Effect of heat processing on the profiles of trans fatty acids and conjugated linoleic acid in butter oil

Sman or traditional butter oil (TBO) is known to be rich in saturated fatty acids (SFA). Meanwhile, published information about trans fatty acids (TFAs) content in TBO remains unexplored. Therefore, a comparison of the fatty acid (FA) composition of traditional butter (TB) and (TBO) with emphasis on geometric and conjugated linoleic acid (CLA) isomers was undertaken. Both TB and TBO accounted for a high level of SFA with significant high content in TBO (p < 0.05). Total TFAs in TBO were more than twice the content in TB (8.23% vs. 3.85%, respectively, p < 0.01). An increase by 1.81 and 2.9 times was observed for trans monounsaturated FAs and trans polyunsaturated FAs in TBO compared to TB, respectively. Vaccenic acid (VA), the predominant TFA in both TB and TBO, was increased by 100% in TBO (p < 0.001). Trans-linoleic acid isomers were 1.84-fold higher in TBO than in TB. The contribution that CLA made to the total FA was increased by 1.48-fold for TBO. In general, it was found that TBO contains high levels of TFAs and CLA. Thus, TBO represents a mixture of FAs with different configurations from natural and technological origins, having potential conflicting effects on human health.Keywords: Trans-fatty acids, conjugated linoleic acid, butter oilAfrican Journal of Biotechnology Vol. 12(21), pp. 3333-334

Incidence of dairy wastewater on morphological and physiological comportment of Chemlali and Chetoui olive

In the present study the analysis of the physico-chemical parameters of the collected TWW shows the BOD, COD, COT, Cl-, NO3, NO2, suspended matter, organic matter, turbidity and conductivity were in accordance with the required Tunisian legislations. In the same occurrence, the ICP-MS and the UPLC-MS/MS analysis show that TWW were devoid of different toxic metals and antibiotics, respectively. We opted to reuse of the TWW in the irrigation of young olive trees of two varieties: Olea europaea L. cv. Chetoui and Olea europaea L. cv. Chemlali which receiving 1 L/week of TWW during five months. Results show that dry roots weight and the content of chlorophyll a in 'Chetoui' variety increased significantly (p < 0.05) when compared to the control group. On the same way, significantly increase of leaf area, dry roots and leaves weights was observed in 'Chemlali' variety treated with TWW. Keywords: Dairy wastewater, Reuse wastewater, Olea europaea L., ICP-MS, UPLC-MS/M

Butylated Hydroxytoluene (BHT) emitted by fungi naturally occurring in olives during their pre-processing storage for improving olive oil stability

Extra virgin olive oil is widely consumed because of its nutritional benefits and sensory properties which are very important to be preserved in the product. Therefore, chemically synthesized compounds, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), are widely used as antioxidants in oil products. It is well known that the activity of some micro-organisms able to oxidize free fatty acids can lead to the loss of the stability of the final product. Nevertheless, several researchers have been recently motivated to evaluate the potential of micro-organisms on the production of bioactive compounds. In this paper headspace solid micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were used for the characterization and investigation of Fungal Organic Volatile Metabolites (FOVCs) emitted by 14 fungal strains isolated from olives during their pre-processing storage. A wide range of volatile compounds were detected among them, Butylated Hydroxytoluene (BHT) was produced at levels ranging between 0.3 and 13.1%. This compound could be considered for the industry as natural antioxidant to substitute the synthetic ones used for ameliorating the stability of olive oil and other fatty food products. Practical applications: As the pre-processing storage step is inevitable for several practical reasons, inducing the outgrowth of olive microflora (mainly fungi), which critically affect the physiological state of the fruit and thus the quality of the correspondent oil, this paper try to elucidate the potential of these naturally developing strains and their metabolites (FVOCs) of producing bioactive compounds mainly the Butylated Hydroxytoluene (BHT) which could be considered by the industry in order to substitute the synthetic one largely used to improve the stability of olive oil and other food products. Volatiles, when coupled with the power “omics” technologies represent a new frontier in bio-prospectin

Study of phenolic composition of olive fruits: validation of a simple and fast HPLC-UV method

A high-performance liquid chromatography (HPLC) method endowed with a gradient elution and a UV detection system was established and validated for the determination of phenolic acids, phenolic alcohols, hydroxycinnamic acid derivatives, flavonoids, secoiridoids and lignans during olive (Olea europaea L.) fruit development (green, purple and black olives). Within the test range, the calibration curves exposed a good linear regression (R 2>0.9995). Detection limits ranged between 0.63 and 13.43 mg/L for the detected phenolic compounds. The presented method yielded satisfactory repeatability in terms of retention times and average concentrations of phenolic compounds (RSD < 0.3%). Verbascoside was established as the major phenolic compound in black olives. Oleuropein was established as the dominating phenolic compound in green olives, and its level decreased during maturation. Additionally, this research is the first to experimentally evidence that the flavone luteolin-7-rutinoside is the predominant flavonoid glucoside in black olives, showing the most significant variation with fruit development. The above results validate the method for an easy and fast determination of different classes of phenolic compounds present in olive fruits

Oil Characterization and Lipids Class Composition of Pomegranate Seeds

This study aims to investigate the physicochemical characteristics, phenolics content, and oil composition of pomegranate oil seeds (PSO). Quality indices, pigments, phenolics content, and antioxidant activity were determined. PSO was fractioned into polar lipids: glycolipids (GL) and phospholipids (PL). Sterols profile and fatty acids composition of total lipids (TL), GL, and PL were determined by GC/FID. The free acidity, the peroxide value, and the specific extinction coefficients were, respectively, 1.69%, 3.42 in milliequivalents of active oxygen per kilogram of oil, 4.15, and 3.95. PSO is rich in phenols (93.42 mg/Kg) but poor in pigments. The sterols markers were β-sitosterol (77.94%), Δ5-avenasterol (7.45%), and campesterol (6.35%). Oil content was 12.2%, wherein 23.9% were GL and 24.35% were PL. TL were rich in unsaturated fatty acids (63.17%), while saturated fatty acids were more present in PL and GL (71.97% and 66.29%, resp.). Conjugated fatty acids were about 13.30%, 2.03%, and 4.91%, respectively, in TL, PL, and GL. The cis/trans ratio of TL, PL, and GL was, respectively, 49.82%, 42.91%, and 27.39%. Monounsaturated fatty acids were more bound in PL, whereas polyunsaturated fatty acids were more bound in GL. PSO is a good source of essential fatty acids, phenolics compounds, phytosterols, and lipid-soluble fractions

Discrimination of some tunisian olive oil varieties according to their oxidative stability, volatiles compounds and chemometric analysis

Oxidation stability is a key property of olive oil quality and is affected by different antioxidant compounds whose levels may be influenced by several factors such as cultivar and place of production. Polyphenols, carotenoids, chlorophylls, fatty acids levels and some volatiles were correlated to oxidative stability in olive oils in five samples studied. Total polyphenols and saturated to polyunsaturated fatty acids (and/or oleic to linoleic acid ratio) ratio were shown to be the major parameters in oil antioxidant stability, according to analysis of variance and principal component analysis. The hexanal/E-2-hexenal ratio is a very important indicator of the freshness of the oils and can estimate their oxidation degre

Modification of pomological characteristics and flavor components of fruits and virgin olive oil following wastewater irrigation and soil tillage

BACKGROUND The experiment was carried out on olive trees cv. Chemlali, during two successive years (2013/2014). Two irrigation treatments (IT: Trees irrigated with wastewater; TRC: Trees grown under rainfed condition) were combined with two tillage practices (TTS: Trees grown in tilled soil; TNTS: Trees grown in non-tilled soil). RESULTS The results of the study showed that WW irrigation combined with soil tillage improved the pomological characteristics of olive fruits. The tree yield increase was substantial for IT and TTS. However, most of the identified phenolic compounds, especially oleuropein, mainly accumulated in olive fruits of the TC block (TNTS + TRC), suggesting a marked improvement in the nutritional value of these fruits. Moreover, fruits of TNTS had high contents of sugar compounds, required for the synthesis of the fruit storage material. The study also showed that the agronomic practices affected the amounts of some aromatic compounds responsible for the distinctive flavor notes of olive oil. CONCLUSION Hence, agronomic practices may affect considerably the commercial and nutritional values and the sensorial quality of the commodities