Week 9 Flashcards
Lipid refining
Lipid refining is the process of taking a raw lipid, removing the problematic parts, and ensuring that it will perform the best way possible in food manufacturing and production. This includes; refining, degumming, neutralizing, bleaching, deodorizing, and winterizing among some others.
Rendering
Rendering is only done with animal fats. It is where the fats/lipids are isolated from the meat and protein of the animal. This can be done through a wet or dry process but usually just includes heating the meat up and collecting the melted fat for further refining.
Degumming
Degumming is where water is added to the oil to take out the phospholipids which can increase the viscosity of an oil and cause it to oxidize. The layers then separate and the water with the phophotides are separated out. Degumming is removing phospholipids
Neutralizing
Neutralizing happens when caustic soda is added to the oil and the soda reacts with free fatty acids to form soaps that can then be strained off. So, neutralization is getting rid of free fatty acids.
Bleaching
A bleaching agent is then added to the oil which helps to illuminate chlorophyll compounds and other compounds that contribute to color. Trace metals, residual soaps, and residual phospholipids are also removed in this step. Bleaching gets rid of chlorophyll and other color pigments
Deoderizing
Deodorizing takes place when short chain, volatile compounds are removed through the use of steam. These compounds contribute to off flavors and aromas, mostly consisting of aldehydes and ketones.
Blending
Oils are blended to achieve certain behavioral characteristics. For example, if you want an oil that has a lower smoke point to have a higher one, you could blend in an oil with a higher smoke point to counteract the lower one. Also you can add different oils to increase hydrogenation ratios and create different flavor profiles.
Fractionation
Fractioning is essentially the same as winterization. This is where and oil in cooled to a point where some of the oil begins to crystalize. These are the longer chain fatty acids or the ones that would separate out first if the oil was stored in a cool place. These crystals are then separated out and the remaining liquid oil is more stable at colder temperatures.
Hydrogenation
Hydrogenation is the process of injecting hydrogen gas into an oil solution and the hydrogen then is able to go in and protonate some of the carbons participating in double bonds. Nickel is a catalyst used because hydrogen loves to bind to it and so do fatty acids, but whatever the element used there needs to be a catalyst and heat
Partial Hydrogenation
Partial hydrogenation happens when not all of the double bonds are hydrogenated. This could either come from not enough hydrogen is added or not enough catalyst, or it can come from the fact that during the process of hydrogenation, the reactions can be reversible. The reacted hydrogen can pop off again. There are a few ways that a fatty acid could go when in the hydrogenation process. If can gain two more hydrogens and become completely saturated, it can reverse and go back to an unsaturated cis bond, or the hydrogens on the fatty acid could flip flop and a trans bond could be formed.
Full hydrogenation
full hydrogenation happens when two hydrogens are fully added to two previously double bonded carbons, making the fatty acid fully saturated in hydrogens
Interesterification
Interesterification can be described as a redistribution of different fatty acids on a triglyceride on the glycerol backbone. These fatty acids can be randomized to help slow crystal morphing within the bulk lipid and/or can produce more desirable traits. The fatty acid on position 2 is the one that is most likely to get absorbed in the body and so if you place the fatty acid that you want the most there, that would be beneficial and more likely to be absorbed. The melting point, nutritional value, and functional value is altered though this process.
This process happens first by using a catalyst. The fatty acids can be arranged in a random or arranged order. Next the fatty acid of choice is hydrolyzed from the glycerol backbone and attached to an enzyme while the other fatty acid does the same thing and they are able to switch.
Crystal structure
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Mouthfeel
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Grittiness
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Spreadability
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