Effects of different degrees of deacetylation and levels of chitosan on performance, egg traits and serum biochemistry of laying hens.

The present study was conducted to evaluate whether the deacetylation degree of chitosan (low: 70% vs. high: 90%) and its dietary level (0, 200, 400, 800, 1600 mg/kg diet) would affect laying performance, faeces viscosity, egg quality, egg and serum biochemistry of layers. For the experimental feeding period of 8 weeks, 140 four weeks old Hisex Brown layers were divided into 10 treatment groups, comprising 14 birds each. The birds were housed in individual cages in a complete randomised design. Performance was assessed by recording feed intake, egg weight, daily egg production, egg quality and egg biochemistry. Serum biochemistry parameters were determined at the beginning and end of the experiment and faeces viscosity at the end of the experiment. Feed conversion ratio and faeces viscosity were deteriorated by increased level of chitosan. Lightness of egg yolk was significantly increased in animals receiving high-degree deacetylated chitosan compared to low-degree deacetylated chitosan. Yellowness of egg yolk was affected by interaction of deacetylation degree and level of chitosan. Yolk cholesterol concentration was lower in groups receiving high deacetylated chitosan by increasing chitosan level, while laying hens fed low deacetylated chitosan had a higher level of yolk cholesterol. A significant interaction between degree of deacetylation and chitosan level was determined for serum glucose and calcium concentration. Serum total antioxidant content increased with higher levels of dietary chitosan. In conclusion, dietary level or different degrees of deacetylated chitosan may reduce yolk cholesterol and improve serum antioxidant status. However, feed conversion ratio and faeces viscosity were impaired by increasing levels of chitosan supplementation, and lightness of yolk was increased by supplementation of chitosan with a high degree of deacetylation.

Preparation and Characterization of Crayfish (Astacus leptodactylus) Chitosan with Different Deacetylation Degrees.

Background: In this study, chitosan with various deacetylation degrees was extracted from crayfish (Astacus leptodactylus) shells with the purpose of examining the effect of deacetylation on the characterization of chitosan. Objectives: Recycling of wastes has become an important issue with the advancement of shellfish processing technology. Therefore, this study examined the most important and conventional characterization parameters of chitosan extracted from crayfish shells and investigated whether crayfish chitosan can be an alternative to commercial products. Material and Methods: In order to determine the characterization of the chitosan; degree of deacetylation, yield, molecular weight, apparent viscosity, water binding capacity, fat binding capacity, moisture content, ash content, color properties, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction analyses (XRD) were applied. Results: The low (LDD) and high (HDD) deacetylated crayfish chitosan characterization results in terms of yield, molecular weight, apparent viscosity, water binding capacity, fat binding capacity, moisture content, ash content were 17.50%, 424.03-334.66 kDa, 16.82-9.63 cP, 481.29-428.04%, 419.30-355.75%, 3.32-1.03%, 0.98-1.01%, respectively. As detected by two different methods, potentiometric titration and elemental analysis, the deacetylation degrees of low and high crayfish chitosan were found close to each other, which were 76.98-94.98% and 73.79-92.06%, respectively. As the deacetylation period extended, acetyl groups were removed, and the degree of the deacetylation of crayfish chitosan increased while the apparent viscosity, molecular weight, water and fat binding capacity decreased. Conclusions: The findings of the present study are important to obtain the chitosan having various physicochemical characteristics from unevaluated crayfish wastes and to use it in many different sectors, especially biotechnology, medicine, pharmaceutical, food, and agriculture.

Explanation of difenoconazole removal by chitosan with Langmuir adsorption isotherm and kinetic modeling.

In this study, the adsorption of toxic difenoconazole pesticide was investigated by using chitosan. In the first phase of the study, chitosan was extracted from deep-water pink shrimp (Parapenaeus longirostris) shells, by deacetylation of the chitin, which is separated and disposed of after meat extraction in processing facilities in Turkey. The deacetylation degree, molecular weight, viscosity, moisture, and crude-ash values of the extracted chitosan were determined. Chitosan, having a high deacetylation degree (90.21%), was used as the adsorbent. In the second phase of the study, the effects of pH, temperature, and pesticide concentration on the adsorption were investigated. The optimum pH level for pesticide adsorption was determined as 5. It was observed that the adsorption increases as the temperature increases. A rapid increase was observed within the first 5 min of the 60-minute adsorption process in difenoconazole concentrations of 5, 15, and 25 µg/L, and after 10 min, the adsorption rate was stable. The Langmuir isotherm parameters regarding the adsorption were determined as aL = 0.635, kL = 15.10, and the Qmax value was calculated as 23.77 mg/g. In the evaluation of overall study results, it was determined that the chitosan biopolymer is a suitable adsorbent for difenoconazole pesticide adsorption.