Flavor Stability Research Articles

Development of emulsion-filled calcium alginate gels for thermoresponsive release of flavor in plant-based meat analogs

We developed emulsion-filled calcium alginate gels (EF-CAG) as a novel thermoresponsive carrier for plant-based meat analogs (PBMA), designed to mimic the cooking-induced flavor release of real meat. Optimized to maximize flavor release upon heating, EF-CAG demonstrated a thermoresponsive release of 51% with a notable size reduction. Initial release profiles varied between media; a burst release of 43% occurred in water within the first 5 min, while <1% was released in air. EF-CAG consistently increased flavor release in PBMA during cooking, without adversely affecting appearance or flavor stability, maintaining flavor retention at 4 °C for 10 days. The sensory evaluation confirmed that EF-CAG successfully masked the beef flavor before cooking and enhanced its release afterward. Our findings suggest that EF-CAG can be effectively used as a flavoring agent for PBMA, offering similar flavor attributes to real meat during cooking.

Impact of heat treatment on the flavor stability of Longjing green tea beverages: Metabolomic insights and sensory correlations

The flavor stability of tea beverages during storage has long been a concern. The study aimed to explore the flavor stability of Longjing green tea beverage using accelerated heat treatment trials, addressing the shortage of lengthy storage trials. Sensory evaluations revealed changes in bitterness, umami, overall harmonization, astringency, and ripeness as treatment duration increased. Accompanied by a decrease in L-values, ΔE and an increase in a and b-values. Seventeen non-volatile metabolites and three volatile metabolites were identified differential among samples by metabolomics, with subsequent correlation analysis indicating associations between sensory attributes and specific metabolites. Umami was linked to epigallocatechin 3,5-digallate and alpha-D-glucopyranose, astringency was correlated with ellagic acid and 1-ethyl-1H-pyrrole. Ripeness showed associations with ellagic acid, 6,7-dihydroxycoumarin, heptanal, and benzaldehyde, and overall harmonization was linked to 6,7-dihydroxycoumarin, β-myrcene, α-terpineol, and heptanal. A series of verification tests confirmed the feasibility of accelerated heat treatment trials to replace traditional storage trials. These results offer valuable insights into unraveling the complex relationship between sensory and chemical profiles of green tea beverages.

A Preliminary Study on the Effect of Adding Sugarcane Syrup on the Flavor of Barley Lager Fermentation.

This study focuses on the diversified utilization of the sugarcane industry, and sugarcane syrup, as a by-product of the sugarcane industry, is a good raw material for fermentation. Bringing sugarcane syrup into beer is conducive to the enrichment of the sugar industry, and it can improve the flavor of beer and make it more aromatic. This study determined the optimal fermentation process for beer. By analyzing the consumption rate of the carbon and nitrogen sources of raw materials, the nutrient utilization of yeast, and the causes of differences in flavor substances, the flavor composition and flavor stability of beer were determined by SPME-HS-GC-MS technology. The results showed that beer brewed with sugarcane syrup as an auxiliary raw material met the basic specifications of beer. The addition of sugarcane syrup to the wort base increased the utilization of amino acids by the yeast, and LS (lager with added cane syrup) increased the nine flavor compounds of the beer, which constituted the basic flavor of the beer, bringing new flavor compounds compared with the normal all-barley beer. Forced aging experiments showed that LS produced fewer aging compounds than OWBL. Various experiments have shown that it is feasible to ferment beer with sugarcane syrup instead of partial wort.

Differences in structure, stability and antioxidant activity of melanoidins from lager and ale beers

Beer melanoidins, the final products of the Maillard reaction (MR), play a critical role in determining the flavor stability of beer due to their antioxidant properties. This study investigated the structure, stability, and antioxidant activity of lager beer melanoidins (LBM) and ale beer melanoidins (ABM). The results revealed that ABM possessed a higher browning index and molecular weight, attribute to its relatively intense MR. However, this intensity also led to a more unfolded and disordered structure in ABM. Conversely, LBM outperformed ABM in the FAST index, thermal stability, and total antioxidant activity because the low alcohol content in lager beer reduced oxidation and thermal degradation while boosting the stability and antioxidant activity of melanoidins. As a result, it would offer a novel possibility to improve beer flavor stability by optimizing the brewing process to modify the structural and functional characteristics of melanoidins.

Quantitation of Key Antioxidants and Their Contribution to the Oxidative Stability of Beer.

A sensitive high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MSMRM) method, leveraging both technique and internal calibration, was developed for the simultaneous and comprehensive quantitative analysis of 46 antioxidants and antioxidant precursors in different beer types without any cleanup procedure. Combined with their in vitro antioxidant activity, a dose-activity estimation exposed a group of 10 key antioxidants, namely, tryptophan, tyrosine, hordatine A, hordatine B, procyanidin B3, prodelphinidin B3, tachioside (3-methoxy-4-hydroxyphenyl-β-d-glucopyranoside), (+)-catechin, tyrosol, and ferulic acid. To study the effect of antioxidants in spiking and aging studies, another liquid chromatography-MS (LC-MS)-based method was developed, monitoring markers for oxidation in beer. A positive effect of the antioxidants on the flavor stability at naturally relevant concentrations was shown by a slowing of oxygen-dependent aging reactions highlighted in beer storage trials under oxygen atmosphere. Thereby, a doubling of the natural concentration of all investigated antioxidants in beer revealed a limit inhibition of 67% on the degradation of cis-isocohumulone to hydroxy-cis-alloisocohumulone.

Quantitative Antioxidant Profiling Throughout Beer Brewing Followed by Discovery and Isolation of Precursors from Barley (Hordeum vulgare L.).

The application of high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) revealed the origin and evolution of antioxidants during the brewing process of hopped and unhopped reference beer. As tachioside (3-methoxy-4-hydroxyphenyl-β-d-glucopyranoside), arbutin (4-hydroxyphenyl-β-d-glucopyranoside), and hordatines clearly increased during the fermentation step, the raw material barley was investigated as a source of the corresponding precursors. Therefore, 4-hydroxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside, 4-hydroxy-3-methoxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside, 4-hydroxy-3-methoxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside, and 4-hydroxy-2-methoxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside were isolated from barley for the first time, and identified using liquid chromatography-mass spectrometry (LC-MS) and one-dimensional/two-dimensional-nuclear magnetic resonance (1D/2D-NMR) experiments. Moreover, hordatine glucosides A, B, and C were isolated and identified from barley, and hordatine C glucoside was characterized for the first time. A fermentation model followed by HPLC-MS/MS analysis substantiated the release of tachioside from 4-hydroxy-3-methoxyphenyl-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside by Saccharomyces cerevisiae. Quantitation experiments monitoring the content in wheat, barley, and different barley malt types demonstrated a wide range of concentrations, providing a basis for further comprehensive investigations to optimize the antioxidant yield in beer to contribute to improved flavor stability.

The control effect and mechanism of antioxidants on the flavor deterioration of Sichuan pepper essential oil during thermal processing

The impacts of varying heating temperature on the flavor of Sichuan pepper essential oil (SPEO) have been studied. The high temperature heating was found to accelerate the oxidation of SPEO and caused the deterioration of its flavor (odor and pungency taste). With the intervention of antioxidants including RE, AP, and TPP, both thermal oxidation stability and flavor stability of SPEO were enhanced. Addition of 1.5% TPP had the best control effect, which significantly improved the overall flavor of heated SPEO and made the overall flavor of SPEO heated at 100°C highly similar to that of original SPEO. According to the results of GC-MS and OAV analyses, the control effect of antioxidants on odor deterioration of SPEO was mainly through significantly inhibiting the decrease in content and OAV of both linalool and terpenes, and restricting the formation of some oxygenated compounds such as aldehydes. The results of HPLC analysis showed that the control effect of antioxidants on the thermal taste stability of SPEO was mainly dependent on blocking the chemical reactions of sanshools, especially hydroxy-α-sanshool.

Enhancing the Retention and Oxidative Stability of Volatile Flavors: A Novel Approach Utilizing O/W Pickering Emulsions Based on Agri-Food Byproducts and Spray-Drying.

Spray-drying is a commonly used method for producing powdered flavors, but the high temperatures involved often result in the loss of volatile molecules. To address this issue, our study focused on a novel approach: developing O/W Pickering emulsions with agri-food byproducts to encapsulate and protect D-limonene during spray-drying and storage. Emulsions formulated with lupin hull, lupin-byproduct (a water-insoluble protein-fiber byproduct derived from the production of lupin protein isolate), and camelina press-cake were subjected to spray-drying at 160 °C. The results revealed that these emulsions exhibited good stability against creaming. The characteristics of the dry emulsions (powders) were influenced by the concentration of byproducts. Quantitative analysis revealed that Pickering emulsions enhanced the retention of D-limonene during spray-drying, with the highest retention achieved using 3% lupin hull and 1% camelina press-cake. Notably, lupin-stabilized emulsions yielded powders with enhanced oxidative stability compared to those stabilized with camelina press-cake. Our findings highlight the potential of food-grade Pickering emulsions to improve the stability of volatile flavors during both processing and storage.

Oral soluble shell prepared from OSA starch incorporated with tea polyphenols for the microencapsulation of Sichuan pepper oleoresin: Characterization, flavor stability, release mechanisms and its application in mooncake

The market share of Sichuan pepper oleoresin (SPO) in the flavor industry is increasing steadily; however, its high volatility, low water solubility, and poor stability continue to pose significant challenges to application. The microencapsulation prepared by emulsion embedding and spray drying is considered as an effective technique to solve the above problems. Sodium octenyl succinate starch (OSA starch) and tea polyphenols (TPs) were used to develop OSA-TPs complex as encapsulants for SPO to prepare orally soluble microcapsules. And the optimum doping of TPs was determined. SPO microcapsules have good properties with high encapsulation efficiency up to 88.13 ± 1.48% and high payload up to 41.58 ± 1.86% with low water content and high heat resistance. The binding mechanism of OSA starch with TPs and its regulation mechanism and effect on SPOs were further analyzed and clarified. The binding mechanism between OSA starch and TPs was clarified in further analyses. The OSA-TPs complexes enhanced the rehydration, release in food matrix and storage stability of SPO, and exhibited good sensory immediacy. Flavor-improved mooncakes were successfully developed, achieving the combination of mooncake flavor and SPO flavor. This study provided a valuable way to prepare flavoring microcapsules suitable for the catering industry, opened up the combined application of SPO and bakery ingredients, and was of great practical value and significance for improving the processing quality of flavor foods, driving the development of the SPO industry, and enhancing the national dietary experience.

Synthesis and pyrolysis of polyacrylate-supported flavor precursors

Herein we present a novel ‘polymerization strategy’ aimed at synthesizing flavor precursors, with a focus on enhancing their thermal stability and release properties. Three volatile flavors, menthol, methyl cyclopentenolone, and ethyl maltol, are reacted with acryloyl chloride to produce corresponding vinyl monomers. These monomers undergo radical polymerization to form homopolymers (P1−P3). To improve solubility in alcohol solvents, a hydrophilic oligoethylene glycol monomer is introduced, copolymerized with the flavor containing monomers, resulting in copolymers (P4−P6). An important advantage of these polymers lies in their significantly enhanced thermal stability, exhibiting an increase of approximately 100 to 200 °°C compared to small molecular flavors. Furthermore, our methodology enables efficient release of the target flavors upon heating, as evidenced by online analyses of volatiles from pyrolysis using fixed-bed reactor combined with single photoionization mass spectrometry (FBR-SPIMS) and pyrolysis-gas chromatography-mass spectrometry (Py-GC–MS). This work represents a practical and innovative approach to improving the thermal stability of volatile flavors and elevating their release temperature, offering promising applications in high-temperature food processing and tobacco industries.

Sulfite Management during Vinification and Impact on the Flavor of Solaris Wine

Effective sulfur dioxide (SO2) management is crucial in winemaking to minimize oxidative changes in wine flavor during storage. This study explored the impact of various SO2 management techniques on Solaris white wine’s flavor components and sensory properties. Five treatments were administered: ‘SO2 in juice’ (50 mg/L SO2 added to juice pre-fermentation), ‘Control’ (60 mg/L SO2 added post-fermentation), ‘Low SO2’ (50 mg/L SO2 post-fermentation), ‘High SO2’ (100 mg/L SO2 post-fermentation), and ‘No SO2’ (no SO2 added). The ‘Control’ followed a standard procedure, in which the achieved level of free sulfite is measured and extra SO2 added to reach the recommended level of free sulfite for the pH of the wine. Here, 50 + 10 mg/L was added. Volatile compounds were analyzed using dynamic headspace sampling coupled with gas chromatography–mass spectrometry after 0, 3, 6, and 12 months of storage. Sensory evaluation by a trained panel after 12 months revealed stronger perceptions of ‘overall impression’, ‘chemical’, ‘bitter’, ‘overripe fruit’, and ‘honey’ notes in the ‘No SO2’ and ‘SO2 in juice’ wines. The data underscore the significant influence of SO2 management on the flavor stability of Solaris white wines, emphasizing the need for strategic SO2 interventions during winemaking to enhance sensory quality over time.

An investigation of the shelf life of cold brew coffee and the influence of extraction temperature using chemical, microbial, and sensory analysis.

This study advances the industry's understanding of the shelf life of ready-to-drink bottled cold coffees and demonstrates that lower brewing temperatures lead to greater flavor stability over shelf life. The findings also provide brewing parameters that can help guide product developers in modulating the flavor of commercial cold coffees.

Thermal stability of banana and strawberry flavouring food additives

Food additives are substances or mixtures of substances added to food products in a set amount to maintain or increase their safety, freshness, taste, nutritional values, texture and appearance. Heat treatment is frequently used for food and consequently the processes in which the additive that is added to the raw material participates must also be studied. In this study, the results of the thermal analysis of two flavors used especially in the processing of confectionery products, banana and strawberry flavours, in an inert atmosphere of nitrogen gas are presented. Experimental results indicate a lower relative stability of banana flavor (180 °C) compared to strawberry flavor (225 °C).

Stabilization Effect of Potato Starch on Characteristic Flavor Compounds in Onion Sauce

AbstractThe food industry is experiencing a substantial demand for transitioning to natural flavors. Nonetheless, the challenge lies in the inherent instability of most flavor molecules when removed from their original sources. Three representative flavor compounds, including dipropyl disulfide (DD), allyl mercaptan (AM), and dimethyl trisulfide (DT), are selected to form composites with potato starch (PS) to protect them from decomposition or transformation. Then, their physicochemical properties and microstructures are investigated using combined methods. PS can combine with these sulfides mainly through its amylose, and thioethers are more likely to interact with PS than mercaptan. All the composites have lower phase transition temperature and higher enthalpy values than PS, and PS‐AM exhibits the largest stability followed by PS‐DD and PS‐DT. The sulfides interact with PS by entering into the helical cavity of its amylose mainly through hydrophobic interaction and increase the long‐range ordered degree and short‐range ordered degree of the composites. DD, AM, and DT can form V‐type inclusion composites with PS, which reserves more DD and AM to delay flavor degradation and enhances the flavor stability of onion sauce. This study can provide valuable reference for the preservation of characteristic flavors of allium food products during thermal processing and storage.

The impact of lager brewing yeasts on flavor stability of pilot-scale beer during storage

AbstractThe aim of the present study was to investigate the impact of two lager brewing yeasts (KVL001 and KVL018), known to produce different levels of sulfite and thioredoxin, on the flavor stability of beer during storage for 24 weeks at 25 °C and 35 °C. Fermentations with the two yeast strains were carried out in two identical pilot scale brews and provided fresh beers with very similar sensory profiles, only differing significantly in content of sulfite, iron, thioredoxin, and free amino acids. No difference in protein thiols was observed indicating that thioredoxin was not active in the final beer. The yeast strain KVL018 consumed less free amino acids than KVL001 resulting in fresh beers with a higher content of free amino acids. During storage, the beers developed very similarly, but the beers fermented with KVL018 developed more 'fruity aged/vinous' flavor, especially at 35 °C. This suggested that a higher degree of the Maillard reaction took place in these beers due to the higher content of free amino acids. Beers fermented with KVL018 also contained more sulfite and less iron, but scored lower in the general evaluation of the sensory analysis. In conclusion, our results indicate that the yeast strain (KVL001) taking up more free amino acids resulted in more flavor-stable beer due to a lower degree of the Maillard reaction, while no clear effects were observed on oxidation.

Formation of staling aldehydes in different grain bed layers in an industrial scale maltings

Understanding the contribution of raw materials to the quality of the final product is crucial for the food industry. In the brewing process, malt delivers various compounds that compromise the flavour stability of beer, including staling aldehydes and their precursors. The primary aim of this study was to investigate the evolution of staling aldehydes and their cysteinylated counterparts throughout industrial scale pale malt production. The second objective was to study the extent to which process related gradients (e.g., temperature, moisture) may contribute to the differential formation of free and bound state aldehydes. Samples were collected from two industrial scale, pale lager malt production processes as a function of process time (germination, kilning, and cooling) and the position of the kernals in the grain bed (bottom, middle and top layers) during kilning. The levels of free and cysteinylated aldehydes were determined. The results show that the initial stage of germination is accompanied by enzymatic fatty acid oxidation as reflected by the formation of hexanal and trans-2-nonenal. Drying at elevated temperature (at a critical moisture content of 6-9%) results in the intensified formation of cysteinylated Strecker aldehydes and furfural. Moreover, a rapid increase in the formation of (cysteinylated) Strecker aldehydes furfural and trans-2-nonenal continued through kilning. A clear effect of temperature and moisture gradients was observed on the formation of aldehydes and it is concluded that exposure to heat load plays a critical role in the development of cysteinylated aldehydes during malt production. This publication is dedicated to the memory of Professor Luc De Cooman.

Effects of Dry-Hopping on Beer Chemistry and Sensory Properties-A Review.

Dry-hopping is the addition of hops to the wort on the cold side of the brewing process. Unlike standard hop additions, its main purpose is not to produce a characteristic bitterness but to extract as much of the hop essential oils as possible, which are largely lost in the standard hopping process. When dry-hopped, it is possible to obtain a beer with an aroma that is difficult to achieve when hops are used on the hot side of the brewing process. As a result, this process has become very popular in recent years, particularly in beers that belong to the 'craft beer revolution' trend. In addition, the usefulness of this process is increasing with the development of new hop varieties with unique aromas. This article presents the main components of hops, focusing on those extracted during the process. Changes in the composition of beer bittering compounds and essential oils resulting from this process are discussed. This paper presents the current state of the knowledge on the factors affecting the degree of extraction, such as hop dosage, the time, and temperature of the process. Issues such as process-related physicochemical changes, hop creep, low flavor stability, haze formation, and green flavor are also discussed.

Untargeted metabolomics coupled with chemometrics for flavor analysis of Dahongpao oolong tea beverages under different storage conditions

The stability of flavor in ready-to-drink tea beverages has been a pressing concern for the tea beverage industry. This study aimed to investigate the flavor quality changes in Dahongpao oolong tea beverages stored under different conditions (4 °C and 37 °C) using ultra-high-performance liquid chromatography coupled with ultra-high-performance liquid chromatography-quadrupole exactive-orbitrap mass spectrometry and headspace solid phase micro-extraction-gas chromatography-mass spectrometry. The results revealed that, compared to the samples stored at 4 °C, those stored at 37 °C exhibited noticeable color changes, transitioning from a mellower and sweet aftertaste to a riper and coarser flavor profile, with a decrease in roasted aroma. Utilizing orthogonal partial least square discriminant analysis, 37 key taste substances were identified, including gallic acid, catechin, 3-O-p-coumaroylquinic acid, epigallocatechin gallate, and ellagic acid, which experienced changes of 358.50%, 90.35%, 207.59%, −98.98%, and 866.10%, respectively (4 °C→37 °C). Moreover, through chemometric analysis and relative odor activity values＞1, β-damascone, linalool, and 2-ethyl-5-methyl pyrazine were identified as key contributors, with the carotenoid-derived pathway playing a more significant role. This study provides valuable insights for understanding and addressing flavor stability in tea beverages.

Effect on lipoxygenase pathway and flavor stabilization of postharvest strawberries by intense pulsed light treatment

A non-thermal pretreatment method was developed to improve the flavor stability of strawberries using an intense pulsed light during postharvest storage. The physicochemical properties, volatile organic compounds (free and bound), enzyme activities, and key gene expressions were investigated during 7-day storage. A 23.67% decrease in the decay ratio was obtained in IPL-treated with 2.0 Hz frequency for 60 s compared to the control. A more stable surface color was obtained at the end of the storage period. A total of 21 f-VOCs and 13 b-VOCs were quantitatively identified. IPL treatment promoted the contents of free aldehydes, esters, and ketones. The content of (E)− 2-heptenal in the IPL-treated strawberries was 1.90 times higher than that in control. The variation in the total content of b-VOCs was less than 31.61% that in the control group. Correspondingly, IPL treatment inhibited the activities of fatty acid metabolism enzymes and decreased LOX activity by 26.3% after storage. Aroma-related genes, including FaLOX, FaADH, and FaAAT, were down-regulated in the metabolism of specific VOCs following IPL treatment. This work provided evidence about the practical application of IPL in inhibiting the activity of enzyme in the LOX pathway, thereby improving the flavor stability of strawberries under non-thermal process conditions.

Enhancement of dimethyl sulphide separation during wort boiling by a single spinning cone evaporator

Wort boiling is the most energy intensive stage in the brewing process. Novel wort boiling systems have been explored to reduce primary energy consumption and improve wort quality and beer flavor stability. Low thermal stress boiling is proposed for wort boiling, but the content of dimethyl sulphide (DMS) in the wort may exceed the required product threshold. A single spinning cone evaporator (SCE) is proposed to enhance the separation of DMS and minimise the energy consumption for wortboiling. The performance of a SCE was evaluated by measurement of fluid flow, ratio of DMS removal, wort self-evaporation ratio based on sensible heat, and thermal efficiency. The results show that use of a spinning cone evaporator, reduced DMS by up to 90% with 2.1% wort self evaporation ratio with less primary heat consumption. The SCE operation exceeds the evaporation of a gravity film cone. Under reduced pressure, the spinning cone evaporator was less effective in DMS removal.