Chemical Composition and Antimicrobial Activity of a New Olive Pomace Functional Ingredient

Abstract

Olive pomace, an olive oil processing byproduct, can be upcycled and meet the current demand for natural and sustainable food ingredients. In this work, a patented process was used to obtain a functional ingredient from different olive pomaces. The nutritional, chemical and antioxidant profiles, as well as the antimicrobial activity against S. aureus, E. coli and C. albicans, were investigated for the first time. The amount of phenolics ranged between 3.1 and 3.8 g gallic acid eq./100 g in all samples and flavonoids between 2.0 and 3.2 g catechin eq/100 g. No significant differences were found regarding the antioxidant activity. The total fat varied between 5 and 11%, α-tocopherol being the major vitamer and oleic acid the main fatty acid. The protein and ash contents were 1–4% and 10–17%, respectively. The functional ingredient with a higher hydroxytyrosol content (220 mg/100 g) also presented the best minimal inhibitory concentration against the tested bacteria. No activity against C. albicans was verified. This new functional ingredient presents the potential to be used as a natural preservative or as a nutritional profile enhancer. Moreover, it can be an advantageous ingredient in food products, since it comprises specific lipid and hydrophilic bioactive compounds usually not present in other plant extracts.

Unveiling the Antioxidant Therapeutic Functionality of Sustainable Olive Pomace Active Ingredients

“…These results are in agreement with the previous statement that ethanol has an important role in the recovery of biomolecules with higher antioxidant capacities [36]. Several authors reported that OP-derived extracts have an interesting antioxidant capacity that may be related to the content of phenolic compounds [34,37,38]. For example, Ribeiro et al [34] evaluated the antioxidant capacity of OP extracts using three different methods (DPPH, ABTS, and ORAC), and their results showed high antioxidant activity for the methanolic extracts of OP.…”

“…Ribeiro et al [34] reported TPC values above 20 mg GAE/g OP using methanol as a solvent. On the other hand, Nunes et al [37] quantified about 30 mg GAE/g OP using water as the extraction medium.…”

“…For example, Ribeiro et al [34] evaluated the antioxidant capacity of OP extracts using three different methods (DPPH, ABTS, and ORAC), and their results showed high antioxidant activity for the methanolic extracts of OP. Nunes et al [37] report a relationship of antioxidant activity (DPPH, ABTS, and FRAP) with HT content for water-soluble extractives of OP by-product of several olive varieties from the northeast region (Behind-the-hills) and south (Alentejo) of Portugal.…”

Effects of Functional Coatings Containing Chitosan, Orange Peel and Olive Cake Extracts on the Quality Attributes of Cucumber during Cold Storage

“…TVC ( Figure 1 a) and yeast and mold counts ( Figure 1 b) were the highest in the uncoated cucumber samples followed by those coated with 2% chitosan only, whereas the lowest counts were seen in cucumber coated with functional materials (2% OCE and 2% OPE), suggesting the protective effects of these materials against spoilage microbes in cucumber samples. The reduction in TVC and mold and yeast counts in the coated cucumber with chitosan containing OCE and OPE is likely due to the presence of the phytochemicals with high antimicrobial activity of olive cake and orange peel extract as reported previously [ 22 , 30 ]. In addition, the coating material formed a protective layer on the surface of the cucumber samples, thereby reducing the microbial contamination and growth [ 9 ].…”

Teucrium polium (L.): Phytochemical Screening and Biological Activities at Different Phenological Stages

“…The Gram-negative bacteria have rigid cell walls, the main component of which are lipopolysaccharides, making these bacteria more resistant to different antibacterial agents. In contrast, the Gram-positive bacteria cell walls are homogeneous and do not contain phospholipids [ 73 ]. It is reported that the plant extracts are hydrophobic in nature, while the Gram-negative bacteria outer membranes have some hydrophilic porins; hence, the diffusion of the plant extract compounds into the Gram-negative bacteria is hindered [ 74 ].…”