Effects of nanocellulose combined with high pressure on the textural, structural, and gel properties of Nemipterus virgatus sausage.

This study aimed to improve the gel quality of golden threadfin bream (Nemipterus virgatus) sausage by adding sugarcane nanocellulose (SNC) and using high pressure combined with a two-stage heat treatment. The gel strength, textural properties, protein secondary structure, water states, and microstructure were analyzed and compared. The results indicated that the heat treatment was beneficial to stabilizing the protein gel structure, increasing the gel strength and textural quality, and reducing the cooking loss. High-pressure treatment resulted in a decrease of α-helix and an increase of ß-sheet in the protein, forming a dense gel structure, which enhanced the gel strength and the percentage of bound water. The superior hydrophilicity of nanocellulose and its cross-linking with protein increased the percentage of bound water in the gel, which improved the water-holding capacity and mechanical properties. Therefore, the best gel quality was obtained by adding nanocellulose and treating it with high pressure combined with two-stage heating.

Effects of high-speed shear and double-enzymatic hydrolysis on the structural and physicochemical properties of rice porous starch.

This study aimed to investigate the physicochemical properties of the rice porous starch (HSS-ES) prepared by high-speed shear combined with double-enzymatic (α-amylase and glucoamylase) hydrolysis, and to reveal their mechanism. The analyses of 1H NMR and amylose content showed that high-speed shear changed the molecular structure of starch and increased the amylose content (up to 20.42 ± 0.04 %). FTIR, XRD and SAXS spectra indicated that high-speed shear did not change the starch crystal configuration but caused a decrease in short-range molecular order and relative crystallinity (24.42 ± 0.06 %), and a loose semi-crystalline lamellar, which were beneficial to the followed double-enzymatic hydrolysis. Therefore, the HSS-ES displayed a superior porous structure and larger specific surface area (2.962 ± 0.002 m2/g) compared with double-enzymatic hydrolyzed porous starch (ES), resulting in the increase of water and oil absorption from 130.79 ± 0.50 % and 109.63 ± 0.71 % to 154.79 ± 1.14 % and 138.40 ± 1.18 %, respectively. In vitro digestion analysis showed that the HSS-ES had good digestive resistance derived from the higher content of slowly digestible and resistant starch. The present study suggested that high-speed shear as an enzymatic hydrolysis pretreatment significantly enhanced the pore formation of rice starch.

Structural and rheological properties of nanocellulose with different polymorphs, nanocelluloses I and II, prepared by natural deep eutectic solvents from sugarcane bagasse.

Sugarcane bagasse, a sugar industry waste, has plentiful cellulose. The present work was aimed to prepare the quality nanocellulose with different polymorphs, nanocelluloses I (NC-I) and II (NC-II) utilizing natural deep eutectic solvents (choline chloride and oxalic acid dihydrate) combined with mechanical treatment from purified cellulose (celluloses I and II), which were prepared from sugarcane bagasse, and to further compare the structural and rheological properties of NC-I and NC-II. Results showed that the yields of NC-I and NC-II were 73.66 ± 0.11 % and 75.15 ± 0.08 %, respectively. Morphology indicated that NC-I had a needle-like appearance with a length of 769.9 ± 76.4 nm and a width of 4.9 ± 1.3, while NC-II displayed a rod-like profile with a smaller size (length: 196.3 ± 50.1 nm; width: 14.9 ± 3.8 nm). Structural characterization revealed that both NC-I and NC-II had high purity, good thermal stability (>300 °C) and high crystallinity (85.5 % and 86 %, respectively). Rheological and zeta potential properties revealed that NC-I suspension had bigger shear resistance, viscoelasticity and lower zeta potential, resulting in better storage stability compared with NC-II suspension. Therefore, the NC-I and NC-II with different characteristics may have potential applications in multiple fields, such as the food, pharmaceutical, and chemical industry.