Search

The feasibility of using a computer-vision (CV) system embedded in a hot-air dryer for non-destructive and real-time monitoring of the drying behaviour of organic apples was investigated in the present study. Apple cylinders were subjected to anti-browning treatments with different dipping solutions (water as control, trehalose (4% w/v) or trehalose + ascorbic acid (4% w/v and 1% w/v)) and dipping pressures (atmospheric, 101.3 kPa and sub-atmospheric pressure, 50 kPa) followed by drying at 60 °C to a final dry basis moisture content of 0.18 g g−1. The CV system was used as an in-line process analytical technology (PAT) tool to capture images reflecting the physico-chemical changes during product drying coupled with in-line mass changes and off-line reference analyses. The spatial and colour changes from the image analysis described well the complex and non-homogenous nature of apple drying. The results of spatial changes allowed successful development of accurate linear prediction models for moisture content as a function of area shrinkage (on scaled variables) with excellent prediction capability (|BIAS

One of the major challenges of the food industry is to develop more sustainable processing technologies. To address this change, it is necessary to have more information about available innovative technologies and their effect on different food matrices and processes to ensure efficiency in food chain management. The aim of this research was to increase the understanding of the physical modifications induced by the combination of pulsed electric field (PEF) pre-treatment and further drying in carrot and potato tissues by modelling the sorption isotherms and the textural properties. High coefficient of determination up to 0.980 for GAB and 0.977 for BET were obtained confirming the good ability of both models to describe the sorption isotherm of foodstuff. Either BET and GAB classified carrot in a III type shape and potato in II type shape for sorption isotherm. Mechanical properties for carrot and potato considering all PEF treatment and aw levels were reported and fitted by modified Fermi distribution. High coefficient of determination up to 0.995 confirm the ability of Fermi model to describe mechanical properties in relation to water activity (aw).

Recovering waste from industrial food processes and developing new healthy foods as plant protein sources has been a major focus of scientific research and industrial innovation in food. Thus, the consumption of plant-based beverages from soy, oat, or almond has been promoted. In the case of almonds, the resulting solid bagasse has an interesting nutritional profile and its transformation into a powdered product could be a valuable option for the food industry. The main objective of this work was to determine the effect of hot air drying at 60 and 70 °C and freeze-drying on the physicochemical, water interaction, emulsifying and antioxidant properties of powdered almond bagasse. Furthermore, hot air-drying curves have been modelled and isotherms at 20 °C have been performed. The proximate composition of the powder revealed a protein content of 15% and a fat content of 25%, which makes it a remarkably different powder from those obtained from other vegetable residues such as fruits and vegetables. This composition was decisive in the effect of the drying method and drying temperature, and no significant differences were observed on the physico-chemical or antioxidant properties regardless of the drying method used. However, freeze-drying resulted in a powder with a more homogeneous particle size distribution and better oil-interaction properties, especially with higher emulsifying activity and stability.

Fresh produce continues to be the main source of foodborne illness outbreaks in the United States, implicating bacterial pathogens such as Escherichia coli O157:H7 (EHEC). The efficacy of nanoemulsified carvacrol (NCR) as a washing treatment in reducing EHEC on fresh produce was investigated. Fresh baby spinach, romaine lettuce, and iceberg lettuce leaves (2.5-cm-diameter cores) were spot inoculated with a five-strain cocktail of nalidixic acid-resistant EHEC at ∼6 log CFU/cm2. After air drying for 1 h, 20 pieces of each inoculated produce leaf were immersed in water-based treatment solutions (200 mL per group), including water alone, 25 or 50 ppm of free chlorine, and 0.25 or 0.75% NCR for 2 min. Inoculated produce leaves without any treatment served as baseline. Produce leaves were stored at 10°C, and surviving EHEC populations were enumerated on days 0, 2, 7, and 14. The viability of EHEC following NCR treatments on the fresh produce was visualized under a fluorescence microscope. NCR treatment at 0.75% immediately reduced EHEC populations on iceberg lettuce by 1.3 log CFU/cm2 as compared with the produce treated with water alone (P0.05). Antimicrobial activity of NCR against EHEC was comparable to chlorine treatments on day 0 for all produce (P0.05). After 14 days of storage at 10°C, populations of EHEC on 0.75% NCR-treated romaine lettuce were reduced by 2.3 log CFU/cm2 compared with the recovery from 50 ppm of chlorine-treated samples (P0.05). Microscopic images revealed that EHEC cells were observed to be clustered on the baseline samples, indicating the development of cell aggregation, compared with the scattered cells seen on NCR-treated leaf surfaces. Treatments with NCR did not significantly affect the color of the fresh produce leaves during 14 days of storage at 10°C. Results of this study support the potential use of NCR as a water-soluble natural antimicrobial wash treatment for controlling EHEC on fresh produce.

Large amounts of sludge are generated from wastewater treatment in seafood processing industries. Most of the dewatered sludge in Thailand is not utilized and disposed by landfilling. The dried sludge utilization as refuse-derived fuel (RDF) is an alternative solution due to the gross calorific value (GCV), which is greater than 21.9 MJ/kg. However, the key obstacle is its high moisture content of 87.4% (wet basis). Therefore, drying methods using hot air and microwave techniques were investigated for preparing dried sludge. The effects of hot air temperatures (100-150 °C) and microwave power levels (100-800 W) were compared on drying kinetics, specific energy consumption (SEC), and characteristics of the dried products. The results showed that drying times were decreased by increasing the hot air temperatures. In the same way, the increase in microwave power levels decreased the drying time. The application of microwaves contributed to reducing the drying time by more than 46% compared to the hot air. The reduction of drying times resulted in the saving SEC. The GCV of the dried sludge decreased with the decrease in the volatile matter (VM) due to the high component of VM as 79.5-80.3% (dry ash-free basis). The sludge dried by the microwaves showed a lower GCV than the hot air products. However, dried sludges still had high GCV (≥ 20.8 MJ/kg). Furthermore, the minimal variation of the product characteristics demonstrated that the microwave technique could be applied as an alternative drying method with a rapid process compared to the conventional hot air technique.

The growth in the cost of raw materials, vehicles, fuel, incomplete use of the crop leads to an increase in the cost of grown products. As you know, in the process of harvesting and its marketing, about 25-35% are products not sold on time, non-standard products, which are not inferior in nutritional value to the standard and stripping products. Such products are discarded or partially sold by agreement. Processing this part of the crop by solar-air drying is one of the ways to reduce crop losses and make the cultivation technology low-waste and resource-saving.Materials and methods. On the basis of the All-Russian research institute of irrigated vegetable and melon growing – branch of Precaspian agrarian federal scientific center of the Russian academy of sciences (FSBSI “PAFSC RAS”), work was carried out to study the quality of dried eggplants of the institute's selection that were not realized in due time and cleanup collection. For work, they took the fruits of the varieties Nizhnevolzhsky, Panther, Almazny, Astrakom. The goal of the work is to ensure the protection of unsold marketable products, as well as the fruits of the stripping collection from spoilage and obtaining a new product with good nutritional and taste properties, which makes the eggplant growing technology low-waste. Before and after drying, the main chemical substances were determined: the amount of sugars, dry substances, ascorbic acid, nitrates.Results Our results prove that from each ton of unsold products, you can get from 80 to 106 kg of complete dietary products. Ready-made dried eggplants contain, depending on the variety, from 21.17 to 23.86% of the total sugar, the amount of ascorbic acid ranges from 1.63 mg /% to 2.61 mg /%. The amount of nitrates is 7.6-10.2 times less than the permissible (1200 mg / kg) level. Solar-air drying is low-cost, since its storage and transportation requires fewer containers and vehicles. The amount of dried products is reduced to the original, depending on the grade and weight of the loaded raw materials per square meter by 9.4-12.5 times.

Hot air drying is a common method for drying potato slices. In this paper, the three-dimensional (3D) morphological changes incurred during hot air drying of potato slices were investigated. The effect of drying on the thickness and diameter of potato slices was of special interest. The results showed that the potato slices underwent stages of regular warping, collapse, and curling during the drying process. After classifying the numerical variation in characteristics into the standard deviation in mean height (SDMH) and the rate of change in mean height (RCMH) of potato slices, the RCMH was selected to describe the 3D morphological changes in the potato drying process. A critical point and a termination point for RCMH of potato slices in the drying process were observed. Samples varied widely after the critical point was reached. A logarithmic function model was used to assess differences in the RCMH at the critical point and the termination point. The R-squared (R2) value of 0.9 suggested a strong correlation between the parameters of the experiment and changes in slice thickness and diameter. The model proposed in this paper could accurately characterize the late-stage changes in potato slice qualities during hot air drying of potato slices., Graphical abstract Image 1, Highlights • Drying potato slices underwent stages of regular warping, collapse and curling. • A correlation between the fitted results and the changes in thickness and diameter. • A height change model in the later stage of hot air drying of potato slices.

This study aimed to evaluate the drying rate of Eucalyptus urophylla hybrid logs of different lengths used for carbonisation. Six seven-year-old trees of two clones (VM4 and MN463) were harvested f...

The plant Morinda citrifolia L. (Noni) has been the subject of several recent research due to its positive impact on the treatment and prevention of a variety of diseases. Noni fruits contain a variety of phytochemicals, including flavonoid, polyphenol, and triterpenoid saponin. This study aimed to determine the best pre-treatment (including blanching, soaking in ascorbic acid solution and metabisulfite solution) and air-drying temperature (50, 60, 70, and 80 °C) to maximize the total polyphenol content (TPC), flavonoid content (TFC), and triterpenoid saponin contents (TSC) of the resultant Noni fruit powder. The results revealed that pre-soaked Noni fruit samples in ascorbic acid or metabisulfite solution before air-drying at 60 °C were beneficial in preserving TPC, TFC, and TSC. TPC, TFC, and TSC losses increased as drying temperatures (70 and 80 °C) rose. The optimum sample was held at five different relative humidity conditions until they attained weight equilibrium. The results indicated that the sorption isotherm curve of the Noni powder was the sigmoid shape and fitted with the BET and GAB models.

The aim of this study was to develop a coupled heat and mass transfer model to predict the temperature and moisture content of beef during biltong processing using infrared-assisted hot air drying (IRHAD). The developed model was implemented and solved using Ansys Fluent CFD software. Drying experiments conducted using an infrared-assisted hot air dryer were used to determine the moisture diffusivity, and the heat and mass transfer coefficients used in the model. The experiments were done at an infrared emitter power level of 750 W; drying air temperature of 30, 35, and 40 °C; and velocity of 1.5 and 2.5 m s−1. The simulation slightly overpredicted the temperature in the first hour of drying and underpredicted the temperature towards the end of the drying period. Consequently, the predicted moisture ratio (MR) was underpredicted at the onset of drying and agreed with the experimental values towards the end of the drying period. The simulation results were validated using a new set of experimental results, and the suitability of the model assessed using the R2 (0.9790 for temperature and 0.9579 for MR) and RMSE (1.99 for temperature and 0.0698 for MR). The model can guide the application of IRHAD in the processing of biltong and forms a theoretical basis for analysing the application of IRHAD to other food and biobased products.

Moisture content and carotenoid content are important indicators for evaluating the drying process of carrot slices. There are growing attention to develop non-destructive methods as effectively analytical tools in quality assurance of drying carrot slices. In this study, the characteristic wavelengths of moisture and carotenoid content in carrot slices during hot air drying were extracted based on hyperspectral imaging technology. A multispectral imaging equipment was built after that, and the wavelengths of filters were determined according to the characteristic wavelengths. Based on the successive projection algorithm (SPA), the optimal wavelengths of moisture and carotenoid content were further determined, and prediction models of both were established based on the system. There were 12 filters selected in this study. The results showed that a support vector machine (SVM) prediction model for moisture content was established based on seven optimal wavelengths with 0.991 for the coefficient of determination of prediction set (R 2 p ) and 10.318 for the residual prediction residual (RPD). Based on eight optimal wavelengths, a SVM prediction model for carotenoid content was also established with 0.968 for R 2 p and 5.337 for RPD. The prediction performance is close to or even better than that based on hyperspectral. The study confirmed the feasibility of using the multispectral imaging equipment to measure the moisture and carotenoid content of carrot slices during drying based on selected wavelengths, laying a foundation for the further preparation of a portable multispectral detector for the quality of dry products.

Aims: Button mushrooms, rich in vitamins and minerals, are very highly perishable and therefore, it has been very necessary to develop a value-added product. The aim of the research work is to study the effects of blanching on air-dried, microwave oven dried, and freeze dried mushroom samples and also to study the characterization of dried samples. Place and Duration of Study: Department of Agricultural Engineering, School of Agricultural and Bio-Engineering, Centurion University of Technology & Management, between February 2021 to June 2021 Methodology: Three different drying techniques like hot air, microwave, and freeze drying were taken to study the drying effect on dried mushroom slices. The quality parameters like dehydration and rehydration potential, density, ascorbic acid, color, and organoleptic properties were studied. Results: The rehydration ratio of freeze dried mushroom samples were high having low density than the other dried samples. Less color deterioration was also found in freeze drying. Moreover, ascorbic acid, color, texture, and overall acceptability of sensory analysis were found to be maximum in freeze dried samples. The freeze dried product was found to be attractive in flavour and texture and got highest score in sensory analysis. Conclusion: The freeze drying can be an effective drying method to dry fresh mushroom compared to hot air and microwave drying.

Drying temperature, air velocity, material thickness during hot air drying usually have a significant influence on drying kinetics and quality attributes of fruits and vegetables. However, under co...

The brine temperature (X1), the NaCl concentration (X2), the drying temperature (X3), and the drying time (X4) were the 4 parameters explored in this study, which aimed to model the OD-Drying coupling of fresh tomato. A 4 factors Box-Behnken experimental design associated to the response surface methodology (RSM). A transformation of the usual quadratic model was necessary to fit the experimental results. From the obtained models, relationships between the studied factors and the followed responses were establish. From the multicriteria optimization, the following conditions were found as optimal: X1 = 65 ?, X2 = 5%, X3 = 43.88 ? and X4 = 24h. The tomato powder obtained by reproduction of optimal conditions showed better properties than the tomato powder produced by local farmer by sun drying, but similar characteristics as the concentrate prepared from it. From the fresh tomato to the tomato powder obtain using the optimal conditions, the overall quality lost is relatively low.

Purple cabbage is one of the world's most widely consumed vegetables with high nutritional values containing the antioxidants and anti‐inflammatory activity of anthocyanins, vitamins, and minerals. But due to rapid postharvest quality decay, novel processing techniques including drying are required. In order to determine the conditions of combined microwave and hot air drying for purple cabbage, factors affecting the drying process including microwave density, hot air temperature, and the dry base water content at conversion point were investigated using the anthocyanin content, DPPH antioxidant capacity, chewiness, △E, rehydration ratio, and average drying rate as responses. The combined drying conditions were optimized considering three independent variables at three different levels by response surface methodology. The results showed that the processing parameters of purple cabbage with combined microwave and hot air drying technology were microwave density at 2.5 W/g, moisture content of conversion point at 4.0 g/g, and hot air temperature at 55°C. Under these conditions, the anthocyanin content, DPPH antioxidant capacity, chewiness, △E, rehydration ratio, average drying rate, and overall score of the dried purple cabbage were 175.87 mg/100 g, 87.59%, 4,521.468 g, 26.5, 4.3, 0.76 g/min, and 0.785, respectively. Therefore, combined microwave and hot air drying technology is an effective, suitable method for drying purple cabbage., In this paper, we study the effects of microwave density, hot air temperature, and moisture content at conversion point on the quality of purple cabbage. We also optimize the parameters of combined microwave and hot air drying by response surface methodology (RSM).

Mode for hot air drying of alder blanks that retain the colour acquired during the steaming process. The paper presents a hot-air mode for drying steamed alder in the form of blanks with dimensions: 38x100x800 mm from the initial moisture content W1 ≈ 50 % to the final moisture content W2 = 10%, while maintaining the colour of wood obtained in the process of steaming with saturated water steam. The drying process is divided into two parts: (I) evaporation of free water from wet wood at drying medium temperatures td = 35 - 40 °C and relative air humidity φ = 70 – 60%, when there are no chemical changes in the lignin-saccharide complex of alder wood manifested by a change in colour; (II) evaporation of bound water from alder wood below the hygroscopicity limit is performed at temperatures td = 60 - 80 °C. The color coordinates of steamed alder wood after drying by a given mode in the CIE L* a* b* colour space are: L* = 62.5 ± 1.7; a* = 13.1 ± 0.8; b* = 18.5 ± 0.9. Total colour difference ∆E = 1.6. According to the categorization of wood color changes in thermal processes of wood , this change belongs to small (insignificant) color changes.

Durante mucho tiempo las plantas medicinales fueron el principal recurso disponible para tratar enfermedades. Por esta razón fueron desarrollándose numerosos estudios sobre esas plantas e investigaciones sobre el uso de sus productos y derivados. La china konoca (Xenophyllum poposum) es una planta nativa que crece de manera silvestre en los Andes peruanos a más de 4400 metros sobre el nivel del mar, es muy utilizada como una infusión natural para la digestión. El propósito de este trabajo fue realizar un modelado matemático durante el proceso de deshidratado de la china konoca (Xenophyllum poposum). Para ello, se efectuó la evaluación de cinética de deshidratado de esta planta a 60°C y 80°C, durante 480 y 600 minutos, en donde se hizo las mediciones de pérdida de humedad. Se obtuvieron gráficas de velocidad de deshidratado en función del tiempo, temperatura y la humedad, con estos datos se realizó un modelado matemático de cada tratamiento para describir la tendencia en las curvas de deshidratado. Resultando un modelo polinómico de segundo grado el que mostró mejor bondad de ajuste en la cinética de secado por aire caliente, %H = a – b ? +c ? 2. Además, se hizo el modelamiento para predecir el tiempo de equilibrio en el decrecimiento de humedad, derivando la ecuación anterior, ?=b/2c.

Finger citron is a kind of rare Chinese traditional medicine. The effect of different drying techniques (hot air drying 60 °C, microwave drying 60 °C, freeze drying −50 °C and −0.08Mpa) on the quantity and quality parameters of the final product analyzed by gas chromatography–mass spectrometry, E-nose and sensory profile methods was investigated. Eleven drying models were used for finger citron slices within the experimental range and Midilli et al. model and Weibull model were suitable. Results showed that microwave drying and freeze drying were optimal drying methods to preserve color, volatiles, and obtain higher sensory points. However, freeze drying had long drying time. With a view to the quality retention and time, microwave drying would be very promising for finger citron slices.

The drying kinetics and quality characteristics of three potato (Solanum tuberosum) cultivars (Agria, Granola and Marabel) cut into circles and squares were studied at 60 °C and 70 °C using a convective drier. Drying times were varied between 105 and 220 min depending on variety, shape and temperature and falling rate period was observed during hot air drying. Four mathematical models were fitted to the experimental data. A logarithmic model was found to be the best for all the samples. The results showed that the drying kinetics of potato were significantly affected by variety, shape and temperature. Drying rate was found to be the highest in variety Marabel and it increased with the increase in temperature and was also higher in square-shaped potatoes than circle-shaped ones. Variety significantly affected the total polyphenol content (TPC) of dried potatoes, whereas variety, shape and their interactions had significant effects on their antioxidant capacities (AC). After drying, the highest TPC and AC were recorded for variety Agria. Concerning colour properties, while the drying temperature and shape had a significant effect on L value, variety and shape significantly affected other colour values of potato samples. These results demonstrated that when choosing the most suitable variety for convective drying of potato, it is necessary to consider the quality characteristics as well as the drying kinetics.

Thin Pale Crepe (TPC) products are currently increasing in demand by rubber product manufacturers. Its production process is relatively more efcient than crumb rubber, which is Indonesia’s main product. The drying of TPC products still uses air drying from the burning of rubberwood. The use of rubberwood is predicted to be less economical in the future. With an increasing limited natural forest, rubberwood will be an alternative substitute for wood from natural forests. As a result, the economic value of rubberwood will be even greater which will have an impact on the increasing cost of TPC products if it continues to use rubberwood as fuel. Therefore, we need an alternative to rubberwood as an energy source for drying TPC. Sunlight can be an alternative source of energy that can be maximized for the drying process of natural rubber, including in TPC production. This research was conducted in two stages, namely 1) the production of TPC using latex from various clones with several additive dosages, and 2) TPC drying using various renewable energy sources. The results of research activities are in the form of a technology package regarding the TPC production process using renewable energy sources. The results showed that the TPC products produced with various treatments fulflled SNI 1903-2000. The three clones (BPM 24, PB 260, and GT 1) were able to produce TPC with bright yellow color.

Background Shiitake mushroom is one of the most popular delicious vegetables, although fresh shiitake mushroom has short shelf life as a result of biochemical degradation. Drying can prolong the shelf life of mushroom. Additionally, application of cold plasma pretreatments (CPT) before drying can preserve the product quality, processing costs and nutritional values. Therefore, we aimed to explore the effect of cold plasma pretreated hot-air drying at 50, 60 and 70 °C on the physicochemical characteristics, nutritional values and antioxidant activity of shiitake mushroom. Results Scanning electron microscopy micrographs showed that CPT induced the surface modification of fresh shiitake (such as cellular disarrangement, cellular shrinkages, disruption or break down of cell walls, and intracellular spaces and cavities) and facilitate the rapid drying than control samples. Furthermore, CPT improved the powder qualities (bulk density, water retention and swelling index) and preserved higher nutritional attributes (sugars, vitamins, phenolic acids contents and antioxidant activity) compared to the control groups. Conclusion Conclusively, CPT could be a suitable alternative technique for improving drying characteristics and preserving nutritional attributes of agro-based products. © 2021 Society of Chemical Industry.

Collective farming is an agricultural practice in which the farmers join together and carry out the farming activities in a collective manner. The scheme was brought up in the year 2017 in order to improve the lives of the small and marginal farmers. The present study deals with the constraints faced by the farmers in practicing collective farming. The study was performed in the Tirunelveli district with the sample size of 120 farmers. The data were collected using interview schedule. The recorded data were analyzed using percentage analysis. The foremost constraint faced by almost all the farmers of the collective farming group was the excess amount for the machinery purchase to be managed and met out by the member farmers on their own. Suitable measures can be developed to minimize the constraints faced by the farmers for the better adoption of collective farming.