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Water activity and moisture content of selected …

Water activity and moisture content of selected …

The water content for most of the freeze-dried products varied from 0.01 to 0.1 g/g d.m., and water activity ranged from 0.08 to 0.330. ... View in full-text.

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Moisture and water activity values of fresh and dried …

Moisture and water activity values of fresh and dried …

Leaves were dried in a commercial digital microwave oven until there was virtually no change in weight. The initial moisture content and water activity (a w) …

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A Simplified Drying Procedure for Analysing Hg …

A Simplified Drying Procedure for Analysing Hg …

Jun 03, 2022 · The lower median Hg concentration in oven-dried samples has to be weighed against the upside efficiently drying large sets of peat samples. By freeze-drying a subset of the samples, we fitted a function to correct for Hg loss during oven-drying ( y=0.96x+0.08). By applying this correction, the freeze-drying bottleneck could oven-dry large-scale ...

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Effect of Spray Dryer Scale Size on the Properties of …

Effect of Spray Dryer Scale Size on the Properties of …

2.4. Moisture Content and Water Activity. All of the beetroot powders that were obtained were characterized by low values of both moisture content (2.84–3.10%) and water activity (0.18–0.23). This indicates that adequate microbiological stability was achieved for the beetroot powders obtained in all of the tested drying scales.

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Freeze‐dried, oven‐dried, and ... - Wiley Online Library

Freeze‐dried, oven‐dried, and ... - Wiley Online Library

Feb 27, 2020 · The present study was conducted to compare the antibacterial activity of oven-dried and freeze-dried Allium ... showed that the freeze-dried sample had a maximum loss in moisture of 58.8%, with a ... (70% W/V) and gum Arabic (AG) (30% W/V) as carrier (wall material). MDX and AG were previously dissolved in distilled water at 50 C stirred with ...

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Impact of Three Different Dehydration Methods on Nutritional Values …

Impact of Three Different Dehydration Methods on Nutritional Values …

Oct 14, 2020 · The moisture content and water activity of the REV-dried broccoli, orange, and carrot were tested on days 0, 7, 14, 28, and 42 after starting the experiment. The trend of changes is shown in Figure 6. As seen from the graphs, the moisture content and water activity of the REV-dried products stayed stable over the accelerated shelf life with no ...

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Effect of moisture content on the invertase activity of freeze-dried …

Effect of moisture content on the invertase activity of freeze-dried …

Freeze-dried yeast with water activity (Aw) between 0 and 0.33 (about the MMC value) maintained at 25 degrees C for 235 days and at 89 degrees C for 15 min retained at least 85% of its original invertase activity (IA), whereas samples with Aw > MMC lost at least 60% of its IA. X ray diffraction showed that the freeze-dried cake before and after ...

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The effect of drying methods on the physicochemical and …

The effect of drying methods on the physicochemical and …

All powders used in this showed an acceptable moisture content level, with a range of 2.11–2.31%. Spray dried and drum dried powders had the lowest value of moisture content and water activity. Moreover, spray dried powders showed the lowest value in hygroscopicity and bulk density and took the shortest time to wet the powder.

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Moisture and Water Activity - Routledge Handbooks

Moisture and Water Activity - Routledge Handbooks

dry matter content in food is inversely related to its moisture content, moisture content has great economic importance to the food processor and consumer. In meat, water or moisture is quantita-tively the most important component of the product, constituting up to 75% by weight.

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Comparison of suitable drying processes for mealworms

Comparison of suitable drying processes for mealworms

Dec 01, 2018 · The moisture content and water activity of dried mealworms of the preliminary drying experiments are shown in Table 1. These samples were not used for nutrient analysis, but merely served to adjust the drying time and temperature of the different drying techniques. ... The water activity for freeze-dried, vacuum dried and rack oven dried larvae ...

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Water sorption behavior and thermal analysis of freeze-dried ...

Water sorption behavior and thermal analysis of freeze-dried ...

Sep 01, 2012 · Moisture content and water activity in the açaí powder produced using Refractance Window drying were higher, followed by that dried with freeze-drying and hot-air drying methods. The dried powders showed a sigmoidal shape isotherm (type II), with hot-air dried açaí sorbing slightly more water than the other samples at all a w values.

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Water activity‐temperature state diagrams of freeze‐dried …

Water activity‐temperature state diagrams of freeze‐dried …

Jan 30, 2009 · Water activity measurements. a w of freeze-dried material and saturated salt solutions was measured at room temperature using an Aqua Lab CX-2 instrument (Aqua Lab, Pullmam, WA).. Experimental design of storage experiment. The bacteria cultures were placed in glass desiccators with saturated salt solutions in the bottom of the desiccators with a w 0.11 …

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Impact of oxygen and humidity on storage of freeze …

Impact of oxygen and humidity on storage of freeze …

The viability of freeze-dried Lactobacillus gasseri depends on the water activity. Increasing water activities decreased the bacteria survival as seen in Table 2. The highest water activity shows samples grated in aerobic condition and storage at 25 °C. The results show also that a w above 0.200 the viability loss is increased.

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Effect of Size and Drying Time on the Rehydration and …

Effect of Size and Drying Time on the Rehydration and …

categories with average weights: 7.59g (quarter-sized), 14.41g (half-sized), and 30.71g (whole), and freeze-dried for 15, 20, and 25h. The moisture content and percent rehydration of the dried samples were determined by standard methods and sensory properties assessed by an in-house panel of 30 using a 5-point hedonic scale. The moisture ...

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Water activity of freeze dried mushrooms and berries

Water activity of freeze dried mushrooms and berries

were frozen at -30°Cfor 5 days. The materials were then freeze dried in a Freeze Mobile (25L EL, Virtis, New York, NY) for 72 h with a tray temperature of25°C, under vacuum (13 Pa oftotal pressure) and a condenser temperature of-90°C.After freeze­ drying, the samples were put in a vacuum oven for 48 hours at

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THE PRODUCTION OF A DRIED AVOCADO (Persea …

THE PRODUCTION OF A DRIED AVOCADO (Persea …

after 72h, and a final average water activity of 0.356. Drying occurred in the falling rate period and the drying rate constant (k 1) averaged 0.2496 1/h. The Verma model was found to best fit the Moisture Ratio (MR) data. Compared with oven-dried samples, the freeze-dried samples dried to lower equilibrium moisture values, did not show any ...

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Freeze‐dried, oven‐dried, and microencapsulation of …

Freeze‐dried, oven‐dried, and microencapsulation of …

ing moisture content of garlic samples (Aware & Thorat, 2011). Tests proved that more than 95% of the antioxidant activities remained in the freeze-dried preparations (Leelarungrayub, Rattanapanone, Chanarat, & Gebicki, 2006) and the preservation of the allicine is more effective in freeze-dried samples at 20°C (Ratti et al., 2007).

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Effect of drying procedures on nutritional composition

Effect of drying procedures on nutritional composition

Nov 19, 2018 · Fresh wheatgrass was dried using shade, oven and freeze drying methods. The ascorbic acid and β-carotene and content of oven dried wheatgrass was significantly lower (133.13 µg and 1.98 mg) in comparison to shade dried (193.62 µg and 2.30 mg) and freeze dried (230.35 µg and 3.18 mg) wheatgrass. A significantly lower iron and zinc was observed …

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The effect of drying methods on the physicochemical and …

The effect of drying methods on the physicochemical and …

All powders used in this showed an acceptable moisture content level, with a range of 2.11–2.31%. Spray dried and drum dried powders had the lowest value of moisture content and water activity. Moreover, spray dried powders showed the lowest value in hygroscopicity and bulk density and took the shortest time to wet the powder.

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Effect of Spray-Drying and Freeze-Drying on the Properties of ... - Hindawi

Effect of Spray-Drying and Freeze-Drying on the Properties of ... - Hindawi

The properties of different dried samples were compared using solubility, hygroscopicity, moisture content, water activity, flowability, and glass transition temperature ( T g ). ... The supernatant (25 mL) was added to porcelain dishes and dried to constant weight in an oven at 105°C. Solubility was expressed as the ratio of the weight of the ...

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Freeze Drying Process - Discover Food Tech

Freeze Drying Process - Discover Food Tech

Feb 26, 2018 · Freeze Drying Definition. Lyophilisation or freeze drying is a process in which water is frozen followed by its removal from the sample initially by sublimation (primary drying) and then by sublimation (desorption).Since heat is not applied in this case.So,both nutritional qualities and sensory characteristics were better retained.Freeze drying ...

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Effects of Freeze Vacuum Drying Combined with Hot Air Drying ... - Hindawi

Effects of Freeze Vacuum Drying Combined with Hot Air Drying ... - Hindawi

The moisture content and water activity of kiwifruits manufactured with different drying methods are shown in Table 2. Significant differences were observed among drying time, hardness, moisture content, and water activity of the selected drying methods (). The initial moisture content of fresh kiwifruit was at 87.55% ± 1.64%, dry basis ...

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Water activity of freeze dried mushrooms and berries

Water activity of freeze dried mushrooms and berries

were frozen at -30°Cfor 5 days. The materials were then freeze dried in a Freeze Mobile (25L EL, Virtis, New York, NY) for 72 h with a tray temperature of25°C, under vacuum (13 Pa oftotal pressure) and a condenser temperature of-90°C.After freeze­ drying, the samples were put in a vacuum oven for 48 hours at

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Drying cannabis - The cannabis processor’s complete guide to moisture …

Drying cannabis - The cannabis processor’s complete guide to moisture …

Apr 15, 2020 · A moisture model is simply a graph of how water activity changes as a product is dried and as it absorbs water. This is the generic isotherm for drying cannabis. Different strains of cannabis can have widely divergent flower sizes, densities within the flower, and chemical makeup of volatiles in the dried crop.

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Comparative study of physicochemical properties of …

Comparative study of physicochemical properties of …

2.1.5 Water activity The non-bound water that is available for the growth of microbes refers to the water activity and the water activity of the TD/FD raw jackfruit flour was determined using Aqua Lab 4TE Dew point water activity meter. The flour was filled in the sample holder and the meter was allowed to read which

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Effect of Size and Drying Time on the Rehydration and …

Effect of Size and Drying Time on the Rehydration and …

categories with average weights: 7.59g (quarter-sized), 14.41g (half-sized), and 30.71g (whole), and freeze-dried for 15, 20, and 25h. The moisture content and percent rehydration of the dried samples were determined by standard methods and sensory properties assessed by an in-house panel of 30 using a 5-point hedonic scale. The moisture ...

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ANTIOXIDANT PROPERTIES OF PROCESSED CHEESE …

ANTIOXIDANT PROPERTIES OF PROCESSED CHEESE …

(GS) were dried at the following conditions: oven-drying (OD) was performed in laboratory air-forced oven (HS62A, Chirana, Brno, Czech Republic) at 46 °C for 24 h. Freeze-dried (FD) samples were prepared at -40 °C (12 Pa) for 48 h (CoolSafe 100-4, Trigon Plus, Čestlice, Czech Republic). Dried grape skins were milled at 5000 rpm for

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Freeze-dried soil is more suitable for studyi | EurekAlert!

Freeze-dried soil is more suitable for studyi | EurekAlert!

Mar 05, 2020 · "We evaluated soil water content, pH, (in)organic N content, and N r gas fluxes of air-dried, freeze-dried, oven-dried, and fresh soils from different land-use types," says Dr. Wu.

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What is freeze-dried? - K9 Natural

What is freeze-dried? - K9 Natural

Oct 29, 2020 · When a product is freeze dried, its water activity is reduced below the level at which pathogens can grow. This ‘water activity level’ differs from moisture and refers to how much water is actively available in the product at any given time to react and affect the solid aspects of the diet (ie; meat and whole food ingredients).

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EVALUATION AND CHARACTERIZATION OF FREEZE …

EVALUATION AND CHARACTERIZATION OF FREEZE …

60-mesh sieve to obtain a homogeneous powder. The freeze-dried powder was stored in a desiccator until further analysis. To compare the characteristics of freeze-dried papaya powder with hot- air oven dried papaya powder, fresh mature papaya juice mixed with maltodextrin was dried at 60°C by using hot -air oven dryer.

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The influence of the closure format on the storage

The influence of the closure format on the storage

chemical reactions which can lead to a loss of activity. Freeze dry-ing is able to extend the shelf life of these materials and increase the stability by producing a solid state final product form with very low moisture content. However, high moisture content in freeze-dried cakes can lead to loss in biological potency and an increase

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COMPARATIVE STUDY OF SPRAY-DRYING AND FREEZE

COMPARATIVE STUDY OF SPRAY-DRYING AND FREEZE

lower antioxidant activity than SD dried coffee. The lower antioxidant activity of freeze dried coffee can be explained considering the duration of the drying method which is larger for freeze-drying (hours) comparative with the spray-drying (seconds). Similar conclusion was obtained when the antioxidant activity was analyzed as total phenolic ...

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MOISTURE CONTENT BY THE OVEN-DRY METHOD …

MOISTURE CONTENT BY THE OVEN-DRY METHOD …

use the following formula to calculate moisture content. Initial weight - Oven - dry weight MC - x 100% (2) Oven - dry weight Formulae one and two are the same, one is conceptual, two is what you put into the calculator or spreadsheet. Equipment Needed for the Oven-dry Test To do the oven-dry test one needs a saw, oven, and scale. The total cost of

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(PDF) Water activity-temperature state diagrams of freeze-dried …

(PDF) Water activity-temperature state diagrams of freeze-dried …

After freeze drying, the Water activity measurements water activity of the dried samples was below the detection limit (0.037), and they were stored at 40 C in sealed aw of freeze-dried material and saturated salt solutions metallized bags until further use.

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Freeze Drying Process - Discover Food Tech

Freeze Drying Process - Discover Food Tech

Feb 26, 2018 · Freeze Drying Definition. Lyophilisation or freeze drying is a process in which water is frozen followed by its removal from the sample initially by sublimation (primary drying) and then by sublimation (desorption).Since heat is not applied in this case.So,both nutritional qualities and sensory characteristics were better retained.Freeze drying ...

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White Paper: Moisture Determination of Freeze Dried Product

White Paper: Moisture Determination of Freeze Dried Product

Quantifying the amount of water vapor in the headspace of freeze dried vials using an optical method enables rapid non-destructive moisture determination which could replace the slow destructive traditional methods for the moisture analysis of freeze-dried products. Download this White Paper to get an introduction to laser-based headspace ...

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Water sorption behavior and thermal analysis of freeze-dried ...

Water sorption behavior and thermal analysis of freeze-dried ...

Moisture content and water activity of the dried samples were evaluated after drying and during three-month storage at room temperature. ... 1890 Institution Capacity Building Grants ( #2006-05897-00-01, A4873 ). The authors thank Liotécnica for providing the freeze-dried açaí, MCD Technologies for performing the RW drying of açaí juice ...

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Freeze Dried Useslower Temperature Than Oven Dried

Freeze Dried Useslower Temperature Than Oven Dried

A Guide To Freeze Drying for the Laboratory - Chemicals-80 C. The product should be freeze dried at a temperature slightly lower than its eutectic or collapse temperature (Point B) since the colder the product, the longer the time required to complete primary drying, and the colder the collector temperature required to adequately freeze dry the product.

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Effect of Moisture content on the drying rate using …

Effect of Moisture content on the drying rate using …

During drying moisture content and water activity are reduced and hence microorganisms cannot grow and multiply to spoil fish. This will help in preserving fish for a long ... The residue was then dried in an oven at 1050C then weighed into a clean crucible and ash for 3 hours at 5000C. Crude fibre was calculated using the equation:

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