Modelling the cooking doneness via integrating sensory evaluation and kinetics

Kinetics and mechanisms of thermal deterioration in silver carp (Hypophthalmichtys molitrix) surimi gel quality under high-temperature sterilization

BACKGROUND

The gelation properties of surimi gel under various high temperatures (115, 118, and 121 °C) and sterilization intensities (F0 values of 3-7 min) were systematically investigated. A kinetic model detailed quality changes during heat treatment through mathematical analysis, elucidating mechanisms for gel quality degradation.

RESULTS

Increased sterilization intensity significantly reduced the quality characteristics of surimi gel. Compared to the gel without sterilization treatment, when the sterilization intensity was increased to 7 min, the gel strength of the groups treated at 115 °C, 118 °C, and 121 °C decreased by 68.35%, 51.4%, and 51.71%, respectively, and the water-holding capacity decreased by 24.87%, 16.85%, and 22.5%, respectively. The hardness, chewiness, and whiteness of the gel also significantly decreased, and the changes in these indicators all conformed to a first-order kinetic model. Activation energy of 291.52 kJ mol-1 highlighted gel strength as the least heat-resistant. At equivalent sterilization intensities, 115 °C exhibited the poorest gel quality, followed by 121 °C, with 118 °C showing relatively better gel quality. Increased T22 and decreased PT22 suggested heightened water mobility and transition of immobilized water within the gel into free water. Protein degradation, weakened disulfide bonds and hydrophobic interaction, and protein conformation changes collectively led to a rough and incoherent gel network structure with large fissures, as verified by the results of scanning electron microscopy. Correlation analysis indicated potential for precise control over surimi gel quality by modulating physicochemical attributes.

CONCLUSION

The outcomes may be beneficial to improve the production and quality control of ready-to-eat surimi-based products. © 2024 Society of Chemical Industry.

Changes in food quality and characterization under thermal accumulation conditions during Chinese cooking

Chinese cooking is the primary treatment method for table food in China. The process is complex and large-scale, which is important to the macroeconomy and national nutrition and health. First, this article puts forward the concept of thermal accumulation for Chinese cooking by taking pork tenderloin fried at different oil temperatures, explaining changes in moisture content, hardness, and color with different thermal accumulation conditions, and measuring kinetic parameters. The variations of L* and b* obtained by the experimental results belong to the first-order reaction kinetic model, while the changes in water content and shear force belong to the zero-order reaction kinetic model. Simultaneously, the superheat value is used as a thermal accumulation indicator, combined with sensory evaluation to determine that the Z value of the human sensory overheating of pork tenderloin is 99°C, and O s,max (Z = 99°C, the reference temperature is 110°C) is 5.86 min.

Kinetic study on soybean hydration during soaking and resulting softening kinetic during cooking

This work evaluated the hydration kinetics of three yellow soybeans and one black soybean (Glycine max (Linn.) Merr.) at five temperatures (5-40°C), as well as the softening kinetics of steamed and boiled soybeans after hydration. The results showed that high temperature promoted water absorption and solids loss. Dongbei large soybean had the fastest water absorption than all others and its water diffusivities varied from 4.4×10-11 (m2 /s) to 2.6×10-10 (m2 /s) at the tested temperatures. Page model provided the best prediction of moisture content of four varieties of soybeans at five temperatures. The thermodynamic coefficient indicated that hydration is a nonspontaneous phenomenon. In addition, results showed that four soybeans exhibited no significant differences in softening rate during the cooking process, although the black soybean had the highest ultimate hardness relative to the yellow soybeans. Taken together, these new results will provide theoretical support for industrial soaking and cooking approaches for soybeans.

Effect of Thermostable α-Amylase Addition on Producing the Porous-Structured Noodles Using Extrusion Treatment

Problems with rehydration and palatability are considered as unacceptable quality characteristics for the noodles produced using high-strength extrusion technique. Thus, the aim of this study was to solve these problems by designing a novel method to create a porous structure for the high-strength extruded noodles (HENs). The quality indices of HENs were significantly improved after adding to them thermostable α-amylase (TαA) at 0.05% to 0.10%. The microstructure graphs showed that a well-developed porous structures was successfully created throughout noodle strands. This indicated that the TαA has effectively worked on starch granules in spite of the high-strength performance of the extrusion process. MALLS-GFC, X-ray diffraction, and differential scanning calorimeter investigations showed that the appearance of a porous structure was mainly attributed to the internal collapse of α-1,4-glycosidic bonds and the dissolution of water-soluble degradation products, such as dextrin and oligosaccharides. Moreover, the slight inhibited effect of excess TαA on the starch gelatinization was because of the fact that the high enzyme concentration might cause TαA to adhere or overlay on it.

PRACTICAL APPLICATION

The rehydration and palatability properties of HENs were greatly improved by creating a well-developed or honeycomb-like porous structure using TαA at low concentration. The findings of this study could be applied to enhance the quality characteristics of HENs and to encourage the research and development in the noodle industry.