title: Utilising Olive Leaves to Enrich Olive Oil  with Oleuropein Aglycone

authors: te Bogt, Jade

subjects: olive oil

abstract: Olive oil (OO) is an excellent source of minor bioactive compounds, such as oleuropein aglycone, which is gaining increasing attention due to its biological properties and benefits on human health. The European Food Safety Authority (EFSA) have approved a health claim for OO if it contains 250 mg/kg of these desired bioactive compounds. However, the concentrations of bioactive compounds can vary between batches of OO and may contain bioactive compounds that are below the threshold which provides health benefits. Enrichment of OO is commonly employed to achieve a higher concentration of these bioactive compounds. Often a waste product such as olive leaves is used because it contains a significant amount of the oleuropein aglycone precursor, oleuropein glycoside (8-14% dry weight).  
The present research aimed to analyse commercial extra virgin olive oils (EVOOs) in the New Zealand market, explore the effect of olive leaf drying on the composition of oleuropein in olive leaf tea (OLT) and the stability of OLT stored at different temperatures (−20, RT, 40 °C, 189 days). Lastly, an investigation was carried out to determine whether the oleuropein in OLT could be hydrolysed to oleuropein aglycone via an exogenous source of β-glucosidase (almond flour/meal) so that the resulting aglycone could be transferred into a low content OO producing an enriched marketable product with health benefits.  
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated and was used to analyse target analytes in New Zealand commercial EVOOs (n = 9). There was a large variation in the concentration of target analytes (oleuropein, ligstroside, oleuropein aglycone, oleocanthal, oleacein, hydroxytyrosol, tyrosol and elenolic acid) and none of the oils analysed met the health claim (250 mg/kg). The content of oleuropein in OLT increased under different leaf drying conditions in the order fresh<RT<70 °C while other target analytes tended to increase with drying at RT. The period leaves were left to dry was also deemed a crucial factor in the concentrations obtained. A stability experiment of OLT  ii determined that the majority of target analytes were stable at −20 °C and RT, whereas precursors such as oleuropein and ligstroside degraded at 40 °C.  
Almond flour/meal proved to be an effective source of exogenous β-glucosidase to hydrolyse oleuropein in OLT; however, the mass transfer of aglycone into the oil was complex. Changing the source of enzyme to almond milk resulted in an aglycone concentration of 6 mg/kg in the oil but this also resulted in oleuropein aglycone to be quantified in the aqueous portion of samples (the highest being 613 mg/kg). The presence of a hydrophobic compound in the aqueous portion of samples was unexpected. It was thought this result may be caused by solubilisation through thermodynamically stable micelle formation within the emulsion formed during enrichment experiments. Salting out the reaction resulted in the highest amount of aglycone (30 mg/kg) as this process likely disrupted micelle formation.  
Since commercial EVOOs vary in concentration of analytes such as oleuropein aglycone, enriching an OO is desirable. OLT can be used as an effective source of oleuropein which can be hydrolysed via β-glucosidase present in almond flour/meal and milk. However, the mass transfer of the respective aglycone into olive oil to achieve an enriched product with a concentration at or above the health claim (250 mg/kg) was complex.

text: Utilising Olive Leaves to Enrich Olive Oil  with Oleuropein Aglycone Olive oil (OO) is an excellent source of minor bioactive compounds, such as oleuropein aglycone, which is gaining increasing attention due to its biological properties and benefits on human health. The European Food Safety Authority (EFSA) have approved a health claim for OO if it contains 250 mg/kg of these desired bioactive compounds. However, the concentrations of bioactive compounds can vary between batches of OO and may contain bioactive compounds that are below the threshold which provides health benefits. Enrichment of OO is commonly employed to achieve a higher concentration of these bioactive compounds. Often a waste product such as olive leaves is used because it contains a significant amount of the oleuropein aglycone precursor, oleuropein glycoside (8-14% dry weight).  
The present research aimed to analyse commercial extra virgin olive oils (EVOOs) in the New Zealand market, explore the effect of olive leaf drying on the composition of oleuropein in olive leaf tea (OLT) and the stability of OLT stored at different temperatures (−20, RT, 40 °C, 189 days). Lastly, an investigation was carried out to determine whether the oleuropein in OLT could be hydrolysed to oleuropein aglycone via an exogenous source of β-glucosidase (almond flour/meal) so that the resulting aglycone could be transferred into a low content OO producing an enriched marketable product with health benefits.  
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated and was used to analyse target analytes in New Zealand commercial EVOOs (n = 9). There was a large variation in the concentration of target analytes (oleuropein, ligstroside, oleuropein aglycone, oleocanthal, oleacein, hydroxytyrosol, tyrosol and elenolic acid) and none of the oils analysed met the health claim (250 mg/kg). The content of oleuropein in OLT increased under different leaf drying conditions in the order fresh<RT<70 °C while other target analytes tended to increase with drying at RT. The period leaves were left to dry was also deemed a crucial factor in the concentrations obtained. A stability experiment of OLT  ii determined that the majority of target analytes were stable at −20 °C and RT, whereas precursors such as oleuropein and ligstroside degraded at 40 °C.  
Almond flour/meal proved to be an effective source of exogenous β-glucosidase to hydrolyse oleuropein in OLT; however, the mass transfer of aglycone into the oil was complex. Changing the source of enzyme to almond milk resulted in an aglycone concentration of 6 mg/kg in the oil but this also resulted in oleuropein aglycone to be quantified in the aqueous portion of samples (the highest being 613 mg/kg). The presence of a hydrophobic compound in the aqueous portion of samples was unexpected. It was thought this result may be caused by solubilisation through thermodynamically stable micelle formation within the emulsion formed during enrichment experiments. Salting out the reaction resulted in the highest amount of aglycone (30 mg/kg) as this process likely disrupted micelle formation.  
Since commercial EVOOs vary in concentration of analytes such as oleuropein aglycone, enriching an OO is desirable. OLT can be used as an effective source of oleuropein which can be hydrolysed via β-glucosidase present in almond flour/meal and milk. However, the mass transfer of the respective aglycone into olive oil to achieve an enriched product with a concentration at or above the health claim (250 mg/kg) was complex.

year: 2023

title: Sustaining e-commerce profitability: A hybrid quantitative investigation into critical success factors (CSFs)

authors: Kord, Hamidreza

subjects: e-commerce

abstract: In the contemporary digital landscape, e-commerce has rapidly evolved, reshaping consumer behaviour and the retail industry. This study explores the dynamic factors affecting customer satisfaction and profitability in e-commerce. Utilising a comprehensive methodological framework that includes fuzzy Delphi, fuzzy BWM, C-means clustering, and fuzzy COPRAS methods, the research identifies and prioritises critical success factors influencing online consumer behaviour. An analysis of 602 customer records classifies purchasing behaviours and demographic characteristics into distinct clusters. Key findings underscore the significance of customer reviews, recommendation systems, shopping satisfaction, and personalised shopping experiences in driving e-commerce success. Methodologically, the study demonstrates the effectiveness of advanced analytical techniques in managing uncertainty and complexity in e-commerce data. Despite its contributions, the research acknowledges limitations, including the cross-sectional nature of the data, sample size constraints, and the need for broader generalisability. Future research directions include integrating emerging technologies, conducting longitudinal studies, and developing cross-channel strategies to enhance customer engagement and profitability.

text: Sustaining e-commerce profitability: A hybrid quantitative investigation into critical success factors (CSFs) In the contemporary digital landscape, e-commerce has rapidly evolved, reshaping consumer behaviour and the retail industry. This study explores the dynamic factors affecting customer satisfaction and profitability in e-commerce. Utilising a comprehensive methodological framework that includes fuzzy Delphi, fuzzy BWM, C-means clustering, and fuzzy COPRAS methods, the research identifies and prioritises critical success factors influencing online consumer behaviour. An analysis of 602 customer records classifies purchasing behaviours and demographic characteristics into distinct clusters. Key findings underscore the significance of customer reviews, recommendation systems, shopping satisfaction, and personalised shopping experiences in driving e-commerce success. Methodologically, the study demonstrates the effectiveness of advanced analytical techniques in managing uncertainty and complexity in e-commerce data. Despite its contributions, the research acknowledges limitations, including the cross-sectional nature of the data, sample size constraints, and the need for broader generalisability. Future research directions include integrating emerging technologies, conducting longitudinal studies, and developing cross-channel strategies to enhance customer engagement and profitability.

year: 2024-06-13

title: Equity, equality, and biculturalism in the restructuring of New Zealand schools: A life-history approach

authors: Middleton, Sue

subjects: New Zealand

abstract: Interview data from the initial phase of "Monitoring Today's Schools," a research project to monitor the impact of New Zealand's educational restructuring, are examined.

text: Equity, equality, and biculturalism in the restructuring of New Zealand schools: A life-history approach Interview data from the initial phase of "Monitoring Today's Schools," a research project to monitor the impact of New Zealand's educational restructuring, are examined.

year: 1992