Fresh Pistachio Research Articles

Spraying glycine betaine on fresh pistachio fruits (Pistacia vera L.) for preservation in cold storage

Oxidative stress occurs during storage, often leading to a decrease in fruit quality and subsequently reducing its marketability. In this investigation, the ability of glycine betaine (GB) to extend the quality and storage of fresh pistachios stored in cold conditions was evaluated. The independent variables in this study were the concentration of GB (0, 5, 10 and 15 mM) and storage period (at harvest, 25, 50, and 75 days after harvest). Over time, the chlorophyll and carotenoid content of both kernels and hulls, as well as phenolics, flavonoids, antioxidant activity, taste, aroma, appearance of shells and hulls, firmness, and overall weight, tend to decrease. However, glycine betaine (GB) significantly prevents these reductions. GB effectively countered the rise in malondialdehyde, ion leakage, and hydrogen peroxide levels in kernels over time. In GB-treated samples, anthocyanin levels initially increased when comparing harvest time in both kernels and hulls, but subsequently decreased. GB enhanced peroxidase activity and suppressed polyphenol oxidase activity. However, contrary to expectation, GB reduces phenylalanine ammonia lyase activity. Overall, higher GB concentrations lead to a more pronounced effect. Based on the results, GB, particularly at a concentration of 15 mM, is recommended for preserving fresh pistachios during cold storage.

Chemical composition and antibacterial activity of essential oils extracted from fresh and dried aerial parts of Rosmarinus officinalis L. Pistacia lentiscus L. and Thymus vulgaris L. from Algeria

ABSTRACT The aim of this study was to determine the chemical composition and antibacterial activity of essential oils (EOs) extracted from local plant by steam distillation from the aerial parts (fresh – dried) of rosemary (Rosmarinus officinalis L.), pistachio (Pistacia lentiscus L.) and thyme (Thymus vulgaris L.). Monoterpenes were identified by GC-MS as main compounds, namely 1,8-cineole (34.5–35 %), α-pinene (36.2–36.6 %) and thymol (42.2–42.1 %). Our results showed that EOs tested had antibacterial effects at different levels, with MICs ranging from 1.56 to 6.25 mg.mL−1. Fresh rosemary EO was synergistic against Pseudomonas aeruginosa ATCC 27,853 when combined with dried rosemary EO and fresh pistachio EO, with MICs half those of oils alone (from 6.25 to 3.12 mg.mL−1). In addition, antagonistic, additive and indifferent effects were recorded at 1 %, 3 % and 93 %, respectively. Our findings provide new data on antimicrobial potential of local plants and possibilities of their use as food preservatives.

Spraying zinc oxide nanoparticles on pistachios (Pistacia vera L.) for preservation in cold storage

ABSTRACT The ability of zinc oxide nanoparticles to extend the shelf life of fresh pistachios in polyethylene packages in cold storage was evaluated. Independent variables were the type and concentration of the disinfectant (0.5%, 1%, 1.5%, and 2% nano-ZnO and 2% peracetic acid) and storage time (at harvest, 25, 50 and 75 days after harvest). Aflatoxin was not detected in the kernels of the disinfectant treatments after storage. A decrease occurred in firmness, chlorophylls and carotenoids in hulls and kernels over time. Phenolics and flavonoids of kernels decreased, parallel to a decrease in weight. Nano-ZnO (2%) prevented this reduction well. In hulls and kernels, nano-ZnO (2%) revealed the highest anthocyanin. Antioxidant activity in kernels remained stable or even increased in response to ZnO (1.5%) on day 75. All ZnO treatments prevented ion leakage while limiting hydrogen peroxide and malondialdehyde production in hulls. Peracetic acid reduced polyphenol oxidase activity on 75th day. ZnO (1% and 1.5%) and peracetic acid increased phenylalanine ammonia lyase activity. On 75th day, ZnO-treated samples had higher peroxidase activity. All ZnO treatments, especially 1.5% and 2%, prevented the loss of quality in hulls, shells, taste, and aroma. Nano-ZnO (2%) can be recommended for fresh pistachio preservation in cold storage.

Evaluation of storage potential of fresh pistachios under different forms of exposure to storage

Evaluation of storage potential of fresh pistachios under different forms of exposure to storage

Characterizing the antioxidant and antifungal properties of nano-encapsulated pistachio hull extract in fenugreek seed gum to maintain the quality and safety of fresh pistachio.

The quality of pistachio, one of the export products of Iran, will be decreased during storage as a result of mold spoilage, toxins production, and oil oxidation. This study aimed to investigate the capability of pistachio hull extract (PHE) loaded in fenugreek seed gum (FSG):whey protein isolate (WPI) nanoemulsion to control oil oxidation, and fungi growth in fresh pistachio nut during storage at 4°C. The total anthocyanin and total phenolic content of the PHE were 125.44 μg/g and 675.18 mg/g, respectively. The DPPH radical scavenging activity of PHE at 100 ppm was higher than that of tert-butylhydroquinon (TBHQ). In comparison with other concentrations, 50 ppm showed the strongest antifungal activity against Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomius. All nanoemulsions have a mean size lower than 265 nm. The polydispersity index (PDI) of different nanoemulsions was lower than 0.3, and a negative zeta potential was observed. The encapsulation efficiency was higher than 67.0% and all nanoemulsions had spherical morphology. The pistachio nuts were coated with different coating solutions containing 0 and 100 ppm of PHE and stored at 4°C for 8 weeks. The results showed that the pistachio sample coated with a composite coating of WPI and FSG containing 100 ppm of PHE has a higher moisture content and lower changes in L*, a*, and b* indexes, oil oxidation, fungi development, and total mold and yeast count. This treatment exhibited higher overall acceptance than other samples at the end of storage time. The results of this study suggest the use of biodegradable coatings enriched with natural extracts that have high antioxidant and antifungal activities.

Inhibitory Effect of Ascorbic Acid in Enzymatic Browning and Preservation of Quality in Fresh Pistachios (Pistacia Vera L.)

Inhibitory Effect of Ascorbic Acid in Enzymatic Browning and Preservation of Quality in Fresh Pistachios (Pistacia Vera L.)

Probiotic-loaded seed mucilage-based edible coatings for fresh pistachio fruit preservation: an experimental and modeling study

In this study, Lallemantia royleana mucilage (LRM) based edible coating containing 1.5 × 108 and 3 × 109 CFU/mL Lacticaseibacillus casei XN18 (Lbc1.5 and Lbc3) was designed to improve the quality and shelf-life of fresh pistachio. The fresh pistachios were coated with LRM + Lbc and their physicochemical, microbial, and sensory properties were evaluated after 1-, 5-, 15-, 25-, and 35-day storage at 4 °C. By the end of storage day, in comparison to control, the presence of probiotic isolate in the edible coating (particularly LRM + Lbc3) led to a marked decrease in fungal growth (3.1 vs. 5.8 Log CFU/g), weight loss (6.7 vs. 8.1%), and fat oxidation (0.19 vs. 0.98 meq O2/kg), and preserved total chlorophylls (8.1 vs. 5.85 mg/kg) and phenols (31.5 vs. 20.32 mg GAE/100 g), and antioxidant activity (38.95 vs. 15.18%) of samples during storage period. Furthermore, LRM + Lbc3-coated samples had a probiotic number above the recommended level (6.85–9.29 log CFU/g) throughout storage. The pistachios coated with probiotic-enriched edible coatings were greatly accepted by panelists. In the next section, Gaussian Process Regression (GPR) was used for predicting some parameters including: weight loss, TSS, Fat content, PV, Soluble carbohydrate content, Viability, Total phenolic compounds, Antioxidant activity, Mold and yeast, Total chlorophylls, Total carotenoids, Color, Odor and Overall acceptance. The results indicated that, there is a good agreement between the actual and predicted data by GPR model and it can be used for similar situation to decrease the cost of laboratory tests and increase the respond of analysis.

Effect of Nanoencapsulated Pistachio Green Hull Extract in the Carboxymethyl Cellulose and Soy Protein Isolate Edible Coatings on Shelf‐Life Quality of Fresh Pistachio

Effect of Nanoencapsulated Pistachio Green Hull Extract in the Carboxymethyl Cellulose and Soy Protein Isolate Edible Coatings on Shelf‐Life Quality of Fresh Pistachio

Quality evaluation of fresh pistachios (Pistacia vera L.) cultivars coated with chitosan/TiO2 nanocomposite

Fresh pistachios are rich in dietary fiber, minerals and unsaturated fatty acids, but they have a short shelf life. This investigation examined the effect of pre-harvest foliar application with chitosan (500 and 1000 mg. L−1), nano-chitosan (250 and 500 mg. L−1), and chitosan/TiO2 nanocomposite (250 and 500 mg. L−1) coating films on the postharvest physiology and storage of fresh pistachios (Pistacia vera cvs. Akbari and Ahmad Aghaei) cultivar during storage at 4 ± 0.5 °C. It was found that, fresh pistachios' shelf life could by increased by up to 30 days by the use of chitosan/TiO2 nanocomposite coating for foliar application. The decay index of the composite coated fruits was 4–6 % lower than that of the control group, and after 50–60 days the bacterial contamination appeared in cultivars; respectively. The nanocomposite treatments reduced the fruits weight between 30 and 40 %, which was 15 % higher that of than uncoated fruits. The pre-harvest application of chitosan/TiO2 coating reduced microbial contamination, weight loss, phenylalanine ammonialyase (PAL) activity and saturated fatty acids, and increased unsaturated fatty acids, antioxidant properties, sensory properties, essential minerals, superoxide dismutase (SOD), quality indicators and shelf life. These results demonstrated that the chitosan/TiO2 (250 and 500 mg. L−1) coating film effectively preserved the nutrient composition, sensory quality, nutritional value, antioxidant capacity and shelf life of fresh pistachio.

Pre-harvest application of GABA and CaO delays senescence and maintains of physicochemical characteristics of fresh ‘‘Ahmad Aghaei’’ pistachio during cold storage

The present study was conducted to determine the effects of preharvest application of calcium oxide 1% (CaO), gamma-aminobutyric acid 20 mM (GABA), and the combined treatment of CaO and GABA on shelf life and quality of fresh pistachio in cold storage (at 4 ± 1 °C with 85 ± 5% RH) for 75 d. Post-harvest quality and biochemical characteristics of fruits were measured during 0, 25, 50, and 75 d of storage. The investigation results showed that with the increase in storage time, the hull and kernel firmness (63% and 75%, respectively) and kernel lipid (55%) decreased in treated fruits. Still, the phenolic compounds (45%) and antioxidant activity (10%) of the kernel, hull malondialdehyde (66%), and kernel and hull anthocyanin (71%) increased. Fruits treated with CaO 1% (contained the most kernel lipids and flavonoids and the lowest hull), kernel anthocyanin, and kernel carotenoids. As a result, CaO + GABA pre-harvest treatment was recognized as the best treatment by maintaining antioxidant properties, better overall acceptance, and a higher percentage of healthy fruits during storage. However, applying the treatment before harvesting in the orchard takes a lot of time, but water does not accumulate in the pistachio hull, and the treatment is better absorbed.

Physicochemical and quality characters of fresh pistachio (Pistacia vera L.) cultivars in response to chitosan/ZnO nanocomposite coating

This study was done to evaluate the effect of pre-harvest foliar application with chitosan (500 and 1000 mg L−1), Nano-chitosan (250 and 500 mg L−1), and chitosan/ZnO nanocomposite (250 and 500 mg L−1) coatings on the quality and shelf life of fresh pistachios of “Akbari” and “Ahmad Aghaei” cultivars during storage. The results showed that 250 and 500 mg L−1 of chitosan/ZnO coatings significantly affected the shelf life of pistachios up to 35 and 40 days, respectively; in addition, chitosan/ZnO nanocomposite in both cultivars reduced weight loss, aflatoxin contamination, decay, polyphenol oxidase and glutathione-peroxidase enzymes, peroxide value, free fatty acids, and improve firmness, sensory properties, protein, oil content, carbohydrate, antioxidant properties, anthocyanin, phenol, and flavonoid. These results indicated that using chitosan/ZnO (250 and 500 mg L−1) is a promising efficient, safe, and environmentally friendly method for preserving the quality of fresh pistachios. It reduces hull browning and minimizes post-harvest losses.

The effect of chitosan coating combined with cold plasma on the quality and safety of pistachio during storage.

Pistachios are one of the most important agricultural and export products of Iran. Fresh pistachio fruit has soft skin, is highly perishable, and therefore has a short life after harvesting, which has made traders and consumers have a great desire to increase the shelf life of this product. For this purpose, in this study, the effect of different concentrations of chitosan as an edible coating (0.5 and 1.5% w/v) and the duration of cold plasma treatment (60 and 120 s) were investigated during 180 days of pistachio storage. The effect of treatments on the shelf life of pistachio fruit was evaluated by determining moisture content, color components, peroxide value, total mold and yeast, hardness, aflatoxin content, and sensory evaluations. The results showed that the treatment with 1.5% chitosan coating and 120 s of cold plasma treatment preserved the hardness of the pistachio and the color indices in the best way (p < .05). Also, this treatment had the minimum number of peroxide, aflatoxin, and mold and yeast counts during the storage time. The treatments with chitosan coating and under plasma application did not cause any unpleasant odor or taste during the storage time. In conclusion, according to the results of this research, it was determined that the simultaneous use of chitosan coating and cold plasma treatment can potentially be used as a new approach for commercial applications and the export of fresh pistachios.

Enrichment of White Wheat Bread with Pistachio Hulls and Grape Seeds: Effect on Bread Quality Characteristics

In creating sustainable food systems, alternative uses of food waste and by-products as a source of phenolic compounds or dietary fiber in food formulations should be evaluated to reduce food losses and waste. In this study, wheat bread was fortified with agro-industrial by-products, namely, fresh pistachio hull (FPH), pistachio hull powder (PHP), fresh grape seeds (FGS), and grape seed powder (GSP), at different levels (0.5–4%). The effects of this enrichment on moisture content, crust and crumb color, specific volume, baking loss, total phenolic content, antioxidant activity, and textural properties were evaluated and compared with control bread. Fortification with pistachio hulls and grape seeds, especially in powdered form, improved the total phenolic content and antioxidant activity of the bread compared with the control bread. With the increase in the amount of PHP from 0 to 4.0%, the total phenolic content of the bread initially increased from 0.89 to 14.66 mg GAE/g dry weight and the specific volume decreased from 3.59 cm3/g to 2.91 cm3/g. Bread containing PHP showed a significant reduction in baking loss and specific volume, while the addition of FGS and GSP at a low level (0.5%) improved the specific volume. The brightness (L*) of the crumb and crust gradually decreased with increasing levels of all additives. The crumbs of the breads with PHP and FPH were characterized by lower hardness, while GSP and especially FGS had higher hardness. All enriched breads (except those with FGS) were more elastic and easier to chew.

Carcinogenic and non-carcinogenic risk assessment induced by pesticide residues in fresh pistachio in Iran based on Monte Carlo simulation.

This research is aimed at the analysis of 87 pesticides in 30 fresh pistachio samples prepared from stores in Iran by QuEChERS-ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The results showed at least one pesticide was in 67% of fresh pistachio samples. Kresoxim methyl residue was detected in 20 samples with average of 0.11mgkg-1; this average is 2.2 times more than maximum residue limit (MRL). Buprofezin was recognized in five samples with average of 0.17mgkg-1 was observed with 3.4 times more than MRL; hexaconazole and permethrin were recognized in three samples lower than MRL with an average residue of 0.030 and 0.028mgkg-1, respectively. In addition, potential non-carcinogenic and carcinogenic health risk assessments were evaluated using probabilistic methods performed with the Monte Carlo simulation algorithm. The order of pesticide ranking based on hazard quotient (HQ) was hexaconazole > buprofezin > permethrin > kresoxim methyl. Total HQ (HI) was 2.0E-4 and for children, 9.0E-4. Hence, it means fresh pistachio consuming maybe not have significant short-term health risks for consumer. Ranking based on cancer risk (CR) was hexaconazole > kresoxim methyl > metalaxyl > permethrin > buprofezin. However, total CR due to pesticide residues was not higher than 1E-6 value (1.09E-9); therefore, consumers were not at significant risk of carcinogenicity in this product.

Impacts of carboxymethyl cellulose-based coatings with calcium oxide and GABA on storage life and quality maintenance of fresh pistachio fruit

ABSTRACT The fresh in-hull pistachio fruit was sprayed with 1% calcium oxide (CaO), 10 mM w/v γ-aminobutyric acid (GABA), 1% carboxymethyl cellulose (CMC), and their combination (CMC+GABA+CaO) for 30 sec at room temperature. Spraying with distilled water was considered as a control. Following drying of fruits at room temperature, they were packed in perforated polyethylene terephthalate containers and kept under cold storage (at 2 ± 1 °C with 85 ± 2% RH) for 75d. Pistachios treated showed the lower weight loss, and the highest hull safety, taste, aroma, and overall acceptance than control. Total chlorophyll and anthocyanin of fresh pistachio kernel were preserved by combined treatment. Combined treatment reduced the PPO, POD, PAL activity and MDA content of the hull and maintained kernel phenolic compounds compared to other treatments. Besides these, the best effects were obtained with combined treatment, which maintained the physical, biochemical and visual characteristics of the fresh fruit for 50 days.

Effect of Packaging and Storage Temperature on the Population of Aspergillus section Flavi and Aflatoxin Production in Fresh Pistachios

Effect of Packaging and Storage Temperature on the Population of Aspergillus section Flavi and Aflatoxin Production in Fresh Pistachios

Cover Caption

July Online Cover: Clustered fresh pistachios, ready for packaging; uninfected samples of fresh pistachios in multilayer films containing both gas compounds at the end of storage time; respiration rate in different packaging; and contamination of control samples in PE and multilayer films at the end of storage time, from “The effect of packaging and storage time on quality of clustered fresh pistachio”, by Behjat Tajeddin and Ahmad Shakerardekani. p. 2943–2952.

The effect of packaging and storage time on quality of clustered fresh pistachio.

Pistachio is one of the valuable, very nutritious, and high-energy fruits that is mainly dried and used as a snack due to problems with storage. Therefore, to investigate on how to extend clustered fresh pistachios' shelf-life, the effects of various packaging and storage conditions on the pistachios are presented in this study. Thus, clustered in-hull fresh pistachios were packaged in: (a) Polyethylene film, 45µm in thickness; (b) polypropylene/polyethylene/polyamide/polyethylene/aluminum foil multilayer film, 90µm in thickness; (c) both films with alcoholic paper; in air, and under two gas mixtures of 88%N2 + 10%CO2 + 2%O2 and 83%N2 + 15%CO2 + 2%O2 . Samples were refrigerated at 5 ± 1°Cfor 3 months. Quality factors such as moisture content, weight loss, respiration rate, pH, texture, and appearance of the samples were monitored for fresh pistachio kernels and clustered pistachios. Data were analyzed in a completely randomized design using one-way analysis of variance. The results showed that the shelf-life of MAP samples drastically increased compared to the control (packages without gaseous and alcoholic paper). A comparison of means among the groups suggests that the multilayer bags of fresh clustered pistachios with a mixture of 83%N2 + 15%CO2 + 2%O2 for a 3-month storage period is a particularly effective treatment. PRACTICAL APPLICATION: It is the first time that fresh pistachio is packaged in clusters (bundle). It seems that the packaging of fresh pistachio clusters, in addition to the benefits mentioned in this paper has a psychological effect on the consumer in terms of the naturalness of this product and has added value due to being considered an organic, luxurious, and delicacy food product. Therefore, in this study, the active MAP method that includes the technique of injecting carbon dioxide, nitrogen, and oxygen into the packaging was used to investigate its effects on the properties and shelf-life of raw clustered pistachios for fresh consumption.

Impact of calcium and γ-aminobutyric acid (GABA) on qualitative attributes and shelf life characteristics of fresh in-hull pistachio during cold storage

Fresh in-hull pistachio fruit was sprayed with 10 mM w/v γ-aminobutyric acid (GABA), 2 % w/v calcium oxide (CaO), and their combination (GABA + CaO) for 3 min at room temperature. Spraying with distilled water was considered as control treatment. Following fruit treatment, they were left at room temperature to dry and then packed in plastic trays, wrapped with low density polyethylene (LDPE) and stored at 2 ± 1 °C and 90 ± 5% relative humidity for 45 d. The treated fruit showed lower weight loss and total color change (ΔE) than control fruit. CaO and GABA treatments also reduced the activity of hull polyphenol oxidase (PPO) and maintained antioxidant activity of kernel and anthocyanin content of kernel skin (integument) as well as phenolics in pistachio hull. Respiration rate and microbial activity of whole fruit was decreased by CaO and GABA treatments at the end of storage time. The highest effect was obtained with GABA + CaO treatment, which maintained the physical, biochemical and visual characteristics of fresh pistachio for marketing. Thus, combined CaO + GABA might be used as an innovative postharvest tool to maintain fresh in-hull pistachio quality.

Preharvest Application of Sulfur as Pesticide on Fresh Hull and Kernel of Pistachio (Pistacia vera L.)

In recent years, sulfur has been shown to be effective in controlling pistachio psylla. In this study, the effect of sulfur foliar application as psylla pesticide on fresh fruit and kernel of three cultivars of pistachio was determined and compared with two commercial pesticides. Refinery micronized and mineral sulfur were applied at two concentrations of 30 and 60 kg/1000 L of water. The quality of fresh pistachio hulls and kernels were investigated. In ‘Fandoghi’ cultivar, all sulfur treatments reduced the kernel moisture. The firmness and water activity of hulls and kernels were significantly affected. All sulfur treatments decreased hull lightness in ‘Fandoghi’, while it increased in ‘Akbari’ and ‘Ahmadaghaei’ cultivars. Reduction of hull chroma was observed in some cases in all cultivars. Hue of hulls was not affected by the treatments. Lightness, chroma and hue values of the testa of kernels were not affected in ‘Fandoghi’ and ‘Akbari’. In ‘Ahmadaghaei’, refinery micronized sulfur increased the testa lightness and hue and decreased chroma probably because of the softer texture of hull in ‘Ahmadaghaei’ which breaks more easily during harvest practice. Sulfur treatments positively influenced appearance and general acceptance of ‘Ahmadaghaei’ fruits. The taste and aroma of pistachios were preserved in most of treatments. High concentration (60 kg/1000 L) of both sulfur types enhanced the ethylene production in ‘Ahmadaghaei’ which was almost same as the unripe fruit because sulfur treatments reduced the percentage of unripe fruit. In ‘Ahmadaghaei’, refinery micronized sulfur treatments increased the respiration rate.