Nutraceutical potential of olive pomace: insights from cell-based and clinical studies

Olive oil production yields a substantial volume of by-products, constituting up to 80% of the processed fruits. The olive pomace by-product represents a residue of significant interest due to the diverse bioactive compounds identified in it. However, a thorough characterization and elucidation of the biological activities of olive pomace are imperative to redirect its application for functional food, nutraceutical, and pharmaceutical purposes both for animals and humans. In this review, we examine data from experimental models, including immortalized human vascular endothelial cells, human corneal and conjunctival epithelial cells, human colorectal adenocarcinoma cells, non-tumorigenic human hepatoma cells, and murine macrophages alongside clinical trials. These studies aim to validate the safety, nutritional value, and pharmacological effects of olive pomace. In vitro studies suggest that biophenols extracted from olive pomace possess antioxidant, anti-inflammatory, and antiproliferative properties that could be beneficial in mitigating cardiovascular disorders, particularly atherosclerosis, hepatosteatosis, and dry-eye disease. Protective effects against dry-eye disease were confirmed in a mouse model assay. Olive pomace used in the feed for fish and poultry has demonstrated the ability to enhance animals' immunity and improve nutritional quality of meat and eggs. Human clinical trials are scarce and have revealed minimal biological changes following the consumption of olive pomace-enriched foods. However, alterations in certain biomarkers tentatively suggest cardioprotective properties. The review underscores the value of olive pomace while addressing potential drawbacks and future perspectives, with a specific focus on the need for further investigation into the animal feed and human nutritional properties of olive pomace. © 2024 Society of Chemical Industry.     

BIOACTIVE POLAR LIPIDS IN OLIVE OIL, POMACE AND WASTE BYPRODUCTS

Olive oil protects against atherosclerosis because of biologically active microconstituents. In this study, total polar lipids from olive oil, pomace, pomace oil and waste byproducts were extracted, fractionated by thin layer chromatography and tested for their bioactivity. The most active ones were further purified on high-performance liquid chromatography, and the resulting lipid fractions were tested for their bioactivity. Bioactive compounds were determined in all samples with the exception of olive pomace oil. These lipids inhibited platelet-activating factor (PAF)-induced platelet aggregation and also induced platelet aggregation. The bioactive compound from olive pomace has been chemically characterized as a glycerylether-sn-2-acetyl glycolipid based on mass spectra. Chemical determinations and mass spectrometry data reinforce the assumption that these active microconstituents share both similar bioactivity and common structural features. The existence of PAF antagonists in polar lipid extracts from olive oil waste by-products render them biologically valuable materials for the food industry that could be used for the production of functional foods.

PRACTICAL APPLICATIONS

Isolated bioactive polar lipids from waste by-products of the olive oil industry that act as inhibitors of platelet-activating factor (PAF) may be used for enrichment and production of foods with higher nutritional value, as PAF plays a major role in inflammatory disorders, including atherosclerosis development.     

Packaging of Olive Oil: Quality Issues and Shelf Life Predictions

Olive oil has gained much appreciation among consumers worldwide leading to increased markets as well as greater consumer expectation and thus more challenges for the relevant food sector. By understanding the product, its interactions with the environment, and the protective role of the package, decisions can be made on the barrier properties required of the packaging materials to achieve the desired shelf life. To this end, the shelf life of packaged olive oil under various storage and distribution environments can be predicted by mathematical modeling. This review examines the basic factors affecting the shelf life of olive oil in different packaging systems and describes the main oxidative degradation mechanisms for them. Since an experimental investigation to correlate the basic quality factors and the shelf life of a product is time- and effort-consuming, the use of mathematical modeling for the prediction of packaged olive oil shelf life is also discussed. In the presented works, shelf life predictions were based on the most consumer-related attributes; namely, the evolution of olive oil flavor compounds under various packaging and storage conditions. The validation of the simulations against known experimental results showed a very good correlation, confirming the value of the mathematical approach for a quick and accurate prediction of shelf life of oxidation-sensitive products.     

Packaging of Olive Oil: Quality Issues and Shelf Life Predictions

Olive oil has gained much appreciation among consumers worldwide leading to increased markets as well as greater consumer expectation and thus more challenges for the relevant food sector. By understanding the product, its interactions with the environment, and the protective role of the package, decisions can be made on the barrier properties required of the packaging materials to achieve the desired shelf life. To this end, the shelf life of packaged olive oil under various storage and distribution environments can be predicted by mathematical modeling. This review examines the basic factors affecting the shelf life of olive oil in different packaging systems and describes the main oxidative degradation mechanisms for them. Since an experimental investigation to correlate the basic quality factors and the shelf life of a product is time- and effort-consuming, the use of mathematical modeling for the prediction of packaged olive oil shelf life is also discussed. In the presented works, shelf life predictions were based on the most consumer-related attributes; namely, the evolution of olive oil flavor compounds under various packaging and storage conditions. The validation of the simulations against known experimental results showed a very good correlation, confirming the value of the mathematical approach for a quick and accurate prediction of shelf life of oxidation-sensitive products.     

Olive biophenols: novel ethnic and technological approach

Biophenols are monomeric dihydroxyaromatic moieties that are active non-nutrient components widely found in all plant-derived foodstuffs. Wizened Oinotria table olives (WOTO) and extra virgin olive oil (EVOO), both typical ethnic products of the Mediterranean food culture, are especially rich in biophenols. Table olives can be prepared by traditional methods or by technological processing involving blanching, salting and drying of mature black olives. Olive quality depends on harvesting at mature stages, infestation conditions, firmness, triacylglycerol and biophenol content. The fruit firmness and biophenol content decreases during ripening and processing whereas the triacyiglycerol content increases. Differential scanning calorimetry (DSC) was used to determine the triacylglycerol content in dried olive pulp, and to follow inoliation trends during the production of table olives and extra virgin olive oil. The DSC technique is fast, specific, reliable, uses no solvents and requires lower amounts of olive samples compared to conventional methods. After olive production, triacylglycerol quality was maintained without lipid deterioration. The total biophenol content was sufficiently large to ensure a shelf life and functional value for olive products. Biophenols in olive products demonstrate antioxidant, free-radical antagonism and anti-microbial activity, which are important for human health and well being. Technological innovation, such as EVOO from pitted olives, using ancient methods, can continue to be at the forefront of development in the olive agrifood chain. Creativity and sophisticated techniques will provide new perspectives for olive manufacturing, based on typical regional and ethnic products. The nutritional, sensory and functional enhancement of traditional olive foods, offer the potential for improving human health and well being within the context of the Mediterranean diet.     

Olive byproducts and their bioactive compounds as a valuable source for food packaging applications

Among the most important agro-industrial activities in the Mediterranean basin, olive oil production has a high impact on the economy of many Mediterranean countries. However, olive oil extraction generates huge quantities of byproducts, including leaves, pomace residues, stones and wastewater, which have severe environmental impacts mainly because of their phytotoxicity and great organic content. Olive oil byproducts are regarded as inexpensive and abundant raw materials rich in bioactive compounds with high and varied health-related activities. Several phenolic compounds and terpenoids were recovered from olive byproducts using different conventional and advanced extraction methods due to their potential to be used in food, packaging, pharmaceutical, and cosmetic industries. Recently, the use of olive byproducts and their functional compounds to enhance the functional properties of packaging systems was investigated as a sustainable strategy for food preservation, fostering the sustainability of the olive-oil chain, and promoting circular economy. In this framework, the main goals of this review are to summarize the main bioactive compounds in olive byproducts, to review the main advancements in their extraction, purification, and characterization, and finally to discuss their applications in food packaging systems as well as safety-related aspects.     

Use of Supercritical Assisted Atomization to produce nanoparticles from olive pomace extract

Olive pomace is one of the most interesting wastes containing bioactive compounds; the extraction of polyphenols can represent an innovative solution for the reduction of the environmental hazard of this solid and the simultaneous recovery of high-added value compounds. In this study, Supercritical Assisted Atomization (SAA) was employed for the encapsulation in maltodextrin of phenolic compounds extracted from olive pomace. The effect of the ratio of maltodextrin content to total solid content of the extract and drying temperature on physical characteristics, total phenolic content and antioxidant properties of the powdered product were studied. The results confirmed the efficiency of the SAA process to encapsulate phenolic compounds from olive pomace extract. Particles with average diameter of 712 nm with high total polyphenol content (105.0 ± 0.1 mg_{Caffeic Acid Equivalent/}g_{Dry Powder}) and antiradical power (98.8 ± 3.0 mg_DPPH/mL_extract) were obtained. These particles rich in bioactive compounds can be used as functional component in formulations of new food, cosmetic or pharmaceutical products.Industrial relevanceOlive pomace is considered to be a low-cost and renewable source of high-added value compounds, such as polyphenols which can be valorized by several methodologies. In this work, we assessed the efficiency of Supercritical Assisted Atomization (SAA) in order to encapsulate phenolic compounds extracted from olive pomace. The particles obtained by SAA have spherical morphology with average diameter of 712 nm. The polyphenol-rich nanoparticles produced using this technique can be potentially used in the formulation of novel food or nutraceutical products.     

Effects of monoacylglycerols on the oxidative stability of olive oil

BACKGROUND: The study of pro‐ and anti‐oxidant compounds is important for their influence on the shelf‐life and nutritional value of food. The aim of this research was to evaluate the activity of monoacylglycerols (MAG), obtained by partial saponification of a purified olive oil, added in increasing amounts to the same oil and submitted to the Rancimat test and oven test at 60 °C. Besides routine analyses, high‐performance size exclusion chromatography analysis of polar compounds was performed. RESULTS: The addition of MAG led in all cases to a significant slowdown of the oxidative processes. These trends were more evident as the oxidation went on. The purified oil added with 30 g kg^?1 of MAG after 9 days of oven test at 60 °C presented a level of oxidative degradation significantly lower than the control after only 4 days. CONCLUSION: The data showed a marked antioxidant effect of MAG in purified olive oil, contrary to what has been observed by other authors, who noticed either a pro‐oxidant or a non‐antioxidant activity of these compounds in soybean oil. A different behaviour of MAG during oxidation could depend on the different fatty acid composition of the oil matter they are added to. Copyright © 2010 Society of Chemical Industry     

Possibility of improving the quality characteristics of olive‐pomace oil and enhancing its differentiation from refined olive‐pomace oil

An investigation was carried out to evaluate the oxidative and hydrolytic degradation of 37 olive‐pomace oils marketed in southern Italy and to compare the results with those obtained from 10 deodorised olive‐pomace oils representative of large stocks of oil obtained after the final step of refining. One aim of the research was to ascertain the quality characteristics of commercial olive‐pomace oils; another was to verify whether the legally prescribed addition of virgin olive oil to refined pomace oil, so that the final product may be classified commercially as olive‐pomace oil, was actually sufficient to justify upgrading. The analytical methods used were silica gel column chromatography and high‐performance size exclusion chromatography. The data obtained showed that the final retail olive‐pomace oils had a lower degree of oxidative degradation than the refined oils, as indicated by the lower values obtained when summing the proportions of triglyceride oligopolymers and oxidised triglycerides. Conversely, hydrolytic degradation, which was evaluated by determining diglycerides, proved to be the same in the two categories of oil. The proportions of virgin olive oil added are small, as indicated by the statistically indistinguishable values of triglyceride oligopolymers and free fatty acids obtained. The possibility of setting a limit to the amount of triglyceride oligopolymers present in the commercial category of olive‐pomace oil has been considered. This limit would ensure standardisation of the level of oxidation and, consequently, of the quality of marketed oils and would enhance differentiation between olive‐pomace oil and refined olive‐pomace oil. © 2000 Society of Chemical Industry     

Applications of Wine Pomace in the Food Industry: Approaches and Functions

Winemaking generates large amounts of wine pomace, also called grape pomace. This by‐product has attracted the attention of food scientists and the food industry, due to its high content in nutrients and bioactive compounds. This review mainly focuses on the different published approaches to the use of wine pomace and its functions in the food industry. Traditionally, wine pomace has been used to obtain wine alcohol, food colorings, and grape seed oil. More recently, research has focused in the production of other value‐added products, such as extracts of bioactive compounds, mainly phenols, recovery of tartaric acid, and the making of flours. The most common functions associated with wine pomace products are their use as antioxidants, followed by their use as fortifying, coloring, and antimicrobial agents. These products have mainly been applied to the preparation of meat and fish products and to, a lesser extent, cereal products.     

橄榄油氧化过程中风味化合物变化

橄榄油具有良好保健功能,是较为理想食用油脂;但在贮存过程中也存在氧化变质现象;橄榄油氧化将产生对人体有毒、有害副产物,其独特风味发生劣化,产生难以接受气味。该文详细介绍橄榄油氧化机理,总结引起橄榄油风味改变的醛、酮、醇、短链脂肪酸等氧化产物。     

Virgin Olive Oil as Frying Oil

Frying is one of the oldest cooking procedures and is still among the most popular ones for food preparation. Due to their unique sensory characteristics, fried foods are consumed often and with pleasure. During frying, part of the oil is absorbed by the food, thereby becoming part of our diet; most interestingly, in the Mediterranean area approximately 50% of total fat intake is provided by cooking fats. Olive oil is the key lipid component of the Mediterranean diet, the health‐promoting effects of which have been largely attributed to olive oil intake. Olive oil is unique among vegetable oils due to its desirable lipid profile and some of its minor components. Scientific evidence now indicates that during frying olive oil behavior is usually equal or superior to that of refined vegetable oils. Herein, an overview of virgin olive oil performance under frying is given, with special reference to the fate of olive oil microconstituents. The compositional changes of foods fried in olive oil are also reviewed and discussed in detail.     

Chemical stability of extra-virgin olive oil added with oregano essential oil

Extra virgin olive oil is highly consumed and well known for its nutritional and health benefits. However, it is fatty food highly susceptible to lipid oxidation. The objective of this study was to evaluate the preserving effect of oregano (Origanum vulgare L. spp vulgare called "oregano compacto") essential oil on physical and chemical properties in extra virgin olive oil during storage. Oregano essential oil composition was analyzed by GC-MS. This essential oil was added into extra virgin olive oil at 0.05%. The samples were stored in 3 different conditions: darkness, light exposure, and temperature (60 °C). Chemical indicators of lipid oxidation (peroxide value, p-anisidine value, conjugated dienes, free fatty acidity, and carotenoid and chlorophyll contents) were measured. High content in carvomenthol (22.52%), terpinolene (19.77%), thymol (13.51%), and γ-terpinene (10.30%) were detected in oregano essential oil. Olive oil samples without oregano essential oil stored at 60 °C and exposure at artificial light had the highest peroxide values during storage. Higher p-anisidine and K232 values after day 7 of storage were detected in temperature, darkness, and light exposure treatments. Light treatment was the main factor that degraded chlorophyll causing loss of color. The highest chlorophyll content (3.87 mg/kg) was observed in olive oil with essential oil at the end of storage. In general, olive oil samples added with oregano essential oil had lower peroxide, conjugated dienes, and p-anisidine values and higher chlorophyll and carotenoid contents during storage. Oregano essential oil retards lipid oxidation process in olive oil prolonging its shelf life. PRACTICAL APPLICATION: Oregano essential oil was and is used with the purpose of flavoring and aromatizing food. This essential oil due to its composition has shown antioxidant activity. Synthetic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) are thought to be promoters of carcinogenesis. Extra virgin olive oil is widely consumed because of its nutritional benefits and sensory properties which are very important to be preserved in the product. In this study, the oregano essential oil showed remarkable antioxidant activity in olive oil. Therefore, this essential oil could be considered for the industry as natural antioxidant not only to be used in olive oil but also in other fatty food products to substitute synthetic ones.     

Use of phenolic compounds from olive mill wastewater as valuable ingredients for functional foods

ABSTRACT

Olive mill wastewater (OMW) is a pollutant by-product from the virgin olive oil production. Its high content in phenolic compounds makes them play an important role for their use in foods, for their high antioxidant significance. The present paper gives an overview on the techniques for OMW valuable ingredient separation, focusing on the most effective ones for their use in food products as functional ingredients. We report on effective methods to recover OMW phenolics, and give several examples on the use these extracts in foods. When added into vegetable oils, their effect on retarding lipid oxidation improves the oxidative status of the product, whilst several challenges need to be faced. OMW phenolic extracts were also used in food emulsions, milk products or other model systems, showing promising results and little or no negative impact on the sensory characteristics or other properties. Their possible use as antimicrobial agents is also another promising approach, as positive results were obtained when applied in meat products. Other examples of using natural phenolic extracts from other sources are suggested also for OMW extracts, to expand their use and thus to improve the nutritional and technological quality of foods.     

Transfer of phenolic compounds during olive oil extraction in relation to ripening stage of the fruit

The transfer of phenolic compounds of Olea europaea L. cv. Arbequina variety during olive oil extraction in relation to ripening stage was investigated. The parameters of oil extraction by the Abencor system are shown together with mass balances of the products and by products from the olive oil extraction in relation to olive paste. The phenolic compounds in olive paste, pomace, oil and wastewater were identified and measured by HPLC. Throughout the study, the concentrations of simple phenols, secoiridoids and flavonoids were higher in the olive paste and pomace phases than in oil and wastewater phases. High concentrations of 4‐(acetoxyethyl)‐1,2‐dihydroxybenzene (3,4‐DHPEA‐AC) and secoiridoid derivatives such as the dialdehydic form of elenolic acid linked to 3,4‐DHPEA (hydroxytyrosol) or p‐HPEA (tyrosol) (3,4‐DHPEA–EDA, p‐HPEA–EDA, where EDA is elenolic acid dialdehyde) and an isomer of oleuropein aglycone (3,4‐DHPEA–EA, where EA is elenolic acid aldehyde) were found in olive oil, together with lignan compounds. It was observed that 3,4‐DHPEA–EDA was the most abundant polyphenol present in the wastewater phase. This indicates that biotransformation occurred during olive extraction, especially in the crushing and malaxation operations, and reflects the possible chemical changes that lead to the formation of new compounds. Moreover, the distribution of compounds showed their affinities toward different phases. Copyright © 2005 Society of Chemical Industry     

Bactericidal Activities of Health‐Promoting,Food‐Derived Powders Against the Foodborne Pathogens Escherichia coli,Listeria monocytogenes,Salmonella enterica,and Staphylococcus aureus

We evaluated the relative bactericidal activities (BA₅₀) of 10 presumed health‐promoting food‐based powders (nutraceuticals) and, for comparison, selected known components against the following foodborne pathogens: Escherichia coli O157:H7, Salmonella enterica, Listeria monocytogenes, and Staphylococcus aureus. The relative activities were evaluated using quantitative bactericidal activity [(BA₅₀ value, defined as the percentage of the sample in the assay mixture that resulted in a 50% decrease in colony forming units]. The BA₅₀ values were determined by fitting the data to a sigmoidal curve by regression analysis using concentration–antimicrobial response data. Antimicrobial activity is indicated by a low BA₅₀ value; meaning less material is needed to kill 50% of the bacteria. Olive pomace, olive juice powder, and oregano leaves were active against all 4 pathogens, suggesting that they behave as broad‐spectrum antimicrobials. All powders exhibited strong antimicrobial activity against S. aureus. The following powders showed exceptionally high activity against S. aureus (as indicated by the low BA₅₀ values shown in parentheses): apple skin extract (0.002%); olive pomace (0.008%); and grape seed extract (0.016%). Listeria bacteria were also highly susceptible to apple skin extract (0.007%). The most active substances provide candidates for the evaluation of antimicrobial effectiveness in human food and animal feed. Practical Application : Plant‐derived health‐promoting food supplements, high in bioactive compounds, are candidates for use as antimicrobials in food.     

Olive tree (Olea europaea L.) leaf as a waste by‐product of table olive and olive oil industry: a review

Research into finding new uses for by‐products of table olive and olive oil industry are of great value not only to the economy but also to the environment where olives are grown and to the human health. Since leaves represent around 10% of the total weight of olives arriving at the mill, it is worth obtaining high added‐value compounds from those materials for the preparation of dietary supplements, nutraceuticals, functional food ingredients or cosmeceuticals. In this review article, olive tree (Olea europaea L.) leaf is reviewed as being a potential inexpensive, renewable and abundant source of biophenols. The importance of this agricultural and industrial waste is emphasised by means of describing its availability, nutritional and therapeutic effects and studies conducted on this field. © 2017 Society of Chemical Industry     

The Historical Development and Nutritional Importance of Olive and Olive Oil Constituted an Important Part of the Mediterranean Diet

The olive tree (Olea europaea) is widely cultivated for the production of both oil and table olives and very significant because of its economic value. Olive and olive oil, a traditional food product with thousands of years of history, are the essential components of the Mediterranean diet and are largely consumed in the world. Beside of their economical contribution to national economy, these are an important food in terms of their nutritional value. Olive and olive oil may have a role in the prevention of coronary heart disease and certain cancers because of their high levels of monosaturated fatty acids and phenolic compounds. In addition, olives (Olea europaea L.) and olive oils provide a rich source of natural antioxidants. These make them both fairly stable against auto-oxidation and suitable for human health. The aim of this paper is to define the historical development and nutritional importance of olive and olive oil constituted an important part of the Mediterranean diet.     

特级初榨橄榄油基本质量指标及要求

目的 介绍2022年5月1日起实施的GB/T 23347—2021《橄榄油、油橄榄果渣油》,对当前市售进口特级初榨橄榄油质量情况进行评估。方法 采购20种市售标称意大利、希腊、西班牙等国进口的特级初榨橄榄油,检验酸价、过氧化值、消光系数变异值、水分及挥发物和不溶性杂质5个基础项目,对所得数据进行分析。通过与国际橄榄理事会标准的对比,讨论限量及测定方法等方面的细微差异,并说明这些项目对于橄榄油质量评估的现实意义。结果 所测样品的酸价、过氧化值、不溶性杂质3个项目均符合我国标准对该产品等级的限量要求。对比GB/T 23347—2021和国际橄榄理事会贸易标准,发现对于优质初榨橄榄油的酸价限量,国内标准比国外标准更为严格,橄榄油进口贸易需要注意这一差异。结论 2021年新颁布的GB/T23347—2021在质量要求上有所提高,消费者购买橄榄油时应优先选择“特级初榨橄榄油”。橄榄油质量初步评估需要加快时间和减少成本,检验以上5个项目为最低要求。