To simultaneously address the poor stability of blueberry anthocyanins (BA) and the suboptimal processing properties of Vicia faba starch (VFS), this study proposed a synergistic strategy based on intermolecular interactions. Using BA and VFS as raw materials, a blueberry anthocyanin-Vicia faba starch complex (BA-VFS) was prepared via a gelation-freeze-drying method, and its preparation process was optimized using response surface methodology. The physicochemical and functional properties of the complex were systematically characterized by measuring its color, particle size, iodine binding capacity, texture properties, freeze-thaw stability, antioxidant activity, and in vitro simulated digestion characteristics, combined with structural analysis by Fourier transform infrared spectroscopy (FTIR). The results showed that the optimal preparation conditions for BA-VFS were a gelatinization temperature of 77 ℃, gelatinization time of 15 min, blueberry anthocyanin addition of 56% (based on dry VFS), and pH3. Under these conditions, the binding rate reached 85.12%. FTIR analysis confirmed that BA and VFS were primarily bound through hydrogen bonding and hydrophobic interactions. Compared with VFS, the complex exhibited significantly increased particle size, a color shift toward red, and a significant decrease in iodine binding capacity (P<0.05). The hardness, springiness, and freeze-thaw syneresis of BA-VFS were significantly lower than those of VFS (P<0.05). After in vitro simulated digestion, BA-VFS demonstrated significantly higher scavenging capacities against ABTS+·, DPPH·, and ·OH radicals, as well as higher anthocyanin retention, compared with free BA (P<0.05). In summary, by constructing the BA-VFS complex, this study achieved synergistic improvement in anthocyanin stability and starch processing properties. The complex integrates coloring, nutritional, and texture-modifying functions, and can serve as a novel composite ingredient for the development of functional foods.
To investigate the preservation effect of 1-methylcyclopropene (1-MCP) combined with ε-poly-L-lysine (ε-PL) on the postharvest quality of winter jujubes. 'Zhandong No.2' jujube fruits were used as raw materials. The winter jujube were treated with 1 µL/L 1-MCP alone and in combination with 0.5 g/L ε-PL, all fruits were stored at 0 ℃, and samples were taken for analysis on days 0, 22, 44, 66, and 88 of storage to study the effect on sensory quality, sugar metabolism, reactive oxygen species (ROS) and phenylpropanoid metabolism. Compared with the control group (CK), the results showed that the 1-MCP and 1-MCP+ε-PL treatments effectively delayed the progression of reddening and decay, thereby stabilising the storage quality. The 1 µL/L 1-MCP+0.5 g/L ε-PL treatment further reduced the reddening rate, and no rot was observed during storage. 1-MCP+ε-PL significantly inhibited the consumption of soluble solids content (SSC) and sucrose, inhibited the accumulation of fructose and glucose, delayed the increase of superoxide anion (O2−·), hydrogen peroxide (H2O2), and malondialdehyde (MDA), increased the activities of superoxide dismutase (SOD) and catalase (CAT), maintained the activities of phenylpropanoid metabolism-related enzymes, such as phenylalanine ammonia lyase (PAL), cinnamate 4-hydroxylase (C4H), and 4-coumarate CoA ligase (4CL), and the contents of secondary metabolites, including total phenolic, flavonoids, and lignin. The above results showed that 1-MCP combined with ε-PL effectively maintained the storage quality of winter jujube by regulating the activities of antioxidant and phenylpropanoid metabolism-related enzymes, and related metabolites.
This study systematically investigated the potential of walnut male flowers (WMF) as a functional ingredient in steamed buns by evaluating the impact of WMF incorporation at five graded levels (1%, 2%, 3%, 4%, and 5% w/w, based on flour weight) on both quality attributes and nutritional functionality. Quality parameters included specific volume, height-to-diameter ratio, instrumental color, texture profile analysis, microstructural porosity, and overall sensory acceptability. Nutritional functionality was assessed through antioxidant capacity, in vitro starch digestibility, and predicted the estimated glycemic index (eGI). Results demonstrated WMF addition significantly affected all quality indicators (P<0.05). The 2% WMF group had the highest specific volume 2.74 cm3/g and a porosity of 28.03%, whereas the 1% WMF group had the highest sensory score (80.4). With increasing WMF addition, the total polyphenol and flavonoid contents increased, reaching 4.55 and 7.5 times those of the control group, respectively. In terms of antioxidant capacity, the 5% WMF addition increased the DPPH and ABTS+ free radical scavenging rates to 3.33 and 4.36 times those of the control group, respectively, and the ferric reducing antioxidant power (FRAP) increased to 3.75 times that of the control group. Furthermore, 5% WMF addition elevated the resistant starch (RS) content to 2.28 times that of the control and reduced eGI from 75.16 to 68.18. In conclusion, moderate WMF addition improves the sensory quality of steamed bun and significantly enhances its antioxidant and slow-digestion properties, demonstrating promising potential for developing functional foods with blood glucose-lowering effects.
To address the issue of microbial contamination and spoilage in sea bass, this study selected three plant extracts—oregano, citronella, and moringa. Their chemical compositions were analyzed by GC-MS, and active components were quantified. Antibacterial activities against Escherichia coli, Staphylococcus aureus, and Shewanella putrefaciens were evaluated by measuring inhibition zone diameters, growth curves, and MIC/MBC. Crystal violet staining, electrical conductivity measurement, and scanning electron microscopy were used to reveal the underlying mechanism. GC-MS analysis showed that oregano extract mainly contained phenols and quinones, citronella extract was dominated by aldehydes and terpenes, and moringa extract was mainly composed of esters and aldehydes, with a relatively diverse composition. Determination of active components showed that the total phenolic and total flavonoid contents of oregano extract were significantly higher than those of citronella and moringa extracts (P<0.05); Moringa extract was richest in total triterpenoids (3.05 mg/g); Total polysaccharide contents of citronella and moringa extracts were higher than that of oregano extract. Antibacterial activity evaluation showed that all three extracts could disrupt cell membrane integrity, increase electrical conductivity, and inhibit biofilm formation, but their antibacterial intensities differed significantly. Oregano extract had the broadest antibacterial spectrum and the strongest activity, with inhibition zone diameters greater than 12 mm against all three strains, and it showed the most significant inhibitory effects against E. coli and S. putrefaciens. Citronella extract exhibited the strongest inhibition against S. aureus, with an inhibition zone diameter of 14.05 mm. In contrast, moringa extract showed relatively mild antibacterial activity, with inhibition zone diameters not exceeding 10 mm and biofilm clearance rates below 50%. Correlation analysis indicated that the total phenolic content was significantly positively correlated with the total flavonoid content (r=0.82, P<0.05), and the two had a synergistic enhancing effect on antibacterial activity. The total phenolic content was positively correlated with the inhibition zone diameters against E. coli (r=0.50) and S. putrefaciens (r=0.43). The total triterpenoid content was positively correlated with the inhibition zone diameter against S. aureus (r=0.29). The antibacterial activities of the three plant extracts resulted from the synergistic effects of multiple active components, and their unique chemical compositions formed the basis of these activities. This study provides a theoretical basis for the development of natural plant-derived antibacterial agents for sea bass preservation.
In order to investigate the effects of steaming on the characteristics and in vitro digestion of Polygonatum cyrtonema Hua raw materials, this study used a colorimeter and a texture analyzer to measure chromaticity values (L*, a*, b*) and texture. Combined with principal component analysis (PCA) method, the changes in Polygonatum cyrtonema Hua quality, nutritional components, and antioxidant capacity during the nine steaming and nine baking were analyzed. Using in vitro simulated digestion method, the differences in nutritional components, antioxidant capacity, and bioavailability between raw Polygonatum cyrtonema Hua and seven steaming and seven baking Polygonatum cyrtonema Hua were compared. The results showed that as the number of steaming cycles increased, the color of Polygonatum cyrtonema Hua changed significantly, with L* (brightness) and b* (yellow blue chromaticity) values continuously decreasing, a* (red green degree) value showing an initial increase followed by a decrease, and hardness and chewiness slowly decreasing. PCA results showed that color difference and texture tended to stabilize during the five steaming and five baking. The protein content continued to decrease, from 6.83% in raw Polygonatum cyrtonema Hua to 6.26% in nine steaming and nine baking. The total sugar, total phenol, and total flavonoid content all continued to increase, reaching 88.86%, 3.57%, and 3.07% respectively in seven steaming and seven baking. The in vitro antioxidant capacity continued to improve, with the strongest antioxidant capacity observed during the seven steaming and seven baking process, with an APC (Antioxidant Potency Comosite, APC) index of 95.64%. The total sugar content, total phenol content, and total flavonoid content were all positively correlated with antioxidant capacity. The simulated in vitro digestion results showed that seven steaming and seven processing Polygonatum cyrtonema Hua significantly (P<0.05) improved the antioxidant capacity and total flavonoid bioavailability during digestion, and the total sugar and total phenol content were positively correlated with antioxidant capacity. In summary, steaming can change the color and texture characteristics of Polygonatum cyrtonema Hua, and help improve the content of total sugars, total phenol, total flavonoids, and antioxidant capacity. Seven steaming and seven processing methods may be the ideal processing endpoint for Polygonatum cyrtonema Hua, and significantly (P<0.05) improve the bioavailability of total flavonoids. This study can provide scientific basis for the processing and utilization of Polygonatum cyrtonema Hua.
