Microencapsulation of microbial canthaxanthin with alginate and high methoxyl pectin and evaluation the release properties in neutral and acidic condition.

Canthaxanthin (CX) is an orange-red keto-carotenoid with high antioxidant activity. This functional pigment is sensitive to oxygen, light, pH and heat. In this study, CX was produced by the Dietzia natronolimnaea HS-1 and was encapsulated in Alginate (Alg) and Alg-high methoxyl pectin (HMP) through O/W/O multiple emulsion/external gelation method to developed resistant microparticles among acidic and neutral pHs. Results showed that initial CX concentration had a significant influence on total CX (TCX), surface CX (SCX), microencapsulation efficiency (EE) and particles size. The highest EE% for Alg (60.21 ±â€¯0.18) and Alg-HMP (70.60 ±â€¯0.68) were obtained with CX initial concentration of 11 and 18 µg/mg, respectively. Alg microparticles showed smaller size compare to Alg-HMP microcapsules. Presence of CX in microparticles and good antioxidant activity was confirmed by FT-IR spectroscopy and DPPH assay, respectively. CX in vitro release was 66% and 49% in acidic condition and 76% and 50% in neutral condition for Alg and Alg-HMP, respectively. Thus, Alg-HMP-CX18 microparticles were selected to be used in both neutral and acidic foods such as milk and fermented milks products as an antioxidant and a colorant agent.

A practical optimization on salt/high-methoxyl pectin interaction to design a stable formulation for Doogh.

Doogh is a traditional Iranian fermented drink. Response surface methodology-central composite design (RSM-CCD) was used to determine optimum formulation for the production of Doogh stabilized by high methoxyl pectin (HMP). The effects of HMP (0.28-0.42% wt) and salt (0.4-1.1% wt) concentrations on the stability, viscosity, volume-weighted (D43) and surface-weighted (D32) mean diameters and Span were investigated. Graphical response surface plots were applied to locate the optimum point. The optimum composition for stable Doogh production was found to contain (% wt) HMP 0.4 and salt 0.62. These optimum conditions yielded the stability of 96.34%, viscosity of 2.05 mPas, D43 of 11.922 µm, D32 of 0.966 µm and Span value of 2.140. There was no significant difference between the physical, rheological and sensory attributes of Dooghs produced under optimum conditions and commercial samples.

Scrutinizing the different pectin types on stability of an Iranian traditional drink "Doogh".

Doogh is a fermented dairy drink which is highly consumed by Iranian people. Stability of this healthy drink was investigated in terms of sedimentation rate, viscosity, density and particle size characteristics including surface-weighted mean diameter (D32), Span and particle uniformity. Eight treatments were performed as randomized complete block design (RCBD) with three replications. Three types of pectin (high methoxyl pectin (HMP), grapefruit-seed extract pectin (GSEP) and amidated pectin (Ceamsa pectin (CSP)) at a constant concentration (0.35%w/w), three levels of salt (0.50, 0.75 and 1.00%w/w) and two dry matter contents (DMCs, 4 and 5% w/w) were used to produce the Dooghs. The results showed that the maximum stability and viscosity, and the minimum D32 were obtained by application of CSP, GSEP and HMP, respectively (p<0.05). Pectin type had no significant difference on the density values of Dooghs. The lowest sedimentation rate, viscosity, density and D32 were achieved in the minimum concentrations of salt and dry matter. The ANOVA analysis also revealed that the interaction of pectin type, salt concentration and DMC had a significant effect on the Span and particle uniformity. A maximum physical stability was found for the prepared samples with 0.35%w/w CSP, 0.5%w/w salt and 4%w/w dry matter. Evaluation of sensory attributes also confirmed that this formulation had the highest overall acceptability value.

Ultrasound-assisted formation of the canthaxanthin emulsions stabilized by arabic and xanthan gums.

There is interest in incorporating canthaxanthin (CTX) into food emulsions due to its high potential health benefits. The used CTX in this study was produced by the bacterium of Dietzia natronolimnaea HS-1. Then, the influence of main emulsion components (gum arabic (GA), xanthan gum (XG) and coconut oil (CO)) on the surface-weighted mean diameter (D32), polydispersity index (PDI), specific surface area (SSA) of droplets and density of the emulsions containing CTX was optimized using response surface methodology (RSM). Polynomial equations between the responses and independent variables were derived. The linear effect of GA had a significant (p<0.0001) term in all reduced models. The optimal formulation for emulsions was composed of GA content of 9.85% (w/w), XG content of 0.13% (w/w) and CO concentration of 3.50% (w/w). This optimum formulation yielded D32 of 0.752 µm, PDI of 1.533, SSA of 9.995 m(2)/ml and density of 1.0357 g/cm(3).

Psyllium husk gum: an attractive carbohydrate biopolymer for the production of stable canthaxanthin emulsions.

The physical stability of the ultrasonically prepared emulsions containing canthaxanthin (CX) produced by Dietzia natronolimnaea HS-1 strain was maximized using a face central composite design (FCCD) of response surface methodology (RSM). The linear and interaction effects of main emulsion components (whey protein isolate (WPI, 0.4-1.2 wt%), psyllium husk gum (PHG, 1.5-4.5 wt%) and coconut oil (CO, 5-10 wt%)) on the stability were studied. The density, turbidity and droplet size of emulsions were also characterized to interpret the stability data. A significant second-order polynomial model was established (p<0.0001). Maximum stability of 98.8% was predicted at the optimum levels of formulation variables (WPI concentration 1.20 wt%, PHG content 3.30 wt%, CO concentration 5.43 wt%). The results also demonstrated that CO and WPI concentration had greater effect on the droplet size and density values, whereas the PHG:WPI ratio had a rather greater effect on the turbidity values.

Influence of beet sugar, calcium lactate, and Staphylococcus xylosus (with nitrate reductase activity) on the chemical, microbiological, and sensorial properties of Persian uncured frankfurters.

UNLABELLED: This study investigated the effects of beet sugar (BS), calcium lactate (CL), and Staphylococcus xylosus (SX) on the general characteristics of uncured frankfurters. Minimum residual nitrite was observed in samples with a high level of BS and S. xylosus (8log(10) l0 viable cfu/g) after 2 mo. There was an increase in total aerobic counts in frankfurters after 4 wk. Samples containing higher BS and CL had no Clostridium perfringens at storage time. Histamine content was similar for all treatments except SX. No differences were observed in textural properties among the treatments. Water activity was decreased significantly in treatment CL1+BS2. The results indicated that samples treated with BS or CL had (P < 0.05) taste and sensory attributes considered appropriate by a tasting panel. PRACTICAL APPLICATIONS: Frankfurters are among the most popular meat products in many countries. Health problems (such as cancer) associated with the overconsumption of cured meat have led to searches for new, alternative methods of preservation. Hurdle technology (combinations of beet sugar, calcium lactate, and Staphylococcus xylosus in different concentrations) can be developed for frankfurter processing. Results of this research will be useful for meat manufacturers; however, any new process may affect the strategies chosen for marketing these products.

Developing an emulsion model system containing canthaxanthin biosynthesized by Dietzia natronolimnaea HS-1.

An acceptable strategy to incorporate canthaxanthin (CX) as a natural colorant into products is by means of oil-in-water emulsions. The used CX in this study was produced by bacterium Dietzia natronolimnaea HS-1 using a batch bioreactor system. A central composite rotatable design-response surface methodology (CCRD-RSM) consisting of three-factored factorial design with five levels was applied for analysis of the results to obtain the optimal formulation of emulsions. Three independent variables including fenugreek gum (FG, 0.2-0.5%, w/w), coconut oil (CO, 6-10%, w/w), and CO/CX ratio (10:1-50:1) were transformed to coded values and second-order polynomial models was developed to predict the responses (p<0.0001). The studied independent variables were the stability, viscosity and droplet size properties such as volume-weighted mean diameter (D43), specific surface area (S(v)) and polydispersity index (PDI) of emulsions. The 3-D response surface plot derived from the mathematical models was used to determine the optimal conditions. Main emulsion components under the optimum conditions ascertained presently by RSM: 50:1 CO/CX ratio, 0.49% (w/w) FG content and 6.28% (w/w) CO concentration. At this optimum point, stability, viscosity, D43, S(v) and PDI were 90.6%, 0.0118 Pas, 0.595 µm, 12.03 m²/ml and 1.380, respectively.

Development of a solid-state fermentation process for production of an alpha amylase with potentially interesting properties.

Ca-independency with potential activity and stability at low pH are among the most interesting characteristics of alpha-amylase in starch industry. In this attempt the synergetic effect of low pH on activity of crude Ca-independent alpha-amylase isolated from a native Bacillus sp. KR-8104 in solid-state fermentation (SSF) was studied using wheat bran (WB) as a substrate. The effects of different parameters including moisturizing agents, solid substrate to moisture ratio, particle size, incubation temperature and period, inoculum (v/w) and supplementation with 1% (w/w) different carbon and nitrogen sources on enzyme production were investigated. Maximum enzyme production of 140U/g dry fermented substrate was obtained from wheat bran moistened with tap water at a ratio of 1:1.5 and supplemented with 1% (w/w) NH(4)NO(3) and 1% (w/w) lactose after 48h incubation at 37 degrees C. Even though the production of alpha-amylase was lower at 40 and 45 degrees C, the viable cell count was higher. In addition response surface methodology (RSM) was applied to find optimum conditions of temperature and pH on crude amylase activity. Using central composite design (CCD) a quadratic mathematical model equation was derived for the prediction of enzyme activity. The results showed that the model was in good agreement with experimental results, with R(2)=0.90 (p<0.0001) and the low pH has a synergetic effect on enzyme activity at higher temperature.