The Nutraceutical Value of Olive Oil and Its Bioactive Constituents on the Cardiovascular System. Focusing on Main Strategies to Slow Down Its Quality Decay during Production and Storage

Cardiovascular diseases represent the principal cause of morbidity and mortality worldwide. It is well-known that oxidative stress and inflammatory processes are strongly implicated in their pathogenesis; therefore, anti-oxidant and anti-inflammatory agents can represent effective tools. In recent years a large number of scientific reports have pointed out the nutraceutical and nutritional value of extra virgin olive oils (EVOO), strongholds of the Mediterranean diet, endowed with a high nutritional quality and defined as functional foods. In regard to EVOO, it is a food composed of a major saponifiable fraction, represented by oleic acid, and a minor unsaponifiable fraction, including a high number of vitamins, polyphenols, and squalene. Several reports suggest that the beneficial effects of EVOO are linked to the minor components, but recently, further studies have shed light on the health effects of the fatty fraction and the other constituents of the unsaponifiable fraction. In the first part of this review, an analysis of the clinical and preclinical evidence of the cardiovascular beneficial effects of each constituent is carried out. The second part of this review is dedicated to the main operating conditions during production and/or storage that can directly influence the shelf life of olive oil in terms of both nutraceutical properties and sensory quality.

Trophic upgrading and mobilization of wax esters in microzooplankton

Heterotrophic protists play pivotal roles in aquatic ecosystems by transferring matter and energy, including lipids, from primary producers to higher trophic predators. Using Oxyrrhis marina as a model organism, changes to the non-saponifiable protist lipids were investigated under satiation and starvation conditions. During active feeding on the alga Cryptomonas sp., the O. marina hexane soluble non-saponifiable fraction lipid profile reflected its food source with the observed presence of long chain mono-unsaturated fatty alcohols up to C25:1. Evidence of trophic upgrading in O. marina was observed with long chain mono-unsaturated fatty alcohol accumulation of up to C35:1. To the best of our knowledge, this is the first evidence that heterotrophic dinoflagellates are capable of producing ester derived alcohols and that dinoflagellates like O. marina are capable of synthesizing fatty alcohols up to C35. Additionally, we show evidence of trophic upgrading of lipids. During a 20-day resource deprivation, the lipid profile remained constant. During starvation, the mobilization of wax esters as energy stores was observed with long chain fatty alcohols mobilized first. Changes in lipid class profile and utilization of wax esters in O. marina provides insight into the types of lipids available for energy demand, the transfer of lipids through the base of marine food webs, and the catabolic response induced by resource deprivation.

Gas Chromatographic Assay of Supplemental Vitamin E Acetate Concentrates: Collaborative Study

A gas chromatographic (GC) method for determination of supplemental a-tocopheryl acetate in high potency vitamin £ powders and oils was collaboratively studied as an alternative to the AOAC colorimetric method (43.147-43.151, Emmerie-Engel), which requires saponification, extraction of the saponifiable fraction, and quantitation by colorimetry. The simpler GC procedure requires only extraction and/or enzymatic digestion and dilution before quantitation. Six blind duplicates were distributed to 10 laboratories; all 10 returned results. Repeatability (sr) and reproducibility (sR), % vitamin E/g, for the feed oil concentrates was 1.1 and 1.3, respectively; for the feed adsorbates 1.0 and 1.5; and for the spray-formulated powders 1.4 and 1.3. These results compare favorably with results obtained in a comparison study of the GC and Emmerie-Engel methods conducted by BASF in 1985. The method has been approved interim official first action for determination of a-tocopheryl acetate in vitamin E acetate concentrates as an alternative for those products only to AOAC colorimetric method 43.147-43.151

ASCORBIC ACID METABOLISM IN SWINE. THE EFFECTS OF FREQUENCY OF FEEDING AND LEVEL OF SUPPLEMENTARY ASCORBIC ACID ON SWINE FED VARIOUS ENERGY LEVELS

The effects of supplementary ascorbic acid and frequency of feeding on the performance of 3-wk-old, castrated, male swine fed 140, 240 and 340 kcal/kg W0.75 of metabolizable energy (ME) was investigated using a 3 × 3 × 2 factorial experiment. Frequency of feeding had no influence on the growth rate within any one energy group. Supplementary ascorbic acid up to the level of 1,000 mg per day produced improvement in growth rates at all levels of ME intake. The improvement in rate of growth appeared not to be due to water retention because there were no differences in creatinine excretion rates (per kg of body weight per day) between any of the groups. Ascorbic acid supplementation at the rate of 1,000 mg/day resulted in an increased proportion of the label from glucose-U-14C incorporated into the saponifiable fraction of an adipose tissue biopsy from the group fed a daily ration of 140 kcal ME/kg W0.75 in five equal amounts during the day. Supplementary ascorbic acid appeared to have no other effects on lipid metabolism. Excretion of ascorbic acid was significantly increased when there was an increased ME intake and an increased level of vitamin supplementation. These observations confirm an earlier report that the ascorbic acid available to the swine is a function of the energy level in the diet. It is suggested that observations (vide supra) made in ME-deprived animals may be due to decreased amounts of ascorbic acid physiologically available to the pig.

Sterol biosynthesis in the free-living nematode Panagrellus redivivus

The fate of the known sterol precursor squalene 2,3-oxide was investigated in the free-living nematode Panagrellus redivivus. The nematodes were cultured axenically in the presence of [4-3H]squalene 2,3-oxide. Radioactivity was found in the total lipids of the isolated nematodes. Essentially all of the radioactivity encountered in the total lipids was found in the non-saponifiable fraction. The components present in the non-saponifiable fraction were separated and isolated by t.l.c. Three labelled components were identified by a combination of t.l.c., g.l.c. and mass spectroscopy. It is established that P. redivivus has the capacity for biosynthesis of lanosterol. No labelled C27 sterols could be detected.

Induction of orientation of bacterial cellulose microfibrils by a novel terpenoid from Acetobacter xylinum

1. The bacterium Acetobacter xylinum produces extracellular cellulose microfibrils that form a pellicle in the medium enmeshing the bacterial cells. These microfibrils may show some localized alignment, which can be seen as birefringence when the culture is viewed between crossed Polaroid sheets. 2. An increase in birefringence can be induced by the addition of small amounts of certain classes of lipids, particularly sterols, to the cultures. 3. A crude lipid extract from Acetobacter cells induced greatly increased birefringence when added to fresh cultures of this organism. 4. When the bacterial lipids were fractionated, most of the activity was recovered in a complex, polar lipid. The lipid is secreted into the medium during growth and is unstable. The non-saponifiable portion of this lipid is shown to be a 1:1 mixture of a saturated and a monounsaturated C35 tetrahydroxy terpene with a hopane ring system in the accompanying paper by Förster et al. (1973). The saturated molecule is referred to as tetrahydroxybacteriohopane. 5. Tetrahydroxybacteriohopane is itself capable of inducing birefringence in cultures as is 22-hydroxyhopane, which was also isolated from the non-saponifiable fraction of the total lipids. 6. The mechanism of induction of birefringence (orientation of microfibrils) is not known. This is unlikely to be a specific effect, since all the above compounds are active (intact lipid, tetrahydroxybacteriohopane, 22-hydroxyhopane), as are other classes of lipid. It is suggested, however, that a common mechanism may be involved and that similar compounds may be concerned with control of microfibril alignment in the cells of higher plants.

ACETATE METABOLISM IN MYCOBACTERIA

Acetate-1-14C was added to the culture medium of different species of mycobacteria in the exponential phase of growth. Analyses after incubation for 2 hours showed that acetate was utilized for the synthesis of various lipid fractions, and also converted into carbon dioxide. Mycobacterium tuberculosis strains, in contrast to saprophytic mycobacteria, showed preferential utilization of acetate for oxidation over utilization for lipid synthesis. In the virulent strain of M. tuberculosis a greater proportion of the total radioactivity in lipids was present in the non-saponifiable fraction than in other mycobacteria, including M. tuberculosis H37Ra.