Membrane Fatty Acids And Physiological Disorders in Cold Stored ‘Golden Delicious’ Apples Treated with 1-MCP and Calcium Chloride

The present research intents to study the evolution of the skin fatty acids and physiological disorders through cold storage in ‘Golden Delicious’ apples treated with 1-MCP and calcium. Harvested fruit were treated with calcium chloride (Ca), 1-MCP (MCP), Ca+MCP or no treatment (control) then subjected to cold storage at 0.5 ºC for 6 months. Fatty acids composition, Malondialdehyde (MDA) and the physiological disorders bitter pit (BP), superficial scald and diffuse skin browning (DSB) were measured at harvest and after storage plus 7 days shelf-life at room temperature ≈22 ºC. Palmitic acid decreased and linoleic acid increased through time, while oleic and stearic acids had few changes. Unsaturated/saturated fatty acids and MDA increased through time, despite Ca and Ca+MCP were related to lower MDA and lower BP and rotten fruit, after cold storage and shelf-life. In those treatments, the unsaturated/saturated fatty acids were higher, mainly due to higher linoleic acid and lower palmitic acids. Further research is needed to clarify the changes in membrane properties and the effect of some treatments in response to chilling injury through storage.

Dietary Alpha-Linolenic Acid Supports High Retinal DHA Levels

The retina requires docosahexaenoic acid (DHA) for optimal function. Alpha-linolenic acid (ALA) and DHA are dietary sources of retinal DHA. This research investigated optimizing retinal DHA using dietary ALA. Previous research identified 19% DHA in retinal phospholipids was associated with optimal retinal function in guinea pigs. Pregnant guinea pigs were fed dietary ALA from 2.8% to 17.3% of diet fatty acids, at a constant level of linoleic acid (LA) of 18% for the last one third of gestation and retinal DHA levels were assessed in 3-week-old offspring maintained on the same diets as their mothers. Retinal DHA increased in a linear fashion with the maximum on the diet with LA:ALA of 1:1. Feeding diets with LA:ALA of 1:1 during pregnancy and assessing retinal DHA in 3-week-old offspring was associated with optimized retinal DHA levels. We speculate that the current intakes of ALA in human diets, especially in relation to LA intakes, are inadequate to support high DHA levels in the retina.

Variability of Essential and Nonessential Fatty Acids of Irish Rapeseed Oils as an Indicator of Nutritional Quality

The low saturated fatty acid content of rapeseed oil has resulted in it being classed as one of the most health-benefiting culinary oils. This study determines whether Irish rapeseed oils contain identical fatty acid profiles or whether distinct profiles exist between producers and producers’ successive oil batches. The fatty acid content of Irish rapeseed oils was determined in terms of the desirable MUFA and PUFA and saturated content of these oils. The fatty acid composition demonstrated significant differences in individual unsaturated fatty acid content, while total saturation had insignificant differences. Saturated fatty acid content ranged from 6.10 to 15.8%, while unsaturated fatty acids ranged from 84.20 to 90.10%. Moreover, individual fatty acid content exhibited significant differences ( p < 0.05 ). Oleic acid (C18:1), linoleic acid (C18:2), and stearic acid (C18:0) contents were considered significantly different from other fatty acids detected. The third successive batch from each producer exhibited lower oleic acid content, and the third batch contained higher linoleic acid content, at the same time maintaining a desirable unsaturated fatty acid composition. Studies suggest that differences in the fatty acid composition may be due to cultivation practices such as climate, soil composition, sowing and harvesting, processing techniques, and oxidation reactions.

Responses of Bloom-Forming Heterosigma akashiwo to Allelochemical Linoleic Acid: Growth Inhibition, Oxidative Stress and Apoptosis

Algal blooms have been occurring in many regions worldwide, and allelochemicals are important algaecides used to control harmful algal blooms (HABs). The allelopathic effects of linoleic acid (LA) on the harmful raphidophyte Heterosigma akashiwo were studied, and the possible mechanisms were investigated through analyses of population growth dynamics, cellular ultrastructure and the physiological levels of H. akashiwo. The results showed that the inhibitory effect of LA on H. akashiwo cells increased with an increasing LA concentration. The levels of ROS and MDA were significantly elevated, indicating oxidative stress and lipid peroxidation due to LA exposure. At the same time, LA also activated the antioxidant system, including superoxide dismutase (SOD), catalase (CAT), and POD, and non-enzymatic antioxidants such as reduced AsA and glutathione (GSH). Transmission electron microscopy (TEM) revealed that the morphology of the algal cells was impaired in an LA-dependent manner. Annexin V-FITC/PI double staining and flow cytometric analysis revealed that LA exposure decreased the cellular mitochondrial membrane potential (MMP), increased the rate of apoptosis. LA modulated bcl-2/bax homeostasis and increased the expressions of cytochrome c and caspases-3 and -9, proving that LA induced cell death via the mitochondria-mediated apoptotic pathway. It was suggested that LA had allelopathic effects on H. akashiwo, inducing physiological and morphological changes and finally triggering the apoptosis of H. akashiwo. All of these results showed that LA might have the potential as an algaecide to control harmful algae.

Comparative chemical profiling and antimicrobial activity of Nigella sativa seeds oils obtained from different sources

<i>Nigella sativa</i> L. seeds are widely used in Sudan as a spice, food preservative, and medicine. Sudan does not grow the plant. The study aimed to compare the chemical profile and antibacterial activity of fixed and essential oils of <i>N. sativa</i> from Ethiopian and Indian seeds and the oil offered by Attarin in the local market. A Soxhlet device extracted fixed oils and hydrodistillation to obtain essential oils and analysed their oil profile using GC-MS. Disk diffusion was used to test antimicrobial activity. The fixed oil of Ethiopian (EFO) and Indian (IFO) seeds contained ten components, with linoleic acid (50.12% in EFO and 57.69% in IFO) being the most abundant. Ethiopian seeds were used to extract the essential oil. 51.96% of the oil was hydrogenated monoterpenes. The main chemicals were p-cymene (36.76%) and thymoquinone (18.70%). There were fixed and essential oils in the Attarin oil sample. The main component was linoleic acid (14.61%), followed by p-cymene (13.85%). The maximum antibacterial activity (MIC 6.25 µg/disc) was seen in both fixed and liquid oil samples against Escherichia coli and Pseudomonas aeruginosa. The best anti-<i>P. aeruginosa</i> action was attarin oil (MIC 12.5 µg/disc). Finally, the Sudanese market needs to standardise <i>N. sativa</i> seeds and oil.

A Novel Insight into Screening for Antioxidant Peptides from Hazelnut Protein: Based on the Properties of Amino Acid Residues

This study used the properties of amino acid residues to screen antioxidant peptides from hazelnut protein. It was confirmed that the type and position of amino acid residues, grand average of hydropathy, and molecular weight of a peptide could be comprehensively applied to obtain desirable antioxidants after analyzing the information of synthesized dipeptides and BIOPEP database. As a result, six peptides, FSEY, QIESW, SEGFEW, IDLGTTY, GEGFFEM, and NLNQCQRYM were identified from hazelnut protein hydrolysates with higher antioxidant capacity than reduced Glutathione (GSH) against linoleic acid oxidation. The peptides having Tyr residue at C-terminal were found to prohibit the oxidation of linoleic acid better than others. Among them, peptide FSEY inhibited the rancidity of hazelnut oil very well in an oil-in-water emulsion. Additionally, quantum chemical parameters proved Tyr-residue to act as the active site of FSEY are responsible for its antioxidation. This is the first presentation of a novel approach to excavating desired antioxidant peptides against lipid oxidation from hazelnut protein via the properties of amino acid residues.