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

Author(s):  
Sonia Singh ◽  
Neetu Agrawal

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).

Author(s):  
Dyke Gita Wirasisya ◽  
Yohanes Juliantoni ◽  
Wahida Hajrin

The aim of this study was to determine a change that occurs in total phenolic content (TPC) and antibacterial activity of ashitaba (Angelica keiskei) after dried using two different methods : sun and oven drying. The effectiveness of the drying methods was evaluated in term of total phenolic content (TPC) by using spectrophotometric assay with Folin-Ciocalteu reagent and antibacterial activity againts Streptococcus mutans by in vitro macrodilution assay. Oven drying at 60oC possessed high TPC (2,98 ± 0,0935 g EAG/100g) compared to sun drying method (1,72 ± 0,0142 g EAG/100g). Simillar pattern was also observed in antibacterial activity. Oven drying have higher antibacterial activity with the MBC (minimal bactericidal concentration) value of 0,5 mg/mL againts Streptococcus mutans. Therefore, sun drying is not suggested for drying method of ashitaba in terms of total phenolic content and antibacterial activity compared with oven drying methods.


2020 ◽  
Author(s):  
Yuexing Chang ◽  
Junjie Lin ◽  
Siqing Pan ◽  
Yanlin Jing ◽  
Ailing Guo ◽  
...  

Abstract Background: Osmamthus fragrans (O. fragrans) has high ornamental, edible and medicinal value in China. The components of its flowers have been gradually revealed, but the active ingredients with immunoregulatory activity have been unknown. Also, it needs to be studied that which groups and drying methods can make O. fragrans fowers produce more immunomodulatory activity. This study aimed to investigate the effects of drying methods on non-volatile and volatile components of O. fragrans flowers from three groups, and to further explore if their groups and drying methods had an ovious effect on their immunoregulatory activity.Methods: O. fragrans flowers from three groups such as “Aurantiacus”, “Latifolius” and “Thunbergii” were dried with shade drying, sun drying, quick-lime drying, oven drying and microwave drying method, respectively. The non-volatile components such as salidroside, verbascoside, oleanolic acid and ursolic acid and volatile components such as linalool, linalool oxide, geraniol, α-ionone and β-ionone of O. fragrans flowers above were determined by high-performance liquid chromatography (HPLC) and gas chromatography (GC), respectively. The immunomodulatory activities of chemical components above were investigated by the neutral red uptake assay.Results: There are more non-volatile components and less volatile components in O. fragrans flowers from Aurantiacus group and Latifolius group than Thunbergii group. Microwave drying and oven drying at high temperature were beneficial for the preservation of the bioactive non-volatile components for killing enzyme and protecting glycoside. Other drying methods such as shade drying, sun drying, quick-lime drying and oven drying at low temperature were beneficial to their preservation of the fragrant volatile components. Salidroside, verbascoside, linalool, and linalool oxide had the better immunoregulatory activity than other ingredients. In addition, non-volatile components played a more important role in the contribution to the immunoregulatory activity than the volatile components as the former was almost 1000 times as much as the latter. Conclusions: O. fragrans flowers from Aurantiacus group with microwave drying (high fire) method had the best immunoregulatory activity. The research could provide some evidence in choosing drying method of O. fragrans flowers as food or medicine.


2018 ◽  
Vol 46 (2) ◽  
pp. 449-456 ◽  
Author(s):  
Hacer COKLAR ◽  
Mehmet AKBULUT ◽  
Semih KILINC ◽  
Ali YILDIRIM ◽  
Iliasu ALHASSAN

Flowers, leaves and fruits of hawthorn plant are traditionally used for treating diseases like hypertension and atherosclerosis. The medicinal effects of the plant are generally attributed to its phenolic compounds. However, the fruits are perishable materials because of their high content of water, and generally dried and stored to be used outside its season. The main aim of this research was to investigate the effect of different drying methods on phenolic compounds of the hawthorn fruit. Fruits were collected from the wild growing trees in Turkey. De-seeded fruits were dried in freeze-, oven- (60 oC) and microwave pretreated oven drying (microwave application for 5 min at 360 W before drying at 60 oC) methods and analyzed for antioxidant activity, phenolic compounds, total phenolic content and color parameters. Total phenolic content of fresh hawthorn fruits was found as 13.36 mg g-1 DW. Oven- and microwave pretreated oven drying methods had a reductive effect on total phenolic content and antioxidant activity of fruits when compared to freeze drying method. (-)-Epicatechin (994.10 mg kg-1 DW), rutin (765.30 mg kg-1 DW), and procyanidin B2 (553.80 mg kg-1 DW) were the main phenolics of the fruit. Lowest values of these three compounds were observed in oven-dried fruits. Microwave pretreatment oven drying method resulted in browner product. Although the highest phenolic concentration and antioxidant activity were occurred in freeze-dried sample, microwave pretreatment before oven drying could be applied to reduce the time and cost of drying in terms of phenolic compounds and antioxidant activity.


Author(s):  
Annu Kumari ◽  
Yeluru Mohan Babu ◽  
Eggadi Ramesh ◽  
Tshering Ongchu Lepcha ◽  
Suman Tamang ◽  
...  

Under the present investigation, ginger was produced at the instruction cum research plots of the Department of Plantation Crops and Processing, Faculty of Horticulture, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar, West Bengal. The experiment was laid out in a factorial CRD. The study was undertaken with four ginger varieties namely Gorubathan, Suprabha, Suruchi and Suravi to evaluate the effect of different drying methods (sun drying, hot air drying at 50OC, 60oC and 70oC and microwave drying on time required for drying to a moisture content of 8 – 10% and to chemical composition (essential oil, oleoresin content and crude fiber content) of the end product. Results shown that Gorubathan variety has the highest essential oil (2.243%) and oleoresin content (14.840%) among the four varieties in this study, highest crude fiber content (5.253%) was observed in Suprabha and highest dry recovery (25.77%) was obtained from Suravi variety. In hot air drying, with increase in temperature essential oil, oleoresin and crude fiber content in dry ginger as well as dry recovery reduced. With high dry recovery (25.77%), essential oil (2.037%) and oleoresin content (13.510%) and moderately low crude fiber content (4.637%), it can be concluded that Suravi variety is best suitable for producing dry ginger. Apart from microwave drying, sun drying can be recommended as better practice, when hygienically conducted, based on essential oil and oleoresin content.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yingpeng Tong ◽  
Xingyi Zhu ◽  
Yongqiu Yan ◽  
Ruoxi Liu ◽  
Feng Gong ◽  
...  

More and more saffron has been cultivated in China because of the increasing saffron demand, but no paper has studied the influence of drying methods on the quality of Chinese saffron. In this paper, three different dehydration treatments applied in actual production were evaluated: dehydration with electric oven, vacuum oven, and microwave. We determined that the highest quality of saffron will be obtained when fresh saffron is treated at higher temperatures (no more than 70°C) for a long time by electric oven drying and vacuum oven drying. In microwave drying, treatments at lower microwave power and longer time benefit the quality of saffron. In addition, the influence of the drying method on antioxidants in saffron is discussed. The correlation between individual saffron profiles and the antioxidant value was estimated by spectrum-effect relationships analysis.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 484 ◽  
Author(s):  
Dongyoung Lee ◽  
Santosh Lohumi ◽  
Byoung-Kwan Cho ◽  
Seung Hyun Lee ◽  
Hyunmo Jung

Drying kinetics and the moisture distribution map of radish slabs under different drying methods (hot-air drying (HAD), microwave drying (MD), and hot-air and microwave combination drying (HMCD)) were determined and visualized by hyperspectral image (HSI) processing coupled with a partial least square regression (PLSR)-variable importance in projection (VIP) model, respectively. Page model was the most suitable in describing the experimental moisture loss data of radish slabs regardless of the drying method. Dielectric properties (DP, ε ) of radish slices decreased with the decrease in moisture content (MC) during MD, and the penetration depth of microwaves in radish was between 0.81 and 1.15 cm. The PLSR-VIP model developed with 38 optimal variables could result in the high prediction accuracies for both the calibration ( R c a l 2 = 0.967 and RMSEC = 4.32 % ) and validation ( R v a l 2 = 0.962 and RMSEC = 4.45 % ). In visualized drying patterns, the radish slabs dried by HAD had a higher moisture content at the center than at the edges; however, the samples dried by MD contained higher moisture content at the edges. The nearly uniform drying pattern of radish slabs under HMCD was observed in hyperspectral images. Drying uniformity of radish slabs could be improved by the combination drying method, which significantly reduces drying time.


Author(s):  
Manhal Gobara Hamid ◽  
Abdel Azim Ahmed Mohamed Nour

PurposeThe purpose of this paper is to evaluate the effect of different drying methods on quality attributes of beetroot slices.Design/methodology/approachThree drying methods (sun, oven and freeze-drying) were applied to dry fresh slices of beetroot cultivar (Beta vulgaris). The chemical composition, minerals, nitrate, betalains, total phenolic, total flavonoid and color were measured for fresh and dried slices.FindingsThe chemical composition, minerals, nitrate, bioactive compounds and color were measured for fresh and dried slices. Regardless of the drying method, the results showed that the chemical composition, total energy, minerals and nitrate of the dried slices were significantly (p=0.05) increased compared to that of fresh slices. Sun and oven drying of the slices significantly (p=0.05) reduced total betalain and betacynin. However, betaxanthin was significantly (p=0.05) increased. Total phenolics content of fresh beetroot was significantly (p=0.05) increased after sun and oven drying but total flavonoids were decreased. The 2,2,-diphenyl-2-picryl-hydrazyl (DPPH) of fresh beetroot was increased significantly (p=0.05) after sun and oven drying. The measurement of the color of the powder showed that there is a decrease in lightness (L) depending on the drying method applied. A maximum reduction in lightness was observed in powder of sun-dried slices. The color of the powder obtained from freeze-dried slices was stable compared to other drying methods.Practical implicationsBeetroot is a rich source of nutrients but with short shelf life. Dried beetroot has more keeping quality than the fresh one.Originality/valueThe study uses beetroot as a rich source of nutrients as well as natural antioxidant source. Betalain compounds are preserved in beetroot and a high source of phenolics and flavonoids. Flavonoids are a group of phenolic products of plant metabolism with high antioxidant properties to protect against diseases without side effects.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1378
Author(s):  
Yousef Abbaspour-Gilandeh ◽  
Mohammad Kaveh ◽  
Hamideh Fatemi ◽  
José Luis Hernández-Hernández ◽  
Alejandro Fuentes-Penna ◽  
...  

This study aims to investigate the effect of different drying methods on the thermal, qualitative, and antioxidant properties and pH of terebinth. To perform the experiments in this study, the hot air (HA), infrared (IR), microwave (MW), hot air–infrared (IR–HA), and hot air–microwave drying (MW–HA) methods were considered. The results showed that the minimum drying time was obtained by the hot air–microwave (MW–HA) method. However, the lowest specific energy consumption (SEC) and the highest energy efficiency (ηe) were obtained by the MW method. Considering the color criteria, the best method was obtained by the MW–HA method. The highest amount of rehydration ratio (RR) and the lowest shrinkage (Sb) of the dried terebinth samples were obtained using the MW dryer compared with other drying methods. The MW and MW–HA methods resulted in higher contents of total phenol content (TPC), total flavonoid content (TFC), and antioxidant capacity (AntiOX) than other methods. According to the results of this study, the most effective drying method for terebinth was determined to be the MW and MW-HA methods.


Author(s):  
Ala eddine Derardja ◽  
Malika Barkat

Background: The indubitable role of phytochemicals such as carotenoids and phenolic compounds in human health has prompted the researchers to study the factors affecting the stability and the availability of these compounds. Aims: This study investigates the effect of two drying processes; oven-drying (OD) and traditional sun-drying (TSD) on carotenoids and phenolic compounds of apricots. Material and Methods: OD was performed at 65°C, and TSD was performed by direct exposure of apricot to sunlight at daytime temperatures around 40°C and relative humidity between 25 and 35%, following an Algerian traditional method of drying. Carotenoids and phenolic compounds were extracted, and then total carotenoids (TC), total phenolic compounds (TPC), total flavonoids (TF) and total tannins (TT) were spectrophotometrically quantified. The free radical scavenging activity (FRSA) of the phenolic extracts was measured by the DPPH method. Results: Carotenoids and phenolic compounds were significantly affected by both drying methods. OD decreased TC and TT by 44% and 12%, respectively, and increased TPC and TF by 4%. TDS affected negatively all the measured components, where TC, TPC, TF, and TT decreased by 67%, 15%, 43%, and 36%, respectively. However, the highest FRSA was reported for the TSD apricots (40%) followed by OD apricots (36%), and fresh apricots (32%). Conclusions: The effect of drying on apricot antioxidants depends on the applied drying method and the studied component. The direct sunlight exposure and the duration of drying condemned TSD to be more harmful on carotenoids and phenolic compounds compared to OD, where carotenoids where more fragile during TSD. In addition, OD improved the content of phenolic compounds by improving their extractability. However, TSD apricots seem to be a better source of free radical scavenging compounds. Keywords: Apricot, traditional sun-drying, oven-drying, carotenoids, phenolic compounds.


2021 ◽  
Vol 8 ◽  
Author(s):  
Youyuan Lu ◽  
Xiangfeng Kong ◽  
Juanhong Zhang ◽  
Chao Guo ◽  
Zhuo Qu ◽  
...  

The fruit of Lycium ruthenicum (LRF), known as black wolfberry, is a medicinal and edible fruit. The fresh LRF is perishable and has only about 3 days of shelf life. Drying could prolong the shelf life of LRF. However, it could imply physical changes and chemical modification. This study evaluated the effect of sun drying (SD), hot air drying (HD), and freeze drying (FD) on the appearance characteristics, moisture content, bioactive compounds, amino acid composition, and antioxidant activity of LRF. The results showed that LRF dried by FD was round, expansive, fragile, and maintained the largest amount of appearance traits among the three drying methods. Drying methods had a significant effect on phytochemical content and antioxidant activity of LRF (P < 0.05). Principal component analysis (PCA) showed that procyanidin content (PAC), asparagine (Asn), total phenolic content (TPC), total anthocyanin content (TAC), and moisture content were the main sources of the difference in LRF dried by different methods. The characteristic of LRF in FD was low moisture content, and high TPC, Asn, PAC, and TAC. Sun drying was opposite to FD. Hot air drying was high TPC and low TAC content. The quality of LRF was in the order of FD > HD > SD based on comprehensive evaluation of the phytochemical component content and antioxidant capacity. Additionally, the water temperature and soaking time had different antioxidant activity effect on LRF dried by different methods. These findings will provide useful information for production and utilization of LRF.


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