Olive leaf extracts for shelf life extension of salmon burgers

2018 ◽  
Vol 25 (2) ◽  
pp. 91-100 ◽  
Author(s):  
Ibtihel Khemakhem ◽  
Ana Fuentes ◽  
María Jesús Lerma-García ◽  
Mohamed Ali Ayadi ◽  
Mohamed Bouaziz ◽  
...  

In this work, the effect of the addition of olive leaf extracts on the quality of vacuum-packed salmon burgers stored at 4 ℃ during 16 days has been studied. Olive leaf extract and its hydrolysate were initially characterized and then incorporated to salmon burgers. A shelf life study was conducted in three different batches (control, olive leaf extract, and hydrolyzed olive leaf extract burgers). Among the chemical indices determined, total volatile base nitrogen values were lower in hydrolyzed olive leaf extract and olive leaf extract burgers than in control samples. Lipid oxidation was lower in salmon burger with olive leaf extract. Salmon mince treated with hydrolyzed olive leaf extract showed lower microbial counts during the whole study, which extended the shelf life of the fish product. Therefore, the potential of olive leaf extracts to preserve salmon burgers during cold storage has been demonstrated.

Foods ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 138 ◽  
Author(s):  
Graziana Difonzo ◽  
Giacomo Squeo ◽  
Maria Calasso ◽  
Antonella Pasqualone ◽  
Francesco Caponio

The shelf-life extension implicates the reduction of food waste. Plant polyphenols can have a crucial role in the shelf-life extension of foods. Olive leaf extract (OLE) is rich in phenolic compounds such as oleuropein, which is well-known for its antioxidant properties. Physico-chemical, microbiological and sensory aspects of non-thermally stabilized olive-based pâté fortified with OLE at concentrations of 0.5 (EX0.5) and 1 mg kg−1 (EX1) were investigated. These samples were compared with olive-based pâté fortified with the synthetic antioxidant BHT (butylated hydroxytoluene) and with a control sample (CTR) without antioxidants. No sensory defects were perceived in all samples, even if a more intense typical olive flavour was perceived in samples containing OLE compared to those containing BHT and CTR. This result was confirmed by significantly higher levels of 2-methylbutanal and 3-methylbutanal in samples containing OLE compared to CTR and BHT. Moreover, the main microbial groups registered a significant loss of 0.5–1 logarithmic cycles in samples containing OLE, especially in EX1. The results of the present study indicate the potentiality of using OLE as natural preservatives in non-thermally stabilized olive-based pâté, since some spoilage-related microbial groups were negatively affected by the addition of OLE at the highest concentration.


2018 ◽  
Vol 42 (11) ◽  
pp. e13789 ◽  
Author(s):  
Ali Ragab Shalaby ◽  
Mervat Mohamed Anwar ◽  
Essam Mohamed Sallam

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1446 ◽  
Author(s):  
Giuseppe Natrella ◽  
Graziana Difonzo ◽  
Maria Calasso ◽  
Giuseppe Costantino ◽  
Francesco Caponio ◽  
...  

Undesired volatile organic compounds (VOCs) can negatively affect the flavor of fresh food products; especially those characterized by a mild and delicate aroma. Finding connections between chemical and sensory analyses is a useful way to better understand the arising of off-flavors. A study was conducted on stracciatella; a traditional Italian cream cheese that is emerging on international markets. Samples were prepared by adding two different preservatives (alone or combined): sorbic acid and an olive leaf extract. Their influence on flavor preservation during refrigerated storage was investigated by chemical, microbiological and sensory analyses. A strong change of the VOC profile was ascertained after 8 days in the control cheese and in the sample added with leaf extract alone. The samples containing sorbic acid, alone or in combination with leaf extract, gave the best chemical and sensory results, demonstrating a significant shelf-life extension. In particular, these samples had lower concentrations of undesired metabolites, such as organic acids and volatiles responsible for off-flavor, and received better scores for odor and taste. Ex and Ex-So samples had significantly higher antioxidant activity than Ctr and So throughout the entire storage period, and the color parameter shows no differences among samples taken on the same day. The use of the olive leaf extract, at the concentration tested, seemed to be interesting only in the presence of sorbic acid due to possible synergic effect that mainly acted against Enterobacteriaceae.


Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1268 ◽  
Author(s):  
Annamaria Cedola ◽  
Carmen Palermo ◽  
Diego Centonze ◽  
Matteo Alessandro Del Nobile ◽  
Amalia Conte

Olive leaves are rich in many compounds precious for human health. Due to this property, the current study was aimed to valorize the extract from this by-product in a cereal-based food, very popular all around the world, the “taralli”. To this aim, ultrasound-assisted extraction was applied to dried olive leaves to obtain the extract, used as “taralli” ingredient, instead of white wine. The “taralli” with and without extract was subjected to in vitro digestion to assess the quantity of polyphenolic compounds released in the gastrointestinal tract to become available for absorption. Total content of phenols and flavonoids, as well as the antioxidant capacity, was measured on both cooked and uncooked samples, before and after digestion. In addition, High-Performance Liquid Chromatography with Diode-Array Detection (HPLC-DAD) of the three most abundant polyphenols present in olive leaf extracts, such as oleuropein, hydroxytyrosol, and verbascoside, was carried out at the three stages of the digestion process. The results showed that the substitution of white wine with olive leaf extract increased the total content of polyphenols and flavonoids and the antioxidant capacity. Bio-accessibility of the main phenolic compounds demonstrated that oleuropein resisted slightly after gastric digestion but was almost completely degraded in the intestinal phase, while hydroxytyrosol and verbascoside were not resistant to the digestion process from the gastric phase.


Planta Medica ◽  
2018 ◽  
Vol 84 (12/13) ◽  
pp. 886-894
Author(s):  
Katlego Mmopele ◽  
Sandra Combrinck ◽  
Josias Hamman ◽  
Clarissa Willers ◽  
Weiyang Chen ◽  
...  

AbstractThe African wild olive (Olea europaea subsp. africana) is traditionally used as a hypotensive agent. Herb-drug interactions may result from the concurrent use of herbal medicines and conventional prescription drugs. This aspect was investigated by determining the effect of the extract on the in vitro intestinal epithelial permeation of selected hypotensive drugs using the Caco-2 cell culture model. The phytochemical profiles of leaf extracts of African wild olive from different localities in South Africa were compared, since efficacy is determined by the chemical composition. Extracts were analysed using ultra-performance liquid chromatography. The oleuropein concentration varied considerably from below the detection limit (4.94 µg/mL) to 59.4 mg/g dry weight. Chemometric models constructed from the aligned chromatographic data indicated only quantitative differences between the profiles. The leaf extract was found to increase the permeability of propranolol in the absorptive direction (Papp = 8.93 × 10−6 cm/s) across Caco-2 cell monolayers, but considerably decreased transport in the secretory direction (Papp = 3.68 × 10−6 cm/s). The permeation of diltiazem was enhanced by the extract in both the absorptive (Papp = 7.33 × 10−6 cm/s) as well as in the secretory direction (Papp = 7.16 × 10−6 cm/s), but a decrease in the efflux ratio was observed. The extract therefore caused a net increase in the transport of both drugs in the absorptive direction due to an inhibition effect on their efflux. This suggests a potential increase in the blood levels of these drugs when taken simultaneously with African wild olive leaf extract, indicating potential adverse effects that must be verified in vivo.


Gene Reports ◽  
2020 ◽  
Vol 21 ◽  
pp. 100771 ◽  
Author(s):  
Mozhdeh Fazel Tehrani Moghaddam ◽  
Hossein Jalali ◽  
Abdorreza Mohammadi Nafchi ◽  
Leila Nouri

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