Force-induced tail-autotomy mitochondrial fission and biogenesis of matrix-excluded mitochondrial-derived vesicles for quality control.

Mitochondria constantly fuse and divide for mitochondrial inheritance and functions. Here, we identified a distinct type of naturally occurring fission, tail-autotomy fission, wherein a tail-like thin tubule protrudes from the mitochondrial body and disconnects, resembling autotomy. Next, utilizing an optogenetic mitochondria-specific mechanostimulator, we revealed that mechanical tensile force drives tail-autotomy fission. This force-induced fission involves DRP1/MFF and endoplasmic reticulum tubule wrapping. It redistributes mitochondrial DNA, producing mitochondrial fragments with or without mitochondrial DNA for different fates. Moreover, tensile force can decouple outer and inner mitochondrial membranes, pulling out matrix-excluded tubule segments. Subsequent tail-autotomy fission separates the matrix-excluded tubule segments into matrix-excluded mitochondrial-derived vesicles (MDVs) which recruit Parkin and LC3B, indicating the unique role of tail-autotomy fission in segregating only outer membrane components for mitophagy. Sustained force promotes fission and MDV biogenesis more effectively than transient one. Our results uncover a mechanistically and functionally distinct type of fission and unveil the role of tensile forces in modulating fission and MDV biogenesis for quality control, underscoring the heterogeneity of fission and mechanoregulation of mitochondrial dynamics.

Combined effects of chemical dispersant and suspended minerals on the dispersion process of spilled oil.

The dispersion process of spilled oil is an important concern for the effective disposal of oil spills. The dispersed oil concentration and oil droplets size distribution were studied through a wave tank test under the application of chemical dispersant and suspended minerals. The results indicated that dispersant and minerals increased the dispersed oil concentration and the effect of dispersant was more significant, and they had a synergistic effect on oil dispersion. When dispersant and minerals were applied together, the volume mean diameter of oil droplets decreased in the first 30 min, then increased and reached a maximum value at 90-120 min, and decreased again. Moreover, suspended minerals could inhibit the coalescence of oil droplets. This study can afford data support for oil spill emergency response that occurs in inshore or estuaries.

Reduction of 5-hydroxymethylfurfural formation by flavan-3-ols in Maillard reaction models and fried potato chips.

BACKGROUND: 5-Hydroxymethylfurfural (HMF) is regarded as a thermal process contaminant in foods. Six flavan-3-ol fractions were isolated or semisynthesized from sorghum, cranberry and grape seed. Their unit compositions, interflavan linkages and degree of polymerization were characterized. The aim of this study was to investigate the effect of flavan-3-ols on the formation of HMF in chemical reaction models and fried potato chips. RESULTS: Results showed that all flavan-3-ols significantly mitigated the HMF formation at concentrations of 50, 100 and 200 µg mL-1 in the chemical model system, and the inhibition was positively related to dose. Using the food model, HMF content was reduced by about 50% when potato chips were soaked in an optimal concentration of 0.1 mg mL-1 flavan-3-ol solutions before frying. Based on the same mass concentration, B-type flavan-3-ols mitigated more HMF than A-type, and oligomeric proanthocyanidins had stronger inhibitory activity than polymers. At suitable addition levels (0.01-0.1 mg mL-1 ), the browning of auto-oxidized flavan-3-ols under high temperature compensated the anti-browning effect along with the supression of the Maillard reaction; therefore, the color of fried potato chips was not affected. CONCLUSION: This study demonstrates that flavan-3-ols could be effective additives for reducing HMF levels in fried potato chips without changing sensory properties. © 2018 Society of Chemical Industry.

Potential relation between starch granule-associated proteins and retrogradation properties of buckwheat starch.

To elucidate the effect of starch granule-associated proteins (SGAPs) on retrogradation properties of buckwheat starch, the retrogradation properties of Tartary buckwheat starch (TBS) and common buckwheat starch (CBS) before and after removal of SGAPs were systematically investigated, with wheat starch (WS) as reference. A significant decrease in gel strength of starches and density of starch aggregates were observed after removing SGAPs. The results were in line with the changes in retrogradation enthalpy of starches and short-range ordered structure of starch aggregates. After removing SGAPs, the retrogradation enthalpy of TBS decreased from 4.16 J/g to 3.74 J/g, CBS decreased from 4.05 J/g to 3.35 J/g and WS decreased from 3.27 J/g to 2.81 J/g, respectively. Taken together the results of LF-NMR, FTIR and rheological analysis, it can be concluded that SGAPs could promote the hydrogen bond interactions between starch molecules by competitively binding with water molecules, enhancing the rearrangement of starch molecules and forming a more ordered structure. Overall, the study suggested that the presence of SGAPs could enhanced the interaction between starch molecules chains, thus accelerated the retrogradation process. The research results provide more information about SGAPs in buckwheat starch and support further study for manipulation of starch properties.

Folding during sheeting improved qualities of dried noodles through gluten network proteins.

The texture properties after cooking for 12 min were selected to optimize the sheeting parameters, and the results were verified using the comprehensive quality of dried noodles. The distribution of water, characteristics of gluten protein, and interaction between gluten network and starch were analyzed to clarify the mechanism of the quality of dried noodles. Results showed that the optimal folding angle was 45°, under this condition, the largest anti-extension displacement perpendicular to the rolling direction and the smallest cooking loss were obtained. The hardness and smoothness of cooked noodles increased by about 14% to 17%. Further, the transverse relaxation time of strongly bound water significantly decreased, while the relative content and binding strength increased. The hydrogen bonds and α-helix contents increased by about 68.8% and 53.1%, respectively. Folding and sheeting enhanced the combination of starch granules and gluten network causing, decreased in the average length and porosity of the gluten network. It is depicted from the results that the method of optimizing the sheeting process based on the texture of dried noodles cooked for 12 min was feasible. And the 45° folding and sheeting could help to improve the quality of dried noodles.

Epicatechin-Promoted Formation of Acrylamide from 3-Aminopropionamide Via Postoxidative Reaction of B-Ring.

The role of thermally generated 3-aminopropionamide as an intermediate in acrylamide formation in the Maillard reaction has been well established. Herein, the effect of epicatechin on the conversion of 3-aminopropionamide into acrylamide under oxidative conditions was investigated at 160-220 °C. Epicatechin promoted acrylamide generation and 3-aminopropionamide degradation. The stable isotope-labeling technique combined with UHPLC-Orbitrap-MS/MS analysis showed adduct formation between 3-aminopropionamide and the oxidized B ring of epicatechin to form a Schiff base. This initially formed Schiff base could directly degrade to acrylamide, undergo reduction or dehydration to other intermediates, and subsequently generate acrylamide. Based on accurate mass analysis, five intermediates with intact or dehydrated C rings were tentatively identified. Furthermore, reaction pathways were proposed that were supported by the changes in the levels of adducts formed during heating. To the authors' knowledge, this study is the first to reveal pathways through which flavanols promoted the formation of acrylamide in Maillard reactions.

High-amylose maize starch: Structure, properties, modifications and industrial applications.

High-amylose maize refers to a special type of maize cultivar with a 50 %-90 % amylose content of the total starch. High-amylose maize starch (HAMS) is of interest because it possesses unique functionalities and provides many health benefits for humans. Therefore, many high-amylose maize varieties have been developed via mutation or transgenic breeding approaches. From the literature reviewed, the fine structure of HAMS is different from the waxy and normal corn starches, influencing its gelatinization, retrogradation, solubility, swelling power, freeze-thaw stability, transparency, pasting and rheological properties, and even in vitro digestion. HAMS has undergone physical, chemical, and enzymatical modifications to enhance its characteristics and thereby broaden its possible uses. HAMS has also been used for the benefit of increasing resistant starch levels in food products. This review summarizes the recent developments in our understanding of the extraction and chemical composition, structure, physicochemical properties, digestibility, modifications, and industrial applications of HAMS.

Effect of sodium carbonate on the properties of seventy percent of Tartary buckwheat composite flour-based doughs and noodles and the underlying mechanism.

The impact of Na2 CO3 on the properties of doughs and noodles containing 70% Tartary buckwheat flour was investigated. Low-field 1 H nuclear magnetic resonance showed the mobility of water in the doughs significantly declined with the addition content of alkali from 0% to 0.9%. Na2 CO3 promoted the transformation from free sulfhydryl groups to disulfide bonds in doughs because the sulfhydryl groups in cysteine preferred to form thiolate anion and then oxidate under alkaline conditions. As for non-covalent chemical interactions, a significant increase of hydrogen bonds and a decrease of hydrophobic interactions were observed after Na2 CO3 addition. Quantitative analysis of microstructure showed that more uniform and denser gluten networks with higher branching rate and shorter average protein length and width formed in the doughs with 0.3%-0.6% of Na2 CO3 . The aggregated glutenin macropolymer and enhanced protein structure led to significantly stronger tensile of Tartary buckwheat dough sheets, which could meet the demand of continuous processing in the factory. Dough with alkali had higher swelling power and pasting viscosities, contributing to higher water absorption, and improved textural attributes of cooked noodles. This study demonstrated the possibility of adding Na2 CO3 at a moderate level for promoting the sheeting, cooking, and eating properties of high Tartary buckwheat flour composite noodles.

Modelling dried noodle quality: Contribution of starch and protein physicochemical properties of 32 wheat cultivars.

30 mainstream wheat breeds from China and 2 from Australian were evaluated to analyze the correlation between grain quality traits, protein/starch properties and the comprehensive quality of fine dried noodles (FDN), with a multiple regression analysis conducted to establish predictive equations. Results showed FDN quality was both determined by the protein content and quality, as well as the starch properties, especially pasting characteristics. The balance between gluten strength and starch swelling characteristics was a key point to produce high quality FDN. Zhoumai32 and APW were found to be excellent cultivars for FDN production. Gluten content and index, SDS sedimentation value, dough extensibility, setback and peak viscosity could be served as indicators for specializing FDN flour. The established predictive equations could well explain over 60% of the variation in noodle color, cooking time, hardness, chewiness, and extensibility. These results were hoped to be a fundamental step towards developing the related standards or regulations for specializing FDN flour and rapid noodle quality prediction.

Investigating the positive effects of wrap-around resting on the qualities of semi-dried noodles through the quantitative analysis of gluten network.

In this study, the dough sheet wrap-around was employed to assist the resting process of the semi-dried noodles comparatively with dough crumbs resting and common dough sheet resting. The gluten network quantitative analysis was carried out to investigate the positive impacts of dough sheet wrap-around resting in semi-dried noodles production. The results showed that the dough sheet wrap-around resting improved the color, surface smoothness, cooking qualities, and eating qualities of semi-dried noodles. Dough sheet wrap-around resting for 30 min significantly (p < 0.05) increased the surface smoothness and chewiness by 47.08% and 44.35%, respectively. Furthermore, increased extensibility in the transverse direction of dough sheets generated superior processing properties. The average protein length and width of dough sheets experienced a considerable (p < 0.05) reduction. In contrast, the branching rate was markedly (p < 0.05) augmented, which meant the distribution of gluten network was more uniform and denser. The total protein length and the number of protein network lines both significantly (p < 0.05) increased. The number of transverse protein network lines increased by 28.70%, which was much higher than that (5.77%) of the longitudinal direction. Conclusively, at the optimal dough sheet wrap-around time of 30 min, the higher-quality semi-dried noodles were produced by enhancing the gluten network.

Formation and sedimentation of oil-mineral aggregates in the presence of chemical dispersant.

The formation and sedimentation of oil-mineral aggregates (OMAs) is the major method to transport spilled oil to the seafloor. In this study, the formation and sedimentation experiments of OMA using montmorillonite and four crude oils were performed in a wave tank in the presence of chemical dispersant. Most of the formed OMAs were droplet OMAs, and single droplet OMA would aggregate into multiple ones under the action of the dispersant. The size of the oil droplets trapped in the OMA increased with time and was larger for the oil with higher viscosity. The sinking velocities of OMAs formed in this study were between 100-1200 µm s-1 and they were positively correlated with their diameter. The density of OMA was of the same order as that of the crude oil that formed them. An increase in the dispersant dosage could promote the formation of OMAs. The oil content in OMAs was higher for the denser oil in the presence of a dispersant. The maximum oil trapping efficiency of OMAs was 48.05%. This study provides fundamental data on the formation kinetics of OMAs.

Exploring the underlying mechanisms on starch restricted swelling-induced reduction in digestion rate of buckwheat noodles.

To elucidate the slower digestion rate of buckwheat starch in noodles-matrix, the digestion kinetics of Tartary (TBN) and common (CBN) buckwheat starch reconstituted noodles as well as wheat starch reconstituted noodles (WSN) were compared using a simulated oral-gastric-intestinal in vitro digestion. The swelling degree of starch in cooked noodles can be expressed by quantitative analysis of microstructure. The digestion rate of WSN was 2.3-2.9 times higher as compared to CBN and TBN. The swelling degree of starch in CBN and TBN was restricted due to their denser structure, which led to the reduction of the contact area between starch molecules and amylase. Additionally, the stronger water retention ability and higher cohesiveness of CBN and TBN could hinder the water migration, and ultimately affect the accessibility of enzymes. These results demonstrated that the restricted swelling of starch in CBN and TBN during cooking was the important reason for their slower digestibility.

Improving the cold water swelling properties of oat starch by subcritical ethanol-water treatment.

The granular cold water swelling oat starch was prepared by subcritical ethanol-water, and the changes of properties and structure on oat starch were investigated. The oat starch was modified at the temperature of 95 °C and ethanol concentration of 48% and showed a higher cold water swelling ability of 22.58 g/g, whereas native oat starch was 6.73 g/g. Modified oat starch granule was kept intact, and it was swollen when dispersing in the water. The gelatinization enthalpy declined to 0 J/g. The surface of modified oat starch granules was honeycomb and porous observed by scanning electron microscope. The X-ray diffraction showed the A-type crystal decreased and the V-type crystal increased, and the result was quantitatively confirmed by solid-state 13C NMR spectroscopy. The ratio of 1047 cm-1/1022 cm-1 (determined by Fourier transform infrared spectroscopy) of modified oat starch was decreased. The molecular weight distribution of modified oat starch was slightly reduced, and the amylose content increased from 26.18% to 31.68%, and only a small amount of carbohydrates leached during the modification. Subcritical ethanol-water modification improved the cold water swelling ability of oat starch. The starch crystals changed from A-type to V-type provide a potential mechanism of subcritical ethanol-water modified oat starch.

Effects of oil properties on the formation of oil-particle aggregates at the presence of chemical dispersant in baffled flask tests.

The formation of oil-particle aggregates (OPA) is the major sedimental pathway of spilled oil, which can bring great harm to both the benthic communities and marine environment. In this paper, effects of GM-2 chemical dispersant and oil properties on the formation of OPA was investigated by the EPA baffled flask test. The addition of dispersant can promote the formation of OPA from montmorillonite and five test oils obviously. With the increase of the dispersant dosage, the size of trapped oil in OPA increased and the density of OPA decreased. The dispersant can increase the kinematic viscosity of crude oil, and high viscosity of the oil is advantageous for the formation of OPA. The oil-seawater interfacial tension is reduced after the addition of dispersant, which makes oil dispersed into the water column easier. A kinematic equation of dispersed oil concentration attenuation was modified by introducing the oil property coefficient ß. The modified empirical equation can calculate the mass of oil in sunken OPA in oil spill accidents.

Improvements of dried noodles qualities using two-stage resting: Explanation from macro and micro perspectives.

The purpose of this study was to elucidate the effects of two-stage resting (dough crumbs and dough sheets resting) on the quality of dried noodles. An improvement mechanism was explored according to the texture of dough sheets, gluten network, and microstructure of cooked noodles. After two-stage resting, the extensibility of dough sheets, the contents of glutenin macro polymer (GMP), and disulfide bonds (S-S) increased significantly (p < .05), whereas the content of sulphydryl group (-SH) significantly declined. From the perspective of microstructure, the average length and width of dough sheets protein experienced a significant reduction (p < .05); however, the branching rate, the number of protein lines, and the total length of the protein lines significantly increased (p < .05). Furthermore, the average network line length and width of cooked noodles were significantly reduced as the branching rate rose (p < .05); meanwhile, the number of holes significantly increased while the average area significantly decreased (p < .05). Overall, the two-stage resting has improved the quality of dried noodles and contributed to a more uniform and compact gluten network distribution.

In vitro starch digestibility of buckwheat cultivars in comparison to wheat: The key role of starch molecular structure.

The objective of this study was to compare the in vitro digestibility of different buckwheat and wheat starch cultivars and establish the relationship between digestibility and structure of buckwheat starch. Structure of starches were analyzed with size exclusion chromatography and fluorophore-assisted capillary electrophoresis. Results showed that the amylose content of Tartary buckwheat starch (TBS) and common buckwheat starch (CBS) was 3-4% lower than that of wheat starch. However, no significant difference in the digestibility was found between them. The fast digestion rate coefficient of TBS was negatively correlated with the amount of long amylopectin chains (24 < DP ≤ 36), and the total digested starch percentage of CBS was negatively correlated with the amount of medium-long amylopectin chains (13 < DP ≤ 24). This suggests that the digestibility of fully gelatinized starch had no association with the botanical sources but may be more influenced by starch structure.

Conformational equilibrium and hydrogen bonding in liquid 2-phenylethylamine explored by Raman spectroscopy and theoretical calculations.

2-Phenylethylamine (PEA) is the simplest aromatic amine neurotransmitter, as well as one of the most important. In this work, the conformational equilibrium and hydrogen bonding in liquid PEA were studied by means of Raman spectroscopy and theoretical calculations (DFT/MP2). By changing the orientation of the ethyl and the NH(2) group, nine possible conformers of PEA were found, including four degenerate conformers. Comparison of the experimental Raman spectra of liquid PEA and the calculated Raman spectra of the five typical conformers in selected regions (550-800 and 1250-1500 cm(-1)) revealed that the five conformers can coexist in conformational equilibrium in the liquid. The NH(2) stretching mode of the liquid is red-shifted by ca. 30 cm(-1) relative to that of an isolated PEA molecule (measured previously), implying that intermolecular N-H···N hydrogen bonds play an important role in liquid PEA. The relative intensity of the Raman band at 762 cm(-1) was found to increase with increasing temperature, indicating that the anti conformer might be favorable in liquid PEA at room temperature. The blue shift of the band for the bonded N-H stretch with increasing temperature also provides evidence of the existence of intermolecular N-H···N hydrogen bonds.

Highland barley starch (Qingke): Structures, properties, modifications, and applications.

Highland barley (HB) is mainly composed of starch, which may account for up to 65% of the dry weight to the kernel. HB possesses unique physical and chemical properties and has good industrial application potential. It has also been identified as a minor grain crop with excellent nutritional and health functions. Highland barley starch (HBS) features a number of structural and functional properties that render it a useful material for numerous food and non-food applications. This review summarizes the current status of research on the extraction processes, chemical composition, molecular fine structures, granular morphology, physicochemical properties, digestibility, chemical and physical modifications, and potential uses of HBS. The findings provide a comprehensive reference for further research on HBS and its applications in various food and non-food industries.

Sandwich-type sheeting improved the processing and eating qualities of potato noodles.

A technology called sandwich-type sheeting was used to produce noodles with potato flakes. The technical parameters of sheeting were first optimized. Then the processing and eating qualities of potato noodles made with sandwich-type sheeting and conventional sheeting were compared. Results showed that the optimal moisture of inner-layer dough and outer-layer dough was 41 and 37%, respectively. The suitable ratio of the thickness of inner layer to that of outer layer was 3:1. The tensile strength of the sandwich-type dough sheet was 1.285 times higher than that of conventional dough sheet. The cooking loss of the sandwich-type noodles was 37.0% lower than that of conventional noodles, and the adhesiveness decreased by 51.0%. In the sandwich-type noodles, the compact gluten network structure of outer wheat layer prevented the leaching of soluble substances in the inner layer added with potato flakes, improving the cooking and eating qualities of potato noodles.

Insoluble dietary fibre scavenges reactive carbonyl species under simulated physiological conditions: The key role of fibre-bound polyphenols.

Polyphenols bound to insoluble fibre may scavenge reactive carbonyl species by surface chemical reactions. In the present study, this hypothesis was tested by investigating the ability of bound-polyphenol rich insoluble dietary fibre (BP-IDF) isolated from blackberry pomace, red cabbage, and wheat bran in scavenging carbonyl compounds. Three BP-IDF showed high scavenging efficacy for glyoxal, methylglyoxal, acrolein and malondialdehyde. Upon in vitro digestion, trapping capacity was retained by the insoluble fraction suggesting that carbonyl trapping activity and physiological relevance needs to be extended to undigestible materials. The removal of bound polyphenols from the polysaccharide backbones through alkaline and acidic treatment reduced by up to 90% of trapping capacity of BP-IDF. Moreover, methylglyoxal-polyphenol adducts were detected bound to blackberry pomace BP-IDF after hydrolysis. These findings demonstrated that polyphenols bound to IDF scavenged reactive carbonyl species and highlighted the physiological relevance of BP-IDF in limiting carbonyl stress along all the gastrointestinal tract.