جستجوی مقالات مرتبط با کلیدواژه « Drying Methods » در نشریات گروه « صنایع غذایی »

In the present study, the effect of drying methods on the bioactive compounds of the two salvia spieces,Salviaofficinalis  andsalvia nemorosa,was investigated. The experiment was performed as a factorial experiment with two factors in a randomized complete block design with three replications. The first factor was two species of salvia and the second factor was drying method in 4 levels of shade drying for 144 hours, drying under the sun irradiation for 78 hours and drying in oven at 40 and 70°C for 37 and 6 hours, respectively. With concidering two levels for the first factor and four levels for the second factor, 8 treatments were studied in the experiment. The results showed that the highest extract yield (11%) was obtained from samples which dried in the oven with 70°C and in both species with a higher rate inS.nemorosa. The percentage of weight loss was not affected by drying methods but it affected by species andS.officinalis had the highest weight loss compared to another specie. High value of total phenolic compounds, total flavonoids, total tannin and antioxidant properties of two speiceswere found in samples dried in shade, and the lowest value of these traits were recorded in plants which dried in the oven at 70°C. High contents of phenolic acids including chlorogenic acid, caffeic acid, rosmarinic acid and salvainolic acidwere recorded  in both species which dried at shade condition and the lowest amount were found in samples dried in oven at 70°C. Also, salvainolicacid and rosmarinic acid was recorded at high level of phenolic acids in samples dried at shad condition.By comparing breeded (S. officinalis) and native species (S. nemorosa), it was found that the native species can have outstanding features for domestication, improvement and further research.

The post-harvest techniques of medicinal plants such as drying, is very important in their production cycle. The present study was carried out to evaluate the effect of different drying methods on some phytochemical traits of Chuchak in the spring of 2020 based on the completely randomized design with three replications. The chuchak samples were collected in the vegetative stage from the gardens of Noor city, Iran. The drying treatments were shade-drying at room temperature (25±3 °C), sun-drying, oven-drying (45, 55 and 65 °C), vacuum oven-drying (45, 55 and 65 °C), microwave-drying (200, 500 and 800 watts), and fresh samples. The studied traits were moisture content based on fresh and dry weight, drying time and speed, ascorbic acid content, protein content, total carbohydrate content, total phenol and flavonoid content and antioxidant activity. The results of the variance analysis showed the significant effect of drying methods on all studied properties of the samples (P≤0.01). The mean comparison showed that the minimum drying time and the maximum speed drying were related to the microwave (800 watts). The highest amount of ascorbic acid (385.72 µg/mg), protein (19.72%), total phenol (47.19 mg GA per 1 g dry matter), total flavonoids (50.96 mg quercetin per 1 g dry matter) as well as antioxidant activity (76.02%) was observed in the fresh plant and then in the oven-drying (55 °C).

The drying process plays an important role in the treatment of medicinal plants, in order to maintain the quantity and quality of the essential oil extracted from the plant. Because Medicinal herbs containing essential oils If they are not dried immediately or their essence is not extracted, they will lose their active ingredients and volatile compounds.The aim of this study is design a hybrid dryer to drying medicinal plants and comparison their results with traditional drying methods (sun and shade).The effects of different drying methods (hybrid dryer, oven and shade drying) on the essential oil content and chemical composition of thyme were studied. The essential oils from each organ type were extracted by hydrodistillation and the chemical components were analyzed by GC/MS systems. Mathematical modeling results showed that the Midilli model can fit the drying curves with high accuracy. The highest essential oils yield of 2.4 % (v/w) was obtained by a hybrid dryer. Results indicated that hybrid dryer could keep the 24 Kinds of volatile compounds of Thymus while these values were 10 and 6 for oven and shadow methods, respectively. The main components of the essential oils in different drying methods were including alpha and beta pinene, caryophyllene, caryophyllene oxide, carotol, thymol, thymol methyl ether, terpinene-4-ol, gama-terpinene, p-cymene.In general, hybrid drying method is recommended as the best method for post-harvest thyme processing.