Effects of a Composite Soil Amendment on the Quality of Pak Choi(Brassica rapa L. Chinensis Group) Growing in Pb-contaminated Soils

In the present study, a pot experiment was carded out to investigate the effects of a composite soil amendment at different levels （0, 600, 900 and 1 200 mg/kg） on the soil organic matter content, pH, Pb uptake and nutritional quality of pak choi （Brassica rapa L. Chinensis Group） grown in the soils contaminated by four levels （800, 1 200, 1 600 and 2 000 mg/kg） of Pb. The results showed that 900 mg/kg soil amendment increased the soil organic matter content by 24.19%- 60.00%, but had no significant influence on soil pH. Comparing with control （without amendment application）, the security and nutritional quality of pak choi were obviously improved by applying the soil amendment. In detail, 900 mg/kg soil amendment improved the content of Vc of pak choi growing in 800, 1 200, 1 600 and 2 000 mg/kg Pb-contaminated soils by 13.27%-69.30%, the content of soluble sugar by 54.17%- 87.50%, the dry matter weight by 28.36%-33.39%, and decreased the content of Pb by 19.11%-35.72% and the content of crude fiber by 20.83%-31.03%, respectively. These data indicated that the composite amendment can be used for the in situ repair of Pb-contaminated soils, and the recommended dosage is 900 mg/kg.

Studies on the Simultaneous Determination of Cr(Ⅲ)and Cr(Ⅵ)by Ion Chromatography(IC)

The research aimed to develop and validate an ion chromatography method for the simultaneous analysis of Cr(Ⅲ) and Cr(Ⅵ)from pumpkin. A new analytical method based on ion chromatography techniques was developed by the Cr(Ⅲ) pre-column derivatization and Cr(Ⅵ) post-column derivatization. The ion chromatography condition was optimized and the detection sensitivity was improved. Cr(Ⅲ) and Cr(Ⅵ) were determined by 365 and 530 nm,respectively. The temperature of water bath,the heating time for pre-column derivatization,and the flow rate of post-column derivative liquid were screened on the basis of single factor experiment,the effects of various factors were determined by the method of L16( 43) orthogonal experiment design. Considering the results of orthogonal experiments and the variation tendency of peak area under different factors,the optimum derivatization conditions were chose as follows: the flow rate of post-column derivative liquid is0. 5 m L/min,the temperature of water bath for pre-column derivatization is 100 ℃ and the heating time is 5 min. The conditions were optimized by means of orthogonal experiments under the p H of leacheate ranged from 6. 5 to 6. 8 and the I-concentration of 5 mmol/L. Under optimized derivatization conditions,the detection limits for Cr(Ⅲ) and Cr(Ⅵ) were 0. 17 and 0. 019 mg,respectively. And the average recoveries of Cr(Ⅲ) in pumpkin were in the range of 82%-85%. Results indicated that pumpkin does not contain Cr(Ⅵ) according to this ion chromatography method of simultaneously determination for Cr(Ⅲ) and Cr(Ⅵ).

Effects of fresh-cut and storage on glucosinolates profile using broccoli as a case study

Glucosinolates(GLS) contribute to the unique flavour, nutrition, and plant defence of the Cruciferous vegetables. Understanding the GLS changes through postharvest processing is essential for defined preservation. In this study, four different fresh-cut types, whole flower(W),floret(F), quarterly cut floret(QF) and shredded floret(FS) of broccoli, were stored for 0, 1, 2 and 3 day(s) to explore GLS responses to postharvest treatments. As a result, seven GLS were identified, mainly including glucoraphanin(RAA), neoglucobrassicin(NEO), and glucobrassicin(GBC)and accounting for 52.69%, 20.12% and 14.99% of the total GLS(21.92 ± 0.48) μmol · g ^(-1 )DW, respectively. FS had the sharpest decrease in GLS after three days of storage(6.55 ± 0.37) μmol · g-1DW, while QF had the least(10.16 ± 0.33) μmol · g ^(-1 )DW. All GLS components decreased over storage, except for 4-methoxyglucobrassicin(4 ME) in FS and QF, suggesting its key role in serious wound defence. The results suggested certain postharvest approaches influenced the flavour and nutrition of broccoli.

Recoloring tomato fruit by CRISPR/Cas9-mediated multiplex gene editing

Fruit color is an important horticultural trait,which greatly affects consumer preferences.In tomato,fruit color is determined by the accumulation of different pigments,such as carotenoids in the pericarp and f lavonoids in the peel,along with the degradation of chlorophyll during fruit ripening.Since fruit color is a multigenic trait,it takes years to introgress all color-related genes in a single genetic background via traditional crossbreeding,and the avoidance of linkage drag during this process is difficult.Here,we proposed a rapid breeding strategy to generate tomato lines with different colored fruits from red-fruited materials by CRISPR/Cas9-mediated multiplex gene editing of three fruit color-related genes(PSY1,MYB12,and SGR1).Using this strategy,the red-fruited cultivar‘Ailsa Craig’has been engineered to a series of tomato genotypes with different fruit colors,including yellow,brown,pink,light-yellow,pink-brown,yellow-green,and light green.Compared with traditional crossbreeding,this strategy requires less time and can obtain transgene-free plants with different colored fruits in less than 1 year.Most importantly,it does not alter other important agronomic traits,like yield and fruit quality.Our strategy has great practical potential for tomato breeding and serves as a reference for improving multigene-controlled traits of horticultural crops.

Analysis on Composition and Content of Glucosinolates in Broccoli Flowers and Leaves

Glucosinolate composition and content were evaluated in flowers and leaves of 12 different broccoli varieties. The results indicated that there were 9 glucosinolates in broccoli,namely Glucoiberin(IBE); Progoitrin(PRO);Sinigrin(SIN);Glucoraphanin(RAA);Gluconapin(NAP);4-Hydroxyglucobrassicin(4OH);Glucobrassicin(GBC);4-Methoxyglucobrassicin(4ME);Neoglucobrassicin(NEO).Total glucosinolate content in flowers was 1-5 times higher than in leaves. The predominant glucosinolate in broccoli was glucoraphanin.

Glucosinolate Variation in Turnip (Brassica rapa L.) at Different Growing Stages

The seed, leaf and root parts of three turnip （ Brassica rapa L.） cultivars were analyzed for glucosinolates. The component and concentration of glucosinolates in the three cultivars were also analyzed at different growing stages. Eight kinds of glucosinolates were tested in turnip. They were PRO, NAP, 4OH, GBN, GBC, NAS, 4ME and NEO, respectively. The contents and kinds of glucosinolates varied at different growing stages. The content of NAS was the highest in the seed, GBC and NEO contents were the highest in the seedling, GBN and NEO contents were the highest in the leaf, while the highest NAS content was in the root.

Nondestructive determination of IMP content in chilled chicken based on hyperspectral data combined with chemometrics

This study was conducted to investigate the potential of hyperspectral imaging technique(900-1700 nm)for nondestructive determination of inosinic acid(IMP)in chicken.Hyperspectral images of chicken flesh samples were acquired,and their mean spectra within the images were extracted.The quantitative relationship between the mean spectra and reference IMP value was fitted by partial least squares(PLS)regression algorithm.A PLS model(MAS-PLS)built with moving average smoothing(MAS)spectra showed better performance in predicting IMP content,leading to correlation coefficients(RP)of 0.951,root mean square error(RMSEP)of 0.046 mg/g,and residual predictive deviation(RPD)of 3.152.Regression coefficient(RC),successive projections algorithm(SPA),stepwise,competitive adaptive reweighted sampling(CARS),and uninformative variable elimination(UVE)were used to select the optimal wavelengths to optimize the MAS-PLS model.Based on the 18 optimal wavelengths(907.14,917.02,918.67,926.90,930.20,936.78,956.54,1004.28,1135.89,1211.56,1302.07,1367.94,1397.60,1488.31,1680.17,1683.49,1686.80 and 1695.10 nm)selected from MAS spectra by SPA,the MAS-SPA-PLS model was built with R_(P) of 0.920,RMSEP of 0.056 mg/g and RPD of 3.220,which was similar to the MAS-PLS model.The overall study indicated that hyperspectral imaging in the 900-1700 nm range combined with PLS and SPA could be used to predict the IMP content in chicken flesh.

Quick assessment of chicken spoilage based on hyperspectral NIR spectra combined with partial least squares regression

Pseudomonas spp.and Enterobacteriaceae are dominant spoilage bacteria in chicken during cold storage(0°C-4°C).In this study,high resolution spectra in the range of 900-1700 nm were acquired and preprocessed using Savitzky-Golay convolution smoothing(SGCS),standard normal variate(SNV)and multiplicative scatter correction(MSC),respectively,and then mined using partial least squares(PLS)algorithm to relate to the total counts of Pseudomonas spp.and Enterobacteriaceae(PEC)of fresh chicken breasts to predict PEC rapidly.The results showed that with full 900-1700 nm range wavelength,MSC-PLS model built with MSC spectra performed better than PLS models with other spectra(RAW-PLS,SGCS-PLS,SNV-PLS),with correlation coefficient(RP)of 0.954,root mean square error of prediction(RMSEP)of 0.396 log10 CFU/g and residual predictive deviation(RPD)of 3.33 in prediction set.Based on the 12 optimal wavelengths(902.2 nm,905.5 nm,923.6 nm,938.4 nm,946.7 nm,1025.7 nm,1124.4 nm,1211.6 nm,1269.2 nm,1653.7 nm,1691.8 nm and 1693.4 nm)selected from MSC spectra by successive projections algorithm(SPA),SPA-MSC-PLS model had RP of 0.954,RMSEP of 0.397 log10 CFU/g and RPD of 3.32,similar to MSC-PLS model.The overall study indicated that NIR spectra combined with PLS algorithm could be used to detect the PEC of chicken flesh in a rapid and non-destructive way.

Application and optimization of solid-state fermentation process for enhancing polygalacturonase production by Penicillium expansum

Penicillium expansum 3.5425 was applied in solid-state fermentation(SSF)of agricultural wastes for polygalacturonase biosynthesis.Among various carbon additives,apple pomace was most suitable for the biosynthesis of polygalacturonase(1440.57 U/g).Optimization of medium parameters using rotational orthogonal design(ROD)experiment combined with optimal fermentation conditions resulted in a 2.72-fold increase in the polygalacturonase production.By using ammonium sulphate precipitation,ion-exchange and gel-permeation chromatography,the polygalacturonase produced by P.expansum 3.5425 was finally purified which had specific activity of 19269 U/mg and molecular weight of 30 kDa.The enzyme was remarkably active in the pH range of 3-5 and at 50℃,which makes it more acceptable in the industrial application.Besides,partially purified polygalacturonase(875.15 U/mL)was used for apple juice clarification and the clarity at 0.4 mL/kg was maximum,which reveals a great potential of polygalacturonase in food industry.

LW-NIR hyperspectral imaging for rapid prediction of TVC in chicken flesh

Total viable count(TVC)is often used as an important indicator for chicken freshness evaluation.In this study,112 fresh chicken flesh samples were acquired after slaughtered and their hyperspectral images were collected in the LW-NIR(900-1700 nm)range.The full LW-NIR spectra(486 wavebands)within the images were extracted and applied to related to reference TVC values measured in different storage periods,using partial least squares regression(PLSR)algorithm,resulting in high correlation coefficients(R)and low root mean square errors(RMSE),for either raw spectra or pretreatment spectra.By using regression coefficients(RC)method,20,18,17 and 20 optimal wavebands were respectively selected from raw spectra,baseline correction(BC)spectra,Savitzky-Golay convolution smoothing(SGCS)spectra and standard normal variate(SNV)spectra and applied for the optimization of original full waveband PLSR model.By comparison,RC-PLSR model based on the SGCS spectra showed a better performance in TVC prediction with RC of 0.98 and RMSEC of 0.35 log10 CFU/g in calibration set,and RP of 0.98 and RMSEP of 0.44 log10 CFU/g in prediction set.At last,by transferring the best RC-PLSR model,the dynamic TVC change during the storage was visualized by color maps to indicate the TVC spoilage degree.The overall study revealed that LW-NIR hyperspectral imaging combined with PLSR could be used to predict the freshness of chicken flesh.

Mining hyperspectral data for non-destructive and rapid prediction of nitrite content in ham sausages

Accurate and rapid determination of nitrite contents is an important step for guaranteeing sausage quality.This study attempted to mine hyperspectral data in the range of 900-1700 nm for non-destructive and rapid prediction of nitrite contents in sausages.The average spectra of 156 samples were collected to relate to the measured nitrite values by partial least squares(PLS)regression.Optimal wavelengths were respectively selected by successive projections algorithm(SPA)and regression coefficients(RC)to simplify the PLS model.The results indicated that PLS model established with 15 optimal wavelengths(900.5 nm,907.1 nm,908.8 nm,912.1 nm,915.4 nm,920.3 nm,922.0 nm,941.7 nm,979.6 nm,1083.2 nm,1213.2 nm,1353.0 nm,1460.2 nm,1595.6 nm and 1699.9 nm)selected by SPA had better performance with r C,r CV,r P of 0.92,0.89,0.89 and RMSEC,RMSECV,RMSEP of 0.41 mg/kg,0.89 mg/kg,0.49 mg/kg,respectively,for calibration set,cross-validation and prediction set.It was concluded that hyperspectral data could be mined by PLS&SPA for realizing the rapid evaluation of nitrite content in ham sausages.