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关键词： Chitosan   Edible films   Crab-uca  

摘要： The fish industry generates waste that negatively impacts the environment. Providing solutions that minimise this impact has become an interesting challenge in the last decades. Crab residues contain chitin in their chemical composition, which upon deacetylation affords chitosan, a polymer with potential applications in films and/or edible coatings. The present work aimed at the production and characterisation of chitosan films from crab-uca (Ucides cordatus) residues. The employed methodology led to the production of chitosan with a deacetylation degree of 92%. Several films were formulated using three concentrations of chitosan (1.5%, 2.0%, and 2.5%) and glycerol (0.30%, 0.45%, and 0.60%). In general, the edible films composed of chitosan from crab-uca and glycerol presented good optical and mechanical properties, as well as satisfactory WVP (Water Vapor Permeability) and solubility values. Chitosan filmogenic solutions at different concentrations showed antimicrobial activity against all the standard bacterial strains studied. The film with 1.5% chitosan and 0.6% glycerol has better properties for food application. The produced films have great potential for the development of future biodegradable packaging materials.

关键词： Enzymatic hydrolysis   Glass transition   Sorption isotherm   Microencapsulation   Peroxide value  

摘要： In recent years, the use of plant protein in various food applications is an increasing trend in the food industry. The present study aimed to evaluate the effect of rice protein hydrolysate as an encapsulating material on lipid oxidation stability and the physico-chemical properties of linseed oil microparticles obtained through spray-drying. Rice protein isolate was hydrolyzed to an 8% degree of hydrolysis by the proteases Alcalase and Flavourzyme. Linseed oil was microencapsulated using protein hydrolysate or intact protein combined with maltodextrin. Sorption isotherms and glass transition temperature of microparticles were determined by the static gravimetric method and differential scanning calorimetry. Lipid oxidation stability of microparticles, evaluated by peroxide value, was carried out at 45 degrees C for 55 days. The sorption isotherms corresponded to the characteristics of BET II type isotherm and the GAB model was used to calculate thermodynamic properties of water adsorption. The monolayer moisture content values were between 3.76 and 4.96 g/100 g dry matter. Protein hydrolysates obtained by Alcalase and Flavourzyme did not significantly depress the glass transition temperature of microparticles (similar to 98 degrees C and 103 degrees C, respectively) and did not change the structure of microparticles. On the contrary, the Alcalase protein hydrolysate improved the protection of the microparticles against lipid oxidation in approximately 95% when compared to the intact protein. This result can be due to the higher antioxidant capacity of Alcalase protein hydrolysate (3239 mu cool TE/g protein) when compared to the intact protein (352 mu mol TE/g protein).

关键词： Jackfruit leaf   Leaf protein concentrate   Enzymatic hydrolysis   Techno-functional properties   Antioxidant capacity  

摘要： Physicochemical, techno-functional properties and antioxidant capacity of Jackfruit leaf protein concentrate (LPC). And its hydrolysates were evaluated. LPC was obtained using the isoelectric precipitation method assisted by high hydrostatic pressure. LPC and its hydrolysates with pepsin (H-Pep) and pancreatin (H-Pan) at different interval times were characterised by colour, foaming and emulsifying properties. The antioxidant capacity through in vitro tests, such as DPPH+ and ABTS(+) radical scavenging activity was also evaluated. The degree of hydrolysis (DH) for H-Pep and H-Pan ranged from 1.78 to 3.44 to 6.12-9.21%. The enzymatic hydrolysis significantly increased (p < 0.05) the L* value of all the hydrolysates concerning the LPC. However, the H-Pep presented lower Delta E (p < 0.05) regarding the H-Pan, this could be related to the high L* values presented in the samples. The solubility of the hydrolysates was significantly higher (p < 0.05) than the LPC in all the tested pH (2.0-10.0) values (except for H-Pep at pH 10.0), reaching solubility values of 19-41 and 60-98% from pH 4.0 to 10.0 for H-Pep and H-Pan, respectively. The increase of solubility was associated with high emulsifying and foaming properties compared with LPC. The best emulsifying and foaming properties were presented at 180 and 60 min of H-Pan, respectively. The antioxidant capacity revealed that the H-Pan at 120 min of proteolysis exhibited high antioxidant properties. The values for DPPH+ and ABTS(+) were 72.38% at 0.1 mg/mL and 98.20% at 0.8 mg/mL, respectively. The results suggest that type of enzyme and hydrolysis time determined the physicochemical, techno-functional properties, and antioxidant capacity of hydrolysates.

关键词： Eucommia ulmoides Oliv. seed meal proteins   Dynamic high-pressure microfluidization   Physicochemical properties   Functional characteristics  

摘要： Eucommia ulmoides Oliv. seed oil byproducts are rich in edible proteins (35.98%, dry matter) and have been scarcely investigated. Therefore, E. ulmoides seed meal proteins (ESMPs) were extracted and modified by dynamic high-pressure microfluidization (DHPM). The results showed that DHPM induced an increase in the alpha-helix to beta-sheet ratio of ESMPs, implying the enhancement of ESMPs bioavailability. The average particle size and absolute zeta potential of ESMPs were significantly (p < 0.05) reduced by 91.07% and 27.88%, respectively, with pressure rising to 160 MPa. The solubility of ESMPs via DHPM treatment was noticeably (p < 0.05) increased. DHPM treatment elevated the water holding capacity of ESMPs under acidic conditions as well as the fat absorption capability under high temperature. The foaming properties of ESMPs depended on the protein concentration and DHPM treatment. DHPM at 40, 80, and 120 MPa significantly improved (p < 0.05) the emulsifying capability of ESMPs. Therefore, DHPM treatment would be promising for modifying the functional characteristics of ESMPs.

ISBN: (纸本)9787040555622

关键词： Starch  

摘要： Mung bean starch was subjected to continuous and repeated dry heat treatments at 130 degrees C for 3-18 hr. Changes in structural, physicochemical, and digestive properties of mung bean starch during treatment were investigated. The starch retained a C-type crystalline structure after continuous and repeated dry heat treatments. The dry heat treatments decreased the molecular weight, amylose content, swelling power, and viscosity of mung bean starch depending on treatment duration/cycles. Greater solubility and enthalpy values were found for the dry heated starch than those of the native ones. Additionally, the content of slowly digestible and resistant starch slightly increased during the early time/cycles of treatment. Furthermore, the dry-heated mung bean starch showed a lower glycemic index than that of the native ones. And the continuous dry heat-treated starch had the strongest changes in amylose content, solubility, swelling power, and pasting parameters compared to the repeated ones. Practical applications Starch is an important ingredient in the food industry, and it is widely utilized as an additive in many food products such as pastas, soups, sauces, confectioneries, and bakeries. However, due to the instability of native starch under heating and acidic environment, unsatisfactory starch products are obtained, which limits the practical application of starch in the food field. Therefore, modification of native starch using physical, chemical, and biological methods is necessary to promote their application in the food industry. The results obtained in this study suggest that dry heat treatment can be successfully applied for producing modified mung bean starch with good water solubility, higher thermal stability, and low glycemic index to promote its application in the food industry. Additionally, dry heat treatment is a safe starch modification method because it is chemical-free.

关键词： Black rice   Phenolic compounds   Starch digestion   Cooking   Roasting   Frying   Enzyme inhibition   Amylose contents  

摘要： Black rice is recognized for managing diabetes in Chinese folk medicine. Therefore, the present study investigates the effect of thermal treatments and the succeeding cooking on black rice physicochemical properties, phenolic composition, total antioxidant activity (TAA), enzymes and glycation inhibition in addition to starch digestibility. Thermal decomposition of anthocyanin and cyanidin-3-glucoside was evident across all processing methods and reflected in increasing levels of protocatechuic acid, while proanthocyanidins (TPAC) were susceptible to cooking. Roasting of grains sustained total phenolics (TPC), flavonoids (TFC), TPAC, and antilipase activity. Additionally, the combined effect of frying and cooking diminished TFC, TPAC, and alpha-glucosidase inhibition. The thermally treated grains showed pronounced activity against alpha-amylase, alpha-glucosidase, and glycation, whereas their cooked counterparts reduced the estimated glycemic index (eGI), and enhanced resistant starch (RS). Processed grains chrominance, TAA, and apparent amylose content (AAC) showed a significant correlation with phenolics. These findings are demonstrating that black rice processing is favorable for the dietary management of metabolic disorders such as diabetes and hyperlipidemia.

关键词： Electric ovens  

摘要： The effects of roasting temperature and time on color, crude oil, acrylamide, total phenols, antioxidant activity, and trans fatty acid and phenolic contents in white and brown sesame seeds. Samples were roasted in a microwave oven (360, 540, 720 W;5, 10, 15 min) and an electric oven (180 degrees C, 200 degrees C, 220 degrees C;10, 20, 30 min). Phenolic and antioxidant contents changed significantly. Maximum total phenolic content and antioxidant activity values were noted for samples roasted in the electric oven at 220 degrees C for 30 min (white, 264.17 mg/100 g, 74.76%;brown, 289.79 mg/100 g, 74.32%, respectively). Dominant fatty acids did not change significantly following electric oven roasting. Roasting at 200 and 220 degrees C caused trans fatty acid formation. Elaidic and linolelaidic acid contents were 0.05%-0.36%, 0.06%-0.33% in white sesame and 0.22%-0.41%, 0.06%-0.23% in brown sesame, respectively. Acrylamide formation was not detected. Practical applications Sesame oil obtained from roasted sesame seeds, is rich in unsaturated fatty acids, has a long shelf life and a unique aroma. Roasting process successfully increase oil, antioxidants, and total phenol content of sesame seeds. After processing of sesame seeds, major phenolic compounds were altered. Roasting of sesame seeds at 220 degrees C using conventional method is more suitable than other methods. Trans fatty acids (elaidic and linolelaidic) formation was observed at high temperatures.

关键词： Calcium   Micronisation   Flowability   Triboelectric charge   Whey protein   Calcium fortification  

摘要： Calcium fortification of nutritional products remains challenging, with sedimentation of insoluble calcium salts being the most commonly encountered challenge. In this study, three calcium salts (i.e., carbonate, citrate and phosphate), with either conventional or micronised particle size distributions were studied for physicochemical, bulk-handling and electrostatic properties. The influence of these differences in particle size on colloidal and suspension stability in a whey protein solution was investigated. Micronised powders had significantly smaller mean particle diameter (D[4,3]) (5.09-15.9 mu m) than conventional versions (59-103 mu m) (p < Micronised salts also displayed greater particle interlocking and therefore displayed very cohesive flow properties. In suspension, the sedimentation rates for the micronised salts (0.52-0.75 mu m/s) were significantly lower than conventional salts (3.51-6.66 mu m/s) < 0.05). This new information provided on the modification of physical properties of calcium salts (i.e., micronisation) is essential in supporting the formulation of nutritional products fortified with insoluble calcium salts.

关键词： Accelerated ageing   Radiofrequency   Rice   Optimization   Cooking quality  

摘要： Radiofrequency (RF) heating was explored to induce accelerated ageing in rice to reduce the time of ageing. RF exposure time and moisture content of rice were set at five levels between 10 and 115 min and 9.5-18.5% respectively using central composite rotatable design. The values of different quality attributes of rice viz., volume expansion ratio (VER), water uptake (WU), gel consistency (GC), adhesiveness (ADH), cohesiveness (COH), amylose content (AC), reducing sugars (RS), free fatty acids (FFA), peak viscosity (PV), final viscosity (FV), and overall acceptability varied between 3.79 and 3.88, 269-281 g/100 g, 80-82 mm, (-) 0.35 - (-)1.12 N, 98.45-119.13, 19.22-19.95%, 0.17-0.21%, 1.9-3.4%, 290.35-349.59 RVU, 260.51-290.45 RVU, and 3-4.8 respectively. Models obtained for all the above quality parameters were highly significant (p <= 0.0006). RF treated rice differed significantly in various physico-chemical, cooking, textural and pasting properties as compared to fresh rice. WU, GC, FFA, COH, PV and FV increased significantly (p < 0.05), whereas VER, AC and ADH decreased in RF treated rice in comparison to fresh rice. OA of RF treated rice was also significantly (p < 0.05) higher than freshly harvested rice. Design expert predicted 26.25 min of RF exposure time at 16.25% moisture content of rice as optimum condition to induce accelerated ageing in rice. The inference drawn was that the radiofrequency heating can emerge as new approach to accelerate ageing in rice.