Research and Innovation in Food Science and Technology
Year:2020 | Volume:9 | Issue:1 |Papers Count:8

Enzymetic modification of proteins in order to break down specific peptide bonds and protein modification is widely used in the food industry. In this research, protein of faba bean seeds was hydrolyzed using alcalase and trypsin enzymes at three concentrations (1, 2 and 3%) and reaction times of 1-6 h at optimal temperature and pH of enzymes (50 and 37 ° C, pH 8. 5 and 7, respectively). Hydrolysis degree, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and iron chelating activity of hydrolyzed proteins were investigated. The results showed that the degree of hydrolysis increased with increasing reaction time and concentration of alcalase and trypsin enzymes. The time of hydrolysis and type of enzyme has a significant effect on the degree of hydrolysis, the antioxidant and chelating activity of the faba bean protein hydrolysates (P<0. 05). The proteins hydrolyzed by alcalase at concentration of 3% and reaction time of 3 h had the highest antioxidant (75. 41%) and metal chelating activity (55. 95%). At the 1 and 2% concentration of trypsin, the highest DPPH radical scavenging activity was observed at 4 h which was 42. 38 and 53. 7 %, respectively. The most metal chelating activity in trypsin hydrolyzed treatments was observed in a reaction time of 2 h, after which the activity decreased. DPPH radical scavenging and metal chelating activity increased with increasing enzyme concentration. The results showed that alcalase have more efficiency in the production of anti-oxidant peptides compared to the trypsin.

In this study alyssum homolocarpum seed gum (AHSG) nanocapsules containing D-limonene were fabricated by electrospraying process. For this purpose, D-limonene emulsions with constant AHSG (0. 5% w/w) and two different flavor concentrations (10 or 20% based on gum weight) were prepared. The effects of physical properties of emulsions (rheological properties, droplet size, surface tension and electrical conductivity) on the morphology of capsules were studied. The results indicated that the droplet size and electrical conductivity of emulsions was mainly affected by concentration of D-limonene. Consequently, morphology and particle size of nanocapsules obtained from two emulsions, were somewhat different due to their difference in flavor content. FE-SEM images confirmed the success of electrospraying process for production of round and smooth AHSG nanocapsules with narrow size distribution. AHSG nanocapsules showed high encapsulation efficiency (more than 87%). Stability assay revealed a relatively good storage stability of encapsulated D-limonene and the maximum loss in 90 days was 11. 67%. The release of D-limonene from AHSG nanocapsules was performed quickly, completely and fairly uniform due to the small and uniform size of particles. The kinetic modeling indicated that the data of D-limonene release in both artificial saliva and deionized water media were well fitted to the Korsmeyer-Peppas models.

In this research, the physicochemical and antimicrobial properties of propolis from honeybee beehives around Mashhad and the content of active compounds in propolis were determined by high pressure liquid chromatography (HPLC) both quantitatively and qualitatively. Physicochemical properties of the propolis sample (such as ash, moisture, soluble solids and insoluble solids and existing metal elements) were measured. The total phenolic and flavonoids compounds in the ethanolic extract of propolis were 40. 126 mg/g (gallic acid) and 26. 46 mg/g (quercetin), respectively. Antimicrobial tests showed that the minimum inhibitory concentration (MIC) of the extract against Staphylococcus aureus was 100 mg/mL, while in the applied concentration MIC did not achieve against Escherichia coli. Also, the results of the minimum bactericidal concentration (MBC) test indicated that propolis extract on Staphylococcus aureus had only inhibitory effects. Evaluation of the content of phenolic and flavonoid compounds in propolis extract by HPLC indicated that the flavonoid compounds included flavones (13. 33 mg/g), flavonoids (6. 375 mg/g), flavonols (8. 235 mg/g) and flavanones (16. 825 mg/g). Based on the results, propolis can be used in various food and pharmaceutical industries.

The aim of this study was to evaluate the effect of incorporation of eggplant puree (0-45%) on physicochemical properties (pH, acidity, color and syneresis), sensorial parameters (odor and taste, color, and texture) and survival of probiotics in yogurt after 1, 4, 7, 10 and 14 days of storage. Furthermore, Analytic Hierarchy Process (AHP) was used to determine the best probiotic eggplant yogurt according to the assessed parameters. The results showed that by increasing the amount of eggplant puree, the extent of acidity, syneresis and lightness (L*) decreased while the pH increased. Incorporating eggplant puree caused significant (P<0. 05) reduction of probiotic bacteria at the beginning of storage time. However, during the storage period this status contrarily changed, in such a way that yogurt samples containing a higher concentration of eggplant puree at the end of storage had a higher count. This was probably due to prebiotic effect of eggplant puree and the lower pH of yogurt sample. According to data analysis by AHP, yogurt sample contained 30% of eggplant puree with the weight of 0. 171 being the best formula compared with the others. The results showed that incompatibility rate was 0. 08 and as this value was lower than 0. 1, the obtained results had an acceptable reliability and credibility. Based on the results of this research, the manufactured eggplant probiotic yogurt having an acceptable sensory and probiotic properties may be introduced as a functional food product. Furthermore, due to prebiotic capability of the eggplant puree, it could be used in various probiotic products.

In this study, the carbohydrates material include Arabic gum (0-100%), maltodextrin (0-50%) and inulin (0-50%) were used as wall compounds for the microencapsulation of cardamom essential oil. A simple-central mixture design was used to experiment design, to optimize and find the best combination for maximal release in the mouth media. The aim of this study was microencapsulation of cardamom oil active ingredients and the effect comparison of adding maltodextrin and inulin to Arabic gum as coating materials on the responses involve the microencapsulation yield, and release of active ingredients and recovery of powder. In this study, the relationship between glass transition temperature and the release of essential oils of cardamom essential oil was investigated in saliva. The results showed that the optimal combination of Arabic gum, maltodextrin and inulin with ratios of 66. 8: 33. 2: 0. 0, respectively, under these conditions, the microencapsulation yield of the essential oil, alpha-triphenyl acetate and 1 and 8 cineol were 83. 57, 91. 79 and 90. 87%, the release of the active ingredient was 93. 27% and the powder recovery was 67. 72%. The glass transition temperature of the optimal combination was 42. 9 ° C, which was a suitable temperature for preserving the active ingredients at ambient temperature and release in saliva. According to the results of this study, the cardamom essential oil optimal combination can be successfully applied in the products as chocolate, candy, sugar cubes, without the release of active ingredients at ambient temperature and with the rapid and high release in the mouth media.

In this research, in the preparation of ice cream, cow's milk and/or soy milk at a ratio of 100: 0, 90: 10, 80: 20, 70: 30, 60: 40 and 50: 50 were substituted. Then, characteristics such as pH, viscosity, overrun, melt resistance and sensory properties were tested. The results indicated that by increasing the cow's milk replacement with soy milk, pH, viscosity and melting resistance significantly increased; however, overrun decreased (P<0. 05). The taste and overall acceptability were reduced without the use of vanilla flavor, though no significant difference was observed after adding one percent of vanilla to 40% of the replacement level. The ice cream mixes were spray-dried in a pilot plant spray dryer. The powders were reconstituted and converted into ice cream and their physicochemical and sensory properties were measured and compared with primary mixes. The results showed that the pH, viscosity, overrun and melting resistance of the powder samples compared to the primary specimens significantly decreased, although significant changes in sensory features were not observed when using vanilla (P<0. 05).

Microencapsulation of sodium selenite (15000 ppm) was carried out, comprising the following combination: Arabic gum (25, 26, 27, 28 and 29%) and a proportionate amount of Farsi gum (1, 2, 3, 4 and 5%) and using the solvent evaporation method, where the Ethanol purity percentages (80, 85, 90, 95 and 100%) and the ratio of solvent to the mixture [gum+sodium selenite] was 10: 1. Subsequently, utilizing the response surface methodology (RSM) software, the optimization was carried out based on the highest efficiency of encapsulation and the smallest size of particles. Two formulas of the optimization were chosen for this study comprised the following: the optimization formula 1 (efficiency 89. 5%, particle-size 44. 6μ m, Arabic gum 27%, Farsi gum 3%, and the percentage of ethanol purity 94%) and the optimization formula 2 (efficiency 86%, particle-size 48. 5 μ m, Arabic gum 29%, Farsi gum 1%, and the percentage of ethanol purity 89%). Ultimately, the two selected optimal (180. 6 ppm), the synthetic antioxidants butylated hydroxyanisole (BHA) (200 ppm), and the un-microencapsulated sodium-selenite(8. 6 ppm) were added to antioxidant-free soybean oil and then were placed at the 55  C for (0, 23 and 46 days) equal to 20  C (0, 180 and 360 days). The oxidation indices were compared with soybean oil that did not contain anti-oxidant. A direct relation was detected between the concentration of Arabic gum and alcohol purity percentage with the efficiency of the encapsulation (94. 63%). A reverse relation was detected between the concentration of Arabic gum and alcohol purity percentage with the particle-size (37. 5 μ m). The effective and propositional treatments are presented including, Opt1, Opt2, BHA, un-microencapsulated sodium-selenite and blank (antioxidant-free), respectively.

The bitterness of citrus juice is one of the most important factors in the reduction of marketability in juice industry. Limonin and Narengin are known as two important compounds in bitter citrus juice during storage. Therefore, various processes, including chemical, microbial and enzymatic methods, have been used to reduce these bitter compounds. The purpose of this study was to investigate the effect of adding Pseudomonas putida bacteria on the reduction of the level of limonin and also the measurement of physicochemical and organoleptic properties. Pseudomonas putida bacteria with two concentrations of 102 and 104 cfu/mL as a causative agent of orange and grapefruit concentrate were studied. Also, the physicochemical properties of concentrates were measured at 120 h (growth time and bacterial activity). The results showed that the growth rate of bacteria had a significant effect on the reduction of lemonin, pH and turbidity levels (P<0. 05). Also, it has a significant effect on increasing the acidity of the treatments (P<0. 01). After pasteurization and inactivation of Pseudomonas putida bacteria, to ensure that bitterness is not rejected the specimens were incubated at 40 ° C for 45 days and sensory characteristics were measured on days 0, 15, 30 and 45. Among the samples, T4 (orange concentrate + 104 cfu/mL) and T6 (grapefruit concentrate + 104 cfu/mL) treated with the lowest microbial growth rate in 120 h and also, in terms of general acceptance and taste, it has more points than other samples during 45 days of storage were identified as superior samples.