فصلنامه پژوهش و نوآوری در علوم و صنایع غذایی
سال یازدهم شماره 2 (تابستان 1401)

Encapsulation in liposome structure can be used as a protective carrier system for bioactive compounds during processing and storage under different conditions. Phycobiliproteins (PBPs) extracted from algae with antioxidant, antimicrobial, anti-cancer and anti-inflammatory properties can be applied to produce raw materials for functional foods. Therefore, in the present study, phycobiliprotein pigment was extracted from Gracilaria algae and the amounts of pigment was investigated. Also, nanoliposomes containing PBPs coated by chitosan (0, 0.5, 1 and 1.5%) were prepared and their physicochemical properties, antioxidant and antimicrobial activity were evaluated. The mean diameter of nanoliposomes and Polydispersity index (PDI) ranged from 336.9 to 577.7 nm and 0.25 to 0.28 in nanocarriers, respectively. The highest values of nanoliposome encapsulation efficiency of PBPs (83.98%) were obtained under optimal conditions in nanoliposomes with 1.5% chitosan coating. The results showed that the antimicrobial activity of the treatments increased significantly after encapsulation in the nanoliposome. In addition, the antioxidant activity of PBPs increased significantly after nanoencapsulation in liposomes. So that the EC50 level decreased to 81.27 and 107.67 ppm in DPPH and ABTS tests in nanoliposomes with 1.5% chitosan coating, respectively. Based on the findings of this study, it can be realized that nanocoating with chitosan effectively increases its stability, antimicrobial and antioxidant properties. Therefore, in order to increase the stability of natural compounds during different processes, it is recommended.

Nowadays, the food industry is looking for new ways to reduce the levels of saturated and trans fatty acids in processed foods and to produce suitable fat substitutes for high-fat products that provide all or some of the functional properties of fats and have health benefits. In this study, sesame oil in gel matrices for the production of inulin-based oil bulking agents in three levels (0.5 to 1.5%), Persian gum (1 to 2.5%) And alginate was used at three levels (0.5 to 1%) as a new way to improve the fat content of pragmatic food products. Oil migration percentage, thermal stability, color parameters such as L*, a*, and b*, rheological properties such as hardness, adhesiveness, consistency, adhesion force of oil bulking agents produced were investigated. The two-phase structured system was optimized by the response surface method with three-variable responses in maximum thermal stability, lowest oil migration percentage, best color and desirable texture properties, and optimal values in percent concentrations (1.32) of Persian gum (1.5) inulin and (0.96) sodium alginate were obtained. In the study of regression model, hardness, consistency, brightness and yellow color with an explanation coefficient above 85% showed a good fit of the model compared to the experimental data.

The aim of this study was to produce electrospun gliadin nanofibers containing Zataria multiflora Boiss essential oil (ZMEO) (5, 10 and 15%, w/w) to create active antimicrobial mats. The minimal inhibitory concentration (MIC) and minimal bactericide concentration (MBC) of essential oil were measured. The ZMEO loaded gliadin nanofibers were characterized for physicochemical, antioxidant and antibacterial activity. Results according to the MIC and MBC revealed that the ZMEO showed the most remarkable bactericidal effect. The nanofibers showed an encapsulation efficiency close to 95% and the presence of ZMEO led to increased contact angle and opaque. ZMEO increased the absorption of color in the visible region, which in turn led to increase of the b* parameter but reduced a* and L* parameters. The nanofibers’ antimicrobial activities were induced by incorporating ZMEO, and Bacillus subtilis was the most sensitive bacterium to ZMEO-containing nanofibers, while Salmonella tiphi was the most resistant. The nanofibers incorporating ZMEO showed good antioxidant properties; this effect was greatly improved when the proportion of added ZMEO was 15%. Then, efficacy of bioactive nanofibers included 5, 10 and 15% (w/w) ZMEO to reduce microbial growth (Listeria monocytogenes) of smoked salmon fish fillet during chilled storage was evaluated; the results indicated that its final population was reduced to about 2.5-3 Log cycles after 16 days of storage at 4 °C in presence of ZMEO, compared with negative control mats produced without the ZMEO. These results suggest that the developed gliadin nanofibers with active substance could be used in designing antimicrobial packaging materials.

The aim of this study was to produce low fat muffins using oleogels using carnauba wax and grape seed oil. The oil in the muffins formulation was replaced with various levels (0 and 100%). The rheological properties of different dough samples showed that all samples had shear-thinning behavior. By increasing the percentage of oleogels, the density of the dough increased significantly (P<0.05), but increasing the oleogel to 50% compared to the control sample did not have a significant effect on the density of the dough. Water activity of muffin cake samples containing oleogel were higher than the control sample. With increasing the percentage of using oleogels to the level of 50%, the specific volume of cakes increased. The use of oleogel up to 50% level had no significant effect (P>0.05) on L* index. With increasing the percentage of using oleogels to the level of 50%, the hardness decreased. However, further increase of oleogels from 50 to 100% significantly (P<0.05) led to an increased hardness. Increasing the storage time significantly increased hardness (P<0.05). Samples containing oleogel from 10 to 50% in terms of sensory properties were not significantly different from the control sample (P<0.05) but by increasing the percentage of oleogel application from 50% and above, it led to a significant decrease in all sensory properties of muffin samples compared to the control sample. Therefore, in general, a sample containing 50% oleogel based on carnauba wax and grape seed oil instead of oil can be selected as the superior sample.

Chicken fillet is one of the most popular food products made from chicken. Microbial growth and oxidation of lipids are the primary factors of spoilage of this product in refrigerated conditions. Chicken fillet samples were prepared in the form of a control sample and a treatment with grape seed essential oil and 4 treatments with concentrations of 1, 2 and 5% grape seed essential oil nanoemulsion and were kept in a refrigerator (4 and 8 °C) for 14 days. During this period, all the samples were evaluated and compared by performing microbial, chemical and sensory tests at different time intervals. Two-way analysis of variance was used to analyze the data, and Duncan's multiple range test was used to compare their averages. The results showed that the samples treated with different concentrations of grape seed nanoemulsion compared to the control sample had lower bacterial counts and lower total volatile nitrogen and proxid value throughout the study period. Samples treated with 5% concentration of grape seed essential oil nanoemulsion were more effective in increasing shelf life compared to concentrations of 1 and 2%. Also, the overall acceptance of the sample with 5% essential oil nanoemulsion up to day 7 had a score of 3.12±0.11. Therefore, it can be concluded that grape seed essential oil nanoemulsion can increase the shelf life of fresh packaged chicken fillet in refrigerated conditions by delaying microbial and chemical spoilage and improving sensory characteristics.

This study aimed to produce Lactobacillus Plantarum bacteria and the Echinophora platyloba extract nanoemulsions by sodium alginate to enrich dairy dessert based on camel milk. For this, the amount of 0.6, 1.25, and 2.5% Echinophora platyloba extract was added to dessert. Extract nanoemulsion, dairy desserts physicochemical, microbial, and overall acceptance was tested. The viability of probiotic bacteria was performed on 1, 11, and 21 days in three replications. The results showed the formation of fine and uniform particles. The nanoemulsion of the extract caused more preservation of phenolic compounds and thus increased their antioxidants. The diffusion result shows that Escherichia coli and Candida albicans were the most resistant and sensitive microorganisms, respectively. The nanoemulsion of the extract showed the MIC and MBC on Escherichia coli, Candida albicans, and Aspergillus niger. However, no statistically significant difference was observed between the MIC of the free and nanoemulsion extract on Staphylococcus aureus. Dairy desserts test showed an increase in acidity, ash and overall acceptance, a decrease in pH and moisture with an increase in the concentration of the fine-grained extract, and the storage time.  The used extract had no significant effect on the amount of fat and protein in the treatments. The microbial test showed that bacteria did not grow against the microencapsulated extract. An increase in the viability of probiotic bacteria in dairy desserts was also reported. Therefore, dessert milk based on camel milk can be introduced as a beneficial probiotic product.

Adding various substances to the chewing gums has led to the formation of new applications for them, which include drug delivery and oral and dental hygiene. In this research, the physicochemical and rheological properties of charcoal chewing gum were studied using chemical analysis and sensorial methods. The results of this study show that the addition of activated charcoal in the studied chewing gums has a Longer-lasting flavor and more saliva secretion. Longer-lasting flavor in charcoal chewing gum increases the acceptance and willingness to keep charcoal based chewing gums for panelists. In line with the results of sensory evaluation, histometric analysis of charcoal and non-charcoal based chewing gums shows the same texture profile against pressure on both types of chewing gum, with the difference that the maximum pressure tolerance threshold in charcoal based chewing gums is higher than in chewing gums without charcoal. In general, it seems that increasing the susceptibility along with increasing saliva secretion and increasing the pH in general create a suitable substrate for more activated charcoal in chewing gum and therefore the efficiency of charcoal chewing gum to absorb unwanted substances such as dyes, microbes and viruses in saliva. Therefore, it is expected that the use of charcoal gum by reducing the concentration of microbes and viruses in saliva can have a great impact on oral health, dental protection, general health, and reduce the prevalence of infectious and viral diseases.

Spirulina is blue-green microalgae as an excellent source of protein and natural food colors such as phycobiliproteins, chlorophylls. So, extraction of these bioactive compounds is important. In this study, the mechanical treatments (freeze-defreeze, homogenization, ultrasonic), and chemical treatment (soaking in ethanol and water) were performed and extraction and separation of protein and chlorophyll from Spirulina microalgae were done in the separate and continuous way of Spirulina mass. The yield of extracted chlorophyll and protein, the absorption spectrum of the samples (200-800 nm), and the amino acid profile of the extracted proteins by the selected treatments were tested. According to the results, the extraction yield of chlorophyll in a continuous way was higher than in a separate method, and extraction with ethanol in both separate and continuous ways was a suitable solvent and showed higher efficiency (P<0.05). The freeze-defreeze cycle was also effective in chlorophyll extraction. The protein extraction, homogenization, and ultrasound treatments were acted more appropriately to mechanically break down cell walls and increased extraction efficiency (P<0.05). In the same conditions, the continuous way of extracting chlorophyll and protein showed higher efficiency than the separate way, and homogenization and ultrasound are recommended and ethanol was suitable solvent in chlorophyll extraction and the freeze-defreeze treatment was appropriate at split the cell wall.