Search

Pesticides are widely used in the process of kiwifruit growth to promote fruit expansion. This study was aimed to assess the effects of pesticides on the quality of kiwifruit by applying high and normal concentrations of forchlorfenuron (CPPU) and thidiazuron (TDZ) to "Xuxiang" (XX) green kiwifruit and "Jinyan" (JY) gold kiwifruit. Sixty kiwifruit trees were used to comprehensively evaluate the effects on the pulp and whole kiwifruit. In addition to the weight gain effect and basic physical-chemical properties (vitamin C, total protein, glucose and fructose, organic acids), the main nutritional qualities (in vitro and cellular antioxidant activity (CAA), and dietary minerals) were also evaluated. The vitamin C content of XX was not affected by pesticides, but the use of CPPU reduced vitamin C of JY pulp by 23% (p < 0.05). Pesticides did not reduce the antioxidant values of XX pulp in vitro but significantly reduced CAA values (32%-47%). In JY pulp, pesticides treatments had no significant effect on antioxidant values in vitro except that CPPU treatments significantly reduced the ferric reducing antioxidant power (FRAP) value by 21% (p < 0.05). Reasonable use of pesticides can effectively improve taste of kiwifruit, increasing kiwifruit weight and the content of certain nutrients. PRACTICAL APPLICATION: Based on observed changes in nutritional components, CPPU may be more suitable for XX while TDZ may be more suitable for JY. The significance of this study may affect kiwifruit farmers and ultimately help improve the sensory quality of kiwifruit.

Bioactive composite films were obtained by adding Lactobacillus paracasei into a hydroxypropyl cellulose (HPC)-konjac flour (KF) matrix through a casting method. The mechanical, optical, and barrier properties were tested to determine the influence of the addition of lactobacilli into complex films. For purpose of evaluating the surface morphology of the composite films, scanning electron microscopy and atomic force microscopy were carried out. Fourier transform infrared spectroscopy and X-ray diffraction analyses were conducted to evaluate intermolecular interactions and crystallinity, respectively. Moreover, the microbial viability of the lactobacilli and the antibacterial activities of the bioactive films against pathogenic organisms were measured. The results indicated that the mechanical properties, crystalline properties, oxygen permeability, and color characteristics were not notably altered; nevertheless, the gloss and water vapor barrier properties were relatively weakened by the incorporation of L. paracase. The HPC-KF-L. paracasei films were effective in inhibiting both gram-positive (Listeria monocytogenes, Staphylococcus aureus) and gram-negative (Escherichia coli, Salmonella typhimurium) pathogens, and the films can retain physical property and antibacterial activity within a storage period of 30 days. The composite films, acting as suitable carriers for L. paracasei and possessing noteworthy bacteriostatic activities, could be developed as bioactive packaging for preserving food.; Practical Application: For the sake of the high desires of consumers for food safety and quality, the development of innovative bioactive packaging has attracted wide attention. In this work, the prepared films containing lactic acid bacteria showed great physical property, antipathogenic activity, and fresh-keeping property preservation, and have great application potential in fresh food preservation.; © 2018 Institute of Food Technologists®.

Use of organic solvents to extract phenolic compounds from plants may result in environmental pollution and cause health problems in persons. Replacing organic extraction solvents by green extracting agents without affecting the extraction yield is one of the most pressing problems to be solved. The aim of this study is to evaluate the capacity of β-cyclodextrin (β-CD) to recover phenolic compounds from tea leaves. The extract obtained using the ethanol/water mixture presented the highest total phenolic content, followed by those obtained using β-CD solution and water. HPLC analysis of the extracts showed that the addition of β-CD to the extracting agent had a selective effect on the extraction of epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). The extraction yield of EGCG and ECG using 15 g/L β-CD were higher than that obtained using water and 50% ethanol. Molecular docking results indicated that the molecules of EGCG and ECG were more inclined to interact with β-CD than epigallocatechin, epicatechin, and gallocatechin. The impact of β-CD concentration, temperature, and time on EGCG and ECG extraction from tea leaves was investigated and the maximum amount of EGCG (118.7 mg/g) and ECG (54.6 mg/g) were achieved when extracted with 25 g/L aqueous β-CD solution at 60 °C for 60 min. The present study indicates that aqueous β-CD can be used as an alternative to organic solvents to recover EGCG and ECG from tea leaves.

This work was undertaken to evaluate the microbiological characteristics and antioxidant and physiological activities in kiwifruits (Actinida deliciosa var. Qinmei) with/without cinnamaldehyde (C1) and citral (C2) fumigation treatments (5 μL/L) during 0, 3, 6, 9, and 12 d of storage at 4 °C. Essential oils (EOs) treatment lowered the total viable counts, yeast, and mold to 1.54, 2.36, and 2.05 log CFU/g, respectively. Moreover, EOs improved the antioxidant activities of kiwifruit. They enhanced phenolics and flavonoids content in fruit tissue by 49.48% at day 3 and 56.93% at day 6, respectively. In addition, ascorbic acid in treated groups had the lower losing rate. Similarly, MDA (malondialdehyde), H2 O2 (hydrogen peroxide), and • O2- (superoxide anion) production were effectively decreased in the range of 27.27% to 54.38%. Physicochemical characteristics showed that kiwifruits from treated group maintained higher levels of flesh luminosity and firmness. EOs also decreased the levels of reducing sugar by 45.97% at day 3, and increased the content of soluble protein and hydrolyzed amino acid. Therefore, postharvest EOs treatment has positive effects on delaying senescence and enhancing antioxidant capacities in kiwifruit.

Bioactive composite films were obtained by adding Lactobacillus paracasei into a hydroxypropyl cellulose (HPC)-konjac flour (KF) matrix through a casting method. The mechanical, optical, and barrier properties were tested to determine the influence of the addition of lactobacilli into complex films. For purpose of evaluating the surface morphology of the composite films, scanning electron microscopy and atomic force microscopy were carried out. Fourier transform infrared spectroscopy and X-ray diffraction analyses were conducted to evaluate intermolecular interactions and crystallinity, respectively. Moreover, the microbial viability of the lactobacilli and the antibacterial activities of the bioactive films against pathogenic organisms were measured. The results indicated that the mechanical properties, crystalline properties, oxygen permeability, and color characteristics were not notably altered; nevertheless, the gloss and water vapor barrier properties were relatively weakened by the incorporation of L. paracase. The HPC-KF-L. paracasei films were effective in inhibiting both gram-positive (Listeria monocytogenes, Staphylococcus aureus) and gram-negative (Escherichia coli, Salmonella typhimurium) pathogens, and the films can retain physical property and antibacterial activity within a storage period of 30 days. The composite films, acting as suitable carriers for L. paracasei and possessing noteworthy bacteriostatic activities, could be developed as bioactive packaging for preserving food.For the sake of the high desires of consumers for food safety and quality, the development of innovative bioactive packaging has attracted wide attention. In this work, the prepared films containing lactic acid bacteria showed great physical property, antipathogenic activity, and fresh-keeping property preservation, and have great application potential in fresh food preservation.

Yeasts and yeast-like fungal isolates were recovered from apple orchards and apple juice processing plants located in the Shaanxi province of China. The strains were evaluated for osmotolerance by growing them in 50% (w/v) glucose. Of the strains tested, 66 were positive for osmotolerance and were subsequently identified by 26S or 5.8S-ITS ribosomal RNA (rRNA) gene sequencing. Physiological tests and RAPD-PCR analysis were performed to reveal the polymorphism of isolates belonging to the same species. Further, the spoilage potential of the 66 isolates was determining by evaluating their growth in 50% to 70% (w/v) glucose and measuring gas generation in 50% (w/v) glucose. Thirteen osmotolerant isolates representing 9 species were obtained from 10 apple orchards and 53 target isolates representing 19 species were recovered from 2 apple juice processing plants. In total, members of 14 genera and 23 species of osmotolerant isolates including yeast-like molds were recovered from all sources. The commonly recovered osmotolerant isolates belonged to Kluyveromyces marxianus, Hanseniaspora uvarum, Saccharomyces cerevisiae, Zygosaccharomyces rouxii, Candida tropicalis, and Pichia kudriavzevii. The polymorphism of isolates belonging to the same species was limited to 1 to 3 biotypes. The majority of species were capable of growing within a range of glucose concentration, similar to sugar concentrations found in apple juice products with a lag phase from 96 to 192 h. Overall, Z. rouxii was particularly the most tolerant to high glucose concentration with the shortest lag phase of 48 h in 70% (w/v) glucose and the fastest gas generation rate in 50% (w/v) glucose. Practical Application The findings of this study will supplement existing literature and increase our understanding of the osmotolerant yeasts present in apple-related environments and their tolerance to high glucose concentrations.

A reliable and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of aflatoxins (AFB1, AFB2, AFG1, and AFG2), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEA), fumonisin B1 (FB1), and T2-toxin in maize. The samples were first extracted using acetonitrile: water: acetic acid (79 : 20 : 1), and then further cleaned-up using OASIS HLB cartridge. Optimum conditions for the extraction and chromatographic separation were investigated. The mean recoveries of mycotoxins in spiked maize ranged from 68.3% to 94.3%. Limits of detection and quantification ranged from 0.01 to 0.64 μg/kg and from 0.03 to 2.12 μg/kg, respectively. The LC-MS/MS method has also been successfully applied to 60 maize samples, which were collected from Shaanxi Province of China. Twenty-four of the total 60 samples (40%) were contaminated with at least 1 of these 9 mycotoxins. Occurrence of mycotoxins were 6.7%, 1.7%, 3.3%, 6.7%, 1.7%, 23.3%, and 3.3% for AFB1, AFB2, OTA, ZEA, DON, FB1, and T2-toxin, respectively. The results demonstrated that the procedure was suitable for the simultaneous determination of these mycotoxins in maize matrix. Practical Application A sensitive LC-MS/MS method was developed for the simultaneous determination of aflatoxins (AFB1, AFB2, AFG1, AFG2), OTA, DON, ZEA, FB1, and T2-toxin in maize; OASIS HLB cartridge was adopted for cleanup of mycotoxins. This method will have potential analytical applications for other cereals and can be performed for routine analysis in laboratories.

This study aimed to investigate the adsorption of patulin from apple juice by Ca-alginate-activated carbon (Ca-alginate-AC) beads. The capacity of patulin was determined by high-performance liquid chromatography. The results showed that Ca-alginate-AC beads have significant ability to reduce patulin from contaminated apple juice. Furthermore, the adsorption process did not affect the quality of apple juice. The effects of contact time, initial patulin concentration, adsorbent dose, and temperature were assessed. The removal percentage of patulin increased with contact time, adsorbent dose, and temperature. A reduction was also noted to bind patulin at increased levels of contamination. The equilibrium data were fitted to Langmuir, Freundlich, and Temkin isotherm models and the isotherm constants were calculated at different temperatures. The adsorption equilibrium was best described by the Freundlich isotherm (R(2) > 0.990). The pseudo 1st-order model was found to describe the kinetic data satisfactorily. Thermodynamic parameters such as standard Gibbs free energy (ΔG◦◦), standard enthalpy (ΔH◦), and standard entropy (ΔS◦) were evaluated. The results showed that the adsorption was spontaneous and endothermic nature.

Use of organic solvents to extract phenolic compounds from plants may result in environmental pollution and cause health problems in persons. Replacing organic extraction solvents by green extracting agents without affecting the extraction yield is one of the most pressing problems to be solved. The aim of this study is to evaluate the capacity of β-cyclodextrin (β-CD) to recover phenolic compounds from tea leaves. The extract obtained using the ethanol/water mixture presented the highest total phenolic content, followed by those obtained using β-CD solution and water. HPLC analysis of the extracts showed that the addition of β-CD to the extracting agent had a selective effect on the extraction of epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). The extraction yield of EGCG and ECG using 15 g/L β-CD were higher than that obtained using water and 50% ethanol. Molecular docking results indicated that the molecules of EGCG and ECG were more inclined to interact with β-CD than epigallocatechin, epicatechin, and gallocatechin. The impact of β-CD concentration, temperature, and time on EGCG and ECG extraction from tea leaves was investigated and the maximum amount of EGCG (118.7 mg/g) and ECG (54.6 mg/g) were achieved when extracted with 25 g/L aqueous β-CD solution at 60 °C for 60 min. The present study indicates that aqueous β-CD can be used as an alternative to organic solvents to recover EGCG and ECG from tea leaves.

This work was undertaken to evaluate the microbiological characteristics and antioxidant and physiological activities in kiwifruits (Actinida deliciosa var. Qinmei) with/without cinnamaldehyde (C1) and citral (C2) fumigation treatments (5 μL/L) during 0, 3, 6, 9, and 12 d of storage at 4 °C. Essential oils (EOs) treatment lowered the total viable counts, yeast, and mold to 1.54, 2.36, and 2.05 log CFU/g, respectively. Moreover, EOs improved the antioxidant activities of kiwifruit. They enhanced phenolics and flavonoids content in fruit tissue by 49.48% at day 3 and 56.93% at day 6, respectively. In addition, ascorbic acid in treated groups had the lower losing rate. Similarly, MDA (malondialdehyde), H

A sort of specific polyclonal anti-Alicyclobacillus antibody was generated by immunizing New Zealand white rabbits, and a sensitive indirect enzyme-linked immunosorbent assay (ELISA) was developed for Alicyclobacillus detection in apple juice. A set of experimental parameters such as concentration of antigen, dilutions of the antibody and goat anti-rabbit IgG-horseradish peroxidase conjugate, selection of the blocking reagent, incubation time, and temperature was optimized. The cross-reactivity of the antibody was evaluated by ELISA and the result was consistent with Western blot analysis. The detection limit of the ELISA was about 10(5) colony forming units (CFU)/mL in apple juice samples. Samples were detected by ELISA and conventional culture method, and the ELISA results gave a good agreement with the results obtained by plating on Alicyclobacillus acidoterrestris medium agar. ELISA takes a total detection time of 6 to 7 h, which is less than the time of conventional techniques requiring more than 24 to 48 h. These results indicated that the established ELISA was a potential useful analytical method for detection of Alicyclobacillus in apple juice.

Alicyclobacillus spp. are thermoacidophilic, spore-forming bacteria, some of which cause spoilage in pasteurized and heat-treated apple juice products through the production of guaiacol. It would be helpful if a rapid method to detect and discriminate Alicyclobacillus strains was available. A simple and rapid sample preparation method using nitrocellulose membrane filter (NMF) and a single reflection horizontal attenuated total reflection (HATR) accessory with Fourier transform infrared (FT-IR) was developed here. Fourier transform infrared (FT-IR) spectroscopy was used and tested on 8 Alicyclobacillus strains (KF, WAC, NWN-13501, NWN-12697, NWN-12654, NWN-10682, 1016, 1101). A linear discriminant analysis (LDA) was established to discriminate Alicyclobacillus strains. The sample preparation method could successfully separated strains into different groups by principal component analysis (PCA). High identification accuracy (95%) was achieved with the LDA model. Practical Application: The method developed in the paper can be used to discriminate different Alicyclobacillus strains from each other making it possible to easily determine whether the strain of Alicyclobacillus present is associated with juice spoilage.

Yeasts and yeast-like fungal isolates were recovered from apple orchards and apple juice processing plants located in the Shaanxi province of China. The strains were evaluated for osmotolerance by growing them in 50% (w/v) glucose. Of the strains tested, 66 were positive for osmotolerance and were subsequently identified by 26S or 5.8S-ITS ribosomal RNA (rRNA) gene sequencing. Physiological tests and RAPD-PCR analysis were performed to reveal the polymorphism of isolates belonging to the same species. Further, the spoilage potential of the 66 isolates was determining by evaluating their growth in 50% to 70% (w/v) glucose and measuring gas generation in 50% (w/v) glucose. Thirteen osmotolerant isolates representing 9 species were obtained from 10 apple orchards and 53 target isolates representing 19 species were recovered from 2 apple juice processing plants. In total, members of 14 genera and 23 species of osmotolerant isolates including yeast-like molds were recovered from all sources. The commonly recovered osmotolerant isolates belonged to Kluyveromyces marxianus, Hanseniaspora uvarum, Saccharomyces cerevisiae, Zygosaccharomyces rouxii, Candida tropicalis, and Pichia kudriavzevii. The polymorphism of isolates belonging to the same species was limited to 1 to 3 biotypes. The majority of species were capable of growing within a range of glucose concentration, similar to sugar concentrations found in apple juice products with a lag phase from 96 to 192 h. Overall, Z. rouxii was particularly the most tolerant to high glucose concentration with the shortest lag phase of 48 h in 70% (w/v) glucose and the fastest gas generation rate in 50% (w/v) glucose.

This study aimed to investigate the adsorption of patulin from apple juice by Ca-alginate-activated carbon (Ca-alginate-AC) beads. The capacity of patulin was determined by high-performance liquid chromatography. The results showed that Ca-alginate-AC beads have significant ability to reduce patulin from contaminated apple juice. Furthermore, the adsorption process did not affect the quality of apple juice. The effects of contact time, initial patulin concentration, adsorbent dose, and temperature were assessed. The removal percentage of patulin increased with contact time, adsorbent dose, and temperature. A reduction was also noted to bind patulin at increased levels of contamination. The equilibrium data were fitted to Langmuir, Freundlich, and Temkin isotherm models and the isotherm constants were calculated at different temperatures. The adsorption equilibrium was best described by the Freundlich isotherm (R(2)0.990). The pseudo 1st-order model was found to describe the kinetic data satisfactorily. Thermodynamic parameters such as standard Gibbs free energy (ΔG◦◦), standard enthalpy (ΔH◦), and standard entropy (ΔS◦) were evaluated. The results showed that the adsorption was spontaneous and endothermic nature.

A reliable and sensitive liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous determination of aflatoxins (AFB1 , AFB2 , AFG1 , and AFG2 ), ochratoxin A (OTA), deoxynivalenol (DON), zearalenone (ZEA), fumonisin B1 (FB1 ), and T2-toxin in maize. The samples were first extracted using acetonitrile: water: acetic acid (79 : 20 : 1), and then further cleaned-up using OASIS HLB cartridge. Optimum conditions for the extraction and chromatographic separation were investigated. The mean recoveries of mycotoxins in spiked maize ranged from 68.3% to 94.3%. Limits of detection and quantification ranged from 0.01 to 0.64 μg/kg and from 0.03 to 2.12 μg/kg, respectively. The LC-MS/MS method has also been successfully applied to 60 maize samples, which were collected from Shaanxi Province of China. Twenty-four of the total 60 samples (40%) were contaminated with at least 1 of these 9 mycotoxins. Occurrence of mycotoxins were 6.7%, 1.7%, 3.3%, 6.7%, 1.7%, 23.3%, and 3.3% for AFB1 , AFB2 , OTA, ZEA, DON, FB1 , and T2-toxin, respectively. The results demonstrated that the procedure was suitable for the simultaneous determination of these mycotoxins in maize matrix.

Apple juice is a complex mixture of volatile and nonvolatile components. To develop discrimination models on the basis of the volatile composition for an efficient classification of apple juices according to apple variety and geographical origin, chromatography volatile profiles of 50 apple juice samples belonging to 6 varieties and from 5 counties of Shaanxi (China) were obtained by headspace solid-phase microextraction coupled with gas chromatography. The volatile profiles were processed as continuous and nonspecific signals through multivariate analysis techniques. Different preprocessing methods were applied to raw chromatographic data. The blind chemometric analysis of the preprocessed chromatographic profiles was carried out. Stepwise linear discriminant analysis (SLDA) revealed satisfactory discriminations of apple juices according to variety and geographical origin, provided respectively 100% and 89.8% success rate in terms of prediction ability. Finally, the discriminant volatile compounds selected by SLDA were identified by gas chromatography-mass spectrometry. The proposed strategy was able to verify the variety and geographical origin of apple juices involving only a reduced number of discriminate retention times selected by the stepwise procedure. This result encourages the similar procedures to be considered in quality control of apple juices. Practical Application: This work presented a method for an efficient discrimination of apple juices according to apple variety and geographical origin using HS-SPME-GC-MS together with chemometric tools. Discrimination models developed could help to achieve greater control over the quality of the juice and to detect possible adulteration of the product.