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Lactic acid bacteria as starter cultures can lead to rapid acidification for gel formation in fermented fish sausages. However, there is lack of study on the volatile flavor characteristics after starter culture addition and how they affect the microbial community on the flavor formation in fish sausages. In this work, the changes of volatile compounds and microbial community in the tilapia sausage during fermentation with Pediococcus pentosaceus were respectively studied by the headspace solid-phase microextraction gas chromatography-mass spectrometry and 16S rRNA gene high-throughput sequencing. A total of 83 volatile compounds were identified, among which 32 compounds were selected as the core volatile flavor compounds. The microbial diversity in the sausage significantly decreased as the fermentation time increased. There were 12 main microbial genera in whole fermentation stages. The anaerobes such as Pediococcus, Lactococcus, Enterobacter, and Citrobacter increased obviously after fermentation, especially for Pediococcus and Lactococcus, whose total abundance reached over 95% at the end of fermentation. The correlation network model showed that Pediococcus and Lactococcus contributed most to the volatile flavor formation, followed by Enterobacter, Citrobacter, and Photobacterium. This research provides an effective method to accelerate the volatile flavor formation and inhibit the spoilage microorganisms in the fermented tilapia sausage.

This study investigated the effects of fish mince size on the gelling properties of silver carp surimi gel produced by microwave heating combined with the water bath method. As the mince size increased, the mince protein and fat contents increased, but the moisture content decreased. Although the strength and water holding capacity of the surimi gel obtained from the larger mince were lower, the detrimental effect resulting from this larger size was considerably reduced by microwave heating; this afforded the fast and selective heating of the heterogeneous surimi. A soft textured compact gel structure was obtained from the 4 mm fish mince based on the results of the texture profile analysis and scanning electron microscopy. These results are anticipated to aid in the formulation of a method for reducing the loss in the processing of muscle fibers to realize the accurate and moderate processing of low-value fish.

Dried minced pork slices (DMPS) have been widely accepted owing to their unique flavor and taste, but traditional roasting (TR) process for making DMPS are time-consuming and complicated. This study presents a microwave heating (MH) method for rapid preparation of DMPS with different fat pork levels. The results indicated that DMPS size significantly affected the MH patterns. As the fat pork content increased, the complex permittivity showed a downward tendency, and the 30% fat pork content improved both the heating rate and uniformity. Fat components significantly altered the texture and color characteristics, but DMPS made by MH possessed a higher hardness and toughness values than TR. Low-field nuclear magnetic resonance analysis demonstrated that the proportion of T21 gradually decreased in MH group, while no distinct changes were observed in the TR group with the increase of fat pork content. In addition, the results of comprehensive sensory evaluation in the MH and TR groups revealed that such a convenient MH technology is alternative for the fabrication of DMPS with acceptable product quality.

The effects of ultrasound parameters, and of the container materials used for surimi, on acoustic intensity were investigated. The frequency of ultrasound significantly affected the acoustic intensity. However, the relationship between the acoustic intensity and the frequency of the ultrasound device was not linear. The acoustic intensity increased as the height of the media increased. In addition, the acoustic intensity increased initially, but then decreased, as the volume of the media increased. Two container materials were tested: polyvinyl chloride (PVC) film and an aluminum box. The acoustic intensity was decreased significantly by the use of either material. The barrier effect of the aluminum box was weaker than that of the PVC film at lower frequencies, whereas the barrier effect of the PVC film was weaker than that of the aluminum box at higher frequencies. The gel strength of surimi increased with as the acoustic intensity increased when the latter was above a certain level. Changes in the secondary structure of myofibrillar protein were found to cause the increase in the gel strength.