Showing 5 results for erfani moghadam
Volume 14, Issue 64 (6-2016)
Abstract
The postharvest life of bottom mushroom is limited due to bacterial attack and enzymatic browning. This study was carried out in order to increasing the storability of mushroom, by antibacterial and anti-browning components. For that, the mushrooms were treated by oxalic and citric acids at concentration of 1.5 and 2.5 mM, hydrogen peroxide at concentration of 1 and 2.5%, ascorbic acid at concentration of 1.5 mM and calcium chloride at concentration of 1% as dipping for 2 min, and then treated mushrooms were packed in cellophane and stored at 4°C. Weight loss, marketability, electro leakage (EL) and bacterial colony forming unit (CFU) were measured after 8 and 16 days. According to the results, calcium chloride, ascorbic acid and hydrogen peroxide controlled browning as compared to control. However, oxalic and citric acids, despite reducing microbial load, did not show any positive effects. Calcium chloride by reducing weight loss, reducing EL and reducing bacterial load, ascorbic acid by reducing EL and reducing bacterial load and peroxide hydrogen by reducing bacterial load tended to increase postharvest life of bottom mushroom.
Volume 19, Issue 127 (September 2022)
Abstract
In order to evaluate the quality and quantity of some important commercial Iranian pomegranate cultivars, in the climatic conditions of Yazd, the fruits of 12 cultivars including: Ardestani Mahvalat, Bejestani, Shishekap Ferdows, Naderi Badroud, Qajaq Qom, Gel Tafti, Shirin Shahvar, Robab Neyriz, Malase Yazdi, Malase Saveh, Malase Yousefkhani and Khazar Bardaskan were harvested at commercial maturity stage and were evaluated for important quantitative and qualitative traits. The results showed, there were significant differences among the cultivars in terms of fruit weight, skin and aril color properties (CIE L *, a *, b * and Hugh angle), soluble solids content, titratable acidity, antioxidant activity and anthocyanin content. Meanwhile, the highest fruit weight was measured in Shirin Shahvar cultivar, this cultivar also had the lowest titratable acidity and the highest taste index among the cultivars, and also this cultivar showed a bright color, however, the brightest color among the cultivars was observed in Naderi Badroud. Based on the skin and aril color properties, anthocyanin content and fruit taste, Malase Yazdi was the best among the cultivars. However, cultivars such as Shishekap Ferdows, also showed good quality characteristics. Also the correlations between traits was investigated and significant relationships were observed between color properties and amount of anthocyanin or between antioxidant capacity and amount of phenol or amount of anthocyanin.
Volume 20, Issue 136 (June 2023)
Abstract
Abstract
Increasing and improving the stability of colors in food during processing and also controlling the release until consumption is one of the most important issues and challenges in the use of natural colors in food. Hence, the objective of this study was to produce phytocyanin-containing nanoliposomes coated with chitosan by thin-layer ultrasonic hydration method to increase the stability of phycocyanin and to investigate its physical properties and encapsulation efficiency during storage. In this study, phycocyanin was coated with different concentrations of chitosan (0, 0.1, 0.2, 0.4, and 0.6 mg/mL) and stored at two temperatures (4 and 25° C) for 28 days. Then, to determine the best concentration of chitosan for coating the nanoliposomes, encapsulation efficiency, particle size, and zeta potential tests were performed. The results revealed that by increasing the concentration of chitosan to more than 0.2 mg/mL, no significant change in encapsulation efficiency was observed (p> 0.05). The sample without chitosan had the lowest particle size which was not a significant difference from samples containing 0.2 and 0.4 (p> 0.05). Increasing chitosan in the coating of nanoliposomes has led to increased zeta potential. Finally, a sample containing 0.2 mg/mL chitosan was selected as the best sample. Findings from analyses performed during the storage of nanoliposomes showed that nanoliposomes containing phycocyanin, which did not have any chitosan coating, had the highest encapsulation efficiency. On the other hand, it was found that with increasing storage temperature and storage time, the encapsulation efficiency decreased but the particle size increased. The lowest zeta potential of the samples was related to the phycocyanin-free nanoliposome sample which did not change significantly until the 21st day of storage at 4 °C. Scanning electron microscopy (SEM) images of the samples also confirmed the results of particle measurements.
Volume 20, Issue 141 (November 2023)
Abstract
In fish processing industries, 50-70% of primary fish are produced as waste, while they are rich sources of protein and essential amino acids. The optimal use of these wastes and the production of compounds with high added value that have significant health-giving properties is one of the important challenges of fish processing industries. In this research, the effect of hydrolysis conditions (time: 30-300 minutes and enzyme concentration 0.5-3%) and type of protease (pepsin and trypsin) on the degree of hydrolysis and antioxidant properties (DPPH radical scavenging activity, Fe chelating activity, No radical scavenging activity, total antioxidant capacity and Fe reducing power) of hydrolyzed protein obtained from Skipjack viscera were evaluated using response surface methodology. The results showed that the optimal conditions for the production of hydrolyzed protein with the maximum antioxidant properties with pepsin and trypsin enzymes were respectively: hydrolysis time of 179.09 and 143.62 minutes and enzyme concentration of 2.63 and 1.94 %; In this condition, the degree of hydrolysis of the hydrolyzed proteins resulting from the activity of trypsin was calculated to be higher than that of pepsin. Comparing the antioxidant properties of the hydrolysates obtained from the two enzymes used showed that the hydrolyzed protein obtained from trypsin had a stronger antioxidant potential than pepsin. Therefore, it can be stated that the hydrolyzed protein of the Skipjack viscera using trypsin enzyme as a health-giving supplement and with high added value can be used in the production of functional food products and health supplements for athletes and elderly people.
Volume 20, Issue 143 (January 2023)
Abstract
The seeds of Cucurbitaceae plants (pumpkin, melon, etc.) are one of the rich sources of protein. Proteins are one of the most important nutritional sources for humans. Enzymatic hydrolysis of pumpkin seed protein by using microwave pretreatment leads to the production of hydrolyzates with bioactive properties, including antioxidant activity. The use of microwave pretreatment causes changes in the 3D structure of proteins, It opens the 3-dimensional structure of the protein and accelerates the access of the enzyme to the peptide bonds. Therefore, the use of microwave pretreatment is a suitable method to save time and enzyme concentration which are used in enzymatic hydrolysis. In this study, The solution of pumpkin seed protein concentrate was exposed to microwave energy with a power of 500-900 W for 30-90 seconds and it was used as a substrate solution in enzymatic hydrolysis experiments. Enzymatic hydrolysis by pancreatin, with the concentration of 0.5 to 2.5% compared to the protein substrate, was performed in the time from 20 to 190 minutes, at the optimum temperature and pH of pancreatin, in order to produce hydrolysates with antioxidant potential. Antioxidant power was measured by using DPPH radical scavenging activity methods, total antioxidant activity (Absorbance at 695 nm) and iron chelating activity. The highest amount of antioxidant activity by using microwave pretreatment was in 105 minutes and the ratio of 1.5% E/S and the optimal conditions that provided by the software to achieve the maximum iron chelating activity (95.5%), DPPH radical scavenging activity (51.5%) and total antioxidant (Absorbance at 695 nm) (0.976), was in 102 minutes and the ratio of 1.5% E/S of which 89.5% corresponded with the obtained results.