Fat Binding Research Articles

Characterization, in vitro binding properties, and inhibitory activity on pancreatic lipase of β-glucans from different Qingke (Tibetan hulless barley) cultivars

In order to explore Qingke β-glucans as functional food ingredients for prevention of obesity, the physicochemical structures, in vitro binding properties, and inhibitory activities on pancreatic lipase of β-glucans from three different Qingke cultivars, including Ganyucang (black), Dingqing (blue), and Zangqing 320 (white), were investigated and compared. Results showed that molecular weights, particle sizes, and intrinsic viscosities of β-glucans from colored (black and blue) Qingke cultivars were much higher than those of white Qingke β-glucans, respectively. In addition, the constituent monosaccharides of β-glucans from colored Qingke cultivars were determined as arabinose, xylose, glucose, and galactose, and glucose was the dominant monosaccharide. Furthermore, colored Qingke β-glucans exerted strong fat binding, cholesterol binding, and bile-acid binding capacities, as well as inhibitory activities on pancreatic lipase, which were much higher than those of white Qingke β-glucans. Indeed, the fat binding, cholesterol binding, and bile-acid binding capacities, as well as the inhibitory activities on pancreatic lipase of Qingke β-glucans were positively associated with their molecular weights and intrinsic viscosities. Results are beneficial for better understanding of the structure-function relationship of Qingke β-glucans, and β-glucans from colored Qingke cultivars (Ganyucang and Dingqing) could be further explored as functional food ingredients for prevention of obesity.

PH levels effect on functional properties of different molecular weight eel (Monopterus sp.) protein hydrolysate

The aim of this study is to investigate the effect of pH levels on functional properties of various molecular weights of eel (Monopterus sp.) protein hydrolysate (EPH). The eel was enzymatically hydrolyzed and fractionated through membranes filter (10kDa, 5kDa and 3kDa). The foaming capacity and stability, emulsifying capacity and stability index, water holding capacity and fat binding capacity between pH 2 and 10 were determined. The 5kDa EPH was found to have the highest foaming capacity at pH 2, pH 4 and pH 6, and foaming stability and emulsifying activity index at all pH levels, except pH 8 and fat binding capacity at pH 2, as compared to 10kDa and 3kDa EPH fractions. The 10kDa EPH had the highest emulsifying stability index and water holding capacity at all pH levels. This study shows that the EPH fractions at low pH level had high foaming and oil binding capacity, while at neutral pH, the fractions had high foaming stability and water holding capacity. These properties are important in making whipped cream, mousse and meringue. In contrast, EPH fractions demonstrated strong emulsifying properties at high pH levels and show potential as an emulsifier for breads, biscuits and frozen desserts.

Sweet Chili Flour Obtainment (<em>Capsicum annuum</em>) and Physicochemical and Functional Properties Determination

The aim of the study was obtained Chili flour and their physicochemical and functional characterization. The chili powder or flour, for industrial and domestic use, facilitates its conservation and delays its deterioration, due to the reduction of its humidity. Capsicum species are fruit and vegetable products that have a good drying behaviour due to their resistance to color changes caused by temperature gradients and preserving the product quality (sensorial and nutritional characteristics). The drying kinetics of chili ( Capsicum annuum ) was established to obtain flour with drying trays and its physiochemical and functional properties were determined. The samples presented 9±0.2° Brix, 91.18% humidity and green coloration were adapted to 0, 1×2, 3×2, 3 cm samples, dried at 50, 60 and 70°C temperatures on a tray with forced air speed of 2,7m/s, continual weight. When comparing the physiochemical variables %H, aw, pH and color, a significant difference was observed for the study treatments between them (p<0.05) which did not show up on the acidity property. Regarding the functional properties, between the evaluated treatments, the WRC (water retention capacity) and the FBC (fat binding capacity), there were significant differences (p<0.05) while on EC (emulsifier capacity) values were more even. Physicochemical and functional properties of chili can be preserved by controlled drying.

Viscoelastic and Functional Properties of Cod-Bone Gelatin in the Presence of Xylitol and Stevioside.

The physical, rheological, structural and functional properties of cod bone gelatin (CBG) with various concentrations (0, 2, 4, 6, 10, and 15%) of low-calorie sweeteners [xylitol (X) and stevioside (S)] to form gels were investigated. The gel strength of CBGX increased with increased xylitol due presumably to hydrogen bonds between xylitol and gelatin, but with CBGS the highest gel strength occurred when S concentration was 4%. Viscosity of CBGS samples were higher than CBGX due to S's high molecular mass. The viscoelasticity (G′ and G′′), foaming capacity and fat binding capacity of CBGX were higher while foam stability was lower. The emulsion activity and emulsion stability of CBGX were a little lower than CBGS at the same concentration. The structure of X is linear making it easier to form a dense three-dimensional network structure, while the complex cyclic structure of S had more difficulty forming a network structure with cod bone gelatin. Therefore, X may be a better choice for sweetening gelatin gels.

Impact of inclusion of flaxseed oil (pre-emulsified or encapsulated) on the physical characteristics of chicken sausages

Functional meat products containing elevated omega-3 (n-3) fatty acids, such as α-linolenic acid (ALA), may be formulated by replacing animal fat with flaxseed oil, but the addition of flaxseed oil to meat products can adversely affect sensory properties, particularly textural properties. The objective of this study was to investigate how different methods of flaxseed oil incorporation into chicken sausages affected their physical characteristics, as assessed by proximate composition, water holding capacity, water and fat binding capacity, cook loss, texture profile analysis (TPA), rheological analysis and nuclear magnetic resonance relaxometry (NMR). Sausages were formulated to contain enough ALA to meet the European Food Safety Authority requirements for nutrient and health claims (0.6 g per 100 g and 100 kcal) and compared with a non-oil containing control (C). Flaxseed oil, as a source of ALA, was incorporated in the following forms: direct addition (O); pre-emulsified (E); encapsulated and freeze-dried (F); encapsulated with cross-linker genipin and freeze-dried (G); encapsulated and spray-dried (S). When compared to the other formulations, the F and G formulations had lower values for storage and loss modulus and for all TPA measurements (p ≤ 0.05). G and S formulations had lower values (p ≤ 0.05) for cook loss than the other formulations. NMR showed that water populations in the G and S formulations behaved differently during heating compared to the other formulations. In summary, the physical characteristics of sausages were affected by flaxseed oil incorporation method, with encapsulation methods having the greatest impact compared to direct or pre-emulsified oil addition.

Extraction and characterization of chitosan from prawn shell waste and its conjugation with cutinase for enhanced thermo-stability

The present article describes extraction of chitosan from prawn shells waste and its application in thermal stabilization of Fusarium sp. ICT SAC1 cutinase by non-covalent and covalent conjugation. Extracted chitosan represented 78.40% degree of deacetylation (DDA), a molecular weight of 173 kDa and was soluble in 1% acetic acid with 2.8 ± 0.15% insoluble matter. The structural (FTIR, NMR and XRD) and thermal characterization (DSC and TGA) indicated unique properties for chitosan. Plausible chitosan structure was also deduced. The water and fat binding capacities were 923% and 598.05% while 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and 1,1-diphenyl-2-picrylhydrzyl radicals scavenging activity was 60.62 and 11.83 μM Trolox-Equivalent/ml. The Km and Vmax values of free cutinase were 0.82 mM and 20.64 mM/min which increased by 14.63 and 17.07%; and 27.18 and 43.94% after non-covalent and covalent conjugation, respectively. A marginal increment in thermal inactivation constants and energy (kd, t1/2, D and Ed value) were also noticed for cutinase-chitosan conjugates. The enthalpy, free energy and entropy values increased marginally in covalent conjugate vis-à-vis non-covalent conjugated and free cutinase. A reduction in α-helix, random coils and β-sheets content was noted after conjugation.

Pullulanase treatments to increase resistant starch content of black chickpea (Cicer arietinum L.) starch and the effects on starch properties

This study aimed to increase resistant starch (RS) content of black chickpeas (Cicer arietinum L.) by using pullulanase enzyme. Physicochemical and functional properties of enzyme treated starch (NE) was compared with that of enzyme-treated and gelatinized starch (GE) and the retrograded control starch (RC). RS contents for native black chickpea starch (NS) and black chickpea flour (NF) were measured as 15.2% and 5.0%, respectively. While for NE and GE, were found as 16.4% and 12.3%, respectively. Treatments made on the NS, increased the amount of RDS and reduced the amount of SDS significantly (p < .05). When the effect of enzyme application-autoclaving and retrogradation were compared, 41.3% increase in RS content was measured. In this study; RS3 production from black chickpea starch by a pullulanase enzyme was successfully performed. Enzymatic applications also improved the functional properties such as water absorption capacity, water solubility index value, fat binding capacity and emulsifying capacity. This enzyme treated black chickpea starch samples, being functionally improved, will possibly help to produce different products with desired quality parameters. Therefore, instead of native starch, pullulanase treated black chickpea starch may be used as a functional ingredient for increasing the amount of RS in food formulations.

ИСПОЛЬЗОВАНИЕ ПШЕНИЧНОЙ КЛЕТЧАТКИ В ТЕХНОЛОГИИ МЯСНЫХ РУБЛЕНЫХ ПОЛУФАБРИКАТОВ

The problem of deficiency of food fiber in a diet is the basic one. In order to provide the population with balanced and high-grade food products it is necessary to use cultures, which have biological activity and high nutritional value, along with traditional raw materials. That is why we suggest adding wheat fiber to the production of comminuted meat products (patties). “Vitazel” wheat fiber is a plant fiber produced from the vegetative part of the wheat ear. In addition to the positive effect on the human body it has a number of technological advantages, namely it increases the viscosity, fat and moisture binding ability of minced meat, improves the molding process, preserves juiciness, reduces the percentage of loss during heat treatment, eliminates the accumulation of fat on the walls of process equipment. By the analysis of researchers it is stated that the optimal dose of input into the composition of meat products is the dosage of wheat fiber of 2.0 % at a degree of hydration of 1:7. By the results of analysis it has been revealed that introduction of fiber has a positive effect on technological indicators. The yield of the product increases by 1.6 %, the moisture and fat retention capacity-by 2 % and 0.3 % respectively, the moisture content of the enriched product has been increased by 2.1 %. As a culinary treatment of the produced product we propose to use steam cooking, since this type of thermal treatment helps to minimize the loss of nutrients, vitamins, and dietary minerals. When steam cooking the mass fraction of moisture in patties with Vitazel” wheat fiber is more by 8.39 %, and the water retaining capacity has been increased by 1.14 %. Thus the introduction of Vitazel” wheat fiber in the recipe of the product contributes to the stability of polydisperse stuff system, positively affects the organoleptic characteristics, functional and technological properties of minced meat.

Preparation and characterization of physicochemical properties of golden apple snail (Pomacea canaliculata) protein hydrolysate as affected by different proteases

Abstract This study aims to prepare and characterize the physicochemical properties of golden apple snail (Pomacea canaliculata) (GAS) hydrolysate as affected by alcalase and papain commercial proteases. Characterizations of yield, degree of hydrolysis (DH), protein concentration, pH value, solubility, emulsifying and foaming properties, water holding capacity, fat binding capacity, and the structural properties of golden apple snail hydrolysate were measured. GAS hydrolysate prepared using alcalase (GASHA) showed higher yields (12.61%) and DH (88.18%) than GAS hydrolysate prepared using papain (GASHP) which showed lower yields (10.45%) and DH (72.96%). The pH value of the GASHA (pH 9.31) was significantly higher (p 0.05) between GASHA and GASHP in terms of protein concentration, foaming capacity, water holding capacity, or fat binding capacity. Examination of structural properties showed that GAHSA had higher intensity of amide II (1559.85 cm−1), while GASHP showed higher intensity of amide I (1654.26 cm−1) and III (1411.35 cm−1). Hence, the study has shown that varying the type of enzyme used in the hydrolysis of GAS significantly affects the physicochemical properties of the hydrolysate produced.

Application of gamma radiation and physicochemical treatment to improve the bioactive properties of chitosan extracted from shrimp shell

Abstract The aim of this study is to exploit a suitable chitosan extraction method from the chitin of indigenous shrimp shells by employing different physicochemical treatments and to improve different bioactive properties of this extracted chitosan (CS) by applying gamma radiation. Chitin was prepared from shrimp shell by pretreatment (deproteination, demineralization and oxidation). Chitosan was extracted from chitin by eight different methods varying different physicochemical parameters (reagent concentration, temperature and time) and assessed with respect to the degree of deacetylation, requirement of time and reagents. The method where chitin was repeatedly treated with 121°C for 30 min with 20 M NaOH, produced the highest degree of deacetylation (DD) value (92%) as measured by potentiometric titration, with the least consumption of time and chemicals, and thus, selected as the best suitable extraction method. For further quality improvement, chitosan with highest DD value was irradiated with different doses (i.e., 5, 10, 15, 20 and 50 kGy) of gamma radiation from cobalt-60 gamma irradiator. As the radiation dose was increased, the molecular weight of the wet irradiated chitosan, as measured by the viscosimetric method, decreased from 1.16 × 105 to 1.786 × 103, 1.518 × 103, 1.134 × 103, 1.046 × 103 and 8.23 × 102 dalton, respectively. The radiation treatment of chitosan samples increased the antimicrobial activity significantly in concentration dependent manner on both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria, as determined by the well-diffusion method. Four to five percent wet chitosan treated with a radiation dose range of 5.0–10.0 kGy rendered the highest antimicrobial activity with least energy and time consumption. Solubility, water binding capacity (WBC) and fat binding capacity (FBC) also improved due to irradiation of chitosan.

Determinants of broiler chicken meat quality and factors affecting them: a review.

Broiler production at mass level has already been achieved and now emphasis is being laid on increasing meat quality by altering various characteristics of broiler meat. Appearance, texture, juiciness, wateriness, firmness, tenderness, odor and flavor are the most important and perceptible meat features that influence the initial and final quality judgment by consumers before and after purchasing a meat product. The quantifiable properties of meat such as water holding capacity, shear force, drip loss, cook loss, pH, shelf life, collagen content, protein solubility, cohesiveness, and fat binding capacity are indispensable for processors involved in the manufacture of value added meat products. Nutrition of birds has a significant impact on poultry meat quality and safety. It is well known that dietary fatty acid profiles are reflected in tissue fatty acid. Management of poultry meat production is reflected mostly on consumption features (juiciness, tenderness, flavour) of meat. After slaughter, biochemical changes, causing the conversion of muscle to meat, determine final meat quality. Postmortem carcass temperature has profound effect on rigor mortis and the physicochemical changes observed in PSE muscles are attributed to postmortem glycolysis, temperature, and pH. Primary processing and further processing have become a matter of concern with respect to nutritional quality of broiler meat. Genetic variation among birds could contribute to large differences in the rate of rigor mortis completion and meat quality. Heritability estimates for meat quality traits in broilers are amazingly high (0.35-0.81), making genetic selection a best tool for improvement of broiler meat quality.

Technological characteristics of cold-set gelled double emulsion enriched with n-3 fatty acids: Effect of hydroxytyrosol addition and chilling storage

A study was carried out to analyse the technological characteristics and microbiological content of gelled double emulsions (GDE) formulated with perilla oil (as lipid phase and source of n-3 fatty acids) combined or not with hydroxytyrosol (Hyt) (in the inner aqueous phase) over 30days storage at 4°C. Both the control sample without Hyt (GDE-C) and the sample containing Hyt (GDE-Hyt) had an appropriate whitish solid-like structure with rheological (elastic and viscous moduli, and phase angle) and textural (hardness and chewiness) properties of strong gels. In comparison with GDE-C, the presence of Hyt promoted the formation of weaker gels, as evidenced by lower hardness and chewiness values and elastic modulus. Overall, GDEs presented excellent water and fat binding properties irrespective of the formulation and storage time. Changes in hydroperoxides and TBARs contents over storage indicated that GDEs were little prone to oxidation after 30days. Nevertheless, Hyt increased GDE antioxidant capacity by up to 12 times after preparation, although this declined with storage. Most of the antimicrobial activity of Hyt was observed during the first two weeks of storage.

Fat binding capacity and modulation of the gut microbiota both determine the effect of wheat bran fractions on adiposity

The aim of this study was to determine the impact of different wheat bran fractions on the gut microbiota and fat binding capacity to explain their differential effects on metabolic and inflammatory disorders induced by a western diet (WD) in mice. Wheat bran derived arabinoxylan oligosaccharides (AXOS), a crude fraction of wheat bran (WB), or the same wheat bran with reduced particle size (WBs) were added to the WD of mice for 8 weeks. AXOS shifted the gut microbiota composition, blunted Clostridium and Turicibacter genera and strongly promoted Bifidobacterium and Butyricicoccus genera, independently of changes in gut antimicrobial peptide expression. AXOS was the most efficient to reduce adiposity. Only WB fraction promoted fat excretion and differed from the other fractions by the capacity to increase the Akkermansia genus and to counteract gut interleukin 1 beta (IL1β) overexpression. Strikingly, WBs promoted steatosis and adipose tissue inflammation, despite its ability -like WB- to increase bacterial diversity. In conclusion, wheat bran fractions differently affect metabolic and inflammatory disorders associated with WD feeding, depending on their particle size, their fat binding capacity and their influence on the gut microbiota. Those results might be useful to take into account in nutritional advices to control obesity.

Structural, rheological, antioxidant, and functional properties of β–glucan extracted from edible mushrooms Agaricus bisporus, Pleurotus ostreatus and Coprinus attrimentarius

β-glucan was extracted from three edible mushroom varieties namely Agaricus bisporus, Pleurotus ostreatus and Coprinus attrimentarius using hot water extraction method. The extracted β-glucan was studied to investigate its structural, rheological, antioxidant and functional properties. The ATR-FTIR was used to elicit the structural conformations of the three β-glucan and SEM was used to study the surface topography. The rheological properties showed that with the increase in the concentration of β-glucan, the elastic behavior increased. The antioxidant activities were determined using different assays like DPPH (2, 2-diphenyl-1-picryl-hydrazyl), reducing power, metal chelating ability and ABTS (2,2-Azino-bis, 3-ethylbenzothiazoline-6- sulfonic acid) and all these activities varied significantly (p≤0.05) among all the β-glucan, however the β-glucan from Coprinus attrimentarius showed the highest values for all antioxidant activities. As far as the functional properties were concerned, Coprinus β-glucan also showed the highest swelling power, fat binding, emulsifying properties, bile acid binding capacity and viscosity, however foaming properties were the highest in Pleurotus β-glucan.

Effects of operative conditions on products obtained of starch-oil mixtures by single-screw extrusion.

d. The aim of the study was to evaluate the fat binding and physicochemical properties of the products under conditions of potato starch extrusion containing rapeseed or linseed oil and rapeseed oil with glycerol. The study dealt with the extrudates of potato starch produced with the addition of rape seed or linseed oil and rapeseed oil and glycerol at 22% humidity. The extrudates were obtained at two screw speeds: 80 rpm and 100 rpm. Extrudates containing rapeseed oil and glycerol (R6G) were obtained at a temperature distribution of 115/130/150&deg;C, while those with the participation of rapeseed oil and linseed oil were obtained at 120/135/128&deg;C. Water solubility index (WSI), water absorption index (WAI), specific surface area (SBET) and quantity of fat permanently bound were determined for the products obtained. When oils were added, the solubility of extrudates decreased as compared to the control samples (starch without oil; S). Rapeseed oil added to the starch mixture at the levels of 3 g and 6 g in had no sig- nificant effect on the solubility of the product and amounted to: 80.3&ndash;82.6% and 78&ndash;79.6%. The largest decrease in solubility (WSI, 55.4&ndash;57.1%) was demonstrated for samples with 6% addition of rapeseed oil and 10 g glycerol. For these samples (R6G), a significant increase in the index WAI (376&ndash;397%) was recorded. Extrudates obtained with the addition of 3 g of rapeseed oil absorbed slightly more water than those with 6 g of oil added. The specific surface area (SBET 230&ndash;256 m2/g) determined from the water vapor adsorption isotherm indicates no statistically significant difference at &alpha; = 0.05 for products with rapeseed oil, linseed oil, and controls. A significant increase in the specific surface area (SBET 284&ndash;347 m2/g) was observed for samples with 6g rapeseed oil and 10 g glycerol added. For samples with 3 g of rapeseed oil, the amount of bound fat was 1.9&ndash;2.1 g/100 g of starch and for 6% the starch percentage was 2.96&ndash;3.5 g/100 g. The water solubility of starch extrudates with the addition of oils decreases with an increase&nbsp;&nbsp; in screw speed. Starch extrudates with linseed oil and rapeseed oil plus added glycerol are characterized by an increase in water-absorption capacity with respect to the control extrudates. The products obtained with the addition of rapeseed oil and glycerol exhibit a significant increase in their specific surface area. The quan- tity of fat permanently bound during extrusion depended on: the oil type, its percentage in the mixture and the screw speed. The linseed oil was the least absorbed in the starch structure, but rapeseed oil binding increased with the increase in its level in the mixture.

Food-grade double emulsions as effective fat replacers in meat systems

Double emulsions were used to not only replace 7 and 11% of animal fat in meat products, but also as a way to enhance the product colour. The coarse emulsion containing native beetroot juice as inner water phase, sunflower oil as oil phase and 0.5% whey protein isolate as outer water phase was prepared using a rotor stator system. The resulting coarse double emulsion had a typical average droplet size of 32 μm, that was refined further using a hybrid membrane premix emulsification system resulting in an average droplet size of 20 μm. Both double emulsions were exposed to heat threatment (70 °C for 30 min), and were physically stable due to the high viscosity (2.9 Pa s). Besides these emulsions had high colour retention. When added to meat systems, both double emulsions showed good water and fat binding capacity, and they reduced the hardness and improved the colour of meat systems, which are both desirable characteristics. The main conclusion of the paper is that double emulsion technology can be used to reach dual functionality in meat products; reduction of caloric load and colour retention.

Physicochemical properties and characterization of chitosan synthesized from fish scales, crab and shrimp shells

Chitosan is derived from different starting materials such as fish scales, shrimp and crab shells by the process of deacetylation of chitin, which is carried out using 40% KOH at 90°C for 6h. Prepared chitosan was characterized by Fourier transforms infrared spectroscopy, X-ray powder diffraction, Scanning electron microscope and Thermogravimetric analysis. Futher the physicochemical properties of chitosan like Fat binding capacity (FBC), water binding capacity (WBC), solubility, average molecular weight, ash content, moisture and degree of deacetylation of chitosan were also studied. Crystalline index (%) values of commercial, shrimp, crab and fish chitosan were found to be 96, 82, 88 and 84% respectively. The presence of amino group was confirmed from the FTIR spectra of chitosan synthesized. TGA results demonstrated the lower thermal stability of chitosan. Relatively smother surface and nano-fiber structures were observed from SEM analysis. The degree of deacetylation of chitosan from different sources such as shells of fish, shrimp and crab were found to be 75%, 78%, and 70% respectively. In a similar way the WBC and FBC of fish, shrimp and crab shells were found to be 492, 358 and 138% and 226, 246 and 138% respectively.

Selection of the most suitable crustacean exoskeleton waste from fish processing industry to isolate chitosan

Shell waste produced by the sea food industry is one of the most significant problems contributing for environmental and health hazards. The most frequent method employed for disposal of these waste is burning which is environmentally costly due to low burning capacity of shells. In such a scenario, conversion of shrimp shell waste to chitosan, a commercially valuable product with a myriad of uses, could serve as an effective mode of shell remediation. Chitosan was obtained from shellfish waste by deproteination, demineralization, discoloration and deacetylation processes. It was characterized using Fourier Transformed Infra-Red (FT-IR) spectroscopy. The physico-chemical parameters such as moisture content, ash content, solubility, N-content, water binding capacity (WBC), fat binding capacity (FBC) and degree of deacetylation (DD) were analysed to compare the extracted six chitosan samples from Penaeus monodon, Portunus pelagicus, Portunus sanguinolentus, Scylla serrata, Panulirus homarus and Panulirus versicolor. The ranges for percentage yield, moisture content, ash content, N-content, percentage solubility, and WBC were 14.53±0.47%-34.13±3.72%, 3.16±1.77%-7.52±1.11%, 0.65±0.23%-53.52±5.65%, 2.02±0.03% - 6.16±0.10%, 15.28±0.62% - 47.91±5.15%, and 262.94±20.88% - 600.61±58.11% respectively. FBC varied approximately from 250% to 650% in coconut oil, sunflower oil and soybean oil. Among the six chitosan samples, P. monodon was the most suitable crustacean exoskeleton waste from fish processing industry to isolate chitosan due to the fact that in the processing of shrimps for human consumption, 40 - 50 % of the total mass is discarded as waste and high quality of chitosan extracted. Therefore, there is a high possibility of extracting good quality chitosan using exoskeleton waste of Penaeus monodon.

Functional, physiological, and rheological properties of oat β-glucan oxidized with hydrogen peroxide under soft conditions

The β-glucan fiber has been used to change the consistency, water activity, and fat binding capacity (FB), promoting viscosity, gelification or emulsification, in foods. Its properties are related to their structure, which can be modified chemically, enzymatically, and physically. The objective of this study was to evaluate the effect of oxidation under soft conditions (0.05 mL 100 g−1 and 0.10 mL 100 g−1 H2O2 for 10 and 20 min) on the functional, thermal, and rheological properties of oat β-glucan. The soft oxidation of β-glucan at higher levels of oxidant increased the power of swelling and bile acids binding capacity, resulting in a higher hypocholesterolemic effect. In the same levels, the texture profile of oxidized β-glucans gels showed a reduction in hardness and lack of adhesiveness, as well as an increase in springiness and gumminess. The viscosity of β-glucan decreased after oxidation and showed pseudoplastic behavior. Practical applications β-glucan solutions can easily suffer molecular breakdown due to different processes, which may alter the effectiveness of health benefits due to their relationship with the viscosity. Among the possible modifications to which polysaccharides like β-glucan may be submitted, oxidation stands out. Studies on oxidation of β-glucan has been carried out using hydrogen peroxide as an oxidizing agent and iron ions as a catalyst, under conditions of concentration and temperature variables. However, there are no studies of oxidation of β-glucan under soft reaction conditions, with the purpose of improving physiological properties.

Odabrane analize hitozana iz dijetetskog suplementa na tržištu - razvoj modifikovanih metoda za određivanje stepena deacetilovanja

Introduction Chitosanisanunbranchedbinaryheteropolysaccaride obtained from chitin by partial alkaline deacetylation. Chitosan is biocompatible and biodegradable polymer used in pharmacy and biomedical investigations. In dietary supplements chitosan is used for weight loss and cholesterol-lowering properties. Aim The aims of chitosan's analyses of capsules were to determine: the weight variation tests for chitosan in 0.15 g chitosan/capsule, chitosan characteristics - degree of deacetylation DDA(%) via comparison of proposed modifications of FTIR-ATR spectroscopy and acid-base titration; moisture and ash content and functional characteristics - water binding capacity (WBC) as well as fat binding capacity (FBC). Method Tests were performed for dietary supplement on market TIENS (0.15 and 0.25 g pure chitosan/capsule). For DDA(%) FTIR spectra were recorded on Nicolet iS10 Thermo-Scientific USA (ATR technique) and for acid-base titration-retitration technique with indicator bromphenol blue was applied. Loss on drying determined at 105°C and 60°C (2 h) and ash at 650°C (4 h). For WBC (10.00 ml of redestilled water) and FBC (10.00 ml soybean, corn or sunflower oil) were placed in cuvetes (30 ml) and centrifuged 3,500 rpm (25 min). The weight variation tests for 0.15 g chitosan/capsule from 2 series each of 20 weights gave x=0.1498±0.0063 g (99.87% of declared mass). Applying FTIRATR spectroscopy (two equations with absorbance ratio of bands A1655/A3450 and A1320/A1420 with corresponding baselines) provided the most harmonized DDA(%) of 92.66% (baseline b for peak at 1650 cm-1) and 89.40% (baseline b6(A1320) and b9(A1420) in relation with acid-base titration 91.49%. Moisture content was x1=7.55% (105°C) and x2=7.03% (60°C) (acceptable values <10%) and ash content of 0.51% is in accordance with regulation for usage in food industry. Higher value of WBC (496.8%) in comparison to FBC (in range 332.4-352.8%) was obtained. Conclusion The characteristics of chitosan: high DDA(%), low moisture and ash contents and functional characteristics indicate the high-quality of chitin (red leg crab - declared by manufacturer) for supplement. The results obtained by proposed modifications for DDA(%) determination were in good accordance.