scholarly journals A Review on Solar Drying of Fish

2021 ◽  
Vol 26 (2) ◽  
pp. 1-9
Author(s):  
Abdulrahim Al-Ismaili
Keyword(s):  
Water Activity ◽  
Microbiological Quality ◽  
Plate Count ◽  
Drying Rate ◽  
Solar Drying ◽  
Drying Time ◽  
Fish Products ◽  
Sun Drying ◽  
Drying Techniques ◽  
Dried Fish

Oman is one of the larger fish producers in the region. Due to high perishable rate of fish products, many preservation techniques were used such as smoking, drying, chilling, brining and freezing. Solar drying is the most popular technique due to its simplicity and low cost compared to other techniques. Objective. This study aims to review the different types of solar drying techniques and highlight the quality measures of solar dried fish. Review findings. Solar drying techniques can be divided into three types; open-sun drying, direct and indirect solar drying. The open-sun drying is the most adoptable method because it is the cheapest preservation technique. However, this technique has several drawbacks such as the uncertainty of weather, large implementation area, time-consuming, poor drying rate, high labour costs, attacking by insects, microorganism and birds, and mixing with dust and foreign materials. Solar dryers, on the other hand, overcome most of the drawbacks associated with open-sun drying. They have shorter drying time and higher drying rate, and at the same time they enhance the physical properties of dried fish. For better understanding of the drying processes many regression models were used and the exponential model was found to be the best fitted model describing the drying behaviour. The fish have very good nutritional value due to higher amount of proteins, lipids and ash contents with comparison to fresh fish. For higher shelf life fish has to meet certain characteristics with respect to pH, water activity, microbial load, total volatile base nitrogen (TVB-N), trimethylamine nitrogen (TMA-N) and enzymatic autolysis. For a very good quality, the pH must be ranging from 6.0-6.9 and the water activity must be lower than 0.7. The TVB-N and TMA-N are indicators of spoilage and their upper acceptable limits are 10-15 mg/100g and 35-40 mg/100g, respectively. Total plate count (TPC) and total fungal count (TFC) are two attributes used to assess the microbiological quality of fish products. The autolysis changes in the fish lead to spoilage as a result of the production of biogenic amines and microbial growth. Conclusions. Studying the health aspect of dried fish is very important for the human body to obtain a greater proportion of proteins and important substances away from the harmful chemicals that may appear in traditional draying technique.

scholarly journals Effects of Blanching and Natural Convection Solar Drying on Quality Characteristics of Red Pepper (Capsicum annuum L.)

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
James Owusu-Kwarteng ◽  
Francis K. K. Kori ◽  
Fortune Akabanda
Keyword(s):  
Natural Convection ◽  
Quality Characteristics ◽  
Red Pepper ◽  
Plain Water ◽  
Drying Methods ◽  
Solar Drying ◽  
Drying Time ◽  
Sun Drying ◽  
Overall Acceptability ◽  
Solar Dryer

The objective of this work was to determine the effects of blanching and two drying methods, open-sun drying and natural convection solar drying, on the quality characteristics of red pepper. A 2 × 3 factorial design with experimental factors as 2 drying methods (open-sun drying and use of solar dryer) and 3 levels of pepper blanching (unblanched, blanched in plain water, and blanched in 2% NaCl) was conducted. Dried pepper samples were analysed for chemical composition, microbial load, and consumer sensory acceptability. Blanching of pepper in 2% NaCl solution followed by drying in a natural convection solar dryer reduced drying time by 15 hours. Similarly, a combination of blanching and drying in the solar dryer improved microbial quality of dried pepper. However, blanching and drying processes resulted in reduction in nutrients such as vitamin C and minerals content of pepper. Blanching followed by drying in natural convection solar dryer had the highest consumer acceptability scores for colour and overall acceptability, while texture and aroma were not significantly (p>0.05) affected by the different treatments. Therefore, natural convection solar dryer can be used to dry pepper with acceptable microbial and sensory qualities, as an alternative to open-sun drying.

scholarly journals Comparative study of physical, chemical, microbiological and sensory aspects of some sun dried fishes in Bangladesh

2017 ◽  
Vol 4 (8) ◽  
pp. 323-331 ◽  
Author(s):  
Bhaskar Chandra Majumdar ◽  
Faria Afrin ◽  
Md. Golam Rasul ◽  
Murshida Khan ◽  
A. K. M. Azad Shah
Keyword(s):  
Acid Value ◽  
Plate Count ◽  
Fish Products ◽  
Physical Chemical ◽  
Physico Chemical ◽  
Wallago Attu ◽  
Acceptable Quality ◽  
Dried Fish ◽  
Aerobic Plate Count ◽  
Glossogobius Giuris

An investigation was carried out to compare the physical, chemical, microbiological and sensory properties of three freshwater dried fish products of Wallago attu Bloch & Schneider, 1801 (Siluriformes: Siluridae), Channa striatus (Bloch, 1793) (Perciformes: Channidae) and Glossogobius giuris (F. Hamilton, 1822) (Perciformes: Gobiidae). The traditionally sun dried fishes were collected from Kawran Bazar Fish Market, Dhaka, Bangladesh. Results showed that the water reconstitution properties varied among the dried fishes where maximum rehydration was observed in the C. striatus at room temperature, 40 oC and 60 oC. Moisture content of W. attu, C. striatus and G. giuris were 22.70% +/- 0.45%, 18.75% +/- 0.58% and 21.93% +/- 0.54%, respectively; the protein content were 61.85% +/- 0.99%, 66.44% +/- 1.02% and 62.83% +/- 0.87%, respectively; the lipid content were 6.21% +/- 0.93%, 6.81% +/- 0.72% and 5.98% +/- 0.55%, respectively, and the ash content were 6.79% +/- 1.11%, 6.49% +/- 1.29% and 7.83% +/- 0.98%, respectively. Peroxide value, acid value, pH, TVB N value and aerobic plate count were found to be highest in W. attu followed by G. giuris and C. striatus. Results of this study revealed that traditionally sun dried fish products were acceptable quality in terms of physico-chemical, microbiological and sensory aspects.

scholarly journals Thin-layer mathematical modeling of apple slices drying, using open sun and cabinet solar drying methods

2021 ◽  
Vol 4 (2) ◽  
pp. 43-52
Author(s):  
Abdul Wasim Noori ◽  
Mohammad Jafar Royen ◽  
Juma Haydary
Keyword(s):  
Thin Layer ◽  
Mathematical Models ◽  
Water Activity ◽  
Model Fitting ◽  
Coefficient Of Determination ◽  
Drying Methods ◽  
Solar Drying ◽  
Drying Time ◽  
Climate Conditions ◽  
Thin Layer Drying

This paper aims to investigate the effect of climate conditions such as ambient temperature, humidity, pressure, sun radiation and pollution on sliced apples quality and drying time which are dried in an indirect forced cabinet solar drying (IFCSD) and open sun drying (OSD) systems. Both experiments were implemented at same place (Kabul, Afghanistan) and time. The IFCSD yield for saving time is 42.8 % which is more effective than drying in the OSD system. Simultaneously with the decreasing of sliced apple weight from 512.9 g down to 73.9 g, the water activity decreased from 0.955 down to 0.355 in the IFCSD system. For OSD system, the sample weight decreased from 512.6 g down to 78.4 g and its water activity from 0.955 down to 0.411. On the experiment day the average sun radiation was 571 w/m2 . The pressure drop between inlet and outlet of the dryer was 0.1 kPa. Different thin-layer mathematical models were investigated to identify the best model fitting the experimental data. The mathematical models’ performances were investigated by comparing the coefficient of determination (R 2 ), reduced chi-square (X2 ) and root mean square error (RMSE) coefficients. From all 11 applied thin-layer drying models the Page, Approximation diffusion, Verma et al and Midilli and Kacuk models are more fitted to our data.

scholarly journals Drying of MalaysianCapsicum annuumL. (Red Chili) Dried by Open and Solar Drying

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ahmad Fudholi ◽  
Mohd Yusof Othman ◽  
Mohd Hafidz Ruslan ◽  
Kamaruzzaman Sopian
Keyword(s):  
Root Mean Square ◽  
Coefficient Of Determination ◽  
Mean Bias Error ◽  
Bias Error ◽  
Solar Drying ◽  
Mean Square ◽  
Drying Time ◽  
Sun Drying ◽  
65 H ◽  
Mean Square Errors

This study evaluated the performance of solar drying in the Malaysian red chili (Capsicum annuumL.). Red chilies were dried down from approximately 80% (wb) to 10% (wb) moisture content within 33 h. The drying process was conducted during the day, and it was compared with 65 h of open sun drying. Solar drying yielded a 49% saving in drying time compared with open sun drying. At the average solar radiation of 420 W/m2and air flow rate of 0.07 kg/s, the collector, drying system, and pickup demonstrated efficiency rates of approximately 28%, 13%, and 45%, respectively. Evaporative capacity ranged from 0.13 to 2.36 kg/h, with an average of 0.97 kg/h. The specific moisture extraction rate (SMER) of 0.19 kg/kWh was obtained. Moreover, the drying kinetics ofC. annuumL. were investigated. A nonlinear regression procedure was used to fit three drying models. These models were compared with experimental data on red chilies dried by open sun drying and those dried by solar drying. The fit quality of the models was evaluated using their coefficient of determination (R2), mean bias error, and root-mean-square error values. The Page model resulted in the highestR2and the lowest mean bias and root-mean-square errors.

scholarly journals Kinetics, modeling and colorimetry of celery leaves dehydration by direct and mixed solar drying

2021 ◽  
pp. 22-28
Author(s):  
Beatriz Castillo-Téllez ◽  
Margarita Castillo-Téllez ◽  
Gerardo Alberto Mejía-Pérez ◽  
Carlos Jesahel Vega Gómez
Keyword(s):  
Experimental Data ◽  
Water Activity ◽  
Color Change ◽  
Drying Rate ◽  
Solar Drying ◽  
Leaf Color ◽  
Moisture Contents ◽  
Quality Product ◽  
Total Color Change ◽  
Medicinal Properties

In celery, leaves, roots, and fruit contain a high value in medicinal properties and are used to prepare syrups, tinctures, infusions, or oils; however, its leaves are commonly discarded, wasting their nutritional and medicinal content. The dehydration of these leaves is a conservation option, increasing their shelf life. This study analyzes direct and mixed solar drying (SD and SM) kinetics and their effect on celery leaves. The moisture contents, drying rate, water activity, and colorimetry were obtained. Moreover, the fitting of experimental data to the mathematical models proposed in the literature. The moisture content stabilized at 150 min in the SM at the shortest time with a maximum drying rate of 0.1179 g∙water/g∙ dm∙min. The initial and final water activity was 0.98 and 0.412 in the SM and 0.403 in the SD. The SD better conserved the leaf color, with a total color change (ΔE) of 2.56, while the value obtained with the SM was 5.42. The experimental results of both technologies were better adjusted to the model Two exponential terms with an R² of 0.999. The results show that the solar drying of the celery leaves is feasible, and a quality product is obtained sustainably.

scholarly journals Effect of Drying Methods on the Physico-chemical Characteristics and Antioxidant Capacity of Taro, Sweetpotato, Stevia and Malunggay Leaves

2017 ◽  
pp. 88-99
Author(s):  
Inish Chris Mesias ◽  
Julie Tan ◽  
Daniel Leslie Tan ◽  
Benjamin L. Cinto
Keyword(s):  
Antioxidant Capacity ◽  
Bulk Density ◽  
Water Activity ◽  
Enzymatic Browning ◽  
Chemical Characteristics ◽  
Drying Methods ◽  
Solar Drying ◽  
Rehydration Ratio ◽  
Sun Drying ◽  
Physico Chemical

Fresh leaves are sensitive to high temperature so that appropriate drying method should be selected to dry leaves. This study aimed to determine the effect of drying methods on the physico-chemical characteristics and antioxidant capacity of taro (Colocasia esculenta), sweetpotato (Ipomea batatas), stevia (Stevia rebaudiana), and malunggay (Moringa oleifera) leaves. Fresh, healthy and mature leaves of taro, sweetpotato, stevia, and malunggay were subjected to solar drying, mechanical drying, and sun drying. The parameters evaluated in this study included moisture content, rehydration ratio, bulk density, water activity, total chlorophyll, antioxidant capacity, and non-enzymatic browning. Results showed that solar drying obtained the highest moisture removal capacity, rehydration ratio and water activity reduction while sun drying had the least. However, it was also with solar drying that the degree of non-enzymatic browning was the highest. Minimum bulk density was attained using solar and mechanical drying. In terms of chlorophyll content, mechanical drying had the highest. No apparent difference at p<0.05 between solar and sun drying methods was observed in terms of their effects on chlorophyll retention and antioxidant capacity. Variable effects of the different drying methods include little or no change, significant declines or enhancement of the leaves' physico-chemical and antioxidant attributes.

scholarly journals Elaboración Sostenible de Harina de Chile Jalapeño (Capsicum annuum L.) Mediante Secado Solar Tecnificado

2018 ◽  
Vol 14 (30) ◽  
pp. 15
Author(s):  
Gustavo Antonio Pech-González ◽  
Érika Guadalupe Ceballos-Falcón ◽  
Nicolás González-Cortés ◽  
Román Jiménez-Vera
Keyword(s):  
Capsicum Annuum ◽  
Microbiological Quality ◽  
Microbial Load ◽  
Human Consumption ◽  
Solar Drying ◽  
Drying Time ◽  
Capsicum Annuum L ◽  
Zinc Sheet ◽  
Protected Natural Areas

Jalapeño pepper (Capsicum annuum L.) is a crop in protected natural areas of Tabasco, Mexico. Solar drying is a non-polluting energy that is applicable to food processing. This paper focuses on comparing the microbiological quality of dehydrated jalapeño peppers by means of three methods: direct solar (SD), electric stove (EE), and experimental solar dryer (SSE). SD drying was carried out in zinc sheet by conduction. The drying in EE was at a temperature of 70°C and the SSE has an internal temperature of 43 ° C ± 2 ° C. The dehydrated chiles were crushed in artisanal equipment, and the flour was stored in tightly closed glass containers at room temperature (22-28 ° C). The drying time was lower in the EE (7 h), followed by the SSE (8 h) and the SD (18 h). With EE, the lowest microbial load was obtained and with SD, the highest was obtained. The flour obtained with the SSE presented a concentration of microorganisms within the Mexican norms: total coliforms (25 CFU / g), Staphylococcus aureus (62 CFU / g), and aerobic mesophiles (57 CFU / g). Although the drying time and the microbial load were lower with the EE, the SSE allowed the elaboration of jalapeño pepper flour with the microbiological quality required for human consumption. Technified solar drying is a sustainable alternative for the dehydration of foods in tropical countries.

Kinetic and Thermodynamic Characteristics of Seaweed Dried in the Convective Air Drier

2010 ◽  
Vol 6 (5) ◽  
Author(s):  
Rosalam Sarbatly ◽  
Tracy Wong ◽  
Awang Bono ◽  
Duduku Krishnaiah
Keyword(s):  
Specific Heat ◽  
Air Temperature ◽  
Flow Rate ◽  
Thermodynamic Characteristics ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Time ◽  
Sun Drying ◽  
Drying Efficiency

This study reveals the drying kinetics, specific heat and enthalpy of seaweed dried in the convective air drier. Comparison between convective hot air and sun drying process was also studied. At 50°C air temperature with 23.45 percent relative humidity and 1.55 ms-1air flow rate, it has been found that the moisture removal required 4 hours to reach moisture content of 19.66 percent wet basis with its drying rate at 0.28 x 10-3 kg water h-1. The data of drying rate showed that the drying process took place in the falling rate period. The specific heat and initial enthalpy were found to be 1.3842 kJkg-1°C-1 and 1672.69 kJkg-1, respectively. It was observed that the drying kinetics, specific heat, and enthalpy values vary significantly as functions of air temperature which seem to have more effect when compared to air flow rate and seaweed loading. Hence, the best method for seaweed drying was to use convective air system rather than sun drying because it required less drying time and has better drying efficiency.

scholarly journals Modeling of mass transfer processes during dehydration of air-dried fish

2021 ◽  
Vol 83 (1) ◽  
pp. 55-61
Author(s):  
M. A. Ershov ◽  
A. M. Ershov ◽  
E. V. Lyzhin ◽  
V. A. Grohovskiy ◽  
Z. G. Dimova
Keyword(s):  
Mass Transfer ◽  
Diffusion Coefficients ◽  
Food Products ◽  
Production Costs ◽  
Added Value ◽  
Drying Time ◽  
Fish Products ◽  
Murmansk Region ◽  
Dried Fish ◽  
Dehydration Processes

The study addresses the problems of the Fisheries industry development in the Murmansk region. It has been acknowledged that the percentage of the frozen fish in the output of hydrobionts food products is about 90 %. The focus areas for the Russian Fisheries industry are the increasing share of products with high added value and the development of the domestic consumer market of fishery products. It has been found that the air-dried and dried fish products with defined organoleptic properties is traditionally in strong demand with the population. However, the range of air-dried and dried fish products available for the consumers is rather limited. Moreover, there is a very small part of air-dried and dried fish in the total volume of hydrobionts food products. It is possible to increase the efficiency of air-dried and dried fish production by using the scientific-based process solutions, which allow to reduce the production costs and improve the consumer properties of the finished products. This paper presents the aspects of generalization of the dehydration processes in the production of dried, air-dried and smoked fish. A link between the initial, critical moisture content of fish and the potential conductivity of mass transfer coefficients has been established. A mathematical relation for calculating the duration and modeling the kinetics of drying processes in production of dried and air-dried fish has been determined. The equations for calculating the water diffusion coefficients in the critical points of the kinetics curve have been obtained. The combined use of the received patterns allows to model the dehydration processes when producing the air-dried and dried fish products, calculate the drying time, determine the moisture diffusion coefficients and build dependencies of water distribution in the thickness of the processed object.

scholarly journals Design and Analysis of a Novel Drying Chamber in Indirect Forced Convection Solar Drying

2020 ◽  
Vol 9 (9s) ◽  
pp. 11-16
Keyword(s):  
Energy Efficiency ◽  
Forced Convection ◽  
Solar Collector ◽  
Ambient Air ◽  
Drying Rate ◽  
Solar Drying ◽  
Drying Time ◽  
Hot Air ◽  
Drying Chamber ◽  
Effective Distribution

Long drying time and less control on drying parameters in natural convection drying give way to forced convection indirect solar drying. In forced convection drying, an external blower supplies ambient air into the solar collector. The incoming air gets heated inside the collector and this air then flows into the drying chamber where the product to be dried is kept. The hot air absorbs the moisture from the raw crops and exits through the chimney. Along with the temperature and humidity of incoming air, its distribution inside the drying chamber is also important in the process of drying. The drying rate and quality can be improved if these parameters are under control in forced convection solar drying. In this paper, design and analysis of a novel drying chamber are presented to improve the performance and energy efficiency of solar drying with effective distribution of air inside the chamber. The variation of velocity with respect to different positions inside the drying chamber is also studied numerically.

Sign in / Sign up

Export Citation Format

Share Document