Sesame Oil

Introduction

Sesame oil has a range of uses in the kitchen, and is an integral part of many dishes around the globe. Smoky and nutty in flavour, sesame oil is one of the most popular seed oils in the world. Its culinary reputation is preceded by its rich cultural status across Asia and beyond. In this article, we’ll take a detailed, scientific look at the journey from sesame seed to a diner’s plate, where we’ll look at the plant’s botanical makeup, its production methods, and the culinary science of sesame oil.

Sesame Seeds

The Sesame plant (Sesamum indicum) is an annual flowering plant that belongs to the Pedaliacae family. It grows best in the tropics and sub-tropics, particularly in India, China, and tropical Africa. The edible parts of the plant are the slender seeds, which are protected inside the capsule known as a ‘fruit’.

The oil-rich seeds range in colour from reddish-brown, to charcoal-black when fully ripe. These are the seeds we use to grow and produce sesame oil — either by cold-pressing, or by employing more technical extraction processes.

Production

Cold-Pressing

The most popular method of cold-pressing sesame oil is to use a traditional millstone with a base of coco seed cake and a back pressure of 5-6 atmospheres. The traditional approach maintains the fragrance and flavour of sesame oil, as well as its health benefits, but produces only a small amount of oil and is time consuming.

This method is usually used for domestic sesame oil production as it’s time-consuming and labour-intensive. The raw sesame is heated to between 110-120°C before being fed into the millstone. This helps to promote oil flow and reduce friction during the extraction process.

Modern Production

The oil-rich sesame seeds are cleaned and separated from dust or foreign particles before being processed. Next, the seed is cracked, hulled and coarsely ground.

The resulting product is then separated using a dry sieving and pulverized product washed with a solvent liquid. This helps to remove the germs and spores. After drying and de-hulling, the seeds are ready for oil extraction.

Modern production processes use either a solvent-based or a hydraulic press to extract the oil. In solvent extraction, the seeds are dried and soaked in lye or caustic soda before being pressed. This helps to remove most of the oil content and the remaining residue is filtered through nitrogen.

In the hydraulic press method, the raw seeds are fed into a screw press that squeezes out the oil. This process is carried out at cold temperatures, as heat can damage the oil and its flavour. The oil that is collected is treated with a decolourant to reduce the colour and acidity of the oil. This results in a clearer and lighter coloured oil, which is a key characteristic of sesame oil.

Health Benefits

Given its botanical make-up, sesame oil is highly nutritious, providing essential fatty acids and vitamins that improve the health of skin, hair, and most importantly the heart. It contains polyunsaturated (omega-9) and monounsaturated (omega-6) fatty acids, including oleic acid and linoleic acid. It is also rich in antioxidants like polyphenols, which help to fight free radicals in the body and reduce the risk of diseases like cancer.

The presence of vitamin E in sesame oil helps to protect the skin from damage. It is also rich in copper, calcium, magnesium, and iron. Copper promotes the formation of collagen, which helps to keep skin healthy and prevent aging. While calcium and magnesium work together to maintain strong bones and teeth.

Sesame Oil in the Kitchen

Sesame oil has a host of uses in the kitchen. As a cooking oil, it has a high smoke point, making it an ideal choice for stir-frying. It adds a rich and nutty flavour to food, imbuing it with a distinct sesame aroma.

It has a multitude of applications in salads, dressings, dips, and marinades. These might include hummus and pesto dishes as well as traditional Asian dishes such as soy-miso dressings.

Apart from its versatile culinary uses, sesame oil is also used as a flavouring agent in a range of desserts such as ice cream, puddings and cakes.

Conclusion

Sesame oil has a long and rich history in many diverse cultures, where it is valued for its flavour, medicinal and health benefits. As a cooking ingredient, too, it is unrivalled. With its versatility and range of uses, sesame oil holds a special place in the kitchen and is sure to remain a staple for years to come.

The journey from sesame seed to dinner plate is scientifically advanced and technologically driven. From harvesting and cleaning, to oil extraction and treatment, every step of the process is carefully managed to ensure quality and taste. From its ancient roots to its current prominence, sesame oil continues to be a favourite of chefs and diners alike.