Deciphering the interaction mechanism between Litsea pungens Hemsl. Oil (LPHO) characteristic flavor substances and starch in complexation behavior.

Cold-eating rabbit is a local specialty, combined with three different pretreatment methods commonly used in the industry such as directly making, fried after removing blood, and stir-fry after marinating to study the main flavor substances and effects of preconditioning on characteristic flavor compounds. Sensory analysis showed that umami was the strongest, which was the characteristic taste flavor, obtained from the taste substance detection experiment that Glu and 5′-IMP were the characteristic taste substances. Marinating process had a strong umami taste. Volatile flavor compounds were detected, and alcohols and aldehydes were the main volatile flavor substances. There were 23 kinds of volatile flavor substances and nine characteristic volatile flavor substances. The characteristic flavors were lemon, fat, barbecue, fruit, floral, fennel, and smoky flavor; among these, fat, barbecue, and floral flavor were the most obvious. Novelty impact statement This experiment was the first time to study the flavor substances and physical and chemical indexes of cold-eating rabbits, providing theoretical guidance for the industrial production of cold-eating rabbits in Zigong, China. Combined with three different preprocessing methods commonly used in the industrial production of cold-eating rabbits at the present stage, the influence of cold-eating rabbits' product flavor substances and the exploration of characteristic flavor substances were analyzed. This study concluded that the characteristics of the volatile flavor substances were lemon flavor, fat flavor, barbecue flavor, fruit flavor, flower flavor, fennel flavor, and smoke flavor; among these, fat flavor, the roasted meat, and floral aroma were the most obvious, and Glu and 5′-IMP were the characteristic taste substances.

Elucidating the effect of Litsea pungens Hemsl. oil (LPHO) with different crystalline starches complexed on flavor release and structural properties.

Comparison of the microbial community and flavor compounds in fermented mandarin fish (Siniperca chuatsi): Three typical types of Chinese fermented mandarin fish products

Inclusion complexation of flavour compounds by dispersed high-amylose maize starch (HAMS) in an aqueous model system

Edible mushrooms are rich in nutrition and have strong aroma as well as delicious umami taste. The flavor is not only the main indicator for evaluating the quality of edible mushrooms, but also an important factor influencing consumer preference. Thermal drying prolongs the shelf life of edible mushrooms, but it also causes modification of the flavor-containing components so that dried mushrooms show different flavor characteristics from those of fresh ones. As expected, different drying methods as operating conditions have important impact on product flavor. This paper discussed the formation pathways of the numerous flavor-containing compounds in foods; these include Maillard reaction, lipid oxidation and degradation, protein hydrolysis and Strecker degradation, as well as the main enzyme activity in aroma synthesis pathway. A comparison is presented of the effects of different drying conditions on flavor substances. The application prospects and possible development of more effective drying technology to ensure better retention of flavor in dried mushrooms so as to provide reference for the further research in production of high quality dried edible mushrooms.

Study on multiscale structures and digestibility of cassava starch and medium-chain fatty acids complexes using molecular simulation techniques

Exploring the regulation of metabolic changes mediated by different combined starter cultures on the characteristic flavor compounds and quality of Sichuan-style fermented sausages.

An electron paramagnetic resonance (EPR) study was performed for potato and wheat starch containing Cu2+ ions as a paramagnetic probe. Distribution of water in the starch granules as well as the interactions between the copper and starch matrix of different crystalline structures were determined. EPR spectra of the native starches consisted of two different centers of Cu2+. One of them, giving at 293 and 77 K an EPR signal of axial symmetry with a well-resolved hyperfine structure (HFS), was assigned to the Cu2+ -starch complex in which Cu2+ ions strongly interacted with oxygen atoms of the starch matrix. Another Cu2+ species, exhibiting an isotropic signal at 293 K and an axial signal with resolved HFS at 77 K, was attributed to a [Cu(H2O)6]2+ complex freely rotating at room temperature and immobilized at low temperatures. Interaction of Cu2+ with the starch matrix and the relative number of the particular copper species depended on the crystallographic type of starch. Dehydration at 393 K resulted in elimination of the rotating complex signal and decrease of the total intensity of the EPR spectrum caused by clustering of the Cu2+ ions. Freezing at 77 K and thawing led to restoring of the spectrum intensity and reappearing of the signal of the [Cu(H2O)6]2+ complex. This effect, related to liberation of water molecules from the granule semicrystalline growth rings on freezing/thawing, was especially visible for wheat starch, indicating differences in the water retention ability of starch granules of different crystallographic structure.

Hypsizygus marmoreus mushroom is known for its pleasant flavour and delicious taste. However, its flavour quality deteriorates rapidly during postharvest storage. In the present work, we explored the dynamic changes in flavour-presenting substances and taste components in H. marmoreus packaged in polyethylene nanofilm (0.05 mm) during low temperature storage (12 days). We used headspace solid-phase microextraction combined with gas chromatography-mass spectrometry to analyse the volatile flavour components; high performance liquid chromatography and liquid chromatography-mass spectrometry to analyse the non-volatile flavour (taste-presenting) substances (e.g., soluble sugars, taste nucleotides, free amino acids, and organic acids); and the relative odour activity value (ROAV) and taste active value (TAV) methods to determine the flavour substances in fresh and stored H. marmoreus. Results revealed that n-octanal, 1-octene-3-one, and 1-octene-3-ol were the characteristic volatile flavour substances, and that trans-2-octenal was the key substance affecting the formation of volatile flavours in fresh H. marmoreus. Trans,trans-2,4-nonadienal, and 3-octanone were the key volatile substances that resulted in flavour deterioration. Among the non-volatile flavour substances, trehalose, 5'-GMP, glutamic acid, alanine, and arginine were the key taste-presenting substances. In addition, oxalic acid and lysine were the key taste substances after H. marmoreus deterioration. These results provided a theoretical basis for rapid quality detection, flavour identification, and shelf-life prediction of H. marmoreus.

To screen rice varieties with high storage stability for eating quality and elucidate their traits, 34 widely grown rice varieties were selected to examine the changes in the eating quality of their grains after natural storage for one year. A hierarchical analysis, normalization method, and cluster analysis were used to identify the rice varieties that maintained their eating quality during storage. Meanwhile, the yield and its components, panicle traits, grain size, grain major component content, physiological indicators (such as antioxidant enzyme activity), and key growth stages were analyzed at rice maturity. The results showed that after storage, the values of the appearance, texture, and taste of the cooked rice decreased by 18.7%, 19.1%, and 14.2%, respectively. The storage stability of the eating quality of rice was evaluated using a hierarchical analysis based on the storage stability scores of the appearance, texture, and taste of the cooked rice. A judgment matrix was established, where the corresponding weights of the appearance, texture, and taste of the cooked rice were identified to be 0.105, 0.259, and 0.637, respectively. Based on a cluster analysis and the normalization method, these varieties were classified into three categories regarding the storage stability of their eating quality: high storage stability, intermediate storage stability, and low storage stability, accounting for 14.7%, 52.9%, and 32.4%, respectively. Finally, five rice varieties with high storage stability were screened. These varieties exhibited storage stability scores of the appearance, texture, and taste of cooked rice that were 215%, 219%, and 340% higher than those of the low storage stability type, respectively. The correlation analysis revealed that the storage stability of the eating quality of the rice was significantly and negatively correlated with amylose starch content, peroxidase activity, and malondialdehyde content. The amylose starch content, peroxidase activity, and malondialdehyde content of the high storage stability type were 12.4%, 35.9%, and 6.42% lower than those of the low-storage-stability variety, respectively. Therefore, the major features of rice varieties with high storage stability included low amylose starch content, diminished peroxidase activity, and low malondialdehyde content. This study provides valuable theoretical insights into the safe storage of rice grains and the selection and breeding of rice varieties with high storage stability.

One‐component epoxy adhesives have great promising prospects in industrial applications. However, it faces the challenge to reduce the activity of curing agents for achieving long‐term storage and controlled release. Microencapsulation is a feasible and effective solution. In this paper, multi‐polyaniline (MPAN) was successfully encapsulated with polyetherimide (PEI), a thermoplastic resin, as the shell material by using solvent evaporation method with dichloromethane (DCM) as solvent. The impacts of different preparation parameters on the structure and properties of microcapsules were investigated by single variable control method. It is found that the resulted microcapsules under the optimal process parameters, namely PVA concentration 1 wt%, core/shell mass ratio 1:1 and stirring rate 700 rpm, exhibits a smooth and dense spherical surface with an average particle size concentrated around 17.8 μm. Compared with the pure curing agent, the encapsulated curing agent effectively prolonged the shelf life of the epoxy adhesive at 40°C for at least 60 days, indicating excellent storage stability. The microencapsulated MPAN curing agent prepared in our research is of potential applications in the fields of electronic component bonding, potting and circuit board sealing due to its high storage stability and encapsulation efficiency (74%).

Rice, a staple global food crop, requires the maintenance of its quality stability during storage. This study aimed to screen rice varieties with high storage stability and elucidate their traits. Thirty-four widely cultivated varieties were selected to examine the changes in grain quality after one-year natural storage. The normalization method, hierarchical analysis, and cluster analysis were used to identify rice varieties maintaining their grain quality during storage. Meanwhile, the yield and its components, panicle traits, grain size, grain major component content, physiological indicators (such as antioxidant enzyme activity), and key growth stages were analyzed at rice maturity. The results showed that the processing, appearance, and eating quality of rice declined after storage. Specifically, the chalkiness degree increased significantly by 32.4%, while the cooked rice appearance, texture, and taste quality decreased significantly by 18.7%, 19.1%, and 14.2%, respectively. The grain quality storage stability was evaluated using a hierarchical analysis method based on the storage stability scores of the brown rice rate, milled rice rate, head milled rice rate, chalkiness degree, cooked rice appearance, cooked rice texture, and cooked rice taste. A judgment matrix was established, determining their corresponding weights of 0.0149, 0.0369, 0.0910, 0.286, 0.060, 0.148, and 0.364, respectively. Based on cluster analysis and the normalization method, these varieties were classified into three categories: high storage stability, intermediate storage stability, and low storage stability, accounting for 26.5%, 52.9%, and 20.6%, respectively. Finally, nine rice varieties with high storage stability were screened. The validation results of the principal component analysis also indicated the reliability of this result. Correlation analysis revealed that the storage stability of the rice grain quality was significantly and negatively correlated with the amylose starch content and malondialdehyde content. The average value and median value of the amylose starch content in high-storage-stability varieties are 10.7% and 6.99% lower than those in sensitive varieties, respectively. Therefore, the major feature of rice varieties with high storage stability is a low amylose starch content. This study provides valuable theoretical insights into the safe storage of rice grains and the selection and breeding of rice varieties with high storage stability.

The assembly of dyes molecules on metal-polymer complexes is of interest due to their potential applications in photovoltaic cell, separation, and wastewater treatment. In the present work, the interaction of anionic dyes (acid orange 7, acid orange 10, acid green 25, and acid red 18) with the copper(II) complex of dithiocarbamate-modified starch (DTCSCu) was investigated. The sorption studies showed that the interaction mechanism was based on chelating adsorption. The equilibrium data fitted well with Langmuir-Freundlich isotherm, and the capacities followed the order AO7 > AG25 > AR18 > AO10. It was affected by the structure of the dye. The sulfonate groups located on benzene rings favored efficient adsorption. Despite the difference in capacity, the molar n(dye):n(Cu) ratios for acid orange 10, acid red 18, and acid green 25 were approximately 1:2 when the maximum capacities for the dyes were achieved at the optimal pH of 4. It suggested that one dye molecule bound to one dinuclear copper center on DTCSCu. The molar n(dye):n(Cu) ratio for the smallest dye, acid orange 7 (AO7), approached 1:1, demonstrating two AO7 molecules binding to two copper ions of the dinuclear core. The dyes adsorption related to the dinuclear copper core available on the polymer was further verified by electron spin resonance studies. Such interaction resulted in the formation of a ternary dye-metal-polymer complex. The ternary complexes were more stable than DTCSCu, which favored the adsorptions.

Machine learning and GC-MS revealing the characteristic flavour compounds of Cheddar cheese origin-independent at different ripening periods.

From the wider point of view in Dairy industry, there are two groups of micro-o ganism, useful ones and harmful ones. Here I am going to discuss only about the application of useful one.1. Whipped cream:In whippod cream, whipping quality, stability of its body and texture and its characteristic flavour are required, on which the multiplication of St. lactis and the formation of proper acidity have influence.2. Butter and its flavour.In butter making, the fermentation of cream does not only make churning easy, but give its characteri tic flavour to butter. What make churning easy is acidity. And this acidity also helps to give uniformity to the pro ucts and ha good effect on its keeping quality. To this process, St. lactis has relation.As for the aroma of butter, at least two kinds of bacteria, besides St. lactis, work at the fermentation of cream, St. Citrovorus and St. Paracitrovorus. It is possible to give stronger aroma by culturing these bacteria by adding citric acid or its natrium salts to the milk for starter or raw cream itself.Moreover, one factor of the aroma of butter is deamed to be Diacetyl CH3 CO-COCH3, which is formed by oxidation of Acetyl methyl-carbinol CH3CO-CHOH-CH3 caused by micro-organisms at the ripening of cream.3. Margarine and its' flavour.To give the flavour of the natural butter to margarine, we use sour milk at the making process. As the flavour of butter has relation to Diacetyl, the pecial culture of the bacteria concerned in milk can be taken into consideration.This Diacetyl can be formed artificially, and applied for improving the flavour of margarine.4. Cheese and its making process:In chee e micro-organisms have relation from the beginnig of the making process to the end of curing. During the ripening of raw milk, and at cooking and cheddaring, chiefly St. lactis works. During the ripening period, besides St. lactis other kinds of bacteria, according to the kinds of cheese respectively, work and accomplish the ripening and make each kinds of special quality. These organisms are cultured purely and applied as starter. In milk products, nothing is made by more clever application of micro-organisms than chee e.5. Kinds of cheese and special organisms:The kinds of cheese are so various, and to each special starter is used, re ulting in each special flavour, texture and property. Here are some examples:(1) Cheddar cheese. In the ripening of this cheese, at least two groups of bacteria play the role. One of them is a group of St. lactis, which multiply actively during early stage of fermentation. The other is Lactobacilli, which starting when the former one's multiplication ceases, multiply vigorouoly during the later stage, taking part in the recomposition of protein and the origination of flavour.(2) Emmenthal cheese. To the formation of "Eyes" and the special sweet flavour, characteristic to this chees, concernes B. acid propionici. Besides, L. bulgarics, L. casei and St. thermophilus has relation.(3) Roquefort cheese. This cheese is other wise called marbled cheese, from its marbled section, made by the multiplication of a mould even in the inside of cheese. From the colour of marbling, it is alao called "blue veined cheese".This blue mould is Penicillium roqueforti which concerns its special acrid taste and its complex flavour. In ripening, other bacteria take part, too, and one of the ingredients of the flavour is methyl-n-amyl Ketone.(4) Camembert chaese. The particular sharp flavour of this chee a has relation to the special mould, P., camamberti.6. Evadorated acid skim-milk and semi-solid butter milk.Being of high acidity, above 3.5%, they are of good. keeping quality and of high nutritive value as feeds for poultry and swine.