High Hydrostatic Pressure Extraction Research Articles

Valorisation of Agri-Food Waste for Bioactive Compounds: Recent Trends and Future Sustainable Challenges.

Worldwide, a massive amount of agriculture and food waste is a major threat to the environment, the economy and public health. However, these wastes are important sources of phytochemicals (bioactive), such as polyphenols, carotenoids, carnitine, coenzymes, essential oils and tocopherols, which have antioxidant, antimicrobial and anticarcinogenic properties. Hence, it represents a promising opportunity for the food, agriculture, cosmetics, textiles, energy and pharmaceutical industries to develop cost effective strategies. The value of agri-food wastes has been extracted from various valuable bioactive compounds such as polyphenols, dietary fibre, proteins, lipids, vitamins, carotenoids, organic acids, essential oils and minerals, some of which are found in greater quantities in the discarded parts than in the parts accepted by the market used for different industrial sectors. The value of agri-food wastes and by-products could assure food security, maintain sustainability, efficiently reduce environmental pollution and provide an opportunity to earn additional income for industries. Furthermore, sustainable extraction methodologies like ultrasound-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, microwave-assisted extraction, pulse electric field-assisted extraction, ultrasound microwave-assisted extraction and high hydrostatic pressure extraction are extensively used for the isolation, purification and recovery of various bioactive compounds from agri-food waste, according to a circular economy and sustainable approach. This review also includes some of the critical and sustainable challenges in the valorisation of agri-food wastes and explores innovative eco-friendly methods for extracting bioactive compounds from agri-food wastes, particularly for food applications. The highlights of this review are providing information on the valorisation techniques used for the extraction and recovery of different bioactive compounds from agricultural food wastes, innovative and promising approaches. Additionally, the potential use of these products presents an affordable alternative towards a circular economy and, consequently, sustainability. In this context, the encapsulation process considers the integral and sustainable use of agricultural food waste for bioactive compounds that enhance the properties and quality of functional food.

Sea Buckthorn Flavonoid Extracted by High Hydrostatic Pressure Inhibited IgE-Stimulated Mast Cell Activation through the Mitogen-Activated Protein Kinase Signaling Pathway.

Sea buckthorn (Hippophaë rhamnoides L.), as one of the Elaeagnaceae family, has the significant function of anti-tumor, anti-inflammation, anti-oxidation, and other physiological activities. High hydrostatic pressure (HHP) extraction has the advantages of being easy and efficient, while maintaining biological activity. In this study, sea buckthorn flavonoid (SBF) was extracted with HHP and purified sea buckthorn flavonoid (PSBF) was isolated by AB-8 macroporous resin column. HPLC analysis was used to quantified them. In addition, the effect of anti-allergy in RBL-2H3 cells by SBF, PSBF, and their flavonoid compounds was evaluated. The results demonstrate the conditions for obtaining the maximum flavonoid amount of SBF: 415 MPa for 10 min, 72% ethanol concentration, and a liquid to solid ratio of 40 mL/g, which increased the purity from 1.46% to 13.26%. Both SBF and PSBF included rutin, quercitrin, quercetin, isorhamnetin, and kaempferol. In addition, quercitrin, kaempferol, and SBF could regulate Th1/Th2 cytokine balance. Moreover, extracellular Ca2+ influx was reduced by quercitrin and PSBF. Furthermore, rutin, quercetin, iso-rhamnetin, and SBF could also inhibit P-p38 and P-JNK expression, thereby suppressing the phosphorylation of the MAPK signaling pathways. Overall, SBF is effective for relieving food allergy and might be a promising anti-allergic therapeutic agent.

Optimization of the extraction of phenolic compounds from the leaves of yerba mate (Ilex paraguariensis) through high hydrostatic pressure system using mixture design with process variables.

In this study, a mixture design with process variables was used to optimize the extraction of total phenolic compounds (TPC) from yerba mate leaves through high hydrostatic pressure extraction. The studied variables were pressure (50, 100, and 150 MPa), extraction time (10, 20, and 30 min), and solvent (water, glycerin, and 50% v/v water/50% v/v glycerin). The multiple linear regression model presented an excellent fit (R2 adjusted of 0.9792) and demonstrated the major influence of glycerin content on the water/glycerin mixture solvent for TPC extraction. Optimal process conditions obtained were 69% v/v water, 31% v/v glycerin, 50 MPa pressure, and 10 mintime. PRACTICAL APPLICATION: The paper describes a novel extraction method to obtain phenolic compounds from yerba mate (compounds that can replace synthesized antioxidants in the food industry) using high hydrostatic pressure and environmentally friendly solvents. The extraction process was studied to optimize its performance, obtaining more phenolic compounds from the same amount of yerbamate.

Evaluation of Nonconventional Extraction Methods of Resveratrol from Various Plant Sources - A Brief Review

Abstract: Resveratrol is a stilbene class of phenolic phytochemical that has a wide range of utilization in several industries, including pharmaceutical, food and cosmetic industries. It is available in several plants, including grapes, berries, and peanuts. Major focus of research regarding resveratrol has been its therapeutic potential against major diseases, including cardiovascular, inflammatory, cancer, microbial and age-related diseases. However, its extraction methods have not been of much discussion. In this review, nonconventional methods, including supercritical fluid extraction, subcritical water extraction, microwave-assisted extraction, ultrasound assisted extraction, and high hydrostatic pressure extraction have been discussed in contrast to widely implemented conventional extraction methods. Nonconventional methods are considerably advanced over conventional methods. In this review, the efficiency of various nonconventional methods via optimization of their extraction parameters, such as the effects of modifiers, solvents, pressure, temperature, and extraction time, have been evaluated. Improvised extraction methods may result in cost-effective isolation of resveratrol.

High hydrostatic pressure-assisted extraction of lipids from Lipomyces starkeyi biomass.

The purpose of this study is to evaluate the effect of high hydrostatic pressure (HHP) as a novel approach for yeast cell disruption and lipid extraction from Lipomyces starkeyi DSM 70295 grown in glucose medium (40g/L and C/N:55/1) at initial pH of 5.0, 25°C, and 130rpm for 8 days. HHP extraction conditions including pressure, time, and temperature were optimized by response surface methodology. The high speed homogenizer-assisted extraction (HSH) was also used for comparison. The biomass subjected to HHP was examined under scanning electron microscopy and light microscope. A maximal lipid yield of 45.8±2.1% in dry cell basis (w/w) was achieved at 200MPa, 40°C, and 15min, while a minimum yield of 15.2±0.9% was observed at 300MPa, 40°C, and 10min (p<0.05). The lipid yield decreased with increasing pressure. It was demonstrated that low pressure (200MPa) collapsed the cells, while high pressure (400MPa) created protrusions on the cell wall and cell fragments spread in the environment. This study favors HHP as a promising method for Lipomyces oil extraction. PRACTICAL APPLICATION: Single-cell oils are considered future alternatives to plant-based oils as food additives and dietary supplements. Oleaginous microorganisms accumulate oils in their cell plasma, which makes extraction essential. One of the main obstacles with existing methods is the utilization of strong acids to destroy cell walls. This study aims to demonstrate high hydrostatic pressure as a rapid method for lipid extraction from oleaginous yeast Lipomyces starkeyi.

A Review on the Usage of Main Secondary Metabolites of Crocus sativus in Cancer Treatments

Saffron is the world’s second most costly spice, with numerous advantages of culinary, cosmetics, pharmaceutical and medical fields. There is an inadequate awareness of how Crocus sativus L. (Family Iridaceae) which produces the spice saffron from the filaments that grow inside the flower, can possibly treat cancer. Since, cancers are regarded as a devastating disease in today's world, anticancer and antioxidant properties of secondary metabolites available in saffron will be highly invaluable. The present review focuses on investigating on the role of crocin, crocetin and safranal in cancer treatments, which are the main secondary metabolites of C. sativus, and evaluating the various methods of extracting, isolating and analysing them. The review conducted using subjective indexed journal articles that were published over the past ten years. Out of the available data, it found that crocin would be quite beneficial in healing cancer without revealing any adverse effects. Crocin showed immense potential in curing a wide range of cancer types, mainly prostate and lung cancers, by eliminating cancer cells through apoptosis and inhibiting tumour invasion. There were a limited number of researches conducted using crocetin and safranal. However, they will approve for cancer treatments shortly. Crocetin was widely employed as a chemo-preventive and anti-inflammatory medication for pancreatic and breast cancer treatments. It has recently been utilized only for treatments of few types of cancers. Only one publication recorded in the recent ten years, as the usage of safranal in cancer treatment, which was against leukaemia. Moreover, secondary metabolite analysis techniques including spectrophotometry and chromatography utilized effectively, whereas predominantly improved extraction techniques including ultrasound-assisted extraction, emulsion liquid membrane, high hydrostatic pressure extraction. The analysis affirmed that, microwave[1]assisted extraction (80±1%) followed by low-pressure liquid chromatography (99.04±0.01%) showed optimum recovery of crocin. Whereas for safranal, microwave-assisted extraction (15.9±0.1%) and ultraviolet (UV) spectrophotometry preferred methods. The analysed data will be useful for future studies that focus on the analysis of saffron secondary metabolites and potentiality in cancer treatments to provide the researchers with a wide range of alternatives for carrying out the processes of curing cancers.&#x0D; Keywords: Anticancer, Crocin, Crocetin, Safranal, Saffron

Uncovering the Bioactivity of Aurantiochytrium sp.: a Comparison of Extraction Methodologies.

Aurantiochytrium sp. is an emerging alternative source of polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA), and squalene, playing an important role in the phasing out of traditional fish sources for these compounds. Novel lipid extraction techniques with a focus on sustainability and low environmental footprint are being developed for this organism, but the exploration of other added-value compounds within it is still very limited. In this work, a combination of novel green extraction techniques (high hydrostatic pressure extraction (HPE) and supercritical fluid extraction (SFE)) and traditional techniques (organic solvent Soxhlet extraction and hydrodistillation (HD)) was used to obtain lipophilic extracts of Aurantiochytrium sp., which were then screened for antioxidant (DPPH radical reduction capacity and ferric-reducing antioxidant potential (FRAP) assays), lipid oxidation protection, antimicrobial, anti-aging enzyme inhibition (collagenase, elastase and hyaluronidase), and anti-inflammatory (inhibition of NO production) activities. The screening revealed promising extracts in nearly all categories of biological activity tested, with only the enzymatic inhibition being low in all extracts. Powerful lipid oxidation protection and anti-inflammatory activity were observed in most SFE samples. Ethanolic HPEs inhibited both lipid oxidation reactions and microbial growth. The HD extract demonstrated high antioxidant, antimicrobial, and anti-inflammatory activities making, it a major contender for further studies aiming at the valorization of Aurantiochytrium sp. Taken together, this study presents compelling evidence of the bioactive potential of Aurantiochytrium sp. and encourages further exploration of its composition and application.

High hydrostatic pressure extract of mulberry leaves ameliorates hypercholesterolemia via modulating hepatic microRNA-33 expression and AMPK activity in high cholesterol diet fed rats.

BackgroundMulberry leaf (Morus alba L.) contains multiple bioactive ingredients and has been used in the treatment of obesity, diabetes, inflammation, and atherosclerosis. High hydrostatic pressure (HHP) processing has been developed for the extraction of bioactive compounds from plants. However, the hypocholesterolemic effect of the HHP extract from mulberry leaves and its underlying mechanism have never been investigated.ObjectiveThe specific aim of the present study was to investigate the hypocholesterolemic property of a novel extract obtained from mulberry leaves under HHP in rats.DesignSprague–Dawley rats were divided into four groups and fed either a normal diet (NOR), a high cholesterol diet containing 1% cholesterol and 0.5% cholic acid (HC), an HC diet containing 0.5% mulberry leaf extract (ML), or a 1% mulberry leaf extract (MH) for 4 weeks.ResultsHigh hydrostatic pressure extract of mulberry leaves significantly reduced the HC-increased serum levels of triglyceride (TG), cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), and hepatic contents of TG and TC. The HHP extraction from mulberry leaves also increased the HC-decreased fecal TC and bile acid levels without changing body weight, food intake, liver weight, and serum activities of alanine transaminase (ALT) and aspartate transaminase (AST) (P < 0.05). The mulberry leaf extract significantly enhanced the expression of hepatic genes such as cholesterol 7 alpha-hydroxylase (CYP7A1), liver X receptor alpha (LXRα), and ATP-binding cassette transporters, ABCG5/ABCG8, involved in hepatic bile acid synthesis and cholesterol efflux (P < 0.05). In addition, the HHP extraction of mulberry leaves significantly suppressed hepatic microRNA(miR)-33 expression and increased adenosine monophosphate-activated protein kinase (AMPK) activity.ConclusionThese results suggest that the HHP extract of mulberry leaves lowers serum cholesterol levels by partially increasing hepatic bile acid synthesis and fecal cholesterol excretion through the modulation of miR-33 expression and AMPK activation in the liver.

Enhanced Antioxidant Capacity of Puffed Turmeric (Curcuma longa L.) by High Hydrostatic Pressure Extraction (HHPE) of Bioactive Compounds.

Turmeric (Curcuma longa L.) is known for its health benefits. Several previous studies revealed that curcumin, the main active compound in turmeric, has antioxidant capacity. It has been previously demonstrated that puffing, the physical processing using high heat and pressure, of turmeric increases the antioxidant and anti-inflammatory activities by increasing phenolic compounds in the extract. The current study sought to determine if high hydrostatic pressure extraction (HHPE), a non-thermal extraction at over 100 MPa, aids in the chemical changes and antioxidant functioning of turmeric. 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) analyses were conducted and assessed the content of total phenol compounds in the extract. The chemical changes of curcuminoids were also determined by high performance liquid chromatography (HPLC). Among the three variables of ethanol concentration, pressure level, and treatment time, ethanol concentration was the most influential factor for the HHPE of turmeric. HHPE at 400 MPa for 20 min with 70% EtOH was the optimal extraction condition for the highest antioxidant activity. Compositional analysis revealed that 2-methoxy-4-vinylphenol was produced by puffing. Vanillic acid and ferulic acid content increased with increasing HHPE time. Synergistic effect was not observed on antioxidant activity when the turmeric was sequentially processed using puffing and HHPE.

Effects of High Hydrostatic Pressure assisted degreasing on the technological properties of insect powders obtained from Acheta domesticus &amp; Tenebrio molitor

Abstract In this study, two edible insect species; Acheta domesticus (house cricket) and Tenebrio molitor (yellow mealworm) were defatted using different extraction methods and characterized afterwards. The main goal of the study was to see the effect of High Hydrostatic Pressure (HHP) extraction at different temperatures on the functional properties of the insect powders. Protein content, solubility, water and oil binding capacity; total phenolic content and antioxidant activity were all effected from the extraction method. Results showed that, temperature increase from 30 to 40 °C caused a decrease in the protein solubility of both powders. NMR relaxometry was used to interpret the gelation behavior and FTIR spectroscopy showed absorbance peaks mainly in amide I, amide II and amide III regions for both species. Results confirmed that HHP can be used for defatting purposes and could improve the functional properties of the powders to be used as a food additive in formulations.

Effect of High Hydrostatic Pressure Extraction on Biological Activities and Phenolics Composition of Winter Savory Leaf Extracts.

Satureja montana L. has several biological properties related to its diverse composition of secondary metabolites. Nevertheless, it has been mainly studied for its essential oil, with only a few studies on the profile and bioactivities of the bioactive compounds from its leaf extracts being reported. This work aimed to study the antioxidant activity (by oxygen radical absorbance capacity (ORAC) assay), antimicrobial minimum inhibitory and bactericidal concentrations (MIC and MBC) determination, antibiofilm (by colorimetry), impact upon DNA (anti- and pro-oxidant assay), and cytotoxicity (by cell metabolism viability assays) of S. montana extracts obtained by high-pressure-assisted extraction (HPE). The extract obtained at 348 MPa, 35% (v/v) ethanol presented the highest concentration of individual phenolic compounds, and a minimum bactericidal concentration of 20 mg/mL against Listeria monocytogenes. HPE extracts showed antioxidant activity not only in ORAC but they were also able to prevent/attenuate peroxide-induced damage upon DNA. Moreover, on its own, HPE extract induced less oxidative damage than the control extract. Concerning the cytotoxicity, HPE extracts (at 0.5 and 1.0 mg/mL) were not harmful to HT29 cell lines, while control extracts (obtained at atmospheric pressure) at higher concentrations (>1.0 mg/mL) slightly reduced the metabolism of the cells. Finally, all extracts showed inhibition of the viability of 3 cancerous cell lines (>2.0 mg/mL for Caco-2, HeLa, and TR146) to below 15%.

Optimization of high hydrostatic pressure extraction of bioactive compounds from noni fruits

The consumption of noni fruits has been linked to several health benefits, many of which are attributed to scopoletin, alizarin and rutin that are present in the fruits. However, there is no report on optimized high hydrostatic pressure (HHP) extraction of noni fruits. In this study, the effects of ethanol concentration, pressure and time were evaluated individually on the extraction yields of bioactive compounds from noni fruits. The optimum extraction condition was then investigated to maximize the yields using response surface methodology with a Box-Behnken Design. The extraction pressure and ethanol concentration were the most statistically significant variables in obtaining high extraction yields. The optimal HHP extraction condition at the highest desirability (> 0.998) for simultaneous extraction of scopoletin, alizarin and rutin was as follows: pressure 544 MPa, time 15 min and ethanol concentration 65%, which gave the maximum yields of 82.4, 77.2 and 82.2% for scopoletin, alizarin and rutin, respectively. All bioactive compounds showed the positive linear and negative quadratic effects of pressure, the negative linear and negative quadratic effects of ethanol concentration, and the negative interaction effect between pressure and ethanol concentration on extraction yields. This study highlights the applicability of HHP in extracting bioactive compounds from noni fruits, taking advantage of high yield, extraction time saving and reduced solvent volume at room temperature.

Insight into High-Hydrostatic Pressure Extraction of Polyphenols from Tomato Peel Waste.

In this paper, high-hydrostatic pressure extraction (HHPE) as an emerging food processing and preservation technique constitutes an alternative to conventional thermal treatment that has been used for extraction of polyphenols from tomato peel waste generated by the canning industry. The impact of time (5 and 10min), temperature (25, 35, 45 and 55°C) and solvents (water, 1% HCl, 50 and 70% methanol with and without addition of HCl, and 50 and 70% ethanol), at a constant pressure of 600MPa, has been evaluated in this paper with respect to polyphenols' yields. The results showed a significant (p < 0.05) variation in the contents of a great number of phenolic compounds in respect of the applied temperatures and solvents. On the other hand, the time invested in HHPE had no effect on polyphenols' yields. Among phenolic compounds, the p-coumaric acid (p-CA) and chlorogenic acid derivative (ChA der) are predominant, i.e., 0.57 to 67.41mg/kg and 1.29 to 58.57mg/kg, respectively, depending on the solvents and temperatures used. In particular, methanol (50 and 70%) at temperatures of 45 and 55°C enhanced the recovery of polyphenols in comparison to other utilised solvents. In conclusion, this paper puts forth the theory that by applying HHPE with minimal expenditure of time, it is possible to achieve efficient production of polyphenols from low-cost tomato peel waste, generating income both for producers and agri-food industries.

Application of high hydrostatic pressure and ultrasound-assisted extractions as a novel approach for pectin and polyphenols recovery from tomato peel waste

In this study, high hydrostatic pressure extraction (HHPE) and ultrasound-assisted extraction (UAE) were used for the improvement of pectin and polyphenol recovery from tomato peel waste.HHPE enhanced pectin recovery by 15% after 45 min of recycling, in comparison with the conventional extraction (CE) for 180 min. Similar mass fractions of anhydrouronic acid, total sugars and total phenols were obtained by using both methods. FTIR and 1H NMR data confirmed that chemical composition of pectin obtained by HHPE and CE is identical, therefore it was concluded that the faster HHPE method can be used for its further isolation.Although depectinized residues subjected to UAE in 70% ethanol for 15 min contained two times lower values of total phenols (1625.7 mg/100 g) than pectinized samples (3643.9 mg/100 g), their quantities are not negligible, considering the fact that they are generated after HHPE. At the end of UAE, the residues were exploited as a source of fatty acids, among which lauric, palmitic and stearic acids are dominant.In conclusion, by shortening the extraction time using HHPE and UAE, it is possible to efficiently produce two valuable functional ingredients, pectin and polyphenols, and at the same time to reduce peel waste from tomato canning industry, which presents an environmental problem. Industrial relevanceUtilizing HHPE and UAE as novel and emerging technologies, and combining them with traditional ones (Soxhlet) is given the solution for sequential isolation of pectin, polyphenols and fatty acids from tomato peel waste, generated by canning factory.Shortening of extraction time using HHPE and UAE, it is possible to replace the conventional techniques, and achieve efficient production of pectin and polyphenols.Overall, the extraction methodology proposed in this work could provide two valuable benefits, i.e. the producers could find mode for decreasing of disposal costs of waste and consumer would take opportunity that isolated compounds could be reintroduced into food.

Effect of high hydrostatic pressure extraction on biological activities of stinging nettle extracts.

Stinging nettle is traditionally used as a therapeutic herb. In the present work, the biological properties and toxicity of novel nettle leaf extracts obtained by high pressure assisted extraction (HPE) were studied and compared with similar extracts obtained with the same solvent under atmospheric pressure conditions. The studied extracts were obtained at pressure levels of 200 and 500 MPa, ≈10 min, 0 to 70% ethanol : water (v/v). Each extract was characterized for its individual compound profile and different biological properties, such as antioxidant activity, pro-oxidant activity (DNA degradation capacity) and antihypertensive activity, as well as cytotoxicity against Caco-2 and HaCat cell cultures. The main results indicate that in addition to the antioxidant and antihypertensive activities observed for the control extracts, a clear improvement of all the biological activities of the extracts obtained by HPE was observed. The extracts obtained at 200 MPa, 10 min, 35 and 70% ethanol were the ones presenting higher concentrations of phenolic acids and flavonoids, such as chlorogenic acid, isoferulic acid, and rutin; besides, they showed better results concerning all the studied biological activities. Those extracts also showed potential for DNA protection, since they were able not only to cause less damage in the DNA molecule than the controls, but also showed no pro-oxidant activity. Concerning cytotoxicity, it was observed that HPE extracts, at a concentration up to 1.0 mg mL-1, presented a metabolism inhibition below 10 and 15% for Caco-2 and HaCat cell lines, respectively.

A Square Wave Voltammetry Study on the Antioxidant Interaction and Effect of Extraction Method for Binary Fruit Mixture Extracts

Square wave voltammetry (SWV) analysis was used to assess the antioxidant interactions (synergism, addition, and antagonism) of fruit mixture extracts from grape (G), lemon (L), and blueberry (B) obtained by conventional extraction, ultrasound-assisted extraction, and high hydrostatic pressure extraction. The experimental results showed antagonistic antioxidant effects in all binary mixture extracts (L-G, L-B, and G-B). In DPPH and FRAP assays, the greatest antioxidant capacity was found in the G-B mixture (108.7 and 108.8 μmol TE g−1dry extract, respectively) obtained by high hydrostatic pressure extraction; however, there were no significant differences when measured by ultrasound-assisted extraction. For TPC and TFC assays, the greatest values were for G-B (6.67 mg GA g−1dry extract) and L-G (1.63 mg QE g−1dry extract), respectively. SWV experiments showed antagonistic behavior in the mixtures. Among the different ratios of the fruit mixture extracts evaluated by SWV, 1 : 1 (w/w) combination showed the greatest antagonistic antioxidant effects. SWV suggests the components of the mixture with the highest antioxidant capacity oxidize after mixing. The results indicate that the presence of natural bioactive antioxidants in fruit mixtures does not guarantee that the interactions are synergistic.

Ginsenoside composition of Panax ginseng flower extracts obtained using different high hydrostatic pressure extraction conditions

Ginsenosides are active constituents of ginseng (Panax ginseng) that have possible anti-aging, physiological and pharmacological activities, such as anti-cancer and anti-inflammatory effects. Although the ginseng root is generally used more often than the aerial parts for medicinal purposes, the flowers also contain numerous ginsenosides, including Rb2, Rc, Rd, Re and Rg1. Therefore, an extract from the flowers of the P. ginseng could have the pharmacological efficacy of bioactive compounds including ginsenosides. The high hydrostatic pressure extraction (HHPE) is a method that is used for the efficient extraction of bioactive compounds from plant materials. In this study, we compared the yield of ginsenosides from ginseng flowers under different conditions of extraction pressure and time of HHPE. The results indicate that the total yield of the ginsenosides improved as the pressure increased from 0.1 to 80 MPa and treatment duration increased to 24 hours. In addition, the ginsenoside extracts from HHPE at 80 MPa, which possessed a higher total ginsenoside concentration, decreased the viability of the primary human epidermal keratinocytes (HEKs) significantly than the ginsenoside extracts from HHPE at 0.1 MPa. Collectively, we found that the method of HHPE that was performed for 24 hours at 80 MPa showed the highest yield of ginsenosides from the flowers of P. ginseng. In addition, our study provides a foundation for the efficient extraction of ginsenosides, which had a potent bioactivity, from flowers of P. ginseng through HHPE.

High pressure extraction increases the antioxidant potential and in vitro bio-accessibility of bioactive compounds from discarded blueberries

ABSTRACTUnlike conventional extraction (CE) methods, high hydrostatic pressure extraction (HHPE) uses less solvent volume and reduced extraction times. We show here that HHPE increases extractability, antioxidant capacity and bio-accessibility of the bioactive compounds from discarded blueberries when compared to CE. Bioactive compounds were extracted by CE with agitation and by HHPE at 500 MPa for 5, 10 and 15 min. The highest content of anthocyanins (117.08mg 100g−1 FW), polyphenols (9.56mg 100g−1 FW), flavonoids (0.62mg 100g−1 FW) and antioxidant capacities (1853.69 and 2059.55 μMg−1 FW for DPPH and FRAP, respectively) with HHPE for 15 min. Likewise, HHPE for 15 min resulted in the highest bio-accessibility of polyphenols (62.2%) and flavonoids (62.2%), whereas 85.1% and 60.9% of antioxidant capacity measured as DPPH and FRAP, respectively. Only anthocyanins showed decreased bio-accessibility after HHPE. Antioxidant potential of discarded blueberries can be enhanced with HHPE by increasing the extractability of bioactive compounds and their bio-accessibility.

Enhancement of Bioactivity of Natural Extracts by Non-Thermal High Hydrostatic Pressure Extraction.

Natural extracts, like those obtained from medicinal herbs, dietary plants and fruits are being recognized as important sources of bioactive compounds with several functionalities including antioxidant, anticancer, and antimicrobial activities. Plant extracts rich in phenolic antioxidants are currently being successfully used for several pharmaceutical applications and in the development of new foods (i.e., functional foods), in order to enhance the bioactivity of the products and to replace synthetic antioxidants. The extraction method applied in the recovery of the bioactive compounds from natural materials is a key factor to enhance the bioactivity of the extracts. However, most of the extraction techniques have to employ heat, which can easily lead to heat-sensitive compounds losing their biological activity, due to changes caused by temperature. Presently, high hydrostatic pressure (HHP) is being increasingly explored as a cold extraction method of bioactive compounds from natural sources. This non-thermal high hydrostatic pressure extraction (HHPE) technique allows one to reduce the extraction time and increase the extraction of natural beneficial ingredients, in terms of nutritional value and biological activities and thus enhance the bioactivity of the extracts. This review provides an updated and comprehensive overview on the extraction efficiency of HHPE for the production of natural extracts with enhanced bioactivity, based on the extraction yield, total content and individual composition of bioactive compounds, extraction selectivity, and biological activities of the different plant extracts, so far studied by extraction with this technique.

Thermal-assisted high hydrostatic pressure extraction of nutraceuticals from saffron (Crocus sativus): Process optimization and cytotoxicity evaluation against cancer cells

The extraction of nutraceuticals (crocin, picrocrocin, and safranal) from saffron was conducted using high hydrostatic pressure. A pressure range of 100–600 MPa in combination with elevated temperatures (30–70 °C) was studied. Extract quality was determined by an ISO (the international organization for standardization) method, and also compared with HPLC analysis. The results showed a significantly (P < 0.05) positive effect of pressure on the extract quality with an increase of 52–63%, 54–85%, and 55–62% in crocin, picrocrocin, and safranal content, respectively, as the pressure increased. However, a highly significant decrease (25–36%) in crocin content was observed with the increase in temperature. Moreover, the effect of pressure on saffron components varied with the change in temperature which was observed from the response surfaces. A third-order model showed a good fit (R2 > 0.9) of these data including pressure effect on crocin, picrocrocin, and safranal content. An optimum pressure-temperature combination of 580 MPa and 50 °C with an extraction time of 5 min (dwell time) was obtained, predicting 100, 50, and 92 units of crocin, safranal, and picrocrocin content, respectively. A <5% error was found between the predicted and experimental values. Anti-cancer activity of the optimized extract obtained under high hydrostatic pressure was evaluated using MTT (3,(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) based assay, which showed a 28% higher anti-cancer activity as compared to the conventionally extracted sample. High hydrostatic pressure proved to be a better technology than conventional process for extraction of bioactive components from saffron, the highest valued spice in the world. Pressure-extracted components of saffron can be used to formulate functional foods or directly applied for clinical trials.