Search

The weak gelling and poor digestion properties of myofibrillar protein (MP) under low-salt conditions constrain the development of functional sodium-reduced meat products. This study investigated how modification with γ-polyglutamic acid (γ-PGA) and transglutaminase (TG) cross-linking influences the conformation, gelation, and in vitro digestion of low-salt MPs pretreated with konjac glucomannan (KGM) and ultrasound. The results revealed that γ-PGA addition effectively facilitated the exposure of tryptophan and tyrosine residues in low salt MPs. The better dispersibility and slightly lower rheological properties of protein sols suggested the circumscribed effect of γ-PGA in augmenting protein gelation. TG crosslinking promoted moderate aggregation of MPs through different sites in myosin fragments, augmented the uniform distribution of sodium, and remarkably enhanced the gelling behavior of MPs. Importantly, the simultaneous incorporation of γ-PGA contributed to the refinement and uniformization of the TG cross-linked protein gel network, especially in the protein gel modified by pre-ultrasound treatment in combination with KGM. This result could also be corroborated by the augmented intermolecular interactions and enhanced digestibility observed in γ-PGA-modified TG crosslinked protein gel. Coupled with the identification of potentially bioactive peptides, it was confirmed that myosin light chain, actin, and myomesin account for the major contribution to the γ-PGA-induced changes in MP gels. Therefore, TG cross-linking combined with γ-PGA could be used to regulate the conformation and gelling properties of low-salt MPs, thus influencing the sodium distribution and digestion properties of low-salt meat products. [Display omitted] • The moisture loss defect in the TG cross-linked MP gel was compensated by γ-PGA. • The protein aggregation and uniform distribution of sodium were improved by TG. • The association of γ-PGA facilitated the refinement of TG cross-linked MP gels. • γ-PGA promoted neck TG cross-linking in MPs modified by pre-ultrasound with KGM. • Myosin light chain, actin, and myomesin caused changes in γ-PGA-modified MP gels. [ABSTRACT FROM AUTHOR]

Cultured meat, an emerging meat production technology, has reduced environmental burden as well as provide healthier and more sustainable method of meat culture. Fat in cultured meat is essential for enhancing texture, taste, and tenderness. However, current cultured meat production method is limited to single-cell type. To meet the consumer demands for cultured meat products, it is crucial to develop new methods for producing cultured meat products that contain both muscle and fat. In this study, cell viability and differentiation were promoted by controlling the ratio and cultivation conditions of myocytes and adipocytes. The total digestibility of cultured meat exceeded 37%, higher than that of beef (34.7%). Additionally, the texture, appearance, and taste of the co-cultured meat were improved. Collectively, this research has great promise for preparing rich-nutritious and digestion cultured meat. [Display omitted] • Co-culture enhanced meat quality by controlling the ratio of bovine myocytes and adipocytes. • Co-cultured meat improved the texture, appearance, flavor, digestibility, and basic nutritional components. • Co-cultured meat increases consumer acceptance and meets the diversity of consumer needs. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a disease characterized by degeneration of the joint complex due to cartilage destruction. Fraxetin, a widely used and studied coumarin compound extracted from a traditional Chinese herb (Qin Pi), has shown anti-inflammatory and antioxidant properties, but its effects on OA have not been studied. In the present study, western blotting, immunofluorescence, and terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) were used to evaluate the effects of fraxetin on IL-1β-induced apoptotic activity, inflammatory responses, and catabolism in rat chondrocytes. The results showed that fraxetin prevented IL-1β-induced apoptosis of chondrocytes and inhibited inflammatory mediator release by regulating the Toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor (NF)-κB pathway in chondrocytes. Additionally, fraxetin suppressed the upregulation of matrix metalloproteinase 13 (MMP13) and degradation of collagen II in the extracellular matrix (ECM). Moreover, the effects of fraxetin in vivo were assessed in a monosodium iodoacetate (MIA)-induced rat model of OA using hematoxylin and eosin (H&E) and Safranin O-fast green staining and magnetic resonance imaging (MRI). The results showed that fraxetin protected the cartilage against destruction. In conclusion, fraxetin could be a potential therapeutic for OA. [ABSTRACT FROM AUTHOR]

[Display omitted] • Gelatin-film loaded with alizarin and essential oil Pickering emulsion was prepared. • The films were ammonia-responsive with antibacterial and antioxidant activity. • The freshness could be quantified via an RGB-detecting smartphone application. • The film had the potential used as a smart label for beef quality judgment. • This work expanded the multifunctional film in the food packaging filed. In this study, a novel multifunctional food packaging was developed by incorporating alizarin (AL) and oregano essential oil Pickering emulsion (OEOP) into a gelatin film matrix. The incorporation of OEOP and alizarin improved the UV–vis resistance property of the film, blocking almost all UV–vis light (decreasing 71.80% to 0.06% at 400 nm). The elongation-at-break (EBA) was 4.02 times of that of gelatin film, indicating the improved mechanical properties of the films. This film showed a significant color change from yellow to purple in the pH range of 3–11 and a considerable sensitivity to ammonia vapor within 4 min, which was attributed to the deprotonation of the alizarin molecule. The film's antioxidant and dynamic antimicrobial capacity was significantly improved owing to the sustained release effect of OEOP. Furthermore, the multifunctional film effectively slowed down the beef spoilage rate and provided real-time visual monitoring of freshness through color changes. Additionally, the color change of the beef quality was linked to the RGB values of the film through a smartphone APP. Overall, this work broadens the possibilities of applications in the food packaging industry for multifunctional food packaging film with preservation and monitoring functions. [ABSTRACT FROM AUTHOR]

A double-layer film was developed with tannic acid (TA) co-pigmented purple potato anthocyanin extract (PAE)-agar as the inner layer, and K-carrageenan-oregano essential oil Pickering emulsion (OPE)/silver nanoparticles (TA-AgNPs) as the outer layer. Molecular docking and FT-IR results elucidated that intermolecular hydrogen bond was the main interaction between components in the agar-carrageenan matrix, with TA and PAE contributing to intensified anthocyanin color through π-π stacking. The incorporation of OPE/TA-AgNPs enhanced the film's hydrophobicity (WCA > 100°) and UV–vis barrier (close to 0% at 200-320 nm, effectively impeding UVA, UVB, and UVC) properties and exhibited outstanding antioxidant (DPPH scavenging rate > 88%) and antimicrobial activities. This film showed a significant color change in the pH range of 2–12 (from pink to yellow) and a considerable sensitivity to volatile amines within 2 min. The films effectively alleviated beef spoilage (extending the shelf life of beef for 1d) and reflected the freshness of beef during storage. Additionally, the digital color information of the film was obtained by a smartphone combined with RGB values analysis to quantify the freshness of beef rapidly. Therefore, this study expands the application of food packaging films with freshness preservation and monitoring in the field of animal-derived food. [Display omitted] • A multifunctional bi-layer polysaccharide-based film was constructed. • TA-crosslinked-gelatin nanoparticles were used as a Pickering emulsions stabilizer. • The color intensity of anthocyanins was enhanced by TA co-pigmentation. • The film alleviated beef spoilage by good antibacterial and antioxidant activity. • Freshness could be quantified with the smartphone-assisted RGB App. [ABSTRACT FROM AUTHOR]

A highly stable "tannin-anthocyanin conjugated" trifunctional active intelligent film was developed by incorporating bilberry anthocyanins (BA) as an indicator and tannin acids (TA) as a co -pigment into a sodium alginate-carrageenan polysaccharide matrix (SC-BA/TA). The doping of TA conferred outstanding antioxidant (DPPH scavenging rate > 90%) and antibacterial properties to the film, particularly effective against S. aureus. The SC-BA/TA films effectively blocked UV rays (close to 0%, effectively impeding most UVA, as well as nearly all UVC and UVB) within the range of 200–320 nm. The TA-BA co-pigment effect significantly improved the anthocyanins' storage and color stability (retention rate > 70% under UV and natural light conditions). TA forms conjugate with anthocyanins by π-π stacking and hydrogen bonding interactions with co-pigmentation rate increases of 10.5% and 11.0% for pH 2 and pH 3, respectively. The film exhibited good responsiveness to volatile amines within 4 min, and offered real-time monitoring of beef freshness, as indicated by visualizing color changes (from red to dark yellow color). Furthermore, the integration of the film's RGB value with beef quality via a smartphone App effectively reduces the variability in visual recognition among individuals. To sum up, composite films based on the "tannin-anthocyanin conjugate" approach hold great potential in the field of food freshness monitoring, opening new possibilities for the development of highly stable active smart packaging films. [Display omitted] • The active smart polysaccharide film was fabricated with TA and anthocyanins. • The conjugate was formed between TA and anthocyanins via π-π stacking. • The co-pigmentation of TA and anthocyanins improves the anthocyanins' stability. • The freshness could be quantified via RGB values offered by the smartphone App. • This work provides new insight into the highly stable active smart food packaging. [ABSTRACT FROM AUTHOR]

A novel volatile amine-responsive food freshness smart film, CG-BAE, has been developed utilizing chitosan (CS) and gelatin (GL) as film substrates and butterfly pea flower anthocyanin extract (BAE) as the indicator. The pH value of the film-forming solution was found to significantly impact the physical properties, biogenic amine response sensitivity, and initial color of the film. The hydrogen bonding interaction between anthocyanins and the film matrix was identified as the main binding force, as confirmed by FT-IR spectroscopy and molecular docking simulation analysis. Notably, CG-BAE-2.0 films have demonstrated excellent color stability, antioxidant activity, and color responsiveness. The performance of the film in monitoring beef freshness was evaluated and proved clear differentiation between four stages: freshness, sub-freshness, onset of spoilage, and complete spoilage. The color change of the film was assessed using RGB values obtained from a smartphone App, reducing the difference in color recognition by individual naked eyes. Therefore, this work addresses the limitation that BAE-based intelligent films cannot be distinguished at the starting point of meat spoilage, and presents a promising approach to sub-freshness indication, opening new possibilities for food freshness differentiation monitoring. [Display omitted] • The indiscernible colorimetric food decay initial point of BAE-based film was solved. • The film's initial color affected the accuracy and sensitivity of the result. • The pH-regulated film was responsive to volatile amines. • The freshness could be quantified using RGB values given by the smartphone App. • This work broadened the application of food sub-freshness indicator film. [ABSTRACT FROM AUTHOR]

If a honey bee ( Apis spp.) colony becomes queenless, about 1/3 of young workers activate their ovaries and produce haploid male-producing eggs. In doing so queenless workers maximize their inclusive fitness because the normal option of vicarious production of relatives via their queen’s eggs is no longer available. But if many workers are engaged in reproduction, how does a queenless colony continue to feed its brood and forage? Here we show that in the Asian hive bee Apis cerana hypopharyngeal gland (HPG) size is larger in queenless workers than in queenright workers and that bees undertaking brood-rearing tasks have larger HPG than same-aged bees that are foraging. In queenless colonies, workers with a smaller number of ovarioles are more likely to have activated ovaries. This reinforces the puzzling observation that a large number of ovarioles reduces reproductive success in queenless A. cerana . It further suggests that reproductive workers either avoid foraging or transition to foraging later in life than non-reproductive workers. Finally, our study also showed that ovary activation and larger-than-average numbers of ovarioles had no statistically detectable influence on foraging specialization for pollen or nectar. [ABSTRACT FROM AUTHOR]