Effects Of Various Drying Methods Research Articles

Effects of Various Drying Methods on the Proximate Composition and Antioxidant Activities of Stellaria media Leaves

Background: Stellaria media belongs to the family of Caryophyllaceae. The plant is widely distributed in cold and temperate region all over the world. However, different parts of the S. media plant have been used to treat various disorders such as diarrhoea, jaundice, asthma, gastrointestinal disorders, measles, renal, reproductive, digestive, and respiratory tracts inflammations. Aims: This investigation is aimed to determine the proximate composition and antioxidant activity of S. media leaves by using three different drying methods- Sun drying (SD), Shadow drying (SHD), and Oven drying (OD). Methodology: All the experiments were performed according to standard procedures of the Association of Analytical Communities (AOAC). In this study, the effect of drying method on the proximate composition, mineral content, and antioxidant activity such as total flavonoid content, DPPH, and FRAP were investigated. Results: The result was compared with the fresh leaves (FL) of the S. media. FL of S. media was recorded to have maximum amount of moisture content. Also, the ash content which was determinant of minerals content was higher in OD sample compared with the FL and other drying methods. Protein and crude fiber were higher in dried samples as compared with the FL. Furthermore, levels of calcium (Ca) and iron (Fe) were higher in SD sample as compared with FL, SHD, and OD samples. Meanwhile, the total flavonoid content (TFC) 652.0±0.56 mg quercetin/g was highest present in OD sample in methanol extract. The inhibition percentage in DPPH ranged from 4.8±0.17 in FL in water extract to 95.8±0.21 in OD samples in methanol extract. The value of FRAP ranged from 9.0±0.42 µmol FeII/g in FL in water extract to 9277.0±0.33 µmol FeII/g in OD samples in methanol extract. Also, the result showed in both DPPH and FRAP highest value in OD sample in methanol extract as same as TFC. Conclusion: Nutrients and antioxidants help to maintain the nutritional status as well as to prevent various diseases. Therefore, they should be included as a dietary supplement. Furthermore, this represents a driver for future research in this field to consider different drying methods and determine the change in antioxidant activity using the high-performance liquid chromatography (HPLC) method.

The Effect of Various Drying Methods on the Quality of Rose (Rosa damascena) Tea

The Effect of Various Drying Methods on the Quality of Rose (Rosa damascena) Tea

Effect of Various Drying Methods on Physicochemical and Bioactive Properties of Quince Fruit (Cydonia oblonga Mill.)

The quince (Cydonia oblonga Mill.), due to its valuable bioactive properties and high health-promoting potential, is becoming more and more popular for the prevention of many free radical diseases. Due to the high hardness of the flesh and its bitterness and astringency, quinces are rarely eaten in the form of fresh fruit, and much more often in the form of various preserves, or in the form of dried additives, e.g., to the tea. Heat treatment (including drying) affects not only the content of bioactive compounds, but also the antioxidant activity and organoleptic characteristics. Therefore, this study examined the physicochemical properties of quinces (including the content of dry matter, soluble solids (°Brix), water activity (aw), pH, total acidity and color changes (in the L*a*b* space)), fresh and dried by various methods, i.e., freeze-drying and convection at 50 °C and 70 °C. In addition, the effect of various drying conditions on the content of selected bioactive compounds, i.e., tannins, carotenoids, flavonoids, phenolic acids and total polyphenols, was assessed, as well as the antioxidant properties of fresh quinces and quinces dried under different conditions. Based on the research, it can be concluded that the applied processes of the dehydration of quinces significantly changed both the physicochemical properties and the content of biologically active ingredients and antioxidant properties, while both fresh and dried fruit provide nutritionally valuable bioactive ingredients and show high antioxidant potential. Considering the great taste and bioactive qualities of the common quince, introducing it to the daily diet, whether in a traditional form (dried fruit, fruit preserves) or in the form of dietary supplements, can be an important element in the prevention of many civilization diseases.

Effects of Various Drying Methods on Physicochemical Characteristics, Flavonoids and Polyphenol Content, and Antioxidant Activities of Different Extracts from Morinda citrifolia Fruit

Introduction: M. citrifolia is known as a medical plant in Vietnam, named Noni, which contains numerous bioactive ingredients and applying good in functional food and pharmaceuticals. The notices on the change of physicochemical characteristics (color, pH, total solids, and titration acid), the content of flavonoids and polyphenol, and antioxidant activities (total, reducing power, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical scavenging) of different extracts from Morinda citrifolia fruit at various drying methods (solar energy, microwave, and heat pump), microwave power, and temperature have not been found. Therefore, the paper focused on these things.
 Methods: Morinda citrifolia fruit were harvested in July 2020, dried by using different methods (solar energy, microwave, and heat pump), and soaked in 96% solvent (ethanol and aqueous) for evaluating physicochemical characteristics, flavonoids and polyphenol content, and antioxidant activities. Drying M. citrifolia was at the temperature (50, 60, and 70°C) and the microwave power (100, 200, 400, 600, and 800 W), corresponding to the heat pump method and the microwave method, respectively and evaluating the drying speed curve basing on the moisture of M. citrifolia according to the drying time.
 Results: Physicochemical characteristics, flavonoids content, polyphenol content, and antioxidant activities (total, reducing power, and DPPH free radical scavenging) were affected by various drying methods, different extracting solvents (p<0.05) and changed the drying time, microwave power, and temperature according to the non-linear model of level 2. The stabilization of physicochemical characteristics, flavonoids content, polyphenol content, and antioxidant activities of M. citrifolia in the drying method of microwave power was the highest, followed by the heat pump and solar energy. Ethanol solvent was more effective than aqueous solvent as extracting bioactive substances (flavonoids content and polyphenol content).
 Conclusion: The results will be useful for preparing the dried M. citrifolia to serve for the storage and the produce of M. citrifolia in functional food and pharmaceuticals.

Effects of Various Drying Methods on Selected Physical and Antioxidant Properties of Extracts from Moringa oliefera Leaf Waste

This study aims to evaluate the effects of different drying methods on the physical properties, total phenolic content, total flavonoid content, and antioxidant activity of extracts from Moringa oliefera L. (MO) leaf waste. The effects of two drying techniques, namely, sun drying (A1) and tray drying (A2), on the physical and antioxidant properties of the extracts obtained using three extracting solvents, i.e., water (b1), ethanol (b2), and ethyl acetate (b3), were investigated. These extracts were analyzed for their physicochemical and antioxidant properties. The antioxidant properties were determined with the Folin Ciocalteau, aluminum chloride, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. Fourier transform infrared spectrophotometry (FTIR) was used to identify functional groups in the active compounds. It was found that the physical properties of the MO extract, including yield, pH, total solids, and color, showed significant differences for the two drying methods (p < 0.05). The b3 extract had the highest value for total phenolic contents, total flavonoid contents, and antioxidant activities, followed by b2 and b1, respectively, for both the sun drying and tray drying methods. There was a significant correlation between the total phenolic and flavonoid contents and antioxidant activity (IC50). This study reveals that waste material from MO leaves could be utilized as an antioxidant agent, which is expected to reduce environmental pollution from the MO processing industry.

Effects of Various Drying Methods on Physicochemical Characteristics and Textural Features of Yellow Croaker (Larimichthys Polyactis).

The physicochemical characteristics and textural properties of yellow croaker treated by hot air drying (HAD), low temperature vacuum drying (LVD), and freeze drying (FD) methods were studied. The dried fish by LVD had the lowest moisture content and highest protein. The volatile basic nitrogen values of dried fish by HAD, LVD, and FD were 66.27, 34.38, and 33.03 mg/100 g sample, respectively. The predominant amino acids of dried fish treated by LVD and FD were lysine, taurine, alanine, and glutamic acid, and the predominant ones by HAD were the remaining amino acids analyzed in this study, except lysine, taurine, alanine, and glutamic acid. By using the color parameters, the L* and b* values by LVD showed light brown and yellow colors of the fish. The textural properties of dried fish by LVD were softer and more chewable than those of HAD and FD. In the stereo-micrographs, the flesh of dried fish by LVD compared to others showed minimization of texture damage, resilient tissues, much fish oil, and were light brown in color. Taken together, these results suggest that LVD rather than HAD and FD provide good qualities of dried fish in terms of physicochemical characteristics and textural properties.

Effects of Various Drying Methods on Some Physico-Chemical Properties and the Antioxidant Profile and ACE Inhibition Activity of Oyster Mushrooms (Pleurotus Ostreatus).

In food biotechnology, Pleurotus ostreatus is of great interest as a source of natural antioxidants and angiotensin-converting enzyme (ACE) inhibitors. However, research in this area has not yet been completed. The effect of various drying methods on the structural properties and the rehydration capacity of mushrooms was investigated in this paper. The content of secondary metabolites, the peptide profile, and the antioxidative effect and ACE inhibitory activity of dry mushrooms were investigated in vitro, simulating the process of gastrointestinal digestion. X-ray microtomography has confirmed that structure of lyophilic and sun-dried mushrooms is dominated by open pores, and in mushrooms dried with hot air and microwave, closed pores. Experiments have shown that the conditions of freeze drying and sun drying of Pleurotus ostreatus provide a higher rehydration capacity of dried mushrooms. The maximum activity of radical absorption of the oyster mushroom after microwave drying was observed. The iron restoring capacity of the mushrooms is maximally maintained with microwave drying and hot-air drying. The properties of the antioxidant product with an emphasis on the high activity of inhibiting lipid oxidation of the mushroom maximized after drying in the sun. Mushrooms dried lyophilically and in the sun showed the highest ACE inhibitory activity.

Nutritional Composition of Plantain Flour of ( Musa Paradisiaca ): the Effect of Various Drying Methods in Rwanda

This research was conducted to determine the nutritional composition of plantain flour processed using three drying methods namely sun drying, oven drying, and microwave drying. A variety of Musa paradisiaca grown in Rwanda and locally named “inshakara” was peeled, sliced, dried and ground. Vitamin C, pro-vitamin A, and proteins of both fresh and flour samples were determined to examine possible losses of nutrients due to drying. Moisture content was also analyzed for the fresh sample only. The results found were 70.59%, 72.3% and 74.05% moisture loss due to sun, oven and microwave drying respectively. 6.45mg of vitamin C was determined in the fresh sample while 4.808mg, 4.156mg and 3.875mg of ascorbic acid were found in flour processed by sun drying, oven drying, and microwave drying respectively. The results obtained for s-carotene determination were 5.674µg for the fresh sample, 5.546µg for microwave dried plantain flour, 3.215µg for sun-dried plantain flour and 2.17µg for oven dried plantain flour. Proteins resulted in 1.8712% fresh sample, 1.1786% sun dried plantain flour, 1.3266% oven dried plantain flour and 0.9851% microwave dried plantain flour. The losses of nutrients varied due to the drying system applied.

Effect of Various Drying Methods on the Volatile Oil Composition of Basil Leaves

This article presents the results pertaining to the drying behavior of basil leaves (Ocimum basilicum L.) in natural air drying (~25-30°C, 2 days), hot-air drying (50°C, 6h, 1m/s), and vacuum drying (50°C, 8kPa, 7h) conditions. This study focused on the chemical composition characteristics of essential oils extracted from fresh and different dried basil leaves. The results showed that drying methods had a significant effect on essential oil content and composition of basil leaves. The volatile oil found in herbs is very sensitive to some drying parameters (e.g. pressure, temperature, weather, non-uniform drying, etc.). The quality of the vacuum dried product was assessed – from a twelve major constituents – as being higher than that of a hot-air dried and natural air dried products. Taking into account all these considerations we recommend the drying of basil leaves by vacuum drying.

Effect of Various Drying Methods on Flavor Characteristics and Physicochemical Properties of Dried Curry Leaves (Murraya koenigii L. Spreng)

Curry leaves (Murraya koenigii. L. Spreng) dried using microwave, combo (combination of microwave and convection), infrared (IR), inert gas, hot air oven, cross-flow tray, freeze drying, and the effect of drying on flavor and quality characteristics such as chlorophyll analyzed by spectrophotometry and Ca, Fe, Mg, Cu, Na, K, and Zn by atomic absorption spectrophotometry (AAS) were compared with sun and shade drying along with fresh leaves. Clevenger hydrodistillation indicated that the shade-dried leaves (1.34%) retained a higher amount of essential oil followed by microwave-dried leaves (1.06%). About 65 components were identified by gas chromatography–mass spectroscopy (GC-MS) analysis and microwave drying retained a comparatively greater number of volatiles followed by combo-, IR-, and inert gas–dried samples. β-caryophyllene, E-β-ocimene, and italicene ether were found in all of the dried samples but in variable proportions.