Sesame Seeds - An overview of the applications, manufacturing & global industry

Sesame seeds comprise a crazy taste and a fragile, about imperceptible, chew to many Asian plates. They are as well the major ingredients in sesame seed paste and the magnificent Middle Eastern sweet call halvah. Sesame seeds can be available all through the year. Sesame seeds are an excellent resource of Best source of copper, Resource of manganese, it is also rich in magnesium, calcium, phosphorus, iron, zinc, molybdenum, as well selenium. India produces a wide range of sesame varieties with different grades each peculiar to the region. Sesame is harvested twice a year and is available around the year.

Product & Its Application
Sesame has been classified in different colours as White seed Yellow seed Red seed Brown seed Black seed.

Uses of sesame in various forms:

Sesame seeds are used in various food and snack preparations as well as in, salad dressing. Sesame is used mainly as a food ingredient in whole, broken, crushed, shelled, powdered and paste forms.
a.) Oil: Sesame seeds contain the highest oil compared to any other oilseed to an extent

of 50% and above. The unique qualities of sesame oil are stability and resistance to rancidity, with long shelf life due to the presence of the high level of natural antioxidants. Other than for cooking and salad dressing, the oil is an essential ingredient in the manufacture of soaps, pharmaceuticals (as healing oil) and lubricants with additional use in cosmetic and skin care industries.
b.) Meal: Sesame seeds are rich in protein with about 25% of their weight. Sesame meal contains 35 - 50% protein and used as feed for poultry and livestock.

Sesame seed cleaning and sorting Sesame seed soaking in water tanks Sesame seed dry roasting Roasted sesame seed Crushing in expellers Filtration of roasted sesame oil Packing of oil in tins/bottles Packing in cartons for export Sesame seed aqua de-hulling Separation of hulls by centrifuging Drying of de-hulled sesame seed Packing in multi-wall laminated paper bags

Industry Overview:

Sesame is cultivated over an area of about 74 lakh hectares in the world with an annual production of about 40 lakh tonnes and yield of 535 kg/hectares. Myanmar and India are the major sesame growing countries, accounting for almost 40% of the global sesame production. India accounts for over one-fourth of land area under sesame cultivation in the world. Among oilseeds, sesame occupies 2nd position after groundnut as far as exports of oilseeds are concerned.

More than 40% of the sesame seeds produced in India is exported every year. India is the largest exporter of sesame seeds in the world, contributing nearly 25% to international trade. Vietnam is the primary destination for Indian sesame seed, followed by South Korea, USA, Taiwan and China. More than 85% production of Sesame comes from West Bengal, Madhya Pradesh, Rajasthan, Uttar Pradesh, Gujarat and Andhra Pradesh.

Manufacturing Process:
Sesame seeds have a thin shell or husk which needs to be removed and this process is known as de-hulling. The weight of hull is about 17% of total weight of sesame seed. The hull contains a great deal of oxalic acid and in-digestive fibre. Oxalic acid can reduce biological utilization ratio of Ca in Food and influence taste. After de-hulling, oxalic acid can reduce from 3% to 0.25% in sesame seeds, which improve the protein digestibility greatly. So, de-hulling of sesame seeds is the precondition of enlarging application of sesame in the food field. Hulled sesame seeds are softer and tastier than un-hulled seeds. Sesame seeds are also an excellent source of unsaturated fatty acids and phytosterols.

Wet De-hulling Process and dry de-hulling process
The dry de-hulling process is that dry the sesame seeds after cleaning at a certain level, which can dehydrate the moisture in hull quickly and be brittle. Then use clash de-hulling method, the hulls are peeled from sesame seeds. The dry process is short in technology line, few investments in equipment but low at a de-hulling rate, easily get yellow or brown even burnt at high temperature. So, for commodity use, the dry method is not commonly used in processing sesame seeds, generally, only for little quantity self-use in some foodstuff factories.

A wet de-hulling process has been developed for easy removal of the husk from the sesame seed. The process of de-hulling consists of preliminary cleaning and grinding, hot lye treatment, removal of the skin and pigments, thorough washing and drying. The de-hulled seed is expelled to get high-grade oil. The cake is further expelled to recover the residual oil and protein-rich meal. The protein-rich sesame cake flour finds multiple uses in protein fornication of food preparations. The de-hulled sesame seeds and flour offer good potential for both domestic and export markets. A process has also been developed for washing of white sesame seeds to produce confectionery grade product. Brilliant white seeds are produced, which is known as hulled sesame seeds.

Process Flow of Complete Sesame Hulling Plant

Soaking: The purpose of soaking is that make hull of sesame seeds sopped up water to expand for peeling off from seeds. The project use lye, soaking raw sesame seeds in a certain temperature, which improve the speed of infiltration ratio of water into the hull, shorten the soaking time greatly to 30-40 minutes from original 7-8 hours. The produce periods is shortened. At the same time, lye weakens pigments in the hull for the whiteness of sesame seeds.

De-hulling: The project use vertical huller to make sesame seeds in relative movement. By soft friction between sesame seeds, the hull is removed.

Separating: It is the key process in sesame seeds production, affecting the final yield of the finished product. Generally, put the mixture of hulls and seeds into the water tank, by the different buoyancy of hulls and seeds, fish out the hulls by hand. But it is not the thorough method by buoyancy. So, the project uses separation theory by different geometrical sizes of hulls and seeds. Namely, use best soaking technology to soften hulls, increase crush rate of hulls but do not influence the intact rate of seeds when hulling, then use hulls smaller than seeds, taking away the hulls with water flow in the subsidence-type automatic separator. The seeds are captured. The separation of hulls and seeds succeeded. The technology saves labour and product yield next to the theoretical value.

Drying: The process uses a single chamber fluid bed drier. The sesame seeds float in hot air flow and polish by friction between seeds, which decrease sticky hull rate and improve the smoothness of finished product. It avoids the disadvantage of yellow, unpolished, high sticky hull rate etc. in normal fluid bed drier.