Extraction pH Research Articles

Effect of heat treatment and extraction pH on macroscopic and molecular properties of dromedary milk gel induced by Urtica dioica extracts

Effect of heat treatment and extraction pH on macroscopic and molecular properties of dromedary milk gel induced by Urtica dioica extracts

Enhancing Analytical Sensitivity and Selectivity for Methylene Blue Determination in Water Samples by Using Multiphase Electroextraction Coupled with Optical Absorption Spectroscopy and Surface-Enhanced Raman Scattering.

While optical analysis spectroscopy offers operational ease and low cost, it suffers from limitations regarding sensitivity when it comes to analyzing analytes at low concentrations. On the other hand, surface-enhanced Raman spectroscopy (SERS) offers high sensitivity but low selectivity in complex matrices. In this study, we have effectively addressed these challenges by integrating multiphase electroextraction (MPEE) as a sample preparation technique with these two spectroscopic methods for determining methylene blue (MB) dye in tap water samples. A Box-Behnken design was utilized for optimizing electroextraction parameters such as extraction time, pH, and acetonitrile percentage in the donor phase. After optimization, optical absorption spectroscopy results in a linear analytical curve within the range of 30 to 375 mg L-1 of MB, with method validation demonstrating high precision (relative standard deviation between 3.0 and 9.9%), recovery (99-105%), and detection and quantification limits of 1.3 and 4.0 μg L-1, respectively. On the other hand, using SERS, it was possible to detect MB in concentrations as low as 0.05 μg L-1. The extremely low concentrations of MB detected (in the range of a few ppb and ppt) and the acceptable validation performance parameters obtained highlight the potential of MPEE to enhance the applicability of spectroscopic techniques in routine analyses, especially when dealing with complex and challenging samples.

Screening factors to affect ultrasound-assisted extraction of (poly)phenols from date palm seeds.

The aim of the current work was to compare the (poly)phenol profile (free, soluble-conjugate, and insoluble-bound) and antioxidant activity of date palm seed flour using different extraction methods (conventional vs. ultrasound-assisted extraction [UAE]) and to determine the most critical variables in the extraction of (poly)phenols through UAE using the Plackett-Burman design experiment. Using the Plackett-Burman design, seven factors, namely, ethanol concentration, liquid:solid ratio (mL/g), sonotrode, amplitude (%), extraction time, extractant pH, and extraction cycle, were studied. After the factors were studied using conventional extraction methods, 23 compounds were quantified, with protocatechuic acid and catechin being the predominant (poly)phenols. Furthermore, the distribution of (poly)phenols within the cell varied, with glycosylated quercetins and caffeoyl shikimic acids predominantly found in free forms. Ultrasound-assisted extraction demonstrated efficiency in extracting free and soluble-conjugate (poly)phenols. However, it showed limitations in extracting insoluble-bound (poly)phenols. Nevertheless, similar amounts of total (poly)phenols were shown after conventional extraction and UAE, that is, 259.69 ± 43.54 and 189.00 ± 3.08mg/100g date seed flour, respectively. The Plackett-Burman design revealed the liquid-solid ratio as a crucial factor affecting (poly)phenol extraction, with higher ratios yielding better results. The sonotrode choice also influenced the extraction efficiency, highlighting that the sonotrode with a smaller diameter but higher displacement amplitude showed the best polyphenol recovery and antioxidant activity values. The nature of (poly)phenols influenced the studied extraction variables differently, emphasizing the complexity of the extraction process. In this line, pure water was sufficient to extract flavan-3-ols after UAE, whereas ethanol was a crucial factor in extracting quercetin. These findings underscore the importance of optimizing extraction methods for maximizing (poly)phenol recovery from date palm seed flour for various applications in food and pharmacology industries.

Ultrasound-assisted extraction, optimisation using response surface methodology and HPLC-DAD phenolic compounds quantification from Passiflora edulis S. peels cultivated in Tunisia

A new ultrasound-assisted extraction method was developed for the determination of phenolic compounds extracted from Passiflora edulis Sims peels cultivated in Tunisia. Several extraction variables including: extraction time, temperature, liquid/solid ratio and pH have been studied using response surface methodology. The extraction efficiency was evaluated by measuring the total phenolics; flavonoids and antioxidants content. The highest values of the studied response were observed after 9.78 min at 49.64 °C in a liquid-to-solid ratio 22.07 ml/g and in pH (5.54). The individual phenolic compounds content of the optimum extract peels of the Passiflora edulis Sims have been analysed using HPLC-DAD. The results revealed the presence of gallic followed by caffeic acids, while the apigenin-7-glucoside and rutin have been quantified as the abundant flavonoid compounds (0.653 and 0.488 mg/ml, respectively). This green procedure should be a promising option to guide industrial design for the production of phenolic-rich plant extracts.

Attenuation of the effect of salinity on redwood (Caesalpinia platyloba) by saline compost

The objective of this research is to evaluate the effect of saline compost on the attenuation of salinity stress in palo colorado (Caesalpinia platyloba). A representative sample of saline soil was taken at Ciudad Universitaria Intercultural, sieved (mesh < 5mm) and composted with cattle manure and Cynodon dactylon garden grass pruning, in a 3:1:1 ratio (stubble: manure: saline soil), for 120 days, the characterization consisted of measuring the bulk density (DA), saturation point, pH and EC of the saturated paste extract. The effect of different concentrations of NaCl on the in vitro germination of palo colorado seeds was evaluated in a randomized complete block design with two substrates (blocks), B1) sand-perlite; B2) sand-perlite-salt compost, five treatments 0 M, 0.3 M, 0.4 M, 0.5 M and 0.6 M of NaCl, eight replicates per treatment. The control irrigation was with distilled water. The plants transference to polyethylene cups was fifteen days after sowing; the cups had the same substrate mixture. The variables measured were survival, leaf biomass and dry root biomass. The EC decreased during composting, from 9.45 dS/m low to 2.4 dS/m; the pH of the samples did not show a significant difference. It is concluded that neither the substrate nor the NaCl concentration significantly influenced the germination of palo colorado seeds, and that the saline compost had no effect on the mitigation of salt stress in palo colorado plants.

Unveiling differential impact of heat and microwave extraction treatments on the structure, functionality, and digestibility of jack bean proteins extracted under varying extraction pH

The poor extractability and digestibility of jack beans restrict their application in food systems. Thermal treatment could be a processing tool to disrupt the compact conformation of the plant matrix and inactivate inherent antinutrients. Therefore, this research investigated the impact of conventional heat-aided (HA-) and microwave-aided (MA-) extraction treatments on the structure, functional properties, and digestibility of jack bean protein concentrate (JBPC) under varying extraction pH. The novelty brought by the present study is establishing the thermal treatment/extraction pH combinations for improving techno-functionalities and digestibility of JBPC. Heat (50 °C for 1 h) and sequential microwave power (400 W, 600 W, and 800 W for 5 min) at three extraction pH (9.0, 10.0, and 11.0) were studied. Upon increasing extraction pH, a significant decrease in the protein content, and β-Sheet structure was observed, in the order of pH 11.0 > 10.0 > 9.0. JBPC extracted using HA treatments displayed the highest contents of surface hydrophobicity (90.02) and sulfhydryl groups. In functional properties, MA-extracted JBPC under 400 W showed significantly improved solubility (93.45 %), emulsifying activity index (45.23 m2/g), and foaming capacity (141.70 %) when compared to other thermal treatments. The degree of hydrolysis result revealed that MA treatment improved the JBPC in vitro digestibility at a low power level of 400 W. These findings suggest that MA extraction treatment can improve the functional and nutritional properties of JBPC regardless of the extraction pH, and thus, expand the potential application in food systems.

Stability of Propolis Phenolics during Ultrasound-Assisted Extraction Procedures.

Propolis has gained popularity in recent years as a potential preventive and therapeutic agent due to its numerous health benefits, which include immune system boosting, blood pressure lowering, allergy treatment, and skin disease treatment. The pharmacological activity of propolis is primarily attributed to phenolics and their interactions with other compounds. Given that phenols account for most of propolis's biological activity, various extraction methods are being developed. The resin-wax composition of the propolis matrix necessitates the development of an extraction procedure capable of breaking matrix-phenol bonds while maintaining phenol stability. Therefore, the aim of this study was to assess the stability of two major groups of phenolic compounds, flavonoids and phenolic acids, in propolis methanol/water 50/50 (v/v) extracts obtained after ultrasound-assisted extraction (USE) under different extraction parameters (extraction time and pH) and heat reflux extraction (HRE). The methodology involved varying the USE parameters, including extraction time (5, 10, and 15 min) and pH (2 and 7), followed by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify phenolic recoveries. Results revealed that benzoic acid and chlorogenic acid derivatives demonstrated excellent stability across all ultrasound extraction procedures. The recoveries of flavonoids were highly diverse, with luteolin, quercitrin, and hesperetin being the most stable. Overall, neutral pH improved flavonoid recovery, whereas phenolic acids remained more stable at pH = 2. The most important optimization parameter was USE time, and it was discovered that 15 min of ultrasound resulted in the best recoveries for most of the phenols tested, implying that phenols bind strongly to the propolis matrix and require ultrasound to break the bond. However, the high variability in phenol extraction and recovery after spiking the propolis sample shows that no single extraction method can produce the highest yield of all phenols tested. As a result, when working with a complex matrix like propolis, the extraction techniques and procedures for each phenol need to be optimized.

Influence of extraction pH and homogenization on soybean oleosome emulsion stability

Oleosomes are highly conserved organelles that store oil and can be utilized as a natural oil-in-water emulsion for food products when isolated intact. Although soybeans are a rich source of oleosomes, their potential has not been fully realized due to significant aggregation within the emulsion, which limits their applications. This study investigates the effect of homogenization as a strategy to prevent oleosome aggregation and coalescence. Our results indicate that homogenization at pressures of 10–30 MPa effectively prevents phase separation and preserves the initial particle size of oleosomes. However, at pressures of 40–50 MPa, oleosome particles are disrupted, leading to the formation of smaller particles that stabilize the emulsion against coalescence. We found that extracting oleosomes at a pH of 9 consistently produces stable emulsions, suggesting this method as a viable approach to enhance the stability of these emulsions. Furthermore, extraction at a pH of 7 followed by homogenization enhances the physical stability of the mixtures. Additionally, our findings demonstrate that performing extractions at pH 9 helps in preserving oleosome membrane-associated proteins, thereby further improving the stability and extending the storage potential of soybean oleosomes to up to 20 days.

Effects of Alkaline Extraction pH on Amino Acid Compositions, Protein Secondary Structures, Thermal Stability, and Functionalities of Brewer's Spent Grain Proteins.

A high alkaline pH was previously demonstrated to enhance the extraction yield of brewer's spent grains (BSG) proteins. The effects of extraction pH beyond the extraction yield, however, has not been investigated before. The present work examined the effects of extraction pH (pH 8-12) on BSG proteins' (1) amino acid compositions, (2) secondary structures, (3) thermal stability, and (4) functionalities (i.e., water/oil holding capacity, emulsifying, and foaming properties). The ideal extraction temperature (60 °C) and BSG-to-solvent ratio (1:20 w/v) for maximizing the extraction yield were first determined to set the conditions for the pH effect study. The results showed that a higher extraction pH led to more balanced compositions between hydrophilic and hydrophobic amino acids and higher proportions of random coils structures indicating increased protein unfolding. This led to superior emulsifying properties of the extracted proteins with more than twofold improvement between pH 8 and a pH larger than 10. The extraction pH, nevertheless, had minimal impact on the water/oil holding capacity, foaming properties, and thermal denaturation propensity of the proteins. The present work demonstrated that a high alkaline pH at pH 11-12 was indeed ideal for both maximizing the extraction yield (37-46 wt.%) and proteins' functionalities.

Alterations in pH of Coffee Bean Extract and Properties of Chlorogenic Acid Based on the Roasting Degree.

Factors influencing the sour taste of coffee and the properties of chlorogenic acid are not yet fully understood. This study aimed to evaluate the impact of roasting degree on pH-associated changes in coffee bean extract and the thermal stability of chlorogenic acid. Coffee bean extract pH decreased up to a chromaticity value of 75 but increased with higher chromaticity values. Ultraviolet-visible spectrophotometry and structural analysis attributed this effect to chlorogenic and caffeic acids. Moreover, liquid chromatography-mass spectrometry analysis identified four chlorogenic acid types in green coffee bean extract. Chlorogenic acid isomers were eluted broadly on HPLC, and a chlorogenic acid fraction graph with two peaks, fractions 5 and 9, was obtained. Among the various fractions, the isomer in fraction 5 had significantly lower thermal stability, indicating that thermal stability differs between chlorogenic acid isomers.

Physicochemical and functional characteristics of a gourd (Cucurbita argyrosperma Huber) seed protein isolate subjected to high-intensity ultrasound

The impact of high-intensity ultrasound (HIU, 20 kHz) on the physicochemical and functional characteristics of gourd seed protein isolate (GoSPI) was studied. GoSPI was prepared from oil-free gourd seed flour through alkaline extraction (pH 11) and subsequent isoelectric precipitation (pH 4). The crude protein concentration of GoSPI ranged from 91.56 ± 0.17 % to 95.43 ± 0.18 %. Aqueous suspensions of GoSPI (1:3.5 w/v) were ultrasonicated at powers of 200, 400, and 600 W for 15 and 30 min. Glutelins (76.18 ± 0.15 %) were the major protein fraction in GoSPI. HIU decreased the moisture, ash, ether extract, and nitrogen-free extract contents and the hue angle, available water and a* and b* color parameters of the GoSPI in some treatments. The L* color parameter increased (7.70 %) after ultrasonication. HIU reduced the bulk density (52.63 %) and particle diameter (39.45 %), as confirmed by scanning electron microscopy, indicating that ultrasonication dissociated macromolecular aggregates in GoSPI. These structural changes enhanced the oil retention capacity and foam stability by up to 62.60 and 6.84 %, respectively, while the increases in the solvability, water retention capacity, and emulsifying activity index of GoSPI were 90.10, 19.80, and 43.34 %, respectively. The gelation, foaming capacity, and stability index of the emulsion showed no improvement due to HIU. HIU altered the secondary structure of GoSPI by decreasing the content of α-helices (49.66 %) and increasing the content of β-sheets (52.00 %) and β-turns (65.00 %). The electrophoretic profile of the GoSPI was not changed by HIU. The ultrasonicated GoSPI had greater functional attributes than those of the control GoSPI and could therefore be used as a functional food component.

Synthesis and Characterization of Silver Nanoparticles Using Bioreductant Andong Leaf Extract (Cordyline fruticosa (L) A. Chev.)

Silver nanoparticles are known to play a crucial role in various fields, prompting researchers to undertake synthesis and modification to obtain nanoscale particles. Silver nanoparticles were synthesized using a green synthesis-based chemical method with an extract from Cordyline fruticosa (L.) A. Chev. This study aims to determine the optimum conditions, including pH parameters, reaction time, and concentration, and assess the silver nanoparticles’ stability and characteristics. The research findings revealed that the optimal conditions for synthesizing silver nanoparticles were an extract pH of 11, a reaction time of 60 minutes, a AgNO3 concentration of 1.5 x 10-4 M, and an extract concentration of 0.008%. Characterization showed that silver nanoparticles were spherical, ranging from 5 to 20 nm and had an average hydrodynamic size distribution of 100.8 nm. In conclusion, leaf extract of Cordyline fruticosa (L.) A. Chev. can be utilized as a bioreductant and stabilizing agent, as indicated by stability test results, which showed considerable stability over a storage period of three months.

Assessing the Air Pollution Tolerance Index of Urban Plantation: A Case Study Conducted along High-Traffic Roadways

Road transport and traffic congestion significantly contribute to dust pollution, which negatively impacts the growth of roadside plants in urban areas. This study aims to quantify the air pollution tolerance index (APTI) and analyze the impacts of dust deposition on different plant species and trees planted along a busy urban roadside in Lahore, Pakistan by considering seasonal variations. The APTI of each species is determined based on inputs of various biochemical parameters (leaf extract pH, ascorbic acid content, relative water content, and total chlorophyll levels), including dust deposition. In this study, laboratory analysis techniques are employed to assess these factors in selected plant species such as Mangifera indica, Saraca asoca, Cassia fistula, and Syzygium cumini. A statistical analysis is conducted to understand the pairwise correlation between various parameters and the APTI at significant and non-significant levels. Additionally, uncertainties in the inputs and APTI are addressed through a probabilistic analysis using the Monte Carlo simulation method. This study unveils seasonal variations in key parameters among selected plant species. Almost all biochemical parameters exhibit higher averages during the rainy season, followed by the summer and winter. Conversely, dust deposition on plants follows an inverse trend, with values ranging from 0.19 to 4.8 g/cm2, peaking during winter, notably in Mangifera indica. APTI values, ranging from 9.39 to 14.75, indicate varying sensitivity levels across species, from sensitive (Syzygium cumini) to intermediate tolerance (Mangifera indica). Interestingly, plants display increased tolerance during regular traffic hours, reflecting a 0.9 to 5% difference between the APTI at peak and regular traffic hours. Moreover, a significant negative correlation (−0.86 at p < 0.05 level) between APTI values and dust deposition suggests a heightened sensitivity to pollutants during the winter. These insights into the relationship between dust pollution and plant susceptibility will help decision makers in the selection of resilient plants for urban areas and improve air quality.

Valorization of saffron production waste: Isolation of anthocyanins from saffron petal extract by zirconium-based adsorbents

Anthocyanins (ACs) are a group of flavonoids with antioxidant effects and have been considered for their health benefits. Therefore, the development of economic and non-toxic isolation methods for getting high-purity ACs besides new sources of ACs is required. In this study, new nanocomposites polymer based on zirconium including Zr@PANI, Zr@βCyD, and Zr@βCyD-PANI were synthesized, and utilized as a substrate to purify ACs extracted from the petals of Crocus sativus L. To optimize the operational process, the effective parameters such as adsorption time, adsorbent dose, and initial pH that significantly affect the purification of anthocyanin were investigated by a three-level, three-factor Box-Behnken design. The optimized conditions for anthocyanin purification were obtained as follows: adsorption time of 30.83, 31.56, and 61.53 min, substrate dose of 0.072, 0.197, and 0.064 g, and initial pH of extract of 5.06, 4.04, and 7.98 for Zr@PANI, Zr@βCyD, and Zr@βCyD-PANI, respectively. In the following, the HPLC and LC-MS methods were used to analyze the purified ACs of saffron petals. The chromatographic results indicated DEL-3,5-O-diglucoside, PET-3,5-O-diglucoside, CYA-3-O-glucoside, CYA-3,5-O-diglucoside,CYA-3-O-(6-O-acetyl)-glucoside are the major ACs in saffron petals.

Sequential extraction optimization of compounds of interest from spent brewer's yeast biomass treated by Pulsed Electric Fields

The brewing industry produces significant volumes of spent brewer's yeast (SBY), which presents an intriguing opportunity for valorization. This study aims to optimize the extraction of various compounds of interest from electroporated SBY located both in the cytoplasm (amino acids, glutathione and proteins) and in the cell walls (mannoproteins). The optimization of the extraction time, temperature and pH, allowed obtaining an extract rich in glutathione of 2.31 ± 0.15 mg/g dw after 1 h of incubation (pH 8; 30 °C) and, a second extract rich in amino acids (155.74 ± 7.83 mg/g dw) and proteins (331.70 ± 15.64 mg/g dw) after a second incubation (37 °C, 47 h) of the biomass. To achieve comprehensive valorization of SBY, the exhausted yeast biomass was incubated with lyticase to extract mannoproteins from the cell wall. This study showcases the efficacy of a multiple response function in optimizing valuable compound extraction from electroporated SBY, aligning with circularity principles.

Composition and functionality differences of oat protein concentrates: Potential of less refined concentrates obtained by wet milling

The objective of this study was to determine differences in composition and functionality for oat protein concentrates. This was achieved by comparing preparations extracted at different pH levels using either a twin screw press or alkaline extraction followed by isoelectric precipitation. Extraction by twin screw technology provided a higher protein yield compared to isoelectric precipitation. Analysis by SDS-PAGE revealed similar protein composition regardless of the extraction method or extraction pH except for extraction at pH 6. Extraction at a higher pH led to a higher protein purity and yield, while extraction closer to the isoelectric point of the protein resulted in less pure concentrates. All extracts were freeze-dried, and their composition and functionality were compared. Thermal analysis of the protein concentrates extracted by twin screw pressing showed a higher denaturation enthalpy compared to protein isolates prepared by isoelectric precipitation, suggesting that the native structure of the proteins is preserved to a higher extent. All protein fractions exhibited the typical U-shaped solubility profile, except for the concentrate extracted at pH 6, which showed an increase in solubility with increasing pH. Oat protein concentrates prepared by twin screw pressing had a higher affinity for binding to oil than to water, and this was also higher than for isoelectric precipitated protein extracts. Overall results demonstrate a potential for twin screw technology as a viable alternative to conventional wet extraction methods for producing less refined fractions from oats with tunable functional properties.

An ultra-selective and non-enzymatic colorimetric sensor based on imprinted polymer for ephedrine assay in urine samples

A novel non-enzymatic, rapid, and portable molecularly imprinted polymer (MIP)-based colorimetric sensor was developed for ephedrine (EPD) assay in urine samples. The EPD-imprinted polymer was provided via the precipitation polymerization method and applied to fabricate an EPD colorimetric sensor utilizing the carbon disulfide and Cu2+ reagents. The calibration curve for different concentrations of EPD was obtained using the captured images on a cell smartphone and associated RGB data. Some effective parameters including pH of the EPD extraction, time of data collection after adding the reagents, and reagents sequence were investigated and optimized. The selectivity of the sensor was studied using different similar structural compounds, which proved the favorable capability of this method for the selective determination of EPD. This sensor platform with a relatively wide linear calibration range (1–100 μM), and the detection limit of 0.6 μM represents the efficient, reliable, and easy approach for EPD assay in urine samples.

Cyclodextrin-based ternary supramolecular deep eutectic solvents for efficient extraction and analysis of trace quinolones and sulfonamides in wastewater by adjusting pH

BackgroundAntibiotics residues can accelerate the growth of drug-resistant bacteria and harm the ecological environment. Under the effect of enrichment and biomagnification, the emergence of drug-resistant pathogenic bacteria may eventually lead to humans being ineffective to drugs in the face of bacterial or fungal disease infections in the future. It is urgent to develop an efficient separation medium and analytical method for simultaneous extraction and determination of antibiotics in the water environment. ResultsThis work doped 2,6-Di-O-methyl-β-cyclodextrin, randomly methyl-β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin with thymol:fatty acid respectively to construct non-covalent interaction-dominated pH-responsive ternary supramolecular deep eutectic solvents (SUPRADESs), which can undergo a hydrophilic/hydrophobic transition with aqueous phase to achieve an efficient microextraction. Semi-empirical method illustrated that SUPRADESs have a wide range of hydrogen bond receptor sites. We developed a SUPRADES-based analytical method combined with liquid chromatography-triple quadrupole mass spectrometry for the extraction and determination of trace quinolones and sulfonamides in wastewater. The overall limits of detection of the method were 0.0021–0.0334 ng mL−1 and the limits of quantification were 0.0073–0.1114 ng mL−1. The linearity maintained good in the spiked level of 0.01–100 ng mL−1 (R2 > 0.99). The overall enrichment factors of the method were 157–201 with lower standard deviations (≤8.7). SignificanceThe method gave an extraction recovery of 70.1–115.3 % for 28 antibiotics in livestock farming wastewater samples from Zhejiang, China, at trace levels (minimum 0.5 ng mL−1). The results demonstrated that inducing the phase transition between SUPRADES and aqueous phase by adjusting pH for extraction is a novel and efficient pretreatment strategy. To our knowledge, this is the first application of cyclodextrin-based ternary SUPRADESs with pH-responsive reversible hydrophobicity-hydrophilicity transition behavior in wastewater analysis.

The Influence of Substrate and Strain on Protein Quality of Pleurotus ostreatus

Background: The effect of substrate and strain on the nutritional and functional properties of mushroom flours and protein concentrates (PCs) has not thoroughly been investigated. Methods: The proteins of P. ostreatus flours (strains AMRL144 and 150) were isolated following alkaline extraction (pH 12) and isoelectric precipitation (pH 4) as it was determined by the solubility curves. The protein quality of the flours and PCs were evaluated by determining the protein solubility index (PSI) and their functional properties, such as water (WAC) and oil absorption capacity (OAC), foam capacity (FC), foam stability (FS) and emulsion stability (ES). The amino acid (AA) composition of the flours was determined by reversed-phase liquid chromatography after protein hydrolysis and o-phthalaldehyde derivatization. Results: The PSIs of the flours and PCs of P. ostreatus were comparable to those of soy protein flours and protein concentrates. The highest AA concentration was found for both strains when cultivated on the barley and oat straw (BOS) substrate, showing a similar trend as the protein content. A principal component analysis (PCA) indicated an impact of the strain on the functional properties. Conclusions: Both strains can produce high quality proteins especially when cultivated on wheat straw (WS). The FS was positively correlated with the P. ostreatus strain AMRL150 whereas the FC was positively correlated with AMRL144.

The Effect of Microwave-Assisted Extraction Temperature and Material to Solvent Ratio on the Characteristics of Pandan (Pandanus amaryllifolius Roxb.) Leaf Extract

Fresh pandan leaf fragrance has been applied to enhance the aroma of many traditional foods. However, the fresh leaf has a limited shelf life—only 1 day after harvest. Therefore, in liquid or powdered form, pandan extract can be utilized as an alternative aromatic component in food production. The purpose of this study was to determine the effect of extraction temperatures (50, 60, and 70°C) utilizing microwave-assisted extraction (MAE) and the ratio of pandan leaf as material to ethanol as solvent (1:3, 1:7, and 1:11) on the characteristics of pandan extract in liquid form. The study found that the properties of pandan extract treated at MAE 60°C with a material-solvent ratio of 1:7 were the best among all treatments. The pH of this liquid pandan extract was 5.31, the antioxidant activity was 32.86 ppm, and the chlorophyll content was 7.76 mg/L. The powdered pandan extract generated by drying the liquid pandan extract using a spray dryer and adding maltodextrin had properties such as water activity 0.45, solubility 96.09%, solubility rate 0.01 g/s, color L 85.65, a* -6.68, b* 8.51, yield 3.88%, and was detected to contain 0.17% of the aromatic compound 2-acetyl-1-pyrroline. Powdered pandan extract has the potential to be developed as an aromatic food additive. Panelists liked the Lumpang cakes, a traditional cake consisting of rice flour and coconut milk made by adding 1% pandan leaf extract powder.