فصلنامه علوم تغذیه و صنایع غذایی ایران
سال هجدهم شماره 2 (پیاپی 71، تابستان 1402)

Oxidative stress is one of the effective mechanisms in neurodegeneration and aging process in central nerve system. The aim of this study was to investigate effects of aerobic exercises with tryptophan supplementation on enzymatic antioxidant defense and lipid peroxidation in brain tissues of elderly rats fed with high-fat diets.

In this experimental study, 36 elderly male Wistar rats (age of 18 months and mean weight of 500 g ±100) were randomly divided into five groups including normal food control, G1 (n = 6); high-fat food, G2 (n = 6); high-fat food and exercise, G3 (n = 8), high-fat food and supplement, G4 (n = 8); and high-fat food, exercise and supplement, G5 (n = 8). Aerobic interval training program was carried out on treadmill including three days per week at speeds of 12–26 m/min for eight weeks. Each rat in the supplemented groups (G4 and G5) was administrated with 100 mg of tryptophan supplement per kilogram of body weight daily via gavage. Serum levels of superoxide dismutase, malondialdehyde and lactate dehydrogenase were assessed using kits and enzyme-linked immunosorbent assay. Data were analyzed using independent t-test and MANOVA test at p < 0.05.

Results showed no significant differences between the two groups of normal and high-fat foods for the highlighted factors as well as interactive effects of exercise and supplementation for weight factor (p = 0.441), brain tissue weight (p = 0.78), ratio of brain tissue weight to total weight (p = 0.47), malondialdehyde (p = 0.13), superoxide dismutase (p = 0.55) with no significant differences. However, significant differences were observed for LDH (p = 0.05).

It seems that high-intensity interval training with tryptophan supplementation does not include effects on antioxidant system and lipid peroxidation in brain tissues of elderly rats.

A few studies have assessed associations between the number of eating occasions (EOs) and energy intake from meals and snacks with metabolic syndrome. The aim of this study was to investigate EOs and energy intake from meals and snacks and their relationships with metabolic syndrome in 20–60 year-old employees of Bandar Mahshahr Petrochemical Company, Bandar Mahshahr, Iran.

In this cross-sectional study, 293 petrochemical workers were selected using census method. Food record were collected for three days [fixed workers:two days of working days (Days 1 and 2) and one day of rest (Day 3); and shift workers:one day of working (Day 1), one night shift working (Day 2) and one rest day (day 3). Demographic and socioeconomic information and chronotype were collected using valid questionnaires. In this study, eating occasion was defined as energy intake of 50 kcal or more per hour of the day. Differences and associations between the number of EOs  and the portion of energy from the main meals and snacks with metabolic syndrome were investigated using Mann-Whitney test and logistic regression analysis, respectively.

The mean and standard deviation of the number of eating occasions of shift workers were significantly higher than fixed workers (p < 0.01) and the meals frequency of fixed workers were significantly higher than shift workers (p < 0.01). The mean and standard deviation of total energy intake at Day 2 (night working) of shift workers were significantly higher than fixed workers (p < 0.01) and energy intake of meals at Day 3 of fixed workers were significantly higher than shift workers and energy intake from snacks at Days 2 and 3 and average of 3 days of shift workers were significantly higher than fixed workers (p < 0.01). After adjusting for the effects of confounders, shift workers with a higher proportion of energy intake from meals (main meals and snacks) were more likely to suffer from metabolic syndrome and its complications. Furthermore, one unit increase in the number of EOs, meals and snacks was associated with increasing the chance of hypertriglyceridemia and high waist circumference. In fixed workers, possibility of metabolic syndrome and high waist circumference was increased with the increases in the number of EOs  and snack and energy intake of meals and snacks. Moreover, the likelihood of hyperglycemia was rised with an increase in the portion of energy intake from snacks. Chances of hypertriglyceridemia and high LDL-C was increased with increasing in the number of snacks and energy intake of snacks (p < 0.05). 

This study revealed the importance of paying attention to nutrition in shift workers through training and nutritional interventions and diagnosing the risk factors linked to working conditions in decreasing risks of metabolic syndrome and its complications.

Dairy consumption is affected by several factors, including physical and economic accesses and individual preferences. Considering that social networks can reflect views of their users, this study was carried out to explain perspectives of Iranian Instagram social media users regarding dairy product consumption.

Data were collected using directed qualitative content analysis approach. Studied areas included hashtags that were collected based on the objectives of the study with the purposeful sampling method on Instagram, January 2011 to March 2021. The MAXQDA software was used for content coding and analysis. Validity of data was assessed using criteria of validity, transferability, trust and confirmation.

A total of 782 posts with desired characteristics were collected. The most important themes identified in the posts of Iranian Instagram users included positive effects of dairy products in preventing diseases, necessity of consuming dairy products, safety and quality of dairy products, frauds in dairy products, disadvantages of consuming dairy products in causing diseases and harming the environment and animals and obstacles to dairy consumption such as high prices and poverty of the people. Some users tried to guide others to consume dairy products and introduced new products of dairy industries such as enriched dairy products and probiotics.

Considering broadly increasing use of social networks, production of scientifically sound contents by experts can be the major suggestion of the present study to improve awareness of the users of these networks. Due to the importance of dairy consumption, it is recommended to set educational programs according to the needs of different age groups in the country's media. Results of the present study can be used by the policymakers in adopting right policies on dairy consumption.

Medicinal plants are some of the most important sources of medicine in several countries. Urinary tract infection is one of the most common infections and blood infection is an important cause of death worldwide. Antibiotic resistance has increased as a fundamentally global problem that needs appropriate alternatives. Fumaria parviflora Lam, Myrtus communis L., Matricaria recutita L. and Nigella sativa L. are some of the most important plants in traditional medicine.

First, plants were powdered using electric grinder and then the hydroalcoholic extract was prepared using maceration method. After dispersing alcohol, this was lyophilized and three concentrations of 64, 160, and 220 mg/ml were prepared. Antimicrobial effects were assessed using disk diffusion method and antioxidants were investigated using DPPH method.

The highest percentage of inhibition for the Myrtus was against Escherichia coli bacteria (86%) and Pseudomonas aeruginosa (100%) compared to gentamicin and 100% resistance was observed for Staphylococcus aureus compared to erythromycin. Nigella sativa included the highest antioxidant effect (nearly 60%) and Myrtus with 43% had the lowest antioxidant effect. Using Gas chromatography-mass spectrometry, it was detected that the most effective substances in Myrtus, Nigella sativa, Fumaria parviflora and Matricaria respectively were benzotriol (30.97%), octadecadienoic acid (44.35%), pyran (13.26%) and benzopyran (50.24%).

Myrtus plant includes the most antimicrobial effects and Nigella sativa includes the most antioxidant effects.

Celiac disease is an autoimmune illness that occurs due to the body intolerance to gluten protein in humans. Research have shown that probiotics can promote health in people with celiac disease through regulating inflammatory processes and hydrolyzing peptides in the small intestine. The present study was carried out to investigate ability of a mixture of native Iranian probiotics (one strain of Lactobacillus spp. and three strains of bifidobacteria) with their paraprobiotic cells in hydrolysis of gluten peptides.

Gliadin protein mixture and its peptides before and after treatment with probiotics in presence and absence of paraprobiotics were analyzed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and enzyme-linked immunosorbent assay.

Results of the experiments showed that human digestive enzymes could not hydrolyze gliadin peptides and gastric hydrolyzed gliadin was well decomposed by the probiotics in presence of paraprobiotics. Moreover, low-molecular weight components achieved with no toxic effects in celiac patients.

Results of the current study revealed that the mixture of native Iranian probiotics in presence of their paraprobiotics might play protective roles in celiac patients.

Allium jesdianum and its extract include antioxidant effects. The aim of this study was to optimize extraction conditions of Allium jesdianum to assess antioxidant characteristics of the extracts and its phenolic compounds as well as assessing in vitro protoscolicical effects of the extracts.

Extracts of Allium jesdianum were prepared using various ethanol concentrations of 0, 50 and 100% at various extraction times of 24, 48 and 72 h. The optimal extract conditions were estimated using response surface methodology and the optimized extract was chosen for the experiments. Then, concentrations of 200, 400 and 600 ppm were prepared to assess their protoscolicical effects after the parasite exposure for 5, 15 and 30 min.

Increases in the extraction time were positively correlated with increases in phenolic compound concentrations and antioxidant characteristics of the extracts. However, increasing ethanol concentrations included inverse effects on the two parameters. Moreover, 100 µl/ml aqueous extract of Allium jesdianum (63.90 min) inactivated 100% of protoscoleces after 30 min of exposure.

Results showed that aqueous extracts of Allium jesdianum could inactive protoscoleces of hydatid cysts in vitro.

Potato fried, despite their large proportions of oil and adverse effects on health, are one of the most popular products in the food industry. Therefore, decreasing oil absorption during frying can be an important goal of French fries processing. In this study, effects of microwave pretreatment on oil absorption and qualitative characteristics of potato fries during deep frying were investigated.

Potatoes were stored in refrigerators at temperatures higher than zero (4 ℃ ) for 24 h before beginning the experiments. Microwave pretreatment was used with powers of 200, 300, 400 and 500 W and times of 2, 4 and 6 min and the frying process was carried out at temperatures of 160 and 180 ℃ . Furthermore, moisture content, oil absorption, color component, texture hardness and, shrinkage of the samples were assessed as well as sensory evaluation of the samples.

Microwave pretreatment included significant effects on moisture content, absorbed oil, color indices and texture hardness of the samples (p < 0/05) with no effects on shrinkage (p > 0/05). Of various treatments, the greatest effect was observed with the power of 500 W for 6 min at 160 and 180 ℃  (8.105 and 11%).

Results showed that at higher powers and times, the intensity of decreases in oil absorption increased. It can be concluded that use of microwave is an appropriate, easy available pretreatment to decrease oil content and improve quality characteristics of potato fries.

Contaminated foods with Shiga toxigenic serotypes of Escherichia coli (STEC) can cause diarrhea and severe diseases in consumers. The aim of this study was to investigate frequency of Shiga toxigenic Escherichia coli serotypes and their antibiotic resistance patterns in vegetable samples from Tehran, Iran.

In this study, a total of 97 vegetable samples from 22 urban areas of Tehran, Iran, were investigated, July 2018 to March 2019. To identify Shiga toxigenic Escherichia coli strains, standard method of enrichment and culture in selective media and polymerase chain reaction for verifying presence of stx1 and stx2 genes were used. Presence of eae and ehxA genes was investigated in Shiga toxigenic Escherichia coli isolates. Antibiotic resistance was assessed using disk diffusion method for 15 antibiotics and the multidrug resistance phenotype was assessed.

Shiga toxigenic Escherichia coli strains were isolated in 14/4% of vegetable samples (stx1, stx2, stx1/stx2 of 8, 1 and 5%, respectively). Presence of eae and ehxA genes was shown in 1 and 2% of Shiga toxigenic Escherichia coli isolates, respectively. The highest resistance was detected to trimethoprim-sulfamethoxazole (100%), erythromycin (73.33%) and tetracycline (85.7%) and the lowest against meropenem (0%) and imipenem/ceftazidime (7/7%).

In this study, contamination of vegetables with multidrug resistant Shiga toxigenic Escherichia coli was verified in Tehran, Iran. Further studies on human samples can clarify this contamination.

Plant essential oils are volatile aromatic oil compounds that have been addressed as natural preservatives due to their strong antibacterial and antioxidant characteristics. In this study, effects of using Heracleum persicum essential oil nanoemulsion on the shelf life of shrimp nuggets were investigated.

Chemical compounds of Heracleum persicum essential oil were assessed using gas chromatography. Effects of H.persicum essential oil nanoemulsion containing concentrations of 0, 0.5, 1 and 2 % on the shrimp nugget shelf life stored for 15 days were assessed at refrigerator temperature. The parameters assessed included thiobarbituric acid index, peroxide value, free fatty acids, total volatile basic nitrogen, total viable count and sample color indicators.

The major compounds of the H.persicum essential oil include 43.29% butanoic acid, cyclopropane 14.14%, methylbutane 5.50% and hexanoic acid 5.27%. After coating the shrimp nuggets with H.persicum essential oil nanoemulsion, pH of various treatments included no significant differences (p> 0.05). During 15 days of cold storage, thiobarbituric acid index, peroxide value, free fatty acids, total volatile basic nitrogen and total viable count increased. The lowest levels of these indices were observed at the end of the storage time in samples with 2% concentration of H.persicum essential oil nanoemulsion (p< 0.05). The color index of b* decreased by increasing the essential oil percentage, but the indices of L* and a* were not significant (p> 0.05). The 2% H.persicum essential oil nanoemulsion treatment showed the highest efficiency of increases in shrimp nuggets (p < 0.05).

Shrimp nuggets in 2% essential oil nanoemulsion treatment included the permissible limit of consumption until Day 9 and this treatment was able to increase shelf life of the nuggets for three further days, compared to the control and other treatments.

The objective of this study was to investigate effects of Sargassum ilicifolium, Ulva lactuca and Gracilaria cortica algae on physicochemical, microbial and sensory characteristics of processed fruits (plums).

The novel formulation was prepared by adding various concentrations (1.5 and 3%) of algae to the processed fruit (plums). Physicochemical (moisture, ash, pH, acidity, SO2, amino acid composition and texture), microbial (total count and coliforms, Escherichia coli, Staphylococcus aureus, acid-resistant bacteria, mold and yeast counts) and sensory (color, taste, texture and overall acceptance) characteristics of consolidated samples were assessed using SPSS statistical software.

Results showed that the moisture content, ash, insoluble ash, pH, acidity, salt and sulfur anhydride in various samples were in the range of national standards of Iran. The moisture content decreased while pH increased during the storage. Seventeen amino acids including essential and non-essential amino acids such as aspartic acid, glutamic acid, serine, histidine, glycine, threonine, arginine, alanine, proline, tyrosine, valine, methionine, cysteine, isoleucine, leucine and phenylalanine were identified. Microbial contamination of the samples decreased during storage. Escherichia coli and Staphylococcus aureus counts were not reported in the samples. Coliforms, acid-resistant bacteria, mold, and yeast populations of various samples did not include significant differences (p ˃ 0.05).

Addition of algae does not include negative effects on sensory, physicochemical and microbial characteristics of the processed fruits. Sometimes, it improves the highlighted characteristics and the final product is in accordance with the national standards of Iran.