Pistachio Green Hull Research Articles

Novel and high-performance biochar derived from pistachio green hull biomass: Production, characterization, and application to Cu(II) removal from aqueous solutions

In recent years, biochar is being widely considered as an effective and low cost biosorbent in water and wastewater treatment processes. Various biomasses can be effectively used for biochar production, and this study investigates the use of a novel biochar derived from pistachio green hull to remove Cu(II) from aqueous solutions. The biochar was analyzed by FTIR, SEM-WDX, and SEM-EDX. The efficacy of several experimental factors was investigated in a number of batch adsorption experiments. The sorption kinetics of copper on the biochar were satisfactorily described by a pseudo–second order model. The adsorption isotherms were well described by the Langmuir model. The analysis of experimental results suggested that the Cu(II) sorption onto biochar could mainly be ascribed to cation exchange, surface precipitation, and surface complexation with oxygen-containing functional groups. Overall, it can be concluded that biochar derived from pistachio green hull is valuable as a green cost-effective sorbent for Cu(II) removal from water.

Pistachio green hull pectin: Optimization of microwave-assisted extraction and evaluation of its physicochemical, structural and functional properties

The optimal microwave-assisted extraction conditions of pistachio green hull (PGH) pectin (extraction yield of 18.13%) were in microwave power of 700 W, irradiation time of 165 s, and pH of 1.5. The physico-chemical, structural and functional properties of pectin was examined and the results showed that PGH pectin under optimum conditions was low methoxyl (about 12.1%) with molecular weight of 1.659 kg/mol, emulsifying activity of 58.3%, total phenolic content of 18.18 mg GalAE/g pectin and good surface activity (46.23 and 49.75 mN/m at 0.1 and 0.5% w/v). Also, high performance liquid chromatography analysis illustrated that the pectin is including galacturonic acid (66.0%), arabinose (26.2%), galactose (3.7%), rhamnose (2.7%) and xylose (1.0%). In addition, 1H NMR and FTIR spectrums confirmed the presence of pectin in obtained supenatnt. Surface morphology analysis and X-ray diffraction pattern showed that PGH pectin had a rough surface with crystalline structure.

Nanoliposomes Containing Pistachio Green Hull's Phenolic Compounds as Natural Bio‐Preservatives for Mayonnaise

In this study, encapsulation of pistachio green hull extract (PGHE) into nanoliposomes (NLs) is carried out. Then, different concentrations of free and incorporated phenolic compounds of (500 and 1000 mg kg−1) are added to freshly prepared mayonnaise and samples are evaluated in terms of physicochemical, sensory, and microbial properties during 4 months of storage at 25 °C. The results indicate that the samples containing NLs produced by 2% lecithin and 1000 mg kg−1 of phenolic compounds have the lowest peroxide value (23.23 ± 2.61 meq O2 kg−1 oil) and thiobarbituric acid value (0.92 ± 0.07 mg malondialdehyde kg−1 oil). Free and incorporated phenolic compounds (1000 mg kg−1) exhibit higher antioxidant activity than 200 mg kg−1 of butylated hydroxy toluene (BHT). Free phenolic compounds (EXs) cause significant changes in color parameters (L*, a*, and b*). Regarding sensory evaluation, the samples containing NLs are the most preferred ones. Additionally, NLs having 1000 mg kg−1 of phenolic compounds have the highest inhibitory efficiency on total viable and fungal counts. NLs and EXs have equal effect on Enterobacteriaceae and lactic acid bacteria. Similar to samples containing 1000 mg kg−1 of sodium benzoate, microbial population in samples treated with phenolic compounds is within permissible level after 4 months of storage.Practical applications: The promising results prove that PGHE can be recommended as a natural source of antioxidants and bio‐preservatives instead of synthetic agents to increase the shelf life and safety of mayonnaise. Additionally, NLs enhance stability and solubility of entrapped phenolic compounds of PGHE and decease adverse effects of free ones on sensory properties of mayonnaise. Therefore, incorporation of phenolic compounds of PGHE in the liposomal carrier is a promising method to defeat the limitations of their direct addition to food systems and NLs containing phenolic compounds and plant extracts can also be applied to present novel functional foods. As nanoliposomes are produced by soybean lecithin as an inexpensive, safe and natural source of phospholipids in nanometric particle size, they can be considered for large‐scale use and promotion of biofunctional activities of phenolic compounds in food, pharmaceutical, and cosmetics applications.Firstly, pistachio green hull extract (PGHE) is prepared. Then, different concentrations of phenolic compounds of PGHE are added and blended with the lecithin/water mixture. Lastly, the suspensions are extruded by a mini extruder for producing large unilamellar vesicles. In the next step, liposome‐encapsulated and free phenolic compounds of PGHE are individually added to mayonnaise samples. Based on these findings, incorporation of phenolic compounds of PGHE in liposomal systems can be an appropriate alternative to improve the oxidative and microbial stability of mayonnaise sauce along with minimal effects on sensory attributes.

Evaluation of the inhibitory effect of pistachio (Pistacia vera L.) green hull aqueous extract on mushroom tyrosinase activity and its application as a button mushroom postharvest anti-browning agent

The short shelf life of button mushroom is a serious problem in its postharvest distribution. One approach is the application of plant extract (mainly polyphenolic compounds) to inhibit tyrosinase activity. The inhibitory activity of pistachio green hull extract (PGHE), sodium metabisulfite (MET), and ascorbic-citric acids (ASC-CIT) on mushroom tyrosinase was investigated at different concentrations (0.05–0.8% w/v) and IC50 value was determined (0.07%). Prevention of button mushroom postharvest browning was investigated by vacuum impregnation pretreatment with PGHE, MET, and ASC-CIT. Physicochemical, organoleptic, and microbial properties of the treated mushrooms were determined over 10 d of storage (at 4 °C). The results of the browning index (BI) showed that the PGHE-treated mushrooms had lower BI than the other samples. On the 10th d, only the mushrooms treated with PGHE had highest phenolic content (10.4%). The antioxidant activity of PGHE-treated mushrooms was higher than the control (4.5%). The mushrooms treated by PGHE had 13.9% higher firmness than the control. The sensory evaluation results showed that the samples treated with PGHE had the highest sensory scores. Also, the main components of PGH extract determined by RP-HPLC-DAD were phloroglucinol, gallic acid, naringin, vanillic acid, catechin, and protocatechuic acid. The inhibitory activity of two main components, pure phloroglucinol, gallic acid and the mixture of them, on tyrosinase were 43.6, 24.4 and 42.5%, respectively. It could be concluded that these compounds have a synergistic effect. It can be concluded that pistachio green hull extract is a new natural tyrosinase inhibitor that can delay browning reactions in mushrooms.

Response surface methodology for modelling and determination of catechin in Pistachio green hull using surfactant-based dispersive liquid–liquid microextraction followed by UV–Vis spectrophotometry

A rapid and simple approach for the preconcentration and determination of catechin from pistachio green hull samples has been proposed by surfactant-assisted dispersive liquid–liquid microextraction followed by UV–Vis spectrophotometry (SADLLME/UV–Vis). This method involved the formation of a catechin complex with cetylpyridinium chloride (CPC) as cationic surfactant, and subsequently, DLLME was applied to extract the catechin–CPC complex into chloroform. Different parameters affected the extraction efficiency were optimized by central composite design (CCD) and response surface methodology (RSM). In optimum condition, the calibration curve was linear in the range of 0.4–5 µg mL− 1 of catechin with correlation coefficient of 0.9982. The relative standard deviation based on five replicated analyses of 1 µg mL− 1 catechin was 1.85%. The proposed method was successfully applied for preconcentration and determination of trace amounts of catechin in pistachio hull samples.

Inhibitory activity of phenolic-rich pistachio green hull extract-enriched pasta on key type 2 diabetes relevant enzymes and glycemic index

Phenolic compounds as agro-industrial by-products have been associated with health benefits since they exhibit high antioxidant activity and anti-diabetic properties. In this study, polyphenol-rich extract from pistachio green hull (PGH) was evaluated for antioxidant activity and its ability to inhibit α-amylase and α-glucosidase activity in vitro. The effect of PGH extract powder on in vitro starch digestibility was also evaluated. The results showed that PGH had stronger antioxidant activity than Trolox. The inhibitory effect of PGH extract against α-amylase from porcine pancreas was dose dependent and the IC50 value was ~174μgGAE/mL. The crude PGH extract was eight times more potent on baker yeast α-glucosidase activity (IC50~6μgGAE/mL) when compared to acarbose, whereas the IC50 value of PGH extract against rat intestinal maltase activity obtained ~2.6mgGAE/mL. The non-tannin fraction of PGH extract was more effective against α-glucosidase than tannin fraction whereas the α-amylase inhibitor was concentrated in the tannin fraction. In vitro starch digestibility and glycemic index (GI) of pasta sample supplemented with PGH extract powder (1.5%) was significantly lower than the control pasta. The IC50 value of PGH extract obtained from cooked pasta against α-amylase and α-glucosidase was increased. These results have important implications for the processing of PGH for food industry application and therefore could comply with glucose control diets.

Effect of gamma irradiation on the extraction yield, antioxidant, and antityrosinase activities of pistachio green hull extract

In this study, the antioxidant activity and tyrosinase inhibitory of non-irradiated and irradiated pistachio green hull (PGH) extracts were investigated. After irradiation of PGH by different doses of gamma ray (0, 10, 20, 30 and 40kGy), their phenolic compounds were extracted by water. Antioxidant activities of extracts were examined by DPPH• and FRAP methods. The results showed that irradiation not only do not have negative effects on antioxidant activity but also it can increase the amount of total phenolic compounds of water extract in comparison with non-irradiated sample. Water extract of irradiated PGH at the dose of 30kGy, showed the highest antioxidant activity in the DPPH° test with EC50 equal to 289.0 ± 1.2µg/ml. Irradiated (30kGy) and non-irradiated water extracts had the highest antityrosinase activities with IC50 of 10.8 ± 1.1 and 11.9 ± 1.2µg phenolic/ml, respectively. In addition, it was found that the water extract of irradiated PGH can prevent enzymatic browning in sliced raw potatoes. According to the antityrosinase potential of PGH extract, it may be suggested as an antibrowning agent in some foodstuffs or cosmetic products.

Optimization of pectin extraction from pistachio green hull as a new source

In this paper, the influence of pH (0.5–2.5), temperature (50–90°C), extraction time (30–150min) and liquid/solid ratio (10–50v/w) on the acidic extraction yield and degree of esterification (DE) of pistachio green hull pectin were studied by using central composite design. The results indicated that the yield and DE of pectin ranged from 7.31 to 19.02% and 26.00 to 53.01%, respectively. The optimization of pectin extraction condition showed that the optimal condition was pH of 0.5, temperature of 90°C, time of 30min and liquid/solid ratio of 50 v/w. In this condition, the experimental yield (22.1±0.5%) was fine accord among predicted yield (23.42%). Also, under the optimal extraction condition, the galacturonic acid content of pectin was about 65%. The FTIR spectrum showed that the pectin extracted under optimal condition is rich from polygalacturonic acid.

Interaction of phosphorus and pistachio green hull on some growth characteristics and nutrients in pistachio (Pistacia vera L.) seedlings

Interaction of phosphorus and pistachio green hull on some growth characteristics and nutrients in pistachio (Pistacia vera L.) seedlings

Removal of cyanide from wastewater by adsorption onto pistachio hull wastes: Parametric experiments, kinetics and equilibrium analysis

Many waste materials have been evaluated for their efficacy in removing different classes of contaminants from water and wastewater in order to improve the cost-effectiveness of adsorption. In the present study, pistachio green hull wastes were investigated as a potential adsorbent for the removal of cyanide from a synthetic wastewater. The effects of a selection of the most significant parameters (pH, adsorbent dose, cyanide concentration and contact time) were initially evaluated based on the percentage of cyanide removed from the wastewater. At an optimum pH of 10, over 99% removal of 100 mg/L cyanide was obtained for an adsorbent dose of 1.5 g/L after a 60 min contact time. Kinetic evaluation indicated that the adsorption of cyanide ions onto the pistachio hulls clearly followed the pseudo-second order rate reaction. The equilibrium assessment illustrated that the Langmuir model is the best fit for the experimental data, which attains a maximum adsorption capacity of 156.2 mg/g. The sorption of cyanide ions onto the introduced adsorbent was inferred to be a chemosorption process with intraparticle diffusion as the most important step controlling the overall process rate. Accordingly, the pistachio hull waste is introduced as an efficient and low-cost adsorbent for removal of different concentrations of cyanide from water and wastewater.

Antioxidant, anti-microbial and antimutagenicity activities of pistachio ( Pistachia vera) green hull extract

Antioxidant, anti-microbial and antimutagenicity activities of pistachio ( Ahmadaghaei variety) green hull extracts (crude and purified extracts) were studied. At first, different solvents were compared for determining of the best solvent for extraction of phenolic compounds from pistachio green hull. Water and acetonitrile with 49.32 and 6.22 (mg of gallic acid equivalents/g sample) were the best and the worst solvent in the extraction of phenolic compounds, respectively. The antioxidant capacity of crude and purified extracts were assessed through ABTS assay, DPPH assay and β-carotene bleaching (BCB) method. A concentration-dependent antioxidative capacity was verified in ABTS, DPPH assays and BCB method. The anti-microbial capacity was screened against Gram positive and Gram negative bacteria, and fungi. Aqueous and purified extracts inhibited the growth of Gram positive bacteria; Bacillus cereus was the most susceptible one with MIC of 1 mg/mL and 0.5 mg/mL for the crude and purified extracts, respectively. The results of antimutagenicity test showed that phenolic compounds of pistachio green hull have antimutagenicity activity against direct mutagen of 2-nitrofluorene. The results obtained indicate that pistachio green hull may become important as a cheap and noticeable source of compounds with health protective potential and anti-microbial activity.

CHEMICAL COMPOSITION AND RHEOLOGICAL CHARACTERIZATION OF PISTACHIO GREEN HULL'S MARMALADE

ABSTRACT This research aimed to study the effect of different levels of pistachio green hull (40–60%) and pectin (0–0.4%) on the flow characteristics of pistachio green hull's marmalade. It was found that pistachio hull's marmalade behaved as a pseudo‐plastic fluid. Seven models were used to describe time‐independent behavior of samples. To evaluate the ability of this models, two statistical parameters namely; R2 and root mean square error were used and finally power‐law model was found to be the most appropriate to fit the flow curves of pistachio hull's marmalade. Overall, the results showed that increasing the percent of pistachio hull increased the consistency coefficient in the range of 1.9–121 Pa·sn and apparent viscosity in the range of 0.67–7.95 Pa·s, whereas it decreased the flow behavior index in the range of 0.82–0.28. The change of flow behavior index and consistency coefficient with pectin did not follow a descriptive trend.PRACTICAL APPLICATIONSRheological properties of semisolid foods are important for quality control and process engineering calculations. Pistachio hull's marmalade is a semisolid gel made from puree of pistachio green hull, sugar, acid and pectin, which can be used in different formulations such as cake and cookies. Regarding the rheological data of marmalades in literature, comparisons in absolute terms do not provide useful information, possibly because of two reasons. Due to their complex mathematical geometries, some viscometers might not allow shear rate calculations and, hence, can only produce comparative rather than absolute flow behavior data. Another reason could be the differences in the production method or raw material used. Even very minor changes in composition or processing variables can dramatically influence the rheological properties. The knowledge obtained in this work will enable the pistachio processors to increase the efficiency of the design and quality control throughout the processing of this new product.