Soybean residue is an underutilized, nutrient‐rich by‐product of soybean processing. To enhance its value, we subjected soybean residue to superfine grinding and measured the resulting physiochemical properties and antioxidant activities. We prepared powders with particle sizes of 115.35, 77.93, 39.38, 25.01, and 20.44 μm. As particle size decreased, the surface area (from 96.46 to 198.32 m2/kg) and swelling capacity (from 2.05 to 10.62 ml/g) increased. Conversely, we observed decreases in the surface‐number mean (from 23.07 to 11.20 μm), volume‐surface mean (from 141.70 to 27.96 μm), angles of repose (from 48.30° to 31.46°), water holding capacity (from 7.86 to 4.39 g/g), and oil binding capacity (from 1.78 to 1.42 g/g). The water solubility index and antioxidant activity (reducing power and free radical scavenging activities of 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azino‐di‐(3‐ethylbenzthiazoline sulfonic acid)) improved as particle size decreased. In conclusion, superfine grinding improved some properties of soybean residue. Additionally, our findings provide theoretical support for using superfine grinding in industrial food applications.
Salmonella , a bacterial, food-borne pathogen, can contaminate meat, milk, and vegetables. While appropriate measures are available to control Salmonella , the inhibitory phytochemicals from plants are gaining increased attention. Punicalagin, a natural antibiotic, is one of the main active tannins isolated from Punica granatum L . To obtain a broader understanding of the effect of punicalagin on the cell membranes of Salmonella typhimurium , the killing kinetics, extracellular potassium concentration, release of cell constituents, intracellular pH (pH in ), membrane potential, and morphological features were characterized to elucidate the mechanisms of action. Treatment with punicalagin induced an increase in the extracellular concentrations of potassium and a release of cell constituents. A higher pH gradient, an increase in the pH in and cell membrane depolarization were observed after punicalagin treatment. Electron microscopy observations showed that the cell membrane structures of S. typhimurium were damaged by punicalagin. It is concluded that punicalagin inhibits the proliferation of S. typhimurium and destroys the integrity of the cell membrane, leading to a loss of cell homeostasis. These findings indicate that punicalagin has the potential to be used as a food preservative in order to control S. typhimurium contamination in food and reduce the risk of salmonellosis.
Sweet potato leaves (SPLs) containing abundant functional components are consumed primarily as fresh vegetables worldwide. This study investigated the physical properties of superfine grinding SPLs powder, and their effects on cooking, texture, and sensory properties, micro-and molecular structures of starch noodles were also explored. The results showed that the bulk and tapped density (from 0.34 to 0.28 g/ mL(3) and from 0.69 to 0.61 g/mL(3)), repose and slid angle (from 42.15 to 30.96 degrees and from 48.67 to 22.00 degrees), water-holding capacity and swelling capacity (from 8.66 to 4.94 g/g and from 10.03 to 7.77 mL/g) of SPLs powders were decreased with milling time increased. The cooking loss, swelling index, texture, and sensory properties of SPLs sweet potato starch noodles (SPLSNs) were improved as the particle size of SPLs decreased. XRD and FT-IR showed that SPLSNs contained less complete crystallites (from 28.85% to 14.19%) and lower proportion of crystalline region (R-1047/1017 from 0.96 to 0.81, R-1017/ 994 from 0.41 to 0.43). SEM revealed that SPLSNs exhibited fewer ordered arrays and smooth cross sections. Our findings provide a foundation for utilizing SPLs and developing functional starch noodles.
Moderate non‐covalent interaction of protein and polyphenols can improve the emulsifying property of protein itself. The corn protein hydrolysate (CPH) and tannic acid (TA) complex was successfully used to construct nanoemulsion for algal oil delivery. There has been no study on the feasibility of this nanoemulsion delivery system for other food functional components, for example, β‐carotene (β‐CE). CPH/TA complex‐based nanoemulsion system for β‐CE delivery was studied, focusing on the effect of β‐CE content on the physicochemical stability of the nanoemulsions. The nanoemulsion delivery systems (dia. 150 nm) with low viscosity and good liquidity were easily fabricated by two‐step emulsification. The nanoemulsions with high β‐CE content (>71.5 μg/mL) significantly increased (p < .05) the emulsion droplet size. However, there was no significant (p > .05) effect of β‐CE content on polydispersity index (PDI) and zeta potential of the nanoemulsions. The storage (30 days) experiment results demonstrated that the droplet size of the nanoemulsions with varying β‐CE content increased slightly during storage. However, the PDI values showed a slightly decreasing trend. Zeta potentials of the nanoemulsions showed no noticeable change during storage. Moreover, after storage of 30 days, the retention ratios of β‐CE were found to be up to 90%, which suggests an excellent protective effect for β‐CE by the nanoemulsion systems. The CPH/TA complex stabilized nanoemulsions could aggregate in gastric condition, but the β‐CE content did not have obvious effect on the digestive stability of the nanoemulsions. The CPH/TA complex could be employed as an emulsifier to construct a physicochemical stable nanoemulsion delivery system for lipophilic active components.