Gannan Navel Orange Research Articles

Construction of a blockchain based cold chain logistics information platform for Gannan navel oranges to enhance transparency and efficiency

As a high-value agricultural product, the cold chain logistics management of Gannan navel oranges has global significance. Especially in Africa and Europe, food safety and supply chain quality are critical issues. However, the existing Gannan navel orange logistics information management system relies on traditional databases and information systems, with insufficient data sharing and transparency, affecting the overall coordination of the supply chain and customer satisfaction. In addition, the traditional system is vulnerable to hacker attacks and malicious tampering of data by insiders, resulting in serious economic losses and reputation damage. So the blockchain platform constructed in this study improves the transparency and traceability of logistics data through the SMART-PBFT algorithm of the alliance chain, which optimizes the logistics management process, improves the quality of logistics services, and reduces operating costs. It improves the logistics efficiency and data transparency of local agricultural products, and also provides a demonstrative case for the cold chain management of other high-value agricultural products around the world, with broad application potential and reference value.

Detection of Gannan Navel Orange Ripeness in Natural Environment Based on YOLOv5-NMM

In order to achieve fast and accurate detection of Gannan navel orange fruits with different ripeness levels in a natural environment under all-weather scenarios and then to realise automated harvesting of Gannan navel oranges, this paper proposes a YOLOv5-NMM (YOLOv5 with Navel orange Measure Model) object detection model based on the improvement in the original YOLOv5 model. Based on the changes in the phenotypic characteristics of navel oranges and the Chinese national standard GB/T 21488-2008, the maturity of Gannan navel oranges is tested. And it addresses and improves the problems of occlusion, dense distribution, small target size, rainy days, and light changes in the detection of navel orange fruits. Firstly, a new detection head of 160 × 160 feature maps is constructed in the detection layer to improve the multi-scale target detection layer of YOLOv5 and to increase the detection accuracy of the different maturity levels of Gannan navel oranges of small sizes. Secondly, a convolutional block attention module is incorporated in its backbone layer to capture the correlations between features in different dimensions to improve the perceptual ability of the model. Then, the weighted bidirectional feature pyramid network structure is integrated into the Neck layer to improve the fusion efficiency of the network on the feature maps and reduce the amount of computation. Lastly, in order to reduce the loss of the target of the Gannan Navel Orange due to occlusion and overlapping, the detection frame is used to remove redundancy using the Soft-NMS algorithm to remove redundant candidate frames. The results show that the accuracy rate, recall rate, and average accuracy of the improved YOLOv5-NMM model are 93.2%, 89.6%, and 94.2%, respectively, and the number of parameters is only 7.2 M. Compared with the mainstream network models, such as Faster R-CNN, YOLOv3, the original model of YOLOv5, and YOLOv7-tiny, it is superior in terms of the accuracy rate, recall rate, and average accuracy mean, and also performs well in terms of the detection rate and memory occupation. This study shows that the YOLOv5-NMM model can effectively identify and detect the ripeness of Gannan navel oranges in natural environments, which provides an effective exploration of the automated harvesting of Gannan navel orange fruits.

Untargeted metabolomics analysis of Gannan navel orange at different storage periods under room temperature using HS-SPME-GC-MS and UPLC-Q-TOF/MS

Navel orange remains metabolized continuously during postharvest storage, but few studies have monitored the changes of these metabolites. Therefore, HS-SPME-GC–MS and UPLC-Q-TOF/MS were used to comprehensively investigate the dynamic changes of the components of Gannan navel orange during storage at room temperature. A total of 62 volatile components and 68 non-volatile components were identified. Principal Component Analysis and Partial Least Squares Discriminant Analysis showed that navel orange under different storage periods were clearly distinguished. Combined with VIP > 1 and p < 0.05, 19 volatile and 27 non-volatile differential metabolites were obtained. KEGG enrichment analysis revealed that flavonoid biosynthesis (map00941) was the primary metabolic pathway. The middle storage period had a higher antioxidant enzyme activity, but the malondialdehyde content was the opposite. These results reveal the changes of postharvest components of Gannan navel orange, providing a theoretical basis for the storage and product development of navel orange.

Analysis of aroma components changes in Gannan navel orange at different growth stages by HS-SPME-GC–MS, OAV, and multivariate analysis

The ripe Gannan navel oranges have an appealing aroma, but few studies have reported the changes of these aromatic substances during the growth of navel oranges. In this study, changes of aroma components in Gannan navel orange from 119 to 245 days after flowering were systematically studied using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC–MS) coupled with multivariate analysis, including principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). A total of 43 and 54 aroma components were identified in pulp and peel of navel orange, respectively. The odor active value (OAV) results indicated that 14 substances were the key aroma components during the growth of navel orange. Among them, the contribution of linalool, β-myrcene and limonene were the highest. The multivariate statistical analysis further confirmed that 14 and 18 compounds could be used as key markers to distinguish the pulp and peel at different growth stages, respectively. Results from this study contributed to a better understanding of the dynamic variation and retention of aroma compounds during navel orange growth, and have great potential for industrial application.

First report of brown spot of Gannan navel orange caused by Cladosporium tenuissimum in Jiangxi Province, China

First report of brown spot of Gannan navel orange caused by Cladosporium tenuissimum in Jiangxi Province, China

Comparative study on chemical components of Gannan navel orange in different maturity stages based on UPLC-QTOF-MS metabolomics

Metabolites changes during fruit growth are currently being studied intensively. In this experiment, Ultra-high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry was used to identify metabolites during the growing phase of navel oranges. A total of 63 metabolites were identified, and monitored changes in amino acid content. Principal component analysis and Partial least-squares-discriminate analysis were used to construct a cluster analysis model among navel orange metabolites. Among the 19 differential metabolites, flavonoids were the main metabolic markers during the growth of navel oranges. Correlation cluster analysis was used to fit the correlation between the characteristic components, and it was found that many flavonoids were highly correlated. Finally, combined with Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the key metabolic pathway was identified as flavonoid synthesis. The α-glucosidase inhibition experiment showed that with the growth of navel orange, the inhibition rate of the metabolites to α-glucosidase activity decreased continuously. This study provides a necessary basis for exploring the metabolic mechanism of navel orange growth.

First Report of Postharvest Fruit Rot on Gannan Navel Orange Caused by Diaporthe unshiuensis in Jiangxi Province, China.

The Gannan navel orange (Citrus sinensis Osbeck cv. Newhall) is one of the most widely planted citrus fruit cultivars in Ganzhou City, Jiangxi Province, China. A Gannan navel orange was harvested from an orchard in Yudu County, Ganzhou City, Jiangxi Province, China, in October 2022 (25.95N, 115.41E). Approximately 5% of the fruit rotted after being stored at room temperature for about two weeks.Infected fruits appear brown and rotted with slightly indented edges. Initially symptoms of infected fruits was small circular, light brown, which the rot expands, slightly water-stained halo circle with slightly indented edges. The surface of 10 infected fruits was sterilized with 75% ethanol, and the lesion edge was cut into 5-mm-diameter pieces, and the pieces were then placed on potato dextrose agar (PDA) and incubated at 25°C for five days. A total of eight morphologically similar isolates were obtained. PDA results showed dense white and fluffy aerial mycelia in the center of colonies with sparser edges. Two types of conidia were produced; the alpha conidia were hyaline, ellipsoidal or clavate, and aseptate, with 2 oil drops, 4.8 to 7.5 × 2.1 to 2.7 μm (n=30). The beta conidia were hyaline, aseptate, filiform, smooth, straight to sinuous, 16.9 to 27.5 × 1.3 to 1.6 μm (n=30). These isolates exhibit morphological characteristics similar to those of the Diaporthe genus. Genomic DNA of two representative isolates (JFRL-03-1130 and JFRL-03-1131) was extracted for further confirmation. The internal transcribed spacer (ITS) region, beta-tubulin (TUB), calmodulin (CAL), partial translation elongation factor 1-alpha (TEF1-α), and histone H3 (HIS3) genes were amplified and sequenced using primers ITS1/ITS4, Bt2a/Bt2b, CAL228F/CAL737R, EF1-728F/EF1-986R, and CYLH3F/H3-1b, respectively (Udayanga et al. 2015). These nucleotide sequences were deposited into the GenBank database with accession numbers OQ691637-OQ691638 (ITS), OQ701022-OQ701023 (TUB), OQ701016-OQ701017 (CAL), OQ701018-OQ701019 (TEF1-α) and OQ701020-OQ701021 (HIS3). The maximum likelihood analyses were performed for the combined ITS, TEF1-a, TUB, HIS3, and CAL data set using Phylosuite V1.2.2 (Zhang et al. 2020). The phylogenetic tree showed that the two isolates clustered with D. unshiuensis in a clade with 100% bootstrap support. Therefore, the fungus was identified as D. unshiuensis based on morphological and molecular characteristics. To evaluate pathogenicity, a sterile scalpel was used to wound 10 surface-sterilized fruits, and a 5-mm-diameter mycelial plug of the isolate JFRL 03-1130, cultured on PDA at 25℃ for 7-days, was put on the wound. Another set of 10 fruits was similarly inoculated with sterile agar plugs as controls. The fruits were cultured at 25°C and 85% relative humidity, and the test was repeated twice. These fruits inoculated with D. unshiuensis showed similar rot symptoms after 10 days, while the control group remained symptomless. In order to prove Koch's postulates, the pathogen was re-isolated from the inoculated fruits and confirmed as D. unshiuensis by molecular techniques, but never from the control fruits. Diaporthe unshiuensis has been reported as an endophyte associated with citrus and a pathogen that causes melanose disease in citrus (Chaisiri et al. 2020; Huang et al. 2015). However, to the best of our knowledge, this is the first reported case of D. unshiuensis causing postharvest fruit rot on Citrus sinensis. In the past, D. sojae has also been reported causing postharvest fruit brown rot disease on Citrus sinensis in China (Xiao, et al. 2023); Therefore, managers should pay more attention to postharvest fruit rot disease caused by Diaporthe species and implement storage strategies to control and reduce losses.

Isolation, identification, and antibacterial evaluation of endophytic fungi from Gannan navel orange.

Gannan navel orange is a famous brand in China but the isolation of its endophytic fungi was rarely reported. In this study, a total of 54 strains of endophytic fungi were successfully isolated from the pulp, peel, twig, and leaf of Gannan navel orange; they were successfully identified to belong to 17 species of 12 genera. All these strains were fermented using potato-dextrose agar (PDA) medium, and their secondary metabolites were then extracted with ethyl acetate (EtOAc). The antibacterial assays of Escherichia coli (E. coli), methicillin-resistant Staphylococcus aureus (MRSA), and Xanthomonas citri subsp. citri (Xcc) were also performed for the EtOAc extracts of these strains. As a result, the extracts of both Geotrichum sp. (gc-1-127-30) and Diaporthe biconispora (gc-1-128-79) demonstrated significant antibacterial activities against Xcc, and the MIC value for the extract of Colletotrichum gloeosporioides against MRSA was low to 62.5 μg/mL. Moreover, the chemical components of the extracts of Colletotrichum sp., Diaporthe biconispora, and Annulohypoxylon atroroseum were primarily investigated, and they successfully led to the isolation of 24 compounds involving a new botryane sesquiterpene. Among the isolated products, compound 2 showed significant inhibitory activities toward SA, MRSA, E. coli, and Xcc with MIC values of 12.5, 3.1, 125, and 12.5 μg/mL, respectively. This study revealed that the endophytic fungi of Gannan navel orange showed high potency to produce secondary metabolites with significant antibacterial effects.

Recuperação do teor de clorofila de folhas em laranja do umbigo Gannan com base na fusão de índices de vegetação hiperespectral usando algoritmos de inteligência artificial

ABSTRACT: Estimating leaf chlorophyll contents through leaf reflectance spectra is efficient and nondestructive. The literature base regarding optical indices (particularly chlorophyll indices) is wide ranging and extensive. However, it is without much consensus regarding robust indices for Gannan navel orange. To address this problem, this study investigated the performance of 19 published indices using RDS (raw data spectrum), FDS (first derivative data spectrum) and SDS (second derivative data spectrum) for the estimation of chlorophyll content in navel orange leaves. The single spectral index and combination of multiple spectral indices were compared for their accuracy in predicting chlorophyll a content (Chla), chlorophyll b content (Chlb) and total chlorophyll content (Chltot) content in navel orange leaves by using partial least square regression (PLSR), adaboost regression (AR), random forest regression (RFR), decision tree regression (DTR) and support vector machine regression (SVMR) models. Through the comparison of the above data in three datasets, the optimal modeling data set is RDS data, followed by FDS data, and the worst is SDS data. In modeling with multiple spectral indices, good results were obtained for Chla (NDVI750, NDVI800), Chlb (Datt, DD, Gitelson 2) and Chltot (Datt, DD, Gitelson2) by corresponding index combinations. Overall, we can find that the AR is also the best regression method judging by prediction performance from the results of single spectral index models and multiple spectral indices models. In comparison, result of multiple spectral indices models is better than single spectral index models in predicting Chla and Chltot content using FDS data and SDS data, respectively.

The Effects of Storage Temperature, Light Illumination, and Low-Temperature Plasma on Fruit Rot and Change in Quality of Postharvest Gannan Navel Oranges.

Gannan navel orange (Citrus sinensis Osbeck cv. Newhall) is an economically important fruit, but postharvest loss occurs easily during storage. In this study, the effects of different temperatures, light illuminations, and low-temperature plasma treatments on the water loss and quality of the Gannan navel orange were investigated. The fruit began to rot after 90 d of storage at 5 °C and 20-45 d at 26 °C. Navel oranges stored at 26 °C had 7.2-fold and 3.1-fold higher rates of water loss at the early and late storage stages, respectively, as compared with those stored at 5 °C. Storage at 5 °C decreased the contents of total soluble solids at the early storage stage and the contents of titratable acids at the late storage stage, whereas storage at 26 °C decreased the contents of total soluble solids at the late storage stage and the contents of titratable acids at the early storage stage, respectively. Application of low-temperature plasma produced by air ionization for 6 min, or continuous blue or red light illumination significantly inhibited water loss within 7 and 21 d of storage at 22 °C, respectively, but exhibited no significant effect on fruit quality. Furthermore, the low-temperature plasma treatment protected against fruit rot. Thus, treatment with low-temperature plasma followed by storage at a low temperature under continuous red or blue light illumination was of potential value as a green technology for preserving Gannan navel orange during storage.

Effect of harvest time on the chemical composition and antioxidant capacity of Gannan navel orange (Citrus sinensis L. Osbeck ‘Newhall’) juice

The present study investigates the chemical composition and antioxidant capacity of juice from the Gannan navel orange, which is harvested at one- to two-week intervals during the ripening period. The total soluble solid (TSS), total polyphenol content (TPC), total flavonoid content (TFC), sucrose and hesperidin contents gradually increase with the ripening of the fruit, followed by slight declines at the late maturity stage. Contrary to these observations, the contents of titratable acid (TA), vitamin C (Vc), and limonin trend downward throughout the ripening period. However, the contents of fructose, glucose, and narirutin fluctuate throughout the harvest time. Three in vitro antioxidant assays consistently indicate that the harvest time exerts no significant influence (P>0.01) on the antioxidant capacity. Furthermore, principal component analysis (PCA) and Pearson's correlation test are performed to provide an overview of the complete dataset. This study provides valuable information for evaluating the fruit quality and determining when to harvest the fruit in order to meet the preferences of consumers. Meanwhile, our observations suggest that the fruits subjected to juice processing should be harvested at the late maturity stage to alleviate the “delayed bitterness” problem without compromising the antioxidant capacity and the flavonoid content in the juice.

The Regulatory Effects of Citrus Peel Powder on Liver Metabolites and Gut Flora in Mice with Non-Alcoholic Fatty Liver Disease (NAFLD).

Gannan navel orange and Jinggang pomelo, belonging to the genus Citrus, are good sources of phenolic compounds, which are mainly concentrated in the peel. These phenolic compounds are considered promising in the prevention and treatment of non-alcoholic fatty liver disease (NAFLD). In order to maximize nutrients retention and bioactivity in the peel, pomelo peel and orange peel were processed using freeze-drying technology and mixed in the ratio (pomelo peel powder 50% and orange peel powder 50%) to make citrus peel powder (CPP). The purpose of this study was to explore new strategies and mechanisms associated with the consumption of CPP to alleviate nonalcoholic fatty liver injury, lipid metabolism disorders, and gut microbiota dysbiosis in obese mice induced by high-fat diet (HFD). The results showed that after 12 weeks of CPP administration, CPP supplementation had a strong inhibitory effect on HFD-induced weight gain, hepatic fat accumulation, dyslipidemia, and the release of pro-inflammatory cytokines. In particular, CPP modulates the composition of the intestinal flora, such as increasing the relative abundance of phylum Firmicutes, genus Faecalibaculum, genus Lactobacillus, genus Dubosiella, and genus Lachnospiraceae_NK4A136_ group and decreasing the relative abundance of phylum Bacteroidota, genus Helicobacter, and genus Bacteroides. These results suggest that CPP has a preventive effect on NAFLD, which can be related to the regulation of intestinal flora.

Effects of storage time and temperature on the chemical composition and organoleptic quality of Gannan navel orange (Citrus sinensis Osbeck cv. Newhall)

Effects of storage time and temperature on the chemical composition and organoleptic quality of Gannan navel orange (Citrus sinensis Osbeck cv. Newhall)

Ultrasonic-assisted extraction of carotenoids from navel orange in southern Jiangxi

In this study, single factor experiment and orthogonal experiment were used to study the extraction effect of carotenoids from navel orange in southern Jiangxi Province assisted by ultrasonic technology. The experimental results showed that when hexane: ethanol=1:1 as the extraction agent, liquid to solid ratio of 1:30, extraction time of 8 min, ultrasonic power of 250 W, extraction temperature of 25°C, extraction times of 4 times, the best extraction effect of carotenoids from Gannan navel orange was obtained.

Soil applied Ca, Mg and B altered phyllosphere and rhizosphere bacterial microbiome and reduced Huanglongbing incidence in Gannan Navel Orange

Huanglongbing (HLB) caused by ‘Ca. Liberibacter. Asiaticus (Clas)’ is one of the destructive diseases for citrus, threatening the development of citrus industry. Adopting a proper fertilization method instead of using pesticides seems particularly important, which would contribute to a sustainable development of orchard. In this study, the impact of soil application of nutrients combined with foliar spray of macro- and micro-nutrients on the incidence of HLB and the phyllosphere and rhizosphere bacterial microbiome was investigated in Gannan Navel Orange orchard from 2015 to 2018. Compared with the control (T1), the yield of Gannan Navel Orange in all other treatments applied with macro- and micro-nutrients increased significantly in 2018 (by 20.5%–45.8%), but not in the first two years (2016–17). Among treatments, Ca + Mg + B application in soil (T2) showed the highest yield and lowest HLB incidence. According to the PCR results, CLas was negative in T2 but positive in the control, which directly proved HLB incidence was reduced with Ca + Mg + B application in soil. Moreover, 16S rRNA sequencing was used to characterize rhizosphere and phyllosphere microbial communities. Results showed that microbial biodiversity was increased and microbial community structure was altered in T2 treatment, of which the beneficial bacteria were enriched in phyllosphere and rhizosphere. The results of PICRUSt showed that in T2 treatment, rhizosphere microbe contained more membrane transport (ABC transporters) genes, while, carbohydrate metabolism genes were enriched in the control rhizosphere due to HLB obstruct the photosynthetic metabolite transport. In summary, results indicated that macro- and micro-nutrients application improved the yield of Gannan Navel Orange and soil application of Ca + Mg + B reduced HLB incidence by altering microbial community structure and increasing microbial biodiversity. This study developed an environment-friendly way to reduce HLB incidence and improve the yield of citrus.

Research on Comprehensive Processing Technology of Gannan Navel Orange

Gannan navel orange has been well known since the 1970s. With the development of the country and society, navel orange has formed an overall system, including planting, production, storage, preservation, processing and other work processes. The technology of food processing with raw materials is becoming more and more extensive.

Estimating Total Leaf Chlorophyll Content of Gannan Navel Orange Leaves Using Hyperspectral Data Based on Partial Least Squares Regression

The goal of this study was to model the total leaf chlorophyll content (LCCtot) of Gannan navel orange leaves using a field imaging spectroscopy system in the visible and near-infrared domain. The spectral range from 400 to 1000 nm with 176 wavebands (a wavelength interval of 3.41 nm) or 360 wavebands (a wavelength interval of 1.67 nm), labeled as “Datasets_1.67” and “Datasets_3.41”, respectively, were used. Although different spectral data types were used, better prediction results for LCCtot were based on Datasets_1.67 for LCCtot prediction. Several prediction models of LCCtot were built based on partial least squares regression (PLSR), artificial neural networks (ANN), ordinary least squares regression (OLSR), and stepwise linear regression (SLR) using full spectral and effective wavelength (EW) data (raw spectral (RS), first derivative spectral (FDS) and second derivative spectral (SDS) data). The determination coefficient (R 2 ), the root mean square error (RMSE) and the residual predictive deviation (RPD) were used to evaluate the reliability and accuracy of the predicted LCCtot values. As a result, 14 (7 obtained from Datasets_1.67, 7 obtained from Datasets_3.41), 39 (21 obtained from Datasets_1.67, 18 obtained from Datasets_3.41) and 50 (27 obtained from Datasets_1.67, 23 obtained from Datasets_3.41) wavebands were selected from the RS data, FDS data and SDS data, respectively, as the EWs for LCCtot prediction of navel orange leaves. After that, PLSR and ANN predictive models were established using full spectra, and OLSR and SLR predictive models were built using the selected EWs. The experimental results demonstrated that these various regression methods were useful for estimating LCCtot in the order of PLSR models established using full spectra from RS data (F-RS-PLSR) > PLSR models established using full spectra from SDS data (F-SDS-PLSR) > PLSR models established using full spectra from FDS data (F-FDS-PLSR) > SLR models established using EWs by RS data (EWs-RS-SLR). However, models built with ANN and OLSR, where the RPD values were less than 3, cause the models to be inaccurate. Finally, in comparison, the F-RS-PLSR model exhibited the best performance of LCCtot estimation; with the number of principal components (Pcs) = 5, this model provided high values of the R 2 of calibration (C-R 2 ) = 0.92 and the R 2 of validation (V-R 2 ) = 0.96, small values of the RMSE of calibration (C-RMSE)=0.05 mg/g and the RMSE of validation (V-RMSE) = 0.19 mg/g, and sufficient the RPD of calibration (C-RPD)=17.00 and the RPD of validation (V-RPD)=3.63 values. Overall, the best modeling method was PLSR. Hence, the PLSR applicability for assessing chlorophyll content in navel orange leaves was demonstrated.

A nonlinear empirical analysis on influence factor of circulation efficiency

A series of phenomena including lower circulation efficiency of Chinese fresh agricultural products, postharvest decay, damage and waste of agricultural products, regional and structural contradiction of supply and demand, drastic fluctuation in price and difficulty in buying and selling, etc. are serious, which has restricted the sound development of Chinese fresh agricultural product industry. To analyze and discuss main factors affecting circulation efficiency of Gannan navel orange, the methods, such as AHP (analytic hierarchy process) and Delphic method, etc., have been used for empirical analysis on Gannan navel orange, and it is found that fruit factors (including single structure and centralized mature period of navel orange, etc), infrastructure factors (including the lack standardization for construction of trading place, outdated warehousing facility and technology, insufficient input of infrastructure of cold chain, etc) and policy environment factors (including food safety, absence of relevant laws and regulations of market supervision, etc) are the existing main factors restricting high-efficient circulation of Gannan navel orange. Based on the conclusion of empirical research and beginning with main circulation links of production, storage and transportation as well as marketing, etc and supporting measures of brand building, product safety and policy service system, etc, the countermeasures and suggestions are proposed to improve circulation efficiency of Gannan navel orange.

Chemical composition and antimicrobial activity of Gannan navel orange (Citrus sinensis Osbeck cv. Newhall) peel essential oils.

The present investigation reported the chemical composition of cold pressed Gannan navel orange peel essential oil (EO) and its molecular distillation fraction (light phase EO), and examined their antimicrobial activity against spoiling and pathogenic microorganisms. Gas chromatography‐mass spectrometry analysis identified 27 and 20 different chemical constituents in cold pressed EO and light phase EO, respectively. Limonene was the major constituent, accounting for 85.32% of cold pressed EO and 60.44% of light phase EO. Both EOs and some of their constituents showed good antimicrobial activity. Compared to cold pressed EO, light phase EO exhibited the better antimicrobial activity under weak acidic and neutral conditions. The light phase EO presented a higher antimicrobial activity after thermo‐treatment at 60–100°C for 20 min than cold pressed EO. These results demonstrated that light phase EO had a potential to be used as a novel antimicrobial agent for food preservation and food processing.

Antioxidant and Anticancer Activities of Essential Oil from Gannan Navel Orange Peel.

China is one of the leading producers of citrus in the world. Gannan in Jiangxi Province is the top navel orange producing area in China. In the present study, an essential oil was prepared by cold pressing of Gannan navel orange peel followed by molecular distillation. Its chemical composition was analyzed by GC-MS. Twenty four constituents were identified, representing 97.9% of the total oil. The predominant constituent was limonene (74.6%). The anticancer activities of this orange essential oil, as well as some of its major constituents, were investigated by MTT assay. This essential oil showed a positive effect on the inhibition of the proliferation of a human lung cancer cell line A549 and prostate cancer cell line 22RV-1. Some of the oil constituents displayed high anticancer potential and deserve further study.