Evidence of oleuropein degradation by olive leaf protein extract

Leonardis, Antonella De; Macciola, Vincenzo; Cuomo, Francesca

doi:10.1016/j.foodchem.2014.12.016

Cited by 31 publications

(31 citation statements)

References 40 publications

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“…Convection drying of OL at 37 °C led to the lowest content of total phenols (31.25 g kg −1 DM), while the highest values were obtained with lyophilization (60.46 g kg −1 DM) and microwave drying at 100 W (61.90 g kg −1 DM). The low level of total phenols in OL dried at 37 °C could be attributed to the hydrolysis of some phenols by intrinsic enzymes such as polyphenol oxidase and β ‐glucosidase, which have optimal degrading activity around 37 °C. The preservation of phenolic levels under other drying conditions might be due to inactivation or early denaturation of phenolic‐degrading enzymes …”

Section: Resultsmentioning

confidence: 99%

Valorization of functional properties of extract and powder of olive leaves in raw and cooked minced beef meat

2017

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Section: Resultsmentioning

confidence: 99%

Valorization of functional properties of extract and powder of olive leaves in raw and cooked minced beef meat

2017

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“…The transformation of oleuropein is dependent on the type of glycosylation enzyme acting (β-glucosidase, hemicellulase, tannase, neutral protease, cellulase, glucoamylase, papain, alkaline protease, amylase, β-glucanase) and this will result in varied concentrations and ratios of HT, oleuropein aglycone, elonolic acid and total phenolics [86,87]. The combination of polyphenols may improve the OLE biostability, insuring polyphenols are still present in the olive leaf extract when consumed by humans but also improving the polyphenols ability to reach different areas of the body intact.…”

Section: Bioavailability Of Olive Leaf Polyphenolsmentioning

confidence: 99%

“…The combination of polyphenols may improve the OLE biostability, insuring polyphenols are still present in the olive leaf extract when consumed by humans but also improving the polyphenols ability to reach different areas of the body intact. For example oxidoreductase enzymes reduce the abundance of oleuropein in OLE, but the presence of HT is able to inhibit their action [86]. …”

Section: Bioavailability Of Olive Leaf Polyphenolsmentioning

confidence: 99%

Evidence to Support the Anti-Cancer Effect of Olive Leaf Extract and Future Directions

et al. 2016

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The traditional Mediterranean diet (MD) is associated with long life and lower prevalence of cardiovascular disease and cancers. The main components of this diet include high intake of fruit, vegetables, red wine, extra virgin olive oil (EVOO) and fish, low intake of dairy and red meat. Olive oil has gained support as a key effector of health benefits and there is evidence that this relates to the polyphenol content. Olive leaf extract (OLE) contains a higher quantity and variety of polyphenols than those found in EVOO. There are also important structural differences between polyphenols from olive leaf and those from olive fruit that may improve the capacity of OLE to enhance health outcomes. Olive polyphenols have been claimed to play an important protective role in cancer and other inflammation-related diseases. Both inflammatory and cancer cell models have shown that olive leaf polyphenols are anti-inflammatory and protect against DNA damage initiated by free radicals. The various bioactive properties of olive leaf polyphenols are a plausible explanation for the inhibition of progression and development of cancers. The pathways and signaling cascades manipulated include the NF-κB inflammatory response and the oxidative stress response, but the effects of these bioactive components may also result from their action as a phytoestrogen. Due to the similar structure of the olive polyphenols to oestrogens, these have been hypothesized to interact with oestrogen receptors, thereby reducing the prevalence and progression of hormone related cancers. Evidence for the protective effect of olive polyphenols for cancer in humans remains anecdotal and clinical trials are required to substantiate these claims idea. This review aims to amalgamate the current literature regarding bioavailability and mechanisms involved in the potential anti-cancer action of olive leaf polyphenols.

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“…BG is a key enzyme that has also been used for OLE conversion to HT by facilitating the release of HT and glucose from both verbascoside and HT glucoside and also by catalyzing hydrolysis of carbohydrates and cleavage of bonds present in glycosides . Several researchers have studied HT production using BG hydrolysis from olive mill waste , as well as from olive leaves . Meanwhile, hemicellulase has been used to hydrolyze OLE to HT .…”

Section: Introductionmentioning

confidence: 99%

Efficient bioconversion of oleuropein from olive leaf extract to antioxidant hydroxytyrosol by enzymatic hydrolysis and high‐temperature degradation

Liu

Yong

2018

Biotech and App Biochem

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Hydroxytyrosol (HT), a powerful antioxidant, clears free radicals and exhibits many biological activities. Because contents of HT are low in natural sources, bioconversion of oleuropein (OLE) to HT is of increasing interest. A biotechnological process was investigated to produce HT from OLE presented in olive leaf extract. Enzymatic hydrolysis using two cellulases with high β-glucosidase activity, Novozymes CTec2 and commercial cellulase KDN (Qingdao, People's Republic of China) was carried out at 50 °C for 12 H followed by raising the temperature to 90 °C for chemical hydrolysis. After 48 H of hydrolysis, an OLE degradation rate of 100% and a HT yield of 86-88% were achieved. These cellulases degrade OLE and release a glucose molecule. Chemical hydrolysis at a high temperature promotes the cleavage of ester bond and the formation of HT. This process has a promising alternative for production of HT comparing with acid hydrolysis which not only causes significant pollution to the environment but also makes difficult to the subsequent separation.

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Evidence of oleuropein degradation by olive leaf protein extract

Cited by 31 publications

References 40 publications

Valorization of functional properties of extract and powder of olive leaves in raw and cooked minced beef meat

Valorization of functional properties of extract and powder of olive leaves in raw and cooked minced beef meat

Evidence to Support the Anti-Cancer Effect of Olive Leaf Extract and Future Directions

Efficient bioconversion of oleuropein from olive leaf extract to antioxidant hydroxytyrosol by enzymatic hydrolysis and high‐temperature degradation

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