Freeze-Thawing Treatment as a Simple Way to Tune the Gel Property and Digestibility of Minced Meat from Red Swamp Crayfish (Procambarus clarkiix).

The effects of freezing methods, including rapid freezing (RF) or slow freezing (SF), combined with thawing methods, e.g., water immersing thawing (WT) or cold thawing (CT), on the meat yield, drip loss, gel properties, and digestive properties of meat detached from red swamp crayfish were investigated. RF greatly reduced the freezing time compared to SF, and the thawing time of frozen crayfish was obviously shortened by WT in comparison to CT. RF and CT improved the meat yield but increased the drip loss, probably as a result of the greater protein denaturation or degradation. A soft and flexible gel was obtained by SF-CT, while a hard one was achieved by RF-WT. An SEM analysis showed that SF resulted in rough and irregular microstructures with larger pore sizes. Freeze-thawing led to an increase in the ß-sheet content at the expense of α-helix and variations in the microenvironment of tyrosine and tryptophan residues in protein molecules of the gels, which was more pronounced in the SF-CT group. Moreover, freeze-thawing could cause enhanced protein digestibility but reduce the antioxidant activity of gels. These findings underline the promise of the freezing-thawing treatment in tuning the gel-based meat products of crayfish.

Loss of immobilized water and intense protein aggregation responsible for quality deterioration of ready to eat firm tofu.

The influence of high-temperature treatment (100-120°C, 15 min) on the texture, color, and water-holding capacity of tofu gels was investigated. As the temperature increasing, the hardness and chewiness as well as the values of redness a and yellowness b increased gradually, while the water content and the lightness L value reduced progressively, and these variations were more pronounced at 115 or 120°C. Low field nuclear magnetic resonance showed that the loss of T22 water led to the decrease of the water content. Scanning electron microscope revealed that the micropore in gels decreased after heating, and almost entirely disappeared at 120°C. Further analysis by SDS-PAGE indicated the soy protein aggregation formed via disulfide linkage was observed in the thermal treated tofu gels, and nondisulfide linkage might also be occurred as temperature reached 110°C or higher. The quality deterioration may be attributed to immobilized water loss combined with the protein aggregation.

Quality characteristics of shucked crab meat (Eriocheir sinensis) processed by high pressure during superchilled storage.

High-pressure processing (HPP) at 300 MPa for 20 min at 25°C was used for shucking Chinese mitten crab. The shelf-life, quality as well as internal protein changes in HPP-shucked meat were investigated during superchilled storage at -4o C. Upon 3-week storage, the lightness and whiteness of HPP-shucked crab meat start to decline, while no significant changes were observed in the hardness, gumminess, and chewiness. Sensory and microbial evaluation suggested that HPP-shucked crab meat can be generally preserved in an acceptable manner within 3 weeks, although a negative influence on drip loss was found. The loss of entrapped water in crab meat as revealed by low field nuclear magnetic resonance was responsible for the relatively high thawing drip loss. The severe deterioration of meat quality and sensory occurred at 4-week storage probably as a result of exacerbated myofibrillar protein oxidation, denaturation, and crosslinking. PRACTICAL APPLICATIONS: It has been confirmed that HPP shucking can maintain the fresh-state of the crab meat and save energy compared to the conventional treatment, which could meet consumers' demand for minimally processed seafood products. In this work, the shelf-life of HPP-shucked crab meat stored at -4o C was evaluated to be 3 weeks and HPP shucking combined with superchilling can be an effective way to preserve the crab meat. These results can provide basic knowledge for the storage and distribution of HPP-shucked crab meat.

Spatiotemporal Resolved Leaf Angle Establishment Improves Rice Grain Yield via Controlling Population Density.

Leaf angle is mainly determined by the lamina joint (LJ) and contributes to ideal crop architecture for high yield. Here, we dissected five successive stages with distinct cytological features of LJs spanning organogenesis to leaf angle formation and obtained the underlying stage-specific mRNAs and small RNAs, which well explained the cytological dynamics during LJ organogenesis and leaf angle plasticity. Combining the gene coexpression correlation with high-throughput promoter analysis, we identified a set of transcription factors (TFs) determining the stage- and/or cytological structure-specific profiles. The functional studies of these TFs demonstrated that cytological dynamics determined leaf angle and that the knockout rice of these TFs with erect leaves significantly enhanced yield by maintaining the proper tiller number under dense planting. This work revealed the high-resolution mechanisms of how the cytological dynamics of LJ determined leaf erectness and served as a valuable resource to remodel rice architecture for high yield by controlling population density.

Efficiency and Safety Assurance of Six Fungicides Applied on Postharvest Cabbages Stored in a Natural Environment.

Postharvest disease is a major factor in the limited shelf life of many fruits and vegetables, and it is often managed using fungicidal spraying or soaking. In this study, we first tested the efficiency of six common fungicides on postharvest head cabbage ( Brassica oleracea var. capitata) against Botrytis cinerea. Afterward, the elimination abilities of these six fungicides on different layers of cabbage heads were examined, and the effects of the household processes on residue removal were evaluated. Results showed that very low contents of residues reached the inner layers and that peeling the three outmost leaves of cabbage could eliminate most of the investigated fungicides. All six fungicides disappeared during washing, stir-frying, or boiling, among which cyprodinil was the easiest to be eliminated. Furthermore, the combined processes reduced the residues below the limits of quantification for all six investigated fungicides, even after 2 days of spraying.