An Extract from The Floral One

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Do you know sunflower? That big yellow flower with brown in the middle and has a high stem to stand. Accidentally, this morning while I was walking along one of the aisles of a supermarket near my house, I found a bottle of bright yellow oil, and it was said as sunflower oil. Hmmm, what a novel thing for me. Then, I decided to write about sunflower oil. 

Sunflowers (Helianthus annuus) are a large plant, yet have a relative short growing season. Each flower has single stalk to stand with the flower on top. During the growing season, the individual flowers are each pollinated. It takes 30 days after the last flower is pollinated for the plant to mature. A single sunflower plant may have 1.52 - 2.1 m of tall and 7.62 - 15.24 cm of diameter. Sunflowers will grow well within a temperature range of 20 - 25 C. Whether the sunflowers grow upper 25 C or drought during its growing time, the oil yield will reduce.\

There're several countries that produce sunflower as their agriculture product : 

Sunflower oils come from its seed extracts. 

Sunflower seeds are four-sided and flat, generally 0.6cm long and 0.3cm wide. Its hull contains 20% protein and 30% lipids. Sunflowers are used to make oil, meal, and confectionary products. For every 100kg of sunflower seeds may produce 40kg of oil, 35 kg of high-protein meal. 

To make an oil from sunflower seeds, here are the steps :

1. Cleaning and Grinding → the incoming seeds have to pass a metal detector to remove any trace of harmful metals before being de-hulled. Then, the seeds are going to de-hulling process to remove the hull. De-hulled seeds then crushed into the proper concistency and heated as to extract the oil content of it. Yet, some impurities may follow the oil released.

2. Pressing → The heated meal (crushed de-hulled seeds) then go to the screw press. During the meal is going through the screw press, the pressing is progressively increasing from 68.95 to 206.85 kPa as the oil is squeezed out.

3. Solvent Extracting → At the end of screw press, the meal cake remaining is processed by solvent extraction to achieve the maximum yield. The solvent commonly used is hexane is to dissolve the remaining oil in the cake.

4. Removing Solvent → About 90% of solvent then evaporates, but still leaving the last 10%. The remaining solvent is steamed with the oil, and the solvent may evaporate first. Evaporated solvent is used again for the next solvent extraction.

5. Refining → The oil is heated between 40 to 85 C and mixed with alkaline substances. Oils are also degummed by heated with steam between 85 to 95 C, the gums will pecipitate out and be removed by centrifuge. Next, the oils are bleached by filtering it through an activated carbon that adsorb certain pigmented material from the oil. Finally, the oils are deodorized by steaming in a vacuum at between 225 to 250 C.

Sunflower oil contains linoleic acid (48-74%), oleic acid (14-40%), palmitic acid (4-9%), and stearic acid (1-7%). The conventional sunflower oil is used for home cooking oil, margarine, industrial use (paint), cosmetics (high-oleic type).

Sunflower oils contain lechitin, tocopherols, carotenoids, and waxes. It's light in taste and appearance, and has a high vitamin E content. Its characteristics in room temperature are : 

a) Smoke point (refined) : 232 C

b) Smoke point (unrefined) : 227 C

c) Density (25 C) : 917 kg/m3

d) Refractive index (25 C) : 1.473

e) Viscosity (25 C) : 0.04914 kg/(M.S)

Several benefits wheter consuming sunflower oil :

1. Diet and Cardiovascular benefits : high in polyunsaturated fatty acid, low levels of trans fat, clean taste.

2. Restaurant and Indsutry Uses : can be done during high cooking temperatures, maintain foods' freshness, good for snack foods manufactures.

3. Skin Protection : retain moisture in the skin, resist infection in pre-term infants.

On the other hand, sunflower oil has a negative impacts when consumed at too high portion. Its omega-6 polyunsaturated fatty acids may lead to breast cancer and prostate cancer.

Reference : 

Anonim. 2010. Sunflower Crude and Refined Oils. Rome : Food and Agriculture Organization.