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Characteristics and mechanism of Leuconostoc citreum as a novel bioflocculant for starch granules in starch production
2023
Xuan Wang | Pamela Owusu Osei | Lei Rao | Xiaomeng Wu | Xiaojun Liao
The Leuconostoc citreum SJ-57 strain isolated from the sweet potato starch production showed great potential as a microbiological flocculant, but its underlying flocculation mechanisms are yet unknown. In this study, infrared spectroscopy and thermodynamic analysis were performed to elucidate the short-range and long-range interactions between Leuc. citreum SJ-57 and starch granules, revealing that bacteria cells bond starch granules via metal-bridging ionic bonds. A high repulsive energy barrier of ~8 × 10−18 J must be overcome to initiate the flocculation process. Heat, protease, lipase, lysozyme, dextranase, and guanidine hydrochloride were used to treat the bacterial cell, confirming that its flocculation ability originated from surface proteins, including GW structural domain proteins, DnaK, GroEL, elongation factor Tu, and lysozyme M1. The primary flocculation mechanisms of Leuc. citreum was proposed to provide a deep understanding of microbiological flocculants and a foundation for future industrial applications in starch production.
Показать больше [+] Меньше [-]Discrimination capacity analysis of FTIR-PCA and EEM-PARAFAC on dandelion tissues extracts
2023
Guoqing Li | Hui Zou | Yilun Chen
Dandelion root contains triterpenoids, polyphenols and flavonoids, dandelion leaf is rich in polyphenols, flavonoids, flavonoids glycosides, and dandelion flower mainly contains flavonoids, among other substances. These different substance content leads to specific benefits and function effects of each part. Fourier transform infrared spectroscopy, three-dimensional fluorescence spectroscopy and related multivariate statistical methods are widely used to determine sample characteristics, but limited research focuses on the substance difference and characteristics in dandelion tissues. In this paper, Fourier transform infrared spectra-principal component analysis and three-dimensional fluorescence spectroscopy-parallel factor analysis were conveyed to analyze dandelion stem, leaf, root and flower tissue extracts, for determining the substance species and content difference among dandelion tissues and evaluating the discrimination capacity of these analysis methods. The Fourier transform infrared spectroscopy of root was distinct from others, and the two principal component models could distinguish dandelion stem and flower, but failed to differentiate leaf and root; while the excitation and emission matrix showed that stem and flower, leaf and root had similar intensity band distribution but different fluorescence intensity, and the parallel factor analysis results proved that one- and three-component models cannot differentiate the tissues of stem and flower, leaf and root, since the fluorescent compounds (polyphenol, flavonoid etc.) structure and content were similar in different tissues. These results indicated that Fourier transform infrared-principal component analysis might be a useful method when various fluorescent compounds exist.
Показать больше [+] Меньше [-]Development of κ-carrageenan hydrogels with mechanically stronger structures via a solvent-replacement method
2023
Yichuan Wang | Xinna Zhang | Yanxiang Gao | Fang Yuan | Like Mao
Strong κ-carrageenan (KC) hydrogels were fabricated via solvent replacement with sorbitol, and the effects of KC mass fraction and solvent replacement on the structural characteristics encapsulation capability of the hydrogels were evaluated. Microstructural observation showed that the 3D network structures of hydrogels exhibited a complete and continuous skeleton. FTIR spectra of KC hydrogels revealed the formation of intermolecular hydrogen bonds after sorbitol replacement. The stability against heating and freeze-thawing of hydrogels was enhanced due to the addition of sorbitol and the rise in KC mass fraction. The hydrogel with 1.5 wt% KC after sorbitol replacement presented the best stability. Frequency sweep tests suggested that storage modulus of the samples were influenced by sorbitol replacement and KC concentration. Swelling tests revealed that the hydrogels after replacement with a higher KC content (1.25, 1.50 wt%) presented higher swelling capacity, and they were more stable in alkaline and acidic solutions. When epigallocatechin gallate (EGCG) was incorporated within the hydrogels, the hydrogels after sorbitol replacement offered higher protection capability. The information obtained in this study indicated that sorbitol replacement strengthened KC hydrogels, and they could act more appropriately as accountable carriers for bioactives.
Показать больше [+] Меньше [-]Distinct roles of the IRE1α arm and PERK arm of unfolded protein response in arachidonic acid-induced ferroptosis in hepatocytes
2023
Han Zhang | Kai Han | Shutao Yin | Lihong Fan | Hongbo Hu | Chong Zhao
Ferroptosis is a distinct form of cell death that is driven by iron-dependent phospholipid peroxidation. Polyunsaturated fatty acids (PUFAs), particularly arachidonic acid (AA) and adrenal acid (AdA), are most prone to lipid peroxidation, which induces ferroptosis and affects the function of cell membranes. In this study, we discovered that AA induces ferritinophagy in hepatocytes, a selective form of autophagy that degrades ferritin, triggering unstable iron overload. Mechanistically, AA enhances cellular uptake of bound iron by up-regulating transferrin receptor 1 (TfR1). Additionally, AA induces endoplasmic reticulum stress (ER stress) and simultaneously activates two of its branches, pancreatic ER kinase (PERK) and inositol-requiring enzyme 1 (IRE1). Notably, PERK and IRE1 appear to play distinct roles in inducing ferritinophagy. Inhibition of PERK reduced the AA-induced increase of Fe2+ by alleviating ferritinophagy, while inhibition of IRE1 further exacerbated ferroptosis by activating ferritinophagy. Furthermore, there seems to be an interaction between the signaling pathways of ER stress, and inhibition of IRE1 exacerbates AA-induced ferritinophagy by further activating the PERK signaling pathway, thereby exacerbating the extent of cell death. Collectively, our findings suggest that iron overload is involved in AA-induced hepatocyte ferroptosis and that this process is regulated by ER stress-mediated ferritinophagy. This study suggests potential therapeutic strategies for treating liver diseases related to lipid metabolism disorders by intervening in the ferroptosis process.
Показать больше [+] Меньше [-]Modeling of pulsed electric field processing
2023
Sudhir K. Sastry
Herein, we discuss the modeling of the pulsed electric field (PEF) process, with attention focused on the originally intended application of pasteurization of liquid foods. We review literature on three classes of models. First are the models for electroporation (of molecular scale), derived from physics and physical chemistry considerations, and their extension to probabilistic approaches which treat pore formation as a random process. We discuss the more recent approaches involving molecular dynamics. Then, we consider treatment-chamber and system scale models, which are based on continuum physics approaches, and rely on computational Multiphysics codes for their solution. We then discuss the base assumptions for several modeling studies. Next, we consider models for inactivation kinetics for bacteria exposed to PEF, including the first order, Hulsheger, Peleg and Weibull models. We close with discussions of other models and experimental approaches for model verification and obtaining kinetic parameters from continuous flow PEF systems.
Показать больше [+] Меньше [-]Overview of allergenic risk of novel foods
2023
Zhuo Chen | Wenfeng Liu | Jian Wang | Dongxia Yan | Hua Feng | Yong Wu | Yongning Wu | Hongbing Chen
The reported cases of food allergies are steadily increasing. With the invention of more novel foods, new and unfamiliar allergens are being introduced into our diets, which raises concerns about the potential risk of novel food allergies. The purpose of this review is to assess the allergenic risks associated with novel food components, strategies for assessing risk in relation to novel food allergens, and current regulations for managing food allergens in novel food products.
Показать больше [+] Меньше [-]Novel nanobubble technology in food science: Application and mechanism
2023
Miral Javed | Anam Matloob | Fatima-ezzahra Ettoumi | Arooj Rehman Sheikh | Ruyuan Zhang | Yanqun Xu
Nanobubble technology is one of the latest green technologies in food industry applications. Nanobubbles (NBs) are gas-filled nanoscopic bubbles with a diameter of < 500 nm. The mass production of bulk nano-bubbles raises growing interest due to their high stability, internal pressure, and an enormous surface-to-volume ratio. Also, they can increase surface area, alter the physicochemical characteristics of the medium, and facilitate mass transfer. Along with their size and stability, air, nitrogen, and carbon dioxide, NBs are widely recognized for their significance in food processing. The potential existence and ability of NBs to remain stable in liquids under ambient conditions have been a contentious issue for a long time due to the conventional thermodynamic theory. In this review, fundamental properties, and several generation methods of NBs have been described along with their mechanism. Moreover, NBs generation methods can produce fine and undeviating gas diffusion characteristics, which can be used to control the uniformity and textural qualities of various creamy and gel-based foods. Thus, we also described the possible applications of NBs along with their mechanism of action in extraction, freezing, foams, and film formation. The ability of NBs to impart health benefits makes them new, improved, and environmentally safe green techniques.
Показать больше [+] Меньше [-]Effects of heat treatment on the structure, digestive property, and absorptivity of holoferritin
2023
Ruiyang Ji | Mingyang Sun | Jiachen Zang | Chenyan Lv | Guanghua Zhao
Ferritin, as an iron storage protein, has been considered to be a well-utilized iron supplement. However, the typical thermal processing of food rich in ferritin may affect the structure and function of ferritin as an iron supplement. Here, a plant ferritin (soybean seed ferritin, SSF) and an animal ferritin (donkey spleen ferritin, DSF) were used to analyze the changes in fundamental structure and iron content after thermal treatments (68 °C for 30 min, 100 °C for 10 min). Then, SSF and DSF after thermal treatment were administered intragastrically to mice to further evaluate its digestive stability and absorptivity after thermal processing. Results showed the secondary structure, oligomeric states, iron content, and digestive stability of DSF were maintained better than that of SSF after thermal treatments, indicating that DSF has a higher thermostability than SSF. Both SSF and DSF after thermal treatment exhibited higher absorptivity than untreated ferritins. SSF showed higher absorptivity than DSF whether heated or not.
Показать больше [+] Меньше [-]Dietary phytochemicals: As a potential natural source for treatment of Alzheimer's Disease
2023
Zhuo Ren | Haixia Yang | Chenhui Zhu | Daidi Fan | Jianjun Deng
Alzheimer's disease (AD) is a common neurodegenerative disease, which seriously impairs human health and life. At present, scientists have proposed more than a dozen hypotheses about the pathogenesis of AD, including the tau propagation hypothesis. However, the exact ultimate pathogenic factor of AD remains unknown. Based on the current hypotheses, some anti-AD drugs (e.g., donepezil and Ketamine) have been developed and used in clinical treatment, which fall into two main categories, acetylcholinesterase inhibitors (AChEIs) and N-methyl-D-aspartate (NMDA) receptor antagonists, the former representative drug is donepezil, and the latter representative drug is memantine. Since these drugs have undesirable side effects, it is necessary to find safer alternatives for AD treatment. Interestingly, dietary phytochemicals have the advantages of wide source, safety, and high biological activity, which is the natural route for screening anti-AD drugs. In this study, several representatives’ dietary phytochemicals with anti-AD effect, including resveratrol, lycopene, gallic acid, berberine, ginsenoside Rg1, pseudoginsenoside-F11, ginsenoside Rh2, artemisinin, and torularhodin were selected from the published data over the last 10 years and their potential molecular mechanisms and clinical applications reviewed in the treatment of AD.
Показать больше [+] Меньше [-]A mango biological fingerprint anti-counterfeiting method based on Fuzzy C-means clustering
2023
Chaoyu Shen | Yiqin Zhang | Luyao Chen | Adele Lu Jia | Jiankang Cao | Weibo Jiang
The anti-counterfeiting of agricultural products plays an important role in protecting the rights and interests of consumers and maintaining the healthy development of the food market. Traditional anti-counterfeiting technology mainly relies on anti-counterfeiting features of packaging or labeling, which has the risk of being copied and reused. Biological fingerprint anti-counterfeiting is a method of anti-counterfeiting that takes the biological fingerprint of agricultural products as the anti-counterfeiting feature. This paper aims to take the distribution of lenticels on the surface of mango as a biological fingerprint, and propose a mango biological fingerprint anti-counterfeiting method. As the mango ripens, the peel color of mango will change significantly, which will affect the accuracy of anti-counterfeiting identification. In this paper, the images of ripe mangoes are classified by Fuzzy C-means clustering, and appropriate image enhancement technology is used to highlight the features. The results show that the mango biological fingerprint anti-counterfeiting method based on Fuzzy C-means clustering has good accuracy and robustness, and effectively reduces the impact of peel color change on anti-counterfeiting identification during mango ripening. These results support that it is feasible to use the lenticels distribution of mango as a biological fingerprint. In this paper, a computer vision anti-counterfeiting method based on lenticels distribution is proposed.
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