Maximum Moisture Loss Research Articles

Effect of Different Drying Techniques of Flowers and Foliages and Its Value Addition

Fresh flowers and foliages are delightful and visually striking, it can be arduous to sustain their charm and pristine appearance over an extended duration, However this obstacle can be overcome by drying the flowers and foliages, enabling them to retain their allure. The present investigation the effect of different drying techniques of flowers and foliages and its value addition was carried out at the post harvest laboratory of Department of Horticulture, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (UP) during 2022-23. The experiment was laid out in Completely Randomized Design comprising of two different methods of flower drying i.e. microwave oven drying with silica gel and microwave oven drying with sand and replicated three times containing six flowers per replication for six different flowers and foliage i.e. Rose, Gerbera, Jatropha, Dracaena, Fern and Thuja. The aim of this investigation was to evaluate the drying techniques of Rose, Gerbera, Jatropha, Thuja, Fern and Dracaena. Maximum moisture loss was obtained in (T3) Jatropha embedded in silica gel and dried in microwave oven (77.13%). Best score in sensory evaluation in terms of colour, shape and texture was found highest in (T5) Dracaena embedded in silica gel and dried in microwave oven (scores- 4.18, 4.38, 4.03). So, the best drying technique considered was microwave oven drying with silica gel as an embedding medium.

Standardization of Drying Techniques of Dahlia, Larkspur and China Aster

The present experiment was carried out to standardize drying methods for Dahlia, Larkspur and China Aster and to assess the influence of drying and storage methods on storage quality of the dried flowers. Flowers of Dahlia, Larkspur and China Aster were subjected to seven different drying methods viz., shade drying method without embedding medium (T1), with sand embedding (T2) and with silica gel embedding (T3), microwave oven drying with sand (T4) and silica gel embedding (T5), hot air oven drying at 450C with sand (T6) and silica gel embedding (T7) and stored in cardboard and plastic boxes for three months. Data were statistically analyzed in Completely Randomized Design. The results indicated that in Dahlia, maximum moisture loss (88.25 %) and maximum per cent retention of perimeter (95.28) was observed in T7. In Larkspur, maximum moisture loss (73.43 %) was observed in T1 and maximum percent retention of perimeter (89.62 %) was observed in T4. In China Aster, maximum moisture loss (89.10 %) was observed in T5 and maximum percent retention of perimeter (95.29%) was observed in T6. Time taken for drying was found minimum in silica embedded drying in microwave oven in Dahlia (0.00208 days), Larkspur (0.00139 days) and China Aster (0.00278 days) while, shade dried flowers took maximum time to dry in Dahlia (14.0 days), Larkspur (12.0 days) and in China Aster (15.0 days). Maximum quality score on visual basis of color, appearance, texture and shattering of petals in dried flowers of Dahlia (15.73) was observed in T7, in T4 for Larkspur (15.63) and in T6 for China Aster (15.51). After 90 days of storage, minimum color fading in Dahlia, Larkspur and China aster was observed in flowers stored in plastic boxes while there was no incidence of pests or diseases observed during storage.

Energy and exergy analyses of fabricated solar drying system with smooth and rough surfaces at different conditions: A case study

AbstractFor this experimental work, the solar dryer system has been fabricated. Various experiments have been performed to evaluate the performance of the fabricated dryer system. Energy and exergy concepts have been used for the assessment. And comparative analyses have also been done with smooth and rough surfaces: Grade 150 and Grade 300. This experimental work has been concluded as the maximum collector (i.e., 74°C) and cabinet temperatures (i.e., 66°C) are attained at 13:00 p.m. with Grade 300 surface. Maximum moisture loss (i.e., 35 g) and percentage moisture loss (i.e., 7.53%) are recorded at 13:00 p.m. again with a rough surface. Minimum exergy destruction rate (i.e., 0.294 W) but minimum exergy efficiency (i.e., 20.82%) are found at 17:00 p.m. with a black painted surface, which is not an acceptable condition. Maximum energy efficiency (i.e., 35.98%) and heat removal factor (i.e., 0.56) are obtained at 13:00 p.m. with a rough surface. The best performance from the fabricated solar system is received between 12:00 and 14:00 p.m. This study recommends rough surfaces and 12:00–13:00 p.m. timings for the solar drying system as the performance of the system is better in terms of energy–exergy.

Effect of temperature and concentration of osmotic solution on moisture loss and solid gain during osmotic dehydration of carrot

The effect of temperature and osmotic solution concentration on solid gain and moisture loss drying characteristics of carrot were studied. The moisture loss and solid gain increased with increase in salt and sugar concentration and temperature. The moisture loss by carrot slices increased non-linearly with increase in duration of osmosis, solution concentrations and temperature. Mass transfer was faster in initial period of osmosis than the later period. Maximum moisture loss was obtained at 60 oC for osmotically dehydrated carrot (60% sugar, 3% salt) and it ranged from 13.32% to 56.93%. Solid gain increased with duration of osmosis and did not approach the equilibrium after 3hrs of osmotic dehydration. Solid gain at 60 oC solution temperature for osmotically dehydrated carrot (60% sugar, 3% salt) ranged from 2.34% to 5.86%. 60% sugar and 3% salt concentration with 60 0C solution temperature was found as an optimum process condition for osmosis with 3 h duration.

Grain moisture dynamics in maize lines belonging to different ripeness groups during ripening

Purpose. To study the dynamics of moisture-yielding ability in maize lines belonging to different ripeness groups during different phases of development by laboratory thermostatic-weight method and field method using an AVD 6100 needle hydrometer.Materials and methods. The study was carried out in the crop rotation fields of thePlant ProductionInstitute of named after V.Ya. Yuriev of NAAS in 2017–2019. One hundred self-pollinated maize lines belonging to different ripeness groups were investigated.The water content in grain was determined by two methods: a laboratory thermostat-weight method and a field method using an AVD 6100 needle hygrometer modified to measure the water content in maize grain. The water content in grain was evaluated every ten days in two replications (on days 30, 40, 50 and 60 days after pollination).Results and discussion. The three-year study of the grain moisture dynamics showed that mid-late accessions had the highest moisture content in grain at all sampling timepoints. On day 60 of sampling, the lowest moisture content in grain was observed in mid-early lines: in 2017 – 13.9%; in 2018 - 15.0%; and in 2019 – 19.7%.Analyzing the intensity of moisture loss by grain of maize lines of different ripeness groups, we found that on days 30–40 day of sampling from mid-early lines this parameter was almost the same in the 3 years, however, on days 40–50 in2017 the moisture loss was minimal (0.6%), and in 2018, on the contrary, – maximum (1.7%). On days 50–60 in2017, on the contrary, the moisture loss intensified, and in 2018 it slowly came down to 0.1%. In 2019, there were no sharp fluctuations in the moisture loss intensity, and the values were almost at the same.Conclusions. In each ripeness group, we singled out lines with a low percentage of grain moisture, and this allows selecting maize lines with a good moisture-yielding ability. It was established that the intensity of moisture loss by grain of the maize lines differed, and in each of the three ripeness groups, lines with the maximum moisture loss per day were distinguished.To compare the results on the moisture content in grain obtained by laboratory thermostat-weight method and field method using the AVD 6100 needle hygrometer, correlation analysis was performed. It was found that the results of the laboratory thermostat-weight method and the field method using the AVD 6100 needle hygrometer completely coincided for two test years. This allows using needle hygrometers to determine the moisture content in maize grain, which greatly facilitates and speeds up work and shortens the test period.

Pyrethrum (Chrysanthemum cinerariifolium) Flowers’ Drying Conditions for Optimum Extractable Pyrethrins Content

Pyrethrum flowers of the genus Chrysanthemum cinerariifolium are grown in Kenya by small scale farmers for extraction of pyrethrins, a natural insecticide’s active ingredient. Pyrethrins are classified in two groups, Pyrethrins I and II, and are degradable when exposed to air, moisture and high temperatures. The contents and ratio of Pyrethrins I:II determine the efficacy of the insecticide. Therefore, drying of the pyrethrum flowers should be optimized in order to attain maximum extractable pyrethrins content and optimum ratio. The aim of this research was to optimize the drying temperatures, time and moisture content of pyrethrum flowers. The flowers were harvested and dried at varying temperatures of 40, 50, 60 and 70 ºC to total dryness. Another set of flowers were harvested and dried in the oven at the same temperatures for a maximum period of 18 hrs. Moisture content was determined at each temperature, at intervals of one hour. The dried flowers were then ground into fine powder and extracted using Soxhlet extraction method with hexane. The extracts were refined and analyzed by Mercury reduction and High Performance Liquid Chromatographic methods. Pyrethrum flowers were found to achieve maximum moisture loss, at varying times and temperature with 70 ºC recording the shortest time of 18 hrs. The yield of pyrethrins obtained on drying the flowers to constant weight at 40 ºC was 0.90% while drying for 18 hrs yielded 0.79%. Extractable Pyrethrins II were found to reduce by 8.6% when the drying temperature was raised from 50 to 60 ºC and by 11.3% from 60 to 70 ºC. Extractable Pyrethrins I were found to reduce by 6% when the drying temperature was raised from 50 to 60 ºC and by 5% from 60 to 70 ºC. The total pyrethrins obtained from the flowers dried at 50 ºC were found to be 1.37% at 18 hrs and 1.44% to constant weight drying. The pyrethrins I:II ratio was found to vary over the temperature range 40-70OC.The optimum temperature and time for drying pyrethrum flowers was found to be 50 ºC for 21 hrs.

Kinetic modeling of microwave osmotic dehydration of mangoes under continuous flow medium spray conditions using sucrose and maltodextrin (10-18 DE) solute mixtures

Microwave osmotic dehydration of mango (Mangifera indica) was carried out under continuous spray mode (MWODS) with four osmotic solute mixtures (sucrose (S), sucrose in combination with maltodextrin (MD) 10 dextrose equivalent (DE), 15DE, and 18DE), at two temperatures (40 °C, 60 °C) and two concentrations (40%, 60%) and four contact times (10, 20, 30, 40 min). The mass transfer kinetics were fitted to a first-order kinetic model, by way of an empirical parameter (k) representing an overall mass transfer coefficient. Azuara model was also evaluated to describe the mass transfer kinetics. The results showed that the overall mass transfer coefficients for moisture and solids contents were influenced by temperature, concentration and, more importantly, the solute composition. The highest mass transfer coefficient for moisture loss (1.56 E−2) and lowest for solids gain (8.60 E−3) observed with sucrose + maltodextrin 10DE (S + MD 10DE) combination at 60%/60 °C and 40%/40 °C, conditions, respectively. In addition, the Azuara model well fitted the experimental data for mass transfer kinetics (R2 > 0.92). The highest moisture loss (ML) along with lower solids gain (SG) was associated with the solute sucrose + maltodextrin 10DE combination. The highest ML/SG ratio of 10 and weight reduction of 55.5% were observed with S + MD 10DE at 40 °C/60%/40 min and 60 °C/60%/40 min, respectively, with S + MD 10DE solute mixture. Overall, it was possible to successfully describe the mass transfer kinetics using empirical first order and Azuara models and MWODS with S + MD 10DE facilitated the maximum moisture loss and low solids uptake, both desirable from osmotic dehydration point of view.

Osmotic Dehydration of Cassava Cubes: Kinetic Analysis and Optimization

The present work had the objective of studying the osmotic dehydration process of cassava cubes (ManihotesculentaCrantz.) in ternary solutions containing water, sucrose, and sodium chloride. The osmotic dehydration process was studied by using a 24 factorial planning with central points at different conditions of temperature (19-63°C), solute concentration (23-67% w/w), operating time (70-190 min.) and NaCl concentration (0-20% w/w). The process optimization was verified through the performance ratio of minimum solids gain, in conjunction with the maximum moisture loss and reduction of water activity of the material. From the analysis, the optimum condition for osmotic dehydration of cassava cubes was temperature52°C, concentration of the osmotic solution 56%solute,10% NaCl concentration,160 minutes of immersion time and 180 rpm . The study of osmotic dehydration kinetics in the optimized condition showed that the moisture loss reached equilibrium in 180 minutes and the solids gain in 30 minutes. The model of Azuara and contributors was fitted to experimental data of moisture lost and total solids gain, in the optimal condition and good agreement were obtained. From this comparison, the average effective diffusivity coefficients of moisture (1.99x10-8m2/s) and total solids (2.77x10-8m2/s) were estimated.

Investigation of the films based on the uronate polysaccharides by the method of differential scanning calorimetry

In this paper, the problem of studying of the films properties on the basis of uronate polysaccharides (sodium alginate and pectin low-esterified amidated), created on the principle of ionotropic gelation with the participation of calcium ions, has being considered. The purpose of the study is to determine the patterns of films formation based on the composition of the uronate polysaccharides, to determine their properties when heated and conditions of destruction or combustion. The thermophysical properties of the films in the temperature range 20–500°C were controlled by the method of differential scanning calorimetry in the dynamic mode. The temperature at which the loss of external and internal moisture is occurring have been determined. The temperatures when films are subjected to destruction have been founded. Thus, the mass loss of samples was noted in the following temperature ranges: 52–100°С and 40–100°С; the maximum moisture loss was noted at 83 and 85°C for specimens with a total concentration of uronate polysaccharides 2% and 3% respectively. Maximum external moisture losses were 6% and 9%; intra-linked moisture – 28.5 and 29% respectively. Complete disintegration of polymers occurs after 300 and 310°C for specimens with a total concentration of uronate polysaccharides 2% and 3% respectively. The investigation of the destraction temperatures of the above systems allows us to predict the principle of heat treatment of semi-finished products contained in films, created on the basis of the reaction of ionotropic gelation of polysaccharides and calcium ions.

Standardization of drying techniques for hybrid tea rose variety, Valencia

The present experiment was carried out to standardize suitable drying techniques for hybrid tea rose variety ‘Valencia”. Two types of desiccants viz., silica gel and boric acid were used as embedding materials for drying, and the flowers were dried in hot air oven with different temperature and time combinations such as 40°C for 24 hours and 48 hours, 45°C for 24 hours and 48 hours, 50°C for 24 hours and 48 hours, 55°C for 24 hours and 48 hours, 60°C for 24 hours and 48 hours. Different observations were taken such as fresh and dry weight of flowers and hence moisture loss percentage calculated, petal diameter before and after drying were taken and hence petal shrinkage was determined. Sensory evaluations such as flower colour, shape, texture and overall acceptability was also determined. Results show that maximum moisture loss percentage (86.44%) was obtained in flowers embedded with silica gel and dried at 60°C for 48 hours; largest difference between petal diameter of fresh and dry flowers, and also maximum petal shrinkage of 14.27% occurred in those embedded with silica gel and dried at 60°C for 48 hours, whereas best score in sensory evaluations in terms of flower colour, flower shape, flower texture and overall acceptability were obtained with rose flowers embedded in silica gel and drying at 50°C for 48 hours.

Studies on microwave oven drying of Gomphrena globosa L. ‘Magenta’ and ‘White’

Present investigation was carried out to standardize the medium and temperature for drying of Gomphrena globosa L. Two cultivars ‘Magenta’ (GGM) and ‘White’ (GGW) were dried in silica gel and mixture of sand and silica gel for 3, 4 and 5 min. in microwave oven with 24, 48 and 72 h setting durations. It was observed that maximum moisture loss was recorded in flowers embedded in silica gel and dried for 5 min. with 72 h setting time in cvs Magenta and White, respectively. The maximum decrease in size was recorded in flowers embedded in silica gel and kept for 5 min. with 72 h setting time in cvs Magenta and White, respectively. However, the maximum scores for quality parameters (out of a total of 20) based on colour, texture, brittleness and shape retention were obtained when flowers were embedded in silica gel and kept for 3 min. with 72 h setting time in cv. Magenta and for 3 min. and kept for 24 h. setting in cv. White.

Evaluation of different methods for drying of chrysanthemum flowers

An investigation was conducted for evaluation of different methods for drying of chrysanthemum (Dendranthema grandiflorum Tzevlev) flowers. Fully opened flowers of chrysanthemum were dried by four different methods, viz., air drying, sun drying, mechanical dehydration and low cost solar drying at different durations. Results indicate that among different methods of drying solar drying registered the maximum moisture loss (79.31%) after 15 days of drying as compared to other methods. Among different method tested, the reduction in floral diameter was highest (55.97%) in air drying as compared to other methods. Low cost solar drying obtained better score (4.60) for colour retention than other methods. Therefore solar drier after being embedded in sterilized sand was rated to be better as compared to other methods of drying.

Process standardization and storage studies of jamun-mango bar

SUMMARY : The experiment was designed to investigate the influence of addition of mango pulp at various levels in preparation of jamun-mango bar and effect of different packaging materials and storage conditions on quality. Results indicated that addition of 20 per cent mango pulp can be improved the sensory quality of jamun bar with respect to taste and texture. Efforts were also made to prepare bar using different types of sugars and no significant effect on acceptability of product by changing type of sugar. The storage study revealed that moisture content was decreased continuously with storage. Maximum moisture loss was from samples stored in butter paper and minimum in samples stored in polyethylene in PET bottles. The T.S.S. was increased slightly during storage in all the packaging materials. The total sugars were found to be decreased consistently with increase in reducing sugars. The Anthocyanin pigments remained quite stable during storage of bar. These changes were quite less in samples stored in refrigerated storage as compared to ambient temperature. However, the product can be stored without any changes up to 270 days of storage.

Measurement of Lipid Peroxidation and Phenol Contents Under Heat Stress Condition in Sugarcane Genotypes

The experiment conducted in the laboratory of Plant Breeding and Molecular Genetics, Faculty of Agriculture, Rawalakot, Pakistan. Leaves of thirteen genotypes of sugarcane used for this experiment and were treated in an oven for heat stress. The treated leaves were then used for the estimation of phenol contents and the measurement of lipid peroxidation against heat stress. Minimum moisture loosed by CPF-237 and maximum moisture loss showed by CO-1148. Maximum phenol contents were observed in S-2003-US-778 showed high results (58.78 mg GAE/100ml) and minimum were Rb-72 and CO-1148 showed the lowest values (36.17 and 37.5 mg GAE/100ml). The higher heat tolerance of genotype, CPF-237 related to higher membrane stability, and maintenance of high fv/fm ratio under heat stress and lower lipid peroxidation of membranes. Hence, the relative tolerance of a genotype to heat stress as reflected by its lower lipid peroxidation, and higher membrane stability and pigment concentration, related to the levels of activity of its antioxidant enzymes. By using morphological parameters, S-2003-US-778 was significantly different from Rb-72. Based on biochemical data, the genotypes S-2003-US-778, S-2003-US-694, CPF-237 and Co-1148 are heat tolerant genotypes and thus can be successfully planted in warmer areas to alleviate the socioeconomic status of farmers.

Classification of Sugarcane Genotypes Based on Heat Stress and Morphological Parameters

Leaves of thirteen genotypes of sugarcane were treated in the oven for heat stress. The treated leaves were used for the estimation of phenolic contents and the measurement of lipid peroxidation. Minimum moisture loss is showed by CSSG-668 and maximum moisture loss showed by NSG-45. Maximum phenolic contents were observed in HSF-240 (65.7 mg GAE/100 ml) and minimum results showed by Lho 83-153 and CP-43-33 (32.98 and 33.78 mg GAE/100 ml). Lho 83-153, HSF-242 and S-2002-US-133 were showed high tolerant against heat therefor, showed higher membrane stability, maintenance of high fv/fm ratio under heat stress and lower lipid peroxidation of membranes. Hence, the relative tolerance of genotype to heat stress as reflected by its lower lipid peroxidation, higher membrane stability and pigment concentration is related to the levels of activity of its antioxidant enzymes.

Simulation of Transport Phenomena during Natural Convection Cooling of Bagged Potatoes in Cold Storage, Part II: Mass Transfer

Moisture loss from potato is one of the most important economically significant parameters for long-term storage. It is a mass transfer phenomenon, which has strong relevance with heat transfer and fluid flow. Therefore, attempt was made in this study to model the moisture loss in a single bag packed with potato kept in cold store under natural convective environment using the computational fluid dynamics technique. It was found that in spite of high specific humidity, maximum moisture loss occurred in the upper half of the bag during the initial cooling period. As the cooling proceeded, the zone of maximum moisture loss shifted towards the bottom of the bag. The average rate of moisture loss in the bag at steady state was found to be 0·091% (w/w) [water] week−1. The contours of rate of moisture loss and specific humidity maintained symmetry about the vertical axis in a vertical plane and about both the horizontal axes in horizontal plane throughout the cooling process. The experimental total moisture loss was found to be 0·82% (w/w) against the simulated total moisture loss of 0·695% (w/w) over a storage period of 25 days.

ESTIMATION OF MOISTURE LOSS FROM THE COOLING DATA OF POTATOES

ABSTRACT A procedure was developed to predict moisture loss from cooling data of potato packed in gunny bags and stacked on wooden platforms in commercial cold stores. To predict the moisture loss, mass transfer coefficients kcand kmwere estimated during the storage period, which were found to decrease with time. The calculated time average kcand kmvalues were 1.83 × 10−4 m/s and 2.31 × 10−10 kg/s·m2·Pa during the transient cooling period and 1.59 × 10−4 m/s and 2.27 × 10−10 kg/s·m2·Pa for the rest of the storage period, respectively. The estimated moisture losses were 4.8, 4.74 and 4.78%, at the center of three different stacks, for a storage period of 8 months. The corresponding experimentally measured weight losses at the center of the same stacks were 5.2, 5.1 and 5.26% with a variation of 11, 7.5 and 10.2%, respectively. Therefore, the procedure adopted in this study may be used to assess the moisture loss from potatoes under the different storage conditions. The effect of relative humidity (RH) and potato temperature on moisture loss was also predicted using the developed procedure. Decrease in RH of the storage air increased the moisture loss. The potatoes stored below 85% RH incurred more than 7% water loss. Therefore, 88–90% RH in the cold store may be used to limit the maximum moisture loss within the permissible limit of 5% even after 8 months of storage. It was also found that increasing the potato temperature exponentially increased the rate of moisture loss.

Optimisation of processing variables in the preparation of sweet potato chips using response surface methodology

Models capable of predicting the product quality of sweet potato chips have been developed using response surface methodology and used to determine the optimum processing conditions. Moisture loss, oil uptake, crispness (measured using a bending-snapping test in the TA.XT2 Texture Analyser), and sensory attributes such as colour, flavour, and texture were used to assess the product quality in the preparation of sweet potato chips. The optimum conditions which were attained for maximum moisture loss (11.65% on wet basis), minimum oil uptake (2.57%), crispness (794.37 g), colour score (7), flavour score (7) and texture score (7) were: frying temperature, 174.7 °C; salt concentration, 0.45%; citric acid concentration, 0.37%; potassium metabisulphite concentration, 0.65%; and frying time, 26 s.

Effects of frying parameters on physical changes of tapioca chips during deep‐fat frying

The interrelationships of the effects of frying time, oil temperature, and initial moisture content on moisture loss, oil absorption, and linear expansion of a tapioca starch chip half‐product during deep‐fat frying have been studied. Both oil absorption and linear expansion were affected, in different ways, by moisture loss. Oil absorption was essentially a quantitative water replacement process. On the other hand, linear expansion occurred as a result of rapid vaporization of water in the initial stages of frying, but reached a plateau before maximum moisture loss. Critical frying times, temperatures, and initial moisture contents, below which virtually no physical change occurred, were observed. The optimum set of frying parameters for maximum linear expansion appears to be a frying time of 40 s, an oil temperature of 200°C, and an initial moisture content of 15% (dry basis).