Search

Goat meat is extensively known for its interesting nutritional value and for being an important source of protein with high quality. Its food derivatives are, therefore, a good alternative to develop new products addressed to health conscious consumers. In this work, a healthier goat product, namely, a low fat fresh sausage, was produced with the objective of evaluating the effect of inclusion of chitosan on quality, stability and shelf life. Sausages containing 2% chitosan were formulated with different fat levels (5%, 12.5% and 20%, w/w) and stored at 4 °C for 15 days. Results indicated the incorporation of 2% (w/w) chitosan was technologically feasible, due to the reduction of microbial growth and lipid oxidation, as well as the enhancement of red color. Additionally, the treated samples improved all the characteristics associated with cooking, showing the ability to bind water and fat and acquiring a firmer texture compared with control samples. Additionally, the reduction of fat content is technologically feasible without negative influences on the final product.

Chitosan (Chit) was submitted to the Maillard reaction (MR) by co-heating a solution with glucose (Glc). Different reaction conditions as temperature (40, 60 and 80 °C), Glc concentration (0.5%, 1%, and 2%, w/v), and reaction time (72, 52 and 24h) were evaluated. Assessment of the reaction extent was monitored by measuring changes in UV absorbance, browning and fluorescence. Under the best conditions, 2% (w/v) of Chit, 2% (w/v) of Glc at 60°C and 32 h of reaction time, a chitosan-glucose (Chit-Glc) derivative was purified and submitted to structural characterization to confirm its formation. Analysis of its molecular weight (MW) and the degree of substitution (DS) was carried out by HPLC-Size Exclusion Chromatography (SEC) and a colloid titration method, respectively. FT-IR and (1)H NMR were also used to analyze the functional groups and evaluate the introduction of Glc into the Chit molecule. According to our objectives, the results obtained in this work allowed to better understand the key parameters influencing the MR with Chit as well as to confirm the successful introduction of Glc into the Chit molecule obtaining a Chit-Glc derivative with a DS of 64.76 ± 4.40% and a MW of 210.37 kDa., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A low fat fresh pork sausage based on chitosan was developed with the objective of obtaining a new functional meat product with improved properties and health claims promoting cholesterol reduction. Sausages were formulated with chitosan (2%, w/w) and different fat levels (5%, 12.5% and 20%, w/w). The results indicated that incorporation of 2% chitosan into produced pork sausages with health claims of reduction of cholesterol is technologically feasible. In addition, the chitosan reduced the microbial growth, revealing interesting fat and water absorption capacities, reduced lipid oxidation, provided greater stability in terms of colorimetric parameters and promoted positive firmer texture and gumminess. The reduction of fat content to levels of 5% was positively achieved with the incorporation of chitosan. Sensorial analysis showed that panelists did not detect any significant difference in taste and any unfavorable effect on the sausage appearance as a consequence of chitosan addition and variation of fat.

Copyright of Revista do Instituto de Laticínios Cândido Tostes is the property of Revista do Instituto de Laticinios Candido Tostes and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chitosan-impregnated gutta-percha points (ChitGPP) were tested for their ability to inhibit the growth of microorganisms usually involved in root canal infections. Their mechanical properties were also studied and compared with the commonly used commercial points in endodontics. ChitGPP were more efficient in reducing the microbial load than those without chitosan. ChitGPP also possess better tensile and elastic properties than commercial ones. After six months of storage, ChitGPP's were still able to reduce the bacterial load by 1 log, suggesting that impregnation of gutta-percha points with chitosan could be a good alternative to obtain gutta-percha points with improved antimicrobial properties. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have been studied as an alternative for treatment of microbial infections and leishmaniasis, without promoting induction of microbial or parasite resistance. In this study, chitosan-based silver nanoparticles were synthesized from silver nitrate (AgNO3), sodium borohydride as a reducing agent, and the biopolymer chitosan as a capping agent. The chitosan-based silver nanoparticles were characterized by ultraviolet–visible, Fourier transform infrared, dynamic light scattering, zeta potential, atomic force microscopy, and transmission electron microscope. The antibacterial assay was performed by determination of the minimum inhibitory concentration. The antileishmanial and the cytotoxic effects induced by AgNO3, chitosan, and chitosan-based silver nanoparticles were analyzed by resazurin and MTT colorimetric assays, respectively. AgNO3, chitosan, and chitosan-based silver nanoparticles induced a marked activity against all bacterial strains and promastigote forms of Leishmania amazonensis at minimum inhibitory concentrations ranging from 1.69 to 3.38 µg Ag/mL. Interestingly, the chitosan-based silver nanoparticles presented less cytotoxicity than the AgNO3 alone and were more active against L. amazonensis than solely chitosan. Furthermore, the cytotoxic concentrations (CC50) of both chitosan and chitosan-based silver nanoparticles against macrophages were significantly higher than the IC50 against promastigotes. Thus, the chitosan-based silver nanoparticles represent a promising alternative for the treatment of microbial infections and leishmaniasis. [ABSTRACT FROM AUTHOR]

Abstract: Low molecular weight chitosan (LMWC) and chitooligosaccharide (COS) derivatives were obtained by the introduction of lactobionic acid (LA) through amide formation, obtaining different complexes COS-LA and LMWC-LA (1–5), with a degree of substitution (DS) between 3 and 16%. The synthesis of these derivatives was monitored by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), High-Performance Liquid Chromatography-Size Exclusion Chromatography (HPLC-SEC) and proton Nuclear Magnetic Resonance (1H NMR) analyses. Different functional properties, solubility, water binding capacity (WBC) and fat binding capacity (FBC), as well as the antioxidant activity (DPPH radical scavenging activity) of these derivatives were evaluated. Solubility, WBC and FBC increased in all of the chitosan derivatives respect to those of the native LMWC or COS. The most substituted derivative (LMWC-LA1, DS 15%) presented the highest value of solubility (14.4 mg/mL) while the highest levels of WBC and FBC were obtained for the derivative with a DS of 3% (LMWC-LA5; 4730% and 7100%, respectively). COS and COS-LA presented the best DPPH scavenging abilities, as shown by their low values of EC50 (1.29 and 3.45 mg/mL, respectively). An inverse relationship between the DS of chitosan derivatives and antioxidant activity was observed. LMWC-LA5 (3% DS) was the derivative with the highest DPPH activity, being higher than LMWC in all the concentrations assayed (10.2–14.3% and 6.9–13.7%, respectively). Due to their enhanced functional properties, these chitosan derivatives could be considered as very promising for their future use as additives in the food industry (i.e. to bind fat and cholesterol or avoid hardening of foods). [Copyright &y& Elsevier]

Abstract: The effect of drying methods on chitosan reactivity towards Maillard reaction during storage of dried chitosan–lactose systems was investigated. Two different structural forms of chitosan, scaffold and microspheres, were prepared. Then they were dried by lyophilization or using supercritical fluid technology (SF-CO2) and stored with lactose under controlled temperature conditions (60 °C) and water activity (aw  = 0.65). The drying method produced slight modifications on the chitosan structure especially in samples submitted to SF-CO2 treatment. Differences were more evident in the reactivity of chitosan–lactose systems during storage. Maillard reaction development was assessed by quantification of a new compound which originated from the acid hydrolysis of Amadori compounds (NFMD) resulting from chitosan–lactose interactions, and not detected in the acid hydrolysates of freshly prepared chitosan-lactose systems. Maillard reaction was influenced by different factors such as the manner of lactose addition, structure of chitosan (microspheres and scaffolds) and drying method. Lyophilized chitosan in the form of microspheres with lactose, presented the highest values of NFMD (428.45 mg/100 g of sample). The determination of this compound could be used as an index of the progress of Maillard reaction. [Copyright &y& Elsevier]