Volume 17, Issue 2

The purpose of the study was to reveal the differences of the flavor compounds among five Baiyunbian aged liquors by liquid-liquid extraction-gas chromatography-mass spectrometry (LLE-GC-MS) and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). In optimizing the LLE parameters, an extractant, methyl tert-butyl ether, was found which has a good extract effect and has never been used for the extraction of liquor flavor substances. Then the optimized LLE method has been applied to comprehensively analyze flavor compounds in 3-year-storage liquors (3Y), 5Y, 12Y, 15Y, and 20Y of Baiyunbian liquors combined with GC-MS. The results showed that the number and concentration of total flavor compounds also enhanced with the increase of cellaring ages. The total concentration of flavor compounds in 20Y was the highest (4543.23 mg/L), and the 3Y was the lowest (3984.96 mg/L). Among them, the significant differences among five samples were esters, alcohols, acids and nitrogen-containing compounds. Cluster analysis was used to analyze the aromas profiles by LLE-GC-MS, which revealed relationship among five samples. The results showed that the similarity of the samples was highest between 15Y and 20Y, followed by 3Y and 5Y. The characteristic flavors fingerprints of five kinds of Baiyunbian aged liquors were established by HS-GC-IMS. The results showed that the characteristic peaks in GC-IMS 3D spectra corresponding to flavor compounds can effectively characterize the sample information areas. The sectional intensities of 60 characteristic peaks in the corresponding three-dimensional spectra were selected as variables. After the principal components analysis (PCA) was used to reduce information dimensionality, it was further distinguished by HS-GC-IMS that 3Y and 5Y can be completely separated, but 15Y and 20Y were very similar and cannot be completely distinguished. The obtained results are valuable for the in-depth understanding and further study of flavors of Baiyunbian liquors.

The gas-liquid two-phase flow field inside a soybean milk machine is simulated with the Navier–Stokes equations, Renormalization group (RNG) k-ɛ turbulence model and the particle two-phase flow model. The critical speed of vortex breakdown in the container and the influence of the characteristics of the two-phase flow on the soybean crushing effect at different speeds are investigated. The results show that there is a critical value of rotating speed of 1500 rpm for the vortex breakdown in the studied machine. At this rotational speed, the turbulent eddy dissipation (TED) reaches the maximum, and the position where the vortex first rupture is near the central axis and with a distance of 0.01 m from the central axis. It is also found that with the increase of rotating speed, the pressure difference around the blade varies significantly. The research in this study has important implication for the design of the soybean milk machine.

This study explored the effects of four drying methods, namely vacuum freeze-drying (VFD), hot-air drying (HD), microwave drying (MD) and shade drying (SD) on the sensory quality, amino acids composition, phycobiliproteins structure and rehydration rate of Porphyra haitanensis . It showed that VFD dried P. haitanensis had the highest protein (35.44 ± 0.87%), polysaccharide (18.91 ± 0.64%), umami amino acids (484.67 ± 5.03 mg/100 g, dry weight) and essential amino acids (9.89 ± 0.27 g/100 g, dry weight) than another three dried products. Drying affected secondary structure of phycobiliproteins, and the phycobiliproteins from VFD laver contained the most α -helix structure and the least random coil. In addition, VFD processed laver was rich in water-soluble polysaccharides and hydrophilic amino acids, which resulted in its quick rehydration and high-water absorption capacity. The results showed that VFD was suitable for producing high-quality P. haitanensis with excellent flavor and high contents of nutritional compounds.

The effects of fermentation on the sensory qualities, lipid oxidation, harmful substances, and microbial growth of dried duck meat slice (DDMS) were investigated. The results showed that the optimal fermentation was controlled at 22.18 °C for 49.15 h with the mixed inoculation (7.09 log CFU/g) of Lactobacillus acidophilus and Pediococcus pentosaceus (2:1). Under the optimal fermentation conditions, the fermented DDMS presented higher scores of color (9.0 ± 0.16), aroma (8.8 ± 0.35), and total (8.9 ± 0.24) with lower hardness (5316 ± 98.80 g), compared to control (8.6 ± 0.21, 8.3 ± 0.26, 8.4 ± 0.08, and 7016 ± 114.17 g, respectively). Meanwhile, the histamine content decreased, and the nitrite content was reduced by nearly 60% in fermented DDMS. The lipid oxidation and microbial growth ( Escherichia coli , mold, and yeast) in DDMS were also inhibited by fermentation. It provides useful data for improving the quality and safety of meat products.

To comparatively investigate the applications potential of pectin from steeped hawthorn wine pomace (SHP), pectin-enriched yogurt was produced at set/stirred form using apple-sourced commercial pectin (CP) as control. The focus was mainly on the effect of pectins on the texture and stability of yogurt, as well as the analysis of appearance and taste, which were mainly characterized by texture analysis and sensory evaluation. Texture analysis indicated that the performance of SHP was better than that of CP, which could increase the gel rupture strength and rupture distance of set yogurt. SHP could also improve the firmness, denseness and viscosity of stirred yogurt. In other respects, SHP could also significantly increase the water holding capacity and sensory acceptance of both types of yogurt. The utilization of SHP for improving the quality of yogurt demonstrated its great potential in developing the sustainable applications of the by-product from steeped hawthorn wine.

The purpose of this study was to improve the processability of rice powder using fluidised-bed granulation technology. Bukkyungmi-rice granules were prepared by fluidised-bed granulation for 1 and 2 h using water, 5% lactose (w/v) and 5% dextrin (w/v) solutions as dispersants. The particle size of Bukkyungmi-rice granules increased from 574.83 to 728.07 μm. Granules were produced due to pore formation, and the produced particles could be dispersed easily without any entanglement. The water solubility of the produced rice granules is 1.91–6.74%, which reflects the improvement in their quality with increased treatment time. In particular, Bukkyungmi-rice granules processed in 5% dextrin showed excellent settleability. The enthalpy (Δ H ) was found to be the highest for Bukkyungmi-rice granules processed in 5% dextrin for 2 h by differential scanning calorimetry. The results indicated that rice granules obtained by fluidised-bed granulation could be used in various types of rice-based foods.

To investigate the effect of process parameters during high-moisture extrusion on system parameter (specific mechanical energy, SME) and product physical properties, blend of soy protein isolate, wheat gluten, and corn starch (50:40:10 w/w) was extruded using co-rotating twin screw extruder equipped with cooling die at 55 and 65% feed moisture, 150 and 170 °C barrel temperature, 150 and 200 rpm screw speed. The hardness and chewiness of products increased as all the extrusion process parameters became low. Among the tested range of process parameters in this study, a combination of high moisture (65%), high barrel temperature (170 °C), and low screw speed (150 rpm) generated the low SME input (less energy consumption) with high texturization degree of meat analogs. Layer and fibrous structure formation of the samples were influenced by variations in process parameters, primarily feed moisture and barrel temperature.

Propolis has known as an aromatic resin which possesses several health beneficial properties such as antimicrobial and antioxidant due to bioactive and its complex composition. Propolis has been utilized in the form of extract; however, the application in food is limited due to its insolubility in water and undesirable sensory characteristics. Encapsulation of propolis using spray drying method with addition maltodextrin with or without arabic gum could reduce the undesirable sensory characteristic, protect bioactive compounds, and increase its availability in water-soluble matrices. The total bioactive compounds were evaluated before and after the drying process in order to know the ability of matrices wall to protect it. Physical properties such as hygroscopicity and surface structure were evaluated. Maltodextrin and arabic gum ratio affect phenolic content which is in a range of 0.0425–0.0445%, and also flavonoid content in a range of 0.00273–0.00415%. The coating agent ratio also affects the hygroscopicity which is in a range of 12.01–14.06% and moisture content which is in a range of 4.65–7.71%. The SEM images show that the cracks and hollows are often on the microcapsule surface, but the particle size is more homogeneous.