BACKGROUND: Numerous studies have investigated the positive effect of chitosan and nano-chitosan loaded clinoptilolite on growth performance, digestive enzyme activity, and intestinal histomorphology in different fish species. However, there are no data evaluating the potential effect of the composites on the fish stomach.OBJECTIVES: In the current study, the effects of chitosan and nano-chitosan loaded clinoptilolite on histological features and pepsin activity in the rainbow trout stomach were considered.METHODS: Chitosan and nano-chitosan loaded clinoptilolite were synthesized, and then two hundred and forty fish (~27.75 g) fish were distributed in eight groups each in three replicates. Ten days after adaptation, the fish were fed with eight diets, including control diet (CTR), clinpotilolite (T1), chitosan composites (T2, T3, T4), and nano-chitosan composites (T5, T6, T7) for 70 days. Afterward, all fish in each tank were anesthetized in clove extract (50 μl/l), and tissue samples were obtained for pepsin activity (n= 5) and histological assay (n = 5).RESULTS: The groups administrated with nanochitosan composites showed the highest pepsin activity (P˂0.05). Additionally, histological examinations exhibited a higher epithelial height, increased mucosal density, and oxynticopeptic cells hypertrophy in fish fed composites compared to the CTR group (P˂0.05). Meanwhile, nanochitosan composite administration could cause higher reaction of secreted granules to periodic acid–Schiff (PAS) staining.CONCLUSIONS: The findings demonstrated the potential application of chitosan and nano-chitosan loaded clinoptilolite composites for improvements in the histomorphology and pepsin activity of the rainbow trout stomach, resulting in higher growth performance.

BACKGROUND: Probiotics have more functional effects and less survival  under hard acidic-bile circumstances of digestive system, and foodstuff products situation has persuaded investigators to find techniques to resolve this problem. Microencapsulation as a useful method has a perceptible effect in this regard. Objectives: The aim of this study was to assess the protective role of double coated beads of calcium alginate-chitosan-eudragit S100 achieved from microencapsulation of Lactobacillus acidophilus as a predominant flora of human and animals gut. Methods: Following activation of starter culture of L.acidophilus in MRS-broth medium,  centrifuge (at aspeed of 5000 rpm for 10 minutes) was used to purify bacteria. Extrusion technique was used for Microencapsulation of probiotic bacterium. The survey of beads solidity was carried out for 12 hours and the study of survival of microencapsulated bacteria was done for 120 minutes inside hydrochloric acid, phosphate buffer and digestive powder solution.  MRS-Salicin-agar and pour plate method and incubation at 37oC for 48 h was done for cultivation. Data were analyzed by means of an independent t-test. Results: Shape and size of beads were shown by optical microscope. The consequences demonstrated that survivability of microencapsulated bacteria in the mentioned conditions, in both situation with and without mechanical tensions, is significantly more than free bacteria (p<0/05). Conclusions: Microencapsulation with calcium alginate- chitosan-eudragit S100 plays a significant role  in increasing the rate of L. acidophilus viability.

BACKGROUND: Poultry meat belongs to perishable foods and the major concern of food industries is the microbial spoilage of poultry meat. OBJECTIVES: The aim of present study was to investigate the effect of chitosan (CH) coating enriched with different concentrations of Ziziphora clinopodioides essential oil (ZEO) in comparison with control group on some of the sensory and microbial properties of chicken breast fillets during storage at refrigerated temperature for 12 days.   METHODS: Essential oil extraction was done by hydro-distillation method and its chemical composition was determined by gas chromatography with mass spectrometry (GC-MS). In the present study, chicken breast fillets separately were dipped in 2% CH solution containing ZEO at concentrations 0, 0.5 and 1% and then stored at refrigerated condition for 12 days. After that chicken fillets were studied at 7 intervals (0, 1, 3, 5, 7, 9 and 12 days) regarding microbial (Total mesophilic and Psychrotrophic bacteria, Pseudomonas spp. and Enterobacteriaceae) and sensory (color, odor and taste) examination. RESULTS: The most important compounds of the ZEO were geraniol (20.62%), carvacrol (18.17%), thymol (5.39%), α-terpineol (7.49%) and 4-terpineol (6.83%). Results of this study revealed that in the treatments coated with CH containing ZEO, total viable counts (TVC), Pseudomonas spp., lactic acid bacteria, Psychrotrophic bacteria and Enterobacteriaceae familysignificantly (P<0.05) decreased as compared to control group during the storage period. Based on the results of the present study, coating of chicken fillets with chitosan alone or chitosan containing 0.5 % concentration of ZEO showed better sensory properties. CONCLUSIONS: CH coating enriched with 0.5 % ZEO has potential to extend shelf life of chicken fillets without any unfavorable organoleptic properties.

BACKGROUND: Many herbs such as fenugreek and orange have compounds with antioxidant properties, which can increase the shelf life of foods. Considering that fish are a popular food among consumers, they are susceptible to rapid corruption. OBJECTIVES: In this study, to improve rainbow trout (Oncorhynchus mykiss) fillet shelf life at refrigerated condition, orange juice concentrate and chitosan coating enriched with Fenugreek (Trigonella foenum-graecum) essential oil was used. METHODS: In the present study, 8 treatments were evaluated for 12 days at refrigerator temperature for Chemical indicators PH value, Total volatile nitrogen (TVN), Thiobarbituric Acid (TBA), Peroxide value (PV), Free Fatty Acid (FFA), and Sensory Properties. RESULTS: According to statistical results, fish fillets coated with chitosan enriched with 2% fenugreek essential oil and immersed in orange juice concentrate were lower than other groups for all chemical indicators and had a significant difference with the control group (P<0.05). In the DPPH test, the most inhibitory effect after BHT (butylated hydroxy toluene) was orange juice with 1.39 brix and then black pepper 2%, respectively. In the RP test, the absorbance of the coated sample with chitosan containing fenugreek essential oil and orange juice concentrate with BHT did not show any significant difference (P>0.05). Sensory evaluation also showed that the chitosan-coated sample containing fenugreek essential oil and orange juice concentrate improved the sensory index during storage compared to other groups, especially the control group. CONCLUSIONS: According to the results, it can be stated that the use of orange juice concentrate, chitosan coating and fenugreek essential oil have a significant effect on reducing the oxidation process of rainbow trout fillet at refrigerator temperature.

BACKGROUND: Many drugs such as atorvastatin are known effective in reduction of serum lipids in dogs, but with a literature review, we did not find report on the field of the effect of chitosan on serum lipid in dogs. OBJECTIVES: The purpose of the present survey was comparative evaluation of the effects of chitosan and atorvastatin on serum lipid profile changes and the influence of time on treatment process in dogs. METHODS: For the management of cholesterol powder induced hyperlipidemia, twenty healthy dogs were randomly divided into four equal groups. Group A (control) included of five dogs that were fed with cholesterol powder (4 gr/kg for 10 days). Group B was similar to group A, but in addition, atorvastatin (5 mg/kg) was administered for 45 days after induced hyperlipidemia. Group C was similar to group B, but chitosan (3 gr/dog) was administered instead of atorvastatin. Group D was a combination of groups B and C, which the combination of atorvastatin and chitosan were fed to dogs with the same dose of previous groups. Blood samples were collected four times on days 0, 10, 40 and 55 after challenge, then serum triglycerides, total cholesterol, HDL-C and LDL-C levels were measured using standard commercial kits. RESULTS: Groups of atorvastatin and chitosan (B and C) and group D were more effective in lowering serum triglyceride, total cholesterol and LDL-C and increase of HDL-C, compared with group A (p<0.05). The greatest decrease was related to group D for triglyceride (105.60±17.49), total cholesterol (119.80±11.39) and LDL-C (36.40±7.57). The greatest increase was seen in group D for HDL-C (36.40±7.57) also. In comparison between two drugs and their effects on lipid profiles, atorvastatin showed a significant difference than chitosan (p<0.05). A combination of two drugs, was more effective compared with single administration of the drugs (p<0.05). CONCLUSIONS: The present survey showed that although both drugs have hypolipidemic activity in dogs, but the effect of chitosan was lower than atorvastatin, so it is not recommended to use chitosan only. Further experimentation needs to elucidate the possible mechanism of the drugs.