Bacterial nanocellulose-based nanopaper activated by ß-cyclodextrin/ Salvia officinalis essential oil complexes for shelf life extension of shrimp.

Active bacterial nanocellulose (BNC) nanopapers containing Salvia officinalis essential oil (SEO) in free form and encapsulated with ß-cyclodextrin (ßCD) were prepared, and their effect on the shelf life extension of shrimp was investigated. The GC-MS analysis of the SEO indicated the presence of various active compounds such as Thujone (21.53 %), Ledol (12.51 %) and Eucalyptol (11.28 %) in the essential oil composition. The cytotoxicity of the SEO and SEO-ßCD complexes in the L929 cell line was quite low. FTIR analysis revealed new interactions in the nanopapers containing SEO-ßCD complexes. Microscopic images showed that SEO-ßCD complexation improved the surface morphology of the BNC nanopapers, whereas free SEO had a negative effect. X-ray diffraction patterns of the nanopapers showed higher crystallinity of the SEO-ßCD containing nanopapers than that of the SEO-incorporated nanopapers. Moreover, the addition of the SEO-ßCD complex improved the thermal properties of the BNC nanopaper. Water contact angle analysis showed higher hydrophobicity of the samples containing free SEO than that of the other samples. Both SEO-ßCD and free SEO increased the elongation at break and decreased the tensile strength of the nanopaper. The prepared active films showed a greater antimicrobial effect on L. monocytogenes than on E. coli. The results showed a higher antioxidant capacity of the free SEO-containing nanopapers (58-78 %). The desirable effects of the active nanopapers on shrimp preservation were demonstrated by the results obtained for the microbial load, pH, and volatile nitrogen content of the product. The results demonstrate the potential of the prepared BNC active nanopapers for use in active antioxidant/antimicrobial food packaging.

Characterization of electrospun nanofibers and solvent-casted films based on Centaurea arvensis anthocyanin-loaded PVA/κ-carrageenan and comparing their performance as colorimetric pH indicator.

In this research, PVA/Ò -carrageenan-based colorimetric indicators incorporated with Centaurea arvensis anthocyanin (CAE) were fabricated by two electrospinning and solvent casting methods and their performance as pH indicators were assessed. Chemical immobilization of CAE on PVA and PVA/Ò -carrageenan matrixes was approved by FT-IR analysis. According to SEM images, Ò -carrageenanaddition improved the homogeneity of films and decreased the diameter of nanofibers. The crystalline structure and thermal properties of polymeric matrixes were affected by anthocyanin incorporation. CAE had an adverse effect on mechanical properties of films and nanofibers. The preparation method and type of solid matrix affected the responsiveness and the tonality of responded color. Electrospun nanofibers showed high responsiveness (10 s) than colorimetric films (15-40 min) to pH changes. The indicators displayed color variations from heather violet to green over the 2-12 pH range. The designed indicators have potential to be applied as visual pH label in food intelligent packaging.

Amaranth selective hydrolyzed protein influence on sourdough fermentation and wheat bread quality.

Amaranth selective hydrolyzed protein (ASPH) may improve sourdough properties and bread quality. In this regard, this study focused on investigating the influence of protein hydrolysates on sourdough fermentation and bread properties. Based on the findings, ASPH further increased Lactobacillus plantarum and Saccharomyces cerevisiae growth in sourdough compared with amaranth protein isolates and amaranth flour. ASPH at 5 g/kg resulted in sourdough with higher pH and total titratable acidity (TTA) after 20 h of fermentation at 30°C. The prepared sourdough using APH (S-ASPH) at 3 g/kg increased the specific volume (4.57 ml/g) and TTA (4.76 ml) while decreasing water activity, hardness, cohesiveness, and chewiness of the bread (S-ASPH-B) compared with the control. Moreover, transition temperature and enthalpy reduced whereas sensory properties and shelf life represented an increase with S-ASPH addition. Overall, the obtained data indicated the improvement of bread quality by S-ASPH sourdough.

Fabrication and characterization of sunflower protein isolate nanoparticles, and their potential for encapsulation and sustainable release of curcumin.

In this research, first, the effects of two desolvating agents (ethanol and methanol) at three temperature values (4, 25, and 50 °C) on the fabrication of sunflower protein isolate (SnPI) nanoparticles were studied using a desolvation method. Second, the ability of the nanoparticles to encapsulate curcumin was investigated. Results showed that ethanol led to smaller nanoparticles compared to methanol as the desolvating agent at 4 and 50 °C. However, at 25 °C, ethanol formed the most uniform nanoparticles with the lowest polydispersity index (0.188 ± 0.091) and particle size of 174.64 ± 30.61 nm. The encapsulation efficiency was in the range of 39.1 to 95.4% according to the fabrication condition and curcumin-to-protein mass ratio. A biphasic trend of curcumin release from nanoparticles was observed; in which, over 50% of curcumin was released from the curcumin-loaded nanoparticles in the first 2 h, which is attributed to the burst effect of the protein matrix.

Optimization of low-fat meat hamburger formulation containing quince seed gum using response surface methodology.

In the present study, feasibility of low-fat hamburger production by partial replacement with quince seed gum (QSG) was investigated. The effects of different QSG levels (1.2, 2.4, 3.6, and 4.8 wt%) on cooking loss, water holding capacity, lipid oxidation, antioxidant activity, and hardness of hamburger were investigated during a period of 9 days. The optimization was carried out based on minimum cooking loss, lipid oxidation, and maximum water holding capacity, antioxidant activity, and tissue hardness. Optimum conditions were achieved as 3.26% oil, 4.73% QSG, and 8.25th day of storagability. According to the optimum conditions, values for cooking loss, water holding capacity, lipid oxidation, free radical scavenging, raw hamburger hardness, and fried hamburger hardness were as 13.80%, 55.61%, 0.59 mg MDA/Kg, 48.12%, 2.99 N, and 8.66 N, respectively. Overall acceptability of optimized hamburgers was better and more acceptable than control ones.

Evaluation of thermal stability of confectionary sunflower protein isolate and its effect on nanoparticulation and particle size of the produced nanoparticles.

In this study, the effect of different defatting conditions on heat stability of confectionary sunflower protein isolate (SnPI) and the particle size of the produced nanoparticles was investigated. The evaluated factors included temperatures of defatting (40, 50, and 60 °C), time of defatting (2, 6, and 10 h), and the amount of activated carbon (0, 25, and 50% of sample weight). The results of the central composite design showed a significant effect (P < 0.05) among the studied factors, where denaturation temperature and particle size of SnPI nanoparticles were found to be in the ranges of 75.05-89.12 °C and 268-1594 nm, respectively. Moreover, the interaction of activated carbon with temperature and time of defatting proved to be influential factors for the heat stability of confectionary SnPI.

Oxidation phenomena and color properties of grape pomace on nitrite-reduced meat emulsion systems.

The present study focuses on the effect of different levels of red grape pomace (1 and 2%, w/w) on the color changes, lipid oxidation (TBARS), antioxidant activity, microbial counts, total phenol content and sensory attributes of the sausages formulated with various levels of sodium nitrite (30, 60 and 120mg/kg). It was found that the addition of grape pomace (1%, w/w) in combination of reduced nitrite levels to the beef sausage samples reduced TBARS content and the degree of lipid oxidation. Antioxidant activity and total phenol contents were further evaluated based on DPPH scavenging activity method. A significant reduction in lightness (L*) and yellowness (b*) of systems containing grape pomace was observed, following by an increase in the oxidative stability and the radical scavenging activity. Acceptability of beef sausages was not significantly (P>0.05) affected by the addition of grape pomace and had relatively greater scores from a sensory point of view.

Enzymatic cross-linking of soy proteins within non-fat set yogurt gel.

Soy proteins as the health-promoting ingredients and candidate fat substitutes in dairy products are good substrates for the cross-linking action of the enzyme transglutaminase. Non-fat set yogurt samples were prepared from the milks enriched with soy protein isolate (SPI) and/or treated with the enzyme transglutaminase. The highest titrable acidity was recorded for the yogurt enriched with SPI and treated with the enzyme throughout the cold storage for 21 d. SPI-enrichment of yogurt milk increased the water holding capacity. Although enrichment with SPI did not influence the count of Streptococcus themophilus, increased that of Lactobacillus bulgaricus ∼3 log cycles. The enzymatic treatment of SPI-enriched milk however, suppressed the bacteria growth-promoting influence of SPI due probably to making the soy proteins inaccessible for Lactobacillus. SPI-enrichment and enzymatic treatment of milk decreased the various organic acids content in yoghurt samples; influence of the former was more significant. The cross-linking of milk proteins to soy proteins was confirmed with the gel electrophoresis results.