Effect of Refining and Fractionation Processes on Minor Components, Fatty Acids, Antioxidant and Antimicrobial Activities of Shea Butter.

Shea butter is becoming increasingly popular in foods, cosmetics and pharmaceutical products. This work aims to study the effect of the refining process on the quality and stability of fractionated and mixed shea butters. Crude shea butter, refined shea stearin, olein and their mixture (1:1 w/w) were analyzed for fatty acids, triacylglycerol composition, peroxide value (PV), free fatty acids (FFA), phenolic (TPC), flavonoid (TFC), unsaponifiable matter (USM), tocopherol and phytosterol content. Additionally, the oxidative stability, radical scavenging activity (RSA), antibacterial and antifungal activities were evaluated. The two main fatty acids in the shea butter samples were stearic and oleic. The refined shea stearin showed lower PV, FFA, USM, TPC, TFC, RSA, tocopherol and sterol content than crude shea butter. A higher EC50 was observed, but antibacterial activity was much lower. The refined olein fraction was characterized by lower PV, FFA and TFC in comparison with crude shea butter, but USM, TPC, RSA, EC50, tocopherol and sterol content was unchanged. The antibacterial activity was higher, but the antifungal activity was lower than those of crude shea butter. When both fractions were mixed, their fatty acid and triacylglycerol composition were similar to those of crude shea butter, but other parameters were different.

Characterization of New Egyptian Linseed Varieties and the Effects of Roasting on Their Pigments, Tocochromanols, Phytosterols, Omega-3 Fatty Acids, and Stability.

The purpose of this study was to explore the effects of roasting linseeds on the pigment, lipid profile, bioactive components, and oxidative stability of the extracted oils. The linseed varieties Giza 11, Giza 12, Sakha 3, and Sakha 6 were roasted at 180 °C for 10 min, and the oils were extracted by cold pressing. The results showed that, after roasting, there was an increase in oil percentage and peroxide value, as well as small increases in p-anisidine and acid values. Roasting also caused an increase in chlorophyll content, while lutein and ß-carotene tend to slightly decrease, except in the Giza 11 variety. The total phenolics content was markedly enhanced after roasting. Omega-3 fatty acids were not affected by the roasting process. The total amounts of tocochromanol were found to decrease in the Giza 12 and Sakha 6 varieties after roasting. Plastochromanol-8 increased in all varieties after roasting. The phytosterol composition was minimally affected by roasting. Roasting enhanced the stability of the extracted oils, increasing the induction period and decreasing EC50 values. These results may thus help to discriminate between the different linseed varieties and serve to recommend the use of roasting to enhance the oxidative stability of extracted oil.

Chromatographic quantitation of some bioactive minor components in oils of wheat germ and grape seeds produced as by-products.

The objective of this work was to determine some beneficial and bioactive minor lipid components in wheat germ and grape seeds as a result of milling industry of wheat and pressing of grapes in wineries. Sterylglycosides (SG's) were isolated and fractionate into free and acylated SG's by TLC and were determine as their1-anthroylnitriles (1-AN) by HPLC. Moreover, 4-desmethylsterols were isolated, derivatized into their trimethyl silyl derivatives and analyzed by GLC. Tocopherols and tocotrienols were directly analyzed by HPLC. In addition, fatty acids composition by GLC was accomplished. The results were compared to three conventional edible oils, namely, corn, sunflower and cottonseed. It was found that the wheat germ oil (WGO) and grape seed oil (GSO) contained reasonable amounts of whole sterols. Sterylglycosides fraction (SG), which have not been evaluated, it was found that the two by-products contained high amounts of SG's and they were rich in free and acylated campe/stigma SG as well as free and acylated beta-sito SG. Total tocopherols and tocotrienols components were found in very high amounts in WGO (1300 ppm) and GSO (380 ppm). It is noteworthy to mention that GSO contained significant amounts of alpha- and gamma-tocotrienols which prevent cardiovascular diseases and contained reasonable amounts of alpha- and gamma-tocopherols. On the other side, it was found that WG and GS oils were enrich in linoleic acid (omega-6), while linolenic acid (omega-3) was present in higher quantity in WGO.