Changes in secoiridoids content and chemical characteristics of cultivated and wild Algerian olive oil, in term of fruit maturation

A Review of Recent Progresses on Olive Oil Chemical Profiling, Extraction Technology, Shelf-life, and Quality Control

Olive oil (OO) is widely recognized as a main component in the Mediterranean diet owing to its unique chemical composition and associated health-promoting properties. This review aimed at providing readers with recent results on OO physicochemical profiling, extraction technology, and quality parameters specified by regulations to ensure authentic products for consumers. Recent research progress on OO adulteration were outlined through a bibliometric analysis mapping using Vosviewer software. As revealed by bibliometric analysis, richness in terms of fatty acids, pigments, polar phenolic compounds, tocopherols, squalene, sterols, and triterpenic compounds justify OO health-promoting properties and increasing demand on its global consumption. OO storage is a critical post-processing operation that must be optimized to avoid oxidation. Owing to its great commercial value on markets, OO is a target to adulteration with other vegetable oils. In this context, different chemometric tools were developed to deal with this problem. To conclude, increasing demand and consumption of OO on the global market is justified by its unique composition. Challenges such as oxidation and adulteration stand out as the main issues affecting the OO market.

Wild and cultivated olive trees: Nutraceutical insights of extra virgin olive oils in cardiovascular and ocular diseases

Extra virgin olive oil (EVOO) from Olea europaea (cultivated olive tree) and the oil obtained from the wild olive variety or acebuche (ACE oil from Olea oleaster) contain an extraordinary number of bioactive molecules. These include oleic acid, sterols, tocopherols, triterpene compounds, and polyphenols. Both oils are known for their healthy properties and are considered to be a nutraceutical tool against cardiovascular diseases, including arterial hypertension, preeclampsia, and ocular diseases such as glaucoma or diabetic retinopathy. The benefits of EVOO and ACE oil stem from their anti-inflammatory, antioxidant, and anti-cancer properties. They also have potential as prebiotic compounds. In this update, we synthesise and illustrate the various characteristics and beneficial effects of olive oils from different varieties of olive trees, with special emphasis on Olea oleaster, also known as Olea europaea, L. var. sylvestris.

Maturity impact on physicochemical composition and polyphenol properties of extra virgin olive oils obtained from Manzanilla, Arbequina, and Koroneiki varieties in Iran

This study investigated the physicochemical properties and polyphenol composition of extra virgin olive oils (EVOOs) extracted from three olive cultivars. The investigated cultivars were Arbequina, Koroneiki, and Manzanilla, grown in Olive Research Station in Rudbar county, Gilan province, Iran, at three ripening stages. Several parameters were analyzed, including peroxide and acidity values, unsaponifiable matter, oxidative stability, total aliphatic alcohols, fatty acids (FAs), sterols, and triacylglycerol composition. The results showed that as maturity increased, parameters such as oil content, acidity value, and iodine value, rise, while parameters including peroxide value, oxidative stability, aliphatic alcohols, and unsaponifiable matter decreased (p < .05). The saponification value was slightly reduced in the developing ripening process (p > .05). The MUFA/PUFA ratio and total sterol content declined during the olive ripening stages (p < .05). The triterpenes decreased in Arbequina and Koroneiki cultivars but increased in Manzanilla cultivar during the maturity stages. According to the data, oleuropein decreased while oleuropein aglycone, oxidized aldehyde, and hydroxylic form of oleuropein increased for all EVOOs during maturation. Apigenin, quercetin, ligstroside aglycone, aldehyde and hydroxylic form, ferulic acid, caffeic acid, and catechin decreased during the ripening of fruits (p < .05). The main triglycerides were triolein (OOO), palmitodiolein (POO), dioleolinolein (OOL), and palmitooleolinolein (PLO) in all EVOOs. In addition, the olive cultivar and harvesting date influence the physicochemical properties and polyphenol composition of EVOOs extracted from olive varieties grown in one region. In conclusion, the results can present helpful information to determine the optimum maturity stage for the investigated olive cultivars.

An olive-derived elenolic acid stimulates hormone release from L-cells and exerts potent beneficial metabolic effects in obese diabetic mice

Insulin resistance and progressive decline in functional β-cell mass are two key factors for developing type 2 diabetes (T2D), which is largely driven by overweight and obesity, a significant obstacle for effective metabolic control in many patients with T2D. Thus, agents that simultaneously ameliorate obesity and act on multiple pathophysiological components could be more effective for treating T2D. Here, we report that elenolic acid (EA), a phytochemical, is such a dual-action agent. we show that EA dose-dependently stimulates GLP-1 secretion in mouse clonal L-cells and isolated mouse ileum crypts. In addition, EA induces L-cells to secrete peptide YY (PYY). EA induces a rapid increase in intracellular [Ca²⁺]_i and the production of inositol trisphosphate in L-cells, indicating that EA activates phospholipase C (PLC)-mediated signaling. Consistently, inhibition of (PLC) or Gα_q ablates EA-stimulated increase of [Ca²⁺]_i and GLP-1 secretion. In vivo, a single dose of EA acutely stimulates GLP-1 and PYY secretion in mice, accompanied with an improved glucose tolerance and insulin levels. Oral administration of EA at a dose of 50 mg/kg/day for 2 weeks normalized the fasting blood glucose and restored glucose tolerance in high-fat diet-induced obese (DIO) mice to levels that were comparable to chow-fed mice. In addition, EA suppresses appetite, reduces food intake, promotes weight loss, and reverses perturbated metabolic variables in obese mice. These results suggest that EA could be a dual-action agent as an alternative or adjuvant treatment for both T2D and obesity.

One drop only. Easy and rapid Raman evaluation of β-carotene in olive oil and its relevance as an index of olive fly attack

This paper presents, for the first time, a method for the rapid quantification of β-carotene in olive oil by Raman spectroscopy. Using a 532 nm Raman laser source, our procedure requires only one drop (100 µL) of oil, for β-carotene content to be determined. Results show that β-carotene content is associated with the lutein/β-carotene ratio, a parameter whose value describes how healthy the olives were before processing, specifically whether an olive fly attack occurred. Since olive fly attacks are not always visible to the oil producers, this method gives them the means to control the validity of the prevention strategies they adopted.