Kinetics of crust formation during conventional French bread baking

Evolution of volatile compounds of baked dried tofu during catalytic infrared baking process and their correlation with relevant physicochemical properties

BACKGROUND

Energy-saving and low-carbon baking processes, as well as the need to determine the flavor-forming mechanisms of baked dried tofu, are becoming increasingly necessary. The application of emerging catalytic infrared radiation (CIR) technology in baking of dried tofu is considered of high interest due to the low energy consumption and high baking efficiency compared to traditional baking methods. Hence, this study aimed to investigate the evolution of aroma compounds in baked dried tofu during the CIR baking process and reveal relevant relationships between physical qualities, potential flavor precursors and key volatile compounds.

RESULTS

The results showed that the surface color of dried tofu gradually turned an appetizing golden yellow color during the rapid heating process, caused by the uniform infrared radiation from the radiant emitters. Meanwhile, the moisture of dried tofu experienced minimal reduction and the hardness of dried tofu gradually increased with the formation of crust on the surface. In addition, 49 volatile compounds were identified by headspace solid-phase microextraction-gas chromatography-mass spectrometry and 13 substances - 1-hexanol, 1-octen-3-ol, 1-pentanol, heptanal, nonanal, hexanal, (E,E)-2,4-decadienal, (E,Z)-2,4-decadienal, octanal, (E)-2-octenal, (E)-2-nonenal, 2-heptanone and 2-pentylfuran - were confirmed as key aroma compounds. Moreover, the amino acids aspartic acid, glutamic acid, isoleucine, lysine and arginine, and the fatty acids butyric, caprylic, capric, tridecanoic, stearic, oleic and linolenic were responsible for the unique flavor of CIR-baked dried tofu.

CONCLUSION

Consequently, the findings can provide a scientific basis for manufacturers to achieve precise quality control and large-scale production of CIR-baked dried tofu products. © 2024 Society of Chemical Industry.

Functionality of Cordia and Ziziphus Gums with Respect to the Dough Properties and Baking Performance of Stored Pan Bread and Sponge Cakes

The functionality of hydrocolloids of different origins, gum Cordia (GC), and gum ziziphus (GZ) on pan bread and sponge cake quality and their potential use in retarding the staling process have been studied. The effects of the gums were determined by assessing the pasting qualities of wheat flour slurry, dough properties, and the finished product. After 24 and 96 h of storage, investigations were conducted on the finished product. Micro-doughLab was used to assess dough mixing qualities, and a texture profile analysis (TPA) test was used to assess the texture. A hedonic sensory test of texture, scent, taste, color, and general approval was also conducted. The type of gum used had a significant impact on the physical properties of the bread and cake and their evolution through time. Reduced amylose retrogradation was demonstrated by the lower peak viscosity and substantially lower setback of wheat flour gels, which corresponded to lower gel hardness. Gums were superior at increasing the bread loaf volume, especially GZ, although gums had the opposite effect on cake volume. After both storage periods, the hardness of the bread and cake was much lower than that of the control. Except when 2% GC was used, adding GC and GZ gums to bread and cake invariably increased the overall acceptability of the product. In terms of shelf-life, GZ was able to retain all texture parameters, volume, and general acceptability close to the control after storage.

Relationship between crust characteristics and oil uptake of potato strips with hot-air pre-drying during frying process

Crust property is an important factor in affecting the oil absorption of potato strips. The present study aimed at illustrating detailed crust characteristics in relation to oil uptake of potato strips during frying as a function of hot-air pre-drying time. Results showed that oil content decreased with the increasing hot-air pre-drying time. Oil distribution determined by LF-NMR and CLSM confirmed pre-drying could reduce oil uptake of potato strips. Structural and textural analysis of crust revealed the increase in crust ratio, roughness and texture (Fm, Nwr, fwr, Wc), and decrease in crust uniformity. Results of microscopic structure unraveled that the crust of fried strips after pre-drying for 180 min became thick and compact with almost no pores. Our results suggested that hot-air pre-drying caused the formation of harder and denser crust, and oil uptake of fried potato strips after pre-drying largely depended on crust texture rather than morphology.