Effects of Balsa Fish Skin Gelatin, Lentinula edodes Mushrooms, Soy Protein Isolate, and Starch on the Sensory Quality and Characterization of Physicochemical and Antioxidant Properties of New Sausage.

Sausages are loved by people for their unique texture, satisfying chewiness, and pleasant flavor. However, in the production of sausages, red meat and a large amount of fat are mainly used, and long-term consumption will increase the risk of diseases such as obesity, heart disease, hypertension, and cancer. Our previous studies have shown that the intake of red meat and fat can be reduced through the replacement of lean meat and fat in sausages by Lentinula edodes and Pleaurotus eryngii mushrooms, but this will lead to the deterioration of the gel of sausage products and seriously affect the sensory quality of sausages. In this study, the response surface method was used to optimize the amount of balsa fish skin gelatin, soy protein isolate, and starch added to, and the proportion of Lentinula edodes mushrooms replacing lean meat in, the new sausage, with Pleaurotus eryngii mushrooms replacing fat. The results show that Lentinula edodes mushrooms replaced 36.1% of the lean meat, and the addition of 0.96% balsa fish skin gelatin, 10.61% starch, and 9.94% soy protein isolate resulted in the highest sensory score and the sensory quality being the closest to that of traditional sausages. Compared with the control group, this novel sausage exhibits characteristics such as lower fat and saturated fatty acid content, reduced energy levels, and higher levels of amino acids (aspartic acid, glutamic acid, cysteine, methionine, and proline) and polyunsaturated fatty acids. The total phenolic content of the novel sausage is 12.52 times higher than that of the control. In comparison with the control group, the novel sausage demonstrates a 65.58% increase in DPPH radical scavenging activity and a 3.88-fold improvement in ABTS+ radical scavenging activity. These findings highlight the outstanding antioxidant performance of the novel sausage. This study provides new ideas for improving the sensory quality of new sausages, promoting the healthy development of the sausage industry, and promoting the high-value utilization of edible mushrooms.

Characterization of chitosan film incorporated pine bark extract and application in carp slices packaging.

Active films based on chitosan incorporated with pine bark extract (PBE) were prepared and characterized. Subsequently, these films were utilized for packaging carp slices in refrigerated storage at 4 ± 1 °C. Analysis of the physicochemical properties and biological activity of the active films revealed that, except for water content, all assessed indices showed an increasing trend with an increase in the amount of supplemental PBE. As this trend progresses, scanning electron microscopy (SEM) analysis revealed deposition on the film surface accompanied by transverse lines and fractures, while the color of the film gradually changed from light yellow to reddish-brown. Fourier transform infrared spectroscopy (FTIR) indicated that the phenolic hydroxyl groups in PBE interacted with the hydrogen in the amino groups of chitosan molecules to form non-covalent bonds. X-ray diffraction analysis (XRD) showed that the reaction between PBE and chitosan altered the crystalline structure of chitosan molecules. Moreover, the analysis of the effects of active films on the pH, water-holding capacity, thiobarbituric acid values, and the total bacterial counts of carp slices revealed that in terms of preservation, films containing 30 % PBE were the most effective, using which the shelf life of carp slices could be extended by 50 %.

Anti-Diabetic Activity of Polysaccharides from Auricularia cornea var. Li.

Auricularia cornea var. Li. polysaccharide (ACP) has many important biological activities and has potential application value in food engineering, pharmaceutical science, and health care. The results were as follows: the extraction rate of ACP was 28.18% ± 1.41% and the purity of ACP was 86.92% ± 2.80%. ACP contains mannitol 32.41%, glucuronic acid 6.96%, rhamnose 0.32%, glucose 42.35%, galactose 0.77%, xylose 16.83%, and fucose 0.36%, without galacturonic acid and arabinose. In addition, the results of an animal test of diabetes mellitus II (DM II) with ACP showed that the total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and fasting blood glucose and water in the serum of mice with ACP were significantly lower than those in the model group; the serum SOD, hepatic glycogen, and insulin of mice added with ACP were significantly higher than those in the model group. More importantly, ACP had no significant adverse effects on organ index and liver and kidney tissue morphology in mice. These results suggest that ACP can be used as a potential functional food component for the prevention or treatment of diabetes.

Effects of γ-aminobutyric acid on freshness and processing properties of eggs during storage.

Effects of γ-aminobutyric acid (GABA) on egg storage properties were investigated by comparing freshness and processing properties between eggs treated with different GABA concentrations and untreated controls. GABA treatment delayed storage-associated increases of albumen pH value and surface hydrophobicity and decreases of protein index, yolk index, Haugh unit (HU) value, albumen height, solubility, gel hardness, and apparent viscosity. Highest HU, yolk index, and emulsion stability values and peak storage performance were observed after injection of eggs with 0.05 mL of GABA (0.3 g/mL). Even after 25 days of storage, GABA-treated eggs exhibited freshness resembling that of fresh eggs, indicating that GABA treatment extended shelf life by 10 days relative to controls. Peak solubility, emulsifying activity, emulsifying stability, foaming capacity, and foaming stability values of 89.74%, 0.72, 14.18, 43.35, and 45.57, respectively, for GABA-treated eggs exceeded corresponding control group values, thus demonstrating that GABA treatment of eggs slowed storage-related deterioration of freshness and processing quality.

Physicochemical and functional properties of the muscle protein fraction of Hypomesus olidus.

The physicochemical and functional properties of myofibrillar protein (MP), sarcoplasmic protein (SP), and myostromin (MY) in Hypomesus olidus muscle were evaluated and reported in this study. These fractions are rich in Glu. Three proteins exhibited significantly different morphologies, colors, and particle sizes. The main protein bands of MP, SP, and MY are 15-220 kDa, 26-60 kDa, and 15-245 kDa, respectively. In particular, MP is more hydrophobic. Three proteins exhibited a maximum UV absorption peak at 270 nm, and all amide I secondary structures were shown to be composed of repetitive units (e.g., α-helices and ß-sheets). The three proteins demonstrated a predominantly amorphous halo, with Td values of 52.22 °C, 59.16 °C, and 58.09 °C. Regarding their properties in water/oil absorption, emulsification, and foaming, MP is the most preferred, followed by SP and MY. In conclusion, Hypomesus olidus muscle proteins are novel and potential functional nutrition ingredients for the food industry.

Study on Protein Structures of Eight Mung Bean Varieties and Freeze-Thaw Stability of Protein-Stabilized Emulsions.

In order to evaluate the freeze-thaw stability of mung bean protein isolate (MPI)-stabilized emulsions and its relationship with protein structure, proteins of eight mung bean varieties were compared. The results revealed that MPIs prepared from all eight varieties were mainly composed of five subunit bands, with albumin and globulin content ranges of 188.4-310.3 and 301.1-492.7 mg/g total protein, respectively. Protein structural analysis revealed that random coil structure (32.34-33.51%) accounted for greater than 30% of MPI secondary structure. Meanwhile, analysis of protein properties revealed emulsifying activity index (EAI), emulsifying stability index (ESI) and flexibility value ranges of 6.735-8.598 m2/g, 20.13-34.25% and 0.125-0.182, respectively. Measurements of freeze-thaw stability of MPI emulsions demonstrated that exposures of emulsions to multiple freeze-thaw cycles resulted in significantly different emulsion creaming index, oiling-off, particle size and zeta potential values for the various emulsions. Moreover, the stabilities of all eight protein emulsions decreased with each freeze-thaw cycle, as demonstrated using optical micrographs. The correlation analysis method was used to study the correlation between the original structures, emulsifying properties of proteins and the freeze-thaw stability of MPI emulsions. Correlation analysis results revealed significant relationships between albumin content, subunit bands with a molecular weight of 26.9 kDa and emulsifying properties were significantly related to the freeze-thaw stability of MPI emulsion. Thus, by determining these indicator values, we can predict the freeze-thaw stability of MPI-stabilized emulsions.

Extraction, purification, characterization, anticoagulant activity, and anticoagulant mechanism of polysaccharides from the heads of Hypomesus olidus.

The aim of this work was to extract, isolate, and purify polysaccharides from the heads of Hypomesus olidus and to evaluate their anticoagulant activities and anticoagulant mechanisms. Response surface methodology was used to optimize the extraction conditions for ultrasonic-assisted extraction of polysaccharides from the heads of Hypomesus olidus. The optimal extraction conditions consisted of ultrasonic power of 275 W, ultrasonic time of 50 min, and solid-liquid ratio of 5 ml/g, giving the yield of crude polysaccharides (GYT) of 7.73 ± 0.042%. Three polysaccharide fractions, GYT-1, GYT-2, and GYT-3 were purified from GYT by using DEAE-cellulose-52 column and Sephadex G-100 column for anticoagulant activities. The results showed that two doses (2 and 4 mg/ml) of GYT-1 and GYT-3 could significantly prolong (p < .01) in partial thromboplastin time (APTT) (2.19 and 2.37 times, 2.22 and 2.44 times, respectively) and thrombin time (TT) (2.39 and 2.46 times, 2.44 and 2.80 times, respectively) compared with normal control. In particular, GYT-3 had stronger anticoagulant activity than GYT-1, and it was composed of arabinose, fructose, glucose, and lactose with molar ratios of 0.595:1: 2.026:0.273. However, GYT-2 had no anticoagulant activity (p > .05). In addition, anticoagulation mechanism of polysaccharides from the heads of Hypomesus olidus (GYT-3) was evaluated. The results showed that the anticoagulant activity of GYT-3 was based on their binding with antithrombin AT-III. And the inhibitory effects of GYT-3 on factor IIa and Xa were related to the concentration of AT-III in plasma. This study may provide a new and promising anticoagulant drug.

Effects of Herba Lophatheri extract on the physicochemical properties and biological activities of the chitosan film.

Active films based on chitosan incorporated Herba Lophatheri extract (HLE) with different concentrations were developed. Physicochemical properties of the chitosan films incorporated HLE, including density, opacity, moisture content, color, water solubility, swelling, water vapor permeability and oil resistance were measured. Biological activities of the films include antioxidant activity and antimicrobial properties, which were characterized in terms of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and Oxford cup method, respectively. The potential interactions between chitosan and HLE in the films were investigated by Attenuated total reflectance-Fourier transform infrared analysis and X-ray diffraction. The results indicated that the moisture content, water solubility, swelling degree, water vapor permeability and oil absorption rate of chitosan/HLE films decreased up to 14.81%, 38.97%, 48.03%, 69.23% and 80% in comparison with the control chitosan film. The DPPH free radical scavenging activity of chitosan/HLE films increased by nearly 3.5 folds, and the diameter of inhibitory zone of the chitosan/HLE films extract solution against Staphylococcus aureus and Escherichia coli increased 17.02% and 19.28%, respectively. Additionally, the incorporation of HLE caused interactions between chitosan and HLE and gave rise to the chitosan/HLE films more opacity, darker, redness and yellowness appearance. In summary, the addition of HLE enhanced the moisture and oil resistance, antioxidant activity which declined with time, and antimicrobial activity of the chitosan film, which were all desirable for food packaging.

Antioxidant activity of vine tea (Ampelopsis grossedentata) extract on lipid and protein oxidation in cooked mixed pork patties during refrigerated storage.

To prevent oxidation and maintain the quality of meat products, it is essential to add antioxidants. The aim of this work was to investigate the antioxidant activity of vine tea (Ampelopsis grossedentata) extract (VTE) and evaluate the effects of VTE on the quality characteristics and lipid and protein oxidation of cooked mixed pork patties during refrigerated storage. VTE had a significant DPPH radical scavenging activity, and its IC50 was 15.35 µg/ml. VTE-treated mixed pork patties had a better texture than that of the control group (p < 0.05). VTE could significantly inhibit an increase in the TBARS value and the formation of carbonyl compounds (p < 0.05), and the inhibition was stronger than that of the butylated hydroxytoluene (BHT) group (p < 0.05), while the amount of sulfhydryl groups significantly decreased (p < 0.05). The color of VTE itself made the mixed pork patties darker (p < 0.05), but this did not affect the sensory scores and overall acceptability of the VTE-treated patties, indicating the VTE can be incorporated into mixed pork patties. The scanning electron microscopy (SEM) results showed that the VTE inhibited the oxidation of the cooked mixed pork patties during refrigerated storage. These findings may be significant to helping extend the shelf life of meat products.

Roles of Lentinula edodes as the pork lean meat replacer in production of the sausage.

The effects of substituting pork lean meat with Lentinula edodes (LE) on the physicochemical properties, amino acid content, cooking loss, texture, total phenolic content, antioxidant activity, microstructure, microbiological analysis, and sensory characteristics of sausages were evaluated. Five formulations were used in the production of sausages: the control (the pork lean meat formulation) and the four different samples in which LE substituted 25%, 50%, 75%, and 100% of pork lean meat. The results showed that LE improved the moisture, total dietary fiber, methionine, glutamic, cysteine, and total phenolic content; cooking loss; and antioxidant activity of the sausage. By contrast, LE reduced the levels of protein, ash, pH, as well as the energy level and texture of the sausage. No difference was observed between the treatments for fat content, water activity and microorganisms of sausages. In addition, LE led to slight darkening of the sausages. From the sensory point of view, all modified sausages were considered acceptable, and the pork lean meat with 25% substitution by LE exhibited best sensory characteristics. In a word, LE is a promising ingredient to partially replace the lean meat in sausages.

Characterization, hypolipidemic and antioxidant activities of degraded polysaccharides from Ganoderma lucidum.

The aim of this work is to characterize the primary structure and physicochemical properties of natural polysaccharides (GLP) and degraded polysaccharides (GLPUD) from Ganoderma lucidum, and evaluate their hypolipidemic and antioxidant activities. The results of particle size distribution and scanning electron microscopy (SEM) showed that Ganoderma lucidum polysaccharides were effectively degraded by ultrasonic method. GLPUD was composed of the same monosaccharide units as GLP but with different molar ratios. Infrared spectra and NMR showed that the primary structure of polysaccharides had not been changed by ultrasonic degradation. Meanwhile, the thermal stability of polysaccharides increased after ultrasonic treatment. After administration by GLP and GLPUD four weeks, body weight, visceral index, atherosclerosis index (AI) and biochemical indicators in serum and in liver were determined. The results showed that GLPUD had stronger hypolipidemic and antioxidant activities than GLP. GLPUD was more effective than the GLP for reducing AI, total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), raising high density lipoprotein (HDL-C) (p < 0.01), reducing malondialdehyde (MDA) content, as well as increasing the glutathione peroxidase (GSH-Px) in mice serum, increasing superoxide dismutase (SOD) activity and reducing MDA content in liver (p < 0.05 or p < 0.01). In addition, the histopathological observations of mice livers showed that GLPUD could significantly improve lipid metabolism disorder in hepatocytes. Thus, GLPUD might be tested as a more effective hypolipidemic drug.