Goldenberry (Physalis peruviana L.) seed oil: press extraction, optimization, characterization, and oxidative stability

In order to optimize the screw-press extraction conditions of oil from goldenberry (Physalis peruviana L.) seeds obtained from nectar processing waste, a face centered design was applied. The oil was extracted at different temperatures (60, 80, and 100°C) and seed moisture contents (8, 10, and 12%). Oil recovery (OR) increased and residual oil in the cake decreased significantly as moisture content and temperature were reduced; oil moisture and volatile matter as well as acid value, K232, K268, and p-anisidine, respectively, decreased proportionally with the moisture extraction. Thus, the highest OR (86.4%) and the best quality were obtained at 8% moisture content and 60°C pressing temperature. Under these conditions, the extracted oil presented high linoleic acid (76.0%), iodine value (140.0 mg I2/g), and refractive index (1.4769). The oil stability index, measured by Rancimat, varied from 3.65 h (120°C) to 14.87 h (100°C); the predicted shelf life at 25°C was 120.4 days and the activation energy was 85.6 kJ/mol. The results highlighted that screw-pressing of goldenberry seeds provides quality oil without employing polluting and hazardous solvents.

Physicochemical Characteristics and Thermal Stability of Perilla Seed Oil of Indian Origin

There is an increasing interest of food scientists in finding new alternatives to PUFA rich edible oil. Perilla seed oil (CPSO), an underutilized oilseed, can be used as an edible oil source. Oil extracted by the cold-pressed method from perilla seeds gives a yield of 36.50%. This study reports the physicochemical properties, the oxidative and thermal stability of the cold-pressed perilla seed oil. The viscosity, specific gravity, refractive index, and smoke point of CPSO were 28 m.Pa.s, 0.92, 1.43, and 241 ℃, respectively. The peroxide, acid, iodine, saponification value, and unsaponified matter of CPSO were 4.81 meq O2/kg oil, 1.61 g KOH/kg oil, 132 g KOH/kg oil, 180 g I2/kg oil, and 0.64%, respectively. It consists of high α -linolenic acid (55.80% of total oil) followed by oleic acid (20.54%). The extracted oil is analyzed for its thermal stability (peroxide value, free fatty acids, p- anisidine value, totox value, and total polar compounds) and storage stability for 120 days in two different storage conditions (refrigerated and room temperature). Despite having high nutritional benefits, the oil stability index (0.50 h) of the perilla seed oil is low, limiting its utilization as a frying oil. Therefore, perilla seed oil requires process optimization to increase its stability during heating.

Effect of Pulsed Electric Fields (PEF) on Extraction Yield and Stability of Oil Obtained from Dry Pecan Nuts (Carya illinoinensis (Wangenh. K. Koch))

Pulsed electric fields (PEF) have been reported to increase the total oil extraction yield (OEYTOTAL) of fresh pecan nuts maintaining oil characteristics and increasing phenolic compounds in the remaining by-product. However, there is no information regarding the PEF effect on dry pecan nuts. Dry kernels were pretreated at three specific energy inputs (0.8, 7.8 and 15.0 kJ/kg) and compared against untreated kernels and kernels soaked at 3, 20 and 35 min. OEYTOTAL, kernels microstructure, oil stability (acidity, antioxidant capacity (AC), oil stability index, phytosterols and lipoxygenase activity), along with by-products phenolic compounds (total phenolics (TP), condensed tannins (CT)) and AC were evaluated. Untreated kernels yielded 88.7 ± 3.0%, whereas OEYTOTAL of soaked and PEF-treated kernels were 76.5–83.0 and 79.8–85.0%, respectively. Kernels microstructural analysis evidenced that the 0.8 kJ/kg pretreatment induced oleosomes fusion, while no differences were observed in the stability of extracted oils. PEF applied at 0.8 kJ/kg also increased by-products CT by 27.0–43.5% and AC by 21.8–24.3% compared to soaked and untreated kernels. These results showed that PEF does not improve OEYTOTAL when it is applied to dry pecan nuts, demonstrating that kernelsʹ moisture, oil content and microstructure play an important role in the effectiveness of PEF.

Comparison of Bioactive Compounds of Matricaria recutita Extracted by Ultrasound and Maceration and their Effects on Preventing Sunflower Oil During Frying

Background: It is important to study about the use of natural antioxidants as alternatives to synthetic ones due to the possibility of carcinogenic effects of synthetic antioxidants. This study is comparing the effect of the ultrasound-assisted and maceration extraction methods on antioxidant activity of Matricaria recutita. Methods: Bioactive compounds including phenolic, tocopherol, flavonoid and tannins and antioxidant activity of the extracts were evaluated. Moreover, extracts obtained from ultrasound and maceration methods were added to sunflower oil without any antioxidants at level of 200, 500 and 800 ppm, after that samples were heated at 180°C. Oxidation of the samples were evaluated after 0, 4, 8, 12, 16, 20 and 24 hours by measuring Peroxide Value (PV), Conjugated Diene (CD), Iodine Value (IV), Carbonyl Value (CV), Total Polar Compounds (TPC), Oil Stability Index (OSI), Color Index (CI) and acid value (AV). Results: The result showed total phenol (42.90 mg gallic acid/g extract), tocopherol (120.46 µg α - tocopherol/ml extract), flavonoid (2.64 mg/100 g extract) and tannins (3.89 mg gallic acid/g extract) of ultrasound extracts were higher than maceration extracts. Antioxidant activity of the extract was evaluated by DPPH assay which indicated 800 ppm of the Matricaria recutita extracted by ultrasound was the highest radical scavenging ability. Conclusion: Result indicated both ultrasound and maceration extracts could increase the oil oxidative stability but could not increase compared to BHA. In most cases, the extract samples by ultrasound had a better effect on stabilizing of sunflower oil during frying.

Application of Peanut Butter to Improve the Nutritional Quality of Cookies

The study on Hydrogenated fat replaced with peanut butter to reduce saturated fatty acids in cookies was carried out. Cookies prepared with varied concentrations of hydrogenated fat and peanut butter (100:00, 80:20, 60:40, 40:60, 20:80 and 00:100) were analyzed to check fatty acid composition and textural characteristics. Palmitic acid, Myristic acid and Stearic acid (Saturated fatty acids) were higher in Control cookies, which level was reduced with increasing concentration of PB in different treatments. Linoleic acid and Oleic acid (Unsaturated fatty acids) were lower in control cookies, which were increased with increasing concentration of Peanut butter in different treatments. Oil stability index of experimental cookies increased up to 3.62% with increasing concentration of PB. Cookies hardness was also increased with increasing concentration of PB. Cookies with 40% PB had beneficial fatty acid composition with stable oil quality and also had a greater appreciable sensory quality by evaluation panel. Objective: Preparation of peanut butter Preparation of cookies in different ratio of vegetable fat to peanut butter Texture analysis and sensory quality Fatty acid profiling

Lipid oxidation of fat blends modified by monoacylglycerol

Model dispersions of fat blends (FBs) with monoacylglycerols (MAG) of saturated fatty acids with different lengths of the acyl chain (MAG10–MAG18) and 1-octadecenoylglycerol and without MAG (as blank) were prepared. We find out the influence of the addition of monoacylglycerol on oxidation of the fat dispersion. Trihexadecanoylglycerol (tripalmitoylglycerol – TAG48) was used as the dispersive phase and soybean oil was used as the dispersive medium. Primary (conjugated diens) and volatile secondary (by SPME in connection with GC-MS) lipid oxidation products and oil stability index (OSI) were measured during autoxidation of the fat blends in storage conditions. MAGs with a shorter (or the same) acyl chain length (MAG10–MAG16) than the acyl chain length of the structured fat (TAG48) arrange tightly on the interface oil/crystals of structured fat, thus prevent lipid oxidation.

Isolation of some compounds from nutmeg and their antioxidant activities

Six compounds, licarin-B (1), dehydrodiisoeugenol (2), malabaricone B (3), malabaricone C (4), β-sitosterol (5), and daucosterol (6) were isolated from the seed (nutmeg) of Myristica fragrans Houtt and identified. Among them, malabaricone B was identified for the first time in nutmeg. Antioxidant activities of the isolated compounds were studied using oil stability index (OSI), reducing power, ABTS^●+ scavenging, and DPPH^● scavenging methods. The results showed that Malabaricone C is an efficient antioxidant agent which exhibits a stronger antioxidant activity than the commonly used synthetic antioxidants in all studied methods. This compound may have a potential to be used as a natural antioxidant in food.