Jamming Process Research Articles

Production of Dietetic Jam of Umbu-Caja (<i>Spondias</i> sp.): Physical, Physicochemical and Sensorial Evaluations

The umbucajazeira is specie native to the Brazilian Northeast semiarid areas, which is economically explored based on the fruit. The fruit has a high agroindustrial potential, mainly for jam production. The aim of this study was to evaluate through sensorial analysis, two formulations of umbu-caja jams: a dietetic one with xylitol, used as an option for substitution of the sugars, and a conventional one. The proportion of 50:50:0.5 (pulp/sugar/pectin or pulp/xylitol/pectin) was used for jam processing. The mixture was concentrated up to reach 65°Brix. The jams were evaluated by 50 non-trained tasters, through a hedonic scale of nine points, whereas the following attributes were used: appearance, color, flavor, aroma and texture. The results of the physical and physicochemical analysis showed that the characteristics of jams prepared with sucrose are close to the ones made with xylitol, except for the total sugars and the energetic value. The jams had pH values ranging between 2.37 and 2.92; titratable acidity varying between 0.56 and 0.78 g citric acid/100 g pulp; soluble solids ranging between 60.92°and 65.08°Brix, respectively. A tendency for yellow color was noticed by the color analysis. Jam diet had the highest scores for appearance (7.4 - 7.7). No significant differences (p > 0.05) were obtained to flavor and texture. The fruit of the umbucajazeira showed to be adequate for jam manufature since they had good sensorial acceptance. The use of xylitol was satisfactory for obtaining a product with jam characteristics similar to the conventional jam, but with lower energetic value.

구연산 및 효소 불활성화 처리가 오디잼의 C3G 안정성과 항산화능에 미치는 영향

식품의 색은 관능적 품질을 결정하는 일차적인 품질요소로서 소비자의 기호성에 직접적인 영향을 미친다. 최근 식품에 사용되고 있는 인공색소의 안전성 문제가 제기되면서 식품 내 천연색소의 사용이 증가되고 있으며 항산화 기능을 비롯한 다양한 생리적 기능성이 알려짐에 따라 천연색소의 중요성이 더욱 강조되고 있다. 이러한 점에서 뽕나무 오디는 새로운 천연색소원 및 기능성 소재로서 유망시 되고 있다. 그러나 오디잼을 가공하는 과정에서 고온가열에 의해 기능성 물질인 C3G 색소의 파괴가 심하므로 C3G 색소를 안정화시킬 수 있는 가공 방법이 필요하다. 따라서 이를 해결하고자 하였다. 그 결과를 요약하면 다음과 같다. 1. 냉동된 오디는 전자렌지를 이용하여 3분간 열처리하여 색소의 안정성에 관여하는 효소를 불활성화 시킨 후 첨가 당은 올리고당이나 자일리톨보다는 설탕을 선택하는 것이 바람직하며, 구연산 0.2 % 첨가하는 것이 오디잼의 맛 뿐만 아니라 색소 함량을 향상시켰다. 특히 올리고당이나 자일리톨을 이용하여 오디잼을 제조한 경우 색소 안정성에 대한 구연산 첨가 효과가 큰 것으로 나타났다. 2. 구연산을 첨가하여 오디잼을 제조한 경우 설탕 첨가구의 항산화능 값이 가장 높았으나 항산화능에 미치는 영향은 크지 않았다. 반면, 올리고당과 자일리톨을 첨가한 경우와 열처리한 오디잼의 경우 항산화능을 향상시키는 효과가 설탕 첨가구에 비해 높은 것으로 나타났다. 따라서 올리고당이나 자일리톨을 이용하여 오디잼을 제조하고자 할 경우 반드시 구연산을 첨가하여 제조하는 것이 바람직한 것으로 판단되었다. We have developed processing methods improved cyanidin-3-glucoside(C3G) stability in mulberry fruit's jam. In the processing of mulberry jam, 3 minutes blanching using microwave inhibited the C3G destruction by maintaining the antioxidant capacity and inactivation of enzymes related to pigment's stability. Also citric acid increased C3G stability in the mulberry fruit's jam. As the adding sugar, sucrose was considered the more desirable sugar than oligosaccharide or xylitol. It showed high C3G content and antioxidant capacity compared to the two treatment groups. In conclusion, when processing mulberry fruit's jam, the addition of citric acid and the enzyme's inactivation treatment were considered effective treatment for the C3G stability and antioxidant ability.

Jamming of particles in a two-dimensional fluid-driven flow

The jamming of particles under flow is of critical importance in a broad range of natural and industrial settings, such as the jamming of ice in rivers, or the plugging of suspended solids in pipeline transport. Relatively few studies have been carried out on jamming of suspended particles under flow, in comparison to the many studies on jamming in gravity-driven flows that have revealed various features of the jamming process. Fluid-driven particle flows differ in several aspects from gravity-driven flows, particularly in being compatible with a range of particle concentrations and velocities. Additionally, there are fluid-particle interactions and hydrodynamic effects. To investigate particle jamming in fluid-driven flows, we have performed both experiments and computer simulations on the flow of circular particles floating over water in an open channel with a restriction. We determined the flow-rate boundary for a dilute-to-dense flow transition, similar to that seen in gravity-driven flows. The maximum particle throughput increased for larger restriction sizes consistent with a Beverloo equation form over the entire range of particle mixtures and restriction sizes. The exponent of ~3/2 in the Beverloo equation is consistent with approximately constant acceleration of grains due to fluid drag in the immediate region of the opening. We verified that the jamming probability from the dense flow gave a geometric distribution in the number of particles escaping before a jam. The probability of jamming in both experiments and simulations was found to be dependent on the ratio of channel opening to particle size, but only weakly dependent on the fluid flow velocity. Flow entrance effects were measured and observed to affect the jamming probability, and dependence on particle friction coefficient was determined from simulation. A comprehensive model for the jamming probability integrating these observations from the different flow regimes was shown to be in good agreement for experimental data on average times before jamming.

Analyzing the jamming of parts on the shaft in assembly processes

PurposeThe purpose of this paper is to investigate the process of jamming of the hollow parts on the shaft and to derive a mathematical model for jamming in an assembly process.Design/methodology/approachThe mathematical model for jamming of parts on the shaft in an assembly process is based on the sizes, geometry, angular declination of part and shaft axes, and the frictional factor.FindingsThe equation for angular positional tolerance of coaxial parts and shafts, based on their geometry and sizes and leading to jamming, was derived.Research limitations/implicationsA mathematical model of parts jamming on the shaft is developed for assembly mechanisms. This research does not consider flexible deformations of components in assembly mechanisms, which results in the axis concentricity of part and shaft in the assembly process.Practical implicationsThe results presented in the form of angular positional tolerance for coaxial parts and shafts based on their geometry and sizes make it possible to avoid the jamming of the parts. The results allow for formulating the angular positional tolerance of the assembly mechanisms that clamp the parts.Originality/valueThe proposed method for calculating the angular positional tolerance of coaxial parts and shafts for the assembly process should allow for increasing the reliability of the assembly process in the manufacturing industry.

Effect of Jam Processing and Storage on Phytochemicals and Physiochemical Properties of Cherry at Different Temperatures

ABSTRACT This study evaluated the effect of jam processing of cherry on the phytochemicaland physiochemical properties for fresh cherry, after processing and during 15days at 25, 35, 45 and 55C. Fresh cherry had the highest contents of total pheno-lics, antioxidant activity and anthocyanins. Jam processing significantly decreasedtotal phenolics (370.20 mg gallic acid equivalent/100 g), antioxidant activity(50.72%) and anthocyanins (6.53 mg cyanidin-3-glucoside/100 g). During jamstorage, also, a significant decrease of these compounds was observed at studiedtemperatures. Color measurements of jam during storage showed an increase oflightness and yellowness and a decrease in redness in cherry only after processing.Total color differences and chroma values increased after processing from 21.36 to31.01 and from 10.67 to 14.32, respectively, and during storage for 15 days. Q 10 values of phytochemicals were between 1 and 2 and were less sensitive to tempera-ture changes as compared with most chemical and biochemical reactions.

Enhancing transport efficiency by hybrid routing strategy

Traffic is essential for many dynamical processes on real-world networks, such as internet or urban traffic systems. The transport efficiency of the traffic system can be improved by taking full advantage of the resources in the system. In this paper, we propose a hybrid routing strategy model for network traffic system, to realize the plenary utility of the whole network. The packets are delivered according to different “efficient routing strategies” (Yan G. et al., Phys. Rev. E, 73 (2006) 046108). We introduce the accumulating rate of packets, η, to measure the performance of traffic system in the congested phase, and propose the so-called equivalent generation rate of packet to analyze the jamming processes. From analytical and numerical results, we find that, for proper selection of strategies, the hybrid routing strategy system performs better than the single-strategy system in a broad region of strategy mixing ratio. The analytical solution to the jamming processes is verified by estimating the number of jammed nodes, which agrees well with the result from simulation.

Mango (Mangifera indica) and ambarella (Spondias cytherea) peel extracted pectins improve viscoelastic properties of derived jams

Food industries in developing countries are faced with the problem of inadequate supply of additives which can be met by proper utilization of local pectin sources. Mango ( Mangifera indica ) and ambarella ( Spondias cytherea ) peels are most of the time thrown into nature or used for animal feeding . The y have been reported to be a potential source of pectins which could be used to process the fruits into various products. In order to assess their feasibility to be used in jam processing, ambarella and mango ( Mango variety) peel pectins were extracted using three different extraction conditions: HCl at 85 °C/1h, water at 70 °C/1h and oxalic acid/ammonium oxalate (OAAO) at 85 °C/1h. Compare to commercial lime pectin with degree of methoxylation (DM) 70%, phase diagrams presenting sol -gel transition of purified pectins established as sucrose concentration (40 -75 %, weight/weight) versus reduced pectin concentration (0.1 -1.8 %, weight/weight) were studied at pH 3. Mango and ambarella jams were prepared with and without highly methoxylated peels pectins (0.4 %; DM 60 -75% ) and the effect of pectins on jam firmness was studied. Prepared hot jams, with 64 % of dry matter, 60 % of sucrose and/or 0.4 % of pectin, were characterized for their gelation kinetics and mechanical spectra at 20 °C . Phase diagrams showed that at pH 3, the minimal sucrose concentration used to obtain the gel is 40 % for OAAO mango pectin, 45 % for HCl mango and OAAO ambarella pectin, and 50 % for HCl ambarella and commercial pectin . Only gelation of OAAO extracted pectins was possible at low polymer (0.2 %) and standard sucrose (60 %) concentrations. Jams prepared without pectins exhibited a week gel behaviour (G’ = 500- 1000 Pa at 10 Hz) with those of ambarella being stronger than those of mango. Because of its good physicochemical characteristics, ambarella pulp was more suitable than mango pulp for jam processing. Mango and ambarella jams exhibited very strong gels (G’= 2000- 5000 Pa at 10 Hz ) behaviour while using OAAO extracted pectins ; the viscoelastic strength of the processing fruits increases 3 -6 folds . Accordingly, OAAO extracted mango and ambarella peel pectins allow to obtain jams with excellent gelling properties

Evaluation of the Nutraceutical, Physiochemical and Sensory Properties of Raisin Jam

This objective of this study was to evaluate the effect of jam processing of grape and raisin on the nutraceutical, physiochemical, and sensory properties. The results showed that fresh grape had the highest antioxidant activity, and total phenolic and anthocyanin content followed by grape jam, raisin, and raisin jam, respectively. No significant differences existed in soluble solids, pH, or firmness between grape and raisin jams. No significant differences in color parameters, ΔE, and chroma existed between grape and raisin jam. Descriptive sensory results showed minor differences in some sensory attributes between grape and raisin jams. In terms of consumer evaluation (9-point verbal hedonic scale and a 5-point just-about-right scale) the jams made from local raisins were parity with those from grape, despite small differences especially in whole raisin jam. Although raisin and other dried products are not traditionally considered as a raw material for jam processing, they have the same potential as fresh fruits.

Quality parameters assessment in kiwi jam during pasteurization. Modelling and optimization of the thermal process

This work focuses on the optimization of the pasteurization process in kiwi jams, considering the influence of the containers size on the quality parameters through experimental measurements and kinetic models. A numerical finite element model was developed with the purpose of simulating the energy transfer during the retort thermal processing of the product. The temperatures predicted by the simulations were successfully validated against experimental data (average relative differences<5%). These temperatures were incorporated into the kinetic model that described the quality variations which corresponded well with the texture and colour variations experimentally measured. As a result the validated numerical model was used to design and evaluate equivalent thermal processes which allowed determine optimal operating conditions. These results could contribute to the optimization of thermal processing of kiwi jam in order to minimize quality losses, such as texture, colour and nutritional value.

High-accuracy mapping of inundations induced by ice jams: a case study from Iceland

Hydraulic modelling is widely used for deriving flood hazard maps featuring depth of flooding and flow velocity from discharge scenarios. Due to uncertainties about flow conditions or inaccurate terrain models, flood hazards maps obtained from hydraulic modelling may be of limited relevance and accuracy. Hydraulic modelling is particularly challenging in Arctic regions, where ice jams lead to flooding in areas that would not be subjected to inundation under open-water conditions. As numerical models of ice jam processes require information that may be difficult and expensive to collect, an alternative approach based on the photo interpretation of documented historical events is presented here. Orthophotographs and a digital elevation model at high resolution are used to support the photo interpretation process. Tested in an Icelandic watershed prone to ice jam floods, reconstructions provide locally unprecedented and robust information on the extent and depth of flooding of inundations induced by ice jams.

Tracking antioxidant properties and color changes in low-sugar bilberry jam as effect of processing, storage and pectin concentration

BackgroundRecently, an increased interest in the identification of valuable possibilities for preserving the antioxidant properties of products obtained by thermal processing of fruits rich in bioactive compounds can be noticed. In this regard, an extensive analysis is necessary in terms of thermal processed products behavior in relation to various factors. The purpose of the present study was to assess the effect which processing and storage at 20°C has on the antioxidant properties and color quality of low-sugar bilberry jam with different low-methoxyl pectin (LMP) concentrations.ResultsFor all measured parameters, it should be noted that thermal processing induced significant alterations reported to the values registered for fresh fruit. Most important losses due to thermal processing were recorded for total monomeric anthocyanins (TMA) (81-84%), followed by L-ascorbic acid (L-AsAc) content (53-58%), total phenolics (TP) content (42-51%) and FRAP (ferric reducing antioxidant power) values (36-47%). Moreover, depreciation of the investigated compounds occurred during storage at 20°C. Jam storage for 7 months resulted in severe losses in TMA content in the range 58-72% from the value recorded one day after processing. This coincided with marked increases in polymeric color percent of these products after 7 months of storage. Also, bilberry jam storage for 7 months resulted in a decrease in L-AsAc content of 40-53% from the value recorded one day after processing, 41-57% in TP content and 33-46% from the value recorded one day after processing for FRAP values. By decreasing of LMP concentration in the jam recipe from 1 to 0.3% there has been an increase in losses of investigated compounds.ConclusionOverall, the results indicated that bilberry jams can also represent a good source of antioxidant compounds, although compared to the fruit, important losses seem to occur. Practical application of this work is that this kind of information will be very useful in optimizing the jam processing technology and storage conditions, in order to improve the quality of these products.

Nanogel formation of polymer solutions flowing through porous media

A gelation process was seen to occur when Boger fluids made from aqueous solutions of polyacrylamide (PAA) and NaCl flowed through porous media with certain characteristics. As these viscoelastic fluids flow through a porous medium, the pressure drop across the bed varies linearly with the flow rate, as also happens with Newtonian fluids. Above a critical flow rate, elastic effects set in and the pressure drop grows above the low-flow-rate linear regime. Increasing further the flow rate, a more dramatic increase in the slope of the pressure drop curve can be observed as a consequence of nanogel formation. In this work, we discuss the reasons for this gelation process based on our measurements using porous media of different sizes, porosity and chemical composition. Additionally, the rheological properties of the fluids were investigated for shear and extensional flows. The fluids were also tested as they flowed through different microfluidic analogues of the porous media. The results indicate that the nanogel inception occurs with the adsorption of PAA molecules on the surface of the porous media particles that contain silica on their surfaces. Subsequently, if the interparticle space is small enough a jamming process occurs leading to flow-induced gel formation.

Developing winter flow rating relationships using slope‐area hydraulics

AbstractDespite recent advances in instrumentation and modelling methods, accurate determination of river discharge under an ice cover still requires direct measurement. Published flows at hydrometric gauging stations are based on interpolation between a few measurements that are carried out during each winter. The feasibility of using slope‐area hydraulics to develop discharge‐stage rating relationships is explored at two stations, Peace River at Peace Point and Mackenzie River at Arctic Red River. Records at both gauges contain key information for understanding local ice jamming processes, which are known to control the long‐term maintenance of the aquatic ecosystems in the respective deltas. For each site, the variations of reach‐average hydraulic parameters with stage are first determined from several nearby cross‐sections. This information is then used to calculate hydraulic resistance characteristics during the ice season based on archived discharge measurement data, which also include ice cover thickness. The Peace River flow measurements indicate a well‐defined seasonal variation in hydraulic resistance, with the exception of years with large slush deposits under the solid‐ice sheet. Slush effects are negligible at the Mackenzie River gauge site, but the stage‐flow relationship is complicated by a variable water surface slope, a result of downstream control by the Beaufort Sea. This feature is most pronounced during the pre‐breakup period when flows are rising sharply and renders flow estimation uncertain. A nearby water‐level gauge would help quantify the slope and increase confidence in winter flow estimates. Copyright © 2010 in the right of Canada.

Physicochemical and Sensorial Properties of Grapefruit Jams as Affected by Processing

Jam is an effective and tasty way of preserving fruit. Jam processing procedures as well as storage conditions and duration are important factors for jam quality. Traditional jam processing involves the application of severe thermal treatments that imply undesirable changes in the product quality characteristics such as colour, texture, flavour and nutritional and functional value. In this work, osmotic dehydration (OD) and/or microwave energy (MW) was proven as adequate to obtain jam with the typical characteristics of water content, degree Brix, pH and water activity of jam obtained by conventional thermal heating. The sensory evaluation carried out to compare the product showed that samples submitted to more intense heating treatments (conventional or MW) had significantly higher scores in colour saturation, brightness, grapefruit taste and extensibility than OD or OD+MW ones. As deduced from the obtained results, OD treatment prevents grapefruit colour changes, and mild MW heating contributes to increase the consistency and decrease the extensibility of the obtained jam. In this way, OD+MW jam was preferred by assessors mainly due to its higher consistency. The sample obtained by this procedure was stable during storage.

Analyses of peg‐hole jamming in automatic assembly machines

PurposeThe purpose of this paper is to investigate theoretically the process of jamming in the peg‐hole type parts and to derive a mathematical model of jamming.Design/methodology/approachThe mathematical model of the jamming of the peg‐hole type parts in assembly process was performed and its boundary conditions, which lead to jamming, defined.FindingsThe equation of the critical angles of declination for the peg, which leads to the peg‐hole jam, was derived. The boundary condition of the angles of declination and the depth of the peg insertion into the hole were defined.Research limitations/implicationsA mathematical model is developed for rigid parts with a hole and for the peg clamped in the rigid assembly mechanisms. The research has not considered flexible deformations and stiffness of the assembly mechanisms, which result in the peg's declination in the assembly process.Practical implicationsThe results are represented in the form of the peg's critical angles of declination and critical depth of insertion into the hole, which leads to jamming of the peg‐hole type parts to be assembled. On the basis of the obtained results, it is possible to formulate the tolerances of the declination angles for the assembly mechanisms, which clamp the peg‐type parts.Originality/valueThe proposed method calculating the critical angles of the peg's declination and critical depth of the peg's insertion into the hole for assembly of the peg‐hole type parts, enables one to increase the reliability of the assembly process in the manufacturing industry.

Suitability of some Sudanese mango varieties for jam making

The aim of this work was to evaluate the physicochemical characteristics of some Sudanese mango varieties ( Abusamaka, Galb Altour and Magloba), and to study their suitability for jam processing. The storability of mango jam was also studied. The physicochemical properties of the three mango varieties were examined. The jam prepared from different mango extracted pulps were packed into glass jars and stored under room temperature (30 o C) for four months. Optical density, chemical and organoleptic tests were carried out for the prepared mango jams. In addition, the microbial load of the stored prepared jams was determined by the enumeration of total viable count, yeast and mould concentrations. It was observed that the highest level of extracted pulp was that of Malgoba (75.48%). The obtained results also revealed that Malgoba variety had higher soluble solids and total sugars (17o Brix and 11.93%) compared to the lowest soluble solid and total sugars of the variety Abusamaka (11o Brix and 10.18%), however, the highest level of the reducing sugars (3.45%) was estimated in Abusamaka variety compared to the lowest value of GulbAltour variety (2.96%). These results also revealed that mango pectin extraction yields vary from 20.20 to 7.3 mg/ g depending on the varieties and extraction conditions used. The sensory evaluation results indicated that GulbAltour variety jam was superior in colour, taste and overall acceptability, while Abusamaka variety jam was superior in flavour. The storability results showed that storage at room temperature up to 4 months, significantly affect acidity, however, all mango varieties jams were found to be free from microorganisms.

Effect of jam processing and storage on total phenolics, antioxidant activity, and anthocyanins of different fruits

Fruits have been widely recognised as an excellent source of bioactive phenolic compounds. The purpose of this study was to evaluate the effect of jam processing of strawberry, cherry, apricot, fig and orange on the total phenolics, antioxidant activity and anthocyanins during 5 months of storage at 25 °C. Fresh strawberry had the highest contents of total phenolics (8503.1 mg GAE kg(-1) ) followed by cherry, apricot, fig and orange, respectively. Jam processing decreased the total phenolics, antioxidant activity, and anthocyanins of all fruits. Total phenolics of jam during storage decreased only in apricot, fig and orange. Fresh strawberry had the highest antioxidant activity (54.88% inhibition) followed by the other fruits. Antioxidant activity did not change in strawberry during jam storage, while there are reductions in the other fruits were observed. Fresh strawberry had the highest anthocyanins (2323.8 mg cya-3-glu kg(-1) ), followed by cherry and the other fruits, respectively. Results showed only a decrease of anthocyanins and pH in apricot and fig jams during 5 months of storage. Despite the reduction of these compounds in jam processing, it is considered a good method to maintain them during 5 months of storage.

Research on Jamming Effect Evaluation Method of ISAR Using Moment Invariants

The Inverse Synthetic Aperture Radar (ISAR) is a high resolution imaging radar. Some methods used to evaluate the jamming effect of general radar are unsuitable to ISAR. Considering the principle of radar jamming and the theory of image disposal, the paper gives a new evaluation method of barrage jamming effect on ISAR, it evaluates the jamming effect through calculating the difference of two picture’s Moment Invariants, and this method can reflect distortion degree of the jammed target during the whole jamming process. The results of simulation prove the method is corrective and effective.

On modelling and simulation of a manipulator under consideration of a jammed joint

In this paper, the modelling of a jamming process of a joint during the operation of a manipulator is presented. Based on the kinematic property of a jamming process, a motion law of the jammed joint is chosen. By introducing a matrix corresponding to jammed joint, the equation of motion of the system is restructured without re-deriving. Some numerical simulations are carried out to illustrate the proposed algorithm.

Jamming in Filled Polymer Systems

AbstractAfter an introduction into the general characteristics of the jamming behavior, two filler flocculation experiments on a polycarbonate melt filled with multi‐walled carbon nanotubes and on a silica‐filled ethylene propylene diene monomer elastomer are presented. We propose that these experiments can be regarded as jamming phenomena. The experimental data are successfully modeled using the power saturation equation. Further insights into the physics of such jamming processes have been obtained with the help of X‐ray photon correlation spectroscopy experiments.