Effects of rice protein, soy isolate protein, and whey concentrate protein on the digestibility and physicochemical properties of extruded rice starch.

Protein, as the second major component in starchy foods, is crucial for its influence on the physicochemical properties and digestibility of starch. However, the effect of different sources of protein on starch digestibility is still unclear. In this paper, the effects of different sources of proteins (rice protein: RP, soybean isolate protein: SPI, and whey concentrate protein: WPC) on structural features, digestibility, and enzyme activity of extruded rice starch were investigated. The addition of all three proteins reduced the starch digestibility of extrudates. Native SPI and WPC suppressed amyloglucosidase activity, and all three proteins exhibited stronger amyloglucosidase inhibition when hydrolyzed. The rheological properties and Fourier transform infrared spectroscopy results revealed the exogenous proteins and starch interacted through non-covalent bonds and improved the ordered structures in the extrudates. The extrusion process also facilitated the formation of a V-type structure. The sum of SDS and RS content of extrudates was negatively correlated with the content of leached amylose and positively correlated with the ratio of 1047/1022 cm-1 . These findings suggest that the inclusion of exogenous proteins during extrusion can affect starch digestibility through mechanisms such as the interaction with starch molecules, as well as the inhibition of amylase activity. PRACTICAL APPLICATION: This result indicated that the addition of protein during extrusion not only increased the nutritional value of the extrudate, but also decreased the starch digestibility. Extrusion technology can efficiently produce extruded products with protein, expanding further applications of protein in food and providing new healthy staple food options for special populations, such as diabetic and overweight people.

Application of starch-based nanoparticles and cyclodextrin for prebiotics delivery and controlled glucose release in the human gut: a review.

Starches are a major constituent of staple foods and are the main source of energy in the human diet (55-70%). In the gastrointestinal tract, starches are hydrolyzed into glucose by α-amylase and α-glucosidase, which leads to a postprandial glucose elevation. High levels of blood glucose levels over sustained periods may promote type 2 diabetes mellitus (T2DM) and obesity. Increasing consumption of starchy foods with a lower glycemic index may therefore contribute to improved health. In this paper, the preparation and properties of several starch-based nanoparticles (SNPs) and cyclodextrins (CDs) derivatives are reviewed. In particular, we focus on the various mechanisms responsible for the ability of these edible nanomaterials to modulate glucose release and the gut microbiome in the gastrointestinal tract. The probiotic functions are achieved through encapsulation and protection of prebiotics or bioactive components in foods or the human gut. This review therefore provides valuable information that could be used to design functional foods for improving human health and wellbeing.

Effects of whey protein on the in vitro digestibility and physicochemical properties of potato starch.

The aim of this study was to examine the effect of whey protein isolate (WPI) on the digestibility and physicochemical properties of potato starch (PS) after heat treatment. WPI reduced the digestibility of PS and increased the order and aggregation structure of gelatinized PS. Examination of the rheological properties of the PS-WPI mixed system before and after adding different chemicals (sodium chloride, urea, and sodium dodecyl sulfate) indicated an involvement of hydrogen bonds and hydrophobic interactions in the PS-WPI gelatinization system. The pasting properties, swelling power, and thermal properties indicated that WPI suppressed the swelling and gelatinization of PS. The addition of WPI reduced the amylose leaching rate from the starch granules, indicating that the presence of exogenous protein could prevent amylose diffusion from the starch granules. Native WPI and its hydrolysate also inhibited amyloglucosidase activity. These findings indicated that the mechanism by which WPI reduces PS digestion involves hydrophobic interactions and hydrogen bonding between WPI and PS, as well as enzyme activity inhibition.

The effect of Vaccinium bracteatum Thunb. leaves addition on antioxidant capacity, physicochemical properties, and in vitro digestibility of rice extrudates.

Vaccinium bracteatum Thunb.leaves (VBTL) are a traditional Chinese herbal medicine with potential natural pigments and antioxidants. Its application information on extrusion is limited. In this study, to increase the usage of foods containing VBTL, rice-based extrudates with VBTL were investigated. The extrusion was performed at a wide temperature range (60-140°C) and with different VBTL supplementations (3%-10%). The extrudates with 10% VBTL showed a significant decrease in total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity upon extrusion. TPC and TFC increased with the rise of barrel temperature. The VBTL color was stable during the wide-temperature extrusion process. The bioactivities of the extrudates were positively correlated with the VBTLsupplement (R = 0.943-0.989). In addition, different addition levels of VBTL significantly changed the water absorption index (WAI), water solubility index (WSI), pasting properties, and in vitro starch digestibility of the extrudates. Moreover, extrudates with 3% VBTL showed the highest WAI and peak viscosity but the lowest in vitro starch digestibility. These results may suggest that rice extrudates with a low supplement of VBTL have an acceptable color and may be used as functional additives for high antioxidant and low glycemic response diets. PRACTICAL APPLICATION: The results showed that the Vaccinium bracteatum Thunb. leaves (VBTL) color and antioxidation were stable during the wide-temperature extrusion process. Extrusion processing can be used to enlarge the usage of VBTL and simplify its traditional processing method. Applying VBTL to the process of extrusion appears to be a suitable method of producing value-added and low glycemic response extrudates.

Batch fermentation kinetics of acetoin produced by Bacillus subtilis HB-32.

OBJECTIVES: The aim of this work was to study the changes of bacterial cell growth, acetion formation and glucose consumption with fermentation time during batch cultivation. RESULTS: A mathematical model of cell growth, product synthesis, and substrate consumption changes with time during the batch cultivation of acetion was established. By analyzing the fitting curve of the kinetic model, it is found that the calculated value of the model fits well with the experimental value, and the fitting model R2 is greater than 0.98. CONCLUSIONS: The kinetic model established in this experiment can better reflect the batch cultivation process of acetion.

2-Keto-D-gluconic acid and prodigiosin producing by a Serratia marcescens.

Microbial fermentation has become the main method to produce target compound. In this study, a 2-Keto-D-gluconic acid (2-KGA) producing mutant strain was obtained by mutation with rational screening methods. Meanwhile, prodigiosin was produced when the nitrogen source in the medium was changed to peptone and its fermentation conditions were evaluated to achieve high-efficient accumulation. The mutant strain SDSPY-136 was firstly identified as Serratia marcescens by morphological observation and 16S rDNA sequencing. The 2-KGA synthetic capacity of S. marcescens SDSPY-136 was evaluated by shake fermentation with 110 g/L glucose as substrates. For fermentation, 2-KGA yield, conversation rate and purity of SDSPY-136 reached 104.60 g/L, 95.10%, 99.11% in 72 h. The red pigment was extracted from the fermentation broth using acidic methanol and identified as prodigiosin by FT-IR. The optimal conditions were as follows: glycerol 20 g/L, peptone 20 g/L, MgSO415 g/L, pH 6.0, a 2% (v/v) inoculum, 30 °C and 200 rpm of shaking culture. Eventually, prodigiosin reached a yield of 9.89 g/Lafter shake culturing for 50 h under this condition. The mutant S. marcescens SDSPY-136 was shown to be promising for 2-KGA and prodigiosin production and a suitable object for prodigiosin metabolism research of S. marcescens.

Drivers of dynamic evolution in provincial production water usage: perspective of regional relevance.

With the advancement of industrialization and urbanization, the issue of water shortage has become a bottleneck for China's economic development. Based on the structural decomposition analysis and multi-regional input-output tables of China in 2002 and 2012, this paper explores the drivers of the change in China's production water usage from the regional relevance perspective. Results show a significant increase in China's production water usage during the study period. The relationship between production water usage and per capita GDP shows an inverted U-shaped curve, and the economic scale by provinces has been improved, while the trend of production water usage differs. There are rapid increases in production water usage in economically developing provinces, while it is falling sharply in developed provinces. The crucial factors promoting its growth are changes in consumption level, population scale, and regional economic patterns. The technical effect is the most important factor in curbing the growth, followed by effects of final demand sectoral and distribution structure. The provinces and sectors with more production water usage shows higher technical and final demand effects. Therefore, it is necessary to promote water-saving activities, enhance the water-saving technical effect, and optimize final demand structure to promote economic growth with low-water usage.

A trade-related CO2 emissions and its composition: Evidence from China.

Trade-related CO2 emissions has been widely studied in existing research and them have mainly calculated the CO2 emissions embodied in overall trade; however, China's domestic value chain (DVC) has developed rapidly, and different regions have different emissions effects due to different trade patterns. This study divides Chinese interregional trade into four trade patterns from the perspective of domestic production fragmentation. Then we develop a decomposition model of the interregional trade-related CO2 emissions and pollution heaven hypothesis (PHH) of different trade patterns based on China's interregional input-output table for 2002 to 2010. Finally, we explore the influencing factors of the changes of environmental effects using structural decomposition analysis method. The results show that from 2002 to 2010, the volume of CO2 emissions embodied in interregional trade increased significantly with the share of CO2 emissions induced by traditional trade in intermediate products always representing a major proportion but which still underwent a downward trend. Interregional trade activities increase China's CO2 emissions, and the PHH holds at the national level. Among them, trade in final products is conducive to reducing national CO2 emissions while the other three patterns of interregional trade are opposite. In particular, the balance of avoided CO2 emissions (BAC) in trade related to the DVC is positive, meaning that the DVC is polluting. In addition, domestic trade activities of the central region, northwestern region, and northern coast are not conducive to reducing regional and national CO2 emissions while the southern coast and northeastern region are opposite.

Structural path analysis of China's coal consumption using input-output frameworks.

In-depth study of the key sectors and supply chain paths driving coal consumption in China is valuable for effectively formulating coal reduction and replacement policies to achieve sustainable development. This study conducted a structural path analysis, based on the latest publicly available input-output tables and energy use data provided by the World Input-Output Database, to trace China's coal consumption transmission throughout its entire supply chain. The results indicate that investment, exports, and household consumption are important factors in coal consumption. "Electricity, Gas and Water Supply" is a critical sector for, largely indirect, coal consumption. The path of "Electricity, Gas and Water Supply→ intermediate sectors→ Construction→ Investment" accounts for the bulk of coal consumption in China. The node path analysis shows that the 2-node transmission paths, starting from Construction and ending with "Other Non-Metallic Mineral" and "Basic Metals and Fabricated Metal" are important sources of coal consumption induced by investment demand. The 1-node path of "Basic Metals and Fabricated Metal" is an important path for coal consumption induced by export demand. The 1-node path of "Electricity, Gas and Water Supply" is an important path for coal consumption caused by household consumption demand. In order to effectively implement coal reduction and replacement policies, China should control coal consumption in these key sectors and channels and optimize intermediate input and energy use structures.

Re-examining the embodied air pollutants in Chinese exports.

China is the world's largest exporter and may release lots of air pollutants to produce exported commodities due to taking coal as its main source of energy. Processing exports play a significant role in Chinese exports, yet previous studies of embodied air pollutants in Chinese exports failed to distinguish processing exports from normal exports. This paper investigates the effect of trade heterogeneity on the estimation of embodied emissions by re-examining the embodied air pollutants in Chinese exports based on an extended non-competitive input-output table that distinguishes processing from normal exports. The results show that processing exports generate 22.81% of the value added embodied in gross exports and 16.48% of the emissions embodied in gross exports. The embodied air pollutants in Chinese exports would be overestimated by 12%-22% without accounting for trade heterogeneity. Unequal distributions of export-related air pollutants and value added exist among different sectors. In particular, Manufacturing of Electronics and Communication Equipment sector induces 39.56% of embodied emissions in processing exports, and 41.78% of which are generated by Production and Supply of Electric Power and Steam Hot Water sector. China's restrictions on processing exports should focus not only on the direct emissions generated by each sector but also on the emissions embodied in domestic supply chains.