Physicochemical, Textural, Thermal Properties of Rice Bran Oil Spread as Alternate Shortening for Bakery Products

The rice bran oil (RBO) can form its semisolid spread through solvent fractionation. The rice bran oil spread (RBOS) is proposed to be included in the production of bakery products. The aim of this is study is to compare the physicochemical, textural properties and thermal properties of RBOS with commercial shortening (CS). Spreadability analysis was conducted using a texture analyzer. There was no significant difference (p > 0.05) in firmness and work of shear between CS and RBOS. The fatty acid compositions were determined through GC-MS. The major fatty acids in RBOS were palmitic acid, oleic acid and linoleic acid which is similar to those in RBO but significantly (p < 0.05) higher in saturated fatty acid content. RBO contains a high amount of γ-oryzanol and phytosterols which is beneficial in solid fat structuring. The quantitation of γ-oryzanol was performed by using UV-Vis spectrophotometer while the phytosterol content was analyzed by using HPLC. There was no significant difference (p > 0.05) in γ-oryzanol between RBO (1,299.88 ± 50.97 mg/ 100 g sample) and RBOS (1,201.86 ± 84.37 mg/ 100 g sample). However, there was a significant difference (p < 0.05) in phytosterols between CS (4.17 ± 0.26 mg/ 100 g sample), RBO (247.00 ± 0.89 mg/ 100 g sample) and RBOS (184.16 ± 0.56 mg/ 100 g sample). Besides, thermal analysis of CS and RBOS were carried out using DSC and TGA. The similar textural properties but better physicochemical properties make RBOS becomes a suitable choice as alternate shortening for bakery product.

Relationship between Antioxidant Components and Oxidative Stability of Peanut Oils as Affected by Roasting Temperatures

The study sought to investigate the effect of roasting temperatures on antioxidant components and oxidative stability of peanut oils. The total phenolic content, total flavonoid content, α–tocopherol content, and phytosterol content in peanut oils was influenced by roasting at temperatures of 120 °C, 140 °C, and 160 °C, while those roasting temperatures had no effect on the fatty acid profile and γ–tocopherol content of peanut oils. Roasting promotes the quality of peanut oil aroma via the Maillard reaction, particularly when it is derived from N–heterocyclic compounds (such as pyrazine and pyrrole). The oxidative stability of peanut oils was investigated using the Rancimat method, and the results show that there is a linear relationship between roasting and natural logarithm of the induction period (R2: 0.959~0.998). This was determined based on the Arrhenius equation, which indicated the activation energy (Ea) was in the range of 82.08~108.61 kJ/mol. In principal component analysis (PCA) analysis, the antioxidant stability of the increase levels of phenols released in the peanut oils was found to rise with the increment of roasting temperatures. The data obtained in this study should be confirmed as the nutritional benefits of peanut oils that will be most appealing to consumers.

Enhancing the extraction of pumpkin seed (Cucurbita pepo L) for increasing oil yield and its phytosterol content

Pumpkin seeds (Cucurbita pepo) were harvested in 2018 containing 41.23±1.23% oil; 33.18±1.61% protein; and 1575.97 ±67.79 mg phytosterol in 100g seeds (dried weight). Solvent (hexane) extraction (SE), Ultrasound assisted solvent (hexane) extraction (UAE), Enzyme Alcalase assisted extraction (EAE) and Enzyme Alcalase_Ultrasound assisted extraction (E_UAE) were studied. The oil’s yields and phytosterol in oil obtained were 90.07±0.17% and 1657.6±82.9 mg/100ml oil; 95.46±0.06% and 2017.5±100.1 mg/100ml oil; 89.65±0.11% and 1992.7±99.5 mg/100ml oil; 91.87± 0.03% and 2327.7 ±110.4 mg/100ml oil, respectively. The highest oil yield of 95.56% was obtained when UAE method was applied, while it was found that the highest phytosterol content of 881.7 mg/100g seeds can be obtained in the case of using E_UAE.

Characteristics and Antioxidant Potential of Cold-Pressed Oils—Possible Strategies to Improve Oil Stability

The relations of the antiradical capacity to oxidative stability parameters and the contents of fatty acids, sterols, tocopherols, phenols, flavonoids, chlorophyll, Cu, and Fe were assessed in 33 cold-pressed seed oils: Walnut (7 brands of oils), rosehip (3), camelina (6), milk thistle (5), flax (6), and pumpkin (6). The antiradical capacity of oils depended strongly on tocopherol contents with a synergistic effect with polyphenols. The efficacy of tocopherols in cold-pressed oils was accompanied by a negative correlation of their antioxidant capacity with the peroxide value increase after 3 months of shelf life. This study also showed a positive correlation between the content of phytosterols and the antiradical capacity in the lipophilic fraction of cold-pressed oils rich in n-3 polyunsaturated fatty acids (PUFAs). Multiple regression analysis identified groups of antioxidants naturally occurring in cold-pressed oils in relation to their fatty acid composition, which added to the cold-pressed oils could provide possible strategies to improve their stability. Achieving high stability is primarily a result of high phytosterol content exceeding the molar ratio of 1:100 for total phytosterols to α-linolenic acid. However, the molar ratios of tocopherols to linoleic acid below 1:2000 and polyphenols to linoleic acid below 1:3000 does not prevent oxidation in oils with the predominance of linoleic acid.

Determination and Comparison of the Lipid Profile and Sodium Content of Gluten-Free and Gluten-Containing Breads from the Spanish Market

The objective is to verify if gluten-free (GF) and gluten-containing (G) breads differ in their sodium content and lipid profile. Samples of GF (n = 20) and G (n = 14) sliced white sandwich bread of commercial brands most frequently consumed in Spain were collected. The fatty acid (FA) composition and the contents of sodium, fat, cholesterol and phytosterols were determined. Sodium, fat and cholesterol contents were significantly higher in GF bread. The FA composition also differed, while G breads declared in most instances the use of sunflower oil as fat ingredient and presented a higher polyunsaturated FA percentage; GF breads declared a wide variety of fats and oils as ingredients (coconut, palm, olive, sunflower, etc.) which was reflected in their FA profile. Cholesterol content was higher in GF bread because five samples declared the use of whole egg, while G samples did not include any egg product in their formulas. Phytosterol content was higher in G bread but its variability was greater in GF bread. In conclusion, nutritional quality of GF bread varied depending on the ingredients used and might be lower than that of G bread. However, these differences in composition could be reduced or eliminated through changes in the formulation of GF bread. Moreover, the comparison of the results obtained in our laboratory for fat and salt content with the declared contents on the labels showed a much higher deviation for GF samples and it can be concluded that the quality of the nutritional information declared was lower in GF samples.

Optimization of the condition of phytosterol extraction conditions from microalgae nannochloropsis using ethanol of different purity levels

Phytosterols are plant sterols, included in secondary metabolite compounds and have broad benefits in the health field. This study aims to observe the effect of ethanol solvency purity, time of extraction on phytosterol content. The extraction was carried out by saponification using a 7.5% KOH solution in ethanol. The variations in extraction time are 1, 2, 3, and 4 hours. Ethanol used varies purity levels, i.e technical 70%, technical 96%, and pure analysis. The variations in maceration time are 1, 2 and 3 days. The results showed that all ethanol solvents with different purity levels resulted in the highest crude phytosterol under long duration of 1 hour extraction time. The ethanol purity rate had a significant effect on the yield of phytosterol produced, i.e., 70% technical, 96% technical, and pure analysis consume 0.4%, 1.63% and 4.19% crude phytosterol, respectively. J. bio-sci. 27: 143-148, 2019

High-Performance Thin-Layer Chromatography Hyphenated with Microchemical and Biochemical Derivatizations in Bioactivity Profiling of Marine Species

Marine organisms produce an array of biologically active natural products, many of which have unique structures that have not been found in terrestrial organisms. Hence, marine algae provide a unique source of bioactive compounds. The present study investigated 19 marine algae and one seagrass collected from Torquay beach, Victoria, Australia. High-performance thin-layer chromatography (HPTLC) hyphenated with microchemical (DPPH•, p-anisaldehyde, and Fast Blue B) and biochemical (α-amylase and acetylcholine esterase (AChE) enzymatic) derivatizations was used to evaluate antioxidant activity, presence of phytosterols and phenolic lipids, α-amylase and AChE inhibitory activities of extract components. Significant α-amylase and AChE inhibitory activities were observed in samples 2, 6, 8 and 10. Antioxidant activities in the samples were found to be correlated to phytosterol content (R2 = 0.78), but was not found to be related to either α-amylase or AChE inhibitory activities. α-Amylase inhibitory activities were correlated to AChE inhibition (R2 = 0.77) and attributed to the phytosterol content, based on the similar peak position in the chromatograms with the β-sitosterol chromatogram. Samples 1, 8, and especially sample 20, were found to contain phenolic lipids (alkyl resorcinol derivatives) with significant antioxidant activities. The results suggest that these marine species have a significant number of bioactive compounds that warrant further investigation.