Flavor Delivery Research Articles

Temperature‐responsive palm oil‐based‐oleogels for encapsulation of D‐limonene: effect of fat crystallisation and melting point

SummaryD‐limonene is an important flavouring ingredient with a wide range of applications. However, its high volatility and low stability have severely impacted its application in the food industry. To address these limitations, temperature‐flavour release control system is expected to be established to reduce the loss of D‐limonene during processing and storage, as well as to control its release by temperature. The aim of the current study is to construct an oleogel system to encapsulate D‐limonene using carnauba wax as a gelling agent and palm oils (POs) as the base oil. POs with 24 °C, 38 °C, 42 °C, 48 °C, and 52 °C melting points were selected to systematically investigate the effects of the base oil melting point on the crystal morphology, interactions, physicochemical properties, microstructure, and D‐limonene release of the oleogels. The enthalpy of melting, enthalpy of crystallisation, hardness, stickiness, and gel strength increased in oleogels prepared using POs with a higher melting point. In addition, the oil‐binding capacity (OBC) (>95%) of the oleogels increased with the base oil melting point, while the fat crystal distribution became more homogeneous and denser. Based on the influence that extraction temperature has on the concentration of released D‐limonene (a lower concentration of aroma was released from high‐melting‐point POs oleogels at low temperatures (<1.9 mg mL−1), whereas the control group released >2.5 mg mL−1), suitable POs can be selected to achieve the release or retention of the aroma. These results demonstrate that a temperature‐responsive flavour delivery system can be prepared with different PO melting points. The molecular dynamics of flavour release revealed that storage temperature and fat crystalline state impact the cumulative release rate of D‐limonene.

Rheology of ice cream: From fundamentals to applications

Frozen desserts, including ice cream and related products, have captivated consumer palates for centuries due to their unique combination of taste, texture, and temperature. The complex interplay between ingredients, processing techniques, and the inherent rheological behaviour of these confections has drawn the attention of scientists, engineers, and food technologists alike. Beginning with fundamental insights into the molecular interactions and phase transitions during freezing and storage, the review elucidates the evolving structure-property relationships that define the viscoelastic behaviour of frozen dessert matrices. By dissecting the role of key ingredients, additives, and processing techniques, this article provides a cohesive framework for tailoring the rheological profiles of frozen desserts to achieve desired sensory experiences and stability. Cutting-edge analytical methods, including dynamic mechanical analysis and microstructural imaging, are discussed in the context of their contributions to characterizing and predicting rheological behaviour. The review also highlights practical applications arising from this improved understanding, such as optimized manufacturing processes, enhanced quality control, and the potential to develop novel frozen dessert products with superior texture and flavour delivery. Bridging the gap between scientific insight and industrial practice, this article serves as a valuable resource for researchers, food technologists, and practitioners seeking to advance frozen dessert technology while ensuring product consistency and consumer satisfaction.

Adsorption and controlled release performances of flavor compounds by rice bran insoluble dietary fiber improved through steam explosion method

In this study, steam explosion was employed as a modification process for rice bran insoluble dietary fiber (RBIDF) to improve the flavor adsorption and controlled release capacities of RBIDF. Results showed that the flavor adsorption ability of RBIDF was effectively improved due to the unfolding structure, increased specific surface area and pore volume and exposure of more functional groups after steam explosion treatment. The mechanism of the flavor adsorption behavior of modified RBIDF was preliminarily explored using adsorption kinetics and isotherms combined with SEM and DSC analysis. Results showed that the Langmuir isotherm model and pseudo-second-order kinetic model yielded the best fit to the adsorption data, indicating monolayer adsorption of flavor onto the modified RBIDF, and the adsorption was mainly driven by chemisorption process. The flavor release profile of modified RBIDF was investigated by HS-SPME/GC-MS and E-nose. After long-time storage, the flavor compounds were retained at a higher concentration in the modified RBIDF compared with the untreated RBIDF, indicating that the steam explosion treatment prolonged the retention time and enhanced the retention and controlled release capacities of RBIDF for flavor compounds. This study provides indications for potential applications of steam explosion-modified RBIDF as a novel flavor delivery system and functional ingredient.

Using X-ray Computed Micro-Tomography To Characterize Seeds as Flavor Delivery Systems

Using X-ray Computed Micro-Tomography To Characterize Seeds as Flavor Delivery Systems

Mucoadhesion: mucin-polymer molecular interactions

Mucoadhesion, adhesion of a material to a mucous membrane or a mucus-covered surface, has been employed in drug delivery to prolong contact with adsorption sites and consequently a likely improvement of drug absorption. Mucoadhesion in the oral cavity also provides additional effects on tactile mouthfeel and extended flavor delivery, which impact consumer perception. The mechanisms behind mucoadhesion have not been well understood and there are contradictory literature results on the ranking of mucoadhesive properties of different polymers based on what in-vitro methods that are used. We herein examine the molecular interactions of different polymers with mucin from bovine submaxillary glands at pH 6.6 by using 1H NMR (Nuclear Magnetic Resonance) that provides atomically resolved information on conformational mobility of the mucin. Studying different types of polymers with different chemical structures and degrees of polymerization (DP), we can via the NMR linewidths and the signal intensities distinguish if the polymers interact with specific segments of the mucin or if they have a universal effect on the mobility of all the molecular segments of the mucin. The specific interaction sites on the mucin for positively charged polymer poly(ethyleneimine) are shown to be different from those for negatively and neutrally charged polymers. In addition, the interactions are also driven by the DP, the concentration of the polymers, and the dehydration. Deepened understanding of molecular effects of the different polymers on the mucin can therefore have strong impact on the development of mucoadhesive products in pharmaceutical and food applications. Finally, we raise awareness of the interpretation of rheological data in terms of mucoadhesion.

Creating delicious plant‐based products

Creating delicious plant‐based products

Controlled Release of Flavor Substances from Sesame-Oil-Based Oleogels Prepared Using Biological Waxes or Monoglycerides.

The flavor substances in sesame oil (SO) are volatile and unstable, which causes a decrease in the flavor characteristics and quality of SO during storage. In this study, the effect of gelation on the release of flavor substances in SO was investigated by preparing biological waxes and monoglycerides oleogels. The results showed that the release of flavor substances in SO in an open environment is in accordance with the Weibull equation kinetics. The oleogels were found to retard the release of volatiles with high saturated vapor pressures and low hydrophobic constants in SO. The release rate constant k value of 2-methylpyazine in BW oleogel is 0.0022, showing the best retention effect. In contrast, the addition of gelling agents had no significant retention effect on the release of volatiles with low saturated vapor pressures or high hydrophobic constants in SO, and even promoted the release of these compounds to some extent. This may be due to the hydrophilic structural domains formed by the self-assembly of gelling agents, which reduces the hydrophobicity of SO. This work provides a novel approach for retaining volatile compounds in flavored vegetable oils. As a new type of flavor delivery system, oleogels can realize the controlled release of volatile compounds.

Encapsulation of ginger oleoresin in co-crystallized sucrose: development, characterization and storage stability.

Ginger oleoresin was emulsified with gum acacia and encapsulated in a sucrose matrix by co-crystallization. The increased void space and surface area of sucrose provided a porous base for the incorporation of oleoresin. This co-crystallization led to modification from crystalline to irregular agglomerates, as evident from X-ray diffraction and differential scanning calorimetry. Hygroscopicity, water sorption isotherms and water activity demonstrated changes due to the change in crystallinity of sucrose. The active components such as [6]-, [8]- and [10]-gingerols and [6]-shogaol were quantified by HPLC. The encapsulation efficiency of [6]-gingerol was 45.59%. The storage kinetics at different relative humidity levels and temperatures indicated [6]-gingerol to be the most stable among the gingerols studied. A temperature of 25 °C and relative humidity of 33% proved to be the best storage conditions for the ginger flavoured sugar cubes. Thus, co-crystallization for the encapsulation of ginger oleoresin serves a dual purpose, i.e., protection and a mode of delivering a spicy flavour.

The potential for retronasally delivered olfactory stimuli to assess psychiatric conditions

Recent research has linked the ability to identify odours to parts of the brain that, when impaired, are associated with mental illness or disease. The link between impaired odour perception and some psychological disorders has led to the suggestion that standardised assessments probing smell be routinely adopted in the clinical environment. Odour tests currently on the market utilise the orthonasal route, though the retronasal route is a viable, but overlooked, alternative. In this study, a flavour delivery system has been developed which quickly dissolves in the buccal cavity, rapidly releasing flavours that reach the olfactory system by the retronasal route. We tested seven different types of retronasal flavour stimuli (peppermint, aniseed, liquorice, coffee, orange, lemon, and valeric acid) on 171 undergraduate and postgraduate university students and related perceptual measures with psychological wellbeing scores. Olfactory measures included odour identification, pleasantness, intensity, and familiarity. Psychological measures of schizotypy (SPQ-B), depression, stress and anxiety (DASS-21), and autism spectrum disorder (RAADS-R) were obtained to represent psychological wellbeing. A battery of hierarchical multiple linear regressions were run to determine the relationships between odour perception and the psychometric measures. After controlling for age and gender, significant negative associations were found between odour identification and the stress (β = −.347, p < .001), anxiety (β = −.376, p < .001), depression (β = −.318, p < .001), schizotypy (β = −.473, p < .001), and RAADS-R (β = −.285, p < .001) scales. Additionally, both overall pleasantness (β = −.203, p < .01) and intensity (β = .194, p < .05) ratings were negatively correlated to the RAADS-R. Our findings indicate that retronasal stimuli present a feasible alternative to olfactory assessment of psychological states and further reinforces evidence indicating a correlation between olfactory and psychological measures.

Water Diffusion in the Semi-Liquid State during Industrial Candy Preparation

In the domain of production of flavor delivery systems based on carbohydrate matrices, Hot Melt Extrusion (HME) is one of the processes used which implies a relatively slow water evaporation step compared to Spray Drying or other common processes. The HME process of generating liquid syrup is stable only at industrial scales. The drying kinetic associated to the syrup formation is followed by collecting the vapored water. This experiment is exploited to estimate the diffusion coefficient of liquid water in a continuously concentrating carbohydrate melt ranging from 30.4 to 10.2%w/w water content and at temperatures ranging from 100 to 116 °C. A combination of Fick, Arnold and Vogel-Tammann-Fulcher models was used to derive the viscosity of the solution, the gradient thickness at the surface of the stirred solution and the diffusion coefficient of water in the liquid under boiling conditions. It is here demonstrated that under continuous boiling conditions, the water concentration gradient depth from the surface of the solution has a dimension that is comparable to the size of the hydrated carbohydrate molecules and the diffusion coefficient of water in boiling carbohydrate solutions ranges from 5.10−9 cm.s−2 for low temperature and high water content to 10−11 cm.s−2 for high temperature and low water content.

Glutathione from recovered glucose as ingredient in antioxidant nanocapsules for triggered flavor delivery

Glucose recovered via enzymatic hydrolysis of rayon fibers was used for glutathione production by S. cerevisiae. Glutathione was used in combination with HSA and silk fibroin for ultrasound assisted nanocapsules production. Triggered release of flavor substances and antioxidant properties of the nanocapsules was demonstrated.

Effect of protein‐flavour binding on flavour delivery and protein functional properties: A special emphasis on plant‐based proteins

AbstractAs the loss of free volatile compounds in aqueous protein systems is known to greatly influence the quality, and therefore the consumer acceptability, of protein‐containing foods, examination of the ability of different proteins to react with volatile flavour compounds as well as the nature of the interaction are of great interest to flavour chemists. It is generally believed that the affinity of flavour to proteins is a multi‐factor function related to protein source, protein conformation and stereochemistry of the flavour compound. However, the nature of protein‐flavour interactions has not been explicit. Less focus has been put on plant‐based proteins in comparison to animal proteins. With an increase in the use of plant‐based proteins in food systems, this article provides a fundamental review of the impact protein‐flavour interactions on flavour retention and release with a special emphasis on plant protein materials. Flavour‐food matrix interactions have been examined with a focus on how they influence flavour perception. Current knowledge on methodologies involved in protein‐flavour binding studies, binding mechanisms and factors affecting the interaction have been discussed. The implication of protein‐flavour interaction on protein functionality specifically protein thermal gelation properties has also been considered. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Dynamic and viscoelastic interfacial behavior of β-lactoglobulin microgels of varying sizes at fluid interfaces

HypothesisMicrogel particles formed from the whey protein β-lactoglobulin are able to stabilize emulsion and foam interfaces, yet their interfacial properties have not been fully characterized. Smaller microgels are expected to adsorb to and deform at the interface more rapidly, facilitating the development of highly elastic interfaces. MethodsMicrogels were produced by thermal treatment under controlled pH conditions. Dynamic surface pressure and dilatational interfacial rheometry measurements were performed on heptane–water droplets to examine microgel interfacial adsorption and behavior. Langmuir compression and atomic force microscopy were used to examine the changes in microgel and monolayer characteristics during adsorption and equilibration. FindingsMicrogel interfacial adsorption was influenced by bulk concentration and particle size, with smaller particles adsorbing faster. Microgel-stabilized interfaces were dominantly elastic, and elasticity increased more rapidly when smaller microgels were employed as stabilizers. Interfacial compression increased surface pressure but not elasticity, possibly due to mechanical disruption of inter-particle interactions. Monolayer images showed the presence of small aggregates, suggesting that microgel structure can be disrupted at low interfacial loadings. The ability of β-lactoglobulin microgels to form highly elastic interfacial layers may enable improvements in the colloidal stability of food, pharmaceutical and cosmetic products in addition to applications in controlled release and flavor delivery systems.

Porous starch for flavor delivery in a tomato-based food application

The aim of this study was to evaluate the performance of porous starch, a newly proposed flavor carrier, in a simulated real industrial application. A liquid tomato flavor was plated onto porous starch, as well as onto maltodextrin, and also spray dried, being the latter the most common flavor encapsulation technique used by the food flavor industry. The three flavor systems were added into a tomato sauce that was subjected to sterilization and ambient storage to verify flavor resistance to sterilization and shelf life, measured by sensory and chemical analyses. The three flavor systems showed a similar flavor content after sterilization and similar behavior during shelf-life. Both sensory and chemical analyses confirmed that the polarity of the solvent used to carry the flavor molecules onto porous starch is a key factor in determining flavor retention over time.

Food‐grade bicontinuous microemulsions

AbstractMicroemulsions stabilized by sucrose esters in combination with lecithin are interesting flavour delivery systems because they allow the solubilization of very high levels of oil into an aqueous phase with relatively small amounts of surfactants. The aim of this study was to investigate microemulsions stabilized by these surfactants in order to determine the microemulsion type and the solubilizing capacity of the structures. Based on these results a good control and easy handling of the delivery systems is feasible. Pulsed Field Gradient (PFG) diffusion nuclear magnetic resonance spectroscopy revealed that at some specific ratios between both surfactants the formation of bicontinuous microemulsions takes place. In such systems, between 20% and 60% of the oil phase can be solubilized. The solubilization of lecithin in the flavour oil and the insertion of this mixture into a system containing direct micelles of sucrose ester changes the curvature of structures and allows the continuous transition from direct oil/water to bicontinuous structures to inverse water/oil microemulsions. In such inverse microemulsions up to 80% of flavour oil can be solubilized. Our investigation demonstrates that the presence of lecithin leads to an increase of the flavour oil loading, decreasing significantly the total surfactant concentration. Therefore, lecithin can be used as a tuning parameter to control the different types of microemulsions without additional hydrotropes and they can be easily adapted to different industrial applications. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Aroma encapsulation and aroma delivery by oil body suspensions derived from sunflower seeds (Helianthus annus)

Oil bodies are small discrete cell organelles that can be found within oilseeds. Oil bodies have been investigated previously as a potential technology platform for use within the food industry, offering stable, antioxidant-enriched lipid-delivery systems. In this study, the use of oil bodies as a flavour delivery agent is evaluated. Fresh aromatized oil bodies show comparable headspace flavour intensity to phospholipid-stabilized emulsions when in a static equilibrium state, and when evaluated by dynamic headspace dilution, aromatized oil bodies showed a significantly stronger potential to maintain their headspace volatile concentration, which may indicate that oil bodies would offer greater retronasal flavour delivery than current commercial systems.

Oil droplet size determination in complex flavor delivery systems by diffusion NMR spectroscopy

Droplet size distribution of flavor oils in two different solid flavor delivery systems were determined with pulsed field gradient NMR spectroscopy: yeast encapsulation system, a spray dried flavor encapsulation system based on empty yeast cells, and glassy encapsulation system, an extruded solid water soluble carbohydrate delivery system. The oil droplet sizes are limited by the yeast cell walls in the yeast encapsulation system and the size distribution is unimodal according to images from transmission electron microscopy. The droplet size determination with diffusion NMR is based on the Murday and Cotts theory of restricted diffusion of liquids in geometrical confinements. Good fits of the diffusion data could be obtained by applying a unimodal, log-normal size distribution model and average droplet sizes of about 2 μm were found that correspond approximately to the inner diameter of the yeast cells. Scanning electron microscopy images showed a multimodal droplet size distribution in the glassy extruded delivery systems. To fit the NMR data a bimodal log-normal distribution function with five independent fitting parameters was implemented that yielded consistent and robust results. The two size populations were found in the micron and sub-micron range, respectively. The method was sufficiently accurate to depict variation of droplet size distributions in glassy encapsulation systems of different formulation.

Effect of Fat Content on Flavor Delivery during Consumption: an in Vivo Model

Data from studies of the effect of fat on in vivo flavor release were modeled to generate a predictive model (R(2) = 0.71). The data included a range of values from the literature and 200 new data points giving a total data set of 345 values; of these, 310 values were used as a data set for model development, and the remaining 35 values were used as a test set for model validation. The model could be used to estimate the differences in flavor delivery for samples with two different fat contents. The hydrophobicity of the flavor compounds was represented in the model by including log P. The model may provide a tool to aid in flavor reformulation between samples with different fat contents. Sensory analysis showed that an orange flavor present in a high-fat food could be reformulated for a low-fat food, giving a more similar flavor experience than in the absence of any formulation changes.

Lateral Hydrodynamic Interactions between an Emulsion Droplet and a Flat Surface Evaluated by Frictional Force Microscopy

We introduce a lateral atomic force microscopy (AFM) method to measure the hydrodynamic drag force acting on a microscopic emulsion droplet moving parallel to a flat surface. A tetradecane oil droplet formed in an aqueous solution of sodium dodecylsulfate was attached to a V-shaped atomic force microscopy cantilever, and lateral hydrodynamic interactions between the droplet and a flat glass surface were measured using a range of scanning velocities. The droplet was positioned either far from the oscillating surface or was pressed to the surface under a constant applied load. These measurements demonstrate the feasibility of using AFM to study lateral hydrodynamic interactions and lubricity between soft matter materials relevant to a large number of applications in areas as diverse as flavor delivery in foods to the applications of emulsions or emollients in personal care products.

Aroma Formation during Thermal Food Processing: Why do Thermally Treated Foods Smell Differently?

During thermal processing of foods non-volatile precursors undergo various types of reactions leading to the unique aromas of well-accepted product such as cocoa, coffee, cereals or nuts. It is without doubt that the reaction between free amino acids and carbohydrates or their degradation products, known as the Maillard reaction, is among the most important "flavor delivery" systems in such foods. However, studies using approaches of "molecular sensory science" have shown that the majority of the Maillard-type reaction products, identified so far, do not show a contribution to the aroma of processed foods. In addition, many of the key Maillard aroma compounds, such as 4-hydroxy-2,5-dimethyl-3(2H)-furanone, the Strecker aldehydes or various pyrazines were found to be identical in many processed foods. Using several foods as examples, the lecture is intended to show that the quantitative balance of potent Maillard-type flavor compounds is a key to explain the differences in the different aroma perception of thermally processed foods. In addition, the presence of lipid degradation products and/or single "character impact odorants" transferred from the raw materials into the final products have to be considered as "modifiers" of the overall "aroma orchestra".