Stability of Bioactive Compounds in Olive-Pomace Oil at Frying Temperature and Incorporation into Fried Foods

The stability of minor bioactive compounds in olive-pomace oils (OPOs) was evaluated at frying temperature under the conditions of a thermoxidation test. Bioactive compounds analyzed included squalene, tocopherols, sterols, triterpenic acids and alcohols, and aliphatic alcohols. In order to determine the amount of OPO bioactive compounds incorporated into foods after frying, three different kinds of frozen products were selected, i.e., pre-fried potatoes (French fries), pre-fried battered chicken nuggets, and chicken croquettes (breaded patties), and were used in discontinuous frying experiments. Results obtained in both the thermoxidation and frying studies showed high stability of triterpenic alcohols (erythrodiol and uvaol), oleanolic acid, and aliphatic alcohols, naturally present in OPOs. In all fried foods, the content of lipids increased after frying, as expected, although the extent of absorption of OPOs into fried foods and the exchange with food lipids depended on the food characteristics. Overall, frying with OPOs improved the nutritional properties of all products tested by increasing the level of oleic acid and by the incorporation of squalene, triterpenic acids and alcohols, and aliphatic alcohols, in significant quantities.

Water Stress, Irrigation and Concentrations of Pentacyclic Triterpenes and Phenols in Olea europaea L. cv. Picual Olive Trees

Pentacyclic triterpenes and phenols are two types of bioactive molecules found in olive trees that have important activities related to health and disease prevention. Triterpenes, including oleanolic acid, maslinic acid, erythrodiol and uvaol, show antitumoral activities, and phenols such as oleuropein, tyrosol, and hydroxytyrosol are natural antioxidants. The concentration of these metabolites is considered a marker of the quality of olives and olive oil. In recent years, a lack of rain water has caused important economic losses relating to olive trees grown in Jaén, Spain. In this work, we investigated the effect of water stress by drought on the concentration of pentacyclic triterpenes and phenols in the fruits, leaves, stems and roots of cv. Picual olive trees, by comparing the concentration found in water-stressed versus irrigated plants. We used HPLC-UV/Vis and HPLC-MS to identify and determine the concentration of each individual compound. Our results showed that important changes in the concentration of these compounds are produced in response to water stress in different organs. The total content of most of these compounds in the fruits was significantly reduced, affecting their quality and production.

Analysis of bioactive minor compounds in three olive oils from varieties of olive tree eastern Algerian (Bouricha, Limli and Blanquette).

The study of bioactive compounds on the health of the unsaponifiable fraction of three olive oils from three cultivars of eastern Algeria carried out by gas chromatography revealed the presence of 11 compounds with the predominance of b-Sitosterol, Sterol characteristic of olive oils and having a nutritional and pharmacological value. The highest content was found in Limli oil (81.59%). Two triterpene dialcohols were chromatographed with sterols (erythrodiol and uvaol), the content of which can be identified fraud and to detect whether the virgin oil is mixed with the oil of pomace. Analysis of the alcohol fraction by GPC-FID revealed the predominance of a triterpene alcohol, 24-methylene cycloarenol for the three varieties with a higher content for Blanquette (48.03%) followed by cycloarenol. For the aliphatic alcohols, the analysis shows the predominance of four alcohols with 22, 23, 24 and 28 carbon atoms whose contents are higher for Limli oil. The spectrophotometric determination of antioxidant pigments shows that Limli oil is richer in chlorophylls with an average of 13.53 mg / kg and a significantly higher carotenoid content for Bouricha and Limli (13.10 -12.82 mg / Kg). The total polyphenols were lower for Blanquette (83.36 mg / kg) compared with Bouricha and Limli (133.3 mg / kg and 121.3 mg / kg), making them more stable during oxidation storage and whose beneficial effects of olive oil are mainly attributed to these substances, in particular the antioxidant action that would protect against diseases of oxidative stress.

A highly automated method for simultaneous determination of sterols, erythrodiol and uvaol in olive oils

In this work, we presented a highly automated method for the simultaneous analysis of sterols, erythrodiol and uvaol in olive oils with the use of gel permeation chromatography (GPC), an automatic solvent evaporator and LC-MS.