The effect of consecutive steps of refining on squalene content of vegetable oils

Effect of Filtration Process on Oxidative Stability and Minor Compounds of the Cold-Pressed Hempseed Oil during Storage

Cold-pressed hempseed oil (HO) has been increasingly exploited in the human diet for its excellent nutritional and healthy properties. However, it has a high content of polyunsaturated fatty acids (PUFAs) and chlorophylls, which inevitably accelerate its oxidative deterioration, especially in the presence of light. In this scenario, the filtration technology may ameliorate the oxidative stability of the oil, with positive effects on its nutritional quality and shelf life. Therefore, in this study, the oxidative stability and minor compounds of non-filtered and filtered HO (NF-HO and F-HO) were monitored over 12 weeks of storage in transparent glass bottles. F-HO showed a better hydrolytic and oxidative status than NF-HO during storage. As a result, F-HO also displayed better preservation of total MUFAs and PUFAs in the autoxidation process. Filtration consistently reduced chlorophylls, thus causing a variation in the natural color of HO. Accordingly, F-HO not only revealed an increased resistance to photooxidation but it was also suitable for storage in clear bottles within 12 weeks. F-HO predictably showed lower carotenoids, tocopherols, polyphenols, and squalene compared to NF-HO. However, filtration appeared to play a "protective role" toward these antioxidants, which had lower degradation rates in F-HO than NF-HO for 12 weeks. Interestingly, the element profile of HO was not affected by filtration and remained stable during the study period. Overall, this study may be of practical use to both producers and marketers of cold-pressed HO.

Impact of Metal Nanoparticles on the Phytochemical and Antioxidative Properties of Rapeseed Oil

The agricultural uses of nanoparticles continue to be considered as innovative methods that require more in-depth research into their impact on product quality. In our study, we investigated the effects of fertilizers containing metal nanoparticles (silver AgNPs and copper CuNPs) during the plant growth stage of winter rape cultivation, and in most experimental variants, with the exception of the (x2) application of AgNPs, we observed a decrease in the mass of one thousand seeds (MTS). The obtained result was 11.55% higher relative to the control sample in 2019, and also increased after the (x1) 4.36% and (x2) 11.11% application of CuNPS in 2020. The analyzed oxidative stability of the oil increased in both experimental years (2019-2020), with the highest values recorded after the (x1) and (x2) application of CuNPS-4.94% and 8.31%, respectively, in the first year of cultivation, and after the (x2) application of CuNPS-12.07% in the subsequent year. It was also observed that the content of polyphenols, flavonoids, squalene, tocopherols α and δ, chlorophylls, and carotenoids increased in the oil. Moreover, spectral FTIR analysis was performed on the oil samples obtained from cultivations sprayed with solutions containing Ag or Cu nanoparticles and revealed changes in several spectral regions with the maxima at ~1740, 1370, 1230, and ~1090 cm^-1. Additionally, a FTIR analysis conducted in combination with multivariate analysis allowed us to classify the studied oils into the most similar groups and to study the structure of data variability. The conducted analyses revealed that the use of nanoparticles resulted in decreased size of the produced seeds and improved antioxidative properties of rapeseed oil.

Loss in the Intrinsic Quality and the Antioxidant Activity of Sunflower (Helianthus annuus L.) Oil during an Industrial Refining Process

Minor compounds in vegetable oils are of health interest due to their powerful biological antioxidant properties. In order to extend the shelf life of sunflower oil, it is generally subjected to a refining process that can affect these desirable compounds. The main purpose of this study was to determine the effect of this chemical/physical refining process on selected minor components of sunflower oil in order to establish the nutritional quality and health properties of the oil. The oxidative stability, contents of fatty acids, tocopherols, phytosterols, reducing capacity, β-carotene, chlorophyll, and squalene were studied during six refining steps. Quantitative data showed the evolution of oil quality according to its degree of refinement. The results showed a significant decrease for all of the minor compounds analyzed, with losses in carotenoids of 98.6%, 8.5% in tocopherols, 19.5% in phytosterols and 45.0% in squalene. The highest reductions were recorded for the compounds that alter the most the visual aspects of the oil (waxes, carotenoids and chlorophylls) whereas reduction was limited for the compounds with no impact on the organoleptic quality. The losses in the compounds of health interest should be minimized by improving the refining processes and/or having a greater content of those molecules in crude oil by breeding new performing varieties.

Valorization of By-Products from Biofuel Biorefineries: Extraction and Purification of Bioactive Molecules from Post-Fermentation Corn Oil

The aim of this work was to develop innovative and sustainable extraction, concentration, and purification technologies aimed to recover target substances from corn oil, obtained as side stream product of biomass refineries. Residues of bioactive compounds such as carotenoids, phytosterols, tocopherols, and polyphenols could be extracted from this matrix and applied as ingredients for food and feeds, nutraceuticals, pharmaceuticals, and cosmetic products. These molecules are well known for their antioxidant and antiradical capacity, besides other specific biological activities, generically involved in the prevention of chronic and degenerative diseases. The project involved the development of methods for the selective extraction of these minor components, using as suitable extraction technique solid phase extraction. All the extracted and purified fractions were evaluated by NMR spectroscopic analyses and UV–Vis spectrophotometric techniques and characterized by quali-quantitative HPLC analyses. TPC (total phenolic content) and TFC (total flavonoid content) were also determined. DPPH and ABTS radical were used to evaluate radical quenching abilities. Acetylcholinesterase (AChE), amylase, glucosidase, and tyrosinase were selected as enzymes in the enzyme inhibitory assays. The obtained results showed the presence of a complex group of interesting molecules with strong potential in market applications according to circular economy principles.

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.

Effects of ethanol, activated carbon, and activated kaolin on perilla seed oil: Volatile organic compounds, physicochemical characteristics, and fatty acid composition

Perilla seed oil (PSO) has a special aromatic odor, which is unpleasant to the personal preferences of some consumers. To this end, this article evaluated the differences in volatile organic compounds (VOCs), physicochemical characteristics, and fatty acid composition of PSO treated with ethanol (PSO-EA), activated carbon (PSO-AC), and activated kaolin (PSO-AK). The results showed that in the PSO, PSO-EA, PSO-AC, and PSO-AK samples, the content of linolenic acid, oleic acid, and linoleic acid hardly changed. Among the physicochemical characteristics of the four samples, the color difference between PSO and PSO-EA was greater than the color difference between PSO and PSO-AC, PSO-AK. The three treatment methods had the greatest impact on the PSO peroxide value but had little effect on other indicators. Gas chromatography-ion mobility spectrum results identified 28 known volatiles, of which aldehydes, alkenals, alcohols, ketones, and esters were the main groups. Fingerprint analysis found that PSO had an aromatic odor, which includes 1-hexanol, hexanal, and 2-pentylfuran; the removal effect of ethanol on VOCs in PSO was better than that of activated carbon and activated kaolin. The difference between the four oil samples was found from the strength of the VOCs' signals in a two-dimensional map. From the principal components analysis and the "nearest neighbor" fingerprint analysis, it was found that PSO is generally quite different from PSO-EA, PSO-AC, and PSO-AK, while in the "nearest neighbor" fingerprint analysis, PSO-AC and PSO-AK are similar in general. In short, PSO will have better applications in the food field. PRACTICAL APPLICATION: Treatment of PSO with ethanol, activated carbon, and activated kaolin is conducive to the comprehensive utilization of edible resources. In this work, ethanol, activated carbon, and activated kaolin were used to remove VOCs in PSO, and PSO-EA, PSO-AC, and PSO-AK were obtained. The perilla seed oil after these three treatment methods was tested for VOCs, physicochemical characteristics, and fatty acid composition. They can meet the needs of more consumers without affecting the fatty acid composition in the PSO, and have broad development prospects.

Antibacterial Activity of a Fractionated Pistacia lentiscus Oil Against Pharyngeal and Ear Pathogens, Alone or in Combination With Antibiotics

Previous studies have clearly demonstrated that the addition of lentisk oil (LO) to streptococcal cultures makes it possible to differentiate Streptococcus spp. into three categories with Streptococcus mitis and Streptococcus intermedius sensitive, Streptococcus pyogenes, Streptococcus agalactiae, and Streptococcus mutans partially sensitive, and Streptococcus salivarius insensitive to the product. We have investigated here whether the winterization of LO, an easy and cheap procedure that removes some of the fatty substances contained within, resulted in a better antimicrobial effect on human pathogens affecting the pharyngeal mucosa and middle ear such as S. pyogenes, S. pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae, without affecting, or minimally affecting, S. salivarius strains, oral probiotics commonly used to reduce oral and middle ear infection recurrence, especially in children. Our results not only demonstrated a stronger antimicrobial action of winterized LO (WLO) on S. pyogenes, compared to what was seen with LO, but also demonstrated a strong antimicrobial action vs. S. pneumoniae and M. catarrhalis and a very limited effect on S. salivarius (strains K12 and M18). Moreover, WLO demonstrated a co-acting action when tested along with the antibiotics amoxicillin (A) and amoxicillin clavulanate (AC), effects clearly visible also on H. influenzae. Our results also showed that at least part of the antimicrobial effect observed was due to the presence of anacardic acids (AAs). Finally, WLO, when tested with human peripheral blood mononuclear cells (h-PBMCs), reduced the release of IL-6 and TNF-α and, in the case of cells stimulated by LPS, the release of IFN-γ. In conclusion, our study highlights an enhanced antimicrobial role for LO when winterized, suggests a co-acting effect of this when given with antibiotics, identifies AAs as possible active ingredients, and proposes a possible anti-inflammatory role for it.

Evaluation of Chemical and Nutritional Changes in Chips, Chicken Nuggets, and Broccoli after Deep-Frying with Extra Virgin Olive Oil, Canola, and Grapeseed Oils

The aim of this study was to assess the food nutritional profiles of potato chips, chicken nuggets, and broccoli and their palatability after deep-frying with different oils. The trials consisted of 4 cycles of deep-frying at 180°C for 4 minutes using extra virgin olive oil (EVOO), canola, and grapeseed oils. Samples of food and oils were taken untreated and after the treatments for sensorial and chemical analysis. EVOO and canola oil deep-fried food were preferred by their colour, but canola fried food was disliked because of its flavour. Results showed that there is a transference between food and oils regarding fatty acid profile and antioxidant content as well as trans fatty acids (TFAs) and polar compounds (PCs). All food presented more antioxidants and monounsaturated fatty acids after having been cooked with EVOO than after cooking with canola and grapeseed oils. Highest PCs in food were found when using canola oil and grapeseed oils. EVOO was shown to decrease the PCs in chips and chicken nuggets. PCs were not detected in raw broccoli, and broccoli cooked in EVOO showed the lowest PCs content. Canola and grapeseed oils increased the TFAs in food, whereas EVOO decreased the TFAs in the chips and maintained the initial TFAs levels in chicken nuggets and broccoli. This study shows that EVOO improves the nutritional profile of the food when compared with canola and grapeseed oils when deep-frying without any negative impact on palatability or appearance.

How should we judge edible oils and fats? An umbrella review of the health effects of nutrient and bioactive components found in edible oils and fats

Dietary guidelines for many Western countries base their edible oil and fat recommendations solely on saturated fatty acid content. This study aims to demonstrate which nutritional and bioactive components make up commonly consumed edible oils and fats; and explore the health effects and strength of evidence for key nutritional and bioactive components of edible oils. An umbrella review was conducted in several stages. Food composition databases of Australia and the United States of America, and studies were examined to profile nutrient and bioactive content of edible oils and fats. PUBMED and Cochrane databases were searched for umbrella reviews, systematic literature reviews of randomized controlled trials or cohort studies, individual randomized controlled trials, and individual cohort studies to examine the effect of the nutrient or bioactive on high-burden chronic diseases (cardiovascular disease, type 2 diabetes mellitus, obesity, cancer, mental illness, cognitive impairment). Substantial systematic literature review evidence was identified for fatty acid categories, tocopherols, biophenols, and phytosterols. Insufficient evidence was identified for squalene. The evidence supports high mono- and polyunsaturated fatty acid compositions, total biophenol content, phytosterols, and possibly high α-tocopherol content as having beneficial effects on high-burden health comes. Future dietary guidelines should use a more sophisticated approach to judge edible oils beyond saturated fatty acid content.

Exploring the potentials of underutilized grain amaranth (Amaranthus spp.) along the value chain for food and nutrition security: A review

The burden of malnutrition in Africa calls for deeper exploration of underutilized species which are rich in nutrients and have the potential to reduce food and nutrition insecurity. The common staple crops are not able to meet daily requirements for both macro- and micro-nutrients. In order to lessen this burden; protein, calorie and micronutrient deficiencies must be properly addressed for optimal growth and development to be attained. African indigenous underutilized vegetables can play a significant role in the food security of vulnerable groups like under-five children and women in both urban and rural settings. The potential of grain amaranth in meeting the nutrition needs of humans has remained a subject of interest in scientific research. Amaranth is considered one of the most commonly produced and consumed indigenous vegetables on the African continent with high nutritional potentials but yet to be fully exploited. This review therefore aims at discussing the current knowledge of the inherent potentials of grain amaranths, its current application in the food industry and proposes a framework for actions and partnerships required to scale up and improve amaranth value chain.

Changes of physicochemical properties, oxidative stability and cellular anti-inflammatory potentials for sea-buckthorn pulp oils during refining

The impact of the refining process on physicochemical properties, oxidative stability and cellular anti-inflammatory potentials of sea-buckthorn pulp oil (SBO) was investigated in this study. The results showed that acid and peroxide values of the tested SBOs decreased significantly after the refining process, while oxidative stability index (OSI) and anti-inflammatory potentials, measured as reduction in cellular inflammatory cytokine production, increased significantly. Interestingly, bleaching caused an unexpected increase in tocopherols as well as the greatest reduction in polycyclic aromatic hydrocarbons (PAHs). According to correlation analyses, tocopherol concentrations were significantly and positively correlated with OSI values and cellular anti-inflammatory potentials, while PHAs were negatively correlated with these factors. In general, refining is an effective way to improve the oxidative stability and anti-inflammatory capacity of SBO.

The impact of the refining process on physicochemical properties, oxidative stability and cellular anti-inflammatory potentials of sea-buckthorn pulp oil (SBO) was investigated in this study.

Hexane extract of green tea (Camellia sinensis) leaves is an exceptionally rich source of squalene

Squalene is a cancer chemo-preventive and skin protective agent with high commercial demand. Here, we report for the first time that the green tea (Camellia sinensis) leaves is a surprisingly rich plant-based source of squalene. Young and tender leaves and old and turf leaves were collected at four different collecting seasons (April-August). Lipophilic compounds in the leaves and commercial green teas were extracted with hexane. The squalene contents in the hexane extracts varied greatly with the types of the leaves and collecting seasons. The hexane extract of turf leaves contained significantly higher contents of squalene than the extract of tender leaves. The hexane extract of the turf leaves collected in August contained the highest content of squalene (29.2 g/kg extract). This represents the first report on the qualitative and quantitative information on squalene in green tea leaves.

Nutritional and other health properties of olive pomace oil

Olive-pomace oil is rich in oleic acid, and thus it can be an interesting dietary fat alternative as it can allow reaching the recommendation of consuming 20% of total diet energy in the form of monounsaturated fatty acids. In addition, olive-pomace oil also contains a wide range of minor components that may contribute to its healthy properties. The major components identified with healthy properties are triterpenic dialcohols and acids, squalene, tocopherols, sterols, fatty alcohols and phenolic compounds. The refining process, that the crude pomace-oil must undergo for commercial purposes, significantly reduces the content of phenolic compounds, while the other minor components remain at concentrations which can induce positive health effects, especially on cardiovascular health, outstanding pentacyclic triterpenes and aliphatic fatty alcohols in olive-pomace oil. Numerous in vitro and preclinical studies support that mainly the pure compounds, or extracts isolated from plant sources, play an important role in preventing cardiovascular disease and risk factors. Likewise, tocopherols, squalene and phytosterols, in addition to the minor fraction of phenolic compounds, have shown high biological activity with particular association to the cardiovascular function. In the light of the foregoing, and taking into consideration the absence of clinical studies with olive-pomace oil, it would be of great interest to develop randomized, crossover, controlled, double-blind studies to extend the knowledge and understanding on the health effects of olive-pomace olive.

Nutritional profile and nutraceutical components of olive (Olea europaea L.) seeds

Olive seeds, a potential food by-product from both table olive and olive oil industries, were examined for their overall proximate composition, oil, protein, mineral and phenolic components. Proximate analysis indicates that olive seeds are an unusually rich source of total dietary fibre (≅ 47% dry weight basis, DWB), as well as lipids (≅ 30%) and proteins (≅ 17%). Oil composition shows high levels of oleic (≅ 62% of total fatty acids) and linoleic (≅ 24%) acids, moderate concentrations of tocopherols (≅ 460 mg/kg) and squalene (≅ 194 mg/kg), and relatively high amounts of several sterols and non-steroidal triterpenoids. Olive seed proteins are a rich source of essential amino acids (about 46% of the total AA content). Olive seeds also contain significant amounts of some essential macro-elements (K, Ca, Mg, Na, P) and micro-elements (Zn, Mn, Cu). Phenolic compounds are present at relatively high quantities (≅ 2.8 mg/g seed, DWB); the most abundant belong to the group of secoiridoid compounds (elenolic acid derivatives) including oleuropein and structurally related substances (demethyloleuropein and ligstroside), and nüzhenide derivatives. Based on the general nutritional profile and nutraceutical components, olive seeds have value-added potential as a source of edible oil, proteins or meal serving as feed supplements.

Use of Natural Components Derived from Oil Seed Plants for Treatment of Inflammatory Skin Diseases

The incidence of inflammatory skin diseases is increasing, so the search for relevant therapeutics is of major concern. Plants are rich in phytochemicals which can alleviate many symptoms. In this review, we concentrate on compounds found in the seeds of widely cultivated plants, regularly used for oil production. The oils from these plants are often used to alleviate the symptoms of inflammatory diseases through synergetic action of unsaturated fatty acids and other phytochemicals most commonly derived from the terpenoid pathway. The knowledge of the chemical composition of oil seeds and the understanding of the mechanisms of action of single components should allow for a more tailored approach for the treatment for many diseases. In many cases, these seeds could serve as an efficient material for the isolation of pure phytochemicals. Here we present the content of phytochemicals, assumed to be responsible for healing properties of plant oils in a widely cultivated oil seed plants and review the proposed mechanism of action for fatty acids, selected mono-, sesqui-, di- and triterpenes, carotenoids, tocopherol and polyphenols.

Current Insights into the Biological Action of Squalene

Squalene is a triterpenic compound found in a large number of plants and other sources with a long tradition of research since it was first reported in 1926. Herein a systematic review of studies concerning squalene published in the last 8 years is presented. These studies have provided further support for its antioxidant, anti-inflammatory, and anti-atherosclerotic properties in vivo and in vitro. Moreover, an antineoplastic effect in nutrigenetic-type treatments, which depends on the failing metabolic pathway of tumors, has also been reported. The bioavailability of squalene in cell cultures, animal models, and in humans has been well established, and further progress has been made in regard to the intracellular transport of this lipophilic molecule. Squalene accumulates in the liver and decreases hepatic cholesterol and triglycerides, with these actions being exerted via a complex network of changes in gene expression at both transcriptional and post-transcriptional levels. Its presence in different biological fluids has also been studied. The combination of squalene with other bioactive compounds has been shown to enhance its pleiotropic properties and might lead to the formulation of functional foods and nutraceuticals to control oxidative stress and, therefore, numerous age-related diseases in human and veterinary medicine.

Characterisation of seed oils from different grape cultivars grown in China

To explore the potential of the large amount of grape pomace in wineries of China, oils of three Eurasian grape cultivars (Chardonnay, Merlot and Carbernet Sauvignon) and two Chinese traditional grape cultivars (Vitis amurensis and Vitis davidii), were characterised. The results showed seed oil properties differ for various grape varities. Grape seed oils were demonstrated to be good sources of polyunsaturated fatty acid (PUFA) (63.88-77.12 %), sterols (227.99-338.83 mg/100 g oil) and tocotrienols (320.08-679.24 mg/kg oil). Seed oil of V. amurensis exhibited the highest values of polyunsaturated fatty acid, total tocotrienols, total tocols and DPPH· scavenging capacity. Seed oil of Carbernet Sauvignon had the highest contents of squalene, total sterols, total tocopherols and total phenolics. Principal component analysis five grape cultivars differentiated on the basis of bioactive components content and antioxidant properties.

Methods for obtaining and determination of squalene from natural sources

Squalene is a natural dehydrotriterpenic hydrocarbon (C30H50) with six double bonds, known as an intermediate in the biosynthesis of phytosterol or cholesterol in plants or animals. We have briefly reviewed the natural sources for squalene and focused on the main methods and techniques to obtain and to determine it. Some of its applications in different fields of human activity are also mentioned.

Antioxidants in Greek Virgin Olive Oils

Greece is ranked third after Spain and Italy in virgin olive oil production. The number of Greek olive cultivars-excluding clonal selections-is greater than 40; however, more than 90% of the acreage is cultivated with 20 cultivars, adapted to a wide range of environmental conditions. Greek virgin olive oils, produced mainly with traditional, non-intensive cultivation practices, are mostly of exceptional quality. The benefits of consuming virgin olive oil, originally attributed to its high oleic acid content, are now considered to be the combined result of several nutrient and non-nutrient phytochemicals. The present work summarizes available data regarding natural antioxidants in Greek virgin olive oils (VOO) namely, polar phenolic compounds, tocopherols, squalene, and triterpenic acids. The literature survey indicated gaps in information, which should be filled in the near future so that the intrinsic properties of this major agricultural product of Greece will be substantiated on a solid scientific basis.