W/O/W emulsions can be used to encapsulate both hydrophobic and hydrophilic bioactive as nutritional products. However, studies on protein stabilized gel-like W/O/W emulsions have rarely been reported, compared to the liquid state multiple emulsions. The purpose of this study was to investigate the effect of different oil–water ratios on the stability of W/O/W emulgels fabricated with salt-soluble proteins (SSPs) of Sipunculus nudus. The physical stability, structural characteristics, rheological properties, and encapsulation stability of vitamin C and β-carotene of double emulgels were investigated. The addition of W/O primary emulsion was determined to be 10% after the characterization of the morphology of double emulsion. The results of microstructure and rheological properties showed that the stability of W/O/W emulgels increased with the increasing concentration of SSPs. Additionally, the encapsulation efficiency of vitamin C and β-carotene were more than 87%, and 99%, respectively, and still could maintain around 50% retention of the antioxidant capacity after storage for 28 days at 4 °C. The aforementioned findings demonstrate that stable W/O/W emulgels are a viable option for active ingredients with an improvement in shelf stability and protection of functional activity.

In order to study the effects and mechanism of Monascus on the quality of hairtail surimi, high-throughput sequencing technology, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS), and electronic nose techniques were used to investigate the changes in the quality, microbial diversity, and volatile flavor compounds of Monascus-fermented hairtail surimi (MFHS) during fermentation. The results showed that the total volatile basic nitrogen (TVB-N) index of hairtail surimi fermented by Monascus for 0–5 h met the requirements of the national standard. Among them, the 1 h group showed the best gel quality, which detected a total of 138 volatile substances, including 20 alcohols, 7 aldehydes, 12 olefins, 4 phenols, 12 alkanes, 8 ketones, 15 esters, 6 acids, 16 benzenes, 4 ethers, and 8 amines, as well as 26 other compounds. In addition, the dominant fungal microorganisms in the fermentation process of MFHS were identified, and a Spearman correlation analysis showed that 16 fungal microorganisms were significantly correlated with the decrease in fishy odor substances in the fermented fish and that 8 fungal microorganisms were significantly correlated with the increase in aromatic substances after fermentation. In short, Monascus fermentation can eliminate and reduce the fishy odor substances in hairtail fish, increase and improve the aromatic flavor, and improve the quality of hairtail surimi gel. These findings are helpful for revealing the mechanism of the quality formation of fermented surimi and provide guidance for the screening of starter culture in the future.

In this study, complexes of pregelatinized Chinese yam starch with ferulic acid (PCYS+FA) were prepared using a boiling water bath, with varying levels of Chinese yam starch (CYS) and ferulic acid (FA). The investigation focused on the effects of FA addition (3%, 9%, and 15%) on the physicochemical properties and structure of PCYS+FA complexes. The solubility, swelling, and water-holding capacity of PCYS+FA were compared with those of CYS, with the solubility and swelling showing a gradual enhancement with increasing FA content. The incorporation of FA reduced the thermal stability of CYS, decreasing the initial degradation temperature from 245.94 °C (CYS) to 228.17 °C (PCYS+15%FA). Infrared spectroscopy revealed that CYS and FA were bound through non-covalent intramolecular hydrogen bonding. Furthermore, X-ray diffractograms showed that FA and CYS formed a V-type complex, in which the crystallinity of PCYS reached a minimum of 3.72%, and the degree of molecular ordering was reduced. Scanning electron microscopy analysis demonstrated that FA adhered to the surface of starch granules, resulting in the formation of pores that facilitated the entry of FA molecules into the internal crystal region of starch, allowing them to interact with starch molecules.

Chlorogenic acid (CA) has received extensive attention in the field of improving the properties of starch. At present, few studies have focused on the influences of chlorogenic acid (CA) addition levels on the physicochemical properties of Chinese yam (Dioscorea opposita Thunb.) starch (CYS). Therefore, the effects of varying chlorogenic acid (CA) concentrations (3%, 5%, and 7%) on the structural characteristics, in vitro digestibility, and rheological properties of Chinese yam starch (CYS) and its CA-incorporated complexes was investigated. The incorporation of CA disrupted the double-helix structure of starch, while promoting the formation of double- and single-helical structures in amylose, as revealed by Fourier-transform infrared spectroscopy and Raman spectroscopy, respectively. This led to decreased crystallinity and the formation of a V-type crystalline structure. The interactions between CA and CYS molecules facilitated the construction of a more compact network architecture within starch granules, thereby decreasing its in vitro digestibility and significantly increasing resistant starch content. Moreover, CA enhanced the short-range ordered structure of starch, restricted granule swelling, strengthened shear-thinning behavior, and reduced gel strength and viscosity. In summary, the complexation between Chinese yam starch and chlorogenic acid provides a promising strategy to tailor the rheological properties and in vitro digestibility of starch, providing a promising candidate substrate for fabricating low-digestibility starchy functional food formulations.