Microwave Oven Drying in the Gravimetric Phosphorus Method

1981 ◽  
Vol 64 (6) ◽  
pp. 1319-1321
Author(s):  
James R Melton ◽  
William L Hoover
Keyword(s):  
Microwave Oven ◽  
Microwave Drying ◽  
Distinct Advantage ◽  
Oven Drying ◽  
Yellow Precipitate ◽  
Conventional Drying

Abstract The gravimetric quinolinium molybdophosphate method for determining P2O5 in fertilizers, AOAC 2.026–2.028, has been modified to permit the precipitate to be dried in a microwave oven rather than a conventional drying oven. After the yellow quinolinium molybdophosphate precipitate is formed, cleaned up, and washed, it is placed in a microwave oven at 600 watts until dry. The quantity of precipitate remaining after microwave drying was equal to that obtained by drying according to AOAC 2.028 for several fertilizer samples. A distinct advantage of the described method is that the yellow precipitate will not char with reasonably excessive drying. Also, much less energy is expended with the microwave oven than with the drying oven.

scholarly journals Profil Suhu dan Kadar Air Kayu dalam Pengeringan Oven Pemanas dan Gelombang Mikro (Temperature and Moisture Content Profiles of Woods in Heating and Microwave Ovens Drying)

2021 ◽  
Vol 17 (2) ◽  
pp. 160-171
Author(s):  
Trisna Priadi ◽  
Gunes T W Giyarto
Keyword(s):  
Moisture Content ◽  
Microwave Oven ◽  
Microwave Drying ◽  
Temperature Profiles ◽  
Moisture Profile ◽  
Moisture Movement ◽  
Oven Drying ◽  
Pinus Oocarpa ◽  
Moisture Profiles ◽  
Made In

This research aimed to evaluate the profile of temperature and moisture content in Pinus oocarpa wood being dried with heating oven and microwave oven.  The size of samples were (25x70x120) mm3.  The temperature profiles in heating oven and microwave oven drying were taken every 10 minutes and 0.5 minutes, respectively. The moisture profiles in heating oven and microwave oven drying were made in every 24 hours and 10 minutes, respectively.  The heating oven was set at 60 °C, while microwave oven was set for 2 minutes intermittently with 5 minutes break.  In microwave drying, the temperature inside the boards increased faster and higher compared to that in the heating oven, which resulted in a faster moisture movement to the board’s surface.  The drying rate of pine increased 48-72 times in microwave compared to that in heating oven.  The moisture content in the centre of boards being dried in heating oven was much higher than that of in the outer parts.  On the other hand, the moisture profile in the woods being dried in microwave oven distributed more evenly.

scholarly journals The Effect of Microwave Oven Drying on the Compressive Strength of Type III and IV Dental Stones at Different Time Intervals

2018 ◽  
Vol 12 (1) ◽  
pp. 494-500
Author(s):  
Suha Fadhil Dulaimi ◽  
Sabiha Mehdi Kanaan
Keyword(s):  
Compressive Strength ◽  
Microwave Oven ◽  
Microwave Drying ◽  
Time Interval ◽  
Time Intervals ◽  
Mean Values ◽  
Oven Drying ◽  
Type Iii ◽  
Type Iv ◽  
Significant Difference

Background:Dental stone cast needs 24 to 48 hours to evaporate excess water and acquire enough strength for manipulation. The microwave oven is used to save time by drying and disinfecting stone casts.Objectives:The aim of the present study is to evaluate the effect of microwave oven drying on the compressive strength of Type III and Type IV dental stone in three time intervals-3 hours, 5 hours and 24 hours after pouring.Methods:The study involved 120 samples: 60 samples for each type of dental stone. Thirty samples were subjected to air drying at 3, 5 and 24 hours) and 30 samples were dried in the microwave oven at 2450 MHZ -900 W for 150 seconds (at 3, 5 and 24 hours). The samples were tested by unconfined compression machine, with a 2000 kg proving ring at cross-head speed of 1 mm/min.Results:For the Type III dental stone drying at 3 hours, microwave radiation causes a significant increase in compressive strength and shows the highest score (mean 125 kg/cm); however, at 5 hours no significant difference was observed. However, at the 24 hour time interval, microwave drying causes significant reduction in the mean (100 kg/cm)p<0.01 .For the Type IV dental stone testing at all-time intervals (3,5, 24 hours), a significant reduction (p<0.05) in mean values was shown(80,85,87 respectively).Conclusion:Microwave oven drying increased the compressive strength of Type III dental stone at the 3 hour time interval from pouring, while microwave drying at the 5 hour interval had no significant effect; and at 24 hour the compressive strength of the dental stone was reduced. For the Type IV dental stone microwave drying had a detrimental effect on compressive strength at all-time intervals.

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

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).

Evaluation of the Potential of Fruit Peel Biomass after Conventional and Microwave Drying for Use as Solid Fuel

2015 ◽  
Vol 798 ◽  
pp. 480-485 ◽  
Author(s):  
Andrea Teixeira Charbel ◽  
Bernardo Damázio Trinchero ◽  
Diego Dornas Morais ◽  
Henrique Mesquita ◽  
Viviane Santos Birchal
Keyword(s):  
Fossil Fuels ◽  
Average Energy ◽  
Correlation Coefficients ◽  
Passion Fruit ◽  
Microwave Drying ◽  
Fruit Peel ◽  
Conventional Drying ◽  
Pulp Processing ◽  
Average Energy Consumption ◽  
Time Required

Searching for new sources of energy in order to minimize the dependence on fossil fuels and also to preserve the environmentmeets thenecessityfor finding effective solutions to the problem of waste generated in different production levels.In juice pulp processing industrylarge volumes of waste are produced daily and can contribute, with its burning, for energy production. Once it is necessary the removal of moisture from the residue, this study evaluate the conventional drying and microwave drying of the biomass generated by peels of orange, mango and passion fruit with initial mean moisture content higher than 75%. The experiments were performed in oven at a temperature of 150°C and the average time for an almost complete withdrawal of peels studied was 130min. For drying by microwave with power of 900W, the average time required for the total reduction in moisture was 8.5min. The drying Page model was adjusted by non-linear regression to data obtained with correlation coefficients in all cases greater than 0.955. The higher heating value was rated equal to 16,25kJ/g, 19,62kJ/g, 16,35kJ/g for the peels of orange, mango and passion fruit, respectively. The average energy consumption for the drying process in the oven was 81,25kJ/gevaporated water and 12,07 kJ/gevaporatedwaterin the process by microwave, which indicates that drying using microwave is a very interesting option.

Microwave Oven Drying Determination of Total Solids in Processed Tomato Products: Collaborative Study

1985 ◽  
Vol 68 (6) ◽  
pp. 1081-1083
Author(s):  
Henry B Chin ◽  
John R Kimball ◽  
Joyce Hung ◽  
Bradford Allen
Keyword(s):  
Collaborative Study ◽  
Microwave Oven ◽  
Drying Method ◽  
Vacuum Oven ◽  
Oven Drying ◽  
Total Solids ◽  
Good Repeatability ◽  
Repeatability And Reproducibility ◽  
Tomato Products ◽  
Solids Content

Abstract Fourteen laboratories analyzed 7 samples of tomato products with total solids content ranging from 6.5 to 40.2%. Samples were analyzed directly with the exception of samples with solids contents greater than 15%, which were diluted with water (1 + 1 for up to 30% solids and 1 + 3 for greater than 30% solids). The 2-4 g samples were dried at 100% power for 4 min. The results of the collaborative study showed good repeatability and reproducibility: 5„ = 0.16 (CV = 0.46%) and S, = 0.36 (CV = 1.06%) for the higher solids samples and S„ = 0.37 (CV = 3.76%) and Sx = 0.14 (CV = 1.41%) for samples with total solids up to 15%. Results were compared with those obtained using vacuum oven drying. No difference was seen in the results by the 2 methods at the 95% level of confidence. The microwave oven drying method has been adopted official first action as an alternative to the vacuum oven drying method for total solids.

scholarly journals Study the Effect of Heating Process on Nutritional, Phytochemical and Antioxidant Activity of Mandarin Peel: Implication for Waste Management

2019 ◽  
Vol 11 (3) ◽  
pp. 365-372
Author(s):  
M. Shafiq ◽  
S. Firdous ◽  
Q. Irfan ◽  
S. J. Khan ◽  
A. Qadir
Keyword(s):  
Antioxidant Activity ◽  
Gallic Acid ◽  
Waste Product ◽  
Microwave Drying ◽  
Heating Process ◽  
Oven Drying ◽  
Sun Drying ◽  
Mandarin Peel ◽  
Ethanolic Extraction ◽  
Gallic Acid Equivalent

The aim of present study was to explore nutritional value of mandarin peel (waste product) and utilize it in feed or an alternative to synthetic supplements as it is a powerful source of vitamin C and polyphenolic contents. Mandarin peels were dried by placing them at three different heating systems (Sun, vacuum oven and microwave drying) and extraction was carried out using four different solvent systems (methanol, ethanol, acetone and aqueous). Present results showed that mandarin peels retain best nutritional quality on electric oven drying followed by sun drying and microwave drying systems. A significant amount of ascorbic acid was found as sun drying (18.34 mg) > electrical oven drying (17.49 mg) > microwave oven drying (15.22 mg) per 100 g of sample. Highest antioxidant activity of mandarin peels was observed in ethanolic extraction of electrical oven drying (89.38±0.7%). Maximum value of total phenolics content (TPC) was present in electrical oven dried (189±0.9 mg gallic acid equivalent /100 g) and sun dried sample (171.1±0.9 mg gallic acid equivalent/100 g) of ethanolic extraction. Total Flavonoid content (TFC) was present highly in ethanolic extraction of sun dried sample (376.55±0.7 mg quercetin equivalent/100 g).

Research on Measurement of Grass’s Moisture Content with Microwave Oven Method

2014 ◽  
Vol 707 ◽  
pp. 417-421
Author(s):  
Yan Feng ◽  
Qing Qing Shen ◽  
Li Li Chen ◽  
Shu Ling Luo ◽  
Guang Biao Jiang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Microwave Oven ◽  
Drying Method ◽  
Oven Method ◽  
Important Indicator ◽  
Oven Drying ◽  
Viable Method

In the process of working, storage, finished fodder acceptance and the preservation process of grass materials, the moisture content of forage is a very important indicator. The blast oven drying method has been generally adopted in the measurement of moisture content. The related experiment showed that the microwave oven method for grass moisture content measuring improved 200-400 times in the efficiency compared with blast oven drying method. The microwave oven method was accurate and easy operating. So, we can conclude that microwave oven method is a viable method for measuring the moisture content.

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