Effect of microwave drying on the content of sulforaphane in different parts of broccoli

ABSTRACT: Broccoli was used as raw material to determine sulfur content of radish in three different parts of broccoli flower, stem and leaf by high performance liquid chromatography (HPHC). Radish in the samples dehydrated by microwave drying equipment (wave power 900W, time 10min) and electric blast drying equipment (1000 drying temperature is 90 C, time is 2h) were compared and analyzed. The effects of microwave drying on the content of sulforaphane in broccoli were studied.

microwave drying equipment 

The results showed that the content of sulfur radish in different parts of broccoli dried by microwave was (152.50 t 0.27), (82.75 (1.28) and (23.720.18 mg kg, respectively. The content of sulfur radish in broccoli stems was about twice and seven times of that in broccoli leaves dried by electrothermal blast, and the content of sulfur radish in different parts of broccoli was the same. It is the highest in stems, 56.321.37mgkg, and (85.04 + 1.13) mgkg and (53.262.78) mgkg respectively in flowers and leaves.

Microwave drying and electric blast drying, broccoli leaf sulfur content surging greater, the stem and flower is not affected much, the leaves should be used electric blast drying stems and flowers can be used either wave thousand drying, or can also be used electric blast thousand drying keywords: wave thousand drying; broccoli; different parts; sulfur content of radish, contrast points The difference of sulforaphane content in broccoli samples obtained by microwave thousand drying (wave power 900W, time 10min) and electrothermal blast thousand drying (thousand drying temperature 90, time 2h) was analyzed. The effect of microwave thousand drying on sulforaphane content in broccoli was studied.

broccoli dried by microwave 

Experiment on microwave drying lotus root

1 materials and methods

1.1 materials and reagents

"Beauty Red Lotus Root: In May 2012 by the Jiangsu Province Yangzhou Baoying County Tianhe Food Co., Ltd. Lotus root is tender and tender, with pure white color and no obvious mechanical injury. After washing and peeling lotus root, the lotus root was sliced into 5-6 mm thick slices with stainless steel knife, and immediately soaked in 0.2% citric acid and 0.2% citric acid.

Microwave Drying Equipment 

1% sodium chloride color protector, half an hour later take out, blanching in boiling water for 3 minutes, flow water cooled to room temperature, put in 2% maltodextrin solution soaked for 1 hour, take out and drain, put in the refrigerator about - 18, freeze and reserve. The initial moisture content of lotus root slices before microwave drying is about

84%.

Citric acid, sodium chloride, maltodextrin are food grade; ascorbic acid, 2,6-dichloroindophenol, Folin reagent, acetone, sodium bicarbonate, oxalic acid, gallic acid, sodium carbonate are analytical pure.

1.2 instruments and equipment

DHG-9073B5-III Electric Heating Constant Temperature Blasting Drying Box (Shanghai Xinmiao Medical Device Manufacturing Co., Ltd.); MVD-1 Microwave Drying Equipment (Nanjing Xiaoma Mechanical and Electrical Equipment Factory); QDPH-5 Electric Heating Air Expansion Equipment (Tianjin Qinde New Material Technology Co., Ltd.);QTS texture analyzer (CNS Farnell, UK); FW100 high-speed universal crusher (Tianjin Tester Instrument Co., Ltd.); FA2104 cushion analysis balance (Beijing Saidoris Scientific Instrument Co., Ltd.); WSC-S color difference analyzer (Shanghai Precision Scientific Instrument Co., Ltd.); JSM-

5610LV scanning electron microscope (Japan Electronics);

JFC01600 gold plating instrument (Japan Jeol company).

microwave drying lotus root

Effects of different drying methods on the quality of lotus root chips

ABSTRACT: In order to determine the best drying method for leisure lotus root crisp slices, six different drying methods were adopted, including hot air drying,microwave drying equipment, hot air-vacuum microwave drying, hot air-air puffing drying, vacuum Microwave-Air puffing drying, hot air-vacuum Microwave-Air puffing drying. After drying, the quality indexes such as color, shrinkage, hardness, brittleness, VC retention, polyphenol retention and microstructure were analyzed.
microwave drying equipment

The results showed that hot air drying had little effect on the color of lotus root crisp slices, but the hardness was too low, brittleness was poor, VC and polyphenol loss was the most serious; vacuum microwave drying lotus root crisp slices VC and polyphenol retention rate was high, brittleness was good, but the hardness was too high, 

product shrinkage was serious, color difference and browning were high; The quality of lotus root crisp slices was better than that of single drying. The shrinkage and browning degree of lotus root slices dried by hot air-vacuum Microwave-Air puffing were significantly lower than that dried by vacuum microwave drying, while the retention rate of VC and polyphenols was significantly higher than that dried by hot air drying. The hardness, brittleness were moderate and the porosity was good. To sum up, hot air-vacuum Microwave-Air puffing drying is the most suitable method for processing lotus root leisure crisp slices.
 lotus root microwave drying

Study on variable temperature control method of Apple microwave drying

 Abstract: Microwave drying equipment can effectively shorten the drying time and improve the quality of apple dehydration. Six constant temperature microwave drying schemes and three variable temperature microwave drying schemes were used to study the drying characteristics and quality of apples under different schemes.

Microwave drying equipment 

The experimental results show that the drying rate of "constant temperature" drying scheme decreases slowly in the middle drying stage, which will result in lower quality of products. In the "drying rate control" scheme, the drying rate is controlled at a constant speed in the middle of drying, but there are some defects in the initial drying control; in the "linear temperature control" scheme, the drying rate is basically maintained at a constant speed in the middle of drying, and the drying time and energy consumption are reasonable, sensory quality and color quality are superior to the constant temperature drying; In the three-stage temperature control scheme, the complexity of the equipment used in the linear temperature control scheme is simplified. Although the product quality index is slightly decreased, the equipment is simplified, which is more conducive to industrial application. This study provides a technical basis for the application of microwave drying technology to Apple drying theory.

Key words: microwave drying, drying rate, temperature change, apple

Microwave drying technology is widely used in food industry because of its high efficiency and low energy consumption. In the process of Apple microwave drying, the electromagnetic wave emitted by magnetron directly acts on the ions and dipole molecule of the material, causing its vibration and mutual friction to produce heat, thus rapidly increasing the temperature of the object. If the magnetron stops working, the action of ions and dipole molecules in the object will stop immediately, and the temperature will drop faster than other ways of heating and drying from outside to inside. Therefore, by automatically adjusting the microwave power can quickly and effectively control the temperature of the object in the microwave drying process.

 Apple microwave drying

Study on the characteristics and quality of drying with hot air and microwaves of the germinated brown rice

The effect of the hot air drying equipment and the  microwave drying equipment on the drying characteristics, main nutrients, enzymatic power. The hardness and color of the sprouted brown rice were established. The mathematical model provides a basis for the prediction of microwave drying quality and the control of drying conditions.

 microwave drying equipment

The dry model and the Page equation based on the Fick diffusion law can be well adjusted to the hot air curves and microwave drying of the sprouted brown rice. With the increase of the temperature of the hot air or the increase of the specific power of the microwave, the speed of constant drying and the effective diffusion The energy of activation of the drying of hot air of the germinated brown rice was of 55.76 kJ / mol. The drying conditions have a significant effect on the main nutrient content, the enzymatic hydrolysis and the hardness of the sprouted brown rice. The sprouted brown rice undergoes a browning reaction during the drying process, and the color is probably yellow. The reddening of the germinated brown rice is obtained by drying with microwaves. It is greater than that of hot air drying.

Keywords: germinated brown rice; drying with hot air; drying with microwaves; mathematical model; γ-aminobutyric acid

It was germinated to obtain germinated brown rice under suitable environmental conditions such as temperature and humidity. During the germination process, the endogenous enzyme is activated, the outer layer of the crude fiber is softened enzymatically, the protein is degraded into polypeptides and amino acids. And the starch becomes sugar. Phytase degrades phytic acid in inositol and phosphoric acid, and also produces γ-aminobutyl. Physiologically active ingredients such as acid, ferulic acid and hexa-inositol phosphate improve the nutritional composition and taste of brown rice. .

Among them, GABA is a widely existing inhibitory neurotransmitter, which has the effects of preventing Alzheimer's disease, hypertension, anxiety and the search for lipid metabolism.

Fresh sprouted brown rice has a high water content, rich nutrition and mold, and drying is the key technology to improve the shelf life of sprouted brown rice. Currently, the research on the drying of the sprouted brown rice focuses mainly on the effect of the drying process on the speed of drying, the composition of nutrients, the processing properties and the color of the sprouted brown rice.

microwave drying of sprouted brown rice 

Vacuum microwave drying characteristics and kinetic model of Pleurotus abalone

Abstract: In order to understand the change of moisture content in Abalone Mushroom in vacuum microwave drying equipment, vacuum microwave drying experiments were carried out, and the effects of different vacuum (- 50, - 70, - 85 kPa), microwave power (250, 750, 1250 W) and loading amount (50, 100 and 150 g) on the vacuum microwave drying characteristics of abalone mushroom were obtained. The results showed that the vacuum microwave drying process of abalone mushroom conformed to Page equation (P This study provides a theoretical basis for the optimization and control of Pleurotus abalone in vacuum microwave drying process.

 microwave drying equipment

Keywords: Pleurotus abalone; vacuum microwave; drying characteristics; kinetic model.

Pleurotus is not only of high nutritional value and high pharmacological value, but also has broad prospects for deep processing. However, abalone mushroom has high moisture content, browning occurs on the surface of the mushroom after several days of storage at room temperature, autolysis of the fungus cover film occurs, and white flocculent mold grows and begins to rot, eventually losing edible value. This post-harvest ripening restricts the transportation and fresh sale of abalone mushroom. Therefore, we need to dry the Pleurotus mushroom to prolong its storage life. At present, the traditional drying methods of mushrooms are hot air drying and sun drying, but the drying time is long, resulting in dark color and nutritional loss of mushrooms. After rehydration, the mushroom body can not maintain the color and shape of the original mushroom body, affecting the edible sense organs. Therefore, the application of modern high-tech food drying technology to the dry production of Pleurotus eryngii is of great significance to improve the level of dry processing of Pleurotus eryngii and promote the production of Pleurotus eryngii.

Microwave drying technology of Pleurotus eryngii is a combination of vacuum drying and microwave drying technology, which has the advantages of high speed and efficiency. The change of material moisture content is significant for drying process and directly affects product quality. Limited to the modern drying technology, it is still a difficult problem to realize the on-line detection of moisture content in the drying process. Therefore, the study of moisture variation during the drying process will provide more theoretical basis for actual production.

Microwave drying technology of Pleurotus 

Effect of vacuum microwave drying on main carotenoids in pumpkin slices

Abstract: The main carotenoids in pumpkin slices were determined qualitatively and quantitatively by C30 column and high performance liquid chromatography-diode array detection-atmospheric pressure chemical ionization tandem mass spectrometry. The results showed that the total carotenoid content of pumpkin slices dried by vacuum microwave was significantly higher than that dried by hot air (P < 0.05). Microwave intensity had the greatest influence on carotenoids in pumpkin slices, followed by vacuum and slice thickness.

microwave drying equipment

With the increase of microwave intensity, the content of total carotenoids in pumpkin slices decreased significantly (P Meanwhile, the contents of main carotenoids alpha-, beta-carotene and lutein in pumpkin slices decreased with the increase of microwave intensity, and increased with the increase of vacuum and slice thickness, while the cis-isomers of beta-carotene decreased with the increase of vacuum, but the content of cis-isomers did not change significantly with the increase of slice thickness. It can be seen that increasing the vacuum and the thickness of the slices is beneficial to increase the carotenoid retention rate, while high microwave intensity makes the carotenoid content decrease.

Key words: Pumpkin slices; microwave drying equipment; carotenoids Pumpkin (Cucurbita moschata) is widely planted in China. It contains not only amino acids, vitamins, carbohydrates, pectin and trace elements, but also rich in carotenoids, especially alpha-carotene and beta-carotene. It has anti-oxidation, anti-cancer, prevention and treatment of cardiovascular diseases and immune system. Obstacles and other effects. Pumpkin is mainly used for fresh food, and its processing capacity is small. It often decomposes because it can not be sold or processed in time.

microwave drying of pumpkin