Search Results (136)

Exhausted olive oil pomace (EOP), Fucus spiralis, and Limnospira sp. extracts—rich in bioactives, polysaccharides, or proteins—were incorporated into alginate-based edible coatings and applied to strawberries to evaluate their effects on postharvest quality parameters, including decay, weight loss, color, antioxidant activity, and microbial growth. Among the tested formulations, the EOP-based coating (0.25% bioactive rich-extract) was the most effective, reducing weight loss to approximately 18% after 10 days at 10 °C, compared with higher losses in the control and other coatings, while also better preserving color through higher hue and chroma retention. Antioxidant activity, measured by ABTS and DPPH assays, was consistently higher in EOP-coated strawberries, despite a general decline in total phenolic content across treatments. Specifically, ABTS values decreased from 21.43 ± 0.90 (day 0) to 12.88 ± 0.39 (day 10) mmol TE/100 mg DW, while DPPH values declined from 10.23 ± 1.39 (day 0) to 5.96 ± 1.03 (day 10) mmol TE/100 mg DW. Microbial analyses further showed that the EOP coating strongly inhibited spoilage fungi, yeasts, and bacteria, whereas coatings containing Fucus spiralis or Limnospira sp. extracts (0.25% bioactive rich-extract plus 0.5% polysaccharide- or protein-rich extract) offered only moderate protection and, in some cases, promoted microbial growth. Overall, the EOP coating demonstrated superior performance in maintaining freshness, delaying microbial spoilage, and extending the shelf life of strawberries, highlighting its potential as a sustainable and functional strategy for fruit preservation. Full article

Pistacia terebinthus L. which has been traditionally used in diet and medicine, remains underexplored in Greece, particularly regarding its chemical composition and antioxidant activity. The current study aims to comparatively evaluate the chemical profile of cold-pressed terebinth fruit oils, obtained from wild trees growing in the Greek Island of Chios (North East Aegean Sea), harvested during three years (2019, 2020 and 2021). The oils’ lipid profile was dominated by oleic acid (C18:1 cis-9) (42–45%) followed by palmitic acid (C16:0) (24–30%) and linoleic acid (C18:2 cis-9,12) (19–22%). Their phenolic acid content, expressed as anacardic acids—known for their bioactive properties—was quantified via q-¹H-NMR and found to be markedly high (1.91–2.98 mmol/kg oil). Total phenolic content (TPC) of the fruit extract showed interesting high value (185.92 ± 2.61 mg GAE/g) accompanied by strong antioxidant activity (DPPH, exhibiting > 80% inhibition at a concentration of 100 µg/mL) which was positively correlated with TPC. Additionally, the fruits demonstrated a rich nutritional profile, particularly in crude fibers (38.9%) and essential minerals (K, Mg, and Zn), along with low sodium content, suggesting notable dietary benefits. The cold-pressed oil exhibited high lipid content and low specific extinction coefficients (K₂₃₂, K₂₇₀), indicating minimal oxidation and confirming the oil’s freshness. These findings highlight the potential of P. terebinthus fruit oil as a high-value functional raw material with nutritional and antioxidant properties. Comparable to olive oil in lipid quality, Greek turpentine fruit and oil could play a promising role towards further applications in the food, cosmetic and pharmaceutical sectors. Full article

Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) are powerful techniques that have been employed to analyze foodstuffs comprehensively. These techniques offer in-depth information about the chemical composition, structure, and spatial distribution of components in a variety of food products. Quantitative NMR is widely applied for precise quantification of metabolites, authentication of food products, and monitoring of food quality. Low-field ¹H-NMR relaxometry is an important technique for investigating the most abundant components of intact foodstuffs based on relaxation times and amplitude of the NMR signals. In particular, information on water compartments, diffusion, and movement can be obtained by detecting proton signals because of H₂O in foodstuffs. Saffron adulterations with calendula, safflower, turmeric, sandalwood, and tartrazine have been analyzed using benchtop NMR, an alternative to the high-field NMR approach. The fraudulent addition of Robusta to Arabica coffee was investigated by ¹H-NMR Spectroscopy and the marker of Robusta coffee can be detected in the ¹H-NMR spectrum. MRI images can be a reliable tool for appreciating morphological differences in vegetables and fruits. In kiwifruit, the effects of water loss and the states of water were investigated using MRI. It provides informative images regarding the spin density distribution of water molecules and the relationship between water and cellular tissues. ¹H-NMR spectra of aqueous extract of kiwifruits affected by elephantiasis show a higher number of small oligosaccharides than healthy fruits do. One of the frauds that has been detected in the olive oil sector reflects the addition of hazelnut oils to olive oils. However, using the NMR methodology, it is possible to distinguish the two types of oils, since, in hazelnut oils, linolenic fatty chains and squalene are absent, which is also indicated by the ¹H-NMR spectrum. NMR has been applied to detect milk adulterations, such as bovine milk being spiked with known levels of whey, urea, synthetic urine, and synthetic milk. In particular, T2 relaxation time has been found to be significantly affected by adulteration as it increases with adulterant percentage. The ¹H spectrum of honey samples from two botanical species shows the presence of signals due to the specific markers of two botanical species. NMR generates large datasets due to the complexity of food matrices and, to deal with this, chemometrics (multivariate analysis) can be applied to monitor the changes in the constituents of foodstuffs, assess the self-life, and determine the effects of storage conditions. Multivariate analysis could help in managing and interpreting complex NMR data by reducing dimensionality and identifying patterns. NMR spectroscopy followed by multivariate analysis can be channelized for evaluating the nutritional profile of food products by quantifying vitamins, sugars, fatty acids, amino acids, and other nutrients. In this review, we summarize the importance of NMR spectroscopy in chemical profiling and quality assessment of food products employing magnetic resonance technologies and multivariate statistical analysis. Full article

Phenolic compounds are important targets in olive breeding due to their health benefits and impact on fruit and oil quality. Fruit phenolic profiling enables efficient screening of large germplasm collections without oil extraction, but environmental variability, especially year-to-year differences, affects their expression. The aim of this study was to assess the genotypic influence on fruit phenolic composition, based on a three-year evaluation of 10 wild olive genotypes and 75 cultivars from an olive core collection. Each genotype was sampled in at least two seasons, with 1 to 3 trees analyzed annually. Variance analysis revealed significant genetic variation among cultivars and notable genotype-by-year interactions for certain phenolics. Broad-sense heritability was generally high for most compounds, although some, such as ligstroside and ligstroside aglycone, showed greater environmental sensitivity. Best linear unbiased predictions (BLUPs) were highly correlated with average relative phenotypic values. Clustering analyses identified strong associations among key phenolic compounds and highlighted distinct metabolic profiles separating wild and cultivated genotypes, reflecting differences in phenolic accumulation patterns. These findings demonstrate the genetic and environmental influences on olive fruit phenolics and provide reliable estimates to support future marker-assisted selection studies aimed at developing useful tools in olive breeding programs. Full article

Domestic food waste and agro-industrial by-products (AIBPs) occurring throughout the food chain, including production, processing, and storage, have become a global sustainability concern. Interestingly, this waste and these by-products contain a significant amount of commercially vital bioactive compounds, including polyphenols and carotenoids. Remarkably, discarded by-products such as fruit and vegetable peels contain more bioactive compounds than edible pulp. Thus, valorizing this waste and these by-products for commercially vital bioactive products can solve their disposal problems and help alleviate climate change crises. Additionally, it can generate surplus revenue, significantly improving food production and processing economics. Interestingly, several bioactive extracts derived from citrus peel, carrot pomace, olive leaf, and grape seed are commercially available, highlighting the importance of agro-food waste and by-product valorization. Considering this background information, this review aims to provide holistic information on major AIBPs; recovery methods of bioactive compounds focusing on polyphenols, carotenoids, oligosaccharides, and pectin; microencapsulation of isolated bioactive for enhanced physical, chemical, and biological properties; and their commercial application. In addition, green extraction methods are discussed, which have several advantages over conventional extraction. The concept of the circular bio-economy approach, challenges in waste valorization, and future perspective are also discussed. Full article

Background/Objectives: The agriculture sector faces significant challenges due to global climate change, environmental stressors, and rapid population growth, compounded by unsustainable farming practices. This study investigates the potential of the endophytic bacterial strain B.B.Sf.2, isolated from the bark of Salvia fruticosa and identified as Bacillus velezensis through phylogenomic analyses. Methods: To address these issues, eco-friendly techniques, such as the application of plant-associated microbes, are gaining attention. Genome mining revealed numerous secondary metabolite biosynthetic gene clusters associated with plant growth promotion, biocontrol, colonization, and defense elicitation. Results: The strain exhibited strong antagonistic activity against phytopathogens, mediated by diffusible and volatile compound production, along with plant-growth-promoting traits and environmental adaptability. Genome mining revealed numerous secondary metabolite biosynthetic gene clusters associated with plant growth promotion, biocontrol, colonization, and defense elicitation. B.B.Sf.2 effectively inhibited Colletotrichum species causing olive anthracnose and suppressed Botrytis cinerea, the gray mold pathogen, in post-harvest studies on infected fruits. Bioautography of ethyl acetate extracts demonstrated bioactivity against B. cinerea, attributed to iturin-like metabolites. The extracts maintained bioactive properties regardless of fungal interaction. Furthermore, the strain significantly promoted the growth of Arabidopsis thaliana via diffusible and volatile compounds. Conclusions: Our results highlight the multifunctional potential of B.B.Sf.2 as a biocontrol and growth-promoting agent, warranting further evaluation in field applications to enhance sustainable agriculture. Full article

Mycotoxins like aflatoxins (AFs), fumonisins (FBs), and ochratoxin A (OTA) pose serious health risks to humans and animals. Fruit pomace extracts, rich in natural nutrients and bioactive compounds, have the potential to enhance animal health and mitigate mycotoxin toxicity. This study evaluated a novel liquid anti-mycotoxin solution (LAS), a combination of grape and olive pomace extract administered to broiler chickens through drinking water (2 L:1000 L) for 1–42 days under a natural multi-mycotoxin challenge. The 42-day trial with 288 one-day-old male Ross 308AP95 chicks included four experimental groups: a negative control (NC); NC+LAS; a positive control (PC) group fed a diet containing 80 μg/kg AFs, 1600 μg/kg FBs, and 50 μg/kg OTA; and PC+LAS. The growth performance, oxidative defense genes (liver), and stress biomarkers (blood) were analyzed. Mycotoxin exposure negatively affected body weight (BW), the feed conversion ratio (FCR), and the oxidative defense mechanism. LAS supplementation improved BW and the FCR, reduced Nrf-2 expression, and enhanced mycotoxin detoxification via lower EPHX1 expression. Though the LAS did not fully restore performance to NC levels, it significantly mitigated mycotoxin-induced damage. This study concluded that the LAS is a promising solution to improve broiler resilience against moderate to high mycotoxin exposure. Full article

The endophytic strain Amfr20 was isolated from roots of the olive tree var. Amfissa. Based on core-genome phylogenomic analyses, it was classified as Bacillus velezensis. The isolate showed positive results in numerous plant growth promoting traits, as well as in abiotic stress tolerance and in colonization related traits in vitro. Furthermore, the strain exhibited antifungal activity in vitro through diffusible and volatile compounds. Whole genome analysis revealed that the strain possesses large and various arsenals of secondary metabolite biosynthetic gene clusters involved in the bioagent’s functional properties, including plant growth promotion, colonization, and plant defense elicitation, as well as having the genomic potential for abiotic stress mediation. Based on TLC-bioautography, the ethyl acetate extracts of secreted agar-diffusible compounds from Amfr20 through single and dual cultures were found to be bioactive independently of the fungal pathogen’s interaction. The bacterial endophyte also proved efficient in suppressing the severity of anthracnose olive rot and gray mold post-harvest diseases on olive fruits and table grape berries, respectively. Lastly, Amfr20 beneficially affected Arabidopsis thaliana growth under normal and saline conditions, while boosting the plant development of Solanum lycopersicum through seed biopriming and root irrigation methods. The results of this multilevel study indicate that the novel endophyte Amfr20 Bacillus velezensis is a promising bioagent that should be exploited in the future as an ecological biopesticide and/or biostimulant. Full article

The current research aims to monitor the physicochemical changes in various varieties of extra virgin olive oils (EVOOs) supplemented with exogenous polyphenolic extract from olive fruit, enriched with hydroxytyrosol (HTyr) and its derivatives, compared to numerous refined olive oils, sunflower oil, and high oleic sunflower oil under different deep-frying conditions (170–210 °C for 3 to 6 h, with/without added HTyr. Acidity, K₂₃₂, K₂₇₀, ∆K, peroxide value (PV), anisidine value (AnV), TOTOX, refractive index (RI), carotenoids, chlorophyll, and antioxidant capacity using DPPH (2,2-diphenyl-1-picrylhydrazyl) approach were evaluated. The results show that EVOO varieties generally exhibit lower acidity and thermal degradation compared to refined olive oils, particularly when deep-fried at 170 °C for 3 h with exogenous HTyr (the best treatment). Royuela, Koroneiki, Empeltre, Manzanilla, and Arbosana EVOO varieties demonstrated lower K₂₃₂ values (1.36, 1.67, 1.79, 1.82, and 1.81, respectively). Under optimal deep-frying conditions, all EVOO varieties fell within the standard K₂₃₂ limit for EVOO (≤2.5), except for Cornicabra. Regarding K₂₇₀, only Royuela (0.11) and Manzanilla (0.22) were below the standard limit of ≤0.22. These two varieties also exhibited the lowest ΔK values (0.00). The findings further revealed that Royuela, Koroneiki, and Manzanilla had the lowest TOTOX values, with 20.76, 23.38, and 23.85, respectively. Moreover, Koroneiki and Arbosana had the highest carotenoid ratios, with values of 17.5 mg/kg and 13.7 mg/kg, respectively. Koroneiki, Arbosana, and olive oil 1° also displayed the highest chlorophyll concentrations, with values of 50.2, 53.7, and 47.5 mg/kg, respectively. Furthermore, the findings from the best deep-frying treatment indicated that all olive oil categories exhibited high scavenging radical activity toward DPPH, even in refined olive oil categories and low-quality original olive oil due to the addition of HTyr. In conclusion, deep-fried EVOOs enriched with HTyr at 170 °C/3 h are thermally stable, exhibiting low hydrolysis, low oxidation, higher antioxidant potential, and stable chlorophyll and carotenoid levels. The addition of HTyr to deep-frying oils not only enhances the health benefits of EVOO, supporting EFSA health claims but also acts as a promising stabilizer for the olive oil industry, particularly under high-temperature processing conditions over prolonged periods. This highlights its potential for industrial use as a natural alternative to synthetic antioxidants, not only for olive oil but also for other edible oils, with practical applications in the food industry to improve the quality and stability of frying oils. Full article

Olive extract (OE) has been used in human foods for its nutraceutical effects, making it a product of interest for pet food. However, OE’s effect on palatability has not been examined. The study objective was to evaluate the palatability of dry cat foods with OE applied at differing inclusions within liquid or dry palatants. Twenty-seven volatile compounds were identified by gas chromatography–mass spectrometry for a potentially earthy or fruit-like flavor profile. Liquid palatants were formulated to supply 0 (control), 15, 30, 50, 75, and 150 ppm OE, and dry palatants were formulated to provide 0, 100, 200, 400, and 600 ppm OE when coated onto kibble. Palatability was evaluated using two-day, two-bowl testing of OE-containing versus control rations in adult cats (n = 20) with two-tailed t-tests to determine if OE affected intake ratio (IR). The observed IR of rations with OE were 0.45 to 0.56. The only preference was the 200 ppm treatment (IR = 0.56; p = 0.01) while the other OE rations were not different from the control (p ≥ 0.05). These findings indicate that palatant formulations can supply kibble diets with up to 150 ppm OE for liquid and 600 ppm for dry applications without negatively impacting cat food palatability. Full article

Rheumatoid arthritis (RA) is a long-term systemic autoimmune disorder that causes joint inflammation, swelling, pain, bone erosion, and deformities. Recent findings emphasize the anti-inflammatory and antioxidant properties of bioactive natural compounds, such as polyphenols extracted from plants and fruits, and their possible synergistic effect when used in combination with current therapies to improve the prognosis and symptoms of inflammatory rheumatic diseases. Here, we report that Sicilian extra virgin olive oil polyphenol-enriched extracts (PE-EVOOs) reduce intracellular reactive oxygen species (ROS) and pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-1 β (IL-1β), in peripheral mononuclear cells (PBMCs) obtained from both RA patients and healthy subjects (HSs) treated with lipopolysaccharides (LPS) as a control. HPLC-ESI-MS analysis highlighted that PE-EVOOs are rich in different polyphenolic compounds responsible for many of the observed biological effects. At molecular levels, Western blotting analyses revealed that PE-EVOO treatment is associated with the downregulation of the phosphorylated and active form of the inflammatory transcription factor NF-κB and the pro-inflammatory enzyme cyclooxygenase 2 (COX2). In addition, PE-EVOOs upregulated the transcription factor Nrf2 and its target antioxidant enzyme catalase and manganese superoxide dismutase (MnSOD). Collectively, these results suggest a possible use of PE-EVOOs as potential adjuvants for the treatment of RA. Full article

Six olive groves (three conventional and three organic) of “Koroneiki” olive cultivar were selected in two different provinces in southern Greece during a two-year trial (one province per year). At harvest, the oil was extracted from olive fruits using an Abenchor-type olive mill. Olive oil quality characteristics, including free acidity, ultraviolet absorbance indexes, peroxide value, free fatty acids, total and individual phenolic compounds, antioxidant capacity, and α-tocopherol content, were assessed. During the second year, olive oil samples were stored for 12 months, and their quality was re-evaluated. Few significant differences were observed between organically and conventionally produced olive oils, while the quality of both deteriorated significantly after storage (decrease in antioxidant capacity and major phenolic compounds, except for hydroxytyrosol and tyrosol, and increase in peroxide index value). Principal component analysis revealed that, during the first year, oils produced following organic and conventional practices could be distinguished; however, this distinction was not evident during the second year. Nevertheless, significant differentiation was found between oils produced under the same cultivation practice. In conclusion, the discrepancies found in the literature regarding organic versus conventional olive oil properties probably originate from the differences detected even among similar products (organic or conventional), including high-standard deviations. Full article

This study explores approaches to enhancing the biostability of extra virgin olive oil (EVOO) supplemented with olive fruit extract (OFE) enriched with hydroxytyrosol (HTyr). The investigation focuses on prolonged deep frying (DF) conditions at 170 °C and 210 °C, over durations ranging from 3 to 48 h, with the aim of improving sensorial attributes, polyphenolic content, and thermal oxidative stability. Parameters, such as acidity, peroxide value (PV), K₂₃₂, K₂₇₀, ΔK, phenolic compounds, and sensory attributes, were monitored. The PV did not exceed the standard limit in HTyr-EVOO at 210 °C/24 h; however, in non-supplemented EVOOs, it remained within the limits only up to 210 °C/18 h. Acidity stayed within the acceptable limit (≤0.8) at 170 °C/24 h in both enriched and non-enriched EVOOs. K₂₃₂ values were ≤2.5 in HTyr-EVOO fried at 170 °C/18 h. K₂₇₀ and ΔK did not exceed the limits in HTyr-EVOO at 170 °C/3 h, whereas they surpassed them in non-supplemented oils. Additionally, HTyr and tyrosol levels were significantly higher (p < 0.05) in HTyr-EVOOs. Phenolic compounds, including verbascoside, pinoresinol, 1-acetoxypinoresinol, and phenolic acids, such as chlorogenic, vanillic, homovanillic, 4-dihydroxybenzoic, and caffeic acids, were detected in HTyr-EVOOs. Oxidized secoiridoid derivatives increased significantly as DF progressed. Moreover, sensory analysis revealed that positive attributes in EVOOs—such as fruity, bitter, and pungent notes—decreased significantly with increasing temperature and frying duration (p < 0.05). Beyond 210 °C/6 h, these attributes were rated at zero. However, HTyr-EVOOs exhibited lower rancidity compared to non-enriched oils under identical conditions, attributed to the protective effect of HTyr. In conclusion, HTyr-EVOOs demonstrated thermal stability up to 210 °C/6 h, retaining desirable sensory qualities, higher phenolic content, and reduced degradation. These findings indicate that natural OFEs have strong potential as food additive in deep fried EVOOs, enhancing sensory properties, health benefits, and overall oil stability. This innovation provides a practical solution for the food industry by improving the biostability and versatility of EVOO. Further research is recommended to investigate various EVOO categories and oils from diverse origins. Full article

Food spoilage is a natural process that influences the quality and safety of food products, negatively affecting their nutritional and organoleptic composition. In these regards, traditional industrial food preservation processes often rely on the use of traditional preservation techniques to extend food shelf life, while ensuring microbiological and chemical stability without compromising the product’s sensory characteristics. However, in recent years, consumers have become increasingly wary of chemical food additives; they often associate their use with potential health risks and negative impact on product appeal. In addition, this is compounded by an increasingly compellent European regulatory framework, as well as efforts in the search of natural and sustainable alternatives for food preservation. In this context, this review explores the potential of natural additives, such as polyphenols, flavonoids, and antioxidants, derived from agro-industrial waste, including fruit peels, vegetable by-products, and seeds. These compounds exhibit strong antioxidant and antimicrobial properties, which not only extend the shelf life of food products but also enhance their safety and quality. Considering vegetable wastes (i.e., pomegranate peels, olive leaves, olive mill wastewater, and grape pomace) as the main by-products from which natural additives can be extracted, this study provides an overview of their efficacy in preventing lipid oxidation and reducing microbial growth, while maintaining sensory properties. This could represent an opportunity both for maintaining food quality and prolonging food shelf life by valorizing by-products to be otherwise disposed of, and also contribute to mitigating the environmental impact associated with the food industry and to optimize food preservation processes. In addition, it highlights the possibility of employing sustainable alternatives to synthetic additives, capable of extending the shelf life of food products while ensuring their safety for human consumption. Full article

Extra virgin olive oil (EVOO) is one of the main daily food items consumed around the world, particularly in the Mediterranean region, and it has unique organoleptic properties. This study aims to determine the best frying conditions of EVOO supplemented with natural exogenous antioxidants enriched in hydroxytyrosol (HTyr) and its derivatives from olive fruit extract (OFE) to conserve its positive sensorial attributes while minimizing its sensorial defects, in particular, rancidity under high thermal processes. In this study, an experienced panel assessed the sensory attributes of nine EVOO varieties, olive oil 0.4° (mixed virgin olive oil (VOO) with refined olive oil (ROO)), Orujo olive oil, and olive oil 1° (EVOO mixed with ROO), compared with two sunflower oil types, performed using a deep-frying (D-F) process with numerous variables, i.e., frying time, frying temperature, and the addition of polyphenols enriched with HTyr. Results showed that most EVOO samples were stable under D-F at 170 °C for 3 h, with added polyphenols (∼650 mg/kg). Moreover, at these best values, the results stated that Arbequina, Picual, Royuella, Hojiblanca, Arbosana, and Manzanilla oils have low rancidity scores with values of 0, 1.7, 1.8, 2.3, 3.1, and 3.7, respectively, and stable/higher positive sensorial attributes, i.e., fruity, bitter, and pungent properties; however, olive oil 1° and olive oil 0.4° have high rancidity and low positive sensorial attributes. Notably, OFE helps maintain bitterness close to control in Picual, Koroneiki, Empeltre, and Arbosana oils. Furthermore, amongst the 19 tested sensory descriptors, only 8 descriptors—namely, fusty/muddy sediment, winey/vinegary/acid/sour, frostbitten olives (wet wood), rancid, fruity (green), fruity (ripe), bitter, and pungent—were successfully developed to allow characterization of the sensory quality of various olive oil categories under D-F. The present research confirmed that OFE may be used to provide stable EVOOs with higher positive sensorial qualities and lower defects and could be used as a natural antioxidant and promising strategy during the D-F process with EVOOs, not only for domestic practices but also at the industrial level. Full article