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Dry Basis (dry + basis)
Selected AbstractsThermo-physical properties of composite bread dough with maize and cassava floursINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2010Olufunmilola Olaitan Oladunmoye Summary Composite wheat,cassava and wheat,maize flours were produced in ratio 100:0. 60:40, 50:50, 40:60 and 0:100 respectively. Thermo-physical properties of bread dough were determined. For wheat ,cassava composite bread dough, moisture content ranged between 44.02 ± 2.04 to 51.31 ± 2.99% dry basis (db), density (1035.2 ± 20.4 to 975.6 ± 12.6 kg m,3), specific heat capacity (2.51 ± 0.61 to 3.01 ± 0.42 kJ kg,1 K) and thermal conductivity (0.362 ± 0.13 to 0.473 ± 0.12 W mK,1). While wheat,maize mixture gave 44.14 ± 1.94 to 45.09 ± 1.26%(db) of moisture content, 981.4 ± 16.3,960.4 ± 22.5 kg m,3 density, 1.77 ± 0.17,2.61 ± 0.63 kJ kg,1 K specific heat capacity and 0.36 ± 0.07,0.39 ± 0.02 W mK,1 thermal conductivity. Effects of substitutions was significant on moisture content and thermal conductivity of dough while non significant influence was recorded on density and specific heat capacity at P < 0.05. [source] A mathematical model to describe the change in moisture distribution in maize starch during hydrothermal treatmentINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2009Ikbal Zarguili Summary Instantaneous Controlled Pressure Drop, ,Détente Instantanée Contrôlée' (DIC) was performed on standard maize starch at residual moisture content (,12%). Changes in moisture distribution were observed during the treatment and modelled through a phenomenological model based on gravimetric data. The model proposes an exponential variation in the moisture content with processing time at various pressures. The predicted data were found to be in good agreement with experimental data. The values of water activity coefficient (,) obtained from the model decrease, when processing pressure increases; 5.86, 3.71 and 3.36 (dry basis),1 for 1, 2 and 3 bar, respectively. The mass transfer coefficient decreases, when the pressure increases. Its value ranged from 5.89 × 10,5 m s,1 for 1 bar down to 0.92 × 10,5 m s,1 for 2 bar and 0.77 × 10,5 m s,1 for 3 bar. This coefficient is not only controlled by a simple resistance to the mass transfer, but also by gelatinisation phenomenon that progresses when temperature increases. [source] The resistance of packed beds of moth gram (Vigna aconitifolius) to airflowINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2006Prabhakar M. Nimkar Summary The resistance of packed beds of clean moth gram (Vigna aconitifolius) to airflow was studied at moisture contents varying from 5.64 to 19.42% dry basis (d.b.) and at superficial air velocities ranging between 0.0104 and 0.8321 m s,1 with bed depths of 0.2,0.6 m and bulk densities ranging from 745 to 875 kg m,3. The airflow resistance of moth gram increased with increase in airflow rate and bulk density and decreased with moisture content. Results indicated that a 13.78% increase in moisture content decreased the pressure drop by 26.58% whereas, a 7.7% increase in bulk density increased the pressure drop by 43%. The modified Shedd's equation and Hukill and Ives equation were evaluated to see if they predicted pressure drop accurately. Airflow resistance was accurately described by the modified Shedd's equation. The statistical model that related airflow rate and bulk density could fit pressure drop data reasonably well. For loose fill beds an increase in grain moisture content increased the minimum fluidization velocity value from 1.1009 to 1.2391 m s,1 whereas, for grain beds with 12.47% moisture content, the increase in bulk density decreased the minimum fluidization velocity value from 1.1152 to 1.0306 m s,1. [source] Kinetics and thermodynamics of glucoamylase inhibition by lactate during fermentable sugar production from food wasteJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2010Xiao Qiang Wang Abstract BACKGROUND: Glucoamylase hydrolysis is a key step in the bioconversion of food waste with complicated composition. This work investigated the effect of lactate on glucoamylase from Aspergillus niger UV-60, and inhibition mechanisms of glucoamylase by lactate during food waste hydrolysis. RESULTS: For 125 min hydrolysis of food waste (10%, dry basis), reducing sugars produced in the absence of lactate were 15%, 26% and 56% more than those produced in the presence of 24 g L,1 lactate at 60, 50 and 40 °C, respectively. Kinetic study showed that the type of glucoamylase inhibition by lactate was competitive, and Km (Michaelis-Menten constent), Vmax (maximum initial velocity), KI (inhibition constant) were 103.2 g L,1, 5.0 g L,1 min,1, 100.6 g L,1, respectively, for food waste hydrolysis at 60 °C and pH 4.6. Lactate also accelerated glucoamylase denaturation significantly. Activation energy of denaturation without inhibitor was 61% greater than that of denaturation with inhibitor (24 g L,1 lactate). Half-lives (t1/2) without inhibitor were 7.6, 2.7, 2.6, 1.7 and 1.2 times longer than those with inhibitor at temperature 40, 45, 50, 55 and 60 °C, respectively. CONCLUSION: These results are helpful to process optimization of saccharification and bioconversion of food waste. Copyright © 2010 Society of Chemical Industry [source] COFFEE DRYING IN A ROTARY CONDUCTION-TYPE HEATING UNITJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2004GIKURU MWITHIGA ABSTRACT Parchment coffee (Arabica) was dried from an initial moisture content of about 90% to 10% dry basis (db) in a recirculating rotary conduction type heating unit at controlled plenum temperatures of 100, 120 and 140C or controlled product temperatures of 50, 60, and 70C. the temperature of the plenum or moving beans could be maintained at specified levels with small variations during coffee drying experiments. the color and specific gravity of coffee beans exhibited minimum changes as a result of drying operations. the susceptibility of coffee beans to breakage decreased with the lowering of moisture and attained minimum values in the moisture content range of 20 to 30% db. the breakage susceptibility increased sharply with further reduction in moisture content. A drying model, which considered product temperature-time history alone under different operating conditions, estimated the change in moisture content adequately. Such a model could be used for computer-based control of the coffee drying process. [source] COATING WITH HONEY: A STUDY WITH MODEL SOLIDSJOURNAL OF FOOD PROCESS ENGINEERING, Issue 3 2002BHAVESH K. PATEL ABSTRACT Simulation studies on coating of steel balls with honey as well as the rheological measurements were carried out at different moisture contents (20.3,37.7%, dry basis), and temperatures (5,80C). The coating characteristics of honey were judged by the thickness of honey layer, and by the proposed index, dimensionless uptake. Honey possesses extremely high viscosity at low temperatures and/or at low moisture contents. The sensitivity of honey viscosity with temperature was determined by using Arrhenius equation. Enhanced values of dimensionless uptake and thickness were obtained at low temperature-low moisture combinations. Viscosity of honey for easy handling and coating is in the neighborhood of 103 mPas corresponding to a temperature of 50C. [source] MOISTURE SORPTION ISOTHERM, PROPERTIES OF SORBED WATER AND HEAT OF SORPTION OF SANDESH, AN INDIAN MILK PRODUCTJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2010J.K. SAHU ABSTRACT Moisture sorption isotherm of sandesh, one of the most popular milk products in India, was determined in terms of its moisture adsorption isotherms by gravimetrical method at 20 and 30C using various saturated salt solutions in the range of 11.2 to 97.2%. The isotherms obtained were of sigmoid shape and of the Brunauer,Emmett,Teller type. Out of three sorption models fitted to the experimental data, Caurie's model was found superior in interpreting the moisture adsorption characteristics of sandesh. The monolayer moisture content as calculated from the Caurie's model at 20 and 30C were 5.89% (dry basis [d.b.]) and 5.21% (d.b.), respectively. The values of isosteric heat of sorption as calculated from Clausius,Clapeyron equation was found to increase with decreasing moisture content at lower moisture content and approached the value of heat of vaporization of free water above 17.25% (d.b.). PRACTICAL APPLICATIONS The present paper describes basically the storage stability of sandesh. The sandesh is a heat,acid coagulated product of milk in Indian subcontinent and forms the part and parcel of social life, ceremonies and festivals. It has an excellent market potential and higher profit margin compared with other milk products like table butter, cheese and milk powder. Although Indian dairy industry has made rapid strides in the last few decades, there is no proper packaging system, developed so far, for storage of sandesh. Keeping pace with the growing consumers' demand for fresh, convenient and microbiologically free foods, design of proper packaging system is the need of the hour. The data presented in the paper will be very much essential for the researchers and research and development institutions for proper designing of packaging system for sandesh. [source] Whey Protein Solution Coating for Fat-Uptake Reduction in Deep-Fried Chicken Breast StripsJOURNAL OF FOOD SCIENCE, Issue 1 2010Ann M. Dragich ABSTRACT:, This study investigated the use of whey protein, as an additional coating, in combination with basic, well-described predust, batter, and breading ingredients, for fat-uptake reduction in fried chicken. Chicken breasts were cut into strips (1 × 5 × 10 cm) and coated with wheat flour (WF) as a predust, dipped in batter, coated with WF as a breading, then dipped in 10% denatured whey protein isolate (DWPI) aqueous solution (wet basis). A WF-batter-WF treatment with no DWPI solution dip was included as a control. Coated chicken strips were deep-fried at 160 °C for 5 min. A Soxhlet-type extraction was performed to determine the fat content of the meat fraction of fried samples, the coating fraction of fried samples, raw chicken, and raw coating ingredients. The WF-batter-WF-10% DWPI solution had significantly lower fat uptake than the WF-batter-WF control, by 30.67% (dry basis). Practical Application: This article describes applied research involving fat reduction in coated deep-fried chicken. The methods used in this article were intended to achieve maximized fat reduction while maintaining a simple procedure applicable to actual food processing lines. [source] Amino Acid and Mineral Composition of Protein and Other Components and Their Recovery Yields from Whole Antarctic Krill (Euphausia superba) Using Isoelectric Solubilization/PrecipitationJOURNAL OF FOOD SCIENCE, Issue 2 2009Y.-C. Chen ABSTRACT:, Proteins and insolubles were recovered from whole Antarctic krill via novel isoelectric solubilization/precipitation using different pH treatments. The protein recovery yield was 45% to 50% (dry basis). The recovered proteins had higher (P < 0.05) content of essential amino acids (EAAs) and non-EAAs as well as higher (P < 0.05) ratio of total EAA/total AA than whole krill. The EAAs constituted almost 50% of total AAs. The least extreme pH treatments (pHs 3 and 12) yielded highest (P < 0.05) content of EAAs. The quality of recovered proteins was high based on EAAs meeting FAO/WHO/UNU recommendations for adults and infants. The basic pH yielded proteins with the lowest (P < 0.05) amount of minerals and the highest (P < 0.05) amount of Ca, P, and Mg in the insolubles when compared to the acidic treatments. However, both basic and acidic treatments effectively removed minerals from recovered proteins without the removal of the exoskeleton before processing. Therefore, besides high-quality proteins, the insolubles may provide a mineral supplement in the animal diet. [source] Antimicrobial Effects of Lactoferrin, Lysozyme, and the Lactoperoxidase System and Edible Whey Protein Films Incorporating the Lactoperoxidase System Against Salmonella enterica and Escherichia coli O157:H7JOURNAL OF FOOD SCIENCE, Issue 7 2005Seacheol Min ABSTRACT: Lactoferrin (LF), lysozyme (LZ), the lactoperoxidase system (LPOS), and edible whey protein isolate (WPI) films incorporating LPOS were studied for inhibition of Salmonella enterica and Escherichia coli O157:H7. Antimicrobial effects of LF (5 to 40 mg/mL), LZ (1 to 20 mg/mL), and LPOS (0.5% to 5.0% [w/v] [0.03,.25 g/g, dry basis]) were examined by measuring turbidity of antimicrobial-containing media after inoculation and by examining cell inhibition by WPI films incorporating LPOS (LPOS-WPI films) on an agar recovery medium. Elastic modulus (EM), tensile strength (TS), percent elongation (%E), oxygen permeability (OP), and Hunter L, a and b of WPI films incorporating 0.03 to 0.25 g/g of LPOS were compared with those of plain WPI films without LPOS. The growth of S. enterica and E. coli O157:H7 (4 log colony-forming units [CFU]/mL) in tryptic soy broth (TSB) was not prevented by LF at ,20 and ,40 mg/mL, respectively. S. enterica and E. coli O157:H7 in TSB were not inhibited by LZ at , 6 and , 20 mg/mL, respectively. LPOS at concentrations of 2.75% (w/v) and 1.0% (w/v) reduced S. enterica and E. coli O157:H7 to below the limit of detection (1 CFU/mL) in TSB, respectively. LPOS-WPI films (0.15 g/g) completely inhibited S. enterica and E. coli O157:H7 (4 log CFU/cm2), inoculated either onto agar before placing the film disc or onto top of the film disc. Incorporation of 0.25 g/g of LPOS decreased EM, TS, and %E. The oxygen barrier property of WPI films was improved with the incorporation of LPOS at 0.15 to 0.25 g/g. [source] Thermal Kinetic Parameters of Thiamin in Wheat Flour at Temperatures Higher than 100°CJOURNAL OF FOOD SCIENCE, Issue 3 2005Maria Suparno ABSTRACT: Kinetic parameters for thiamin degradation were obtained using 2 high-temperature heating methods: (1) atmospheric pressure (AP) with moisture correction and (2) controlled pressure (CP). At AP conditions, 33.3% dry basis (db) moisture wheat flour with 0.35% (db) thiamin was heated in thin steel cells isothermally at 145,160, and 172°C. To obtain the moisture correction factor, a constant-moisture study was conducted at 80°C using 6 moisture contents (6.1% to 36.9%). At CP conditions, flour at 19%, 28.2%, and 33.3% (db) moisture in double-seamed cans was heated in a CP steam retort at 129°C. For the AP method, the corrected activation energy for 33.3% moisture content was 129.5 kJ/g-mol and reaction rate at 80°C was 3.48×10,4 min,1. Using the CP method, the activation energy and reaction rate were 121.0 kJ/g-mol and 9.69×10,5 min,1, respectively. Results obtained from 2 methods were not statistically different. These results illustrated that the correction method could be used as an alternative for researchers without access to controlled pressure equipment and transient heat transfer software. [source] Heat-moisture Treatments of Cowpea Flour and Their Effects on Phytase InactivationJOURNAL OF FOOD SCIENCE, Issue 2 2005Nicole S. Affrifah ABSTRACT: Samples of finely ground cowpea flour with moisture content adjusted to 10%, 25%, 35% (dry basis) were heated in sealed retort pouches at 70 to 95°C for periods of 2 to 32 min. Phytase showed a high thermal resistance with residual activity ranging between 50% and 95%. Thermal inactivation of cowpea phytase was adequately described by a fractional conversion model based on a 1st-order rate equation. Overall, increasing temperature and initial moisture content resulted in increased enzyme inactivation. Estimated activation energies between 70 and 95°C were 33.3, 37.9, and 43.4 kJ/mol at 10%, 25%, and 35% moisture, respectively. The kinetic models generated were successfully used to predict phytase activity in cowpea flour. [source] Hard Red Winter Wheat/Nutrim-OB Alkaline Fresh Noodles: Processing and Texture AnalysisJOURNAL OF FOOD SCIENCE, Issue 1 2005Abdellatif A. Mohamed ABSTRACT: Nutrim was added at 10%, 20%, and 30% to Hard Red Winter wheat flour to increase soluble fiber content of fresh noodles to a minimum of 0.75 g/noodle serving (one noodle serving is 42 g or 40 g db (dry basis). The effect of Nutrim on the dough characteristics and noodles quality was tackled. The presence of Nutrim increased the final water absorption and dough tolerance as measured by Farinograph whereas the dough stability was decreased. The DSC (Deferential scanning Calorimetry) data showed that Nutrim increased the onset or peak temperatures while the ,H was reduced by 25%. The resilience of Nutrim-enriched noodles was not significantly affected. The chewiness and hardness were reduced by Nutrim added at 20% and 30%, while cohesiveness was significantly increased by all 3 Nutrim levels. RVA (Rapid Visco Amylograph) profile showed higher peak viscosity in the presence of Nutrim. The 20% and 30% Nutrimlevels increased the soluble fiber of the final product from 1.13% to 1.67% and 2.47%. The yellow color of noodles became darker with higher Nutrim amounts added. The addition of Nutrim produced dough with a more compact image with less space between the starch granules as measured by scanning electron microscopy when compared with the control. The rheological testing showed that the presence of Nutrim decreased flour suspension elastic properties. [source] Chlorpyrifos Residues Before and After Cooking of Catfish FilletsJOURNAL OF FOOD SCIENCE, Issue 1 2003P. Wan ABSTRACT :In this paper, chlorpyrifos residues were compared before and after frying, smoking or baking and quantified using GC/ECD (gas chromatography/electron capture detector) and ELISA (enzyme-linked immunosorbent assay) methods. All cooking methods reduced chlorpyrifos by 8 to 52% on a dry basis or 12 to 56% on a fat basis. Frying, which reduced chlorpyrifos residue by 56% on a fat basis was shown to provide the greatest reduction when compared to baking (22%) and smoking (12%). Statistical analysis showed that results from the GC/ ECD and ELISA methods were not significantly different (p= 0.05). [source] Extraction and Application of Dietary Fiber and Cellulose from Pineapple CoresJOURNAL OF FOOD SCIENCE, Issue 4 2002T. Prakongpan Pineapple core dietary fiber (PDF) was obtained by alcoholic extraction; pineapple core cellulose (PC) was a product of alkali extraction with a bleaching process. Total dietary fiber content of PDF and PC was 99.8% and 95.2% (dry basis), respectively, and their water activity was 0.25. PC contained 91.2% cellulose with a pH value of 4.0, while that of PDF was 6.2. The fiber product with large particle size gave higher values than the product with smaller particles for pH, water and oil retention capacity, settling volume and emulsifying activity. Both had rough, pitted surfaces and presented showed good functions in cake-type doughnuts, golden layer cake and beef burgers. [source] Water Vapor Transmission Rates and Sorption Behavior of Chitosan FilmsJOURNAL OF FOOD SCIENCE, Issue 7 2000J.L. Wiles ABSTRACT: This study measured the water vapor transmission rates (WVTR) and moisture sorption of chitosan films over a range of water vapor pressures at 25 °C. Films of a constant thickness were made using chitosan with 3 levels of deacetylation. Films were tested at test relative humidity (RH) difference between RH values of 84%, 75%, 69%, 53%, 43%, 33%, 23%, 11%, and 0 at 25 °C using ASTM F1249-90 or ASTM E 96-80. The equilibrium moisture content in the films ranged from 3.7% to 31.8% (dry basis) corresponding to 11% to 84% RH. WVTRs of films increased with increase in water vapor pressure. The mean WVTR ranged from 6.7 to 1146 (g/m2/d) over the range of water vapor pressure from 2.68 (11% RH) to 19.9 mmHg (84% RH). The percentage of deacetylation of chitosan films and the viscosity of the cast solution did not have an effect on the WVTR properties of chitosan films. [source] Isolation, structural features and rheological properties of water-extractable ,-glucans from different Greek barley cultivarsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2004Maria Irakli Abstract ,-Glucans were isolated from six Greek barley cultivars (Persefoni, Kos, Thessaloniki, Athinaida, Dimitra and Triptolemos) by water extraction at 47 °C, enzymatic removal of starch and protein and subsequent precipitation of the water-soluble ,-glucans with 37% (w/v) ammonium sulfate saturation. The purity of barley ,-glucans was high (>93% dry basis) with some small contamination by protein (<3.84%). The molecular size of the ,-glucan isolates was determined by high-performance size-exclusion chromatography (HPSEC); the weight-average molecular weights and the intrinsic viscosities ranged between 0.45 × 106 and 1.32 × 106 and 2.77 and 4.11 dl g,1, respectively. Structural features of barley ,-glucans were revealed by 13C NMR spectroscopy and high-performance anion-exchange chromatography (HPAEC) of the oligomers released by the hydrolytic action of lichenase. Lichenase degradation showed that ,-glucans from all barley cultivars consisted of blocks of cellotriosyl and cellotetraosyl units, accounting for 90.6,92.3% of the total oligomers released, with a molar proportion of these units between 2.31 and 2.77. Rheological measurements of aqueous solutions/dispersions of ,-glucans showed the behaviour of non-interacting polysaccharides and a transition from the typical viscoelastic response to gel-like properties after a time period that depended on the molecular size of the polysaccharide. The lowest molecular size ,-glucans from the Triptolemos cultivar showed shorter gelation times than their higher molecular weight counterparts. The effect of sugar incorporation (glucose, fructose, sucrose, xylose and ribose), at a concentration of 30% (w/v), to the ,-glucans gels (6% w/v) on compression parameters seemed to be related to the type of sugar used; the pentose sugars substantially reduced gel firming. Copyright © 2004 Society of Chemical Industry [source] Nutritive value of chicken and potato mixtures for infant and preschool children feedingJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2003Angela Sotelo Abstract Two chicken/potato protein mixtures (50:50 and 60:40) were prepared for use in formulas of high nutritive value and low cost for the diet of undernourished children and those with lactose intolerance. The proximate analysis and amino acid content of the raw materials and mixtures were determined and the chemical score (CS) was calculated. The proximate analysis and amino acid content of a commercial soybean formula were used as reference. The protein quality of the mixtures was evaluated by protein efficiency ratio (PER) and digestibility measurements. The protein content of cooked chicken and potato on a dry basis was 889 and 70 g kg,1 respectively and the carbohydrate content of potato was 762 g kg,1. Tryptophan was the limiting amino acid in chicken for infants according to the 1985 FAO pattern (CS = 76), but not for preschool children. Valine was limiting in potato for both infants and preschool children (CS = 56 and 88 respectively). Tryptophan was limiting in both 50:50 and 60:40 mixtures for infants; also the PER was higher in the 60:40 mixture and not significantly different from the control (casein), but both were different from the 50:50 mixture. Since both chicken and potato are available even for low-income people, a formula prepared in the 60:40 ratio is of potential benefit for infants or preschool children who have lactose intolerance, mainly in developing countries. Copyright © 2003 Society of Chemical Industry [source] | ||||||||||