Coffee lipid storage

The lipids of coffee play an important part in the store-ability of roasted coffee. During storage the lipids can be oxidized if oxigen is present and it changes the aroma of coffee, too. 

The aims of our investigation were to separete the most important classes of coffee lipids and to analyse their change during processing (roasting, storage and making coffee). 

As summarized in the review by Clifford (1985b), the terms crude and total lipid refer to substances extracted by a non-polar solvent and may include non-lipid substances such as caffeine. The yield is a function of the extraction method as much as of the composition of the beans. The crude lipid includes the wax coating the coffee bean (0,2-0.3 %), the main constituents of which are the C2o and C22 amides of 5-hydroxytryptamine [l//-indol-5-ol, 3-(2-aminoethyl-), serotonine]. These amides have their importance. As they are possible antioxidants, it has been suggested that premature dewaxing leads to a fall in the bean quality during storage. The major part of the crude lipid is a typical seed oil, with triglycerides of fatty acids, some other esters and unsaponifiable matter. 

Because many foods are emulsified materials (e.g., milk, mayonnaise, coffee creamers, salad dressings, butter, and baby foods), an understanding of the mechanisms of lipid oxidation in emulsions is crucial for the formulation, production, and storage of food products. Oil-in-water emulsions consist of three different components water (the continuous phase), oil (the dispersed phase), and surface-active agent (the interface). 

There is significant difference between the two species in the quantity of lipids can be extracted. The effect of roasting and storage on the lipid content, and the lipid quantity may be extracted from the coffee drink showed in the Table 2. Effect of roasting, storage and making coffee on the lipid quantity. 

The roast increases the extractable lipid and at the end of storage decreases again. The coffee drink have 10% of original roasted beans. 

The unsaturated triglycerides change during the storage and change the saturated/unsaturated fatty acid proportion, too. The coffee drink has 10-15% of total lipid and the quantity of sterol fraction higher. 

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