f.shahidi

Oxidation reactions and microorganisms’ activity are considered as the most important factors affecting the quality of food products. Recently, in the light of the inefficiency of some chemical preservatives against microorganisms and the presence of toxic residues in food products, the use of natural antimicrobials and antioxidants has been increased. Natural antimicrobial compounds have the potential to control microbial contamination and reduce the use of antibiotics. Plant essential oils are natural compounds with the potential to be used as active ingredients in the food, pharmaceutical, and cosmetic industries. Various studies have shown that essential oils have antifungal, antibacterial, antiviral, and antioxidant activity. The essential oils are considered as superb preservatives with various biological functions. Essential oils are generally recognized as safe product (GRAS) which can be used as an alternative to synthetic additives.Grapefruit (Citrus paradisi) peel and fruit contain active ingredients such as acids, flavonoids, vitamin C, and potassium, and its essential oil is composed of terpenic hydrocarbons, such as citral, limonene, citronelal, and geraniol. Although plant essential oils have antimicrobial and antioxidant properties, one of the main problems of these natural compounds is their high volatility and instability. In this context, nanoemulsion formulations are frequently used to increase the stability and efficiency of these biologically active compounds. This study is therefore aimed to nanoemulsifying the grapefruit essential oil and evaluate its antioxidant and antimicrobial properties.

β-carotene, linoleic acid, ABTS (2,2’-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), and DPPH (2,2-diphenly-1-picrylhydrazyl) were purchased from Sigma-Aldrich Co. (USA). Mueller Hinton Broth (MHB) and Mueller Hinton Agar (MHA) were supplied from Merck Co. (Darmstadt, Germany). Grapefruit peel was dried at ambient temperature and then powdered. The obtained powder was then transferred to a Clevenger device containing 750 ml of distilled water to perform the distillation extraction (3 h). The resulting grapefruit essential oil was stored at 4 °C until use. Grapefruit essential oil was prepared using the hydrodistillation method, and then nanoemulsified. The antioxidant activity of the nanoemulsified essential oil was investigated by DPPH and ABTS  radical scavenging activity and beta-carotene/linoleic bleaching test. The nanoemulsified essential oil or methanolic (control) was mixed with DPPH solution and the mixture was then stored at ambient temperature for 30 min, in a dark place. The control sample was prepared by methanol. The absorbance of the samples was measured at 517 nm. To determine the ABTS-RS activity, the nanoemulsified essential oil was briefly charged with methanolic ABTS radical cation solution and the resulting mixture was left at room temperature for 30 min. Afterward, the absorbance was read at 734 nm. A spectrophotometric method was applied to monitor β-carotene/linoleate solution bleaching in the presence of the nanoemulsified essential oil. To do this, the absorbance of the solution was recorded at 490 nm after 120 min against the control sample at time zero and after 120 min. Antibacterial effect of the grapefruit essential oil nanoemulsion was also evaluated against Escherichia coli ATCC 25922, Salmonella typhi ATCC 6539, Pseudomonas aeruginosa ATCC 27853, Listeria innocua ATCC 33090, Staphylococcus aureus ATCC 25923, Bacillus cereus ATCC 14579, Bacillus subtilis ATCC 23857, Streptococcus pyogenes ATCC 19615, and Staphylococcus epidermidis ATCC 12228, based on disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration.

The results showed that the nanoemulsion of grapefruit essential oil had a remarkable antioxidant effect of 42.27 mg/ml, 33.27 mg/ml and 54.54%, respectively, based on DPPH, ABTS, and beta-carotene-linoleic acid bleaching tests. According to disk diffusion agar and well diffusion agar results, the lowest inhibition zone was related to E. coli and the highest inhibition zone was observed in L. innocua. The minimum inhibitory concentration for L. innocua and S. aureus (the most sensitive bacteria) was 25 mg/ml, and E. coli, S. typhi, and P. aeruginosa had the highest inhibitory concentration. Also, the lowest bactericidal concentration was related to L. innocua and S. aureus bacteria and the highest concentration was observed for E. coli, S. typhi and P. aeruginosa. The nanoemulsified essential oil generally exhibited greater antibacterial activity against Gram-positive species. This could be mainly due to the difference in the cell wall composition of Gram-positive bacteria in comparison to Gram-negative; Gram-positive bacteria have a thicker mucopeptide layer in their cell wall, while Gram-negative bacteria have only a thin layer of mucopeptide and the wall structure is mainly composed of lipoprotein and lipopolysaccharide, thereby leading to a higher resistant to antibacterial agents According to the results, grapefruit essential oil nanoemulsion can be used as a natural antioxidant and antimicrobial agent to control oxidation reactions and the growth of spoilage and pathogenic microorganisms.

Serum levels of cardiac troponin (CTnI) and creatine kinase (CK-MB) are two indicators of cardiac cell damage. The present study aimedto investigate the effect of different volumes of a high-intensity interval training (HIIT) course on serum CTnI and CK-MB levels in cardiac patients after myocardial infarction (MI).

In this semi-experimental study with pretest–posttest design, thirty patients (50.03±4.32 years) with documented MI were selected voluntarily. Regarding the researchcriteria, all participants were randomly assigned into three groups (n=10 per group): Acontrol group and two high-volume HIIT training (HV-HIIT) and low-volume HIIT training (LV-HIIT)groups.The HV-HIIT group did exercisesthree days a week for 40 minutes, and the LV-HIIT group didexercises three days a week for 20 minutes.Blood samples were taken before and after the 12-week intervention. Statistical analysis of the variables was performedusingpaired t-tests, one-way analysis of variance, and Tukey's post hoc test.

At the end of the intervention, CTnI in the LV-HIIT and HV-HIIT groups decreased significantly (70% and 50%, respectively); however, no significant change was observed in the control group. CK-MB levels showed a significant decrease (26%)only in the LV-HIIT group. In the serum levels of CTnI, a significant difference was observed amongthe three groups (p=0.035), and the results of Tukey's post hoc test showed a significant difference between the control and LV-HIIT groupsin terms ofdecreasedCTnI levels(p=0.012).

LV-HIIT training as an exercise strategy for cardiac rehabilitation programs after MI can improve cardiac injury indices more effectively than HV-HIIT and is associated with less cardiac damage and fatigue.

Use of wastes such as seeds of summer crops leads to re-enter these valuable sources into the food cycle. Therefore, it causes enhancement of the nutritional values and production of functional foods in food industries. The aim of this study was assessment of the effects of feed composition variables and screw speed on physicochemical and sensory characteristics of breakfast cereals based on cornmeal and wheat flour enriched with melon seeds to achieve optimal results.

In this study, response surface methodology was used to estimate effects of formulation variables, including melon seed flour (10–20%), moisture content (12–20%) and screw speed (120–180 rpm) on expansion ratio, bulk density, hardness, water absorption index, water solubility index and sensory acceptance.

Results showed that increases in melon seed in mixtures of cornmeal and wheat flour increased density and hardness of the extruded snacks while the expansion ratio and water absorption decreased. The optimum conditions for the production of snacks included 10.1% melon seeds, 18% moisture content and 172.39 RPM screw speed.

In Conclusion, breakfast cereals with whole melon seed flour can be suggested as functional foods with nutritional and health benefits. The final product includes desired sensory characteristics and consumer acceptability.

Exercise has an effective role in physical and mental health by reducing the health risk factors.
The study aimed to compare the effect of eight weeks of aerobic and resistance training with quercetin supplementation on VEGF of cardiac tissue in rats. 35 Rats with an age average of 8-10 weeks were randomly divided into 7 groups (aerobic, resistance, aerobic + supplement, resistance + supplement, supplement, sham, and control). After two weeks of familiarity with the environment and learning the exercise, The Exercise groups practiced according to the protocol for 8 weeks. The groups that should have received supplements received quercetin supplement at the rate of 50 mg/kg three days a week for 8 weeks as a peritoneal injection. 48 hours after the last training intervention, rats were anesthetized and killed using CO2. The, samples were taken from the heart of rats. ELISA method was used to measure VEGF concentration. One-way ANOVA and Tukey Post Hoc test in P≤0.05 level by SPSS 22 was employed.
The results showed that eight weeks of aerobic and resistance training and aerobic with quercetin significantly increased the VEGF concentration of rat heart compared to the control group (P≤0.05), while, there was no significant difference in the level of VEGF in heart tissue compared to the control group and supplement (P=0.148).
In general, quercetin consumption inhibited angiogenesis, while, it did not happen in the supplement + aerobic group (P=0.011), that means that aerobic has overcome the inhibitory effects of quercetin on angiogenesis.

The highconsumption of low nutritional value snacksand malnutrition of children and teenagers are one of the major problems in society. Usually, the small seeds that are in watermelon, although they are rich in nutrients including fatty acids, essential proteins, and many minerals are not used and have been thrown away.

This study was performed on the basis of a rotating central composite design. The effects of extrusion variables including screw speed (120-180 rpm), watermelon powder (10-20%) and feed moisture content (12-20%) on the physicochemical properties (expansion ratio, oil and water absorption index, porosity, and total acceptance) of expanded snack on the basis of corn-wheat flour grits were evaluated.

The results showedthat watermelon flour decreased the expansion coefficient and porosity, however, the interaction effect of screw speed and watermelon flour improved the physicochemical properties of the samples. The increasing screw speed led to a decrease in the viscosity and therefore the expansion coefficient and porosity increased.

The optimization of snack formulation was performed to find the optimum conditions of production. The watermelon flour of 11.31%, feed moisture content of 15.56% and a screw speed of 171.15 rpm were found to be to optimum conditions.

The aim of this study was comparing professional futsal practice sessions with and without blood flow restriction on angiogenesis and angiostatin stimulation in active young men. Among physical education students, 12 volunteer selected and randomly divided into two groups of exercise with and without blood restriction. All of the subjects did the 3 vs. 3 professional futsal practice in 6 repetition of two minutes. One minute determined as resting time between the repetitions. In exercise group with blood restriction, a cuff on the thighs with pressure of 140 Mm Hg were applied. The blood samples were collected before and after the exercise sessions to determine the ratio and values of VEGF and endostatin concentration. Elisa method was used to measure the variables. To determine within and between group differences, Paired T test and Independent T test were used respectively at significance level of 0.05. The results showed no significant differences for the measured variables between the groups. However, VEGF significantly decreased in the two groups after exercise session (P=0.002). The ratio of VEGF to endostatin significantly increased in exercise with blood flow restriction group (P=0.002), but not in the Exercise group (P=0.006). Interestingly, the endostatin concentration increased significantly after the trial (BFR: P=0.003, NONBFR: P=0.005). Blood lactate was significantly higher in exercise group with blood restriction(P=0.003). In conclusion, a professional futsal practice session can decrease blood level of VEGF and increase its endostatin.

In this study, the effect of “Osmodehydrofrozen” fruit addition on sensory, physical, chemical and microbiological properties of concentrated yoghurt and its quality during storage was evaluated. This research was done in two stages. At the first stage, fruit percentage, type and addition time (before and after fermentation) was determined. The results indicated yoghurts containing 10% apple or 13% strawberry, which was added before fermentation had a better quality. Because of high osmotic activity of apple, the synersis was lower in apple yoghurt in comparison with strawberry yoghurt. According to osmotic activity of both fruits, the synersis value was much lower than that of fruit yoghurts, which contained untreated fruits. Taste value was higher in strawberry yoghurt and texture and mouth feel values were higher at low percentages of fruit. The results of the second stage (quality evaluation during storage) indicated that storage had a significant effect on pH, acidity, synersis, taste and texture (P<0.05). In samples which contained apple, coli forms disappeared after 7 days of storage. In samples that contained strawberry, coli forms disappeared after 7 days of storage.

This study was intended to use the sourdough LAB containing specific starter cultures for Barbari bread production and reduction of its staling. For sourdough preparation, fresh microbial cells were collected by centrifugation from LAB cultures. Then 1.5% of flour (w/w) from these washed cells with the same amounts of wheat flour and tap water and 0.25% (w/w) active dry yeast extract, containing Saccharomyces cerevisiae were mixed. The effects of fermentation time (8, 16 and 24 hours), fermentation temperature (28, 32 and 36 ºC) and type of starter culture (Lactobacillus sanfransicencis, Lactobacillus plantarum and a mixture of both LAB) were analyzed in a completely randomized design with factorial experiment with 4 replications. Bread staling was determined by its measuring crumb hardness and specific volume in 1, 24, 48 and 72 hours after baking. Correlation between variables was obtained by multivariate regression, and regression models were exhibited. The results showed that sourdough had significant effect (p≤0.05) on reduction of Barbari bread staling at 1, 24, 48 and 72 hours after baking in comparison with control sample. Moreover, the sample prepared with Lactobacillus plantarum (24 h fermentation time and 32 ºC fermentation temperature) had the maximum specific volume and the least staling, 72 hours after baking.

Saffron is one of the most important crops in Iran and the quality of its dried stigma is highly depended on the processing and storage conditions. In this study, the effect of different storage conditions in terms of temperature (20, 30 and 40°C) and water activity (0.32, 0.52 and 0.75) during 12 weeks storage on color strength, aroma and bitterness of saffron were investigated. In order to study of moisture (water activity) different saturated solution of MgCl2, Mg(NO3)2, MgBr2 and NaCl in the various temperatures were used. Results showed the color strength decreased as temperature increased. Increasing of water activity resulted in deterioration of crocin and consequently decreasing of color. Furthermore, after 12 weeks of storage, the color strength had a noticeable decrease, the bitterness also decreased but the aroma increased.

Cantaloupe (Cucumis melo L.) is one of the most important melons in Iran especially in Khorasan province. The cantaloupe seed is a good functional and nutritional source for human, having large amounts of essential amino acids and unsaturated fatty acids. In spite of nutritional and functional aspects, it does not have considerable applications in food industry yet. Cantaloupe seed milk's pH is about 6.8, so cannot be stored for a long time. In this work, pH of cantaloupe seed milk decreases to 4.15 in 3 treatments (citric acid, orange concentrate, and orange sacs) and a constant amount of lemon juice. At first, nutritive value of seed milk was measured. According to results, this milk is a good source of protein (1.52%), phosphorus (41/3 ppm) and potassium (17 ppm). After that, storage stability of cantaloupe seed beverage at refrigerator temperature (4 °C) for 42 days was evaluated by analyzing changes in the chemical, microbial and sensory properties. The results showed that the orange concentrate-cantaloupe seed beverage reached the highest score of total acceptance (3.67 on a 5-point hedonic scale). In these conditions, we couldn’t find any molds and yeasts in the samples, thus the shelf life of the mentioned beverage could be 6 weeks at 4 °C.

The aim of this study was to use Alpha-amylase termamyl 2-x for maltodextrin production from corn starch and evaluate its industrial uses. Based on the results obtained in laboratory, this process was accomplished in pilot plant scale. The process included preparation of starch suspension, pH adjustment, addition of enzyme, heating under stirring, continuous control of DE and Brix, enzyme inactivation in adequate DE, separation of soluble sections by centrifuge and finally spray-drying of the maltodextrin liquid. In this investigation, the amount of DE at dry matter was calculated under three enzyme concentrations (0.2, 0.25 and 0.3 ml of Alpha-amylase termamyl 2-x per Kg of starch) and in three different hydrolysis temperatures (60, 65 and 70 ºC) at constant pH (6). A completely randomized design with factorial arrangement and 5 replications was conducted. To study the relationship between DE and different parameters, multiple linear regression was used. Finally, for approximation of DE (based on enzyme concentrations, temperatures and hydrolysis times) a regression model was used. The results from different enzyme dosages at the same temperature and time of hydrolysis differed significantly (p≤ 0.05). Meanwhile, the best enzyme concentration and hydrolysis temperature for maltodextrin (high DE) production after 300 minutes were 0.25 ml of enzyme per kg of starch and 70 ºC, respectively. In these conditions, the least residual starch concentration and residual Alpha-amylase activity were observed.

Bulk tomato paste is produced in concentrations higher than 35% (350 Brix scale) and its packaging is not hermetic. In recent years, the production of this product in our country has considerably increased. One of the most important problems in the tomato paste industry of Iran is the preservation of bulk tomato paste. Shelf-life of tomato paste depends on many factors such as initial quality of tomato paste, cooling conditions, salting, packaging, handling, and cold storage. The product factors evaluated in this study included: 1) microbial parameters such as total count, acid-resistant microorganisms, and Howard Mould Count and 2) physico-chemical parameters such as acidity, pH, amount of lactic acid (D and L forms), and total dry matter. Experimental data showed that using high brix (35-38) in producing tomato paste along with salting the product surface and storing it at 0 ºC had only a limiting effect on microbial changes and could not prevent their growth completely. However, salting treatment had a great effect on surface growth of fungi and their ability to produce colonies and mycelia. On the basis of the results obtained from this study, cooling of bulk tomato paste in ambient temperature is critical to bulk tomato paste production process and also has an important effect on the quality and shelf-life of the product.

The antifungal effect of sodium diacetate on inhibiting the growth of some bread spoiling molds was examined both in culture media and in flat bread “In situ”. In the first step, the antifungal effect of different concentrations of sodium diacetate: 0, 1000, 2000, 3000, 4000, and 5000 ppm were examined against Aspergillus sp., Aspergillus niger, Rhizopus sp., and Penicillium sp. The results indicated that as the concentration of sodium diacetate increased, the mold growth decreased. At 5000 ppm the mold growth was inhibited up to fifth day (the last day of experiment). Based on these results, the antifungal effect of different concentrations of sodium diacetate was evaluated in bread “In situ”. In this stage Aspergillus sp. was selected as the indicator mold. The results indicated that if 3000 ppm of sodium diacetate is used, not only mold growth is inhibited but bread staling can also be prevented. This concentration of sodium diacetate does not have any harmful effect on texture and flavour, and can increase bread shelf life up to four days. Higher concentrations of sodium diacetate can inhibit mold growth completely, but have negative effects on texture and flavour. Therefore, 3000 ppm of sodium diacetate is recommended for increasing bread shelf life.