Search

The aim of this study was to evaluate volatile compounds of dried fish floss with different sugar using electronic nose (e‐nose) and headspace‐solid‐phase microextraction/gas chromatography‐mass spectrometry (HS‐SPME/GC‐MS). Maillard reaction (MR) was carried out by reducing sugar (glucose, xylose, fructose, and galactose) instead of sucrose to increase the flavor of fish floss. The results showed that 64 volatile compounds were detected in fish floss. Hexanal, heptanal, nonanal, decanal, undecanal, tridecanal, pentadecanal, 4‐ethyl‐benzaldehyde, dodecanal, benzene acetaltaldehyde, (E, E)‐2,6‐nonadienal, (E, E)‐2,4‐decadienal, 2‐undecanone, 1‐octen‐3‐ol, (E)‐2‐hepten‐1‐ol, 1‐heptanol, and 2‐pentyl‐furan were regarded as key volatile compounds. Furthermore, e‐nose and partial least squares‐discriminant analysis (PLS‐DA) showed that there were significant differences in flavor among fish floss samples. The correlation analysis of browning index, fatty acids, and key volatile compounds confirmed that MR and lipid oxidation made a great contribution to the flavor formation. These results might provide guidance for the production and flavor formation of fish floss. Practical applications: Dried fish floss deeply loved by the public is a traditional leisure food with unique odor and delicious taste. The attractive flavor of dried fish floss could be increased with the help of the Maillard reaction (MR). The type of sugar in MR has a great influence on the reaction process and the flavor of substances. The comprehensive information on the flavor among the dried fish floss with different sugar (sucrose, glucose, xylose, fructose, and galactose) was characterized by using HS‐SPME/GC‐MS, electronic nose (E‐nose), and fatty acid analysis, which may provide a reference for the quality improvement of dried fish floss. [ABSTRACT FROM AUTHOR]

Bamboo shoot dietary fiber was added into dough to study the processing characteristics and moisture distribution of the repeated freeze-thaw dough. The results showed that the hardness of the dough in the control group increased first and then decreased, the viscosity and the chewiness increased, the elasticity became smaller. However, the hardness, viscosity and elasticity of the dough added with BSDF had not been significantly affected during the process of repeated freezing and thawing. When the number of repeated freeze-thaw cycles exceeded one time, the modulus of elasticity and viscosity of the BSDF dough increased, and the loss angle tangent decreased. During the process of repeated freezing and thawing,the deep layer bound moisture content of the dough in the control group decreased, while the weakly bound water and free water content increased. However, the addition of BSDF made the deep layer bound moisture content increased, the weakly bound moisture content decreased, and the free moisture content did not change significantly. [ABSTRACT FROM AUTHOR]

Wheat starch was used as the research object, and ultrasonic treatment was carried out at different times (0 min,10 min,20 min,30 min) so as to investigate the effect of ultrasonic treatment on its aggregation structure, solubility, swelling degree, pasting properties and rheological properties. The results showed that ultrasonic treatment disrupted the granular structure, crystalline structure and short-range ordered structure of wheat starch, inducing the amorphization of starch aggregation structure were deeper. And these transformations were more obvious with the increase of ultrasound time. Moreover, due to the destruction of starch aggregation structure, the solubility, swelling degree, peak viscosity, final viscosity and setback value increased, but the disintegration value reduced and the rigidity of starch gel decreased. [ABSTRACT FROM AUTHOR]

Potato protein microgel ( PPM2, PPM4, PPM6, PPM8 ) were prepared at different mass fractions (2%, 4%, 6%, 8%). The particle size, Zeta-potential, fluorescence characteristic, emulsifying activity, emulsion stability and microstructure of of microgel were investigated. The effect of potato protein microgel on the emulsification characteristics of Pickering emulsion was studied. The results showed that the particle size of the microgel particles increased significantly (116. 31 ~181.99 nm) with the increase of protein fraction during microgel preparation. The Zeta-potentials of PPM2, PPM4 and PPM6 were about 30 mV and higher than that of the control group. The fluorescence intensity of PPM2, PPM4 and PPM6 was higher than that of the control group, while the fluorescence intensity of PPM8 was lower than that of the control group. Compared with the control group, the microgel significantly improved the emulsion activity and emulsion stability of the Pickering emulsion. The microstructure results showed that the surface of the control group and all potato protein microgel were smooth, the control group was spherical, the potato protein microgel was aggregated in a sheet form, and the aggregation unit was larger with the increase of the potato protein mass fraction. [ABSTRACT FROM AUTHOR]

The modifications of histological properties and chemical forces on heated surimi gels with starch addition (0–12 g/100 g surimi) were investigated. Two types of heating processes (direct heating and two-step heating) were carried out on surimi gels in order to reveal the effect of setting on mixed matrices. The results of transverse relaxation time showed less immobile water and free water converted into bound water in a matrix subjected to the setting process. Scanning electron microscope and light microscopy images revealed inefficient starch-swelling in two-step heated gels. Chemical interactions and forces in direct cooking gels were more vulnerable to starch addition, resulting in significant decreases in hydrophobic interaction and sulfhydryl content (p < 0.05). With the increment of starch, the disulfide stretching vibrations of the gauche–gauche–gauche conformation were reduced in both gel matrices. The structural variations of different components collectively resulted in changes in texture profile analysis and water holding capacity. Overall, the results demonstrated that starch addition had a great and positive effect on the weak gel matrix by direct heating. [ABSTRACT FROM AUTHOR]

• Effect of heat-moisture treatment (HMT) on starch in adlay seeds were revealed. • HMT could alter the hierarchical structures of starch in adlay seeds. • HMT reduced the digested ratio and rate of starch in adlay seeds. • The new ordered structure formed during HMT weakened starch digestibility. • HMT effects on starch in adlay seeds are intensified by treatment moisture content. In the present study, starches isolated from heat-moisture treated (HMT) adlay seeds were characterized with hierarchical structures and digestibility to understand the relationships in structural and digestible behaviors of starches in a HMT starch-based food system. The results indicated that HMT not only caused the disorganizations of hierarchical structures, but also promoted the molecular rearrangements and reassembly of starch chains to form a new ordered molecular aggregation architecture (i.e. , highly ordered molecular structure, amylose-lipids complexes and thicker crystalline lamella). And the reinforced molecular interactions between starch molecules during HMT occurred to form more densely ordered structure, thus reducing the digestibility and digestion rate coefficients (k) of adlay starch. Particularly, HMT applied directly in adlay seeds with 30% moisture content displayed the highest resistant starch level (20.6%) and lowest k (2.74 × 10−3 min−1). Thus, the results are useful to realize the desired regulation of starch digestibility in adlay products following HMT. [ABSTRACT FROM AUTHOR]