Stability and rheology of concentrated of concentrated O/W emulsions based on soybean oil/palm kernel olein blends.

Droplet size distribution and rheological properties of egg yolk-stabilized emulsions were studied before and after storage (25 °C, 30 days). The dispersed phase (70%) of the emulsions was based on soybean oil (SBO) and 10–40% palm kernel olein (PKO) replacements of SBO. Replacement of PKO resulted in a significant increase in droplet mean diameters and a decrease in rheological properties of the emulsions. All emulsion exhibited a gel-like characteristic with storage modulus higher than loss modulus and tan δ greater than 0.3. Significant increase (p < 0.05) was found for droplet mean diameters and rheological properties of the emulsions after storage. Emulsion with fully SBO and the highest PKO replacement (40%) were found to be the most unstable, which was ascribed to a strong flocculation. With 10–30% PKO replacements, the emulsions displayed a better stability after storage, most probably promoted by significant content of short-medium chain fatty acids in PKO

Droplet characterization and stability of soybean oil/palm kernel olein O/W emulsions with the presence of selected polysaccharides.

Droplet characteristics, flow properties and stability of egg yolk-stabilized oil-in-water (O/W) emulsions as affected by the presence of xanthan gum (XG), carboxymethyl cellulose (CMC), guar gum (GG), locust bean gum (LBG) and gum Arabic (AG) were studied. The dispersed phase (40%) of the emulsions was based on soybean oil/palm kernel olein blend (70:30) that partially crystallized during extended storage at 5 °C. In freshly prepared emulsions, the presence of XG, CMC, GG and LBG had significantly decreased the droplet mean diameters. XG, LBG, GG and CMC emulsions exhibited a shear-thinning behavior but AG emulsion exhibited a Bingham plastic behavior and control (without gum) emulsion almost exhibited a Newtonian behavior. Both control and AG emulsions exhibited a severe phase separation after storage (30 days, 5 °C). The microstructure of stored XG emulsion showed the presence of partially coalesced droplets, explaining a large increase in its droplet mean diameters. Increases in droplet mean diameters and decreases in flow properties found for stored GG and LBG emulsions were attributed to droplet coalescence. Nevertheless, the occurrence of droplet coalescence in these emulsions was considered to be small as no free oil could be separated under centrifugation force. Increases in flow properties and excellent stability towards phase separation found for stored CMC emulsion suggested that CMC could retard partial coalescence. Thus, the results support the ability of CMC, GG and LBG in reducing partial coalescence either by providing a sufficiently thick continuous phase or by acting as a protective coating for oil droplets

Effect of frying process on fatty acid composition and iodine value of selected vegetable oils and their blends

The main objective of the present study was to investigate the effects of the frying media and storage time on the fatty acid composition (FAC) and iodine value (IV) of deep-fat fried potato chips. The frying experiment was conducted at 180ºC for five consecutive days. Six frying media were considered as the main treatments: refined, bleached, deodorized (RBD) palm olein (A), canola oil (C), RBD palm olein/sesame oil (AB, 1:1 w/w), RBD palm olein/canola oil (AC, 1:1, w/w), sesame oil/canola oil (BC, 1:1, w/w), and RBD palm olein/sesame oil/canola oil (ABC, 1:1:1, w/w/w). The initial degrees of unsaturation of the consumed oils, A, C, AB, AC, BC, and ABC, were 58.6, 94.0, 68.0, 72.2, 87.7, and 75.8 (g/100 g), respectively. The fatty acid analysis showed that there was a decrease in both the linolenic acid (C18:3) and linoleic acid (C18:2) contents, whereas the palmitic acid (C16:0) increased with a prolonged frying time. The chemical analysis showed that there was a significant (p < 0.05) difference in terms of the IV for each frying oil during the five consecutive days of frying (day 0 to 5). Oil C had the least stability in terms of deep-fat frying due to a high level of unsaturated fatty acids. Conversely, oil AC had the best stability due to the smallest reduction of the C18:2/C16:0 ratio and the IV

Proximate and fatty acid composition of liver and fatty tissue of patin catfish (Pangasianodon hypophthalmus)

The visceral storage fat and liver of patin catfish (Pangasianodon hypophthalmus) are normally discarded, which incurs cost and can cause environmental pollution. However, these may be potential sources to extract fish oil. The proximate and fatty acid compositions of liver and fatty tissue of patin catfish were investigated to evaluate the suitability of these by-products for extracting fish oil. Fat was extracted using a low temperature solvent extraction method. The average fat content of fatty tissue and liver of females were 77.64 and 11.71%, respectively, whereas in males this was73.23 and 9.59%, respectively. Fatty acids found in the extracted oil of these byproducts were C12:0, C14:0, C14:1, C16:0, C16:1, C18:0, C18:1, C18:2, C18:3, C18:4, C20:0, C20:1, C20:4, C20:5, and C22:6.The major fatty acids presented in these tissues were palmitic (C16:0), oleic (C18:1n-9), and linoleic acid (C18:2 n-6). The total amount of polyunsaturated fatty acids of liver from male and female patin catfish were 13.31 and 13.30%, respectively, whereas in the fatty tissue these were11.64 and 12.09%, respectively. The n-3 to n-6 ratios of liver and fatty tissue of females were 1.61and 0.95, respectively, whereas in male fish these were 1.31 and 1.05, respectively. Results of this study indicated that the liver and fatty tissues of patin catfish are suitable sources of fish oil specifically due to the presence of monounsaturated and n-3 polyunsaturated fatty acids

Lifespan-increasing drug nordihydroguaiaretic acid inhibits p300 and activates autophagy.

Aging is characterized by the progressive loss of physiological function in all organisms. Remarkably, the aging process can be modulated by environmental modifications, including diet and small molecules. The natural compound nordihydroguaiaretic acid (NDGA) robustly increases lifespan in flies and mice, but its mechanism of action remains unclear. Here, we report that NDGA is an inhibitor of the epigenetic regulator p300. We find that NDGA inhibits p300 acetyltransferase activity in vitro and suppresses acetylation of a key p300 target in histones (i.e., H3K27) in cells. We use the cellular thermal shift assay to uniquely demonstrate NDGA binding to p300 in cells. Finally, in agreement with recent findings indicating that p300 is a potent blocker of autophagy, we show that NDGA treatment induces autophagy. These findings identify p300 as a target of NDGA and provide mechanistic insight into its role in longevity

Physicochemical properties and bioactive compounds of selected seed oils.

The physicochemical properties and chemical composition of oil extracted from five varieties of plant seeds (bittermelon, Kalahari melon, kenaf, pumpkin and roselle seeds) were examined by established methods. The thermal properties of extracted oils by differential scanning calorimetry were also evaluated. Sensorial profiles of these seed oils were defined through the CieLab (L*, a*, b*) colour. Most of the quality indices and fatty acid compositions showed significant (P < 0.05) variations among the extracted oils. Physicochemical properties of the oils extracted were iodine value, 86.0–125.0 g I2/100 g oil; saponification value, 171.0–190.7 mg of KOH/g of oil; acid value, 1.1–12.9 mg of KOH/g of oil, free fatty acid, 0.6–6.5 g/100 g of oil, and peroxide value 1.5–6.5 meq of O2/kg of oil. Palmitic, oleic and linoleic acids were the major fatty acids in all of the extracted seed oils except for bittermelon, where eleostearic acid was the major fatty acid. Gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, pcoumaric and ferulic acids were identified in the extracted plant oils. Among these, vanillic acid was predominant in all extracted oils. The oils were rich in tocopherols with g-tocopherol as the major components in all oil samples. Among the phytosterols, sitosterol was the major phytosterol extracted from the five plant seed oils. The seeds of these plants contain a great number of valuable minor compounds, which have a potential high value as food and for production of non-food products

Thermal behavior of concentrated oil-in-water emulsions based on soybean oil and palm kernel olein blends

Droplet size distribution and thermal behavior of concentrated oil-in-water emulsions based on soybean oil (SBO)/palm kernel olein (PKO) blends were investigated. The emulsions were prepared using 70% (wt./wt.) oil blends of SBO/PKO as dispersed phases and stabilized by egg yolk. An increase in PKO level (0–40% wt./wt.) in the oil dispersed phase volume fraction caused significant increases (p < 0.05) in volume-weighted mean diameter (d4,3). The DSC data suggested that crystallization of the emulsions was induced by a ‘template effect’ of yolk constituents via a surface heterogeneous nucleation. Emulsions with 0–20% (wt./wt.) PKO levels in the dispersed phase demonstrated a good cool–heat stability even after three successive thermal cycles (from 50 °C to −70 °C at 10 min/°C). After the first thermal cycle, emulsions with 30% and 40% PKO levels in the oil dispersed phase were destabilized due to strong coalescence and crystallized via volume-surface heterogeneous nucleation. The unstable emulsions were attributable to high level of saturated triacylglycerols from PKO, with high droplet size characteristic, causing them to be more prone to partial coalescence