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

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.

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A Review on Solar Drying of Fish

Journal of Agricultural and Marine Sciences [JAMS] ◽

10.53541/jams.vol26iss2pp1-9 ◽

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.

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Drying and quality performance of dragon blood’s resin (Daemonorops sp.) exposed to solar and oven drying

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/914/1/012058 ◽

2021 ◽

Vol 914 (1) ◽

pp. 012058

Author(s):

G Pasaribu ◽

K Yuniarti ◽

T K Waluyo ◽

E Basri ◽

L Efiyanti

Keyword(s):

Color Change ◽

Quality Parameters ◽

Drying Rate ◽

Solar Drying ◽

Drying Process ◽

Quality Performance ◽

Oven Drying ◽

Drying Techniques ◽

Drying Quality

Abstract Dragon blood’s resin is obtained by extracting the dragon blood’s fruit with organic or non-organic solvents. Following extraction, drying process is usually carried out to dry the wet resin. The drying techniques used is assumed to affect not only the drying performance but also the quality of the dragon blood’s resin, in particular its active ingredient content (dracorhodin). The purpose of this study was to measure and compare the effect of solar and oven drying on the drying performance and quality of dragon blood’s resin. The oven temperature used was 60°C. Both drying techniques were executed until the resin dried which was indicated by color change and its easiness to rupture. The results showed that solar drying of dragon blood required shorter time (210 minutes) with higher drying rate (0.25%/minute) than the oven drying process which need 250 minutes to finish with a drying rate of 0.14%/minute. Except the ash content of solar dried resin, other post-drying quality parameters of dragon blood resin from both drying techniques have met the Indonesia standard for trading purpose (SNI 8663:2018). Further statistical analysis confirmed that the drying techniques applied significantly affected the drying rate and post-drying quality values of dragon blood’s resin.

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Effects of Nocturnal UV-B Irradiation on Growth, Flowering, and Phytochemical Concentration in Leaves of Greenhouse-Grown Red Perilla

Plants ◽

10.3390/plants10061252 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1252

Author(s):

Hideo Yoshida ◽

Tatsuru Nishikawa ◽

Shoko Hikosaka ◽

Eiji Goto

Keyword(s):

Radiation Intensity ◽

Rosmarinic Acid ◽

Color Change ◽

Control Treatment ◽

Leaf Color ◽

Fresh Weight ◽

High Concentration ◽

Fluorescent Lamps ◽

Phenotypic Quality ◽

Intermittent Illumination

In Japan, red perilla leaves are used in the food and coloring industries, as well as in crude medicine. Perilla leaves contain a high concentration of phytochemicals such as perillaldehyde (PA) and rosmarinic acid (RA). The effects of UV-B radiation intensity (0.05–0.2 W m−2, UV-BBE: 0.041–0.083 W m−2), duration (3 or 6 h), and irradiation method (continuous or intermittent) for artificial nocturnal lighting using UV-B fluorescent lamps were evaluated on growth, flowering, and leaf phytochemical concentration in greenhouse-grown perilla. Under continuous UV-B irradiation at 0.1 W m−2 for 3 or 6 h, leaf color changed from red to green and leaf fresh weight decreased, compared with the control treatment. No leaf color change was observed under the 3-h treatment with UV-B radiation at 0.05 W m−2, wherein leaf fresh weight was similar to that of the control. Furthermore, RA concentration under continuous UV-B irradiation at 0.05 W m−2 for 3 h increased two-fold compared to that under control treatment, while PA concentration was not affected by UV-B irradiation. Thus, our data showed that continuous UV-B irradiation at 0.05 W m−2 for 3 h could effectively produce RA-rich perilla leaves without reducing in phenotypic quality or productivity. However, a 6-h intermittent illumination inhibited flowering without altering phytochemical concentration.

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CURVAS DE SECAGEM E AVALIAÇÃO DA ATIVIDADE DE ÁGUA DA BANANA PASSA

Boletim do Centro de Pesquisa de Processamento de Alimentos ◽

10.5380/cep.v22i1.1184 ◽

2004 ◽

Vol 22 (1) ◽

Cited By ~ 3

Author(s):

MILTON CANO-CHAUCA ◽

AFONSO M. RAMOS ◽

PAULO C. STRINGHETA ◽

JOSÉ ANTONIO MARQUES ◽

POLLYANNA IBRAHIM SILVA

Keyword(s):

Experimental Data ◽

Linear Regression ◽

Moisture Content ◽

Water Activity ◽

Linear Regression Analysis ◽

Sorption Isotherms ◽

Exponential Model ◽

Drying Time ◽

Non Linear ◽

Drying Curves

Curvas de secagem de banana passa foram determinadas, utilizando-se três temperaturas do ar de secagem. Os resultados indicaram que para reduzir o teor de umidade do produto até 23,5% foram necessários tempos de secagem de 51, 36 e 30 horas paras as temperaturas de 50, 60 e 70ºC, respectivamente. O modelo exponencial U/Uo = exp(-kt) foi ajustado para os dados experimentais mediante análise de regressão não-linear, encontrandose alto coeficiente de regressão linear. Determinou-se a atividade de água do produto ao longo do processo de secagem para as três temperaturas testadas. Estudou-se a correlação entre a atividade de água e o teor de umidade do produto, determinando-se as isotermas de dessorção da banana passa a 25ºC. Observou-se que a atividade de água diminuiu em função do tempo de secagem e do teor de umidade para as três temperaturas de secagem. Os dados experimentais foram ajustados mediante regressão não-linear ao modelo polinomial e a seguinte equação foi obtida: U = -1844,93 + 7293,53Aa 9515,52Aa2 + 4157,196Aa3. O ajuste mostrou-se satisfatório (R2 > 0,90). DRYING CURVES AND WATER ACTIVITY EVALUATION OF THE BANANA-PASSES Abstract Banana drying curves were determined by utilizing three drying air temperatures. The results indicated that to reduce the moisture content of the product until 23.5% it were necessary drying times of 51, 36 and 30 hours for temperatures of 50, 60 and 70ºC, respectively. The exponential model U/Uo = exp(-kt) was adjusted for the experimental data by means of non linear regression analysis, and a high coefficient of linear regression was found. The water activity of the product was determined throughout the drying process for the three tested temperatures. The correlation between the water activity and moisture content of the product was studied, and the sorption isotherms were determined at 25º C. It was observed that the water activity decreased in function to the drying time and moisture content for the three drying temperatures. The experimental data were adjusted by means of non linear regression to the polynomial model and the following equation was obtained: U = - 1844.93 + 7293.53A a 9515.52 Aa 2 + 4157.196A a 3. The final adjust was satisfactory (R2 > 0.90).

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Combined Transcriptome and Metabolome Integrated Analysis of Acer mandshuricum to Reveal Candidate Genes Involved in Anthocyanin Accumulation

10.21203/rs.3.rs-796758/v1 ◽

2021 ◽

Author(s):

Shikai Zhang ◽

Wang Zhan ◽

Anran Sun ◽

Ying Xie ◽

Zhiming Han ◽

...

Keyword(s):

Regulatory Mechanism ◽

Color Change ◽

Anthocyanin Biosynthesis ◽

Integrated Analysis ◽

Anthocyanin Accumulation ◽

Structural Genes ◽

Leaf Color ◽

Accumulation Pattern ◽

Color Formation ◽

Red Color

Abstract The red color formation of Acer mandshuricum leaves is caused by the accumulation of anthocyanins primarily, but the molecular mechanism researches which underlie anthocyanin biosynthesis in A. mandshuricum were still lacking. Therefore, we combined the transcriptome and metabolome and analyzed the regulatory mechanism and accumulation pattern of anthocyanins in leaf color change periods in three different leaf color states. In our results, 26 anthocyanins were identified. Notably, the metabolite cyanidin 3-O-glucoside was found that significantly correlated with the color formation, was the predominant metabolite in anthocyanin biosynthesis of A. mandshuricum. By the way, two key structural genes ANS (Cluster-20561.86285) and BZ1 (Cluster-20561.99238) in anthocyanidin biosynthesis pathway were significantly up-regulated in RL, suggesting that they might enhance accumulation of cyanidin 3-O-glucoside which is their downstream metabolite, and contributed the red formation of A. mandshuricum leaves. Additionally, most TFs (e.g., MYBs, bZIPs and bHLHs) were detected differentially expressed in three leaf color stages that could participate in anthocyanin accumulation. This study sheds light on the anthocyanin molecular regulation of anthocyanidin bio-synthesis and accumulation underlying the different leaf color change periods in A. mandshuricum, and it could provide basic theory and new insight for the leaf color related genetic improvement of A. mandshuricum.

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Modelagem matemática da desidratação osmo-convectiva da palma forrageira (Opuntia fícus-indica Mill) utilizando soluções mistas

Revista Verde de Agroecologia e Desenvolvimento Sustentável ◽

10.18378/rvads.v10i4.3489 ◽

2015 ◽

Vol 10 (4) ◽

pp. 39

Author(s):

E. T. Silva ◽

E. C. O. Silva ◽

R. P. Gusmão ◽

J. D. Lopes ◽

T. A. S. Gusmão

Keyword(s):

Experimental Data ◽

Water Activity ◽

Osmotic Dehydration ◽

Convective Drying ◽

Human Consumption ◽

Cactus Pear ◽

Opuntia Ficus Indica ◽

Mixed Solutions ◽

Cut Resistance ◽

Best Fit

Objetivou-se nesse estudo avaliar a influência de pré-tratamentos osmóticos utilizando secagem convectiva complementar no processo de perda de água, ganho de sólidos e nos parâmetros de qualidade (cor, atividade de água e textura) de cladódios de palma forrageira. O Cladódio foi submetido à desidratação osmótica utilizando soluções mistas contendo 5% de NaCl e concentrações de sacarose de 50 e 60 °Brix, em diferentes proporções palma/solução (1:1, 1:4 e 1:10) a 40°C. Posteriormente foi realizada secagem convectiva a 50 e 60 °C. Foram utilizados, para ajuste aos dados experimentais da secagem, os modelos matemáticos de Page, Henderson & Pabis, Cavancanti Mata, Exponencial de Dois Termos e Midilli. O cladódio de palma in natura e desidratado foi caracterizado quanto aos parâmetros de cor, atividade de água e textura. O aumento da perda de massa foi proporcional ao aumento da proporção cladódio/solução utilizada na desidratação osmótica e o ganho de sólidos foi maior para a concentração de 50 °Brix. O modelo matemático de Midilli foi o que melhor se ajustou aos dados experimentais. Os parâmetros de cor, atividade de água e textura foram modificados pelas condições de desidratação osmótica e de secagem as quais o cladódio de palma foi submetido. O cladódio desidratado a 50 °C apresentou melhor preservação da cor, maior resistência ao corte e menor atividade de água. Mathematical modeling of osmo-convective dehydration of the cactus pear (Opuntia ficus-indica Mill) using mixed solutionsAbstract: The objective of this study was to evaluate the influence of osmotic pre-treatments with complementary convective drying in the water loss process and solids gain of cactus pear cladodes, to obtain palm for human consumption. The cladode was subjected to osmotic dehydration using mixed solutions containing 5% NaCl and sugar concentrations of 50 and 60 °Brix in different proportions palm/solution (1:1, 1:4 and 1:10) at 40 °C. Subsequently convective drying was performed at 50 and 60 °C. Were used to fit to the experimental data of drying, the mathematical models for Page, Henderson & Pabis, Cavancanti Mata, Exponential of Two Terms and Midilli. The spineless cactus in natura and dehydrated was characterized as the parameters: color, water activity and texture. The study noted that the increased of weight mass was proportional to the increased of proportion cladode/solution used in osmotic dehydration and the solids gain was higher for concentration of 50 °Brix. The Midilli mathematical model was the best fit to the experimental data. The parameters of color, water activity and texture were modified by the conditions of osmotic dehydration and drying which spineless cactus cladodes was submitted. The cactus cladode dehydrated at 50 °C presented better preservation of the color, increased cut resistance and lowest water activity.

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Propiedades físicas de naranja agria cocristalizada: efecto del pH, sólidos solubles y zumo adicionado

Agronomía Mesoamericana ◽

10.15517/ma.v28i2.23833 ◽

2017 ◽

Vol 28 (2) ◽

pp. 427

Author(s):

Ricardo David Andrade Pizarro ◽

Kevin Blanquicett Gónzalez ◽

Rafael Rangel terraza

Keyword(s):

Water Activity ◽

Orange Juice ◽

Solid Material ◽

Soluble Solids ◽

High Humidity ◽

High Solubility ◽

Bitter Orange ◽

Moisture Contents ◽

Particulate Solid ◽

Juice Concentrate

The aim of this study was to evaluate the conditions of co-crystallization of bitter orange juice with sucrose on the physicochemical properties of the product. Bitter orange juice was obtained with a mechanical juicer and concentrated on a rotary evaporator. Sucrose syrup 70 oBrix was subjected to heating and stirring of 1000 rpm, until a white color (118 °C) was observed. Bitter orange juice was added to the syrup, and the mixture was subjected to constant stirring of 600 rpm, to observe the formation of a particulate solid material. The co-crystals were dried, grinded and sieved. A dry co-crystal was determined: moisture, bulk density, solubility, water activity and repose angle. High proportion of bitter orange juice added (20%) and low content of soluble solids (50 °Brix) produced co-crystals with low moisture content (2.59%), water activity (0.52) and solubility time (69.4 s). High pH (4.5) of bitter orange juice concentrate produced co-crystals with low moisture contents (1.96%). The co-crystals of bitter orange juice showed good reconstitution characteristics (high solubility); however, these had high humidity (2.5 to 4.5%) and water activity (0.508 to 0.798).

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Small Scale Investigation of the Potential of Solar Drying of Water Hyacinth (Eichhornia Crassipes) as A Control Measure in Makurdi

NIGERIAN ANNALS OF PURE AND APPLIED SCIENCES ◽

10.46912/napas.18 ◽

2015 ◽

Vol 6 ◽

pp. 129-138

Author(s):

A O Edeoja ◽

A O Owolabi

Keyword(s):

Water Hyacinth ◽

Mixed Mode ◽

Eichhornia Crassipes ◽

Control Measure ◽

Small Scale ◽

Drying Rate ◽

Aquatic Weed ◽

Solar Drying ◽

Water Weed

Water hyacinth is the world's worst water weed that is responsible for many environmental and economical problems. Nigerian fresh waters have been infested with this aquatic weed. In this work, a Natural Convection Mixed Mode Solar Dryer for drying water hyacinth to about 10% of its moisture content was constructed and tested as a component of controlling its infestation of the River Benue. The performance of the dryer was compared with the traditional open–air sun drying as the control for drying water hyacinth in Makurdi, Benue State Nigeria. The water hyacinth was dried for 8 hours each day for 4 days. 500g of water hyacinth on wet basis was dehydrated by about 437g on dry basis in 20 hours in the dryer while the control required 32 hours. The dryer was found to be technically more suitable for drying water hyacinth both in terms of the drying rate and quality of the dried product.

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

International Journal of Innovative Research and Scientific Studies ◽

10.53894/ijirss.v4i2.55 ◽

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.

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Microbial Decontamination of Fresh Produce (Strawberry) Using Washing Solutions

Journal of Food Research ◽

10.5539/jfr.v4n3p128 ◽

2015 ◽

Vol 4 (3) ◽

pp. 128 ◽

Cited By ~ 3

Author(s):

Naresh Shahi ◽

ByungJin Min ◽

Eunice A. Bonsi

Keyword(s):

Color Change ◽

Fresh Produce ◽

Inhibitory Effect ◽

Lemon Juice ◽

Water Control ◽

Significant Difference ◽

Total Color Change ◽

Origanum Oil ◽

Preliminary Study ◽

White Vinegar

This study was carried out to determine the effect of natural antimicrobial washing solutions against microbial growths on fresh produce specifically strawberries. Selected washing solutions used for strawberry washing, and treatments were sterile water (control), white vinegar (VI), crude lemon juice extract (LE), VI+Origanum oil (VIO), LE+Origanum oil (LEO), and VI+LE+Origanum oil (VILEO). From the preliminary study of antimicrobial activity of washing solutions in aqueous model system tested at 2, 5, 10, 15, 20 and 25 min against S. Typhimurium, washing time was determined as 5 min to be used for this study. After the washing, strawberries were stored at 4 °C for 5 days. Results showed that all natural washing solutions exhibited inhibitory effect against total aerobic bacteria, yeast and mold. On day 5, compared to the control, all washing solutions significantly reduced S. Typhimurium by 2.7 Log CFU/g (P<0.05). Color results showed that samples color were slightly changed by washing with VIO and VILEO. However, there was no significant difference in total color change on strawberries compared to the control (P>0.05). Based on the results, it is indicated that the combination of vinegar with crude lemon juice extract and essential oil might be suitable as natural sanitizer for decontamination of fresh produce.

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