Comparative analyses of phenolic composition, antioxidant capacity, and color of cool season legumes and other selected food legumes

ABSTRACT:  The objective of this study was to characterize the phenolic compounds and antioxidant activities of U.S.-produced cool season legumes. A total of 33 cool season legume samples were selected. Some common beans and soybeans were included for comparisons. Total phenolic content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) were analyzed. Ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, and oxygen radical absorbance capacity (ORAC) were used for analyzing antioxidant properties. Color of the legume flour and the seed coat was also analyzed. TPC, TFC, CTC, FRAP, DPPH, and ORAC values of legumes were significantly different not only between classes but also among samples within each class. Among cool season legume classes, lentils possessed the highest concentrations of the phenolic compounds and antioxidant activities. Colored common beans and black soybeans exhibited higher TPC, TFC, CTC, FRAP, DPPH, and ORAC values than those of yellow peas, green peas, and chickpeas. Antioxidant activities (FRAP, DPPH, and ORAC) were strongly correlated ( r = 0.96, 0.94, and 0.89, respectively, P < 0.01) with TPC. TPC and ORAC were moderately correlated ( P < 0.01) with either the seed hull surface color or the flour color.     

蓝莓花、茎、叶酚类物质含量及抗氧化活性比较

比较蓝莓花、嫩茎、嫩叶及老叶总多酚、总黄酮、原花青素的含量,并研究其抗氧化性能差异。结果表明:嫩叶中总多酚含量最高,为43.77 mg GAE/g(以干质量计,下同),分别是花、嫩茎和老叶的3.45、1.42、1.12倍;老叶中总黄酮、原花青素含量最高,为68.01 mg RE/g、23.29 mg CAE/g,分别是花的2.57倍和4.61倍、嫩茎的1.79倍和1.23倍、嫩叶的1.03倍和1.98倍。抗氧化性能中,老叶的铁还原能力最大,其次是嫩茎和花,嫩叶较差;清除·OH的能力为嫩茎嫩叶花老叶;清除DPPH自由基能力和总抗氧化能力均为嫩茎嫩叶老叶花甲醇提取物,均高于对照品;蓝莓各部分提取物对DPPH自由基的清除能力最强,总抗氧化能力次之,清除·OH能力和铁还原能力较差。     

Characterisation and comparison of phenols,flavonoids and isoflavones of soymilk and their correlations with antioxidant activity

To investigate the relationship between bioactive compounds and antioxidant property, total phenolic content (TPC), total flavonoid content (TFC), individual and total isoflavone content of soymilk and their correlations with oxygen‐radical‐absorbing capacity (ORAC), ferric reducing antioxidant power (FRAP) and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging capacity values were evaluated and compared. Results showed that TPC, TFC, isoflavones (including concentration and profiles) and antioxidation activity significantly varied among ten tested soybean cultivars. Significant correlations were established between DPPH and TFC (r = 0.553, P < 0.01), DPPH and TPC (r = 0.753, P < 0.01), FRAP and TFC (r = 0.599, P < 0.01) and FRAP and TPC (r = 0.616, P < 0.01). Positive linear correlations were found between subtotal, total isoflavones and ORAC. Unlike other isoflavone monomers, aglycone isoflavones correlated positively with DPPH and FRAP significantly. DPPH well correlated with FRAP, whereas neither DPPH nor FRAP correlated with ORAC. TPC, TFC, individual and total isoflavone values are potentially useful for soymilk antioxidant activity assessment.     

丝瓜花不同溶剂提取物抗氧化活性及其酚类成分分析

以无水乙醇、70%乙醇、40%乙醇和水分别对丝瓜花进行提取,并测定各提取物中总酚、总黄酮含量,采用DPPH·清除能力、超氧化物自由基清除能力、FRAP抗氧化能力和亚铁离子螯合能力等方法评价其抗氧化活性,通过HPLC分析其中酚类成分。结果表明,70%和40%乙醇提取物总酚及总黄酮含量较高,而且DPPH·清除活性、FRAP还原力最强,40%乙醇提取物、水提物分别具有最强的超氧阴离子自由基清除活性和亚铁离子螯合能力。总酚含量与DPPH·清除活性之间存在较强的相关性(R²=0.8688)。HPLC分析检出提取物中9种酚类化合物,其中含量最高的为杨梅素。试验结果说明,70%乙醇、40%乙醇可能是丝瓜花抗氧化性物质提取的较好溶剂。结果表明丝瓜花是一种较好的抗氧剂资源。     

Antioxidant activities of aqueous extracts of selected plants

The antioxidant properties of 25 edible tropical plants, expressed as Trolox equivalent antioxidant capacity (TEAC), were studied using DPPH (1,1-diphenyl-2-picrylhydrazyl free radical) scavenging and reducing ferric ion antioxidant potential (FRAP) assays. Their cupric ion chelating activities (CCA) and total polyphenol contents (TPC) were also determined. A strong correlation between TEAC values obtained for the DPPH assay (TEAC_DPPH) and those for the FRAP assay (TEAC_FRAP) implied that compounds in the extracts were capable of scavenging the DPPH free radical and reducing ferric ions. A satisfactory correlation of TPC with TEAC_DPPH and TEAC_FRAP suggested that polyphenols in the extracts were partly responsible for the antioxidant activities while its correlation with CCA was poor, indicating that polyphenols might not be the main cupric ion chelators. Principal component analysis (PCA) indicated that TEAC_DPPH, TEAC_FRAP and TPC contributed to the total variation in the antioxidant activities of the plants.     

Rapid Determination of Antioxidant Compounds and Antioxidant Activity of Sudanese Karkade (<Emphasis Type="Italic">Hibiscus sabdariffa</Emphasis> L.) Using Near Infrared Spectroscopy

The extraction conditions applied in destructive analysis of Hibiscus sabdariffa L. (Hs) matrices before the measurement of antioxidant compounds may reduce their activities during isolation and purification due to decomposition. Hence, near infrared spectroscopic system was applied to determine these compounds. The calibration models developed by using partial least squares regression (PLSR) with 48 Hs samples and 24 unknown samples were used to confirm the robustness of the developed model. The results of calibration models effectively allowed the determination of the concentrations of total phenol content (TPC), total flavonoid content (TFC), total antioxidant content (TAC), ferric reducing antioxidant power (FRAP), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) with high correlation coefficients (0.85–0.91) and small standard error of cross-validation (RMSECV) ranged from 0.08 to 0.33. The prediction capacity (RPD) for TPC, TFC, TAC, FRAP, and DPPH ranged from 3.30 to 8.25, thus demonstrating that the near infrared spectroscopic (NIRS) equations developed were applicable to unknown samples. This study demonstrates that NIRS can be considered as a fast tool for the nondestructive determination of antioxidant compounds (phenolics and flavonoids) and antioxidant activity of the Hs.     

Extraction and application of antioxidants from black glutinous rice

This research aimed to determine optimum extraction condition of black glutinous rice crude extract and to determine its application as an antioxidant in fish oil enriched mayonnaise. Black glutinous rice flour was extracted twice with 70:30 acetone-water mixture (v/v) at pH 2 and 6.8 for 2, 4 and 8 h of total extraction times. Total phenolic content (TPC), total monomeric anthocyanin content (TMA) and antioxidant activities as determined by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assays of the crude extracts were measured. The extraction with pH 6.8 solvent for 4 h yielded the crude extract with significantly highest antioxidant activities analyzed by both FRAP and DPPH tests (p ≤ 0.05) although its TPC and TMA were not greatest. The freeze-dried extract from this condition was then added into fish oil enriched mayonnaise at 500 mg/kg and 1000 mg/kg (oil weight basis). Conjugated diene hydroperoxides (CDH), thiobarbituric acid reactive substance (TBARs) and color in CIELAB system of the mayonnaise samples stored at 30 °C were determined up to 30 days. The samples contained 1000 mg/kg crude extract had lowest rate of CDH and TBARs increase but had greatest extent of color deterioration, possibly due to anthocyanin degradation and Maillard reaction.     

Polyphenols content and antioxidant capacity of thirteen faba bean (Vicia faba L.) genotypes cultivated in Tunisia

In vitro antioxidant capacity of thirteen genotypes of faba bean (Vicia faba L.) collected during three different growing stages (vegetative, reproductive and maturity) have been evaluated. For the vegetative stage (VS) and reproductive stage (RS) the whole plant (WP) has been used for the analysis while for the maturity stage (MS) the plant was divided and analyzed in different parts, the whole seed (WS), seed coat (SC), cotyledons (Cot) and pod (Pod). The antioxidant capacity has been evaluated by means of the total phenolic and total flavonoid contents (TPC and TFC respectively), the ferric-reducing/antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assays. The results showed different antioxidant properties for the same genotype when considering the different parts or stages of the plant. High content of both total phenolics (> 92.85 mg as gallic acid equivalent (GAE)/g of dried plant) and flavonoids contents (> 11.87 mg as rutin equivalent (RE)/g of dried plant) were found for all genotypes during the vegetative and the reproductive stages, which also showed the highest antioxidant activity (FRAP value ≥ 1.157 mmol/g and DPPH radical-scavenging capacity > 43.49%), indicating their potential as natural sources of antioxidant foods. For the maturity stage, the highest values for the TPC, TFC, FRAP and DPPH scavenging capacity were observed for the pods and the lowest for the cotyledons.The results of this study indicate that faba beans are a good source of natural antioxidants independently to their genotype. The quantification of the antioxidant capacity according to the stage and the plant part could be suitable for applications on the food industry in relation to production and preservation of faba bean food products.     

Antioxidant activity and phenolic content of pressurised liquid and solid–liquid extracts from four Irish origin macroalgae

The efficiency of solid–liquid extraction (SLE) and pressurised liquid extraction (PLE) for the recovery of antioxidant and polyphenols from the Irish macroalgae, Fucus serratus, Laminaria digitata, Gracilaria gracilis and Codium fragile, was assessed using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays and the Folin–Ciocalteu total phenol content (TPC) assay. Fucus serratus had TPC and antioxidant activities thirty times higher than the other species. Solid–liquid extraction cold water (CW_SLE) had the highest TPC (81.17 μg GAE mg^?1 sample) derived from F. serratus, compared with the TPC of 61.12 μg GAE mg^?1 sample for the corresponding PLE extract. For both SLE and PLE extracts, low TPC levels were observed in L. digitata, G. gracilis and C. fragile. The majority of SLE extracts possessed higher FRAP and DPPH activities compared with their PLE counterparts. This study indicates that the high temperatures and pressures in PLE did not enhance the antioxidant activities relative to conventional SLE extraction.     

Physicochemical,functional and antioxidant properties of flour from pearl millet varieties grown in India

Indian pearl millet varieties were selected, milled to flour and studied for their proximate composition, hunter color, functional, and antioxidant properties. Proximate composition and hunter color values differed significantly (p < 0.05) among varieties. Hunter L* value was found the highest for HHB-223 flour whereas a*, b* and ΔE was the highest for W-445 flour. Flours also showed significant variations in their total phenolic content (TPC), total flavonoids content (TFC), antioxidant activity (DPPH) and metal chelating activity. Variety GHB-732 showed the highest values for TPC (3137 µg GAE/g) and DPPH (46.7 %) activity. TFC was, however, found the highest for HC-10 (2484 µg CE/g) variety. Several significant correlations were observed among different flour properties as revealed by both pearson correlations and principal component analysis. Formulation of chapatti resulted in decrease in TPC, TFC, DPPH values when compared to its flour. However, reverse was observed for metal chelating activity.     

A comparative assessment of total phenolic content,ferric reducing-anti-oxidative power,free radical-scavenging activity,vitamin C and isoflavones content in soybean with varying seed coat colour

Reports concerning anti-oxidative properties of yellow, green and black soybean seeds available in the literature are insufficient and limiting. In the present investigation, mature seeds of 18 genotypes, 6 from each type of soybean i.e. yellow, green and black, were assessed for total phenolic content (TPC), ferric reducing-anti-oxidative power (FRAP), 2,2-diphenyl-1-picrylhydrazine (DPPH) free radical-scavenging activities (FRSA). Isoflavones and vitamin C, the antioxidants, were also determined in all the soybean genotypes. Significant genotypic variation was observed for TPC, FRAP, FRSA, isoflavones and vitamin C within each type of soybean. Maximum genotypic variation (7.27-fold) was observed for TPC in black soybean. Average FRAP value of yellow soybean was significantly (p < 0.05) lower than black and green soybeans. Average FRSA in black soybean was significantly higher than yellow and green soybean group. Average total phenolic content and isoflavones levels were not significant across different types of soybean. Correlation studies indicated significant (p < 0.05) positive correlation between FRSA and TPC in black soybean. Our results suggest that antioxidant constituents other than isoflavones contribute significantly to the FRSA in black soybean genotypes.     

A comparative study on phenolic profiles and antioxidant activities of legumes as affected by extraction solvents

ABSTRACT:  The objective of this study was to investigate how 6 commonly used solvent systems affected the yields of phenolic substances and the antioxidant capacity of extracts from 8 major classes of food legumes. Several antioxidant-related phytochemical compositions, namely, total phenolic content (TPC), total flavonoids content (TFC), and condensed tannins content (CTC), were investigated. In addition, antioxidant activities were tested using 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging, ferric-reducing antioxidant power (FRAP), and the oxygen radical absorbance capacity (ORAC). The results showed that the 50% acetone extracts exhibited the highest TPC for yellow pea, green pea, chickpea, and yellow soybean. Acidic 70% acetone (+0.5% acetic acid) extracts exhibited the highest TPC, TFC, and FRAP values for black bean, lentil, black soybean, and red kidney bean. The 80% acetone extracts exhibited the highest TFC, CTC, and DPPH-free radical scavenging activity for yellow pea, green pea, chickpea, and yellow soybean. The 70% ethanol extracts exhibited the greatest ORAC value for all selected legumes. These results indicated that solvents with different polarity had significant effects on total phenolic contents, extracted components, and antioxidant activities. High correlations between phenolic compositions and antioxidant activities of legume extracts were observed. The information is of interest to the nutraceutical food/ingredient industries since legumes are a rich source of antioxidants.     

Evaluation of antioxidant,antibacterial and anti-tyrosinase activities of four Macaranga species

The methanolic fresh leaf extracts of Macaranga gigantea, Macaranga pruinosa, Macaranga tanarius and Macaranga triloba were screened for their antioxidant properties (AOP), tyrosinase inhibition and antibacterial activities. Total phenolic content (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, ferric-ion reducing power (FRAP), ferrous-ion chelating (FIC) and lipid peroxidation inhibition (LPI) activities were used to evaluate the AOP. Modified 3,4-dihydroxy-L-phenylalanine (L-DOPA) method was used to determine tyrosinase inhibition activity, whereas antibacterial activity was determined using the disc-diffusion technique. TPC screening of the same species from different collection sites showed no significant difference between sites. M.triloba showed the highest ascorbic acid equivalent antioxidant activity (AEAC), FRAP and LPI values. M. tanarius, which showed the lowest TPC, AEAC, FRAP and LPI activities, exhibited the best FIC activity. M. pruinosa showed the best tyrosinase inhibition activity, whereas M. triloba showed the best antibacterial activity against Gram-positive bacteria species, with minimal inhibition dosage (MID) values as low as 10 μg/disc.     

Antioxidant and Free Radical Scavenging Capacity of Extensively Used Medicinal Plants in Sri Lanka

The burden of chronic diseases is rapidly increasing worldwide. Diet and nutrition are important factors in the promotion and maintenance of good health throughout the entire life course. Physiological and biochemical alterations in the human body may result in overproduction of free radicals leading to oxidative damage to biomolecules (e.g. lipids, proteins, DNA). Use of medicinal plant based products has increased recently because of their exerted beneficial properties such as antioxidant, anticancer, hypoglycaemic and hypolipidaemic activities. The present study was designed to assess the in vitro antioxidant activity and free radical scavenging capacity of ten medicinal plants which are extensively used in the Ayurvedic treatment systems in Sri Lanka. Water extracts were prepared and evaluated for their free-radical scavenging capacity and antioxidant activity using a number of chemical assays; DPPH, ABTS and FRAP. The total Phenolic (TPC) and Total Flavonoid Content (TFC) were also assessed. The TPC and TFC values of the extracts varied from 295.94±3.65 – 5.22±0.08 (mg Gallic Acid Equivalent (GAE)/g dry weight) and 115.01±1.69 – 0.97±0.002 (mg Catechin Equivalent (CE)/g dry weight) respectively. The DPPH and ABTS radical scavenging activities were higher for the Nelli (Phyllanthus emblica) extract while the least activity was observed in Venivel (Cosciniumfenestratum) extract. The FRAP activity of the extracts was well proved with the DPPH and ABTS radical scavenging activities. A positive, significant linear relationship between antioxidant activity and TPC and TFC content showed that phenolic compounds and flavonoids were the dominant antioxidant components in the medicinal herbs studied.     

Camel milk lactoferrin reduces the proliferation of colorectal cancer cells and exerts antioxidant and DNA damage inhibitory activities

Lactoferrin (Lf), the main iron-binding protein of milk, has biological activities. We have evaluated the potential of camel milk lactoferrin for its ability to inhibit the proliferation of the colon cancer cell line, HCT-116, in vitro, DNA damage and its antioxidant activities for the first time. The antioxidant capacity of Lf was evaluated by different assays, including ferric-reducing/antioxidant power assay (FRAP), free radical-scavenging activity (DPPH), nitric oxide (NO) radical-scavenging assay, total antioxidant activity and DNA damage, compared with vitamin C and rutin.     

Antioxidant capacity,total phenolics,glucosinolates and colour parameters of rapeseed cultivars

The antioxidant capacity of twenty nine rapeseed varieties was determined by using ferric reducing antioxidant power (FRAP) and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) methods. Mean FRAP (3190–6326 μmol Trolox/100 g) and DPPH (3194–6346 μmol Trolox/100 g) values for methanolic extracts of rapeseed cultivars did not differ significantly. Moreover, the total content of phenolics (756–1324 mg sinapic acid/100 g), glucosinolates (4.2–87.5 μmol/g, respectively), erucic acid (0.0–56.1%) and colour parameters of the studied rapeseed cultivars were analysed. Antioxidant capacity determined by FRAP and DPPH methods correlated significantly with total phenolic content (TPC) in rapeseed cultivars (r = 0.9332, 0.9339, p < 0.001). Also, significant, inverse correlations were found between antioxidant capacity, total phenolics and luminosity (L^∗) or red colour intensity (a^∗) of rapeseed cultivars. Principal component analysis (PCA) allowed the rapeseed varieties to be differentiated based on their antioxidant capacities, total amounts of phenolics, glucosinolates, erucic acid and colour parameters.     

Assessment of antioxidant capacity of sedum (<Emphasis Type="Italic">Sedum sarmentosum</Emphasis>) as a valuable natural antioxidant source

In order to investigate the antioxidant capacity of sedum (dolnamul, Sedum sarmentosum) and to offer a scientific basis for the medicinal use of it, lyophilized sedum leaves were extracted with n-hexane, n-butanol, ethyl acetate, and methanol, respectively. The methanol extract (ME) showed the highest extraction yield, but no significant differences in the extraction yield were observed. The total polyphenol content (TPC) of the ethyl acetate extract (EAE) and the ME was significantly higher than that of the non-polar solvent extracts. The EAE and ME showed the superior antioxidant activities in the DPPH, oxygen radical absorbance capacity (ORAC), and ferric reducing ability of plasma (FRAP) assays. Lipid peroxidation was efficiently inhibited by the addition of the sedum extracts in the ferric thiocyanate (FTC) and thiobarbituric acid reactive substances (TBARS) assays, but significant differences among the tested extracts were not observed. The ME showed the potent lipid peroxidation inhibitory activity comparable to butylated hydroxytoluene (BHT). The correlations between the TPC and the antioxidant activities based on the DPPH, ORAC, and FRAP assays were highly positive (R ²>0.899).     

Determination of total phenolic content and antioxidant capacity of onion (Allium cepa) and shallot (Allium oschaninii) using infrared spectroscopy

Total phenolic content (TPC) and total antioxidant capacity (TAC) of four onion varieties (red, white, yellow and sweet) and shallot from selected locations (Washington, Idaho, Oregon, Texas and Georgia) were determined using Fourier transform infrared (FT-IR) spectroscopy (4000–400 cm⁻¹). The Folin–Ciocalteu (F–C) assay was used to quantify TPC and three assays were used to determine TAC, including 2,2-diphenyl-picrylhydrazyl (DPPH) assay, Trolox equivalent antioxidant capacity (TEAC) assay and ferric reducing antioxidant power (FRAP) assay. Partial least squares regression (PLSR) with cross-validation (leave-one-out) was conducted on onion and shallot extracts (n = 200) and their corresponding F–C, DPPH, TEAC and FRAP values were employed to obtain four independent calibration models for predicting TPC and TAC for the extracts. Spectra from an extra 19 independent extracts were used as an external validation set for prediction. A correlation of r > 0.95 was obtained between FT-IR predicted and reference values (by F–C, DPPH, TEAC and FRAP assay) with standard errors of calibration (SEC) and standard errors of cross-validation (SECV) less than 2.85, 0.35 and 0.45 μmol Trolox/g FW of extracts for TEAC, FRAP and DPPH assay, respectively; and 0.36 mg gallic acid/g FW of extracts for the F–C assay. In addition, cluster analysis (principal component analysis (PCA)) and discriminant function analysis (DFA) could differentiate varieties of onions and shallot based upon infrared spectral features. Loading plots for the various chemometrics models indicated that hydroxyl and phenolic functional groups were most closely correlated with antioxidant capacity. The use of mid-infrared spectroscopy to predict the total antioxidant capacity of vegetables provides a rapid and precise alternative to traditional wet chemistry analysis.     

五倍子制备没食子酸丙酯的抗氧化活性研究

对天然植物五倍子浸提物没食子酸（GA）进行改性,得到没食子酸丙酯（PG）,并采用亚铁还原能力法（FRAP）、1,1-二苯基-2-三硝基苯肼（DPPH）自由基法、2-联氨-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）自由基法对其抗氧化活性进行评价。结果显示,FRAP值由大到小排序为：PG（FRAP值0.506）＞TBHQ（FRAP值0.412）＞BHA（FRAP值0.409）＞BHT（FRAP值0.067）;DPPH自由基清除能力由强到弱的顺序为：PG（IC50值4.2 μmol/L）＞BHT（IC50值53 μmol/L）＞TBHQ（IC50值87 μmol/L）＞BHA（IC50值816 μmol/L）;ABTS自由基清除能力由强到弱的顺序为：PG（IC50值 4.2 μmol/L）＞BHA（IC50值44 μmol/L）＞BHAT（IC50值45 μmol/L）＞TBHQ（IC50为50 μmol/L）。结果表明,PG的抗氧化活性均强于其他三种抗氧化剂,可作为新兴食品抗氧化剂应用。     

不同干燥方式对苹果蟠桃纸的感官品质和理化特性的影响

为了研究不同干燥方式对苹果蟠桃纸的感官品质和理化特性的影响,本文采用五种干燥方式（烘箱热风干燥、烤箱干燥、微波炉干燥、烤箱-烘箱联合干燥、烤箱-微波炉联合干燥）制备苹果蟠桃纸,考察不同干燥方式制备的苹果蟠桃纸在感官评定、质构、色泽、褐变度、总酚和维生素C含量、抗氧化活性等方面的差异。结果表明,烘箱热风干燥的产品的形态、口感、色泽、风味更能吸引感官评定人员,感官评定分数为最高（86.7）,总酚类含量最高（5.66 mg GAE/g dw）、抗氧化活性较强（DPPH自由基清除率66.00%,FRAP法测定的总还原能力0.32 mmol Trolox/g dw）,但维生素C含量较低（4.56 mg/100 g）、褐变程度较高。微波炉干燥的苹果蟠桃纸维生素C含量最高（9.78 mg/100 g）,但感官评定分数最低为66.7,总酚含量（4.11 mg GAE/g dw）和抗氧化活性最低（DPPH自由基清除率58.00%,FRAP法测定的总还原能力 0.18 mmol Trolox/g dw）。烤箱-烘箱联合干燥和烤箱-微波炉联合干燥的产品则没有突出优势。综上,建议在苹果蟠桃纸生产中不采用微波炉干燥,采用烘箱热风干燥。