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关键词： Anaerobic digestion   PBAT/PLA   Food waste   Degradation   Microbial analysis  

摘要： Degradation of bioplastics in food-waste-treating anaerobic digestion (AD) plants is becoming an increasingly concerning issue as they are inevitably mixed with food waste during the waste collection process. The aim of this study was to assess the degradation of PBAT/PLA based biopolymer bags during mesophilic and thermophilic AD, co-digested with food waste, and subsequent aerobic post-treatment. After the AD process, no discernable biological degradation was observed for all of the PBAT/PLA polymers. The comparison of FTIR, XRD, TG analysis and contact angle analysis between raw and degraded PBAT/PLA polymer revealed structural changes after anaerobic incubation. Subsequent aerobic treatment facilitated the degradation of the PBAT/PLA polymers from thermophilic AD, which was attributed to the polymer-degrading microorganisms Brevundimonas and Sphingobacterium. Physical disintegration of the PBAT/PLA polymer was observed under thermophilic conditions. Those undegraded polymer fragments could affect digestate quality and increase the risk of releasing microplastics into the environment.

关键词： Glutathione   Heavy metal stress   Homeostasis   Metallothionein   Organic acids   Phytochelatins   Transporters  

摘要： An increase in technological interventions and ruthless urbanization in the name of development has deteriorated our environment over time and caused the buildup of heavy metals (HMs) in the soil and water resources. These heavy metals are gaining increased access into our food chain through the plant and/or animal-based products, to adversely impact human health. The issue of how to restrict the entry of HMs or modulate their response in event of their ingress into the plant system is worrisome. The current knowledge on the interactiveregulatory role and contribution of different physical, biophysical, biochemical, physiological, and molecular factors that determine the heavy metal availability-uptake-partitioning dynamics in the soil-plant-environment needs to be updated. The present review critically analyses the interactive overlaps between different adaptation and tolerance strategies that may be causally related to their cellular localization, conjugation and homeostasis, a relative affinity for the transporters, rhizosphere modifications, activation of efflux pumps and

关键词： Antioxidants  

摘要： The physicochemical, antioxidant, and polyphenolic attributes of microencapsulated freeze-dried kinnow peel extract powder using maltodextrin as wall material were investigated. The total phenolic, flavonoid, and antioxidant content of fresh peel extract were 24.51 mg GAE/g, 9.12 mg Quercetin/g, and 81.53% scavenging activity, respectively. The maltodextrin prepared from broken rice starch competes well with those commercial types. The microencapsulated kinnow peel powders across feed solutions 10%, 15%, and 20% total soluble solids (TSS) significantly differed (p < .05)by yield, water absorption, water solubility, swelling capacity, bulk density, antioxidant activity, moisture, water activity, hygroscopicity, water solubility index, swelling capacity, and color. The low cohesiveness and good flowability were respectively demonstrated by Carr index (1.18) and Hausner ratio (15.21) values. The intestinal fluid released more polyphenolic components over the gastric medium. Overall, the maltodextrin as a wall material would effectuate a beneficial microencapsulation process. Practical application Maltodextrin is among the polysaccharides used as wall materials with desirable characteristics. Despite the previous studies that have evidenced the role of maltodextrin, relevant information about those specifically obtained from broken rice starch for use in the microencapsulation of citrus peel extract is scant. In this work, we demonstrated the maltodextrin specifically obtained from broken rice starch to be a promising wall material for the microencapsulated citrus peel extract powder.

关键词： citric acid-esterified starch   digestibility   estimated glycaemic index   high-pressure cooking processing   resistant starch  

摘要： The effect of high-pressure cooking processing (HPCP) on the physicochemical structure and in vitro digestion of citric acid-esterified starches made from different materials (water chestnut, sweet potato, potato, corn) was investigated. HPCP increased the swelling and solubility of sweet potato esterified starch (SPSC) and potato esterified starch (PSC) and decreased the swelling and solubility of water chestnut esterified starch (WCSC) and corn esterified starch (CSC). Fourier-transform infrared spectroscopy revealed that the short-range structure of starches was more orderly. Differential scanning calorimetry and X-ray diffraction were used to determine the crystallisation peaks and enthalpy of different starches after HPCP. HPCP decreased the SPSC and PSC content of resistant starches (RS). However, HPCP showed no significant effect on the RS and estimated glycaemic index of WCSC and CSC. The results showed that the RS in WCSC and CSC had stronger thermal stability and was more suitable to be added to heat-processed foods.

ISBN: (纸本)9787122401601

关键词： Bottom sediment porosity   Bottom sediment surface area   Bottom sediment negative surface charge   Organic carbon   Sorption capacity   Ecotoxicity  

摘要： The sorption mechanisms of the trace elements in bottom sediment are not fully understood. The study aim was to analyse the effect sorption capacity of bottom sediments on the content of trace elements and the bottom sediment ecotoxicity. The study found higher content of trace elements caused higher potential toxicity of bottom sediments. However, the PCA analysis indicated that ecotoxicity to Heterocypris incongruens was not related to the trace element content in the sediments. It was found that some of the physicochemical properties of bottom sediments determine the behavior of the test organism. The study revealed a strong relationships between the properties of bottom sediments and trace element sorption, which results from significant differences in the carbonate and organic matter contents. The obtained relationships showed a significant role in trace element sorption of negatively dissociating functional groups (carboxyl, phenolic, alcohol, and carbonyl groups) of Cha, Cfa, Cnh and DOC fraction and of clay minerals. Positive correlation between the metal content and the volume of ultramicropores, cryptopores and residual pores suggest that these pore groups contain reactive sites capable of effective element sorption. In contrast, larger pores turned out to be of marginal importance in trace elements sorption, probably participating only in their migration within the bottom sediment structure. An understanding of the above factors will provide comprehensive information on the fate of trace elements in aquatic systems.

关键词： Pumpkin   Starch   Structural properties   Functional properties   Digestibility  

摘要： Winter squash (Cucurbita maxima Duch.) and pumpkin (Cucurbita moschata Duch. ex Poir.) are widely consumed in the world. Empirical evidences showed that their cooked texture was related to the starch content and probably starch properties. In this study, starches were extracted from 2 winter squash cultivars (Yinli and Heili) and 1 pumpkin cultivar (Miben) popularly cultivated in China. The mature fruits of three cultivars contained 1.05-6.47% (fresh weight) starch with different granule sizes (d (0.5) 9.51-15.18 mu m). Starches from winter squash and pumpkin had polyhedral and spherical shape granules with amylose content varied from 21.35% to 30.17%. All starches exhibited B-type crystalline structure. The relative crystallinity ranged from 26.15% to 31.31%, and the IR absorbance ratios of 1022/995 cm(-1) and 1045/1022 cm(-1) ranged from 0.759 to 0.806 and from 0.565 to 0.607, respectively, among 3 cultivars. SAXS pattern indicated 9.59-9.80 nm D-Bragg for these starches. The M-w was highest (5.03 x 10(7) g/mol) in Miben starch but lowest (3.64 x 10(7) g/mol) in Heili starch. All starches had identical amylopectin branch chain distributions but varied in average chain length and f(b1) and f(b2) chains. The gelatinization temperature (T-o, T-p, T-c) and enthalpy change (Delta H) were lowest in Heili starch and highest in Miben starch. The peak, trough, final and setback viscosities varied from 4468 to 6266 cP, 3116 to 4259.5 cP, 4075 to 6073 cP, and 787 to 1813 cP, respectively. All starch granules showed strong resistance to enzymatic hydrolysis. Yinli and Miben starches had higher RS content in starch pastes and retrograded gels than Heili starch.

ISBN: (纸本)9787122403384

关键词： large yellow croaker   quality   thawing   ultrasonic treatment  

摘要： Ultrasonic treatment (UT) was used to thaw large yellow croaker in this study, and the effect of various ultrasonic power levels on the quality of large yellow croaker was evaluated after thawing. The effects of ultrasonic on water holding capacity (WHC), moisture distribution, thiobarbituric acid-reactive substance (TBARs), total volatile base nitrogen (TVB-N), ATP degradation (related to K value), surface color change, free amino acid (FAA) content, total sulfhydryl group (SH) content, Fourier transform infrared absorption spectra (FT-IR), fluorescence emission spectra, and microscopic observations of large yellow croaker myofibrillar proteins were investigated. The thawing times of the control sample, 200UT, 240UT, 280UT, and 320UT samples were 1750, 1190, 810, 580, and 570 s, respectively, which indicated that ultrasonic radiation could improve thawing efficiency. Additionally, ultrasonic thawing maintained better freshness and color and inhibited lipid oxidation. Compared with fresh samples, the TVB-N of large yellow croaker thawed by ultrasonication increased by 12.68%, and the K value increased by 0.9%. The 240UT sample had tightly arranged myofibrils and fewer changes in the structures of myogenic fibrillar proteins than the fresh samples, and the SH content of 240UT was decreased by 8.17%. Use of excessive ultrasonic power (320 W) damaged the protein microstructure and the microstructure of large yellow croaker. In conclusion, sample 240UT maintained the quality of large yellow croaker better with minimal damage, which is recommended for rapid thawing. Practical Application Ultrasonic waves improve the thawing efficiency of large yellow croaker and maintain the freshness and color of the fish. According to results, sample 240UT exhibited slight changes in the structure of the myofibril protein, but excessive ultrasonic power destroyed the microstructure and protein structure. Appropriate ultrasonic treatment to the thawing of fish has good prospects.

关键词： antioxidant   bulk oil   emulsion   prooxidant   tocopherols  

摘要： Lipid oxidation is a major concern in the food, cosmetic, and pharmaceutical sectors. The degradation of unsaturated lipids affects the nutritional, physicochemical, and organoleptic properties of products and can lead to off-flavors and to the formation of potentially harmful oxidation compounds. To prevent or slow down lipid oxidation, different antioxidant additives are used alone or in combination to achieve the best possible efficiency with the minimum possible quantities. In manufactured products, that is, heterogeneous systems containing lipids as emulsions or bulk phase, the efficiency of an antioxidant is determined not only by its chemical reactivity, but also by its physical properties and its interaction with other compounds present in the products. The antioxidants most widely used on the industrial scale are probably tocopherols, either as natural extracts or pure synthetic molecules. Considerable research has been conducted on their antioxidant activity, but results regarding their efficiency are contradictory. Here, we review the known mechanisms behind the antioxidant activity of tocopherols and discuss the chemical and physical features that determine their efficacy. We first describe their chemical reactivity linked with the main factors that modulate it between efficient antioxidant capacity and potential prooxidant effects. We then describe their chemical interactions with other molecules (phenolic compounds, metals, vitamin C, carotenes, proteins, and phospholipids) that have potential additive, synergistic, or antagonist effects. Finally, we discuss other physical parameters that influence their activity in complex systems including their specific interactions with surfactants in emulsions and their behavior in the presence of association colloids in bulk oils.