Effect of extraction conditions on lycopene extractions from tomato processing waste skin using response surface methodology

Skin, rich in lycopene, is an important component of waste originating from tomato paste manufacturing plants. A central composite design with five independent variables, namely solvent/meal ratio (20:1, 30:1, 40:1, 50:1, and 60:1 v/w); number of extractions (1, 2, 3, 4 and 5); temperature (20, 30, 40, 50 and 60 °C); particle size (0.05, 0.15, 0.25, 0.35 and 0.43 mm); extraction time (4, 8, 12, 16 and 20 min) was used to study their effects on lycopene extraction. The experimental values of lycopene ranged between 0.639 and 1.98 mg/100 g. The second order model obtained for extracted lycopene revealed a coefficient of determination (R²) of 0.99 and a standard error of 0.03. Maximum lycopene (1.98 mg/100 g) was extracted when the solvent/meal ratio, number of extractions, temperature, particle size and extraction time were 30:1 v/w, 4, 50 °C, 0.15 mm and 8 min, respectively.     

Optimization of phenolics and dietary fibre extraction from date seeds

This work was conducted to optimise extraction conditions of phenolics and dietary fibre from date seeds. The effects of solvent to sample ratio, temperature, extraction time, number of extractions and solvent type on phenolic extraction efficiency were studied. At two-stage extraction, each stage 1 h duration at 45 °C with a solvent to sample ratio of 60:1, is considered optimum. Acetone (50%), and butanone were the most efficient solvents for extraction and purification, increasing the yield and phenolic contents of seed concentrate to 18.10 and 36.26 g/100 g, respectively. The total dietary fibre of seeds (57.87 g/100 g) increased after water and acetone extractions to 83.50 and 82.17 g/100 g, respectively. Nine phenolic acids (free and liberated) were detected in seeds with p-hydroxybenzoic (9.89 mg/100 g), protocatechuic (8.84 mg/100 g), and m-coumaric (8.42 mg/100 g) acids found to be among the highest. After extraction and purification, total phenolic acid content increased significantly from 48.64 to 193.83 mg/100 g. Protocatechuic, caffeic and ferulic acids were the major phenolic acids found in the concentrates. Based on this study, we believe date seed concentrates could potentially be an inexpensive source of natural dietary fibre and antioxidants and possibly used as a functional food ingredient.     

Effect of extraction conditions on the quality characteristics of pectin from passion fruit peel (Passiflora edulis f. flavicarpa L.)

Passion fruit (Passiflora edulis f. flavicarpa L.) yellow variety is composed of 50-55 g peel per 100 g of fresh fruit which is discarded as waste during processing. Utilization of passion fruit peel for pectin extraction was studied. Passion fruit peel obtained after juice extraction was blanched in boiling water for 5 min, dehydrated in a cross flow hot air drier at 60 ± 1 °C to a moisture content of 4 g/100 g of dried peel. The dehydrated passion fruit peel was used for extraction experiments of pectin. The effect of pH, peel to extractant ratio, and number of extractions, extraction time and temperature on the yield and quality characteristics of pectin were investigated. The optimized conditions for extraction of pectin from passion fruit peel yielded 14.8 g/100 g of dried peel. Pectin extracted from the dried peels had a methoxyl content of 9.6 g/100 g, galacturonic acid content of 88.2 g/100 g and jelly grade of 200. Extraction of pectin from dried peels of passion fruit may be considered for effective utilization of passion fruit processing waste.     

Extraction of Cuminum cyminum essential oil by combination technology of organic solvent with low boiling point and steam distillation

Extraction of essential oil from Cuminum cyminum seeds using a combination of organic solvent with low boiling point and steam distillation was explored. The effect of different parameters, such as particle size (40, 60, 80 mesh), temperature (°C) 10, 15, 20 and extraction time (3, 5, 8 h), on the extraction yield was investigated using three-level orthogonal array design. The experimental results showed that the temperature had the largest effect on the yield of the extract (oleoresin), followed by extraction time and particle size. The optimum parameters, such as temperature, particle size, and extraction time were in turn 20 °C, 80 mesh, and 8 h. Essential oil of C. cyminum seeds obtained by supercritical fluid extraction (SFE), hydrodistillation (HD), combination technology of organic solvent with low boiling point and steam distillation (OS-SD) were further analysed by gas chromatographic/mass spectrometric detection to compare the extraction methods. Forty-five compounds in the C. cyminum essential oil were identified, showing that the composition of the extraction by different methods was mostly similar, whereas relative concentration of the identified compounds was apparently different. General characteristics of the C. cyminum essential oil obtained by different methods were further compared, and OS-SD was considered as the optimum process among the three processes to obtain C. cyminum essential oil for high quality, simple technology and low cost.     

Extraction of canola seed (Brassica napus) oil using compressed propane and supercritical carbon dioxide

This study aimed to investigate the extraction of canola seed (Brassica napus) oil using supercritical carbon dioxide and compressed propane as solvents. The extractions were performed in a laboratory scale unit at temperatures and pressures of 40, 50 and 60 °C and 20, 22.5 and 25 MPa for carbon dioxide and 30, 45 and 60 °C and 8, 10 and 12 MPa for propane extractions, respectively. The results indicated that pressure and temperature were important variables for the CO₂ extraction, while temperature is the most important variable for the extraction yield with propane. The extraction with propane was much faster than that with carbon dioxide. The characteristics of the extracted oil, that is, the oxidative stability determined by DSC and the chemical profile of fatty acids determined by gas chromatography, were similar for the two solvents. The overall extraction curves were well described by the Sovová model.     

Chemical and economic evaluation of natural antioxidant extracts obtained by ultrasound-assisted and agitated bed extraction from jussara pulp (Euterpe edulis)

This work aimed to evaluate the influence of ultrasonic and agitated bed extractions on the chemical composition and manufacturing costs of extracts obtained from jussara (Euterpe edulis) pulp. The effects of extraction time (5–180 min), temperature (25–55 °C), ethanol concentration (0–90% in acidified water) and solvent/pulp ratio (5–30 mL/g) on the extraction yield, phenolic content, anthocyanin content, antioxidant capacity and manufacturing costs were assessed. The yields provided by the ultrasound-assisted and agitated bed extractions were not significantly different. The anthocyanins and phenolic compound yields were significantly affected by the extraction time, the ethanol concentration in water and the solvent/feed ratio, but not by the temperature. In general, the antioxidant capacity of the extracts displayed tendencies similar to the anthocyanin and phenolic compound yields. The production of crude extracts obtained by ultrasound and agitated bed extraction incurred greater manufacturing costs compared to the market prices of assai extracts.     

Effects of supercritical fluid extraction parameters on lycopene yield and antioxidant activity

The effects of various parameters of supercritical carbon dioxide (SC-CO₂) fluid extractions of tomato skins on the extraction yields and antioxidant activities of lycopene-rich extracts were investigated. A Box–Behnken design was applied to study the effects of three independent variables (temperature ranging from 40 to 100 °C, pressure ranging from 20 to 40 MPa, and flow rate ranging from 1.0 to 2.0 mL/min) on lycopene yield. The model showed good agreement with the experimental results, by the coefficient of determination (r² = 0.9834). Temperature, pressure, and the quadratic term for the temperature of SC-CO₂ extraction were large significantly positive factors affecting lycopene yield (P < 0.05). The maximum total lycopene content of 31.25 μg/g of raw tomato was extracted at the highest temperature of 100 °C, 40 MPa and 1.5 mL/min. TEAC assay was applied to assess the antioxidant activity of lycopene-rich extracts from SC-CO₂ fluid extraction. The effects of SC-CO₂ fluid extraction parameters on the antioxidant activities of the extracts differed with the yield. For each unit of lycopene extract, the antioxidant activity level was constant below 70 °C, but then gradually decreased above 70 °C due to isomerization occurring as a result of the higher temperature. The ratio of all-trans-lycopene to the cis-isomers changed from 1.70 to 1.32 when the operating temperature was adjusted from 40 to 100 °C, indicating an increased bioavailability due to the generation of the cis-isomers. No significant effects of pressure or flow rate of SC-CO₂ fluid extraction on the antioxidant activity were observed.     

Supercriticial fluid extraction of flavors and fragrances from Hyssopus officinalis L. cultivated in Iran

Hyssopus officinalis L. (hyssop) as a food ingredient has its own importance in flavor industry and also in sauce formulations. Supercritical fluid extraction (SFE) of hyssop, cultivated in Iran, was performed at various pressures, temperatures, extraction (dynamic and static) times and modifier (methanol) concentrations using an orthogonal array design with an OA₂₅(5⁵) matrix conditions. Pressure, temperature and modifier in the SFE system influenced the extraction yield. Also, the composition of the extracted oils was greatly impacted by the operating conditions. Main components of the extracts under different SFE conditions were sabinene (4.2–17.1%, w/w), iso-pinocamphene (0.9–16.5%) and pinocamphene (0.7–13.6%). The extraction of sabinene, for example, was favored at 100 atm, 55 °C, 1.5% (v/v) methanol, 30 min dynamic time and 35 min static time. Use of SFE under different conditions can allow targeting the extraction of different constituents.     

Optimization of carotenoids extraction from Rhodobacter sphaeroides

The comparison of the three methods ultrasonic assisting, grinding and HCl assisting on carotenoids extraction yield from Rhodobacter sphaeroides (R. sphaeroides) was carried out. The HCl-assisted extraction was found to be the most effective. And then, based on HCl-assisted extraction method, the effect of temperature, solvent-solid ratio and duration on the yield of carotenoids extracted from R. sphaeroides was investigated using single factor and Box-Behnken experimental design. The optimal conditions for HCl-assisted extraction of carotenoids from R. sphaeroides were found to be: temperature 30 °C, solvent-solid ratio 40 ml/g, duration 40 min. The first two extractions were enough to approximately exhaust the entire content of carotenoids in R. sphaeroides.     

Chemical compositions and some physical properties of the water and alkali-extracted mucilage from the young fronds of Asplenium australasicum (J. Sm.) Hook

Effect of extraction conditions, including solvent types (water and sodium bicarbonate) and extraction temperatures (25, 50, 70 and 90 °C), on the physicochemical properties of the water and alkali-extracted mucilage from the young fronds of Asplenium australasicum (J. Sm.) Hook was evaluated. It was found that sodium bicarbonate extract generally showed higher yield than water extract, and its yield increased with increasing extraction temperature. Composition analysis revealed that A. australasicum mucilage was composed of mainly carbohydrates in conjunction with some glycoproteins. The weight average molecular size of the carbohydrate fraction of crude mucilage obtained from alkali and water extractions were about 6.30 × 10⁷ and 2.63 × 10⁷, respectively. Sugar composition analysis revealed that A. australasicum young fronds mucilage contained significant amount of uronic acid (14.3-56.6% based on total sugars). For the water extracted mucilage, GlcA is predominant. However, for the sodium bicarbonate extracted mucilage, GalA is predominant. Furthermore, Rha can only be detected in sodium bicarbonate extract. Other major neutral sugars include Gal, Man, Xyl and Fuc. The intrinsic viscosity of the water and alkali-extracted mucilage in deionized water were around 21.12 and 5.92 dL/g, respectively. This information would be useful when considering A. australasicum young fronds mucilage as a new Agro-ingredient.     

Fast method for multielemental analysis of plants and discrimination according to the anatomical part by total reflection X-ray fluorescence spectrometry

Fast and reliable analytical methodologies are required for quality control of plants in order to assure human health. Ultrasound-assisted extraction in combination with total reflection X-ray fluorescence is proposed as a fast and simple method for multielemental analysis of plants on a routine basis. For this purpose, five certified reference materials have been analysed for the determination of P, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn and Pb. Different extractant media (acids and oxidants) were tried. A mixture of diluted HNO₃ + HCl + HF, was selected as the best option for the achievement of complete extractions. Accurate and precise results can be reached in most cases along with a high sample throughput. Different plants (i.e., herbs, spices and medicinal plants) were analysed. Linear discriminant analysis together with the elemental concentrations allowed the differentiation of commercial preparations corresponding to flower, fruit and leaf.     

Optimizing conditions for anthocyanins extraction from purple sweet potato using response surface methodology (RSM)

Optimization for purple sweet potato (Ipomoea batatas (L.) Lam) anthocyanins (PSPAs) extraction was investigated using response surface methodology in this paper. PSPAs were extracted using acid-ethanol at different extraction temperature (40-80 °C), time (60-120 min) and solid-liquid ratio (1:15-1:30). The combined effects of extraction conditions on PSPAs yield and color attributes (expressed as L*, C* and H) were studied using a three-level three-factor Box-Behnken design. The results showed that The highest yield (158 mg/100 g dw) of PSPAs were reached at the temperature 80 °C, extraction time 60 min, and solid-liquid ratio 1:32. PSPAs yield indicated a high and significant correlation with L^* (P<0.05; r=−0.961) and it was significantly affected by extraction temperature (P<0.01) and solid-liquid ratio (P<0.05).     

Proximate composition and extraction of carotenoids and lipids from Brazilian redspotted shrimp waste (Farfantepenaeus paulensis)

The chemical composition of redspotted shrimp (Penaeus paulensis) waste was investigated. The shrimp waste (freeze-dried heads, shells and tails) was found to have high protein (49% d.w.) and ash (27% d.w.) contents, but a low lipid content (4.9% d.w.) although the latter was higher than those found in other kinds of shrimp captured in Brazil. The fatty acid compositions showed that the lipids had a high content of unsaturated fatty acids, mainly EPA (C20:5; n-3) and DHA (C22:6; n-3). In order to establish an efficient and environmentally friendly recovery process for the astaxanthin (principal carotenoid and antioxidant present in the waste), the following processes were examined: traditional solvent extraction (TSE), super-critical fluid extraction (SC-CO₂) and super-critical fluid extraction with co-solvent (SC-CO₂ + ethanol). The temperature and pressure conditions for all the SC-CO₂ extractions were 50 °C and 30.0 MPa. The results showed that the mixture of 60% (v/v) n-hexane:isopropyl alcohol gave the highest (53 mg/kg waste) carotenoid extraction yield as compared to acetone, SC-CO₂ and SC-CO₂ + ethanol. The SC-CO₂ showed the lowest extraction yield of astaxanthin, but the addition of the entrainer (10% w/w) produced an important effect, increasing the astaxanthin extraction to values of 57.9%, similar to extraction with acetone (63.3%).     

Short communication: effect of number of extractions on percentage of long-chain fatty acids from fresh alfalfa

Accurate determination of fatty acids in fresh forage is very important when studying biohydrogenation. Fatty acids from fresh alfalfa were extracted by hexane:isopropanol (H:IP, 3:2 vol.vol) in 3 sequential extractions. The percentage and profile of fatty acids from each of the 3 extractions were evaluated by a randomized complete block design with repeated measures in space. Samples of fresh alfalfa were randomly harvested and immediately submerged in liquid nitrogen. For the first extraction, approximately 5 g of the frozen alfalfa was mixed with 18 mL of H:IP per gram of material. Samples were then centrifuged and the supernatant was collected. The second and third extractions were done by adding H:IP to the pellet (3 mL/g of the original sample weight), mixing for 2 min, and then centrifuging. Samples were submerged in H:IP and stored in the dark at 8°C at all times. The solvent from each extraction was partially evaporated and the fatty acids methylated by methanolic HCl. Repeated extractions increased the percentage of total fatty acids recovered from the samples. The concentration of fatty acids in the alfalfa after 3 extractions was 4.0%. The first, second, and third extractions resulted in 92.7, 4.8, and 2.6% of the total fatty acids extracted, respectively. There was no effect of extraction on the proportion of 16:0, 18:0, 18:1, and 18:2 fatty acids. However, the proportion of 18:3 in the extract decreased from the first to the second extraction and the ratio of saturated to unsaturated fatty acid increased from the first to the second extraction. The results of this experiment revealed that the profile of fatty acids can vary with the number of extractions performed. The higher amount of 18:3 in the first extraction may reflect the higher proportion of linolenic acid in the more easily extracted plant fractions.     

Improved extraction of oil from chickpea under ultrasound in a dynamic system

In this work, ultrasound-assisted dynamic extraction (UADE) is proposed. The dynamic approach allows go-and-backward circulation of solvent through the sample subjected to the action of ultrasound. The extraction efficiency of hexane, isopropanol, a hexane–isopropanol mixture as well as the comparison between static extraction and flow-through extraction with or without ultrasound were evaluated. The effects of ultrasonic power, extraction temperature, time and extractant flow rate on the yield of oil from chickpea were also investigated. Results showed that solvent type significantly influenced extraction efficiency, the combination of hexane and isopropanol obtained the highest oil yield. Dynamic system and ultrasonication dramatically enhanced the extraction of oil. Moreover, results indicated that 20 min was sufficient for UADE with lower cost to obtain higher extraction yields (10.45% and 2.06% higher) than those by 4 h conventional solvent extraction (CSE) and 30 min ultrasound-assisted extraction (UAE) for oil. Gas chromatography analysis of chickpea oil indicated that the oil was enriched with polyunsaturated fatty acids and few changes in fatty acid composition occurred in ultrasonicated oil.     

The influence of different acids and pepsin on the extractability of collagen from the skin of Baltic cod (Gadus morhua)

Solutions of (0.5 M) citric, lactic and acetic acids and 0.15 M HCl were used for the extraction of collagen from the whole skins of Baltic cod (Gadus morhua). The extractions were performed at a temperature of 4 °C for 24, 48 and 72 h using a solid/solution ratio of 1:6 (w/v). Of the acids used, HCl was the least effective solvent for collagen. The maximal yield of collagen extracted with citric acid was 60%. Collagen extraction with acetic or lactic acid give a maximal yield of about 90% with HCl yielding of only 18%. After enzymatic treatment of cod skin the yield of protein extracted with HCl and citric acids increased to 40% and 20%, respectively. Collagen was completely solubilized under the same conditions in acetic and lactic acids. Electrophoretic analysis of collagens extracted in HCl and citric acids with enzymatic treatment proved that the isolated protein was denaturated. The solutions of acetic and lactic acids are solvents for native collagen.     

Optimization of Factors Affecting Extraction of Antioxidants from Mango Seed

A microwave-assisted extraction procedure was developed to obtain extracts rich in antioxidants from mango seed. Central composite design ‘2⁵?+?star’ and response surface methodology were used in order to optimise the extraction factors: the water content in the acetone/water mixture used as extractant, seed weight-to-solvent volume ratio, number of steps, extraction time and pH of water. The results suggest that the extractant composition and the seed weight-to-solvent volume ratio were statistically the most significant factors. The optimum values of the factors that influence the capacity to inhibit lipid peroxidation (evaluated with the β-carotene bleaching test), scavenge 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid-free radicals and obtain extracts with high phenolic compound content (tannins and proanthocyanidins) were three steps; the mixture acetone/water (50:50, v/v) as extractant, a seed weight-to-solvent volume ratio of 1:30 (w/v), an extraction time of 0 min in the microwave (the rest of the extraction process includes homogenisation and centrifugation time), and a pH of 8.0.     

Characterisation of pectins extracted from banana peels (Musa AAA) under different conditions using an experimental design

An experimental design was used to study the influence of pH (1.5 and 2.0), temperature (80 and 90 °C) and time (1 and 4 h) on extraction of pectin from banana peels (Musa AAA). Yield of extracted pectins, their composition (neutral sugars, galacturonic acid, and degree of esterification) and some macromolecular characteristics (average molecular weight, intrinsic viscosity) were determined. It was found that extraction pH was the most important parameter influencing yield and pectin chemical composition. Lower pH values negatively affected the galacturonic acid content of pectin, but increased the pectin yield. The values of degree of methylation decreased significantly with increasing temperature and time of extraction. The average molecular weight ranged widely from 87 to 248 kDa and was mainly influenced by pH and extraction time.     

Supercritical fluid extraction in situ derivatization for simultaneous determination of chloramphenicol,florfenicol and thiamphenicol in shrimp

The applicability of supercritical fluid extraction in situ derivatization was investigated for determination of trace amounts of amphenicols (chloramphenicol, florfenicol and thiamphenicol) in shrimp. Quantification was performed by using electron-capture negative chemical ionisation-gas chromatography/mass spectrometry (NCI–GC/MS). The parameters of supercritical fluid extraction (addition of modifier, temperature, pressure, extraction time and extraction mode) and in situ derivatization (collection solvent and derivatization reagent) were varied with control. The optimum extractions were obtained using 600 μL ethyl acetate as a modifier for supercritical carbon dioxide with static extraction for 5 min, then dynamic extraction for 10 min at 25 MPa and 60 °C. The conditions for in situ derivatization were 200 μL N,O-bis(trimethylsilyl) trifluoroacetamide containing 1% trimethylchlorosilane in 20 mL ethyl acetate as collection solvent. The new method of supercritical fluid extraction in situ derivatization was found to be linear over the concentration range of 20–5000 pg/g, with detection limits ranging from 8.7 to 17.4 pg/g (using the selective ion monitoring mode), with a R.S.D. (relative standard deviation) less than 15.3% (n = 5). Analysis of spiked shrimp samples revealed that matrix had little effect on extraction. The results presented here indicate that supercritical fluid extraction in situ derivatization is for the trace analysis of amphenicol bacteriostats in shrimp samples.     

Validation of a HPLC method for simultaneous determination of main organic acids in fruits and juices

A liquid chromatographic method for fast and simultaneous determination of tartaric, malic, ascorbic and citric acids was validated for further application to fruits and juices. Moreover, the organic acids content of commercial samples of fruits and juices were evaluated, as well as the ascorbic acid stability during the storage. Determination of organic acids was carried out using a liquid chromatograph coupled to a diode array detector, with reversed phase (C₁₈ column) and isocratic elution with 0.01 mol L⁻¹ KH₂PO₄ (pH = 2.60) mobile phase. The validation parameters showed efficiency, adequate linearity, relative standard deviation values between 0.4% and 2.3% (n = 10) for repeatability and from 1.2% to 5.0% (n = 18) for reproducibility, limits of detection (LD) were between 0.03 and 3.31 μg mL⁻¹ and quantification (LQ) were between 0.10 and 11.03 μg mL⁻¹, recovery rates were between 82% and 110%, for two levels. In addition, the method is fast (10 min) and generates low and non-toxic residues. The values found for vitamin C were about 10 times above the values declared at the package. Ready to drink juices have a composition similar to the fruit, concerning to organic acids, except for the powder juice, in which only ascorbic and citric acids were found, for all tastes. After opening the package, a decrease of 14.0% and 27.0% in ascorbic acid content was observed for orange powder and ready to drink juices, respectively.