Structure, thermal stability, physicochemical and functional characteristics of insoluble dietary fiber obtained from rice bran with steam explosion treatment: Effect of different steam pressure and particle size of rice bran.

Rice bran was modified by steam explosion (SE) treatment to investigate the impact of different steam pressure (0.4, 0.8, 1.2, 1.6, and 2.0 MPa) with rice bran through 60 mesh and rice bran pulverization (60, 80, and 100 mesh) with the steam pressure of 1.2 MPa on the structure, thermal stability, physicochemical and functional characteristics of insoluble dietary fiber (IDF) extracted from rice bran. IDF with SE treatment from scanning electron microscopy images showed a porous honeycomb structure, and lamellar shape in IDF became obvious with the increase of steam pressure. The relative crystallinity and polymerization degree of crystalline regions in IDF from rice bran with SE treatment from X-ray diffraction analysis were decreased. Differential scanning calorimetry results showed that thermal stability of IDF with SE treatment increased with the increase of crushing degree. The results of FT-IR also suggested that some glycosidic and hydrogen bonds in IDF could be broken, and some cellulose and hemicellulose were degraded during SE process. The physicochemical and functional characteristics of IDF, including water-holding capacity, oil-holding, glucose adsorption capacity, α-amylase and pancreatic lipase inhibition capacity were decreased with the increase of steam pressure and crushing degree. The swelling and nitrite adsorption capacities of IDF were increased first and then decreased with the increase of steam pressure. The physicochemical and functional characteristics of IDF from rice bran were improved after SE treatment, which might provide references for the utilization of IDF from rice bran with SE treatment.

[Analysis of Industrial VOCs Emission Inventory and Countermeasures in Xiamen].

Based on data from industrial activities and environmental surveys in the six districts of Xiamen, the emission inventory of industrially sourced volatile organic compounds (VOCs) from eight industries in the six districts of Xiamen was calculated for 2019 by applying the emission factor analysis method. The spatial distribution pattern of VOC emission intensity in the six districts of Xiamen was analyzed. VOCs treatment technologies applied in the industries in the VOCs emission inventory were analyzed and countermeasures for improving VOC control were proposed based on the survey of the industries. The results showed that the total VOCs production and VOCs emission from industrial sources in Xiamen was 16027.88 t and 5514.58 t in 2019, respectively. Among them, the VOCs emission from Haicang, Tong'an, Xiang'an, and Jimei districts outside Xiamen Island were 1648.35, 2111.13, 667.52, and 750.48 t, respectively. Fewer VOC emissions from Xiamen Island were observed, which included 292.42 and 44.68 t from Huli and Siming districts, respectively. Except for the Huli District, the spatial distribution of emissions showed a spatial characteristic that the VOCs emission intensities outside Xiamen Island are higher than that of Xiamen Island. Among the eight industries in Xiamen, VOCs emissions were mainly from coating, printing, chemical, and rubber industries, which accounted for 51.21%, 20.18%, 13.63%, and 10.67%, respectively, of the total emissions. The analytic results of the VOCs waste gas disposal technique in Xiamen indicate that, from the perspective of source control, enterprises can effectively control the generation and emission of the VOCs at the source by using low (zero) raw materials. For the terminal disposal procedure, the actual disposal efficiency of UV photolysis/photocatalysis, low-temperature plasma, and biological methods are all lower than 80%, and that of the combined technique of adsorption and catalytic combustion, and the combustion method are both higher than 90%.

[Air Microbial Pollution and Health Risk of Urban Black Odorous Water].

Aiming at the possihle air microbial pollution of urban black odorous water the contamination characteristics of bacteria, fungi and total microbe as well as health risks of different types of population within certain distance from the urban black odorous water were studied. The results showed that hbcteria and fungi pollution was primary within offshore 200 m; under near calm condition, there was an aggregation phenomenon of microorganisms within offshore 20 m; the concentrations of bacteria, fungi and total microbe were the highest in the morning, the middle at noon, and the lowest in the afternoon; within offshore 200 m, the width of black odorous water was significantly correlated with the concentrations of bacteria, fungi and total microorganisms; the microbial health risk of residents mainly existed in the offshore 100 m range; at the same offshore distance, the short-term exposure health risk to children was the greatest, followed by women, men to a minimum.

[Effects of exogenous nitric oxide on physiological characteristics of longan (Dimocarpus longana) seedlings under acid rain stress].

This paper studied the effects of exogenous nitric oxide donor sodium nitroprusside (SNP) on the chlorophyll content, antioxidant enzyme activities, and osmotic regulation substances of longan (Dimocarpus longana 'Fuyan') seedlings under acid rain (pH 3.0) stress. Under the acid rain stress, the seedling leaf superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities and chlorophyll, soluble protein and soluble sugar contents decreased obviously, while the leaf malondialdedyde content had a remarkable increase, suggesting the toxic effect of the acid rain on the seedlings. Exogenous nitric oxide had dual nature on the physiological characteristics of longan seedlings under acid rain stress. Applying 0.1-0.5 mmol x L(-1) of SNP improved the SOD, POD and CAT activities and the chlorophyll, soluble protein and soluble sugar contents significantly, and decreased the malondialdedyde content. Low concentrations SNP reduced the oxidative damage caused by the acid rain stress, and 0.5 mmol x L(-1) of SNP had the best effect. Under the application of 0.5 mmol x L(-1) of SNP, the total chlorophyll, soluble protein, and soluble sugar contents and the SOD, POD and CAT activities increased by 76.0%, 107.0%, 216.1%, 150. 0%, 350.9% and 97.1%, respectively, and the malondialdedyde content decreased by 46.4%. It was suggested that low concentration (0.1-0.5 mmol x L(-1)) SNP could alleviate the toxic effect of acid rain stress on longan seedlings via activating the leaf antioxidant enzyme activities and reducing oxidative stress, while high concentration SNP (1.0 mmol x L(-1)) lowered the mitigation effect.

[Determination of benzo[a]pyrene in mainstream smoke by solid-phase extraction and gas chromatography-mass spectrometry].

A novel method is suggested for the determination of benzo[a]pyrene in mainstream smoke. Extraction of Cambridge pads was cleaned up with methanol/n-heptane extraction system and silica solid-phase extraction (SPE). The eluted solution containing benzo[a]pyrene was evaporated gently to complete dryness with N2 flow, then reconstituted in 200 microL ethyl acetate for determination with gas chromatography-mass spectrometry selected ion monitoring (SIM). The proposed method had good results and precision for the separation of pyrene in complex matrices.