will be carried out

and its antioxidant activity and phyto constituents were determined by Gas

Chromatography-Mass analysis (GC/MS).

1.2 Statement of the Problem

Sesame production has been an integral part of agricultural production in Jigawa

State. A large number of farming households in the state engage in production of

the crop. There is growing concern for provision of effective and sustainable

agricultural extension services to majority of smallholder farmers in whose hands

the bulk of agricultural production lies. The smallholder farmers are constrained by

many problems including those of poor access to modern inputs and credit, poor

infrastructure, inadequate access to markets, land and environmental degradation,

and inadequate research and extension services. These problems have caused low

agricultural production and a continuous rise in the country’s import bill on food

items over the years in spite of the fact that the country has the human and natural
resources to produce sufficient quantity of the food need of the people (Egwemi

and Odo, 2013).

1.3 Aim and Objectives of the Study

The aim of the study is to examine the phytochemical profiling and GC-MS

analysis of ethanol extract from from sesamum indicum. The objectives to be

carried out are:

1.4 Justification of the Study

Sesame is one of Nigeria’s export crops and is a major cash crops cultivated by

smallholder farmers. Encouraging farmers in its production and providing them

with better production technologies and market information for their produce can

be considered as a way of improving their livelihoods. This will be more

appropriate if a study, of this nature assesses the key areas of production that needs

attention. To this effect, the findings of the study would be of benefit to the

government through improvement in output of sesame and hence increased foreign

exchange. The findings would also be of benefit to Non-governmental

Organizations (NGO) and Developmental partners through fine tuning how best to

take developmental interventions to farmers. Extension workers will also benefit

from identifying the challenges of delivering technologies to farmers. Finally

research students will also find the findings of the study beneficial by using it as a

reference material for future research work.

 CHAPTER TWO

LITERATURE REVIEW

2.1 Sesame (Sesamum indicum L.)

Sesame (Sesamum indicum L.), otherwise known as sesamum or benniseed,

member of the family Pedaliaceae, is one of the most ancient oilseeds crop known

to mankind. Sesame plays an important role in human nutrition. Most of the

sesame seeds are used for oil extraction and the rest are used for edible purposes

(El Khier et al, 2008). Sesame is grown primarily for its oil-rich seeds. Before

seeds were appreciated for their ability to add nutty flavour or garnish foods, they

were primarily used for oil and wine (Ghandi, 2009). After the extraction of oil, the

cake is mostly used for livestock feed or often as manure. Its colour varies from

cream-white to charcoal-black but it is mainly white or black. Other colours of

some sesame seed varieties include, yellow, red or brown (Naturland, 2002). In

Nigeria, the notable colours for sesame seed are white, yellow and black (Fariku et

al., 2007). The lighter varieties of sesame which are considered to be of higher

quality are generally more valued in the West and Middle East, while both the pale

and black varieties are prized in the Far East. There are numerous varieties and

ecotypes of sesame adapted to various ecological conditions (Nzioku et al., 2010).

The major world producers include India, Sudan, China and Burma (who

contribute about 60% of the total world production) (El Khier et al, 2008). It is also
one of main commercial crops in Nigeria, Sudan and Ethiopia (www. nutrition and

you). Sesame is an important crop to Nigerian agriculture: it is quite extensively

cultivated especially in Northern Nigeria. It yields in relatively poor climatic

conditions, and it is widely used within Nigeria. More so, it is an important

component of Nigeria’s agricultural exports (Chemonics, 2002).

Fig 2.1: Sesame seed (Nzioku et al., 2010)

Sesame seed is rich in fat, protein, carbohydrates, fibre and some minerals. The oil

seed is renowned for its stability because it strongly resists oxidative rancidity even

after long exposure to air (Global AgriSystems, 2010). The oil fraction shows a

remarkable stability to oxidation. This could be attributed to endogenous

antioxidants namely lignins and tocopherols (Lee et al., 2008). The seed is rich in

protein and the protein has disable amino acid profile with good nutritional value
similar to soybean (NAERLS, 2010). The chemical composition of sesame shows

that the seed is an important source of oil (44-58%), protein (18-25%),

carbohydrate (~13.5%) and ash (~5%) (Borchani et al., 2010). Sesame seed is

approximately 50 percent oil (out of which 35% is monounsaturated fatty acids and

44% polyunsaturated fatty acids) and 45 percent meal (out of which 20% is

protein) (Hansen, 2011).

2.2 History

Sesame seeds are the seeds of the tropical annual Sesamum indicum. The species

has a long history of cultivation, mostly for its yield of oil. The oil plant has been

grown since the beginning of arable cultivation, and originates from the dry bush

savannah of tropical Africa, and spread from there to India and China, where it is

still widely cultivated (Naturland, 2002). The original area of domestication of

sesame is obscure but it seems likely to have first been brought into cultivation in

Asia or India (www.nigeriamarkets.org). Archeological records indicate that it has

been known and used in India for more than 5,000 years and is recorded as a crop

in Babylon and Assyria some 4,000 years ago (Borchani et al., 2010). Sesame was

cultivated during the Indus valley civilization and was the main oil crop. It was

probably exported to Mesopotamia around 2500 BCE and was known in Akkadian

and Sumerian as 'ellu'. Prior to 600 BC, the Assyrians used sesame oil as a food,
salve, and medication, primarily by the rich, as the difficulty of obtaining it made it

expensive. Hindus used it in votive lamps and considered the oil sacred.

2.3 Production of sesame seed

Global production of sesame seed is estimated by FAO at 3.15 mn tonnes per year

(2001) having risen from 1.4 mn tonnes in the early 1960’s. Sesame is grown in

many parts of the world on over 5 million acres (20,000 km2). The largest

producer of the crop in 2007 was India, China, Myanmar, Sudan, Ethiopia, Uganda

and Nigeria. Seventy percent of the world's sesame crop is grown in Asia, with

Africa growing 26% (Hansen, 2011) The largest producers are China and India,

each with an annual harvest around 750,000 tonnes followed by Myanmar

(425,000 tonnes) and Sudan (300,000 tonnes). These figures are only rough

estimates of the situation as sesame is a smallholder crop and much of the harvest

is consumed locally, without record of the internal trade and domestic processing.

Nigeria has a great market potential for sesame seed production for domestic and

export markets noting that the production figures of the commodity has been on a

steady increase since 1980, reaching 67000 MT by 1997 and was estimated to

reach 139, 000 MT by the year 2010, according to the federal ministry of

agriculture and natural resources (Joseph, 2009). This is agreement with the 2008

annual report of the Central Bank of Nigeria which states there has been a rise in
production of sesame seed from 98,000,000 to 152,000,000 kg from 2003 to 2007

(CBN, 2009).

Out of the estimated 3.5million hectares of Nigeria’s arable land suitable for the

growth of sesame seed, only 300,000 is currently used for the crop. However

average yield of crop is about 300kg/ha which is 4 times lower than the average

yield of other seed crops eg groundnut and soybeans. In major production zones in

the country, it is used in traditional food recipes and snacks rather than for export

purposes (NAERLS, 2010). Nigeria was the largest supplier to the Japanese

market, the world’s largest import market for sesame (Chemonics, 2002). Thus, the

potentials for beniseed production in Nigeria is high since Japan, as well as Taiwan

and Korea, generate global demand and offer opportunity for Nigerian growers.

Nigeria has a 6% share of the $600 million global market for sesame seed

(Nigeria’s Harvest, 2009). Sesame was widely grown in Middle Belt, Northern and

Central Nigeria as a minor crop initially in 1974 when it became a major cash crop

in many Northern States eg Benue, Kogi, Gombe, Jigawa, Kano, Nasarawa,

Katsina, Plateau, Yobe and Federal capital Territory (NAERLS, 2010). Sesame is

commonly grown by smallholder farmers. The major producing areas in order of

priority are Nasarawa, Jigawa and Benue States. Other important areas of

production are found in Yobe, Niger, Kano, Katsina, Kogi, Gombe and Plateau

States.
2.4 Growth conditions

Sesame has important agricultural attributes: it is adapted to tropical and temperate

conditions, grows well on stored soil moisture with minimal irrigation or rainfall,

can produce good yields under high temperatures, and its grain has a high value

(Bennet, 2011). Sesame is found growing in most tropical, sub tropical and

southern temperate areas of the world (Ghandi, 2009). However it is now

cultivated around the dry tropics between the latitudes of 40° N and S. It is

scarcely cultivated in the USA or Europe, not only because of climate but also

because of the low returns per unit area (Chemonics, 2002). It has been reported to

be a typical crop for small farmers in the developing countries (Bennet, 2011).

This is because it has deep roots and is well adapted to withstand dry conditions. It

will grow on relatively poor soils in climates generally unsuitable for other crops,

and so it is widely valued for its nutritional and financial yield from otherwise

inclement areas. It is well suited to smallholder farming with a relatively short

harvest cycle of 90 –140 days allowing other crops to be grown in the field

(Nigeria’s Harvest, 2009) and is often intercropped with other grains. This makes it

favourable to Nigerian farmers and production can thus be sustained by small scale

farmers with minimum management with an average yield of 700 kilograms per

hectare (Nigeria’s Harvest, 2009). Sesame world production areas have remained

generally stable over the years, but in some countries the crop is being
marginalized (Bennet, 2011). Competition from more remunerative crops and a

shortage of labour have pushed sesame to the less fertile fields and to areas of

higher risk. Left unchecked, sesame production may decrease in the foreseeable

future. Sesame cultivation can be carried out on a wide range of soils but optimum

are well drained, loose, fertile and sandy alluvial soils that have a pH value

between 5.4 and 6.75. Very low pH values have a drastic effect on growth,

whereas some varieties can tolerate a pH value up to 8 (Naturland, 2002). Good

drainage is crucial, as sesame is very susceptible to short periods of water logging.

Sesame is intolerant of very acidic or saline soils (Bennet, 2011). The total amount

of water required to grow sesame crop ranges from 600 to 1000 mm, depending on

the cultivar and the climatic conditions (Hansen, 2011). Good harvests can be

expected when rainfall of 300-600 mm is optimally spread throughout the

vegetation period. During each of its development stages, the plant is highly

susceptible to water-logging, and can therefore only thrive during moderate

rainfall, or when irrigation is carefully controlled in drier regions (Naturland,

2002). The water requirement can be met from available soil moisture at sowing,

rainfall during the growing season and irrigation (Hansen, 2011). This is because

due to its tap roots, the plant is highly resistant to drought, and can provide good

harvests even when only stored soil water is available. When irrigated, or during

summer rain spells, sesame grows better in sandy than in heavy soils. This is due to
its sensitivity to high soil moisture contents (Naturland, 2002). Sesame needs long

periods of sunshine, and is generally a short-day plant – whereby varieties exist

which are unaffected by the length of the day (Naturland, 2002). Sesame needs a

constant high temperature, the optimum range or growth, blossoms and fruit

ripeness is 26-30°C. The minimum temperature for germination is around 12°C,

yet even temperatures below 18°C can have a negative effect during germination

(Naturland, 2002). Pollination and the formation of capsules is inhibited during

heat-wave periods above 40°C. In regions visited by strong, hot winds, the plants

only form smaller seeds with lower oil content. Sesame is sensitive to strong winds

when the main stem is fully grown. Tall varieties should not be planted in regions

which have strong winds during the harvesting season (and, if necessary, hedges to

protect against the wind should be planted) (Naturland, 2002). The response of

sesame to both temperature and daylength indicates that it should be cultivated in

the wet season in the tropics or in the summer in the warmer temperate areas.

While there is some variation between cultivars, the base temperature for

germination is about 16oC (Bennet, 2011). This warm-season annual crop is

primarily adapted to areas with long growing seasons and well-drained soils

(Hansen, 2011).

Sesame is an annual plant, which grows either bush-like or upright, depending on

variety. The plant is usually 60 to 120cm and bears plenty of pink-white color fox-
glove type flowers. The pod or fruit which is a dehiscent capsule held close to the

stem, appears soon containing white, brown or black seeds depending up on the

cultivar type, arranged in rows inside. Each pod (2-5 cm in length) is a long

rectangular box like capsule with deep grooves on its sides and may contain up to

100 or more seeds (www.nutrition-and-you). When ripe, the capsule shatters to

release a number of small seeds. The seeds are protected by a fibrous ‘hull’ or skin,

which may be whitish to brown or black depending on the variety. 1000 seeds

weigh some 4-8g (Chemonics, 2002).

2.5 Harvesting and post harvesting handling of sesame seed

Sesame seed is harvested when about 50% of capsules turn yellow in colour from

green. Other indications of the optimum time for harvesting (physiological

ripeness) include; lowest capsules turning brown and beginning to pop open, stem

turning yellow, leaves beginning to fall off, end of blossoming, leaves turning

yellow (Kimbonguila et al., 2009). Harvesting should not be delayed in order to

prevent seed loss through shattering. The size and shape of sesame seed (ie small

and flat) makes it difficult to move much air through it in a storage bin. Therefore,

the seeds need to be harvested as dry as possible and stored at 6 percent moisture

or less (Langham et al., 2008). If the seed is too moist, it can quickly heat up and

become rancid. High levels of humidity can cause sesame to take on moisture

again and go mouldy; it should therefore only be stored for a short while, or in air-
tight containers. If the critical 6% cannot be reached by using only sun drying then

artificial methods must be employed. This is because sesame above 5.1% starts

getting docked for moisture weight, and above 6.9% moisture, there are quality

discounts. Sesame is generally harvested manually by cutting stems with sticks,

and then left to dry for the first 2-3 days after cutting in a windrow (Naturland,

2002). The leaves dry out quickly there, making it easier to bundle them into

sheaves. Plants are tied with a rope into small bundles or sheaves (diameter of 15

cm, bottom: 45-80 cm) and positioned erect on a mat or tarpaulin for drying to

complete. This prevents seed wastage ns contamination. The sheaves should be

positioned so that the sun can shine down directly onto the capsules. This results in

less drying time, better heat and air circulation, avoidance of fungi infection, ease

of turning when shaking bundles, more extensive shaking/threshing with fewer

losses. The sheaves should not need to be dried for longer than 15 days. After the

sheaves have dried out fully, they are tipped out onto sturdy cloths or canvases and

threshed with sticks. The cloths/canvases should be at least 6 m², to avoid

contamination with stones and soil. Mechanical harvest is better, as the unripe

plants are cut, and then the pre-dried sheaves threshed out. This reduces the

amount of seeds lost, and the hay makes better fodder. Most threshing machines

with a sheaf pick-up function are suited to the task. Varieties that open are easier to

thresh mechanically than those that remain closed, as less force is needed. . Sesame
seed is easily threshed and relatively delicate, so drum speed should be reduced to

about half of that required for cereals, and the concave clearance made as wide as

possible. Seed damage during harvesting affects both the viability of the seed,

storage and the quality of the oil. After the seeds have been harvested and dried,

the storage sacks must be checked and free of insects. Packaged sesame should be

stored in a dark place at low temperatures (below 18°C) and low relative humidity.

Also sesame contain more of unsaturated fats hence should be stored in air-tight

containers to avoid them turning rancid. Under optimum storage conditions,

sesame can be stored for several months even up to 1 year. For safe longterm

storage, sesame seed should be clean, have moisture content no more than 6% and

be stored at a relative humidity of approximately 50% and at a temperature less

than 18°C (Bennet, 2011).

2.6 Nutritional benefits of sesame seed

Sesame seed (Sesamum indicum L.) is an oilseed with a chemical composition of

about 50-52% oil, 17-19% protein and 16-18% carbohydrate (Tunde-Akintunde

and Akintunde, 2004). Its seed contains about 42-54 % quality oil, 22-25 %

protein, 20-25 % carbohydrates and 4-6% ash. The hull contains large quantities of

oxalic acid, crude fiber, calcium and other minerals. When the seed is properly

dehulled, the oxalic acid content is reduced from about 3 % to less than 0.25 % of

the seed weight (Akinoso et al., 2010). Sesame seed contains antioxidants which
inhibit the development of rancidity in the oil. In the food industry, where synthetic

antioxidants are used extensively, there is an increasing demand for more of these

natural products (Bennet, 2011). The nutritional benefits derived from sesame

seeds are based on the variety being utilized. Sesame seed (Sesamum indicum L.),

from Northern Congo were reported to contain 5.7% moisture, 48.5% crude oil,

20% crude proteins, 7.78% carbohydrate (by difference), 9.4% crude fiber and

4.2% ash (Nzikou et al., 2010). The protein content of White Sudan sesame seed

was high (~25%) similar to other foodstuffs rich in proteins such as almond,

hazelnut protein the contents of which were respectively, 20% and 21% (Borchani

et al., 2010). The ash content in raw sesame was relatively high (~5%) compared

to other products of great consumption such as almond (3%), and the pistachio

(2.7%) (Borchani et al., 2010). Other Sudanese local and improved varieties

considered by El Khier et al (2008) had protein content of 32.50 to 35.94 and

33.43 to 40.00 respectively. The seeds also contained significant amount of

important minerals with the Potassium concentration being the highest, followed

by Phosphorus, Magnesium, Calcium and Sodium (Loumouamou et al., 2010). For

White sesame seed (S. indicum L.) from Sudan, oil was 52.24%, protein 25.97%,

fibre 19.33% and ash 4.685 (El Khier et al, 2008). The predominant mineral

composition was calcium followed by potassium, magnesium and phosphorus. All

other elements were present in comparatively low concentrations (Elleuch et al.,

2007). This is similar to the results obtained by Borchani et al. (2010) for white

Sudanese sesame. Potassium is an essential nutrient and has an important role is

the synthesis of amino acids and proteins. Calcium and Magnesium plays a

significant role in photosynthesis, carbohydrate metabolism, nucleic acids and

binding agents of cell walls. Calcium assists in teeth development Magnesium is

essential mineral for enzyme activity, like calcium and chloride; magnesium also

plays a role in regulating the acid-alkaline balance in the body. Phosphorus is

needed for bone growth, kidney function and cell growth. It also plays a role in

maintaining the body’s acid-alkaline balance. The presence of these minerals also

confirms the fat that sesame seed is of high nutritional benefit to its consumers

2.7 Utilization of sesame seed

Sesame is commercialized in a number of forms. Most sesame is processed directly

into oil by the grower or within the producing region, but can also be sold in

various stages of processing, for various uses, such as meal, paste, confections, and

bakery products. Sesame seeds can also be consumed directly as a highly nutritious

foodstuff (Naturland, 2002). Sesame seeds have delicate nutty flavor. Their flavor

indeed becomes more pronounced once they are gently roasted under low flame

just for few minutes. De-hulled sesame seed is mainly used to add texture, taste

and aesthetic value to a variety of bakery products like bread, bread sticks, cookies,

sesame bars etc; and also as an additive to cereal mixes and crackers. It is also used
in the making of tahin or sesame butter - a paste of ground sesame seeds, which is

used as an ingredient (in Greece) and halva, placed within breads or sprinkled on

the surface of bread and breadsticks as a garnish (Germany and the Netherlands)

and for the preparation of rolls, crackers, cakes and pastry products in commercial

bakeries (Nzikou et al., 2009). Ground and processed seeds can also be used in

sweet confections, candies are made from sesame mixed with honey or syrup and

roasted (in South Asia, middle East and East Asia) while sesame paste and starch

are used to make goma-dofu (Japan). Sesame seed can also be in the manufacture

of margarine, sprinkled over salads and desserts, particularly sundaes and other ice

cream based preparations, preparation of gomshino (a Japanese delicacy) and

soybean oil. It can also be used in other food dishes including Mexican and East

Asian cuisines. Sesame seed is primarily grown for its oil in Nigeria and the oil is a

primary source of cooking oil in Eastern Nigeria. The major portion of sesame

seed produced in countries like Nigeria and India is used for extraction of oil.

Sesame oil is mostly used as traditional cooking oil in Chinese food items and in

Japan. Sesame seed is an excellent source of high quality oil and protein, its oil is

odourless and close in quality to olive oil (Tunde-Akintunde and Akintunde, 2007).

Sesame oil has no odour, it is straw-like in colour and has an excellent taste.

Sesame seed oil is a natural salad oil, requiring little or no winterization, is one of

the few vegetable oils that can be used directly without refining and is used widely
as cooking oil. Because of the excellent quality of the edible oil it produces,

sesame is often called queen of the oil seed crops. Light sesame oil have a high

smoke point and is suitable for deep-frying, while dark sesame oil (from roasted

sesame seeds) has a slightly lower smoke point and is unsuitable for deepfrying.

Instead it can be used for the stir frying of meats or vegetables, or for the making

of an omelette. East Asian cuisines often use roasted sesame oil for seasoning. It is

also used widely for production of magarine, shortening, canned sardine and beef

as well as in soap and confectionary industries (NAERLS, 2010). Sesame oil has a

high preservative effect though the seeds are prone to rancidity because of its high

oil content. The oil prevents rancidity due to a preservative within the oil called

sesamol. Sesame oil obtained during the first, cold pressing is one of the costliest

produced. The oil is light yellow, does not dry out, and can be used with strong

heat. Sesame oil obtained from the second, warm pressing and extraction has a

lower quality than cold-pressed. In the industry, sesame oil may be used as a

solvent in injected drugs or intravenous drip solutions, a cosmetics carrier oil, to

coat stored grains to prevent weevil attacks. The oil also has synergy with some

insecticides. Lower grade sesame oil can be used locally in soaps, lubricants, and

illuminants. Sesame oil can also be used as a raw material in the manufacture of

inks (sesame oil yields a top quality ink after it is burnt), paints, and

pharmaceuticals (as healing oil or a vehicle for drug delivery). The oil also has
additional use in the industrial preparation of perfumery, cosmetics (skin

conditioning agents and moisturizers, hair preparations, bath oils, hand products

and make-up), insecticides and paints and varnishes. However, all of these uses are

comparatively insignificant in terms of the quantities used. The seed is typically

crushed intact for the oil. This, however, yields a meal that is made bitter and

somewhat indigestible by the presence of the fibrous husk. As such the meal is

only useful as cattle feed. The quality of the meal can however be improved by

removing the seed coat, dehulling, before crushing. In India, where sesame meal is

an important food, this process is a standard feature of an oil extraction plant. The

meal remaining after oil extraction has unique nutritional properties. It has a high

protein concentration which is rich in methionine, cysteine and tryptophan. Since

these amino acids are missing from a number of other sources of vegetable protein,

such as soya, sesame meal or flour can be added to recipes to give a better

nutritional balance to health food products thus complementing most oil seeds and

vegetable proteins very well. The seed cake is also an excellent protein supplement

in the animal feed industry. The press cake can also be used for food enrichment of

infant weaning foods (NAERLS, 2010). Different cultures have different

traditional uses for sesame. In Nigeria, industrial processing and utilization of

sesame have not been fully developed. However, the product is locally processed

and utilized in various forms in the states where the crop is cultivated. Principal
among the products are: “Kantun Ridi” and “Kunun Ridi”. At the local level, oil is

also extracted from the seed and the cake is made into “Kulikuli” which together

with the leaves are used to prepare local soup known as “Miyar Taushe”. The oil is

used locally for cooking as well as for medicinal purposes such as the treatment of

ulcers and burns. The stem and the oil extract are equally used in making local

soap. In all the states where sesame is cultivated, women are more involved in the

local processing of sesame seed into commercial products. In Japan, tan and black

sesame seed varieties are roasted and used for making the flavoring gomashio. In

Greece the seeds are used in cakes, and in Togo they are a main soup ingredient.

The seeds are also eaten on bread in Sicily and France (called "ficelle sésame",

sesame thread). In Congo and Northern Angola, ground sesame or wangila is a

delicious dish, especially when cooked with smoked fish or lobsters. In Manipur

(North Eastern State of India), black sesame is used in the preparation of a favorite

side dish called 'Thoiding' and in 'Singju' (a kind of salad). Also in Tamil Nadu,

India, a ground powder, Milagai Podi, made of sesame and dry chili is used to

enhance flavor and consumed along with other traditional foods

2.8 Adverse effects

Though sesame seeds have a wide range of health and commercial benefits, they

have some anti-nutritional properties. Sesame seeds contain a high amount of the

phytic acid which is an anti-nutrient. Another disadvantage of the seed is that it

produces allergic reactions in some people. The allergy may be mild and appear as

hives, dermatitis and itching or be severe and lead to severe physical symptoms

like vomiting, pain abdomen, swelling of lips and throat leading to breathing

difficulty, chest congestion and death. The laxative effect of sesame also indicates

that sesame oil should not be used by people who have diarrhea.

2.9 Gas chromatography–mass spectrometry (GC-MS)

Gas chromatography–mass spectrometry (GC-MS) is an analytical method that

combines the features of gas-chromatography and mass spectrometry to identify

different substances within a test sample. Applications of GC-MS include drug

detection, fire investigation, environmental analysis, explosives investigation, and

identification of unknown samples, including that of material samples obtained

from planet Mars during probe missions as early as the 1970s. GC-MS can also be

used in airport security to detect substances in luggage or on human beings.

Additionally, it can identify trace elements in materials that were previously

thought to have disintegrated beyond identification. Like liquid chromatography–

mass spectrometry, it allows analysis and detection even of tiny amounts of a

substance (Hoffmann & Vincent, 2013).

GC-MS has been regarded as a "gold standard" for forensic substance

identification because it is used to perform a 100% specific test, which positively

identifies the presence of a particular substance. A nonspecific test merely

indicates that any of several in a category of substances is present. Although a

nonspecific test could statistically suggest the identity of the substance, this could

lead to false positive identification. However, the high temperatures (300°C) used

in the GC-MS injection port (and oven) can result in thermal degradation of

injected molecules, thus resulting in the measurement of degradation products

instead of the actual molecule(s) of interest (Hoffmann & Vincent, 2013).

Fig 2.2: Schematic of GC-MS (Hoffmann & Vincent, 2013)

2.10 Mass Spectrometry

Mass spectrometry (MS) is an analytical technique that produces spectra (singular

spectrum) of the masses of the atoms or molecules comprising a sample of

material. The spectra are used to determine the elemental or isotopic signature of a

sample, the masses of particles and of molecules, and to elucidate the chemical

structures of molecules, such as peptides and other chemical compounds. Mass

spectrometry works by ionizing chemical compounds to generate charged

molecules or molecule fragments and measuring their mass-to-charge ratios

(Hoffmann & Vincent, 2013). In a typical MS procedure, a sample, which may be

solid, liquid, or gas, is ionized by bombarding it with electrons. This may cause

some of the sample’s molecules to break in to charged fragments. These ions are

then separated according to their mass-to-change ratio, typically by accelerating

them and subjecting them to an electric or magnetic field: ions of the same mass-

to-charge ratio will undergo the same amount of deflection (Sparkman, 2006). The

ions are detected by a mechanism capable of detecting charged particles, such as

an electron multiplier. Results are displayed as spectra of the relative abundance of

detected ions as a function of the mass-to-charge ratio. The atoms or molecules in

the sample can be identified by correlating known masses to the identified masses

or through a characteristic fragmentation pattern (Hoffmann & Vincent, 2013).