Characterization of the Triacylglycerol Fraction of Italian and Extra-European Hemp Seed Oil

Hemp seed oil (HSO) has received considerable attention for its health properties, especially due to unsaturated fatty acid (UFA) content. In this work, the triacylglycerol (TAG) fraction of Italian and Extra-European HSO was characterized by applying an enzymatic approach, based on the use of pancreatic lipase and sn-1,2-diacylglycerol kinase. This procedure allows determination of the intrapositional FA% composition of TAG. The results of the stereospecific analysis are useful for deepening knowledge on HSO nutritional aspects. The high percentage of UFA (88.3–89.9%), in particular essential FA (74.4–85.9%), of HSO samples in sn-2 position is important for long-term health effects, but also to enhance the use of this oil as a functional ingredient in food, cosmetic and nutraceutical fields. Furthermore, the results of total and intrapositional FA % compositions, subjected to principal component analysis, were able to differentiate HSO Italian samples from Extra-European ones. Based on the obtained results, it can be stated that the stereospecific analysis represents a potent analytical tool providing the fingerprint of TAG fraction, useful to highlight possible chemical descriptors for HSO authenticity and traceability purposes.

New insights into the digestion and bioavailability of a high-melting-temperature solid triacylglycerol fraction in bovine milk fat

Clarifying the health risks associated with the consumption of high-melting-temperature solid triacylglycerol (TAG) from milk fat has profound significance for the nutritional evaluation and development of new dairy products. Our...

Oxidation of Olive Oil under Still Air

This work was conducted to analyse the effect of different exposed areas/mass ratios on oil oxidation. Different volumes of the triacylglycerol portion of purified olive oil were placed in glass vials with the same air-exposed area, and stored at 38°C in the dark under still air. The oxidation process was evaluated by determining the peroxide index, K232 and K270 extinction coefficients, fatty acid composition, polar compounds (PCs) and composition of triacylglycerols over time. Substantial differences in the oxidation rate as a function of the air-exposed area to triacylglycerol fraction-mass ratio were observed. The peroxide index exponential increase with time was correlated to the air-exposed area/triacylglycerol fraction mass ratio and the oxidation induction period. Less oxidation derived by-products per gram of triacylglycerols were observed for smaller air-exposed area/triacylglycerol fraction mass ratios. The oxidation process followed an apparent first order chemical reaction. Correlations of the evolution patterns among the various oxidation by-products were also reported.

Absorption of very-long-chain saturated fatty acids in totally hydrogenated fish oil

Partially hydrogenated fish oil (PHFO) contains a high amount of trans fatty acids (TFA). Total hydrogenation results in a minimal amount of TFA, but a high content of very-long-chain saturated fatty acids (VLCSFA). Absorption and metabolism of VLCSFA from totally hydrogenated fish oil (THFO) were studied in rats. Groups of eight rats were fed one of four diets containing 40 g soyabean oil (SBO)/kg (low-fat diet), 150 g SBO/kg (SBO diet), 40 g SBO+110 g PHFO/kg (PHFO diet) or 40 g SBO+110 g THFO/kg (THFO diet) for 4 weeks. A lower absorption coefficient of the fat content was found in the THFO group (61 %) compared with the other groups (PHFO 95 %, SBO 99 %, low fat 98 %; P<0·05), which was mainly due to reduced absorption of VLCSFA. A reduced weight gain was found for the THFO group compared with the other groups, but this was only significant when compared with the SBO group (P<0·05). Faecal fat excretion (dry weight) was markedly increased in the THFO group (47 %), which was 2·4, 4·8 and 8·3 times higher compared with the groups fed PHFO, SBO and low-fat diets (P<0·05), respectively. Serum total cholesterol was reduced for the PHFO and THFO groups (P<0·05), whereas serum triacylglycerol was increased for the PHFO group compared with the other groups (P<0·05). Animals fed THFO diet had an increased content of 20:0 and 22:0 in the serum triacylglycerol fraction (P<0·05), whereas only 20:0 was increased in the serum phospholipid fraction (P<0·05). The low absorption coefficient of THFO must be considered if this fat is to be used for consumption by animals or man.