FOOD. Science. Technology. Quality

Food. SCIENCE. Technology. Quality

Food. Science. TECHNOLOGY. Quality

Food. Science. Technology. QUALITY

Authors

AGNIESZKA OBIEDZIŃSKA, BOŻENA WASZKIEWICZ-ROBAK

Title

Cold pressed oils as functional food

Abstract

During the increased demand for „natural” food in the group of vegetable fats, consumers search for products other than those produced by extracting oils from seeds with the use of organic solvents or those undergoing subsequent chemical and physical refining processes. Cold pressed oils are such products, and when eaten, they can prevent or retard the development of diet related lifestyle diseases such as obesity, coronary heart disease, and hypertension. Among the cold pressed oils, there are oils obtained from seeds (flax, camelina, evening primrose, borage, amaranthus, pumpkin, black currant), fruits (olives, sea buckthorn), nuts (hazelnuts, walnuts), or germs (wheat kernel). First of all, they are a rich source of unsaturated fatty acids, including essential fatty acids: linoleic and alpha-linolenic. Also, they provide bioactive compounds such as tocopherols and tocotrienols, free and esterified sterols, hydrocarbons (squalene), triterpenic alcohols, carotenoids, chlorophylls, and other compounds responsible for the colour, which are very valuable for human nutrition. The content level of those compounds in cold pressed oils mainly depends on the quality, the type, and the variety of raw substances. The additives applied did not inhibit the production of primary lipid oxidation products (peroxides and hydroperoxides), and the thyme extract demonstrated a strong oxidation–supporting activity. An antioxidant activity of all the additives was observed with regard to the secondary lipid oxidation products denoted as TBARS. None of the additives showed any protective activity are regards the egzogenitc amino acids. The highest loss of the available lysine was found in a sample with rosemary extract added; it amounted to nearly 51 %. The highest decrease in the content of available methionine, amounting to about 41 %, was reported in the samples with the thyme extract applied. The protective activity of anti-oxidants was found as regards the thiamine. In the samples with BHT and rosemary additives, significantly lower losses of this vitamin were found compared to the control sample.

Keywords

cold pressed oils, bioactive compounds, fatty acids, sterols, tocopherols, squalene

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