Size Reduction and Calcium Release of Fish Bone Particles During Nanomilling as Affected by Bone Structure

Gelling properties of acid-induced tofu (soybean curd): Effects of acid type and nano-fish bone

The effects of different types of acid coagulants and nano fish bone (NFB) additives on the characteristics of tofu were investigated using texture analyzers, SEM, FT-IR, and other techniques. The breaking force and penetration distance, in descending order, were found in the tofu induced by glucono-d-lactone (GDL) (180.27 g and 0.75 cm), citric acid (152.90 g and 0.74 cm), lactic acid (123.33 g and 0.73 cm), and acetic acid (69.84 g and 0.58 cm), respectively. The syneresis of these tofu samples was in the reverse order (35.00, 35.66, 39.66, and 44.50%). Lightness and whiteness were not significantly different among the different samples. Regardless of the acid type, the soluble calcium content in the soybean milk was significantly increased after adding NFB. As a result, the breaking force and penetration distance of all tofu samples increased significantly, but the syneresis decreased. Compared with tofu coagulated by other acids, GDL tofu formed a more uniform and dense gel network maintained by the highest intermolecular forces (especially hydrophobic interactions). Regarding the secondary structure, the lowest percentage of α-helix (22.72%) and, correspondingly, the highest β-sheet (48.32%) and random coil (18.81%) were noticed in the GDL tofu. The effects of NFB on the tofu characteristics can be explained by the changes in the gel network, intermolecular forces, and secondary structure, which were in line with the acid type. The characteristics of acid-induced tofu can be most synergistically improved by coagulation with GDL and NFB.

Comprehensive review: by-products from surimi production and better utilization

Over 1 million MT of surimi is produced globally, which theoretically would generate approximate 2 million MT of solid by-products and more than 1 million MT of wash water. Utilization of the by-products has increasingly become interested based on their nutritional, economical, and environmental issues. Surimi by-products represent an important source of valuable compounds such as functional protein, collagen, gelatin, fish oil, peptides, minerals, and enzymes. Better utilization of the by-products would make the surimi industry sustainable and profitable. This review paper characterizes sources and composition of the solid by-products and wash water generated from the surimi production as well as factors related to extraction and processing techniques. In addition, the potential food applications are explored including specialty foods and snacks, flavor ingredients, bioactive ingredients, and functional ingredients. Moreover, an outlook summarizing the challenges and prospects on the utilization of surimi by-products is provided.

In vitro digestion and fermentation combined with microbiomics and metabolomics reveal the mechanism of superfine yak bone powder regulating lipid metabolism by altering human gut microbiota

The effects of superfine yak bone powder (YBP) on human gut microbiota (HGM) were investigated by in vitro digestion and fermentation combined with microbiomics and metabolomics. Results showed that size reduction and protein structural degradation during digestion allowed superfine YBP to release more Ca²⁺ than CaCO₃ powders with similar particle size. Moreover, the indigestible YBP further influenced HGM and was associated with increased occurrence of beneficial bacteria such as Megasphaera spp., Megamonas spp., Acidaminococcus spp., and Prevotella spp. The altered HGM was associated with greater production of short-chain fatty acids with 4-6 carbon atoms. Furthermore, the indigestible YBP was associated with up-regulation of many lipid-related metabolites, including taurine, secondary bile acids, saturated long-chain fatty acids, and ω-3/ω-6 polyunsaturated fatty acids, which modulated favorably lipid metabolic pathways. These findings implied the potential activity of superfine YBP as a food fortifier in favorably altering HGM community structure and regulating lipid metabolism.

Physicochemical property, volatile flavor quality, and microbial community composition of Jinhua fatty ham and lean ham: A comparative study

The physicochemical property, volatile flavor compounds, and microbial community structure of Jinhua fatty ham (FH) and lean ham (LH) were investigated and compared by high-throughput sequencing and HS-GC-IMS. Results showed that FH had higher pH and slightly lighter and yellower color than LH. Meanwhile, 33 volatile flavor compounds were identified from FH and LH, among which LH showed higher abundance of total alcohols and acids, but FH had generally richer aldehydes, ketones, esters, heterocyclic, and sulfur-containing compounds. Moreover, FH and LH did not have significant difference in α-diversity of bacterial community, but LH presented a much lower α-diversity of fungal community than FH. Besides, the dominant microorganisms (relative abundance >2%) in FH were Ruminococcaceae UCG-005, Staphylococcus, Ruminococcaceae UCG-014, Meyerozyma, and Aspergillus at the genus level, while in LH were Staphylococcus, Psychrobacter, Halomonas, Propionicicella, Ruminococcaceae UCG-005, Meyerozyma, Yamadazyma, and Aspergillus. Furthermore, the analysis of Pearson's correlation and metabolic network confirmed that the discriminative flavor compounds of FH were mainly β-oxidation and degradation products of fatty acids, while those of LH were mostly derived from the Strecker reaction or microbial metabolism of amino acids. The present study could help understand the potential pathway of characteristic microorganisms affecting flavor formation of fat-deficient dry-cured hams and provide theoretical supports for developing healthier fermented meat products.

Effects of micro-/nano-scaled chicken bones on heat-induced gel properties of low-salt pork batter: Physicochemical characteristics, water distribution, texture, and microstructure

The effect and mechanism of micro-/nano-scaled (MCB/NCB) chicken bones on improved gel properties of low-salt (0.5%) pork batters (LSPB) were investigated. Results showed that the Ca²⁺ released from MCB/NCB induced protein conformational transition of LSPB from α-helix and β-turn to random coil, which facilitated the orderly protein aggregation, resulting in the formation of denser and more uniform gel network. The better-organized gel network not only improved the textural properties and gel strength, but also contributed to the cooking loss reduction, water release decline, water state transition from free water into more immobilized water, and proton density increase, resulting in better sensory attributes. NCB showed more preferable effects on the property improvement of LSPB gels than MCB, because of its smaller particle size, less redness and yellowness, higher dispersibility, and higher Ca²⁺ release. This study could help promote the high-value utilization of poultry by-product bones and development of low-salt meat products.

Ultrasound-assisted solubilization of calcium from micrometer-scale ground fish bone particles

In order to promote the extraction of biological calcium from fish bone, ultrasonication was used to process micrometer-scale fish bone particles (MFPs) and investigate the mechanism of action in relation to bone structure. With ultrasonication treatment (300 W, 60°C, 2 h), the content of calcium release increased by 25.6%. Calcium release reached 94.0% of total calcium after 24-h treatment. The surface of the MFPs was significantly damaged by ultrasound-induced cavitation, resulting in holes and separation of the layered structure. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) analysis demonstrated that the crystalline structure of hydroxyapatite was disrupted, the triple helical structure of mineralized collagen fibrils (MCFs) was loosened, and hydrogen bonding in collagen decreased, facilitating the release of hydroxyapatite crystals. Thus, ultrasonication may be a practical alternative to nanomilling for industrial processing of waste fish bones to produce soluble calcium as an ingredient in calcium supplements and supplemented foods.

Microencapsulation of immunoglobulin Y: optimization with response surface morphology and controlled release during simulated gastrointestinal digestion

Immunoglobulin Y (IgY) is an effective orally administered antibody used to protect against various intestinal pathogens, but which cannot tolerate the acidic gastric environment. In this study, IgY was microencapsulated by alginate (ALG) and coated with chitooligosaccharide (COS). A response surface methodology was used to optimize the formulation, and a simulated gastrointestinal (GI) digestion (SGID) system to evaluate the controlled release of microencapsulated IgY. The microcapsule formulation was optimized as an ALG concentration of 1.56% (15.6 g/L), COS level of 0.61% (6.1 g/L), and IgY/ALG ratio of 62.44% (mass ratio). The microcapsules prepared following this formulation had an encapsulation efficiency of 65.19%, a loading capacity of 33.75%, and an average particle size of 588.75 μm. Under this optimum formulation, the coating of COS provided a less porous and more continuous microstructure by filling the cracks on the surface, and thus the GI release rate of encapsulated IgY was significantly reduced. The release of encapsulated IgY during simulated gastric and intestinal digestion well fitted the zero-order and first-order kinetics functions, respectively. The microcapsule also allowed the IgY to retain 84.37% immune-activity after 4 h simulated GI digestion, significantly higher than that for unprotected IgY (5.33%). This approach could provide an efficient way to preserve IgY and improve its performance in the GI tract.

Asian carp: A threat to American lakes, a feast on Chinese tables

Asian carp, which are widely distributed in Asia and Europe, are nutritious and popular with consumers. In China, Asian carp is a tasty dish and has been consumed for thousands of years. However, they are considered aggressive invasive species that threaten rivers, lakes, and indigenous species in the United States. Asian carp have proliferated greatly in the water basin of the Mississippi River and its tributaries, and they have caused severe ecological problems over the past 20 years. In recent years, several state governments along the Mississippi River have implemented assistance programs to eliminate invasive Asian carp, but these did not alleviate the threat. We conducted a survey to understand consumers' attitudes toward Asian carp in the United States, and related reports were reviewed to explore the possibility of Asian carp as food fish on American tables. Emphasis is placed on the farming history, functional characteristics, consumption preferences, and successful utilization methods for Asian carp in China. In addition, suggestions and possible utilization methods were proposed to improve the negative impression of Asian carp in the United States. Further research is needed to take full advantage of this huge excellent source of food or health supplements. This review provides ideas and directions for the use of Asian carp in the United States. We believe that through effective cooperation between China and the United States, the negative aspects of Asian carp in the United States could be diminished, and a mutually beneficial situation could be achieved.

Effects of nano fish bone on gelling properties of tofu gel coagulated by citric acid

Tofu gel was made by using citric acid (0.14%) in combination with varied volumetric ratios (e.g., 0-4%) of nano fish bone (NFB). The gel properties were investigated by colorimetry, penetration tests, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. As the volumetric ratio increased from 0 to 3%, the soluble calcium concentrations of soymilk linearly increased from 1.78 to 6.42 mg/mL. Correspondently, yield, moisture and texture values of the tofu gel increased continuously (p < 0.05) while syneresis and whiteness decreased (p < 0.05). Furthermore, ionic bonds, hydrophobic interactions and hydrogen bonds increased by 140%, 40% and 10%, respectively. With the addition of NFB, the α-helices of the soybean proteins changed to β-sheets and random coil structures. Additionally, the tofu gel network became more orderly and denser. The results confirmed that NFB can be utilized as a functional coagulant ingredient to improve the properties of acid-induced tofu gels.

Identification and characterization of novel antioxidant peptides from crucian carp (Carassius auratus) cooking juice released in simulated gastrointestinal digestion by UPLC-MS/MS and in silico analysis

The objective of this work was to separate, identify and assess antioxidant peptides from the simulated gastrointestinal (GI) digestion of crucian carp (Carassius auratus) cooking juice (CCCJ), which has been previously found with this activity. The CCCJ after simulated GI digestion treatment was separated gradually by ultrafiltration and RP-HPLC. Five novel antioxidant peptides with 10-13 amino acid residues were identified by UPLC-MS/MS. Their in silico assessments showed amphiphilic nature, good sensory quality and different target sites in the human body. Meanwhile, their three-dimensional structure predictions exhibited at least one β-turn, β-sheet and/or α-helix with partial hydrophobic and/or net-charged residues exposed to the external medium, which was good evidence for high antioxidant activity. Ultimately, four novel peptides with high antioxidant activity were found, among which IREADIDGDGQVN (1401 Da), PEILPDGDHD (1107 Da) and ASDEQDSVRL (1119 Da) exerted the highest DPPH radical scavenging activity with IC₅₀ of 1.78, 1.18 and 1.45 mM, respectively, while APLEEPSSPH (1063 Da) showed the highest Fe²⁺ chelating ability with IC₅₀ of 0.09 mM. This work could help understand the mechanism of CCCJ on human health promotion and improve the economic value of the crucian carp processing industry.