The toxicity, carcinogenicity and persistence of polycyclic aromatic hydrocarbons (PAHs) pose a great threat to the ecological system and human health. The contamination levels, translocation and ...source analysis of 16 PAHs in bamboo shoot and its planted soil were investigated. The average concentrations of total PAHs were 18.80 ± 1.90 µg/kg and 123.98 ± 113.36 µg/kg in bamboo shoots and soils, respectively. The most abundant PAH was Phenanthrene (PHE), with the detected average concentrations of 5.85 µg/kg in bamboo shoots and 19.28 µg/kg in soils. The highest detected types of PAHs were 3 rings and 4 rings, with the proportions of 80.69% (bamboo shoots) and 35.23% (soils). The transfer factors of PAHs were ranged from 0.011 to 0.895, in which PAHs with 3 rings showed the strongest transfer ability. The combustion of biomass and petroleum might be the main source of PAHs in the planted soils of bamboo shoots.
Abstract Drying techniques are being used more and more to extend the shelf life of industrial products. Drying could influnce the content of phenolics in food and their antioxidant activity. This ...study estimated the effects of different drying methods (freeze drying (FD), gradient hot air drying (GHD), and constant hot air drying (CHD)) on phenolic profiles and antioxidant activities in walnut kernels. With a maximum content of 3.61 mg g −1 , GHD was found to be the most effective in preserving total phenols, while CHD and FD had maximum contents of 2.66 mg g −1 and 1.96 mg g −1 , respectively. The concentration of most monomeric phenols detected in the kernels increased with temperature, particularly in the free and bound forms. Gallic acid (free form) levels in GHD2 (194.54 µg g −1 ) were 55.77 and 60.08 times higher, respectively, than in FD and CHD. GHD dried walnuts had higher antioxidant activity than FD and CHD dried walnuts. Furthermore, bioinformatics analysis revealed three key metabolic pathways associated with the mechanisms underlying drying changes. The GHD technique, according to these findings, is a better choice for drying walnut in order to preserve its phenolics and antioxidant activity. Graphical Abstract
The extraction and quantitative determination of phenolic compounds (including phenolic acids, flavones, flavanols, alkaloid, tannins, procyanidins, and naphthoquinone) from the walnut kernel and its ...pellicle were performed by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Effective parameters on the tandem MS conditions, chromatographic conditions, and extraction solvents were evaluated and optimized. Under optimum condition, limits of detection and linearity were 0.000565–33.3 μg/g and 10–1000 ng/mL with
r
-values > 0.9952, respectively. The relative standard deviation from extraction recovery was from 74.27 ± 2.81% to 109.52 ± 4.33%, with precision values of < 15%. The proposed method was applied for simultaneous extraction and determination of phenolic compounds not only in the walnut kernel and its pellicle, but also in other tree nuts.
Walnut is one of the most popular nuts worldwide and contains various mineral nutrients. Little is known, however, about the relationship between toxic heavy metals in walnuts and growth soil. In ...this study, we investigated the distribution, relationship, and risk assessment of five toxic heavy metals—lead (Pb), arsenic (As), chromium (Cr), cadmium (Cd), and mercury (Hg)—in walnuts and growth soil in the main production areas of China. The results showed that the main heavy metal pollution in walnut and soil was Pb and Cd. Regionally, positive relationships existed between heavy metals and the pH and organic matter of soil. In addition, we observed a notable uptake effect between walnut and growth soil. In this study, we found a significant correlation (
r
= 0.786,
P
< 0.05) between the bioconcentration factors and the longitude of the sampling areas. The risks (total hazard quotients) of five heavy metals toward children and adults by dietary walnut consumption were 46.8 and 56.2%, respectively. The ability to identify toxic heavy metal pollution in walnuts and growth soil could be helpful to screen suitable planting sites to prevent and control heavy metal pollution and improve the quality and safety of walnut.
A matrix solid-phase dispersion and direct competitive enzyme-linked immunosorbent assay (MSPD-ELISA) was developed for five organophosphorus pesticides (OPs) in camellia oil. Seven haptens with ...different substituents in the aromatic ring were used to prepare different competitors; the ELISA showed highest sensitivity and specificity to OPs when the competitor had moderate heterology to the immunizing hapten. Several assay conditions were optimized to increase the ELISA sensitivity. The optimized ELISA for five OPs had 50% inhibitory concentrations of 6.3 ng/ml (parathion), 18.9 ng/ml (methyl parathion), 120.7 ng/ml (fenitrothion), 110.4 ng/ml (fenthion), and 20.7 ng/ml (phoxim). The average recoveries of five OPs in camellia oil ranged from 75.7 to 105.3%, with the interassay coefficient of variations ranging from 6.0 to 13.4%. Compared with the results previously reported, the ELISA that was developed in the present study showed a much higher sensitivity. Additionally, MSPD was used in the sample preparation to minimize the matrix effect. Recoveries from the method developed here were in agreement with those obtained by gas chromatography, which indicated that the detection performance of the MSPD-ELISA could meet the regulatory requirements of different governments and international organizations.
Little is known about the phytochemical composition of iron walnuts. Differences in the geographical origin of iron walnuts associated with economic benefits should also be examined. In this study, ...the phytochemical composition (fatty acids, Vitamin E, total polyphenols and flavonoids, amino acids, and minerals) of iron walnuts in China was investigated. The results showed that there were significant differences (
p
< 0.05) in the phytochemical composition of iron walnut oils and flours from different regions. Positive (r > 0.5,
p
< 0.05) and negative (r < − 0.5,
p
< 0.05) correlations were found between amino acids/minerals and amino acids/oleic acid, with the highest correlation coefficient (r = 0.742,
p
< 0.05) between Cu and tyrosine. In addition, based on the 12 phytochemical fingerprints selected by random forest, a geographical-origin identification model for iron walnuts was established, with a corresponding correct classification rate of 96.6%. The top three phytochemical fingerprints for the geographical-origin identification of iron walnut were microelements, macroelements, and antioxidant composition, with contribution rates of 61.7%, 18.1%, and 9.9%, respectively.
There is very little information on the impacts of pre/post-harvest stresses on oilseeds. Individual and combined insect (pre-harvest) and heat stress (post-harvest) impacts on the metabolic profile ...of camellia oilseeds (COs) were investigated using a combination of widely-targeted metabolomics and network pharmacology. A total of 1875 metabolites were identified. In response to individual and combined stresses, 169 (insect),149 (heat), and 21 (insect + heat) metabolites were screened as differential metabolic markers (DEMs), Terpenoids, phenolic acids, and flavonoids are the most impacted metabolite species, accounting for almost 49% of total DEMs. Then network pharmacological analysis identifies 98 key active ingredients (AIs) in CO. A single stress may induce CO to impede cardiovascular system function, but the combined stress induced AI-promoting effects of CO in the urinary system. The individual and combined perturbed biological mechanisms were related to the flavonoid biosynthesis and the biosynthesis of various plant secondary metabolites pathway, respectively.
•Individual and combined impacts induced by insect/heat stress was investigated•49% of total differential metabolic markers are terpenoids and phenolics•Individual stress perturbed the pathway of flavonoid biosynthesis•Combined stresses perturbed the biosynthesis of various plant secondary metabolites
Cultivar is one of the key factors to that influences the nutritional and commercial values of walnuts. However, differences in the comprehensive chemical components among walnut cultivars and their ...internal formation mechanism are rarely reported. In this study, 49 chemical components of 10 main walnut cultivars from Shanxi Province, China were investigated. Polyphenols, flavonoids and vitamin E were especially rich with the contents of 32.20 mg/g, 16.25 mg/g and 42.37 mg/g, respectively. Highly positive correlations existed among amino acids (r > 0.77,
p
< 0.01), polyphenols-flavonoids (r = 0.85,
p
< 0.01) and α-Vitamin E - γ-Vitamin E (r = 0.93,
p
< 0.01). Some microelements (Tl, Ba and Ni) were negatively correlated with most of the essential amino acids (expect for Cys and Lys), α-Vitamin E and γ-Vitamin E. Based on further analysis of the relationships between chemical component groups, there were 13 canonical variate pairs between microelements and other chemical composition groups was up to 13 pairs (r > 0.8,
p
< 0.01). Then correspondence analysis indicated 17 chemical compositions were typical phytochemical component of these walnut cultivars. Microelements were the major factor that influenced on the comprehensive qualities of walnuts. Finally, walnut cultivars were classified into various industrial developments based on their chemical components. This research demonstrated that differences and relationships of chemical components in walnuts could be efficiently determined and further applied to the food industry.
The diversity of cultivars and variation in phytochemical components pose a great threat to the security of foods that contain walnut. The nutrient values of walnut are stipulated according to ...phytochemical components, which are driven by internal and external factors associated with fruit growth. The objective of this work was to investigate the effects of cultivar and climate zone on the phytochemical components of walnuts. First, differences and relationships of phytochemical components in eleven walnut cultivars harvested from northeastern China were analyzed. Almost all individual phytochemical components among cultivars showed significant differences (p < .05). The results were submitted to correspondence analysis followed by matrix transformation and factor analysis. Fatty acids, amino acids, and minerals (Ca, Na, Fe, Cu, P, and Zn) for the identification and discrimination of eleven walnut cultivars were authenticated. Furthermore, based on essential microelements, essential amino acids, unsaturated fatty acids, and antioxidants, the walnut cultivars realized the precision position in food application. Finally, we confirmed the effects of climate zones on the phytochemical components of walnuts, with variations up to 142%. The climatic factors precipitation and temperature influenced the formation and accumulation of monounsaturated fatty acids, tocopherols, and most minerals. The findings will open promising perspectives for oriented cultivation of walnuts and future application in the food industry.
The differences and relationships of 49 phytochemical components and their influence factor (cultivar and climate zone) were comprehensively analyzed. Based on correspondence analysis and specific nutritive characters, the walnut cultivars realized the precision position in the food industry. Precipitation and temperature were the important climatic factors for the formation of MUFA, Ve, and most of the minerals.
Due to the widespread use and potential toxicity of organophosphorous pesticides (OPs), multiresidue monitoring of OPs in camellia oil has become increasingly important. A simple, rapid, and ...effective matrix solid‐phase dispersion extraction for the determination of 15 organophosphorous pesticides in camellia oil is described. Related important factors influencing the extraction efficiency, such as type of sorbent material, eluting solvent, and ratio of sample/sorbent were studied and optimized. The best results were obtained using 0.5 g of camellia oil, 1.5 g of white carbon black as dispersant sorbent, and 5 mL of acetonitrile: ethyl acetate (2:1, V/V) as eluting solvent. Method validation was performed in order to study sensitivity, linearity, precision, and accuracy. Average recoveries ranged between 76.7% and 102.9% with relative standard deviation values from 2.9% to 13.7% at 2 concentration levels (10 and 100 μg/kg). The method limit of detection at or below the regulatory maximum residue limits for the pesticides was achieved.
Practical Application: A simple, rapid, and effective method for multiresidue determination of organophosphorous pesticides in camellia oil was developed. The sample preparation could finish in 5 min.
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