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The effects of microwave drying (MD), hot air drying (HAD), vacuum hot air drying (VD), and vacuum freeze drying (VFD) on the volatile profiles of Penaeus vannamei were investigated. A total of 89 and 94 volatile compounds were identified by headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPME-GC–MS) and monolithic material sorptive extraction gas chromatography–mass spectrometry (MMSE-GC–MS), respectively. Orthogonal partial least squares-discriminant analysis (OPLS-DA) and variable influence on projection (VIP) models were utilized to select characteristic volatiles and key marker compounds (e.g., octanal, 1-octen-3-ol, 2-methyl-butanal, 2-ethyl-furan, and trimethyl-pyrazine) to discriminate among four drying methods. Based on synthesis of odor descriptions and sensory evaluation, it was found that P. vannamei via MD, HAD, and VD greatly reduced the fishy and generated roasted, fatty, and smoked odors. This study systematically analyzed the aroma characteristics of four traditional dried P. vannamei products, which may provide theoretical guidance for industrial production. [Display omitted] • Drying reduced fishy odor and provided roasted and smoked smells. • Marker chemicals were found to distinguish among drying methods. • Combining OAV and VIP to analyze the distinctive aroma formation. • Combining MMSE and SPME extractions for precise detection. [ABSTRACT FROM AUTHOR]

The effects of heating temperatures (60–100 °C) on the morphology and structure of surimi gels with or without starch addition (potato and tapioca starch) were investigated in order to determine the reasons behind variations in the textural properties of starch-surimi gels. As shown by an improvement in hardness and gel strength as well as microstructural homogeneity, starch addition was beneficial in mitigating gel deterioration caused by rising temperatures. Scanning electron microscope and light microscope images showed that the starch swelling ratio improved as heating temperatures increased, resulting in an enhancement in cohesiveness and water holding capacity. Fourier transform infrared spectroscopy results revealed that an absorption peak of 900–1200 cm−1 indicated the turning point for starch structural alterations. Despite the fact that starch attained active filling at high temperatures, surimi proteins aggregated and starch cavities developed, which reduced the gel texture. This study laid the groundwork for understanding the effect of morphological and structural changes in starch on surimi gels. [ABSTRACT FROM AUTHOR]

• Germination increased the activities of α-amylase in GBR. • Germination altered structures and pasting properties of starch in brown rice. • The alternations in hierarchical structures were impacted by α -amylase activities in GBR. • Germination reduced the paste viscosity throughout the pasting course. • A structure-property relationship was established for the native and germinated starches. The study aimed to obtain the information on the effect of germination temperature on hierarchical structures (granular structure, crystal structure, short-range ordered structure and helical structures) of starch from brown rice and their relation to pasting properties. The results showed that brown rice had gradually elevated germination ability and α- amylase activity as the sprouting temperature rose. And the enhanced enzyme activities during germination promoted the erosion of starch granules, the decrease of relative crystallinity and short-range ordered degree, and the unwinding of double helix structure. In addition, the mathematical correlation and structure-pasting relationship were constructed in this work. These structural disorganizations of germinated rice starch resulted in reduced swelling degree and water-holding capacity, inducing the lower paste viscosity (e.g. , peak and final viscosity), breakdown and setback value. Thus, it is concluded that germination can efficiently regulate the pasting properties of starch, which provide a crucial basis for the development and utilization of germinated brown rice products. [ABSTRACT FROM AUTHOR]

Highlights • PGS addition led to enhanced viscosity and gel network for glutinous rice flour. • PGS addition induced structural disorganization for glutinous dumplings. • PGS addition improves storage and textural properties of glutinous dumplings. • PGS addition increases the SDS and bound water content of glutinous dumplings. • Statistical correlation found between flour properties and qualities of dumplings. Abstract In this study, the impacts of pregelatinized starch (PGS) with different conditions (2–8%, w/w) on the characteristics, microstructures and quality parameters of glutinous rice flour and dumplings were determined. The results indicated PGS favored the formation of elastic gel-like network structure on starch granules. PGS addition, especially at high PGS content, significantly influenced the granular, crystalline and molecular structure of glutinous dumplings, probably due to the structural amorphization of PGS. Accordingly, the dumplings complexation with suitable PGS exhibited a better storage, an increased content of slowly digestible starch (SDS), and integrated quality attributes including transmittance, cracking rate, and textural properties via weakening the water mobility. Pearson's correlation matrix exhibited that the quality of glutinous dumplings could be well predicted by physicochemical properties of rice flour. Thus, it is feasible to improve the textural and nutritional attribute of glutinous rice dumplings via simply complexation with PGS. [ABSTRACT FROM AUTHOR]

[Display omitted] • A total of 45 volatile compounds were identified from naturally fermented grass carp. • 13 volatile compounds (OAV ≥ 1) were identified as the key volatile compounds. • Lactiplantibacillus contributed significantly to the volatile flavor formation during natural fermentation of grass carp. Complex microbial communities contribute significantly to the flavor formation of traditional fermented fish products. However, the relationship between microorganisms and flavor formation in traditional fermented grass carp products is still unclear. In this study, the diversity and succession of microbial communities and the variation of volatile compounds during natural fermentation of grass carp were analyzed using high-throughput sequencing of 16S rRNA and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), respectively. The core functional microorganism and key volatile compounds were identified, and their potential relationship was revealed using a correlation network model analysis. The microbial community analysis result showed that the microbial diversity during natural fermentation of grass carp decreased markedly with increasing fermentation time, and Lactiplantibacillus , Staphylococcus , and Enterobacter were the dominant genera in naturally fermented grass carp. HS-SPME-GC-MS analysis result showed that 45 volatile compounds were identified from fermented samples, among which 13 compounds (e.g., hexanal, heptanal, nonanal, decanal, 3-octanone, 3-methyl-1-butanol, 1-hexanol, 1-heptanol, 1-octen-3-ol, 1-octanol, ethyl acetate, 3-methyl-1-butanol acetate, and 2-methoxy-4-vinylphenol) were identified as the key volatile compounds. Additionally, the correlation network model analysis result revealed that Lactiplantibacillus showed significantly positive correlations with most of the key volatile compounds, making an important contribution to the formation of volatile flavor in naturally fermented grass carp. This study may lead to an understanding of the role of core functional microorganisms in the formation of volatile flavor during the natural fermentation of grass carp and provide some theoretical guidance for the industrial production of high-quality fermented grass carp products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rinsing could significantly affect the aroma profiles of grass carp mince. • HS-SPME-GC-MS identified 57 volatile compounds in grass carp mince. • HS-GC-IMS identified 20 volatile compounds in grass carp mince. • The washing sample with a weak alkaline solution has better sensory acceptability. The aroma characteristics of grass carp mince washed in four processes were analyzed via electronic nose (E-nose), headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), and sensory analysis techniques. Significant differences were revealed in the E-nose and sensory analysis results of the aroma characteristics of grass carp mince samples washed via different washing processes, while fifty-seven volatile compounds (thirteen aldehydes, eighteen alcohols, two ketones, eighteen hydrocarbons, two aromatic compounds, one furan, and two other compounds) and twenty volatile compounds (five aldehydes, four ketones, six alcohols, four esters, and one acid) were identified via HS-SPME-GC-MS and HS-GC-IMS of the Raw and washed grass carp mince samples, respectively. All these techniques revealed that the types and relative contents of volatile compounds in the grass carp mince decreased significantly and differently after each of the four washing processes. Moreover, compared with the water and saline solution washing processes, washing with weak alkaline solution processes exhibited the most significant removal effect on the volatile compounds of grass carp mince. Besides, the sensory analysis results also showed that weak alkaline solution washing processes (washing twice with pure water and once with 0.3% sodium bicarbonate solution) may be most effective in removing fishy off-odor compounds and contributing to a better overall aroma profile in grass carp mince. The findings of this study may provide some basic knowledge for the rational screening of washing methods in the production of high-quality grass carp surimi. [ABSTRACT FROM AUTHOR]

This study aimed to investigate taste substances of shrimp heads stored at 20 °C, 4 °C, −3 °C, and − 18 °C, and the correlation between taste substances and 25 key volatile substances. Notably, samples stored at 20 °C showed significant changes in bitter amino acids and hypoxanthine, and quickly deteriorated. Samples stored at 4 °C for 14 d or − 3 °C for 30 d facilitated the development of umami amino acids, sweet amino acids, and IMP. Furthermore, samples stored at −18 °C for 30 d demonstrated no significant changes in taste profile. Changes in taste substances through quantitative analysis were consistent with changes in taste profile through e-tongue analysis. Based on the results of O2PLS (VIP > 1), Cys, Arg, Glu, Ser, Val, Ala, Ile, ADP, and IMP were correlated with 25 key volatile substances. This study provides fundamental data for the storage, transportation, and value-added utilization of shrimp heads. [Display omitted] • Comprehensive understanding of the changes in the taste substances of shrimp heads. • Storage at 4 °C and − 3 °C promoted the generation of taste substances in shrimp heads. • The correlation between flavor substances was identified by O2PLS-VIP value. [ABSTRACT FROM AUTHOR]

• The addition of glucose promoted the glycation reaction rate of silver carp mince (SCM). • Lysine and cysteine were the main amino acids involved in the glycation of SCM. • Glycation accelerated lipid oxidation and the production of Strecker aldehydes of SCM. • Glycation was positively correlated with volatile compounds. • Glycation can be used as a flavor enhancement technology for low-value fish. The purpose of this study was to explore the effect of glycation on physicochemical properties and volatile flavor characteristics of silver carp mince (SCM). The changes in the degree of grafting, chemical composition, pH, color, total amino acid composition, and volatile flavor compounds of SCM with or without glucose were studied at different heating times. The results showed that the addition of glucose could promote the glycation reaction rate of SCM. Lysine and cysteine were the main amino acids involved in glycation. Glycation enhanced the overall aroma of SCM by accelerating lipid oxidation and Strecker degradation. In conclusion, these results suggest that glycation can enhance the volatile flavor of SCM during thermal processing and can be used as a volatile flavor enhancement technology for the development of protein nutrition food with good flavor from low-value fish. [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]