Comparison of the compounds and characteristics of pepper seed oil by pressure-assisted, ultrasound-assisted and conventional solvent extraction

Ultrasound-assisted reverse micelle extraction and characterization of tea protein from tea residue

BACKGROUND

In this study, ultrasonic-assisted reverse micelles were used to extract tea protein from tea residues. First, the extraction conditions of ultrasonic power, ionic strength and pH were optimized by response surface methodology. Then, structural comparison of ultrasonic-assisted reverse micelle extraction of tea protein (UARME) and ultrasonic-assisted alkali extraction (UAAE) were performed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and amino acid composition.

RESULTS

The optimum process conditions were determined as follows: ultrasonic power 300 W, KCl 0.15 mol L^-1 , pH 8. The extraction rate was 46.29%, which was close to the theoretical value (46.44%). SEM showed that the protein particles extracted by UARME were smaller than those by UAAE. The results of FTIR spectroscopy showed that the protein extracted by UARME had higher α-helix, β-sheet and β-turn, and the contents were 20%, 62.3% and 17.1%, respectively. The content of random coil was 0%, which was significantly lower than that of alkali extraction, indicating that the secondary structure of protein extracted by UARME was more orderly. By comparing the amino acid composition of the two methods, the amino acid content of tea protein extracted by UARME was significantly higher than that of UAAE.

CONCLUSION

The biological activity of tea protein is closely related to its structure. Compared with alkali extraction, reverse micelles can better protect the secondary structure of proteins, which is of great significance for studying their functional properties. © 2022 Society of Chemical Industry.

A review on application of ultrasound and ultrasound assisted technology for seed oil extraction

Oil has extensively been extracted from oil-bearing crops and traded globally as a major food commodity. There is always a huge demand from the fats and oils industries to increase oil yield because of profitability benefits. If extraction is conducted under mild operating conditions to preserve and improve the oil quality, then it would be an added value. Ultrasound that works on the cavitational action helps to fulfil the gap. Ultrasound is gaining tremendous interest as an alternative to replace the current conventional extractions approach because of its multiple benefits. Cavitation generated by ultrasound eases the release of oil from cell matrices, thereby allowing the extraction to be carried out under mild processing conditions. The effect enhances the oil yield whilst preserving the quality of the oil. In ultrasound, green solvents can be used to replace toxic organic solvents. Recent up-to-date approaches utilised a combination of ultrasound with enzyme, microwave and supercritical technology to further enhance the oil extraction. This review highlights a comprehensive work of the impact of ultrasound and ultrasound in combination with other technologies on oil extraction, which emphasises the extraction yield and physicochemical properties of the oil, such as fatty acid composition, oxidative stability with the retention of the lipophilic phytochemicals and iodine, saponification values and colour parameters. Understanding of ultrasonication techniques for oil extraction served to be essential and useful information for the fats and oils scientists from academia and industries to explore the possibility of employing a sustainable and mild approaches for extracting oil from various crops.

Ganodiesel: A New Biodiesel Feedstock from Biomass of the Mushroom Ganoderma lucidum

There is a pressing demand for new sustainable eco-friendly approaches to producing green energy worldwide. This study represents the novel production of biodiesel feedstock from the medicinal mushroom Ganoderma lucidum QRS 5120 using state-of-the-art biotechnology tools. Response surface methodology (RSM) was used to enhance G. lucidum production in a repeated-batch fermentation strategy. By referring to the broth replacement ratio (BRR) and broth replacement time point (BRTP), RSM that was formulated using a central composite design (CCD) resulted in a significant model for all tested variables, which are exopolysaccharide (EPS), endopolysaccharide (ENS) and biomass, with BRR (%) of 60, 75 and 90, and BRTP (days) of 11, 13 and 15. The model was validated using the optimised conditions, and the results showed 4.21 g/L of EPS (BRR 77.46% and BRTP 12 days), 2.44 g/L of ENS (BRR 60% and BRTP 12.85 days), and 34.32 g/L of biomass (BRR 89.52% and BRTP 10.96 days) were produced. Biomass produced from the G. lucidum was subsequently used as feedstock for biodiesel production. Approximately 20.36% of lipid was successfully extracted from the dried G. lucidum biomass via a solvent extraction and subsequently converted to Ganodiesel through a transesterification process. The Ganodiesel produced fulfilled most of the international standards, i.e., US (ASTM D6751-08) and EU (EN 14214). Overall, this study demonstrates the optimised G. lucidum production and its lipid production as a new biodiesel feedstock.

Anthocyanin Extraction from Jaboticaba Skin (Myrciaria cauliflora Berg.) Using Conventional and Non-Conventional Methods

This study evaluated the effect of different extraction technologies and conditions in order to obtain jaboticaba skin extracts. Firstly, the skins were extracted by conventional extraction, according to a rotatable central composite design, varying ethanol concentration, solid:liquid ratio, and temperature. Next, ultrasound-assisted extraction was performed using different power densities and times. Finally, high-pressure extractions were performed with varying pressures and times. For agitated bed extraction, the highest anthocyanin content was observed for ethanol concentrations varying between 60% and 80%. Thus, the independent variables which more influenced anthocyanin content were ethanol concentration and solid:liquid ratio. Folin–Ciocalteu reducing capacity was linearly affected by the increase in temperature. Ethanol concentration was the variable that most influenced ABTS+. On the other hand, the increase in ethanol concentration decreased the antioxidant capacity by ABTS+. Considering the ultrasound extraction, increasing its power did not affect total monomeric anthocyanins content, while the increase in process time had better yields. The highest antioxidant capacity and total monomeric anthocyanins were found for the highest extraction time. Similarly, with ultrasound, the increase in high hydrostatic-assisted extraction time positively influenced anthocyanin content and antioxidant capacity. As a result, the ultrasound-assisted method was found to be the best extraction technology for anthocyanins recovery.

Evaluation of Phenolic Compounds and Pigments Content in Yellow Bell Pepper Wastes

Bell peppers are one of the most important species consumed and cultivated in Spain. Peppers are a source of carotenoids and phenolic compounds widely associated with biological activities such as antimicrobial, antiseptic, anticancer, counterirritant, cardioprotective, appetite stimulator, antioxidant, and immunomodulator. However, undersized and damaged fruits are usually wasted. Thus, in order to evaluate the phenolic content, a Box–Behnken design has been carried out to optimize the extraction from Capsicum annuum yellow pepper by ultrasound-assisted extraction (UAE). The independent factors were time (min), ethanol/water (% v/v) and solvent/sample ratio (v/w). The model was validated by ANOVA and confirmed. Furthermore, the whole pepper and the pepper without peduncles and seeds were extracted using optimal conditions and characterized by HPLC-ESI-TOF-MS. Moreover, their antioxidant activities, measured by three different methods (DPPH, ABTS, and FRAP), carotenoid composition, assessed by HPLC-MS, and chlorophyll content, assessed by a spectrophotometric method, were compared. A total of 38 polar compounds were found of which seven have been identified in pepper fruit extracts for the first time. According to the results, whole pepper (WP) samples presented higher content in phenolic acids; meanwhile, the edible portion (EP) was higher in flavonoids. No differences were found in the antioxidant activity except for the FRAP assay where the WP sample showed higher radical scavenging activity. EP samples showed the highest content of carotenoids and WP ones in chlorophylls.

Quality of Pepper Seed By-Products: A Review

Peppers are grown all around the world, usually for fresh consumption, as well as for the industrial production of different products. Pepper (Capsicum annuum L.) seeds are mostly considered a by-product. Recent investigations have shown that pepper seeds have the potential to be a valuable source of edible oil and fiber-rich flour and protein after processing. Pepper seed oil is a high-quality edible oil according to quality analysis (nutritional, chemical, sensory and antioxidant characteristics) and is suitable as an ingredient for use in the food and nonfood industries (pharmaceutical, chemical, cosmetic industries). The literature review presented in this paper revealed the high quality of two pepper seed by-products (pepper seed oil and pepper seed flour (Capsicum annuum L.)), which could guide the food industry toward new product development based on the circular bioeconomy.

The Effect of Different Extraction Methods on Extraction Yield, Physicochemical Properties, and Volatile Compounds from Field Muskmelon Seed Oil

Field muskmelon seed oil was extracted by press extraction (PE), Soxhlet extraction (SE), organic extraction (OSE), and aqueous extraction (AE). The oils were then evaluated for their physicochemical properties, fatty acid composition, volatile compounds, and antioxidant properties. A high yield oil was found in the SE sample. The AE sample had the highest elevated acid and peroxide values, while PE and OSE had the highest oil iodine content. The oil samples did not differ significantly in their fatty acid profile depending on the extraction method. However, E-nose, HS-GC-IMS, and HS-SPME-GC-MS showed that the flavor composition of the four samples was significantly different, attributed to the changes in the composition and content of the compounds caused by the different extraction methods. Furthermore, the strongest FRAP and the free radical scavenging ability of DPPH and ABTS⁺ showed in the SE sample. In general, SE’s seed oil has certain advantages when applied to the muskmelon seed oil industry.

Chemical characterization of Echium plantagineum seed oil obtained by three methods of extraction

Echium seed oil has been considered an important alternative source of omega 3 fatty acids (n-3 FA) for human consumption. Considering the oxidative instability of n-3 FA richer oils, the objective of this study was to determine the chemical and sensory parameters of the oil obtained from Echium plantagineum seeds obtained by three extraction methods (hydraulic press: HYD; continuous screw press: PRESS; and solvent technique: SOLV). Stearidonic acid (C18:4, n3), the most important n-3 FA present in the oil, changed from 12.5% to 12.7%. Regarding the minor compounds, PRESS sample showed the highest concentration of gamma-tocopherol (782.24 mg/kg oil), while SOLV samples presented the highest amount of β-sitosterol (73.46 mg/100 g) with no difference of campesterol concentration (159.56 mg/100 g) among the samples. Higher values of total phenolics (19.65 mg GAE/kg oil) and β-carotene (34.83 mg/kg oil) were also found in the SOLV samples, suggesting the influence of hexane in the extraction of these bioactive compounds. High resolution mass spectrometry identified caffeic acid and its derivatives as the main phenolic compounds present in the echium oil. PRESS sample showed the best oxidative stability as measured by PV (0.61 mmol/kg oil) and malondialdehyde (173.13 µmol), probably due to faster time of processing compared to HYD and SOLV samples. Our data showed that the extraction method changed the chemical composition of the minor compounds in the echium oil, but these alterations did not reduce its nutritional quality or sensory acceptability. PRACTICAL APPLICATION: Echium oil represents a great potential source of omega 3 fatty acids, but there is not enough information about its oxidative stability and chemical composition, especially toward minor compounds. Our study characterizes echium oil composition obtained from three extraction methods, contributing to amplify the technical information about this important alternative oil for human consumption.

Physicochemical properties of seed protein isolates extracted from pepper meal by pressure-assisted and conventional solvent defatting

Pepper seed is one by-product in pepper processing, rich in protein, fat, and fiber, and is a new plant-based protein source. In this paper, the physicochemical and functional properties of pepper seed protein isolates (PSPIs) extracted from pepper meal by pressure-assisted defatting (PAD) and conventional solvent defatting (CSD) were investigated. The yields of SPIs extracted by CSD and PAD were 22.8% and 20.5%, respectively. Compared with the PSPIs obtained by CSD, the solubility, water-holding and oil-holding capacities, and emulsifying and foaming abilities of the PSPIs obtained by PAD were significantly increased by 11.22%, 29.17%, 40%, 160%, and 100%, respectively. Additionally, UV-visible, intrinsic fluorescence and infrared spectroscopic characterization revealed the tertiary and secondary conformation changes of the PSPIs, which might contribute to the improvement of their functional properties. Overall, PAD significantly improved the functional properties of the PSPIs. The PSPIs extracted by this innovative technology would be a new plant protein alternative for food formulations with better functional properties.

Extraction of Peanut Oil Using Thermosonication: Modeling and Multiobjective Optimization of Process Parameters Using Box-Behnken Design

The extraction of peanut oil was investigated using the combination of ultrasound and heat application, which is known as a novel technology called thermosonication. The study was set up using the Box-Behnken design and the models based on quadratic equations were established. The effects of extraction time (4-12 min), extraction temperature (40-60°C), solvent-to-solid ratio (SSR) (3:1-9:1)(v/w) and ultrasound power (60-100%) on the extraction yield and the oleic acid concentration of extracted oils were investigated. Results showed that the extraction yield was primarily affected by the extraction temperature and SSR. The average maximum yield of 39.93% was achieved when variables were set to 12 min of time, 50°C of temperature, 9:1(v/w) of SSR and 80% of ultrasound power. Thermosonication did not significantly affect the fatty acid composition. Since it was targeted to determine an optimum point where the maximum extraction yield and oleic acid concentration were obtained, a multiobjective optimization was performed. The optimum thermosonication conditions were determined as 4 min of time, 60°C of temperature, 9:1(v/w) of SSR and 100% of power with a maximum extraction yield of 39.86%. Also, the oleic acid concentration was determined as 63.51% in this optimum condition.

Extraction of chitosan from squid pen waste by high hydrostatic pressure: Effects on physicochemical properties and antioxidant activities of chitosan

Squid pen sample was treated by high hydrostatic pressure (HHP) prior to the extraction of chitosan. The physicochemical and antioxidant activities of the chitosan obtained with HHP (HHP-CS) were compared with chitosan of untreated squid pen sample (UT-CS). The chitosan extraction yield was optimized using response surface methodology, and the optimum condition was achieved at pressure of 500 MPa, extraction time of 10 min, and 1% (w/w) acetate concentration. The maximum yield of chitosan sample from the chitin of squid pens treated by HHP reached 81.9%. Among the process variables, the combined effects of pressure and acetate concentration significantly enhanced the extraction of chitosan from squid pens. The HHP-CS was found to be significantly effective in enhancing the fat binding capacity, water binding capacity, and water solubility index. SEM image analysis suggested that the HHP-CS had a rough surface with high porosity, while UT-CS exhibited a smooth surface. In vitro antioxidant assay suggested that HHP-CS had significantly higher DPPH radical scavenging activity, greater reducing power, and a stronger ferrous ion chelating effect than did UT-CS. Therefore, HHP can be an excellent alternative method for improving the physicochemical properties and antioxidant activities of chitosan from squid pens.

Ultrasound-Assisted Extraction of Taxifolin, Diosmin, and Quercetin from Abies nephrolepis (Trautv.) Maxim: Kinetic and Thermodynamic Characteristics

Extraction behaviors of the 3 flavonoids taxifolin, diosmin, and quercetin have been investigated in Abies nephrolepis leaves and bark. The following operation parameters—ethanol volume fraction, liquid–solid ratio, temperature, ultrasound irradiation power and time, and ultrasound frequency—were varied to study their effect on the yield of the 3 flavonoids during extraction. The results showed that a low extraction efficiency occurred at 293.15 K due to slow kinetics, while the situation was significantly improved at 333.15 K. The kinetic data for the extraction yields of the 3 flavonoids achieved good fits by the first-order kinetic model. From the thermodynamic analysis results, we realized that the ultrasound-assisted extraction of taxifolin, diosmin, and quercetin from the leaves and bark of A. nephrolepis was a spontaneous and endothermic process in which the disorder increased (ΔG⁰ < 0, ΔH⁰ > 0, and ΔS⁰ > 0). According to the response surface methodology (RSM) analysis, under the optimal operation conditions (ethanol concentration of 50%, liquid–solid ratio of 20 mL/g, frequency of 45 kHz, extraction time of 39.25 min, ultrasound irradiation power of 160 W and temperature of 332.19 K), the total yield of the 3 flavonoids were 100.93 ± 4.01 mg/g from the leaves of A. nephrolepis (with 31.03 ± 1.51 mg/g, 0.31 ± 0.01 mg/g, 69.59 ± 2.57 mg/g for taxifolin, diosmin, and quercetin, respectively), and under the optimal operation conditions (ethanol concentration of 50%, liquid–solid ratio of 20 mL/g, frequency of 45 kHz, extraction time of 36.80 min, ultrasound irradiation power of 150 W and temperature of 328.78 K), 16.05 mg/g ± 0.38 mg/g were obtained from the bark of A. nephrolepis (with 1.44 ± 0.05 mg/g, 0.47 ± 0.01 mg/g, 14.14 ± 0.38 mg/g for taxifolin, diosmin, and quercetin, respectively), which were close to the prediction values.

Optimization of Ultrasound Assisted Extraction (UAE) of Kinsenoside Compound from Anoectochilus roxburghii (Wall.) Lindl by Response Surface Methodology (RSM)

The purpose of this study was to establish an extraction method for the kinsenoside compound from the whole plant Anoectochilus roxburghii. Ultrasound assisted extraction (UAE) and Ultra-high performance liquid chromatography (UPLC) method were used to extract and determine the content of kinsenoside, while response surface method (RSM) was used to optimize the extraction process. The best possible range for methanol concentration (0–100%), the liquid-solid ratio (5:1–30:1 mL/g), ultrasonic power (240–540 W), duration of ultrasound (10–50 min), ultrasonic temperature (10–60 °C), and the number of extractions (1–4) were obtained according to the single factor experiments. Then, using the Box-Behnken design (BBD) of response surface analysis, the optimum extraction conditions were obtained with 16.33% methanol concentration, the liquid-solid ratio of 10.83:1 mL/g and 35.00 °C ultrasonic temperature. Under these conditions, kinsenoside extraction yield reached 32.24% dry weight. The best conditions were applied to determine the kinsenoside content in seven different cultivation ages in Anoectochilus roxburghii.