Algeria has several genetic resources on olive trees, mainly made up of small indigenous cultivars, and a very important wild heritage. Twenty olive samples including eight cultivars and twelve wild trees from the province of Bejaia (Algeria) are characterized, by combining molecular data (13 SSRs), fruit and pit morphological traits, fatty acids composition, and phenolic compounds of the extra virgin olive oils (EVOOs). The genetic results based on PCoA, UPGMA, and AMOVA analyses demonstrate that olive cultivars and wild trees are mixed, suggesting kinship relationships between cultivated and wild olive trees and even cases of synonymy between some cultivars. PCA analysis on morphological traits shows a good separation of the two olive botanical varieties, the wild olive trees producing smaller fruits than those of the cultivated ones. Significant differences are also found in terms of fatty acids and phenol compounds composition of the EVOOs. Wild olive oils show the highest contents on phenolic compounds, mainly oleocanthal, as well as a considerable richness on oleic acid. The comparison of pairwise distances between olive trees obtained by genetic, morphological, fatty acids and phenolic compounds contents data using Mantel's test indicates a significant correlation among morphological characteristics, DNA polymorphism, and phenolic compounds. The results obtained in the present work contribute to reveal the diversity existing in the cultivated and wild olive trees of the region of Bejaia, shedding some light on the importance of Algerian olives germplasm. Practical Applications: Cultivated and wild olive diversity are assessed by genetic, morphological, fatty acids and phenolic composition. SSR marker analysis demonstrates the presence of a high genetic variation between the analyzed samples. A significant correlation of morphological characteristics with DNA polymorphism and phenolic compounds is found. A significant diversity in the wild and cultivated olive trees is observed. Kinship relationships between wild and cultivated Algerian olive trees are demonstrated using SSR markers, while the morphological parameters allow a good distinction between the two taxa. Significant differences are found for fatty acids and phenol compounds composition for the EVOOs; the wild olive oils present an interesting composition compared to the cultivated form.

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The aim of this work was to set up a phenomenological model to predict the stability of extra virgin olive oil based on combined stability/instability indices. A screening of stability/instability indices was carried out by multivariate statistical analyses on company data for virgin olive oil. Screened indices were acidity, oleic acid content and bitter taste. The ability of these indices to predict stability was checked by measuring the following degradation parameters on 11 oil samples of different compositions planned by a fractional factorial design (FFD): peroxide value, UV spectroscopic indices, minor polar component content, oxidative status of fatty acids, antioxidant activity and sensory descriptors of aroma, taste and flavour. Experimental data were processed by multivariate statistical analyses. A combination of acidity, oleic acid content and bitter taste values was significantly able to predict oil stability expressed by the peroxide value, the K 232 UV index and the oxidative status of fatty acids.

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Cross-flow microfiltration (MF) and ultrafiltration (UF) with different commercial membranes were applied to virgin olive oil (VOO) in order to remove some compounds that are responsible for oil unpleasant flavor without altering the oil composition. Experimental tests were carried out using a Spanish VOO from Andalusia, which had the typical eucalyptus aroma. Several classical analytical parameters (acidity, peroxide number, UV absorbance) were determined. Moreover, the contents of total chlorophyll and minor polar compounds were detected. The effect of filtration on oil aroma was evaluated by detecting carbonyl compounds and by a panel of trained tasters. The UF Carbosep M1 membrane was the most suitable for softening the oil organoleptic features. Carbosep UF M1 and MF M14 membranes also induced a reduction of the content of total chlorophyll, which certainly slowed down the oil oxidation processes. It should be considered, however, that the observed decrease in the content of phenolic compounds with Carbosep M1 might have an adverse affect on the oil's stability to oxidation, but the observed decrease in total chlorophyll content should oppose it.

Producers have to guarantee the extra virgin olive oil (EVOO) quality characteristics reported in the Regulation (CEE) 2568/91 throughout the product shelf-life (SL). Unfortunately, due to the development of oxidative reactions, some quality indices change during storage leading to a progressive deterioration of EVOO quality. To avoid the risk of product downgrading in the virgin oil category, the development of effective shelf-life prediction models is extremely important for the olive oil industry. In this research, the accelerated shelf-life testing (ASLT) protocol was applied to evaluate the temperature dependence of selected oxidation indexes as well as to develop a shelf-life predictive model. The evolution of conventional (peroxide value, K232, K270, polyphenols, tocopherols and hexanal) and unconventional parameters (conjugated trienes and pyropheophytin a) was monitored in bottled EVOO stored in the dark at increasing temperature (25, 40, 50 and 60 °C). Accordingly, for well-packed products with reduced oxygen in headspace, the best shelf-life index allowing the ability to predict EVOO SL turned out to be K270. In addition, pyropheophytin a (%) has been shown to be more sensitive to temperature changes than the secondary oxidation indices, thus suggesting its use as a freshness indicator for storage temperatures higher than 25 °C.

SUMMARY:The phenolic compositions, antioxidant and antimicrobial activities against six bacteria of phenolic extracts of olive oil varieties from eleven Algerian varieties were investigated. The antioxidant activity was assessed by determining the scavenging effect on the DPPH and ABTS .+ radicals. The antimicrobial activity was measured as a zone of inhibition and minimum inhibitory concentration (MIC) on human harmful and foodborne pathogens. The results show that total phenols was significantly (p< 0.05) correlated with DPPH (r = 0.72) and ABTS .+ radicals (r = 0.76). Among the bacteria tested, S. aureus and to a lesser extent B. subtilis showed the highest sensitivity; the MIC varied from 0.6 to 1.6 mg·mL -1 and 1.2 to 1.8 mg·mL -1 , respectively. The results reveal that Algerian olive oils may constitute a good source of antioxidant and antimicrobial agents.

In this paper, the main chemical properties of Perilla seed oil (PO) obtained by mechanical pressing of Perilla seeds are reported. The analysis of fatty acid composition has highlighted a very high amount of (n-3) α-linolenic acid (ALA), more than 60%, higher than other ALA rich oils such as linseed and sacha inchi oils and similar to chia oil. PO has an important sterol (higher than 3000 mg/kg) and vitamin E (approx. 870 mg/kg) content, while biophenols are in quite low concentration. The analyzed sample showed a very low acid and peroxide value and this is the demonstration that, following the proper technological procedures, it is possible to obtain high quality oils even in presence of high α-linolenic acid concentrations.