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.

Bioavailable Phenolic Compounds from Olive Pomace Present Anti-Neuroinflammatory Potential on Microglia Cells.

The neuroinflammatory process is considered one of the main characteristics of central nervous system diseases, where a pro-inflammatory response results in oxidative stress through the generation of reactive oxygen and nitrogen species (ROS and RNS). Olive (Olea europaea L.) pomace is a by-product of olive oil production that is rich in phenolic compounds (PCs), known for their antioxidant and anti-inflammatory properties. This work looked at the antioxidant and anti-neuroinflammatory effects of the bioavailable PC from olive pomace in cell-free models and microglia cells. The bioavailable PC of olive pomace was obtained through the process of in vitro gastrointestinal digestion of fractionated olive pomace (OPF, particles size < 2 mm) and micronized olive pomace (OPM, particles size < 20 µm). The profile of the PC that is present in the bioavailable fraction as well as its in vitro antioxidant capacity were determined. The anti-neuroinflammatory capacity of the bioavailable PC from olive pomace (0.03-3 mg L-1) was evaluated in BV-2 cells activated by lipopolysaccharide (LPS) for 24 h. The total bioavailable PC concentration and antioxidant activity against peroxyl radical were higher in the OPM than those observed in the OPF sample. The activation of BV-2 cells by LPS resulted in increased levels of ROS and nitric oxide (NO). The bioavailable PCs from both OPF and OPM, at their lowest concentrations, were able to reduce the ROS generation in activated BV-2 cells. In contrast, the highest PC concentration of OPF and OPM was able to reduce the NO levels in activated microglial cells. Our results demonstrate that bioavailable PCs from olive pomace can act as anti-neuroinflammatory agents in vitro, independent of particle size. Moreover, studies approaching ways to increase the bioavailability of PCs from olive pomace, as well as any possible toxic effects, are needed before a final statement on its nutritional use is made.

Effect of micronization on olive pomace biotransformation in the static model of colonic fermentation.

The effect of granulometric fractionation and micronization of olive pomace (OP) on the biotransformation of phenolic compounds by intestinal microbiota was investigated in vitro. Three types of powdered OP samples were incubated with human feces to simulate colonic fermentation, after a sequential static digestion: non-fractionated OP (NF), granulometrically fractionated OP (GF) and granulometrically fractionated and micronized OP (GFM). GF and GFM favored the release of hydroxytyrosol, oleuropein aglycone, apigenin and phenolic acid metabolites in the first hours of colonic fermentation compared to NF (up to 41-fold higher). GFM caused higher release of hydroxytyrosol than GF. GFM was the only sample to release tyrosol and sustained tyrosol levels up to 24 h of fermentation. Micronization associated with granulometric fractionation was more efficient than granulometric fractionation alone to increase the release of phenolic compounds from the OP matrix during simulated colonic fermentation and can be further studied for nutraceutical purposes.

Grain Germination Changes the Profile of Phenolic Compounds and Benzoxazinoids in Wheat: A Study on Hard and Soft Cultivars.

Pre-harvest sprouting is a frequent problem for wheat culture that can be simulated by laboratory-based germination. Despite reducing baking properties, wheat sprouting has been shown to increase the bioavailability of some nutrients. It was investigated whether wheat cultivars bearing distinct grain texture characteristics (BRS Guaraim, soft vs. BRS Marcante, hard texture) would have different behavior in terms of the changes in phytochemical compounds during germination. Using LC-Q-TOF-MS, higher contents of benzoxazinoids and flavonoids were found in the hard cultivar than in the soft one. Free phytochemicals, mainly benzoxazinoids, increased during germination in both cultivars. Before germination, soft and hard cultivars had a similar profile of matrix-bound phytochemicals, but during germination, these compounds have been shown to decrease only in the hard-texture cultivar, due to decreased levels of phenolic acids (trans-ferulic acid) and flavonoids (apigenin) that were bound to the cell wall through ester-type bonds. These findings confirm the hypothesis that hard and soft wheat cultivars have distinct behavior during germination concerning the changes in phytochemical compounds, namely the matrix-bound compounds. In addition, germination has been shown to remarkably increase the content of benzoxazinoids and the antioxidant capacity, which could bring a health-beneficial appeal for pre-harvested sprouted grains.

Natural deep eutectic solvent (NADES): A strategy to improve the bioavailability of blueberry phenolic compounds in a ready-to-use extract.

This study investigated whether a ready-to-use extract obtained using a natural deep eutectic solvent (NADES) affects the pharmacokinetic profile of blueberry phenolic compounds compared to organic solvent (SORG)-extracted compounds. SORG extract was administered as an aqueous solution after solvent removal. Wistar rats received a single dose of crude extract of blueberry obtained using NADES (CE-NADES) or SORG (CE-SORG), followed by LC-DAD-MS/MS analysis of blood and cecal feces. Non-compartmental pharmacokinetic analysis revealed that CE-NADES increased the bioavailability of anthocyanins by 140% compared to CE-SORG. CE-NADES increased the stability of phenolic compounds during in vitro digestion by delaying gastric chyme neutralization. These results suggest that besides being an eco-friendly solvent for the extraction of phytochemicals, choline chloride:glycerol:citric acid-based NADES can be used as a ready-to-use vehicle for increasing oral absorption of bioactive compounds such as anthocyanins.

Extrato de tomate: características físico-químicas e microscópicas

O tomate está entre os frutos mais consumidos mundialmente, devido à diversidade de produtos derivados, sendo os principais suco, molho, ketchup e extrato de tomate. Este trabalho teve como objetivo analisar as características físico-químicas e microscópicas de extratos de tomate. Sete marcas de extratos de tomate, totalizando 21 amostras, foram analisadas quanto aos teores de sólidos solúveis totais (SST), pH, acidez total titulável (ATT), umidade, cinzas, cloreto de sódio, coloração e determinação de matérias estranhas. Foram verificadas diferenças significativas entre as amostras para os SST, porém, todas as amostras apresentaram teores superiores a 6%, estando de acordo com a legislação. Os demais parâmetros físico-químicos, mostram-se semelhantes aos encontrados na literatura. Na análise microscópica, somente uma amostra não estava conforme a legislação vigente, apresentando fragmentos de insetos acima do limite de tolerância.

Tomato is among the most consumed fruits worldwide, due to diversity of products produced, including juice, sauce, ketchup and tomato extract. The work has as objective analyze the physico-chemical characteristics and microscopic of tomato extracts. Seven brands of tomato extracts, totaling 21 samples, were analyzed as to the levels of total soluble solids (TSS), pH, titratable total acidity (TTA), moisture, ashes, sodium chloride, coloring and determination of foreign material. Significant differences were found between samples for TSS, however, all samples presented levels higher than 6%, being in accordance with the legislation. The other physicalchemical parameters are similar to those found in the literature. In microscopic analysis, only one brand was not compliant with the current legislation, presenting insect fragments above the tolerance limit.

Extrato de tomate: características físico-químicas e microscópicas

O tomate está entre os frutos mais consumidos mundialmente, devido à diversidade de produtos derivados, sendo os principais suco, molho, ketchup e extrato de tomate. Este trabalho teve como objetivo analisar as características físico-químicas e microscópicas de extratos de tomate. Sete marcas de extratos de tomate, totalizando 21 amostras, foram analisadas quanto aos teores de sólidos solúveis totais (SST), pH, acidez total titulável (ATT), umidade, cinzas, cloreto de sódio, coloração e determinação de matérias estranhas. Foram verificadas diferenças significativas entre as amostras para os SST, porém, todas as amostras apresentaram teores superiores a 6%, estando de acordo com a legislação. Os demais parâmetros físico-químicos, mostram-se semelhantes aos encontrados na literatura. Na análise microscópica, somente uma amostra não estava conforme a legislação vigente, apresentando fragmentos de insetos acima do limite de tolerância

Tomato is among the most consumed fruits worldwide, due to diversity of products produced, including juice, sauce, ketchup and tomato extract. The work has as objective analyze the physico-chemical characteristics and microscopic of tomato extracts. Seven brands of tomato extracts, totaling 21 samples, were analyzed as to the levels of total soluble solids (TSS), pH, titratable total acidity (TTA), moisture, ashes, sodium chloride, coloring and determination of foreign material. Significant differences were found between samples for TSS, however, all samples presented levels higher than 6%, being in accordance with the legislation. The other physicalchemical parameters are similar to those found in the literature. In microscopic analysis, only one brand was not compliant with the current legislation, presenting insect fragments above the tolerance limit