Effect of different oil extraction methods on bioactive compounds, antioxidant capacity and phytochemical profiles of raw flaxseeds (Linum usitatissimum) and after roasting at different temperatures.

BACKGROUND: Factors such as variety, genetics, soil structure and plant diseases affect the oil amount and properties of flaxseed. By applying heat and various extraction treatments to flaxseed, the storage ability of the seed is increased by the removal of moisture, and the stability of phytochemicals in the seed against heat can be determined. RESULTS: Total carotenoid and phenol of flaxseeds changed from 0.13 (control) and 0.61 mg g-1 (120 °C) to 202.64 (control and 90 °C) and 225.69 mg 100 g-1 (120 °C), respectively. While total flavonoid of flaxseed roasted at different temperatures varied between 636.0 (90 °C) and 786.00 mg 100 g-1 (120 °C), antioxidant activity values for raw and roasted flaxseeds between 59.32% (control) and 68.64% (120 °C) were recorded. Oil content of seeds changed between 34.07 and 42.57% (P < 0.05). Viscosity of flaxseed oil extracted using different systems was between 31.95 (cold-pressed; control) and 36.00 mPa s (ultrasonic; 120 °C). The dominant phenolics of flaxseeds were identified as isorhamnetin, resveratrol, quercetin, catechin, apigenin-7-glucoside and campherol. The oils of flaxseeds contained 55.27-58.23 linolenic, 17.40-18.91 oleic, 14.03-14.84 linoleic and 4.97-5.37 palmitic acids, depending on extraction method and roasting temperature. CONCLUSION: Roasting and oil extraction methods did not have a significant effect on free acidity, but was found to affect peroxide value. The predominant phenolic constituents of flaxseed samples were isorhamnetin, resveratrol, quercetin, catechin, apigenin-7-glucoside and campherol, respectively. The major fatty acids of flaxseed oil were determined as linolenic, oleic, linoleic and palmitic. © 2023 Society of Chemical Industry.

Effect of maltodextrin combination with gum arabic and whey protein isolate on the microencapsulation of gurum seed oil using a spray-drying method.

This study aimed to evaluate the potential of maltodextrin (MD) combination with gum arabic (GA), and whey protein isolate (WPI) on the microencapsulation of gurum seeds oil by a spray-drying method. Three formulations of protein-based (PB) (WPI: MD, 2:1), carbohydrate-based (CHOB) (GA: MD, 2:1), and mixed (MIX) (WPI: GA: MD, 1:1:1) wall materials were designed. The moisture content and water activity were in the range of 1.65-3.67% and 0.17-0.31, respectively, which is suitable for long-term storage. The best results were achieved when gurum seed oil was microencapsulated with carbohydrate-based, where it had the highest microencapsulation yield (92.80%) and microencapsulation efficiency (97.38%). Carbohydrate-based showed the highest relative crystallinity (32.25%) and the temperature of the glass transition (58.20 °C). FT-IR revealed that the oil was well encapsulated in the microcapsules. SEM of microcapsules showed spherical shapes without any apparent cracking on the surfaces. During the oxidative stability study, carbohydrate-based microencapsulation was the wall material that best protected the active materials against lipid oxidation.

Assessment of oxidative stability and physicochemical, microbiological, and sensory properties of beef patties formulated with baobab seed (Adansonia digitata) extract.

The present study was conducted to evaluate the oxidative stability and the physicochemical, microbiological, and sensory properties of beef patties formulated with different concentrations (1%, 2%, and 3%) of baobab seed extract (BSE) during storage at 4 °C. The BSE contained a considerable number of phenolic compounds and exhibited antioxidant and antimicrobial activities (both on gram-positive and negative bacteria). The chemical composition of the patties was not altered by BSE treatment. However, the addition of 2% and 3% BSE improved the lipid stability and enhanced the antioxidant activity of beef patties during storage. Furthermore, the shelf-life of patties formulated with 2% and 3% of BSE increased from 7 days (control group) to 21 days. Moreover, the patties formulated with BSE received overall acceptability in the sensory evaluation. In conclusion, the inclusion of 2% or 3% BSE could be recommended as a natural antioxidant additive in beef patties.

Antioxidant and antihyperlipidemic effects of Ajwa date (Phoenix dactylifera L.) extracts in rats fed a cholesterol-rich diet.

This study investigated the chemical composition, in vivo antioxidant, and antihyperlipidemic potential of Ajwa date polyphenol extract (DPE). Chemical analysis revealed that the Ajwa dates contain substantial amounts of carbohydrates, energy, potassium, iron, polyphenols, and flavonoids. In vivo studies showed that feeding rats with cholesterol-rich diets significantly (p ≤ 0.05) increased their body and liver weights, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), very-low-density lipoprotein cholesterol (VLDL-C), and triglycerides (TG) in plasma and liver, and reduced the high-density lipoprotein cholesterol (HDL-C) content and antioxidant enzyme activities. However, oral administration of 25, 50, and 100 mg DPE/kg body weight to hypercholestrolemic rats, significantly (p ≤ 0.05) reduced their body and liver weights, total hepatic cholesterol, LDL-C, VLDL-C, and triglycerides. Furthermore, treatment with DPE improved (p ≤ 0.05) the HDL-C concentration and antioxidant enzyme activity in a concentration-dependent fashion, thereby regulating lipid profiles, enhancing the antioxidant defense system. Overall, DPE showed significant (p ≤ 0.05) nutritional, antioxidants, and antihyperlipidemic benefits. PRACTICAL APPLICATIONS: Coronary heart disease is the leading cause of death in the world. Consumption of fruits and vegetables rich in polyphenol have shown to exert cardio-protective effect. This work revealed that phenolic extracts of Ajwa dates have positive impacts on the health as it reduced TC, LDL-C, and lipids VLDL-C and improved HDL-C and the antioxidant defense system in rats. The findings of this study could aid in the profound understanding of the nutritional and health potentials of Ajwa dates and thus could help in utilization of these valuable fruits for the prevention and curing of cardiovascular diseases.

Identification of Six Phytochemical Compounds from Asparagus officinalis L. Root Cultivars from New Zealand and China Using UAE-SPE-UPLC-MS/MS: Effects of Extracts on H2O2-Induced Oxidative Stress.

A simple, rapid, specific, and sensitive method was developed for the simultaneous identification and quantification of six major bioactive compounds, namely, caffeic acid, quercetin, apigenin, ferulic acid, baicalein, and kaempferol, from Asparagus officinalis roots (ARs) native to New Zealand (green and purple cultivars) and China (yellow, green, purple, and white cultivars) using ultrasound-assisted, solid-phase extraction (UASE-SPE) coupled with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy (expressed as recovery %), and precision (expressed as relative standard deviation (%RSD)). The retention times, ultraviolet visible (UV-vis) data, and mass spectral patterns of the detected peaks matched those of commercial standards, allowing characterization of the target compounds. The LODs and LOQs were 23 ng/mL and 70 ng/mL, 50 ng/mL and 150 ng/mL, 10 ng/mL and 30 ng/mL, 18 ng/mL and 54 ng/mL, 14.4 ng/mL and 43.6 ng/mL, and 7.5 ng/mL and 22.5 ng/mL for caffeic acid, quercetin, apigenin, ferulic acid, baicalein, and kaempferol, respectively, and the mean recovery rates were 85.8%, 73.0%, 90.2%, 80.6%, 76.7%, and 74.5% for the six compounds, respectively. The levels of the target compounds were significantly different (p < 0.05) among the six cultivars. The Chinese yellow AR had the highest levels of bioactive compounds: 6.0, 3.9, 0.4, 1.0, 0.86, and 0.8 mg/g for caffeic acid, quercetin, apigenin, ferulic acid, baicalein, and kaempferol, respectively. The AR extracts showed protective effects against oxidative stress in the HepG2 and L929 cell lines. The results indicate that AR extracts contain high flavonoid levels that provide protective functions against oxidative stress and support the potential commercial application of AR extracts.

Effect of different microwave power setting on quality of chia seed oil obtained in a cold press.

This study was conducted to investigate the impacts of microwave heating treatments at different powers (0, 180, 360, 540, 720 and 900Watts) on the quality attributes of chia seed oil. Linoleic acid contents of the chia seed oil heated in microwave oven changed between 19.21% (900 W) and 21.17% (control), respectively (p < 0.05). Linolenic acid contents of heated chia seed oils varied between 66.84% (900 W) and 68.71% (control). α-Tocopherol and ß-tocopherol contents of the chia oil samples varied between 47.71 mg/100 g (900 W) and 51.17 mg/100 g (control) to 62.58 mg/100 g (900 W) and 67.81 mg/100 g (control), respectively. While caffeic acid contents of the oils change between 0.27 mg/g (900 W) and 3.84 mg/g (control), rosmarinic acid contents of chia seed oils were found between 1.32 mg/g (900 W) and 3.17 mg/g (control). Results reflect a change in the chemical structures of the chia oil. Overall, much care should be taken when roasting chia seeds in microwave to avoid lossess in the bioactive components of chia oil.

Effect of radio frequency heat treatment on protein profile and functional properties of maize grain.

The study was aimed at investigating the effect of radio frequency (RF) heating at different temperatures on the protein profile and functional properties of maize grains. Maize grains with 14% moisture content exposed to the radio frequency energy at 300 W for different temperatures 50, 55 and 60 °C, respectively. The results indicated that radio frequency heating had no effect on the protein profile of maize. The molecular weight distribution of protein remained in the range of 20-25 kDa after RF heating. On the other hand, the functional properties in term of oil holding capacity and emulsifying properties of maize were improved after RF heating. According to these finding, it can be concluded that radio frequency heating improves the functional properties of maize flour. Thus, RF may provide a potential as an effective emerging technology for improving the quality characteristics of maize grains.

Thermosonication process for optimal functional properties in carrot juice containing orange peel and pulp extracts.

Aqueous extracts of orange peel and pulp with high total phenolic contents (TPC) (25.94 and 11.38 mg GAE/g extracts, respectively) were employed in the formulation of functional carrot juice and functional juices were treated using thermosonication process. In accordance with Box-Behnken design, 17 runs with 3 variables and 3 levels was applied for the optimization of the carrot juice with peel (CJPL) and pulp (CJPP) extracts. Overlaid contour plots prediction showed that the optimal conditions for CJPL were 125 mL juice volume, 6.50 min ultrasound process time and 52.78 °C ultrasound process temperature for maximum TPC (30.25 mg GAE/100 mL) and DPPH scavenging activity (61.22%). Sample CJPP has maximum TPC (28.94 mg GAE/100 mL) and DPPH activity (55.87%) under optimal ultrasound process conditions of 125 mL juice volume, 5.04 min and 59.99 °C ultrasound process time and temperature, respectively. Optimization of thermosonication showed significant improvements in the quality of functional carrot juice.

Dubiumin, a chymotrypsin-like serine protease from the seeds of Solanum dubium Fresen.

A serine protease was purified 6.7-fold and with 35% recovery from the seeds Solanum dubium Fresen by a simple purification procedure that combined ammonium sulfate fractionation, cation exchange and gel filtration chromatographies. The enzyme, named dubiumin, has a molecular mass of 66kDa as estimated by gel filtration and SDS-PAGE. Carbohydrate staining established the existence of a carbohydrate moiety attached to the enzyme. Inhibition of enzyme activity by serine protease inhibitors such as PMSF and chymostatin indicated that the enzyme belongs to the chymotrypsin-like serine protease class. Dubiumin is a basic protein with pI value of 9.3, acts optimally at pH 11.0, and is stable over a wide range of pH (3.0-12.0). The enzyme is also thermostable retaining complete activity at 60 degrees C after 1h and acts optimally at 70 degrees C for 30 min. Furthermore, it is highly stable in the presence of various denaturants (2.0% SDS, 7.0M urea and 3.0M guanidine hydrochloride) and organic solvents [CH(3)CN-H(2)O (1:1, v/v) and MeOH-H(2)O (1:1, v/v)] when incubated for 1h. The enzyme showed a high resistance to autodigestion even at low concentrations.