Effects of drying methods on the extraction amount and antioxidant activity of phenols from Macadamia green peel

In this study, fresh Macadamia green peel was used as control group to study the effects of hot air drying at 60 ~C, microwave drying equipment and vacuum freeze drying on total phenols and flavonoids extraction and antioxidant activity of Macadamia green peel.

microwave drying equipment 

The results showed that compared with the control group, different drying treatments had effects on the total phenol, total flavonoids and antioxidant activity of Macadamia green peel. Vacuum freeze-drying treatment had the least effect on them. The total phenol and total flavonoids were 935.61 and 995.75 mg/hg, respectively. The half scavenging rates of DPPH radical and ABTS radical IC50 were 6.83 and 63.84 mg/L, respectively, and the total antioxidant capacity was about 6.83 and 63.84 mg/L. It was 1.74 times as much as Trolox, and there were significant differences in total phenols, total flavonoids and antioxidant activity of Macadamia green peel after different drying treatments (p < 0.05).

microwave drying of nuts 

Effects of Different Drying Technologies on Bioactive Components in Wheat Seedlings

ABSTRACT: The wheat seedlings were dried in different ways, and the effects of different drying conditions on their bioactive components were explored, and an optimum drying process was obtained. The contents of total chlorophyll, polysaccharide, flavonoids and polyphenols were determined by colorimetry.

microwave drying equipment

The results showed that the highest total chlorophyll content was 82.33 mg/100 g when microwave drying equipment was 560 W; the highest polysaccharide and polyphenol content was 19.87 mg/g and 5.80 mg/100 g when oven drying temperature was 90 degrees C; the highest content of flavonoids was 5.29 mg/100 g when microwave power was 420 W; conclusion: the best drying condition was oven drying temperature 90 degrees C, microwave drying. The power is 420 W.

microwave drying of wheat see

Effects of drying methods on quality and antioxidant capacity of okra flower tea in vitro

ABSTRACT: In order to study the effects of different drying methods on the quality and in vitro antioxidant capacity of okra flower tea, the okra flower was treated by 50 ~C hot air drying, 70 ~C hot air drying, microwave drying equipment and vacuum freeze drying. The appearance quality, color, polysaccharide content, flavonoid content, antioxidant capacity and sensory quality of okra flower tea were analyzed.

microwave drying equipment

The results showed that there was no significant difference in appearance quality and antioxidant capacity between Okra tea and tea dried by 50 ~C hot air drying and 70 ~C hot air drying (P > 0.05), but there was slight difference in polysaccharide and flavonoid content. The okra tea dried by microwave drying had severe shrinkage in appearance, burnt paste in interior and exterior, but strong aroma and high antioxidant capacity in vacuum freeze-drying place. Li’s okra flower tea has symmetrical appearance and bright color. The content of polysaccharides and flavonoids in flower tea and flower tea water is the highest, and the antioxidant ability is the highest. The color of flower tea water is golden and transparent, and the flavor is pure, but the fragrance is mild. The results provide technical guidance for comprehensive utilization and processing quality control of okra tea.

okra tea microwave drying 

Effects of Different Treatments on the Extraction Rate and Composition of Essential Oil of Bayberry Leaves

Abstract: The effects of fresh, dry-drying, microwave drying equipment, blast drying and vacuum freeze-drying on the yield and composition of the essential oils of Chinese bayberry leaves were compared and analyzed. The essential oil of Chinese bayberry leaves was extracted by steam distillation, and the components of the obtained essential oils were separated and identified by GC-MS.

microwave drying equipment

The results showed that different treatment methods had a great influence on the yield and composition of essential oil of bayberry leaf. The yield of essential oil was fresh leaf < microwave drying < natural dry < blast drying < vacuum freeze drying. The essential oils obtained by the five treatment methods identified 33, 43, 42, 39, and 41 compounds, respectively, accounting for 96% of the total. 45%, 96. 1%, 97. 38%, 97. 28%, 68. 03%, both cis-4-cyclopentene-1,3-diol, α-rhedene, ( + ) - 4 -heptenol, transcaryophyllene, epoxidized hopene II, Dianthus Mainly based.

bayberry leaf microwave drying; essential oil 

Effect of Cutting Treatment on Microwave Drying Characteristics of Huping Jujube

Absrtact: Taking Hupingzao jujube as test material, half and ¼ of the jujube seeds were separately cut, and the whole jujube seeds were treated by microwave drying equipment under different microwave power. The effects of different cutting treatments on the microwave drying characteristics of Hupingzao jujube were discussed.

microwave drying equipment

The results showed that the microwave drying time was shortened, the rehydration ratio and sensory quality of the dried jujube were improved, but the Vc loss was increased to some extent. Considering comprehensively, the best drying effect was obtained when half-fruit was used as the shape of dried fruit under 160W microwave for 60 minutes.

Key words: microwave drying of jujube; segmentation; characteristics; quality

Jujube is one of the unique fruits in our country, which is very popular with consumers. However, because of the high water content of fresh jujube, it is easy to rot and deteriorate after harvest, which brings great economic losses to jujube farmers. Therefore, it is important to study the suitable storage, preservation and processing methods for jujube for promoting the healthy development of jujube industry.

microwave drying of jujube 

Effect of Painless Drying Method on the Quality of Poria cocos

ABSTRACT: Objective To compare the effects of hot air drying, infrared drying, microwave drying and low temperature adsorption drying on the quality of Polygonum umbellatum. The drying rates of the four drying methods were compared. The rehydration and appearance of the dried products were tested and evaluated, and the total yellow pour content in the dried products was determined by ultraviolet spectrophotometry.

Microwave drying equipment

Result Microwave drying equipment had the fastest speed, and the product had better rehydration, while low temperature adsorption drying had advantages in flavonoid content retention and appearance color.

Key words: microwave drying of tuckahoe cocos; flavonoids; hot air drying; infrared drying; microwave drying; low temperature adsorption drying; ultraviolet spectrophotometry

Poria cocos is the root of Ilex glabrata, a liliaceous plant. Its taste, light, flat nature, return to the liver and intercalated meridians are commonly used Chinese herbs for clearing away heat and detoxification. It has the functions of regulating diarrhea, strengthening spleen and stomach, strengthening muscles and bones, removing dampness, and promoting joints. It is clinically used to treat limb constriction, muscle and bone pain caused by dampness and heat, hypoderma, scabies, syphilis and mercury poisoning. Recent studies have shown that Tufa cocos has anti-cancer, anti-atherosclerosis and treatment of coronary heart disease and other pharmacological effects.

microwave drying of tuckahoe cocos 

Application of Microwave Technology in the Processing of Needle-shaped Green Tea

Absrtact: Green-killing and drying are the key processes in the processing of needle-shaped green tea. The application of microwave technology to green-killing and drying of tea is conducive to improving its quality. In order to improve the quality of needle-shaped green tea, the effects of microwave, drum, steam-heat combination and steam-heat-microwave combination, microwave drying and traditional drying on the quality of needle-shaped green tea were studied.

microwave drying equipment

The results showed that the combination of steam-heat and microwave was the best way to kill green tea, and microwave was more beneficial to improve the appearance, color and leaf bottom of needle-shaped green tea than the other three methods, which would damage its aroma and taste, but the combination of microwave and steam-heat could improve the sensory quality of needle-shaped green tea; caffeine, tea polyphenols, amino acids, vitamin C and leaves. The retention of main components such as chlorophyll was the highest in microwave-killed needle-shaped green tea.

tea microwave drying 

Process optimization of microwave drying of purple sweet potato powder

The composition of colour-protecting solution, colour-protecting time and the effects of microwave drying and hot air drying on purple sweet potato powder were discussed.

Microwave drying equipment

The optimum technological parameters are as follows: the color-protecting liquid is composed of 0.8% salt, 0.6% citric acid and 0.4% ascorbic acid. The color-protecting time is 6 minutes, and the microwave drying time is about 10 minutes. Microwave drying equipment can effectively retain the flavor and nutritional components of purple sweet potato, and improve the quality of purple sweet potato powder.

Key words: Purple sweet potato powder microwave drying; color protection; color difference value;

Purple sweet potato originated in southern Kyushu, Japan. It was introduced into China in 1990s and successfully planted. Purple sweet potato is rich in dietary fiber, minerals and vitamins, and has the health function of cancer prevention and anti-cancer. Purple sweet potato is rich in purple anthocyanin, which has special use and nutritional value.

Purple sweet potato powder microwave drying 

Application of Microwave Drying in Taro Chips Processing

Absrtact: Taro was used as raw material, microwave drying equipment and vacuum oil bath were used to study the effects of different processing parameters on water content, oil content and sensory quality of products, and a new processing technology of taro chips was established.

microwave drying equipment

The results showed that taro chips with low oil content, smooth appearance and good crispness could be obtained by vacuum oil bath (initial oil temperature 110 C, termination oil temperature 98 C and vacuum degree 0.098 MPa) for 5 minutes, controlling moisture content of products between 30% and 35%, and then microwave drying (microwave power 1 200 W) for 60 minutes. The oil content of the products processed by this new process is low, and the energy saving is 23% compared with the traditional process. It is a feasible new processing technology for fruit and vegetable crisps.

microwave drying taro

Effect of drying process on the quality of low temperature sausage

Abstract: The low temperature sausage was prepared by using pork and fish paste as the main raw materials. The drying conditions were optimized. The effects of hot air drying time, microwave drying equipment and microwave time on the quality of low temperature sausage were discussed.

microwave drying equipment

The results showed that with the prolongation of hot air drying time, the shape, color, taste and taste of the sausages increased, and the difference between internal and external moisture decreased. After microwave treatment, it helps to balance the internal and external moisture and improve the uniformity of color. Sensory quality, however, too long a time will cause poor taste of the meat, excessive hardness, and decreased chromaticity. The optimum drying process of the low temperature sausage is dried by a hot air drying oven at 55 ° C for 14 hours, and then dried by a microwave of 250 W for 90 s.

meat sausage microwave drying 

Effects of Different Drying Methods on Quality Characteristics of Purple Potato

Absrtact: In order to improve the quality of dried purple potato products, the effects of hot air drying, microwave drying equipment, vacuum drying and solar assisted heat pump combined drying on the physical and chemical properties and structure of dried purple potato were studied.

microwave drying equipment

The results show that there are significant differences in energy consumption, color, functional ingredients, hardness and structure of products obtained by different drying methods. Microwave drying has the highest drying efficiency, but its color and structure are poor. Vacuum drying products have the highest retention rate of functional ingredients, but the lowest drying efficiency and the largest energy consumption. The products obtained by solar heat pump drying have the highest drying efficiency and energy consumption. The comprehensive performance of consumption, color and structure is the best, and the product quality is good.

purple potato microwave drying 

Development of Quick-ripening Mung Bean by Microwave Drying Technology

Absrtact: To determine the processing technology and parameters of quick-ripening mung bean by microwave drying equipment. By studying the conditions of soaking, steaming and drying of mung beans, the optimum technological parameters of ripening and drying of quick-ripening mung beans were determined.

microwave drying equipment

The optimum technological parameters of quick-ripening mung bean are as follows: soaking temperature 50 C, soaking time 3 h, steaming time 20 min, microwave drying power P50 W, microwave drying time 13 min. The quick-ripening mung bean processed under this process has good rehydration and sensory state.

Key words: quick ripening; mung bean microwave drying; rehydration

Mung beans are the main cultivated beans of Asiatic cowpea subgenus. China has a long history of cultivation as a country of origin. Mung bean is rich in protein, carbohydrate, calcium, phosphorus, iron, thiamine, riboflavin, carotene and other nutrients.

mung bean microwave drying 

Effects of different drying methods on physicochemical properties of egg yolk powder

Abstract: spray drying, vacuum freeze drying, hot air drying, infrared drying andmicrowave drying equipment were used to study the effects of different drying methods on the physicochemical properties of egg yolk powder. The moisture content, thermal stability, color, emulsifying property and powder structure of yolk powder prepared by different drying methods were determined.

microwave drying equipment

The results showed that the moisture content of yolk powder was the lowest (2.5%), and the moisture content of yolk powder was the highest (3.9%). The difference between the two groups was significant (P<0.05). The moisture content of yolk powder from these 5 drying methods was less than 4%, which accords with the current standard of egg products. The color of yolk powder obtained from hot air drying is the worst (brightness is only 83.45). The egg yolk powder obtained by vacuum freeze-drying is the best emulsifying power, while the dried egg yolk powder has the worst emulsifying ability. The powder of egg yolk powder prepared by spray drying is spherical and uniform, and the egg yolk powder produced by the 4 drying methods is massive.

microwave drying of yolk powder 

Effect of drying methods on aging characteristics of instant rice flour

Abstract: Rapid Visco Analyser (RVA), X-ray diffraction and FTIR were used to study the effects of different drying methods (freeze-drying, hot-air drying, microwave drying equipment) on the aging characteristics of instant rice flour.

microwave drying equipment

The results showed that the absorbance ratio, crystallinity, gelatinization temperature and retrogradation value of instant rice flour obtained by hot air drying were the largest at infrared 1 047/1 022 cm-1, indicating that the aging degree of instant rice flour obtained by freeze-drying was the smallest, followed by microwave drying.

The rehydration rate and rehydration time of instant rice flour obtained by different drying methods were studied. The rehydration rate of freeze-drying was the best and that of hot-air drying was the worst. The rehydration performance of instant rice flour may be related to its aging degree in drying process.

microwave drying instant rice flour 

Study on the effect of drying methods on fresh-keeping and quality of semi-dry noodles

Absrtact: Ultraviolet-microwave drying and electrothermal drying were used to dry fresh and wet noodles. The effects of microwave drying equipment on the microbial content and quality of semi-dry noodles were compared and analyzed.

microwave drying equipment 

The results showed that the electrothermal drying efficiency was low, and the sterilization effect was not obvious at the later stage of drying; the ultraviolet-microwave drying efficiency was high, and the bacterial content of noodles continued to decline at the later stage of drying. Both drying methods could significantly reduce the initial bacterial content of semi-dry noodles.

For electrothermal drying, the total number of bacteria in semi-dry noodles decreased significantly at 125 C, which had little effect on texture and cooking quality. For ultraviolet-microwave drying, the initial bacterial content of semi-dry noodles was significantly lower than that of electrothermal drying at different power levels. When the microwave power was 2 000 W, the quality of semi-dry noodles was better, which was the more suitable microwave drying power.

semi-dry surface microwave drying 

Effects of different drying methods on quality of Seedless white raisins

Abstract: [Objective] To study the effects of different drying methods on the quality of Seedless white raisins.

microwave drying equipment

[Method] Fresh seedless white grapes were used as experimental materials. Six drying methods were adopted, including dry, air-drying, constant temperature air-drying, normal temperature air-drying, vacuum freeze-drying and microwave drying equipment. The drying speed, sensory index and sugar content, acid content and VC content of grapes were used as evaluation indexes to compare the effects of different drying methods.

[Result] The effects of different drying methods on the drying speed of Seedless white grapes were studied. The microwave drying time was the shortest, 3 days and the drying time was the longest, 13 days; the sugar content of vacuum freeze-dried raisins was the highest (78%) and that of sun-dried raisins was the lowest (72%); the total acid content of vacuum freeze-dried raisins was the lowest (1.62%) and that of sun-dried raisins was the highest (2.05%). The VC content of raisins was the highest (11.54 mg/100g) and that of raisins dried by sun was the lowest (7.9 mg/100g). The sensory indexes of vacuum freeze-drying and microwave drying were better.

microwave drying of white raisins