The Influence of Drying Temperatures and Methods on the Drying Characteristics of ‘IkanBakar’ Paste

Drying is one of the popular preservation methods in food products. This work was done to investigate the influence of the drying temperatures and methods on the drying characteristics of ‘ikanbakar’ paste. The ‘ikanbakar’ paste was dried by using oven drying and vacuum drying methods at temperatures of 50°C, 60°C and 70°C. The drying rate was estimated from the moisture content and drying time data. The drying curve showed the falling rate period as the drying rate decreased with increasing time. For colour analysis of the paste, the L* values from the oven drying method were lower than those from the vacuum drying method, ranging from 7.4210 to 7.2752. This showed that the colour of paste from oven drying was darker than vacuum drying. The mathematical models used to describe the drying curve of ‘ikanbakar’ paste were Lewis, Page, Two-term, and Midilliet. al. model. The performance of these models was evaluated by comparing their root mean square error (RSME) and chi-square (X²) values, and it was found that the most suitable model was the Two-term model. There were insignificant differences between the effective moisture diffusivity (Deff) values for the ‘ikanbakar’ paste in both drying methods.

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Kinetika Pengeringan Cabai dengan Perlakuan Blansing Suhu Rendah-Waktu Lama

AGRITEKNO Jurnal Teknologi Pertanian ◽

10.30598/jagritekno.2021.10.1.24 ◽

2021 ◽

Vol 10 (1) ◽

pp. 24-35

Author(s):

Andi Muhammad Irfan ◽

Nunik Lestari ◽

Arimansyah Arimansyah ◽

A Ramli Rasyid

Keyword(s):

High Temperature ◽

Low Temperature ◽

Drying Rate ◽

Suitable Model ◽

Drying Time ◽

Drying Characteristics ◽

High Temperature Short Time ◽

Long Time ◽

Short Time ◽

Kinetics Of

This study was aimed to determine the drying kinetics of chilies that have been pretreated with low temperature long time (LTLT) blanching. Drying chilies with LTLT blanching pretreatment at 60, 70, and 80 oC for 20 minutes was assigned as treatment in this research. Drying chillies with high temperature short time (HTST) blanching pretreatment, without blanching pretreatment in the dryer, and without blanching pretreatment in direct sunlight were also studied as the comparison. The results showed that chilies treated with blanching pretreatment, both LTLT and HTST, have a faster drying rate and achieve the target moisture content faster than chilies that were not blanched. The color of dried chilies that were dried in a dryer was also better than dried chilies that were dried in the sun. Of all the blanching treatments, chilies with LTLT blanching pretreatment at 80 oC for 20 minutes had the fastest drying rate, a drying time of 34 hours, and the attractive dried chilli color. The evaluation results also showed that the Page model was the most suitable model to describe the drying characteristics of chilies with LTLT pretreatment blanching, with R2 ranging from 0.9913-0.9935, X2 ranging from 0.0005-0.0009, and RSME ranging from 0.0221-0.0293. Keywords: Chili; blanching; color; drying; mathematical model ABSTRAK Penelitian ini bertujuan untuk mengetahui kinetika pengeringan cabai yang diberi perlakuan awal low temperature long time (LTLT) blanching atau blansing pada suhu rendah dalam waktu yang relatif lama. Perlakuan pada penelitian ini yaitu pengeringan cabai dengan blansing metode LTLT pada suhu 60o, 70o, dan 80oC selama 20 menit. Sebagai pembanding, dilakukan juga pengeringan dengan perlakuan awal metode high temperature short time (HTST) blanching, pengeringan cabai tanpa perlakuan awal blansing di dalam alat pengering, serta pengeringan cabai tanpa perlakuan awal blansing di bawah sinar matahari secara langsung. Hasil penelitian menunjukkan bahwa cabai dengan perlakuan awal blansing, baik blansing metode LTLT maupun HTST, memiliki laju pengeringan yang lebih tinggi sehingga lebih cepat mencapai kadar air target dibandingkan dengan cabai tanpa perlakuan blansing. Warna cabai kering yang dihasilkan pada alat pengering juga lebih baik dari cabai kering yang dikeringkan langsung di bawah sinar matahari. Dari seluruh perlakuan yang melibatkan proses blansing, cabai dengan blansing metode LTLT pada suhu 80oC selama 20 menit merupakan perlakuan dengan laju pengeringan tercepat, dengan waktu pengeringan selama 34 jam, dan warna produk cabai kering yang menarik. Hasil evaluasi juga menunjukkan bahwa model Page adalah model yang paling sesuai untuk menggambarkan karakteristik pengeringan cabai dengan perlakuan awal blansing metode LTLT, dengan R2 berkisar antara 0.9913-0.9935, X2 berkisar antara 0.0005-0.0009, dan RSME berkisar antara 0.0221-0.0293. Kata kunci: Blansing; cabai; model matematika; pengeringan; warna

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Comparative kinetic analysis of convective and vacuum dried Opuntia ficus-indica (L.) Mill. cladodes

Research in Agricultural Engineering ◽

10.17221/18/2018-rae ◽

2019 ◽

Vol 65 (No. 1) ◽

pp. 1-6

Author(s):

Anirban Dey ◽

Somya Singhal ◽

Prasad Rasane ◽

Sawinder Kaur ◽

Navneet Kaur ◽

...

Keyword(s):

Convective Drying ◽

Coefficient Of Determination ◽

Vacuum Drying ◽

Drying Methods ◽

Drying Method ◽

Statistical Parameters ◽

Drying Time ◽

Opuntia Ficus Indica ◽

Thin Layer Drying ◽

Drying Behavior

Opuntia ficus-indica (Linnaeus) Miller more usually known as fodder palm or nopal belongs to family Cactaceae. In the present study, the drying behavior of the O. ficus-indica cladodes was observed. The study concentrates on comparatively studying two types of commercial drying methods viz., forced convective drying (tray drying) and vacuum drying to dry nopal cladodes at three different temperatures viz. 40, 50 and 60°C. The equilibrium moisture contents for forced convective drying was achieved at 540–720 min and for that of vacuum drying at 600–840 min. Three mathematical drying models for thin layer drying viz. Page, Lewis and Henderson-Pabis model were evaluated for both convective drying and vacuum drying. Statistical parameters such as the coefficient of determination (R<sup>2</sup>), root mean square error and reduced χ<sup>2</sup> were used to fit the models. Page model was found to be satisfactory for both forced convective and vacuum drying of the nopal cladodes at 40 and 50°C respectively. Among these, two drying methods, forced convective drying method was found to be more suitable than the vacuum drying method for nopal cladodes on the basis of drying time and statistical parameters.

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Sun Drying and Far-Infrared Drying Characteristics of Lily

ASME 2021 Heat Transfer Summer Conference ◽

10.1115/ht2021-63541 ◽

2021 ◽

Author(s):

Pei Yang ◽

Dan Huang ◽

Sisi Lv ◽

Ruiqi Wang ◽

S. A. Sherif ◽

...

Keyword(s):

Far Infrared ◽

Drying Rate ◽

Drying Method ◽

Drying Time ◽

Drying Characteristics ◽

Drying Temperature ◽

Nutrient Contents ◽

Infrared Drying ◽

Sun Drying ◽

Pretreatment Time

Abstract The sun drying and far-infrared drying characteristics of lily were experimentally investigated. Fresh lily was blanched and treated with boiling water at 100 °C before drying. The effects of blanching time, drying method and drying temperature on drying rate, nutrient contents (total phenol, total flavonoid and starch contents), hardness and color were analyzed. The results showed that fresh lily without blanching pretreatment had deep browning color, wrinkled skin and long drying time under any drying temperature and drying method. However, the drying rate of samples with blanching pretreatment was significantly increased and the drying time was shortened. The drying rate of solar drying was much lower than that of infrared drying, however the drying quality is better. With the increase of blanching time, the browning degree and the nutrient contents under both drying methods were reduced, while the foaming rate was increased. The hardness after solar drying was moderate, while the hardness of far-infrared drying gradually increased with the increase of drying temperature. The blanching time of 4–6 min was the ideal pretreatment time. Under this pretreatment time, a sample with fair color and moderate hardness and nutrient contents can be obtained under the far-infrared drying temperature of 60–90 °C. The far-infrared drying was more suitable than the sun drying and the most suitable drying process was as follows: fresh lilies were blanched at 100 °C for 5 minutes, and then dried at 70°C for 7.5 hours.

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Evaluation of Innovative Dried Purée from Jerusalem Artichoke—In Vitro Studies of Its Physicochemical and Health-Promoting Properties

Molecules ◽

10.3390/molecules26092644 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2644

Author(s):

Jan Oszmiański ◽

Sabina Lachowicz ◽

Paulina Nowicka ◽

Paweł Rubiński ◽

Tomasz Cebulak

Keyword(s):

Freeze Drying ◽

Jerusalem Artichoke ◽

Polyphenolic Compounds ◽

Raw Material ◽

Vacuum Drying ◽

Drying Methods ◽

Drying Method ◽

Activity Inhibition ◽

Health Promoting

The present study aimed to evaluate the effect of Jerusalem artichoke processing methods and drying methods (freeze drying, sublimation drying, vacuum drying) on the basic physicochemical parameters, profiles and contents of sugars and polyphenolic compounds, and health-promoting properties (antioxidant activity, inhibition of the activities of α-amylase, α-glucosidase, and pancreatic lipase) of the produced purée. A total of 25 polyphenolic compounds belonging to hydroxycinnamic phenolic acids (LC-PDA-MS-QTof) were detected in Jerusalem artichoke purée. Their average content in the raw material was at 820 mg/100 g dm (UPLC-PDA-FL) and was 2.7 times higher than in the cooked material. The chemical composition and the health-promoting value of the purées were affected by the drying method, with the most beneficial values of the evaluated parameters obtained upon freeze drying. Vacuum drying could offer an alternative to freeze drying, as both methods ensured relatively comparable values of the assessed parameters.

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Influence of Pear Variety and Drying Methods on the Quality of Dried Fruit

Molecules ◽

10.3390/molecules25215146 ◽

2020 ◽

Vol 25 (21) ◽

pp. 5146

Author(s):

Agata Marzec ◽

Hanna Kowalska ◽

Jolanta Kowalska ◽

Ewa Domian ◽

Andrzej Lenart

Keyword(s):

Principal Component ◽

Acoustic Method ◽

Drying Methods ◽

Drying Method ◽

Drying Time ◽

Good Taste ◽

Dried Fruit ◽

Breaking Work ◽

Alexander Lucas

In this study, the impacts of two different pear cultivars, “Conference” and “Alexander Lucas”, on the kinetics and the final quality of samples dried by convection (CD) and microwave-convection (MCD) methods, were investigated. The quality of dried material was evaluated by the analysis of water activity, porosity, color, acoustic emission (AE) and mechanical and sensory properties. The required drying time to obtain 0.2 kg H2O/kg dry solid (d.s.) was longer for “Conference” than “Alexander Lucas” and was 20 min by CD and 5 min by MCD. The pear cultivar, in conjunction with the drying method (CD or MCD), affected the number of AE events and the work of breaking. The CD pear of the “Conference” cultivar was characterized by higher force, higher breaking work and stronger AE relative to the CD pear of the “Alexander Lucas” cultivar. There were no differences in taste or overall quality, but the hardness was higher for the CD “Conference” pear. A principal component analysis showed that panelists preferred dried fruit with good taste and overall quality but lower hardness. A positive correlation was found between the number of acoustic events and sensory hardness; thus, an acoustic method can be useful for effectively evaluating the texture of dried pears. These results show that the dried pear slices that generated fewer AE events upon breaking were perceived as better by the panelists.

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Effect of drying methods on the nutritional content and In- vitro Antioxidant capacity of Chenopodium album L. and Spinacia oleracea L.

Research Journal of Pharmacy and Technology ◽

10.52711/0974-360x.2021.00757 ◽

2021 ◽

pp. 4361-4366

Author(s):

Sonia Singh ◽

Neetu Agrawal

Keyword(s):

Spinacia Oleracea ◽

Chenopodium Album ◽

Microwave Drying ◽

Total Phenolic ◽

Drying Methods ◽

Drying Method ◽

Nutrient Quality ◽

Oven Drying ◽

Sun Drying ◽

Hot Air

The herbs, Chenopodium album Linn. and Spinacia oleracea Linn. belongs to Chenopodiaceae family, are the two nutritious and edible green leafy food crops, abundantly found especially in the northern-west region of India. These plants have gained renown popularity, because of their high nutritional content including protein, amino acids, carbohydrate, and even the presence of phenolic components, which ultimately may get affected with drying and storage techniques. Impact of different drying methods (microwave drying at 4 minutes, hot air oven drying at 5 hours and sun drying at 8-10 hours) on nutrient quality and antioxidant property of Chenopodium album Linn. and Spinacia oleracea Linn. leaves were evaluated by using UV spectrophotometritc assay, total phenolic content and DPPH free radical scavenger method. Drying treatments were significantly decreased the moisture, carbohydrate and protein content present in C.album and S. oleracea. Hot air oven drying method produced dried samples of C.album and S. oleracea had significantly similar antioxidant activity when compared with the samples obtained from sun drying method. The dried samples obtained from hot air oven drying technique showed significant presence of total phenolic content in C. album and S. oleracea (6.44±0.12 mg/g, 6.69±0.40 mg/g) whilst the traditional sun drying method produced 8.00±0.02 mg/g and 7.89±0.37 mg/g). It is concluded that microwave drying and hot air oven drying were the methods to preserve appreciable percentage of nutrient components compared to the fresh samples. On other hand, the traditional method produced substantial reduction of nutrient quality. From statistical analysis, hot air oven drying technique was considered as optimum method which showed satisfactory % retention of protein (65.86%) and carbohydrate (85.95%) at 5 hours (shorter time than sun drying time period) along with significant antioxidant activity (34.89 μg/mL and 35.60 μg/mL) similar as obtained from the traditional technique (32.00 μg/mL).

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Physicochemical Properties of Dried Apple Slices: Impact of Osmo-Dehydration, Sonication, and Drying Methods

Molecules ◽

10.3390/molecules25051078 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1078

Author(s):

Joanna Cichowska-Bogusz ◽

Adam Figiel ◽

Angel Antonio Carbonell-Barrachina ◽

Marta Pasławska ◽

Dorota Witrowa-Rajchert

Keyword(s):

Physicochemical Properties ◽

Osmotic Dehydration ◽

Convective Drying ◽

Drying Methods ◽

Drying Method ◽

Drying Time ◽

Hygroscopic Properties ◽

Fruit Samples ◽

Apple Slices ◽

Pre Treatment

Apple slices of the Elise variety were previously osmo-dehydrated in erythritol, xylitol, and sucrose for 2 h. In some parts of the experiment, 30 min of ultrasound pre-treatment (US) were applied. Afterwards, fruit samples were dried by convective (CD), microwave-vacuum (VM), and a combined method (CD/VM, mix two of them). The main aim of the research was to characterize an impact of osmotic dehydration, sonication pre-treatment, and drying method on the physicochemical properties of the dried apples. The use of sugar alcohols (xylitol, erythritol) in the production of dried apples did not badly affect the taste of the obtained dried products; it enabled a noticeable cooling/refreshing effect felt in the mouth when consuming a snack, and enabled the production of dried snacks with lower calorific value. Polyol residues in the product were at a level that was safe for consumers. The most popular convective drying was long lasting, whereas the VM drying method allowed for the shortest drying time, amounting to 76 min; moreover, additional application of ultrasounds reduced this time to 36 min. The combined drying method allowed the total duration of the process to be reduced 2–4.5 times. Ultrasound applied during osmotic dehydration did not significantly affect attributes of the descriptive sensory analysis for the obtained dried apples. The best hygroscopic properties, ensuring the storage stability of the dried product, showed dried apples previously osmo-dehydrated in erythritol and sucrose solutions.

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Effect of Freeze, Oven and Microwave Pretreated Oven Drying on Color, Browning Index, Phenolic Compounds and Antioxidant Activity of Hawthorn (Crataegus orientalis) Fruit

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha46211027 ◽

2018 ◽

Vol 46 (2) ◽

pp. 449-456 ◽

Cited By ~ 11

Author(s):

Hacer COKLAR ◽

Mehmet AKBULUT ◽

Semih KILINC ◽

Ali YILDIRIM ◽

Iliasu ALHASSAN

Keyword(s):

Antioxidant Activity ◽

Phenolic Compounds ◽

Total Phenolic Content ◽

Phenolic Content ◽

Total Phenolic ◽

Drying Methods ◽

Drying Method ◽

Microwave Pretreatment ◽

Oven Drying ◽

Freeze Dried

Flowers, leaves and fruits of hawthorn plant are traditionally used for treating diseases like hypertension and atherosclerosis. The medicinal effects of the plant are generally attributed to its phenolic compounds. However, the fruits are perishable materials because of their high content of water, and generally dried and stored to be used outside its season. The main aim of this research was to investigate the effect of different drying methods on phenolic compounds of the hawthorn fruit. Fruits were collected from the wild growing trees in Turkey. De-seeded fruits were dried in freeze-, oven- (60 oC) and microwave pretreated oven drying (microwave application for 5 min at 360 W before drying at 60 oC) methods and analyzed for antioxidant activity, phenolic compounds, total phenolic content and color parameters. Total phenolic content of fresh hawthorn fruits was found as 13.36 mg g-1 DW. Oven- and microwave pretreated oven drying methods had a reductive effect on total phenolic content and antioxidant activity of fruits when compared to freeze drying method. (-)-Epicatechin (994.10 mg kg-1 DW), rutin (765.30 mg kg-1 DW), and procyanidin B2 (553.80 mg kg-1 DW) were the main phenolics of the fruit. Lowest values of these three compounds were observed in oven-dried fruits. Microwave pretreatment oven drying method resulted in browner product. Although the highest phenolic concentration and antioxidant activity were occurred in freeze-dried sample, microwave pretreatment before oven drying could be applied to reduce the time and cost of drying in terms of phenolic compounds and antioxidant activity.

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The thin-layer drying characteristics of sewage sludge by the appropriate foaming pretreatment

Water Science & Technology ◽

10.2166/wst.2014.093 ◽

2014 ◽

Vol 69 (9) ◽

pp. 1859-1866 ◽

Cited By ~ 4

Author(s):

Hui-Ling Wang ◽

Zhao-Hui Yang ◽

Jing Huang ◽

Li-Ke Wang ◽

Cheng-Liu Gou ◽

...

Keyword(s):

Sample Thickness ◽

Coefficient Of Determination ◽

Drying Rate ◽

Drying Time ◽

Drying Characteristics ◽

Thin Layer Drying ◽

Dewatered Sludge ◽

Drying Curves ◽

Sludge Drying ◽

The Impact

As dewatered sludge is highly viscous and sticky, the combination of foaming pretreatment and drying process seems to be an alternative method to improve the drying performance of dewatered sludge. In this study, CaO addition followed by mechanical whipping was employed for foaming the dewatered sludge. It was found that the foams were stable and the diameters of bubbles mainly ranged from 0.1 to 0.3 mm. The drying experiments were carried out in a drying oven in the convective mode. The results indicated that foamed sludge at 0.70 g/cm3 had the best drying performance at each level of temperature, which could save 35–45% drying time to reach 20% moisture content compared with the non-foamed sludge. The drying rate of foamed sludge at 0.70 g/cm3 was improved with the increasing of drying temperature. The impact of sample thickness on drying rate was not obvious when the sample thickness increased from 2 to 8 mm. Different mathematical models were used for the simulation of foamed sludge drying curves. The Wang and Singh model represented the drying characteristics better than other models with coefficient of determination values over 0.99.

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Influence of Different Drying Methods on Drying Characteristics, Carotenoids, Chemical and Physical Properties of Gac Fruit Pulp (Momordica cochinchinensis L.)

International Journal of Food Engineering ◽

10.1515/ijfe-2015-0162 ◽

2016 ◽

Vol 12 (4) ◽

pp. 395-409 ◽

Cited By ~ 4

Author(s):

Wittawat Trirattanapikul ◽

Singhanat Phoungchandang

Keyword(s):

Antioxidant Activity ◽

Heat Pump ◽

Total Phenolics ◽

Microwave Drying ◽

Drying Methods ◽

Fruit Pulp ◽

Model Quality ◽

Drying Time ◽

Drying Characteristics ◽

Momordica Cochinchinensis

Abstract Gac fruit (Momordica cochinchinensis L.) pulp is high in carotenoids and fiber; however, it is discarded during process. Both maturity stages of matured gac fruit could be used in the drying experiments. Gac fruit pulp was dried by different drying methods including tray drying (40–60 °C), heat pump-assisted dehumidified drying (40–60 °C), microwave drying (450–900 W), mixed-mode solar drying and freeze drying. The Modified Henderson model presented the best fit of desorption isotherms. New model proposed was the best drying model. Quality evaluation by β-carotene, lycopene, lutein, total phenolics and antioxidant activity revealed that heat pump-assisted dehumidified drying at 60 °C provided the highest lutein, total phenolics and antioxidant activity and could reduce drying time by 25 % and increased lutein, total phenolics and antioxidant activity by 12.6 %, 32.0 % and 0.3 %, respectively and is more promising drying method for gac fruit pulp.

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