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•PRS3 was prepared by ultrasound-assisted autoclave gelatinization.•Under optimal treatment conditions, the PRS3 content increased from 7.5% to 15.9%.•The structure and gelatinization ...characteristics of PRS3 were studied.•The effect of PRS on the quality of steamed bread was studied.•The overall acceptance of steamed bread with 5% PRS3 was higher.
In this study, we aimed to establish an innovative and efficient preparation method of potato resistant starch (PRS). To achieve this, we prepared type 3 resistant starch (RS3) from native potato starch (PS) using an ultrasonic method combined with autoclave gelatinization and optimized by the response surface method to study the structure and properties of potato RS3 (PRS3) and its effect on the quality of steamed bread. Under optimal treatment conditions, the PRS3 content increased from 7.5% to 15.9%. Compared with PS, the B-type crystal structure of PRS3 was destroyed, and the content of hydroxyl groups was increased, but no new chemical groups were introduced. PRS3 had a rougher surface and a lower crystallinity, gelatinization temperature, viscosity, setback value, and breakdown value. The low content (5%) of PRS3 had a stable viscosity and was easily degraded by bacteria, which can improve the quality of steamed bread to a certain extent. When the PRS3 content was over 10%, it competed with the gluten protein to absorb water, which reduced the contents of β-turn and α-helix in the dough, increased the contents of β-fold, and weakened the structure of the gluten network. It also decreased the specific volume and elasticity of the steamed bread and increased the spreading rate, hardness, and chewiness. Steamed bread prepared with a flour mixture containing 5% PRS3 was similar to the presidential acceptance of control flour. In this study, a new sustainable and efficient PRS3 preparation method was established, which has certain guiding significance for the processing of Functional steamed bread with high-resistant starch.
The noble scallop Chlamys nobilis is an economically important marine bivalve cultivated in the southern sea of China since the 1980s. Unfortunately, mass mortality of this scallop species often ...occurs in summer. The present study was conducted to investigate whether the expression of heat shock protein 90 (HSP90) and level of carotenoids could enhance high-temperature stress resistance in scallop. First, the HSP90 homolog of C. nobilis (designated CnHSP90) was identified and cloned. The complete cDNA sequence of CnHSP90 was 2631 bp, including a 2181-bp open reading frame (ORF) encoding a 726 amino acid polypeptide with five HSP90 family signatures, and sharing high homology with members of the HSP90 family. CnHSP90 was ubiquitously expressed in all examined tissues including the intestine, kidney, adductor, mantle, gill, and gonad, with the highest in the gonad. Golden and brown scallops, which contain significantly different total carotenoid content (TCC), were subjected to acute thermal challenge, and the LTE₅₀ (semi-lethal temperature at 36 h heat shock) and LTI₅₀ (semi-lethal time after heat shock) as well as the correlation between CnHSP90 gene expression and TCC were determined. The LTE₅₀ of golden scallop (32.14 °C) was higher than that of brown scallops (31.19 °C), with longer LTI₅₀ at all tested temperatures, indicating that golden scallops were more resistant to thermal stress than brown scallops. Similarly, the mRNA expression levels of CnHSP90 in gill of golden scallops were significantly higher (P < 0.05) than that of brown scallops at 6, 12, 24, and 36 h, with a strong positive correlation between CnHSP90 expression level and TCC. This suggests that both carotenoids and HSP90 levels could improve thermal resistance in the noble scallops.
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•CP improve preservation effect of US in fresh-cut potatoes.•CP + US had better antimicrobial and anti-browning effects than individual treatments.•CP + US treatment maintained ...texture properties of fresh-cut potatoes.•CP + US treatment maintained membrane integrity and high antioxidant capacity.•CP + US treatment reduced the aldehyde components and maintained the flavor.
The shelf life of fresh-cut fruits and vegetables is affected by microbial growth, enzymatic browning, and loss of flavor. Although ultrasound (US) treatment is often used in the preservation of fresh-cut fruits and vegetables, it has limited antibacterial and preservative effects. Here, we used cactus polysaccharides (CP) to enhance the preservative effect of ultrasound treatment and extended the shelf life of fresh-cut potatoes. The results showed that combined treatment (CP + US) exerted better antimicrobial and anti-browning effects than individual treatments (either US or CP alone). In addition, CP + US has no adverse effect on texture and quality properties, as well as reduced the mobility of internal water. Combination treatment not only significantly decreased the activities of polyphenol oxidase and peroxidase (P < 0.05), but also maintained a high level of phenylalanine ammonia lyase activity and total phenol content during storage. It also maintained the integrity of cell membrane and reduced its permeability by inhibiting the peroxidation of membrane lipids. In addition, CP + US treatment significantly inhibited the activity of antioxidant enzymes and maintained a high DPPH scavenging ability. GC-IMS technology was used to evaluate the flavor of fresh-cut potatoes. The results showed that CP + US treatment reduced the production of a peculiar smell during storage and maintained a good flavor by inhibiting the production of aldehydes. Taken together, these results indicate that the effective preservation method of CP + US treatment can be utilized to increase the shelf life of fresh-cut potatoes.
Many marine bivalves are regarded as healthy foods due to their high carotenoid content. Only plants and microorganisms have natural carotenoids biosynthesis ability, hence, animals such as bivalves ...must obtain carotenoids from their diets. Due to the filter-feeding behavior of bivalves, they have high diversity of gut microbes. However, the relationship between gut microbes and carotenoids has not been explored in mollusks. In the present study, the interaction between gut microbes and carotenoids in two polymorphic noble scallop
, golden scallops (designated GG) and brown scallops (designated BW), were studied. The gut of GG and BW showed statistically different bacteria communities. Results from 16S rRNA gene sequencing and qPCR analysis revealed that the gut of GG had significantly higher relative abundance of carotenoids-producing bacteria
, compared with BW. Moreover, HPLC-MS analysis showed that isolate
could produce astaxanthin. The current findings are very useful as they could form the basis for future studies in determining the relationship between gut microbiota and carotenoids absorption in bivalves.
NK-lysin is a component of natural killer cells and cytotoxic T lymphocytes, and it plays an important role in the innate immune response of aquatic animals against various pathogens. In this study, ...a 640 base pair full-length cDNA sequence of the NK-lysin gene from black sea bass (Centropristis striata) (CsNKl) was obtained and analyzed. Tissue distribution results showed that CsNKl was widely distributed in various tissues of C. striata, but a significantly high expression level was detected in the spleen. CsNKl also exhibited time-dependent expression in different tissues after challenge with Vibrio harveyi. Two antimicrobial peptides (CsNKl-26 and CsNKl-28) were predicted from CsNKl proteins, and they demonstrated bactericidal functions against a variety of bacteria. Scanning electron microscopy analysis revealed that CsNKl-26 and CsNKl-28 played their bactericidal roles using the classical alpha-helix antimicrobial peptide route. These results illustrate the immune functions of CsNKl against V. harveyi, and they can be applied to developing disease control methods for fish.
Based on the field survey data of the Guangxi offshore voyage in May 2021, the distribution characteristics of the wind field during the spring monsoon transition period, the temporal and spatial ...changes in the diluted water path, and the corresponding ecological responses were analyzed. The results show the following: the core region of diluted water is located along the coast of Guangxi, and the diluted water expands to the east and west at the same time, where the thickness of the diluted water reaches 20 m. Under the combined action of the easterly wind and westward current, the westward expansion trend was stronger than the eastward expansion trend. The surface distribution of suspended solids, chlorophyll a, dissolved oxygen, and active silicon is similar to the dispersion range of the diluted water, and the high-value areas all appear near the estuary, which is basically consistent with the salinity distribution in the core region of the diluted water. Under the mixing caused by the wind and tide in the estuary area, the difference in dissolved oxygen between the surface and bottom layer is small, while in the nearshore area, the stratification of seawater hinders the dissolved oxygen’s downward transmission, resulting in a large difference in dissolved oxygen between the bottom and the surface.
Understanding the interactions between microorganisms, soil extracellular enzymes, and mangroves is crucial for conserving and restoring mangrove ecosystems. However, the unique environments ...associated with mangroves have resulted in a lack of pertinent data regarding the interactions between these components. Root, stem, leaf, and soil samples were collected at three distinct stages of mangrove succession. Stoichiometry was employed to analyze the carbon, nitrogen, and phosphorus contents of these samples and to quantify extracellular enzyme activities, microbial biomass, and various physicochemical factors in the soil. The results showed that the trends of C, N, and P in the mangrove plants were consistent. Microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial biomass phosphorus (MBP) were the highest in the Kandelia obovate community. Catalase (CAT) and β-D-G showed the highest content in K. obovate and Bruguiera gymnorrhiza, whereas cellulase showed the opposite trend. Urease was least abundant in the K. obovate community, whereas neutral protease (NPR) and acid phosphatase (ACP) were most abundant. The overall soil environment in mangroves exhibited a state of N limitation, with varying degrees of limitation observed across different succession stages. The demand for P became more intense in the later stages of succession, particularly in the K. obovate and B. gymnorrhiza communities. In conjunction with correlation analysis, it indicated that the input of mangrove plant litter had a significant regulatory influence on the C, N, and P contents in the soil. There was a significant positive correlation between MBC, MBN, and MBP, indicating synergistic effects of C, N, and P on soil microorganisms. Therefore, evaluating the nutrient ratios and sufficiency of mangroves allowed us to comprehensively understand the present environmental conditions. This study aims to develop sustainable management strategies for the conservation and restoration of mangroves.
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•There was a synergistic effect among microbial biomass carbon, nitrogen, and phosphorus.•Mangrove plant litter had a significant influence on the carbon, nitrogen, and phosphorus content in the soil.•Soil environment in mangroves exhibited a state of N limitation, with varying degrees of limitation observed across different succession stages.
An extended-release antioxidant film was prepared by starch, potato peel polyphenols (PP), and chitosan nanoparticles (CNP) to study the mechanical, hydrophobic properties and antioxidant activity of ...composite films. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to investigate the interactions and compatibility of PP, CNP-PP, and the film substrates. Scanning electron microscopy (SEM) was used to analyze the microstructures of the films. The release of PP in 10% and 50% (v/v) ethanol simulants was also examined. The results indicated that the incorporation of PP or CNP-PP into the starch film (S) increased their opacity and also improved their hydrophobicity. XRD and SEM revealed that the elongation at break increased significantly (p < 0.05), while the tensile strength decreased with the addition of CNP-PP, which were attributed to the reduced crystallinity and agglomerates distributed onto the film surface, respectively. Release studies revealed that the S + CNP-PP film exhibited an extended-release behavior of the encapsulated PP for 1440 min, compared to the burst release in the S + PP film, and the release kinetics was well fitted by the Fick’s diffusion model. Moreover, the S + CNP-PP film showed excellent antioxidant activity and could inhibit the oxidation of cheese. Therefore, the extended-release antioxidant film has potential applications in food packaging for extending food shelf-life.
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•Chitosan nanoparticles (CNP)/potato peel polyphenols (PP) extended-release antioxidant films were prepared.•CNP-PP enhanced the flexibility and hydrophobicity of composite films.•The addition of CNP decreased the release rate of PP.•The Fick diffusion model well fitted the release kinetics of PP in the 10% and 50% ethanol simulants.•The composite film exhibited excellent antioxidant activity.
Mud-blister worms are widely distributed in the ocean all over the world. It is well known that they inhabit the shell of shellfish, leading to the collapse of many shellfish farms. Although there ...are many reports of mud-blister worm incidents, many articles are not published in English, or the species of mud-blister worms have been identified wrongly, or the species names have been synchronized (merged) due to the high morphologically and genetically similar. Therefore, there is a need for a rigorous scientific review on the updated distribution, economic impact and potential treatments of mud-blister worm infestations. The development of shellfish aquaculture has led to the international transfer of shellfish form farms to farms for aquaculture purposes, in which has led to the widespread of mud-blister worms around the world's oceans. Although many treatments have been proposed, most are impractical due to the complexity of logistic, large scale or harmful to the host and environment. However, there are several approaches, including avoidance strategy, management strategy and genetic breeding strategy are potential solutions to mitigate the effects of mud-blister worm infestations in shellfish farms. This information will contribute to the development of aquaculture and fishery management plans to be implemented in shellfish aquaculture.
•Shellfish aquaculture caused widespread of mud-blister worms.•Most currently available treatments are impractical.•Avoidance, management and genetic breeding strategy are potential solutions.
•A novel carotenoid-producing bacterium was isolated from gut of a noble scallop.•The high carotenoids content was produced by the Brevundimonas scallop.•2,2′-Dihydroxy-astaxanthin has stronger ...antioxidative activity than astaxanthin.•Genomic-metabolomic approach can better characterize bacterial metabolites.
Marine bacteria produce many bioactive compounds, including carotenoids. However, the quality of bacterium carotenoids is relatively unknown. Therefore, in this study, a novel carotenoids-producing bacterium Brevundimonas scallop Zheng & Liu was isolated from Chlamys nobilis. The genome of the isolate was analyzed, carotenoid compounds were screened using HPLC-MS and the carotenoid production in B. scallop was monitored. The results revealed that the genome of B. scallop contained a carotenoid synthesis gene cluster, which involved in astaxanthin and hydroxy-astaxanthin biosynthesis. The 2,2′-dihydroxy-astaxanthin was the major carotenoid produced by B. scallop. The optimum culture condition for the highest carotenoids production (1303.62 ± 61.06 µg/g dry cells) for B. scallop was at temperature and salinity of 20 °C and 3% salt, respectively, in 10 g/L glucose as carbon source. The results showed the B. scallop is a new carotenoids resource in marine bivalve, which has an excellent antioxidative activity and potential industrial use.
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