Journal of Nutrition, Fasting and Health
Year:2020 | Volume:8 | Issue:4|Papers Count:11

Ultrasonic waves cause an increase in oil extraction efficiency through their mechanical effects, cavitation, and the energy generated by this phenomenon. Temperature, time, solvent to sample ratio, solvent type, and ultrasonic power are the most effective factors in the ultrasound-assisted extraction of oils. Temperature increase reduces the surface tension and vapor pressure of the solvent, leading to a rise in the solvent diffusion into the cell, and thus, the extraction efficiency increases. However, as the temperature approaches the solvent boiling point, its vapor pressure rises. Due to the smaller pressure difference between the interior and exterior of the cavitation bubbles, they collapse less intensively and cause the extraction efficiency to decrease. The increase in ultrasonic power has a similar effect on extraction efficiency. An elevation of the extraction time improves this parameter in the early minutes of extraction, by destroying the cell walls and making the oil diffuse out of the cell-matrix. An increase in the solvent to sample ratio up to an optimal level elevates the concentration gradient of the solvent towards the sample matrix by reducing the solution viscosity and brings about an improvement in the extraction efficiency. The application of the solvents with high vapor pressures results in a decrease in the cavitation energy because of the pressure difference between the cell interior and exterior. Therefore, such solvents do not have a positive effect on the extraction efficiency. Each of the aforementioned factors has its optimum level to enhance the ultrasound-assisted extraction efficiency.

Introduction: Antimicrobial agents such as essential oils have wide applications, and their use in edible films has been reported to enhance the shelf life of meat and its products. The present study aimed to assess the effects of chitosan films on the inhibition of Staphylococcus aureus in hamburger samples in storage conditions (temperature: 4± 1° C). Methods: The prepared films contained 0. 8% nanoemulsion of Bunium persicum essential oil (NBPEO) and 1. 6% nanoemulsion of Trachyspermum ammi essential oil (NTEO). The hamburger samples were inoculated with S. aureus and divided into several groups, including control (no film), chitosan with 7. 5% cellulose nanofiber (Ch-CNF), chitosan with 7. 5% cellulose nanofiber, 0. 8% NBPEO, and 1. 6% NTEO (Ch-CNF-NEO). The samples were preserved in storage conditions (temperature: 4° C), and bacterial count was carried out on days 0, 3, 6, 9, and 12. Data analysis was performed using Bonferroni post-hoc test and repeated measures ANOVA. Results: According to the results, S. aureus count significantly decreased in the treatment groups compared to the control samples. In addition, the maximum reduction rate was observed in the Ch-CNF-NEO treatment (1. 41 log CFU/g) compared to the control samples. Conclution: According to the results, it is offered that nanocomposite film of chitosan with nanoemulsion of essential oils practically be applied in hamburger to enhance its safety against S. aureus.

The present study aimed to assess the effects of various cooking methods (frying with and without oil, microwave cooking, steaming, and roasting) on the proximate composition, fatty acid profile, and lipid oxidation of quail meat. The retention values of nutrients were also determined in order to identify the optimal cooking method. Cooking resulted in moisture loss, and the highest reduction was observed in the steaming and microwave methods. On the other hand, the most significant increase in the protein content was observed in microwave cooking, steaming, and frying with oil, while the highest level of total lipids was denoted in frying with oil. In terms of the fatty acid profile, C18: 1 n-9 increased in all the cooking methods, while C18: 2 n-6 only increased in frying with oil. In addition, C18: 3 n-3 increased in frying with oil and decreased in microwave cooking and steaming. The fried samples absorbed the major fatty acids of the cooking oil. The total amount of saturated fatty acids increased in steaming and decreased in the other methods. The total amount of monounsaturated fatty acids increased in all the cooking methods, and the amount of polyunsaturated fatty acids (PUFAs) also increased in frying with oil, while it decreased in the other methods. The ratio of n-6/n-3 significantly reduced in frying with oil and roasting, and the residual level of PUFAs was higher in the frying methods and roasting compared to the other methods. Furthermore, the studied cooking methods increased lipid oxidation in the cooked samples compared to raw meat, and the highest level of lipid oxidation was reported in frying with oil. With regard to the retention values, frying without oil and roasting were considered the healthiest cooking methods.

Introduction: Shrimps are extremely perishable seafoods, which could threaten human health by causing foodborne diseases and intoxications. Therefore, seafood is generally stored at the temperature of-18˚ C until consumption. The present study aimed to determine the safety of white shrimp in terms of biogenic amine toxicity and investigate some of the rapid chemical indices in this regard. Methods: After preparation, the samples were stored at the temperature of-18° C for six months and analyzed monthly for the levels of trimethylamine nitrogen (TMA-N), biogenic amines (histamine, putrescine, and tyramine), and total volatile base nitrogen (TVB-N). Results: The values of TMA-N and biogenic amines had a rising trend during storage, while TVB-N had fluctuated values. Furthermore, putrescine and TMA-N had strong correlation-coefficients with time (r=0. 933 and r=0. 91, respectively). The biogenic amines remained below the limit value during the six-month storage. Conclusion: Histamine, putrescine, and tyramine did not reach the toxic dose in the study period, posing no significant risk to human health during the appropriate storage of shrimp. Therefore, it is recommended that the values of TMA-N and putrescine be considered as potential quality indicators for frozen white shrimp.

Introduction: Aflatoxin analysis shows that Aspergillus section Flavi strains include mixtures of the strains that are highly toxic to humans with high levels of aflatoxins, while some others produce moderate levels of aflatoxins along with nontoxigenic strains. The present study aimed to evaluate the potential of Aflatoxin production in the Aspergillus section Flavi isolates of pistachio in Iran. Methods: To determine the aflatoxin-producing abilities of Aspergillus section Flavi isolates in pistachio orchards, 180 pistachio nut samples were collected, and fungal isolation was performed by Aspergillus flavus and parasiticus agar (AFPA) medium. In addition, distinct colony morphology in the coconut agar medium, yeast extract sucrose medium supplemented with methyl-β-cyclodextrin, and sucrose low salt medium were used for the distinguishing and screening of toxigenic and atoxigenic isolates. The toxigenicity and aflatoxins production level of the isolates were assayed via thin layer chromatography. Results: In total, 120 isolates of various parts of the pistachio-growing areas of Aspergillus section Flavi were identified by the AFPA, 89. 15% of which were able to produce one or several types of aflatoxins, while 10. 83% of the isolates had no toxin production. Among the investigated isolates, 14. 16% produced aflatoxins such as B1, B2, G1, and G2, while 10. 83% of the isolates produced B1, B2, and G1, 34. 16% of the isolates produced B1 and B2, and only 30% were able to produce the B1 aflatoxin. However, the aflatoxin production of the toxigenic isolates differed within the ranges of 39-21, 548, 37-8, 432, 97-2, 111, and 31-810 ng/g for aflatoxins B1, B2, G1, and G2, respectively. Conclusion: According to the results, 13 out of 120 investigated isolates produced no aflatoxins, and the toxigenicity of the other isolates potentially varied from extremely low to high levels.

Introduction: Quercetin is observed in abundance in Achillea millefolium Linn and it has been employed for the treatment of diseases, infections, as well as health issues. This study examines the individual and combined impact of putrescine and benzyl amino purine (BAP) with the stimulation of quercetin production and the activity of phenylalanine ammonia-lyase (PAL) in Achillea millefolium Linn cultures. Methods: Seedlings with four leaves were cut and transferred to MS basal medium (Murashige and Skoog Basal Medium). At the next stage, different concentrations of putrescine were applied. Quercetin was identified through using HPLC, and the assessment of PAL activity was completed by accounting for the level of cinnamic acid produced at 290 nm. Different experimental data were analyzed after collection using SAS software and Duncan’ s test was employed to compare the means. Results: With the addition of putrescine, the quercetin production, BAP, and PAL activities were remarkably affected. Moreover, quercetin production and PAL activity were enhanced through stimulation applied using putrescine with varying concentrations. When various concentrations of putrescine were applied, the fact was illustrated that 2 mg/L and 1 mg/L experienced the highest amount of quercetin and PAL activity, respectively. Conclusion: This particular finding suggests that combining elicitors and plant growth regulators is a beneficial strategy adopted in enhancing PAL activity and the production of quercetin for in vitro cultures of A. millefolium.

Introduction: In response to concerns arising from the application of synthetic preservatives in foodstuffs, several alternative methods have been proposed, such as the application of natural preservatives. This study aimed to evaluate the potential application of natural-based Lavandula angustifolia essential oil (LEO) as a food preservative by means of in-vitro antimicrobial and antioxidant assays. Methods: The main constituents of LEO were determined by GC-MS method. To assess the antibacterial efficacy of the tested LEO, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the oil were determined against four important foodborne pathogens by microdilution broth method. Finally, DPPH method was used for the evaluation of the antioxidant properties of the LEO. Results: According to the chemical analysis, terpenes, like linalool and 1, 8-Cineol, constitute the main part of LEO. Antioxidant evaluation revealed that the DPPH radicals inhibitory percentage of LEO in concentrations of 40, 80, 120, 160, 200 and 240 (μ g/ml) were 31, 43, 47, 53, 60 and 66 (%), respectively. Regarding antibacterial analysis, the tested LEO could efficiently inhibit and kill the microorganisms including Staphylococcus aureus, Escherichia coli, Bacillus cereus, Salmonella typhimorium and Listeria monocytogenes with the MIC and MBC range of 1. 5 to 4 mg/ml. Conclusion: In conclusion, this work indicates the promising antimicrobial and antioxidant potential of LEO to be considered by food scientists and researchers in future studies.

In the present study, the microencapsulation technique was utilized to improve the stability of crocin in Nabat (rock candy), which is a popular sweet in Iran. For this purpose, crocin was extracted from saffron, and its microcapsules were prepared through the spray drying process. Gelatin solutions with various concentrations (3%, 5%, 7%, and 10% w/v) were used as the wall material. The encapsulated crocin was added to Nabat, and the physicochemical and organoleptic properties of the samples were compared to Nabat containing pure crocin in different storage conditions. The obtained results indicated that increasing the concentration of the wall materials from 3% to 10% significantly increased the particle size of the microcapsules. The optimal efficiency of crocin microencapsulation was observed at the gelatin concentration of 5%. In addition, a significant difference was observed in the color properties of Nabat containing pure and encapsulated crocin during storage. Therefore, crocin microencapsulation could preserve the sensory properties of the samples. Considering the significant effect of light on the stability of crocin, Nabat containing this substance should be protected from direct light by hermetic packaging.

Introduction: Allium hirtifolium (Persian shallot) belongs to the Alliaceae family. Recently, the ethanolic extract of Persian shallot has significant activity against some important clinical pathogens. The present study aimed to evaluate the in-vitro antibacterial potency of the ethanolic extracts of Persian shallot (Iranian Moosir) combined with common antibiotics against five clinically important antibiotic-resistant pathogens. Methods: Antibacterial activities were determined using the disc-diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also evaluated using the broth microdilution method for the extract and selected antibiotics. In addition, the checkerboard technique was applied to evaluate the combined effects of the extract and antibiotics. Results: The MICs of the extract and antibiotics were within the ranges of 4-16 mg/ml and 4-128 μ g/ml, respectively. The MBCs of the extract and antibiotics were within the ranges of 8-16 mg/ml and 8-128 μ g/ml, respectively. The results of the checkerboard technique showed that amikacin and trimethoprim/sulfamethoxazole had synergistic effects, while levofloxacin, imipenem, and vancomycin exerted antagonistic effects on the isolates in combination with the extract. Conclusion: The in-vitro application of Persian shallot extract combined with amikacin and trimethoprim/sulfamethoxazole is recommended to effectively inhibit the growth of five clinically significant antibiotic-resistant pathogens.

Introduction: The aim of this study was to investigate the chemical, textural and sensory properties of some fruit-added ice creams. Methods: For this purpose, 6% fruit puree (blackberry, raspberry, kiwi, banana, and sour cherry) added to the ice cream formulation and the produced ice creams were stored at-18° C for 60 days. Results: Titration acidity, pH, colour (L*, a*, b*), first drip time, melting rate, overrun, viscosity, texture, total phenolic content (TPC) values were determined. Fruit-added ice creams had significantly higher dry matter content than control samples (p<0. 05). The overrun rate of ice creams decreased with the addition of fruit although the difference between ice cream varieties was insignificant (p>0. 05). It was observed that titration acidity and stickiness values of ice creams generally increased while pH and hardness values decreased with fruit addition (p<0. 05). At the end of the storage period, the first drip time of the ice creams decreased and the melting rates increased. However, no statistically significant difference was observed between the storage periods (p>0. 05). Although the viscosity values of ice cream mixes showed variability, no significant difference was determined between ice cream samples (p>0. 05). Compared to the plain ice cream (DS), the addition of fruit puree to the ice cream increased the TPC (p<0. 05). No statistically significant difference was found between storage times of ice cream samples in terms of pH, titration acidity, colour values, first drip time, melting rate, viscosity, and TPC (p>0. 05). Sensory analyses indicated that banana (DM) and blackberry (DB) added ice creams were the most popular varieties in terms of general acceptability. Conclusions: Current study suggests that the natural antioxidants, minerals, vitamins, nutritional fibers and natural color ingredient in fruits increase the nutritional values of ice cream as well as its attractiveness to people.

Introduction: Chocolate is a popular food product. White chocolate is produced extensively and has lower functionality compared to other chocolates. The present study aimed to characterize white chocolate enriched with free or encapsulated pomegranate extract. Methods: To increase the functionality of white chocolate, pomegranate extract was added in the free or encapsulated forms at various concentrations (1, 2, 3, 4, and 5 g/200 g). The coacervation was performed for the encapsulation of pomegranate extract. The quality parameters of the chocolate samples were also evaluated, including the color index, melting behavior, flow behavior (rheometer and scanning electron microscopy), particle size distribution, texture analysis, and organoleptic properties. Other analysis included the determination of the total phenolic compounds and antioxidant properties of the samples. Results: The addition of pomegranate extract (free/encapsulated) decreased Tonset, Tpeak, and  H of white chocolate compared to the control samples. In addition, the added pomegranate extract reduced the casson yield stress, while it increased casson viscosity. The extract also changed the color indices and particle size distribution (P<0. 05). The white chocolate samples containing pomegranate extract (free/encapsulated) had a higher phenolic content and antioxidant activity than the control samples. Moreover, sensory properties were affected by chocolate formulation, and the samples containing encapsulated pomegranate extract had superior organoleptic properties compared to the samples with free pomegranate extract. Conclusion: According to the results, free or encapsulated pomegranate extract could enhance the functionality of white chocolate in term of antioxidant activity. Furthermore, organoleptic properties were affected by chocolate formulation, and the samples containing encapsulated pomegranate extract had better organoleptic properties compared to those containing the free form of the extract.