Dehydration Of Fruits Research Articles

Flavour chemistry of dehydrated exotic fruits

Dehydrated fruit pieces and purées are commonly used in many food formulations and toppings for food products like yogurts, ice creams, and cereals. However, one of the biggest problems in fruit dehydration is the prevention of the development of unpleasant off-flavour that can negatively impact on the sensory quality of the final dried fruit products. In recent years, fruit dehydration has been conducted using either thermal or non-thermal drying techniques. Therefore, the present review examines how the different dehydration technologies, namely conventional hot air-drying, ultrasonic-assisted hot air-drying, sun-drying, spray-drying, Refractance WindowTM drying, cast-tape drying, thin-layer catalytic far-infrared radiation drying, withering, freeze-drying, microwave-drying, and osmotic dehydration impact on the volatile constituents of the final dried fruit products. Drying processes result in noticeable losses/reduction of several impact odorants. Moreover, some compounds are produced either via: (1) hydrolysis of relevant glycosides under high temperatures, or (2) thermal degradation of volatile and non-volatile precursors as well as oxidation and Maillard reactions which result in the production of heterocyclics, and saturated and unsaturated aldehydes. Of significance is the Refractance WindowTM drying which exhibits high retention potential (~ 90%) of volatile compounds present in fresh fruits. Refractance WindowTM drying technology ensures rapid drying of food products at very low temperature.

Sugar profiles modulation of mangoes during osmotic dehydration in agave syrup solutions.

Chemical interaction and multicompound competition were investigated on solids gain and carbohydrate profiles evolution during osmotic dehydration of mangoes. Tommy Atkins mango slices (0.4cm and 1.5cm thickness) were osmotically processed at 40°C for up to 4h and 8h, respectively. Osmotic solutions (60 °Brix) were separated in two categories: single solute (sucrose, glucose, fructose) and multisolute (agave syrup, alone or with additions of 5% inulin or 0.1-0.3% xanthan gum) solutions. High performance liquid chromatography (HPLC) analysis was carried out on treated mango to determine sugar profiles evolution during osmotic dehydration and final product concentrations. Findings pointed out that composition of osmotic solution may modulate mango sugar profiles by triggering uptake or loss of sugar according to different phenomena: chemical potential gradient, lixiviation, prevailing mass transfer, formation of carbohydrate barrier, and solution viscosity. Mango was enriched with the solute present in the single solute osmotic solution, while it lost its own native sugars, which were absent in the osmotic solution. Increasing sample thickness reduces individual sugar uptake or loss in mango treated with both single and multisolute solutions. Significant differences in mono solute solution behavior were found for sucrose due to its capability to form a sugar layer outside the surface of thicker samples, which was shown by scanning electron microscopy (SEM) images, a barrier markedly hindering the sucrose uptake or loss. Addition of polysaccharides (particularly xanthan gum) was found to have an impact of lowering mango individual sugar uptake (18-30%). Practical Application These results will help in understanding the mechanisms by which gain of individual sugars could be reduced and composition could be modulated during osmotic dehydration of fruits. Thus, the findings in this work could lead to production of low-sugar content, osmotically processed mango snacks, enriched with inulin, enhancing their dietary and marketable value.

Ultrasound as pre-treatment for microwave drying of Myrtus communis fruits: Influence on phenolic compounds and antioxidant activity

Background: Drying constitutes the most common method of food preservation that may degrade nutrients compounds in fruits due to high temperatures and long drying times. Myrtus communis is one of the important aromatic and medicinal species, owing to these reasons, the development of new methods of drying is essential for the preservation and valorization of myrtle fruits. Aims: The aim of the present study was to investigate the effect of ultrasound as a pre-treatment (USP) at 10 min to 90 min in microwave-drying (MD) on the dehydration of myrtle Myrtus communis fruits, on phytochemical content, and on antioxidant activity. Methods: ultrasound drying as pretreatment in microwave drying, extraction yield efficiency and antioxidant activity were measured using radical scavenging assay (DPPH•) and reducing power in addition the PCA analysis was investigated to detect the relationships between variables. Results: The ultrasound pretreatment reduced notably the microwave drying time. A pretreatment of 90 min provided the most rapid drying kinetics (6 min and 5.5 min for 500 w and 700 w respectively) compared to the microwave drying alone (18 min and 11 min for 500 w and 700 w respectively). A higher phytochemical content; 219.90 ± 0.69 mg GAE/g for total phenol content (TPC) was obtained compared to those from MD and conventional drying (CD); 193.79 ± 0.99 mg GAE/g and 148.16 ± 0.95 mg GAE/g for TPC respectively. Indeed, the antioxidant activity tests revealed that ultrasound pretreatment is one of the most efficient methods to preserve the quality and the hydrogen and/or electron-donating ability of antioxidants for neutralizing DPPH radicals (98.63 %) test and reducing ferric ions to ferrous ones. Effectively, the results of PCA analysis show a higher positive correlation between antioxidant activity and flavonoids, anthocyanins, and tannins contents. Conclusions: Ultrasound pretreatment is expected to be a potential alternative to preserve fruit quality during microwave drying because it can reduce drying time at ambient temperatures while preserving natural heat-sensitive nutritive components, flavor, and color. Keywords: Ultrasound, Myrtus communis L, microwave, drying, pretreatment, antioxidant activity.

Ultrasound assisted osmotic dehydration of dragon fruit slices: Modeling and optimization using integrated artificial neural networks and genetic algorithms

The effect of ultrasonication on osmotic dehydration of dragon fruit (Hylocereus undatus) slices was investigated using a feed forward backpropagation neural network in this study. The four process variables were ultrasonic power ( X UP $$ {X}_{UP} $$ : 100–300 W), ultrasound temperature ( X UT : $$ {X}_{UT}: $$ 30–50°C), osmotic solution concentration ( X SC $$ {X}_{SC} $$ : 40–60°Brix), and liquid to solid ratio ( X LS $$ {X}_{LS} $$ : 8:1–12:1 ml/g). Under different combinations of independent variables, the water loss ( Y WL $$ {Y}_{WL} $$ ), solid gain ( Y SG $$ {Y}_{SG} $$ ), and change in color ( Y ∆ E $$ {Y}_{\Delta E} $$ ) were evaluated. The ANN architecture consists of 4, 9, and 3 neurons in the input, hidden, and output layer, respectively. The three independent variables of ultrasound-assisted osmotic dehydration X UP $$ {X}_{UP} $$ , X UT $$ {X}_{UT} $$ , and X SC $$ {X}_{SC} $$ found to have a positive effect on the three responses water loss, solid gain, and change in color. The liquid to solid ratio was revealed to have a negative effect on color change and a positive impact on response water loss and solid gain. The output parameters of the ANN model (weights and bias) were integrated with genetic algorithm (GA) for the optimization purpose, and the best combination was picked based on the fitness value (FV). The optimal ultrasound-assisted osmotic dehydration condition obtained using integrated ANN-GA was 235 W, 38.74°C, 56°Brix, and 10.5 ml/g. The relative deviation between the experimental and integrated ANN-GA model predicted values for water loss, solid gain, and color change values under optimum conditions was less than 6.880%, suggesting that the predicted values for response were in good agreement with the experimental data. Practical applications The article describes the synergistic influence of sonication power and temperature on the osmotic dehydration of dragon fruit slices. Ultrasound-assisted osmotic dehydration (USOD) prevents enzymatic and oxidative browning, preserving the color. In dragon fruit slices flavor retention increases when sugar syrup is used as an osmotic agent. Furthermore, the fruit pieces absorb sugar and eliminate acid, resulting in a sweeter product than a conventionally dried product. The results showed that ultrasound assisted osmotic dehydration removed water from dragon fruit more rapidly at a lower temperature, keeping color, aroma, nutritional value, and flavor components. The combined impact of ultrasound and temperature also lowered the water activity of fruit and enhanced the product's storage life significantly.

Detecting Freshness of Fruit and Vegetable Without and With Edible Protein-Based Foil

In recent years, food packaging has become essential, both for producers and consumers. The increasing use of food packaging has a major impact on food quality, but also on the environment. Ripening, freshness and quality of fruit and vegetable from field to the table became increasingly demanding in the food industry. The classical approach to maintain the freshness of fruits and vegetables after cutting is based on use of plastic foils, which is not eco-friendly and increases plastic waste. The purpose of this study is to explore the possibility of maintaining the freshness of chopped and cut fruits and vegetables using materials based on biopolymers such as protein-based films. Comparing to the most used films and coatings for food packaging, plant protein-based films are edible, biodegradable, vegetarian- and eco-friendly. Non-destructive method used for characterization of freshness during time was electrical impedance spectroscopy connected to the transmission line-based platform. The aim of this work was to correlate the bioelectrical impedance variation with ripening and dehydration of fruit and vegetables (pear and zucchini) without and with a wrapped protein-based films. The impedance of the samples on the microchips was measured at frequency sweeps ranging from 2 kHz to 200 kHz for 39 points. The results demonstrated that the bioimpedance increased with the progresses in fruits and vegetable ripening. For a better understanding of the underlying processes, we provided an equivalent electrical circuit with physical interpretation of circuit elements. Changes of model parameters with time showed excellent correlation with fruits and vegetable ripening.

Sistem pentru deshidratarea fructelor cu eficiență energetică înaltă

The paper is dedicated to streamlining the process of fruit dehydration, by microwave treatment in the tunnel, mainly by reducing electricity consumption. To address this issue, an experimental system for fruit dehydration was developed, thus the research being conducted applying a tunnel-type dehydrator. The experiments were performed on the example of apricots, peaches and plums. The results obtained with the application of the experimental system were compared with those obtained based on the classical dehydration technology. Fruit dehydration based on the developed system reduces the consumption of electricity by about 1.37 times, compared to the application of classical technology.

Osmotic dehydration of fruits using unconventional natural sweeteners and non‐thermal‐assisted technologies: A review

In the food preservation process, drying or dehydration reduces the moisture content that is needed for the growth and multiplicity of microorganisms that cause food spoilage. Among the most effective and appropriate methods for extending the shelf life of fruits and vegetables is osmotic dehydration. This process encourages the movement of water molecules from the food to the osmo-active solution and a small amount of solute from the solution into the food, resulting in an organoleptic and functional product. Sugar, which is the most popular osmotic agent, presents many health risks. Therefore, this review discusses the mechanisms of osmotic dehydration and the use of unconventional natural sweeteners like honey, jaggery, coconut sugar, stevia, and sugar beet molasses as an osmotic agent. Furthermore, certain non-thermal methods to help osmotic dehydration have been reviewed that may improve the drying and quality parameters of different fruits. Practical applications The osmotic dehydration process in fruits reduces postharvest losses, as well as maintaining the initial fruit characteristics such as color, aroma, texture, and nutritional content. The uses of natural sweeteners viz. jaggery and honey as osmotic agents have numerous health benefits. Due to these benefits, it can be used at small scales, home-scale industries, and large-scale industries. Various methods can be used to enhance osmotic dehydration, such as pulsed electric fields, high pressure, vacuum, microwave, centrifugal force, or ultrasound, which can be applied to large-scale industries.

Low-Energy Fruit Dehydration Method

This article describes a low-energy fruit dehydration method. To evaluate the effectiveness of this method, an experimental fruit dehydration plant of the tunnel type was developed, on the basis of which the studies were carried out. Convection and microwaves have been used to treat the fruits during the dehydration process. The results obtained on the basis of the proposed method were compared with those obtained when using the classical dehydration method. Thus, studies have shown that dehydration of fruits by the new method allows of reducing electric energy consumption by 4.69 times.

Effect of Biological Combined with Ultrasonic Extraction and Solvent Extraction on Resveratrol and Anthocyanin Content of Ripe Mulberry Fruits

Resveratrol and anthocyanins are important photochemicals that had high potential for health benefits. Thailand can produce a lot of mulberry fruits that are able to use for as raw material for resveratrol and anthocyanin extraction. This research aimed to find out the optimal process for resveratrol and anthocyanin extracted from ripe mulberry fruits. Mulberry fruits from Chiang Mai variety which were harvested from mixed ripening stage were suitable for using as raw material, because of its high value of resveratrol and anthocyanin content. In this study, two extraction methods were investigated; biological extraction and solvent extraction methods. From biological extraction without ultrasonic treatment and without deacidification, it was found that resveratrol content was increased during yeast fermentation. After filtration, fermented mulberry fruit solution had very high recovery value of resveratrol (331.97%) from fresh ripe mulberry fruits. From solvent extraction, preliminary dehydration of fresh ripe mulberry fruits decreased the amount of resveratrol and anthocyanin content. So that fresh ripe mulberry fruits without dehydration was suitable to use as raw material. Mulberry juice and cake was obtained from hydraulic pressing of fresh ripe mulberry fruits. It was found that mulberry fruit cake had high resveratrol content approximately 2/3 of whole resveratrol content. In this study, mulberry fruit cake was selected as raw material for solvent extraction. Room temperature extraction of mulberry fruit cake with mixed solvent (ethanol:ethyl acetate = 50:50) at the ratio of 1:5 for 1 hour soaking time could provided 104.24% of resveratrol recovery from fresh ripe mulberry fruits. According to resveratrol recovery, the high potential method for resveratrol extract should be biological extraction. The extract solution with high resveratrol content could be utilized as concentrate or powder forms.

Effect of osmotic agent and vacuum application on mass exchange and qualitative parameters of osmotically dehydrated strawberries

Sucrose is the most commonly used solute in the osmotic dehydration (OD) of fruits. However, there is increasing interest in replacing it with other alternative sugars. Polyols are carbohydrates with low glycemic, insulinemic, and cariogenic indexes. Therefore, this work aimed to study the influence of the type of osmotic agent (sucrose, erythritol, or maltitol) and vacuum application on mass transfer and physical and nutritional changes in 10-mm edge strawberry cubes. OD was performed with or without vacuum application during the first 20 min in a total process time of 300 min. Higher solid gain, water loss and weight reduction, and lower water activity and moisture content were observed by using erythritol solution. The vacuum application strengthened this behavior. The color of the samples was affected by factors. Osmotic processes reduced the total anthocyanin content (TAC), showing that leaching is an important qualitative flow during osmotic processes. Novelty impact statement Polyols showed good potential as an osmotic agent in the osmotic dehydration of strawberries and are a good alternative to the use of sucrose. Osmotic dehydration promoted a satisfactory impregnation of polyols in the strawberry, mainly with the application of vacuum, in which the mass exchange rates were increased. However, leaching was an important flow of anthocyanin loss from strawberries to the osmotic solution.

AN OPERATIONAL EVALUATION OF A TECHNOLOGICAL LINE FOR INDUSTRIAL DRIED CHERRY PRODUCTION BY THE OSMOTIC-CONVECTION METHOD, COMPARED TO A LABORATORY SCALE

Background. Pre-osmotic dehydration of fruits may significantly reduce free water content. It also causes fruit penetration by solution components, increasing the efficiency of products manufactured by the osmotic-convection method. A study was carried out on a laboratory and industrial scale to perform an operational evaluation of a technological line for dried cherry production. Frozen pitted cherries (Łutówka variety) were the research material. Sucrose solution, concentrated apple juice, and sucrose and glucosefructose syrup mixture (1:1) were used for OD; with 70±2 °Brix at 40, 55 °C (an industrial scale), and 50 °C (a laboratory scale) to obtain ≥ 60 °Brix of fruit extract. Industrial convection drying was carried out at 70 °C until the water activity of < 0.6 was reached. Results and conclusion. Increasing the osmoactive solution temperature enhanced the efficiency of a process aimed at fruit saturation by an osmotic substance and shortened the treatment time. Higher dehydration efficiency resulted in shorter convective drying time. No impact of the osmotic solution type on most mass exchange indices in dehydrated fruits was found. Despite the significantly higher process efficiency of the pre-dehydration in apple juice concentrate and drying stages, there was no significant impact of the solution type on the total process efficiency expressed as the ratio of dried mass to raw material mass. In spite of the same variants of osmotic dehydration of cherries in both production scales, the dehydration time under industrial conditions was even 11times longer. The technical condition of the tested line was determined as operable. The osmotic dehydration and drying equipment was working correctly. The complexity of repair processes and time-consuming equipment cleaning were demonstrated.

Characterisation of internal oxygen concentration of strawberry (Fragaria × ananassa) and blueberry (Vaccinium corymbosum).

Gas exchange mechanisms play crucial roles in maintaining fruit post-harvest quality in perishable fruit such as strawberry (Fragaria×ananassa Duch.) and blueberry (Vaccinium corymbosum L.). The internal oxygen concentration ([O2 ]) of strawberry and blueberry were measured using Clark-type oxygen sensing electrodes. The volume of intercellular voids in strawberry was obtained by micro-computed tomography (micro-CT). In both berries, internal [O2 ] was consistent and relatively high across measured tissues. The overall [O2 ] was well above the Michaelis constant (K m ) for cytochrome c oxidase in both fruit and different from previously examined grape (Vitis vinifera L.) berry mesocarp with near zero minimum [O2 ]. In strawberry and blueberry, cell vitality was also maintained at full maturity in the mesocarp. Higher storage temperature (i.e. 20 vs 4°C) reduced internal [O2 ] of strawberry. Pedicel detachment in blueberry was associated with greater fruit dehydration and lower internal [O2 ] after short-term storage of 12h. The results suggest that the intercellular voids of the fruit's mesocarp provide an efficient gas exchange route for maintaining high fruit internal [O2 ] post-harvest.

Sequential phenolic acid co-pigmentation pretreatment and contact ultrasound-assisted air drying to intensify blackberry drying and enhance anthocyanin retention: A study on mass transfer and phenolic distribution

In this work, the spraying of ethanol solution containing phenolic acid (ferulic acid or caffeic acid) was performed before subjecting to contact ultrasound-assisted air drying of blackberry. The mass transfer modeling results revealed that sonication intensified both internal water diffusion and external water exchange during drying, and ethanol pretreatment enhanced the effective diffusivity of water. Compared with air drying alone, the drying time for sequential ferulic acid pretreatment and drying with sonication was shortened by 89.2%. Owing to the co-pigmentation between phenolic acid and anthocyanins, the retention of anthocyanins was significantly enhanced after dehydration. At the end of drying, the total anthocyanin contents in the ultrasound-dried samples pretreated with ferulic acid and caffeic acid were 25.3% and 10.5% higher than the sonicated samples without pretreatments, respectively. Furthermore, drying simultaneously with sonication promoted the preservation of non-anthocyaninic soluble phenolics including catechin, phloretic acid, rutin in blackberry compared to air drying alone. Besides, bound phenolics in blackberry were less influences by the applied dehydration treatments. This study demonstrates that the combination of phenolic acid co-pigmentation pretreatment and ultrasound drying could be a promising method to protect anthocyanin pigments during dehydration of berry fruits.

Determination of the Best Method of Dehydration of Tropical Fruits to be Incorporated in Gelatin-based Dessert with Unaltered Sensory Qualities

Background: Jelly based desserts are very popular among millions of people worldwide. The main gel forming ingredient used in these products is ‘Gelatin’, which is a complex polysaccharide in their chemical structure. This research study focusses on incorporation of fruit pieces in to the dessert jelly in order to give a novel experience to the consumers. Methods: To determine the best way of incorporating fruit pieces in a commercially available jelly mixture (which is made up of fruit flavour, acid, water, sugar and pectin as the jelling agent), fruit pieces were treated in two ways and compared for the best textural and sensory qualities. First sample constituted unblanched, oven dried fruit pieces in a commercially available jelly mixture and its was compared with a jelly sample with blanched (fruit pieces were pretreated to minimize any possible discolorations and textural changes), osmo air dehydrated and oven dried fruit pieces. Sensory qualities such as texture, mouth feel and flavour of two different samples were gauged through a sensory test. Result: From a sensory test carries out by a panel of 09 sensory panelists it was found that the jelly mixture when incorporated with osmo air dehydrate fruit pieces it did not degrade the texture of the final product as opposed to unblanched dried fruit pieces does. The osmo air dehydrated fruit pieces in the prepared jelly has a texture and an acceptable mouth feel which is closer in texturally to the natural mouth feel and the taste, when they are reconstituted inside the jelly mixture by absorbing the water from the mixture.

Avocado dehydration negatively affects the performance of visible and near-infrared spectroscopy models for dry matter prediction

This study aims to test the hypothesis that skin dehydration can cause the development of cork-like layers in the avocado fruit skin which may negatively affect Vis-NIR spectroscopy. To test this, dehydration treatment was applied on avocado fruit by storing them at low relative humidity (RH) during ripening treatment. Furthermore, to demonstrate that the hypothesis was not only valid for a single instrument and in general valid for any type of Vis-NIR instrument the avocados were also measured with two different spectrometers i.e., lab-based, and hand-held. Since the two instruments have two different measurement geometries i.e., diffuse reflection and interaction, the study also tests which geometry was best for the measurement of DMC in dehydrated avocados. The results showed that the dehydration of avocado fruit negatively affects the performance of Vis-NIR calibrations compared to the non-dehydrated fruit. The root mean squared error of cross-validation (RMSEcv) on internal test set for dehydrated and non-dehydrated fruit were up to 1.49 % dw/fw and 1.02 % dw/fw, respectively. The hypothesis was true for both lab-based and hand-held instruments, and the root mean squared error of prediction on internal test set were up to 28 % higher for dehydrated fruits. The performance of interaction measurement mode was better (RMSEcv = 0.98 % dw/fw) than the diffuse reflection mode (RMSEcv = 1.21 % dw/fw) for non-dehydrated fruit, however, both modes achieved similar performance (RMSEcv = ∼1.42 % dw/fw) for dehydrated fruit. The poorer performance of Vis-NIR models on dehydrated avocado fruit can be accepted as a limitation of Vis-NIR spectroscopy for avocado fruit analysis.

Plastic Cutlery Alternative: Case Study with Biodegradable Spoons.

Plastics are mixtures of organic polymers that play a major role in environmental contamination worldwide. One way to reduce the waste arising from the use of plastics, especially disposable ones, can be to produce environmentally friendly cutlery. The aim of the work was the production of biodegradable spoons and evaluation of their texture, antioxidant activities and total polyphenols content. The spoons were made from a combination of the following ingredients: water, grape, proso millet, wheat, xanthan and palm oil in different concentrations. The samples were baked at 180 or 240 °C, some spoons were dried in a fruit dehydrator. According to the results of the analysis, a spoon prepared from a mixture of all three flours and with the addition of xanthan appears to be the most suitable replacement for plastic cutlery. This spoon showed high strength and antioxidant activity. It was confirmed that the use of grape flour has a beneficial effect on the nutritional profile of the experimentally produced biodegradable spoons.

Physical Field-Assisted Osmotic Dehydration Technology and Its Application in Fruit and Vegetable Drying

Osmotic dehydration is a non-thermal processing technology that can promote the dehydration of fruits and vegetables while maintaining their sensory and functional properties and extending the shelf life. However, the main disadvantage of osmotic dehydration technology is the low mass transfer efficiency. Physical field assisted osmotic dehydration technology can effectively improve the efficiency of osmotic dehydration. Physical field assisted osmotic dehydration technology includes ultrasonic, gamma ray, pulsed electric field, vacuum and high hydrostatic pressure assisted osmotic dehydration. Physical field assisted osmotic dehydration technologies and their application in fruits and vegetables are studied in this paper and some new research progresses and the problems are discussed. The mechanism and factors affecting mass transfer efficiency of osmotic dehydration, physical field assisted osmotic dehydration technology, dynamic model and the application of physical field assisted osmotic dehydration in fruit and vegetable drying are discussed.

Fast field cycling 1H-NMR relaxation properties during convective dehydration of mango fruits

The cultivation of mango fruits is increasing in the Mediterranean areas, including Italy, where a niche production has developed in the Tyrrhenian coast of Sicily. These fruits are rich in antioxidant substances, presenting a pleasant taste and aroma, fundamental qualities for the sensory acceptance of consumers. However, being climacteric fruits, mangoes are highly perishable, due to their rapid ripening after harvesting. As a result, large amounts of mangoes are lost annually in many areas of the world. In order to prevent this, the drying technique is widely used. It allows to lengthen the shelf-life of the fruits. In order to optimize this process, it is necessary to deepen the knowledge on the drying effects on the structure and mobility of the residual water in the fruit. The objective of this paper is to describe the effects of convective drying at different temperatures on the Fast Field Cycling Proton Nuclear Magnetic Resonance (FFC 1H-NMR) relaxation properties, water activity and shrinkage in Keitt mango fruits. The FFC 1H-NMR relaxometry investigations on mango fruits revealed that the convective drying lead not only to a reduction in the overall water content within the mango tissues, but also to a progressive immobilization of the same water, depending on the temperature. From a qualitative and microbiological point of view, the results may indicate that the measure of more immobilised water in the dried fruits can be useful to predict their shelf-life.

The effect of osmotic dehydration before drying on the physicochemical and sensorial characteristics of dried onion slices

The effect of osmotic dehydration before drying on the physicochemical and sensorial characteristics of dried onion slices

A Study and Development of the Control System of Fruit Dehydration Machine by Biomass Energy

This article presents the study and development of the control system of fruit dehydration machine by biomass energy in which manual control system was upgraded to the Auto one. Study results revealed that Auto control system required less operation time for as much as 1.30 hour. By comparing energy consumption of the two systems, the upgraded system required less energy approximately 751.30 baht/month and 9,016.32 baht/year. When the break-even point is taken into consideration, this system upgrade could payback after 3.33 year. The author really hopes that this study can be used as a guideline for those interested or involved in the development fruit dehydration machine.