Pistachio hull, as the dominant component of pistachio processing wastes, is a source of phenolics with antioxidant properties. Extracting these compounds from pistachio wastes has recently attracted a lot of attention. The current study aimed to identify the optimal conditions for extracting phenolics from pistachio hulls. Firstly, some parameters such as different sample to solvent ratios (1:10, 1:20, and 1:40), extraction temperatures (25, 45, and 65°C), and duration times (1, 2, and 3 h) were evaluated under extracting solvent of water. The content of total phenolics and antioxidant activity were determined using spectrophotometric methods. The results indicated that the highest phenolics (~35 mg g-1) were extracted at 2 h extraction time, 65 °C, and the sample to solvent ratio of 1:10 (optimum condition by the solvent of water). Secondly, other organic solvents of ethanol, methanol, and acetone 50% were evaluated to identify the best solvent under optimal conditions. All of these organic solvents were more efficient than water in extracting total phenolics (with antioxidant property) from pistachio hulls. However, the highest amount of total phenolics (~47 mg g-1) was extracted by ethanol. Optimizing the extraction of phenolic compounds from pistachio hulls would be important in terms of reducing human and environmental risks caused by the waste accumulation, as well as producing naturally beneficial compounds and using them instead of synthetic antioxidants in the human diet. تفاصيل المقالة

Pistachios (one of 50 healthy foods) are essential for human health. The ripening stage is of great importance for food processing, as the chemical composition of this fruit is heavily influenced by its maturity level. For instance, as premature pistachio has unique green color, it can be used in desserts, sauces, ice creams, and chocolates, while mature pistachios often used as snacks. Considering that the nutrients in the pistachio kernel are dependent on various factors, especially environmental conditions, determining the amount of these compounds during the ripening stages of the pistachio kernel can considerably contribute to the appropriate harvest time and increase the duration of its storage period. Biochemical compounds such as carbohydrates, fats, and proteins are less affected by growth but may affect pistachio kernel taste and its nutritional value and health. The highest amounts of carbohydrates, fats, and proteins are available at the time of optimal harvesting when the hull is fully ripe. Phenolic compounds and antioxidant activity of pistachio decrease during ripening, and oil and fatty acid levels increase with the ripening period. In the case of the color parameter, the L factor decreases during the ripening period, and the a and b factors increase. Different stages of ripening have a significant effect on pistachio compounds. Nutrients in pistachio kernel are dependent on various factors that their diagnosis in different stages of growth contributes considerably to harvesting at the right time and increasing the storage period of this product. تفاصيل المقالة

The economic importance along with the high nutritional value of pistachio has necessitated further research on this agricultural product. Its contamination with various microorganisms causes several problems for the production, consumption and export of pistachio every year. Pistachio as a fatty nut is very susceptible to fungal and bacterial contamination and thereby, its shelf life would be reduced. Peracetic acid is a strong oxidizer which can rapidly remove a wide range of microorganisms and is also environmentally safe. In this research, pistachio seeds were firstly treated with different concentrations (0, 1, 2 and 2.5%) of peracetic acid for 0.5, 1, 1.5, 2 and 5 min. Then the growth of fungi and bacteria were evaluated. The results indicated that 2% peracetic acid for 0.5 min led to 99% reduction in contaminating microflora . In the next step, the most common microflora contaminating pistachio seeds were detected and exposed to different concentrations of peracetic acid for 0.5, 1, 1.5, 2 and 5 min. The results showed that 1% peracetic acid for 0.5 min inhibited the growth of the dominant microflora more than 99%. Peracetic acid treatment in the tested range had no significant effect on lipid content but reduced peroxide value. Therefore, disinfection of pistachio product with a concentration of 1-2% peracetic acid in the washing basins of pistachio processing terminals may be an applicable approach to inhibit their microbial (bacteria and fungi) contamination up to 99% and improve their quality before introducing to the market. However, this idea requires further field research. تفاصيل المقالة

Pistachio green kernel, is obtained by removing the red testa of around the whole kernel. In this study, the suitable peeling conditions for removing the testa of the kernel were determined using hot water in five termperature levels of 75, 80, 85, 90, and 95°C and diffetent hot water immersion times of 2, 4, 6, 8, and 10 minutes in riped and unripe samples. Quality factors including the number of pistachio green kernels with remained red testa, free fatty acids, and peroxide value were measured at 3 and 6 months after peeling. Sensory evaluations (including appearance, color, taste, and texture) of the best treatments from the previous stage, were measured by 10 trained panelists. Peeling performance were not good using temperatures of 75 and 80°C in both riped and unripe samples. Peeling performance of 100%, was obtained at 85 and 90°C (6, 8 and 10 min) and 95°C (2, 4, 6, 8 and 10 min) kernel immersion in hot water in riped and unripe cultivars. The qualitative factors, free fatty acids and peroxide value, has have increased in both riped and unripe samples during storage. After 6 months of storage, the lowest peroxide value was observed at 90°C (10 min immersion in hot water) and 95°C (2, 4, 6, 8 and 10 min immersion in hot water). The minimum free fatty acid, was observed in riped ripe samples at 90° C (10 min immersion) and in the unripe samples at 95°C (2 and 4 min immersion). According to the comments of trained panelists, the significant differences between treatments were not observed in terms of the sensory characteristics such as taste, texture, color, and appearance at 5% level. In general, with respect to the performance of peeling, free fatty acids, peroxide value, and sensory evaluation, temperature of 95°C (2 min kernel immersion in hot water) can be used for peeling of riped and unripe samples. تفاصيل المقالة

Roasted pistachios are among the most delicious nuts in the world. In addition to their pleasant taste, they have significant nutritional and antioxidant effects. This study aims to evaluate the nutritional, sensory, color, and texture attributes of roasted pistachio nuts using fixed and rotary methods at 160 °C during three storage times of 0, 3, and 6 months, at the ambient temperature (20±2°C). The results showed that the moisture percentage of the samples decreased and increased after the roasting process and during the 6-month period of storage, respectively. The available fat percentage of the samples showed no significant change after roasting and storage. The protein content of the roasted samples declined because of the Maillard reaction. Although carbohydrates are less sensitive to temperature than proteins, after the roasting process, the sugar and starch content of the pistachio nuts decreased. Due to the thermal process, the texture was more fragile, and the hardness of the samples decreased. Because of the caramelization and browning reactions that happened during the roasting process, the color of the samples turned dark and less green. These changes intensified after the 6 months of storage. According to the results, quality changes were not significant in the two methods of roasting and storage (p≤ 0.05). Also the temperature and storage time had no specific destructive effect on the nutritional, sensory, color and texture properties of roasted pistachios. Therefore, the use of these two methods of roasting at 160℃ for 15 minutes is recommended. تفاصيل المقالة

Pistachio butter is one of the pasty products made from pistachio kernels. This study investigated color characteristics, peroxide value, fat, protein, and carbohydrate content, and sensory evaluation of pistachio butter enriched with Spirulina algae (0, 5, and 10%) during three months of storage at 20°C. With increasing the percentage of the algae, the sample with 10% of the algae showed the highest protein content (around 25.4%). The highest and lowest fat content was observed in the control and the sample containing 10% algae, respectively. The lowest peroxide value (0.73 meq kg-1) was observed in the sample containing 10% algae compared to others. The level of carbohydrates did not change significantly in all three specimens during storage. Sensory evaluation for taste, sweetness, color, spreadability, mouthfeel, and texture showed that the sample without algae and the specimen containing 5% algae did not differ much. With increasing the algae level to 10%, the sensory evaluation had a significant drop, and in some cases, there was a decrease in the score. The color evaluation of the samples showed that with increasing the algae level, the greenness of the specimen increased, a value decreased, and b value did not show a significant change. Overall, The amount of algae recommended in the pistachio butter formulation is 5%. تفاصيل المقالة

In this study, different methods for shell splitting and the effect of freezing prior to drying on shell splitting percentage of pistachio were investigated. A completely randomized design was used to investigate the effects of different freezing temperatures (0, -6, -12 and -18°C), different drying temperatures (80, 90 and 100°C) and different cultivars (Akbari and Kalehghouchi) on shell splitting percentages. The results showed that both freezing and drying temperature significantly (p ≤ 0.05) affected the splitting of closed shells into open shells. The effect of cultivar was insignificant. The highest shell splitting percentage (16.56%) was observed with a freezing temperature of -18°C and when a drying temperature of 100°C was used. Freezing and drying temperatures did not significantly increase the number of isolated kernels. However, in most treatments, isolated kernels were observed. Despite the isolated kernels, The shell splitting percentage did not decrease in any of the treatment groups. The results showed that freezing prior to drying can increase the percentage of split pistachio nuts. Thus, by increasing the difference between the temperature of the freezing and the temperature of drying, the percentage of split pistachio increased. تفاصيل المقالة

Pistachio powder is a product used today in confectionery, ice cream, pistachio paste and other foods. Considering the higher rate of spoilage and oxidation in pistachio powder, developing methods to increase the shelf-life of this product is therefore important. In this study the effect of freezing and vacuum packaging on the quality characteristics of pistachio powder during storage was investigated. The effect of packaging conditions (vacuum or air packaging), storage temperature (25°C, -18°C) and storage time (0, 1, 2, 3 and 4 months) on chemical (free fatty acids, acid value, peroxide value), physical (moisture content and color indexes of L*, a* and b*), and sensory (odor, taste, color, texture and overall acceptance) characteristics were studied. The results revealed that the peroxide value, acid value and free fatty acids in frozen and vacuum containers were lower than those packed without vacuum at room temperature. The results of sensory evaluation indicated a significant difference (p< 0.05) in samples.The best quality characteristics in terms of odor, taste, and overall acceptance belonged to the pistachio powder packed in vacuum and frozen conditions; however, in terms of texture , the containers packed and stored in ambient conditions showed better results. In all cases, the quality of pistachio powder decreased during the storage period. There was no significant difference between samples in moisture content, color indices of L*, a*, b* and sensory evaluation of color. It was generally found that packaging under vacuum and freezing could increase the shelf life of pistachio powder. تفاصيل المقالة