antioxidant activity

In the present study, the effect of different amounts of Baneh skin oil (0.05% to 0.5%) on the oxidative stability of refined sunflower oil during 8 hours of thermal process at 170 °C was investigated, which was 100 ppm of synthetic antioxidant TBHQ. used for comparison. Evaluating the results of various oxidative stability tests (peroxide value, anisidine value, totox value, Conjugated diene value and acid value) showed that the use of Baneh skin oil improved the oxidative stability of sunflower oil. The best conditions of oxidative stability were observed in sunflower oil containing 0.05% of Baneh skin oil, followed by the oil sample containing 0.1% of Baneh skin oil, both of which had a superior antioxidant effect than TBHQ. In order to better interpret the results of oxidative stability tests, the changes of tocopherol and polyphenolic compounds as two indicator antioxidant compounds were investigated during the thermal process. The results showed that there is no relationship between the changes of these compounds and oxidative stability tests. The sample containing TBHQ had the greatest protective effect on antioxidant compounds, which due to the creation of a peroxidative state caused by the increase of antioxidants, it decreased the oxidative stability of sunflower oil. Also, the investigation of changes in antioxidant activity during the thermal process with the help of two DPPH radical scavenging and Rancimet tests also showed that the sunflower oil sample containing 0.05% of Baneh skin oil had the best conditions, which was consistent with the results of oxidative stability tests. The results of the present research are very important because the oil of the Baneh skin oil was not pure at all compared to TBHQ.

Fenugreek with the scientific name (Trigonella foenum-graceum) is a hidden plant, and the fenugreek seed, which is the most important medicinal part of this plant, contains flavonoids, sesqui-terpenes, sterols, and mucilage fibers. In the present study, the aqueous-alcoholic extract of fenugreek seeds at four levels (zero, 0.2, 0.4 and 0.6%) on some physicochemical characteristics (pH, acidity, hydration and viscosity), the amount of phenolic compounds, The antioxidant activity and sensory properties (taste, texture, color and overall acceptance) of the enriched stirred yogurt were evaluated during 14 days of storage. The results of data analysis showed that the sample containing 0.6 percent has the lowest and highest pH and acidity indicators, respectively. Also, by increasing the storage time up to 14 days and decreasing the pH, the amount of water content of all the samples increased significantly (P<0.05). The results showed that with a significant decrease in the content of phenolic compounds during the storage period, adding fenugreek seed extract to the amount of 0.6% in a period of 1 and especially 7 days increased the antioxidant activity and then, up to the storage time of 14 days, the antioxidant activity was low in some samples and with a very slight change in some samples (P<0.05). Also, the highest and lowest values of viscosity were 3500 centipoise (the control sample on the first day) and 703 centipoise (the sample containing 0.6% on the fourteenth day) (P<0.05). Finally, by examining the results of sensory properties, the sample containing fenugreek seed extract was able to get an acceptable score from the sensory evaluators compared to the control sample. Among the types of enriched and control yogurt formulations, the sample containing 0.6% extract had the highest degree of desirability in terms of sensory properties when stored for 1 day.

One potential strategy to mitigate environmental stress on plants is the utilization of a shade net. Changes in the environmental conditions on shade net, particularly with regards to luminosity and temperature, will invariably result in alterations in the biochemical reactions and quality attributes of the product. In light of the advancements made in shade net technology in Iran, the current study was undertaken to explore the impact of the green shade net with 30 percent shading on the quality attributes of apricots, Rajab Ali cultivar, at the Shahrood Agricultural and Natural Resources Research and Training Center on 2021-2022. Various parameters such as fruit length, diameter, weight, percentage of total soluble solids, titratable acidity, color, vitamin C, total phenol, total antioxidant capacity, and texture firmness were evaluated on treatment and control samples and subjected to t-test analysis at a 5% significance level. The findings indicate that the average weight of fruits during full ripening was 48.31 and 78.58 outside (control) and inside (treatment) shade net respectively. The difference between the color of the samples inside and outside the canopy was significant. The value of a* in the control samples was higher than its value in the treatment samples. A significant difference was observed between the amount of total phenol and total antioxidant activity between treatment and control. Total soluble solids were 13.71% and 13.10% respectively in the control and treatment at the stage of fruit ripening. According to the results, the use of shade net until the end of fruit ripening on apricot trees (6 months), in addition to changing the quality characteristics, also causes late fruit ripening.

This research aimed to investigate the physical, mechanical, antioxidant, and antimicrobial properties of a smart nanocomposite film based on chitosan/ aloe vera containing hydrolyzed tomato seed protein. For this purpose, the hydrolyzed tomato seed protein was first prepared using the Alcalase enzyme under different time conditions (30, 60, 90, 120 minutes). Then, 5 edible films including nano-chitosan, nano-chitosan and aloe vera gel with different concentrations of hydrolyzed protein (0, 0.5, 1 and 1.5%) were prepared, and the film properties were evaluated. Based on the results of the hydrolyzed protein, the hydrolyzed protein had a high protein content and degree of hydrolysis. This protein also had a high content of hydrophobic amino acids (31.78%) and aromatic amino acids (11.74%). The mechanical test results of the films showed that increasing the protein concentration led to a decrease in tensile strength and an increase in elongation at break of the polylactic acid films. According to the physical test results, increasing the protein concentration did not have a significant effect on moisture and solubility, but increased water vapor permeability and turbidity (p<0.05). the hydrolyzed tomato seed protein had high DPPH radical scavenging activities and increasing the concentration had a positive effect on these parameters (p<0.05). These films also had high antimicrobial activity against pathogenic bacteria, with higher antimicrobial activity against Staphylococcus aureus than Escherichia coli. The nanocomposite film containing 1.5% hydrolyzed protein had the highest antioxidant and antimicrobial activity (p<0.05). This study showed that hydrolyzed protein can improve the physical and mechanical properties of chitosan/aloe vera based films. Specifically, films containing 1.5% hydrolyzed protein had better properties such as higher antioxidant activity and antimicrobial activity.

Gamma-aminobutyric acid (GABA) as a bioactive compound has a wide range of biologica activities. Therefore, functional foods enriched with GABA have been widely considered by consumers. Whey is the most important waste product of the cheese-making industry and is considered a rich culture medium for probiotics. Among the various methods of GABA synthesis, GABA biosynthesis by fermentation using probiotics has been proposed as the simplest and safest method. Therefore, the aim of this study is to improve GABA production by Lactobacillus brevis NCL912 in whey enriched with different concentrations of glutamic acid.

After preparing the culture medium from whey powder, different concentrations of glutamic acid (0, 250, 500, 1000 mg L-1) were added to it. Then, a suspension of Lactobacillus brevis NCL912 strain (containing 108 CFU/g) was inoculated into the whey samples and placed in an incubator at 37°C, and the antioxidant activity, total phenol, GABA, and bacterial viability were examined at 24, 48, and 72 h.

The results showed that with the passage of time, the antioxidant activity increased, but the total phenol and GABA levels increased up to 48 hours and then decreased up to 72 h .With the increase in the concentration of glutamic acid, the antioxidant activity and GABA levels both increased first and then decreased, but the total phenol level increased. The passage of time and the increase in the concentration of glutamic acid had no effect on survival. Based on the results, the lowest and highest levels of GABA were obtained for samples with concentrations of 0 mg L-1 -24 h (401 ± 1.1 mg L-1) and 1000 mg L-1 -72 h (591.3 ± 2.6 mg L-1). The results of the analysis of variance showed that the time factor had no significant effect on the level of GABA (P <0.05), but with the increase in the amount of glutamic acid, the level of GABA increased significantly (P ≥0.05). As the highest value was observed at a concentration of 1000 mg L-1. Based on the results of analysis of variance and comparison of means, no significant difference was observed in the overall comparison of samples in terms of antioxidant activity, total phenol, GABA, and viability (P < 0.05), but only in the sample treated with a concentration of 0 mg L-1 of glutamic acid after 24 h, the DPPH inhibition and viability were significant (P ≥ 0.05).

The results showed that the use of the respective strain in whey containing different concentrations of glutamic acid led to an increase in the amount of GABA. The samples also had better antioxidant activity, total phenols and shelf life. Therefore, whey can be used to prepare a probiotic fermented drink enriched with this bioactive compound.

Indigo plant (Indigofera tinctoria L.) is a forgotten plant that has many therapeutic properties such as antibacterial, antiallergic, liver protector and antioxidant. Solutions that can reduce the effects of late season drought in plants can be very beneficial. The use of biological stimulant is one of the efficient methods to adjust biological stresses. The aim of this study was to investigate the effect of salicylic acid and glycine betaine elicitors at different irrigation levels on some morphological and phytochemical indicators of Indigo plant. Indigo seeds was bought from Sabzineh Gostar Company, Chabahar. Then, it was grown in 1 Kg plastic pots containing a mixture soil of cocopeat: perlite: garden soil (with a ratio of 1:1:1). Then the pots were placed in the Phytotron device with night temperature of 22°C, daytime temperature of 28°C, 16 hours of light and 8 hours of darkness. This experiment was conducted as a factorial based on a completely randomized design with 15 treatments and three replications. The treatments examined in this research include irrigation at three levels of 50, 75, and 100% of crop capacity as the first factor and stimulants of salicylic acid (at two levels of 2 and 4 mM) and glycine betaine (at two levels of 50 and 100 mM) along with control (spraying with distilled water) was as the second factor. Irrigation treatments were applied after the plants entered the four-leaf stage based on the agricultural capacity of the soil and by weight method. The agricultural capacity of pot soil was calculated by weight method with the help of moisture meter (TDR). Foliage treatments with stimulants (salicylic acid and glycine betaine) were performed at the 4-leaf stage. After one growing season, morphological parameters such as plant height, number of branches, wet and dry weight of plant, root length and root weight were measured. The amount of photosynthetic pigments was measured with Arnon method, by spectrophotometer approach. The anthocyanin content of leaves was measured by acid methanol method. Proline content was also determined by Bates method with the help of ninhydrin reagent. The total phenolic content was measured by Folin Ciocaltio reagent, the total flavonoid content was measured by aluminum chloride colorimetric method, and the antioxidant activity was measured by DPPH free radical inhibition assay. The results showed that reducing irrigation (50% FC) reduced plant height, number of branches, plant fresh and dry weight, root length and root weight, chlorophyll, carotenoid, anthocyanin and flavonoid. on the other handand, increased proline, phenol and antioxidant activity. Foliar spraying of glycine betaine and salicylic acid increased the above parameters under normal and water deficit conditions. The positive effect of glycine betaine, especially the concentration of 100 mM, was higher compared to the positive effect of salicylic acid. The interaction effect of irrigation and stimuli showed that the highest height (1.6 cm), dry weight of plant (73.47 grams per plant), root length (8.75 cm), chlorophyll a (10.8) mg/g) and carotenoid (0.53 mg/g) was obtained with 100 mM glycine betaine treatment in 100% crop capacity irrigation and the highest amount of phenol (294.3 mg/g of gallic acid) and antioxidant activity (68.47%) was achieved with 100 mM glycine betaine treatment in 75% FC irrigation regime. According to the results of the present research, glycine betaine and salicylic acid, especially glycine betaine at a concentration of 100 mM, can act as a suitable stimulus to increase growth, produce secondary metabolites of the Indigo plant and deal with low negative effects of droght stess should be suggested.

Due to climate situation of Iran, there is a high diversity of garden species such as Blackberries. Blackberry is one of the most important sources of anthocyanin, antioxidant, phenolic and flavonoid compounds. The present study was conducted to investigate the variation of phytochemicals and photosynthesis pigments traits in Iranian blackberry genotypes. For this purpose, four genotypes of R. sanctus were selected from the blackberry collections of the faculty of agriculture of Shiraz University and examined in a randomized complete block design in two-years. Then, at three different sampling dates (June (Khordad), August (Mordad) and October (Mehr)), the samples were harvested from both leaves and stem organs and transferred to laboratory. Finally, samples extracts used for measurement of traits including, IC50, flavonoid, total phenol, anthocyanin, flavanone, chlorophyll (a, b and total) and carotenoids. Based on the results, there was a significant variation between the studied individuals for IC50 (33.17-72.95 (leaf), 101.07-139.68 (stem), total phenol (117.77-172.17 (leaf), 79.16-138.79 (stems), flavonoid (275.79-389.76 (leaf), 100.03-151.44 (stem), flavanone (35.30-54.06 (leaf), 30.38-54.17 (stem), anthocyanin (50.33-73.34 (leaf), 35.34-48.25 (stem), along with other traits. The highest antioxidant activity (minimum IC50), phenol, Flavonoid, flavanone and anthocyanin were observed in August sampling date and both stem and leaf organ. According to correlation and regression analysis, there was a significant and positive correlation between the amount of antioxidant and phenolic compounds. Over all, with increasing the temperature especially in August, the IC50 was decreased, which it could be due to an increase of other phytochemical traits. So, the increase of phytochemical composition could be a criterion of tolerance to the harsh environmental condition such heat stress in August. In this regard, Babolsar were selected as bets genotype in terms of studied traits and tolerant genotype to heat stress as well.

The crucial role of food in life has prompted a shift towards products that not only offer good quality and nutritional properties but also ensure the overall health of consumers. Probiotics, which are non-pathogenic microorganisms, can restore intestinal microbial balance when consumed in sufficient quantities. In this study, Limosilactobacillus fermentum ARD2 isolated from local yogurt was investigated for its probiotic properties. Various aspects of this strain were evaluated, including acid resistance (at pH levels of 2, 3 and 4), resistance to bile salts (at concentrations of 0.3, 0.5 and 0.7 %), antimicrobial activity using disk diffusion agar and well diffusion agar methods, resistance to common therapeutic antibiotics, evaluation of antioxidant activity, cell surface hydrophobicity, DNase enzyme activity, hemolytic activity, and biogenic amine and cholesterol absorption. The results of the acid resistance tests indicated that the viability of L. fermentum ARD2 increased as pH levels rose from 2 to 4, with a decrease observed over time at a constant pH over 3 hours. Growth was inhibited with increasing concentrations of bile salts. Antimicrobial testing revealed that the acidic and neutralized cell-free supernatant (aCFS and nCFS) had no significant antimicrobial effect on Escherichia coli, while nCFS showed no antimicrobial effect on Shigella dysenteriae. L. fermentum ARD2 exhibited resistance to Ciprofloxacin and was semi-sensitive to Penicillin and Nitrofurazone. The L. fermentum ARD2 showed considerable antioxidant activity, with DPPH and ABTS free radical inhibition rates of 41.40% and 43.60%, respectively. Additionally, it demonstrated the ability to reduce cholesterol absorption by 38.60%. The strain tested negative for DNase and hemolytic activities, and biogenic amine production was not observed. Based on these findings, L. fermentum ARD2 exhibits promising probiotic characteristics and could be utilized as a probiotic bacterium in food products.

In recent years, the demand for healthy functional foods has increased and food industry is trying to meet these new needs. This study aimed to assess the effect of different concentrations of green tea powder (GTP) on the physicochemical characteristics, sensory properties, antioxidant activity, and culture viability of probiotic ice cream over a 90-day storage period. Seven ice cream samples containing 0–3% GTP and Lactobacillus casei were produced and evaluated at 0, 30, 60, and 90 days of storage. Folin-Ciocalteu and diphenyl picrylhydrazyl (DPPH) methods were applied to determine the total polyphenol content and antioxidant property, respectively. The results showed that the titratable acidity, antioxidant activity, total polyphenols, viscosity, melting resistance, and viable count of L. casei increased with increasing GTP concentration (p<0.05). Also over time, there was no significant difference in viscosity and total solids, but the total phenol, antioxidant activity, and viability of probiotic bacteria decreased significantly (p<0.05). The results of the sensory evaluation revealed that the flavor and color of the samples containing 1.5 and 2% GTP had the highest scores (p<0.05). Samples containing 1.5 % GTP that had the highest score of color, flavor, and overall acceptability, high antioxidant activity and viable count of L. casei ≥ 107 cfu/g during storage could be introduced as a new product with health-promoting properties.

Urtica dioica L., commonly known as nettle is a perennial herbaceous plant that is widely distributed throughout the world. This plant is rich in antioxidant compounds and possesses anti-inflammatory, anticancer, and antiallergic properties. Therefore, the aim of this study was to determine the bioactive compound groups, total phenolic content, total flavonoid content, and antioxidant activity of aqueous leaf extract of nettle plant. Fourier-transform infrared spectroscopy (FTIR) was used for identifying the bioactive compound groups. Additionally, the total phenolic content was measured using the Folin-Ciocalteu method, the total flavonoid content was determined by the aluminum chloride colorimetric method, and the antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. The results showed that the aqueous leaf extract of nettle contained 59.83 mg GAE/g of total phenols, 29.44 mg QE/g of total flavonoids, and exhibited antioxidant activity with 66.47% and 81.32% inhibition of DPPH and ABTS radicals, respectively. This study demonstrates that the aqueous leaf extract of nettle is a significant source of natural antioxidants and can be considered as a suitable alternative to synthetic antioxidants in food and pharmaceutical industries.

Vitis vinifera subsp. Sylvestris, belonging to vitis family and is one of the indigenous plants of Iran, was collected from Miankalleh. In this research, different plant extractions (methanol, water, chloroform, ethyl acetate) were obtained from the leaf and fruit of wild grapes. The yield of extraction was determined. Also, the total phenol and total flavonoid content of different extracts were analyzed and the antioxidant activity of the extracts was assessed using DPPH (2, 2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing power) methods. Our investigation showed that the aqueous extract of leaf (14.35%) and fruit (12.71%) had the highest level of extraction yield. The total phenolic content of the fruit was higher than the leaf. Also, the methanolic extract had a higher total phenolic content than other extracts in leaf (2.9±0.25 mg/g) and fruit (12.3±0.1 mg/g).Regarding the total flavonoid content, the methanolic extract of the fruit with 9.7±0. 03 mg/g, had the highest level. Investing the antioxidant activity using DPPH assay revealed that the aqueous leaf extract with IC50 of 26.74±0.12 µg/ml had the best result. The methanolic extract of the leaf was more potent than other extracts in the FRAP assay. In conclusion, the phytochemical analysis of the leaf and fruit of wild grapes showed that the methanolic extract had the best performance.

Canola oil with high unsaturated fatty acids and nutritional value is susceptible to oxidation due to lipid oxidation. Lipid oxidation leads to a reduction of nutritional quality, sensory and safety characteristics of the vegetable oils. To retard lipid oxidation, the synthetic antioxidants are usually used in the vegetable oils. By increasing the public concern about health problems of synthetic antioxidants, the use of natural antioxidants is increasing. Lavender (Lavandula officinalis) is an evergreen plant native to the Mediterranean. The presence of linalool, linalyl acetate, 1,8-cineole B-ocimene, terpinen-4-ol, and camphor in lavender essential oil, make it a good natural antioxidant which could use in food industry. Therefore, in the current research, it was aimed to investigate the antioxidant effect of lavender essential oil on the stability of canola oil.

The lavender was bought from Golestan province and dried in room temperature. The lavender essential oil was prepared by hydro distillation of flower heads. Then, the phenolic compounds were determined using GC-MASS. The Total phenolic content (TPC), flavonoid content (TFC), and antioxidant activity (FRAP and DPPH) of lavender essential oil were evaluated. Then, lavender essential oil in concentrations of 200, 400, 600, 800, and 1000 mg/kg was added to the crude canola oil compared to canola oils without antioxidants and synthetic antioxidant TBHQ (100 and 200 mg/kg). Then, the samples were kept at 60 to 70 oC for 12 days. The analysis was done in an interval of 24 h for 12 days. Lipid oxidation of samples was determined by peroxide value, p-anisidine value, TOTOX value, and thiobarbituric acid each 24 h. analyses of Data were done by one-way analysis of variance (ANOVA) using SPSS software and the means were compared by the Tukey multiple range test.

 According to the GC-MS analysis, 1, 8-cineole (59.45 %), linalool acetate (32.48 %), linalool (6.31 %), and limonene (1.06 %) were identified as the major constituent of lavender essential oil. Also, Total phenol, flavonoid, FRAP and DPPH (IC50) contents of lavender essential oil were 71.55 mg GAE/g, 82.66 mg of rutin/100 g, 12.63 mmol H2SO4, and 55.88 mg/ml, respectively. According to the results, all lipid oxidation indexes were increased after twelve days of storage. In general, lavender essential oil was effective in retarding the oxidation of canola oil at a temperature of 70 oC. Also, the concentration of 1000 mg/kg of the essential oil had antioxidant activities similar to the TBHQ in 100 mg/kg concentration.

 It was showed that lavender essential oil, as a natural antioxidant, has the ability to react with the radicals resulting from the oxidation of lipids and causes the interruption of oxidation chain reactions and increases the time and decreases the rate of oxidation. As observed, the oxidation of canola oil in all samples, especially the samples without antioxidants or antioxidants to a lesser extent, increased significantly with increasing storage time. In general, lavender essential oil at L1000 concentration and also in some oxidation indices of lavender essential oil at L800 concentration has an effective role in preventing the oxidation of canola oils like synthetic antioxidant TBHQ.

Postharvest fungal diseases can limit the storage period and shelf life, and thus market life of fruit and vegetables, which results in serious economic losses worldwide. Despite the efficacy of synthetic fungicides in the control of postharvest decay, public concerns about chemical and toxic residues in food and the increase in drug-resistant strains of many pathogens indicate the need for development of new strategies. Coatings and packaging materials have been considered as another method for increasing the postharvest storage time of fruits and vegetables. Chitosan-based nano composites are proper alternatives to mitigate the negative impacts of conventional coatings and films on human and environmental health. Additionally, natural chitosan coatings and packaging incorporated with functional compounds decrease the postharvest losses of fruits and vegetables without changing their nutritive and sensorial properties. Therefore, the current research work was performed to investigate the effectiveness of chitosan and chitosan nanofiber on the quality and storability of strawberry fruit cv. Paros. 

This study was conducted in the form of a factorial experiment based on a completely randomized design with two factors and three replications. The first factor was treatments in 5 levels including dry control, distilled water, chitosan 0.5%, chitosan nanofibers 0.2% and chitosan nanofibers 0.5% and the second factor was storage time in 5 levels including: Zero, 5, 10, 15 and 20 days. The treatments were applied as a 2-minute immersion of the fruits in the prepared solution at ambient temperature (25 ° C), and the samples were stored after drying in plastic disposable containers at 4°C and relative humidity of 85 to 90%. At the end of the storage periods, the values of weight loss, pH of fruit juice, total soluble solids, titratable acidity, and firmness of fruit tissue, color indexes, total anthocyanin, total phenol content, vitamin C content, antioxidant activity and percentage of decay of the aforementioned treatments were evaluated. 

The results showed that at the end of the storage period, the 0.5% chitosan nanofiber treatment was able to maintain the TA value 77% higher than the control at same-day. Also, the TSS of 0.5% and 0.2% chitosan nanofiber treatments was lower than the control, which indicates a delay in the tissue softening of coated fruits due to a lower breakdown of sugars. On the 20th day of storage, the pH, TSS/TA, and the percentage of weight loss in the treatment of 0.5% chitosan nanofiber were lower than the control; the explanation for the rise in pH of control fruits is due to the decrease in organic acids and potential sugar conversion. The highest value of firmness between treatments was found in the 0.5% chitosan nanofiber treatment (3.11 Newton) after 20 days of storage. The semi-permeable surface of coated fruits may have contributed to fruit firmness persistence by limiting metabolic gaseous exchange (oxygen and carbon dioxide) across the coating barrier, followed by a decrease in metabolic activity and oxidizing enzyme effectiveness. The highest content of vitamin C, total phenol, and total anthocyanin were in the 0.5% chitosan nanofiber treatment, which showed a significant difference from other treatments. At the end of storage, the percentage of antioxidant activity of fruits in coating treatments including 0.5% chitosan nanofiber, 0.2% chitosan nanofiber, and 0.5% chitosan, 25%, 14%, and 5%, respectively, was higher than the dry control. Higher contents of color indexes including Lightness (L*), Redness (a*), yellowness (b*) and Chroma, and lower values of Hugh angle were observed in fruit coated with chitosan nanofiber. The percentage of decay in chitosan nanofiber-treated fruits (0.5% and 0.2%) and chitosan (0.5%) decreased by 61%, 55%, and 43% more than the control, respectively.

The present study found that using a 0.5% chitosan nanofiber coating was the most effective way to maintain the quality of strawberries during storage for up to 20 days. It allowed good preservation quality such as weight loss, decay, antioxidant activity, firmness, color, Vitamin C, anthocyanin content, and total phenolic compounds. However, 20 days is a sensitive period for the commercialization of strawberries, considering the normal time of 7–14 days is generally accepted. Consequently, various storage strategies can be applied to suit the market needs.

Sugars are one of the important components in the human diet, along with fats and proteins, which provide about 60-70% of their energy. Stevia is one of the most important medicinal plants with high antioxidant properties, obvious sugar characteristics, and without calories, which can replace sugars extracted from other sources. One of the features of this sweetener is that it is very useful for diabetics due to its lack of absorption in the digestive system. On the other hand, it is suitable for the diet of obese people due to its non-caloric nature. Sucrose is the transportable form of photosynthetic products, i.e. carbohydrates, in plants. Sucrose foliar spraying is important for the quick supply of compounds needed by plants.

This factorial experiment was carried out based on a randomized complete block design (RCBD) with four replications at Sari Agricultural Sciences and Natural Resources University from 2014 to 2015. Evaluated treatments consisted of different concentrations of a sucrose solution (0, 2.5, 5, and 10%). Thus, the mentioned material was diluted in solvents such as methanol 15%, boric acid (3 ppm), and acetic acid (1 ppm). Treatments were sprayed on plants at 10-day intervals until plants started the flowering stage. Some parameters, such as total chlorophyll, carotenoids, total phenol, total flavonoid, antioxidant activity, steviozide, and ribodiozide contents were measured at the beginning of flowering.

The results of the analysis of variance showed that the simple effect of the solvent type and sucrose concentration on all studied traits at the probability level of 0.01 and the interaction effect of the treatments on all traits, except for the amount of ribodiozide, were significant at the probability level of 0.05 and on the amount of steviozide at the probability level of 0.01. The average data comparison results showed that the amount of total chlorophyll in 10% sucrose concentration was significantly higher than the other sucrose concentrations. There was a significant difference between different concentrations of sucrose in terms of carotenoid content so that the highest (10.72 mg/g fresh weight) and the lowest (9.56 mg/g fresh weight) levels were recorded at concentrations of 5% and 0% sucrose, respectively. The amount of carotenoid in the methanol solvent (11.99 mg/g fresh weight) was significantly higher than in the other solvents, namely boric acid, acetic acid, and distilled water (its lowest amount). The amount of flavonoid was significantly different between different concentrations of sucrose and also in different solvents. Five percent sucrose concentration (10.82 mg of quercetin per gram of dry weight) and zero percent sucrose concentration produced the lowest (9.31 mg of quercetin per gram of dry weight) flavonoids. Based on the results of the data, the highest and lowest flavonoid contents were obtained in methanol (11.51 mg quercetin per gram of dry weight), boric acid (10.74 mg quercetin per gram of dry weight), acetic acid (9.42 mg quercetin per gram of dry weight) ), and distilled water (8.32 mg of quercetin per gram of dry weight) solutions, respectively. The amount of total phenol in the 5% sucrose concentration (19.54 mg of gallic acid per gram of dry weight) was significantly higher than in other concentrations. The results of comparing the average data showed a significant difference between different solvents in terms of the amount of total phenol so that the methanol solvent (23.07 mg of gallic acid per gram of dry weight) and the distilled water solvent (13.47 mg of gallic acid per gram of dry weight) contained the highest the lowest total phenol contents, respectively. The results obtained from this research showed a significant difference between different concentrations of sucrose in terms of the amount of antioxidants so that the highest (85.71%) and lowest (62.38%) amounts were found in five and zero percent concentrations, respectively. Based on variance analysis data, there was a significant difference in the amount of antioxidants in different solvents, and the highest and the lowest amounts were observed in methanol (90.59%) and distilled water (69.87%) solvents, respectively. Based on the obtained results, the methanol solvent had the highest (14.01%) and the distilled water solvent produced the lowest (11.27%) amounts of steviozide. Based on the comparison of average data, the lowest (5.77%) and the highest (13.01%) amounts of steviozide were measured at concentrations of 10% and 5% sucrose, respectively. According to the results of comparing the average concentrations of different sucrose levels on the amount of ribodiozide, the concentrations of 0% and 5% sucrose led to the lowest and the highest amounts of ribodiozide, respectively. According to the effect of the solvent, the highest and lowest amounts of ribodiozide belonged to methanol and distilled water solvents, respectively. Based on the mean comparison analysis, the most optimum amount of photosynthetic and phytochemical parameters were related to the concentration of 5% sucrose while the other concentrations were in the next orders. Moreover, the highest and the lowest optimum amounts were recorded in the methanol (15%), boric acid (3 ppm), acetic (1 ppm), and distilled water (control) solvents, respectively.

The studied carbon sources had a significant effect on many investigated traits. An increase in the concentration of assimilated carbohydrates as a result of sucrose application at a concentration of 5% with the methanol solvent may increase the availability of respiratory intermediates, which results in the reduction of non-photochemical energy loss. The occurrence of these biochemical phenomena caused by the consumption of intermediate substances ultimately increases the photosynthetic efficiency and improves the accumulation of photosynthetic substances, as well as the synthesis of secondary metabolites. Finally, it can be concluded that the application of sucrose with its appropriate solvent (methanol) could decrease or replace the absolute requirement for carbon source in the environment.

Nowadays, there is a growing demand for artificial preservatives-free food products, due to the concerns about their adverse effects. In recent years, numerous studies have led to the identification of various natural compounds have the potential to be used as preservatives in variety of food products. For instance, plant metabolites, such as the essential oils of aromatic plants, possess antioxidant and antimicrobial properties. These attributes have led to their widespread use in various industries, particularly in the food industry. Mayonnaise is one of the most popular and widely used sauces in the world, applied to prepare a variety of foods, such as salads and sandwiches. Due to the absence of thermal processing and the use of chemical artificial preservatives in mayonnaise, it is advisable to consume it in moderation and with caution. The aim of this study was to investigate the possibility of using Mentha spicata L. essential oil in the formulation of mayonnaise as a natural antioxidant and its effects on some physicochemical and microbiological properties of mayonnaise.

Fresh M. spicata leaves were collected from the northern of Iran and dried. The essential oil was extracted by distillation with water using a Clevenger device, and its volatile components were identified and measured by gas chromatography-mass spectrometry (GC/MS). The total phenolic content of the essential oil was determined by the Folin-Ciocalteu method. In addition, the free radical scavenging activity of the essential oil was evaluated by DPPH and ABTS assays, using BHT as a synthetic antioxidant as a reference. The minimum inhibitory concentration (MIC) of the essential oil was assessed against Gram-positive (Bacillus cereus, Staphylococcus aureus and Listeria innocua) and Gram-negative (Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa) bacteria. M. spicata essential oil was added to the mayonnaise sauce in different concentrations (500, 1000, 2000 ppm) and its antioxidant activity was investigated under accelerated oxidation conditions (90°C temperature) for seven days. In current research, the peroxide, acid, and thiobarbituric acid values of mayonnaise samples containing concentrations of 500, 1000 and 2000 ppm of M. spicata essential oil were calculated. Then, they were compared with sauce samples containing concentrations of 100 and 200 ppm of BHT artificial preservative.

32 compounds were identified in the essential oil by GC-MS and the results showed that carvone (57.01%), d-limonene (16.79%), 1,8-cineole (7.56%) and beta-caryophyllene ( 2, 10%) were the main components of M. spicata essential oil. The total phenolic contents of the essential oil were found to be 0.246 mg of gallic acid per gram (dry weight). The tests performed for peroxide, acidity and thiobarbituric acid values showed that the use of high concentrations of the essential oil can be a favorable alternative to artificial antioxidants in mayonnaise. Additionally, the results of the antibacterial activity demonstrated that the diameter of the microbial growth inhibition zone of pathogenic Gram-positive Bacillus cereus and Staphylococcus aureus strains was greater than the Gram-negative strains of Pseudomonas aeruginosa, Escherichia coli and Salmonella typhi. However, among the pathogenic Gram-positive strains, Listeria innocua strain had the smallest microbial growth inhibition zone. Furthermore, the results of sensory evaluation showed that the essential oils concentrations of up to 1000 ppm had no significant effect on the sensory characteristics of mayonnaise.

Based on the findings of this study, it is possible to propose the use of M. spicata essential oil, known for its mild and pleasant aroma, as a natural antioxidant to prevent oil oxidation and extend the shelf life of mayonnaise.

Plant sprouts are receiving a great deal of attention because of their ‎abundance, bioavailability of components, and health benefits. Germinated legume seeds were the most ‎common sprouts consumed in the human diet. Alfalfa (Medicago sativa) sprout is a valuable source of ‎protein, fiber, minerals, vitamins (B vitamins), glucosinolate, and phenolic compounds. Alfalfa sprout is ‎usually consumed as dehydrated leaves, powder, or dietary supplements in the form of tablets. ‎Regarding nutritional values, alfalfa sprout powder (ASP) could act as a prebiotic agent. The present ‎study aimed to investigate the nutritional values and in vitro prebiotic potential of ASP on two probiotic ‎strains, namely Lactobacillus casei ATCC 393‎‏ ‏and Bifidobacterium longum ATCC 55813. Also, the ‎effects of fermentation of ASP by probiotics on polyphenolic content and antioxidant activity were ‎investigated. ‎

Fatty acid composition, amino acid profile, and mineral content of ASP were ‎determined using a gas chromatography-mass detector, amino acid analyzer, and inductively coupled ‎plasma-optical emission spectrometry, respectively. ASP at two concentration levels of 0.5 and 1% was ‎tested for its growth stimulation effect on two probiotics, L. casei and B. longum. Fructooligosaccharide ‎‎(FOS) and glucose were used as standard prebiotic and control positive, respectively. The changes in ‎probiotic populations and pH were monitored during 48 h fermentation in glucose-free MRS broth (GF-‎MRSB). The total phenolic content (TPC) and antioxidant activity of ASP were evaluated during ‎fermentation using the Folin–Ciocalteu method and the DPPH radical scavenging assay. ‎

ASP contains high levels of aspartic acid, glutamic acid, and essential amino acids, including ‎phenylalanine, leucine, and lysine. It also includes a high content of unsaturated fatty acids, including ‎linoleic and oleic acids. Potassium was found to be the mineral with the highest composition, followed ‎by phosphorus and calcium. Both probiotic strains could grow effectively in the presence of ASP. The ‎cell numbers of L. casei and B. longum increased by 4.91 and 5.11 Log CFU/ml after 48 h fermentation ‎of ASP-1%, which were comparable with the stimulatory effects of FOS and glucose. The pH decrease ‎of GF-MRSB was negatively‏ ‏correlated with the concentration of ASP. Antioxidant activity and TPC ‎increased continually during fermentation by both probiotics, with L. casei exhibiting a stronger impact. ‎

Results demonstrated that ASP is an excellent source of minerals, essential amino acids, ‎and unsaturated fatty acids. Probiotic bacteria not only survive in the presence of ASP but also increase ‎polyphenolic content, thus enhancing the antioxidant activity and functional capacity of the fermented ‎ASP. Fermenting phenolic compound-rich plant sprouts with probiotic bacteria can be considered a ‎novel approach to the development of functional foods.‎