Odor Properties Research Articles

Physicochemical properties and aroma release of gelatin-stabilized rapeseed oil-in-water emulsions as affected by pH

The release of volatile compounds in food processing is inevitable, and controlling aroma release is an important means of improving flavor quality. Herein, the physical stability and aroma release of 50 wt% rapeseed oil-in-water emulsions stabilized by 1 wt% gelatin at various pH levels were investigated in this study. Results showed that the emulsion prepared at pH 10 had a lower creaming index (CI), a smaller droplet size, a higher zeta potential value, and greater elasticity than that prepared at pH 4 and 7. Isobutanol, dimethyl sulfide, dimethyl sulfoxide, dimethyl sulfone, and γ-butyrolactone were detected in rapeseed oil but not in all emulsions. When the aqueous phase pH increased, the ability of emulsions to bind hydrophobic compounds increased significantly, while its ability to bind hydrophilic compounds with a density greater than water or less than oil decreased. The enhancement of the aroma-retention ability was due to an increase in the binding area between hydrophobic odorants and oil droplets, while the decrease in the aroma-retention ability was due to the hydrophilic properties of odorants, thin protein films, and density difference. This work explained the flavor release mechanism from the perspective of the hydrophobicity and density of volatile compounds and the interfacial protein films, which can provide certain theoretical and practical values for improving the flavor quality of broth products.

Fibrillar assembly of whey protein isolate and gum Arabic as iron carrier for food fortification

In this study, fibrous aggregates of whey protein isolate (WPI) and gum arabic (GA) containing ferric ions were fabricated, and its fibrillation process, morphology, secondary structure, driving force, iron release in simulated gastrointestinal phase as well as its sensory properties have been investigated. The results indicated that WPI/GAFe3+ fibrils could be well formed at the mass ratio of 15: 1, concentration of 2.0 wt%, pH 3.0, heated at 90 °C for 5 h. It was observed by scanning electron microscopy and found that the nanospheric GAFe3+ was regularly entangled at the end or junction of WPI fibrils. Both circular dichroism and FTIR confirmed that secondary conformations of protein have been transformed into specific forms during the fibrilization, along with an increase of β-sheet and a decrease of α-helix. The addition of SDS disintegrating the WPI/GAFe3+ fibrils revealed the significant contribution of intermolecular hydrophobic interaction as the dominant driving forces for the formation of WPI/GAFe3+ fibrils. The iron ions release showed a significant delay in the gastric phase and followed by a rapid increase in the intestinal phase, profitable for the orally administered products with high absorption in duodenum. Moreover, the WPI/GAFe3+ fibrils exhibited higher sensory scores compared with WPI/GAFe3+ nanoparticles on the attributes of texture, color, odor and acceptance. Thus, the proposed fabrication of WPI/GAFe3+ fibrils complexes is expected to be promising for iron fortification in food industry.

Mosquito Olfactory Response Ensemble enables pattern discovery by curating a behavioral and electrophysiological response database

SummaryMany experimental studies have examined behavioral and electrophysiological responses of mosquitoes to odors. However, the differences across studies in data collection, processing, and reporting make it difficult to perform large-scale analyses combining data from multiple studies. Here we extract and standardize data for 12 mosquito species, along with Drosophila melanogaster for comparison, from over 170 studies and curate the Mosquito Olfactory Response Ensemble (MORE), publicly available at https://neuralsystems.github.io/MORE. We demonstrate the ability of MORE in generating biological insights by finding patterns across studies. Our analyses reveal that ORs are tuned to specific ranges of several physicochemical properties of odorants; the empty-neuron recording technique for measuring OR responses is more sensitive than the Xenopus oocyte technique; there are systematic differences in the behavioral preferences reported by different types of assays; and odorants tend to become less attractive or more aversive at higher concentrations.

Limonene production in microalgal photoautotrophic cultivation / Produção de limoneno em cultivo fotoautotrófico microalgal

There is a worldwide consensus in the food industry that aims to replace synthetic ingredients with natural ingredients for health promotion. The industrial relevance of microalgae as sources of extensive spectrum of bioproducts and as promising raw materials for the production of natural additives is constantly growing. Limonene, due to its proven safety, makes it widely exploitable in the food, cosmetics and pharmaceutical industries, for exhibiting vast biological activity, with beneficial effects on health. Some microalgae produce this biocompound from the isoprenoid pathway through the action of the enzyme limonene synthase (LMS) from geranyl-pyrophosphate (GPP). Therefore, the aim of the study was to investigate the formation of the volatile compound limonene, derived from six microalgae, from photoautotrophic cultivation, as well as to evaluate its odor properties. The experiment was carried out in a bioreactor with BG11 medium. The incubation conditions used were 25°C, photon flux density of 25 μmol.m-2.s-1, aeration of 1VVM (air volume per volume of medium per minute) and light cycle of 24:0h (bright:dark). Volatiles were isolated by headspace solid phase microextraction, separated by gas chromatography, identified by mass spectrometry (SPME-GC-MS) and their odor significance was evaluated based on the NIST spectrum library. Limonene was identified in the volatile fraction of the six microalgae, contributing positively to the aroma (citrus and mint), demonstrating high biotechnological capacity to obtain an alternative of this natural biocompound with commercial viability, with the microalgae Scenedesmus bijuga being the one with the greatest quantitative potential.

Microstructural, Physicochemical, Microbiological, and Organoleptic Characteristics of Sugar- and Fat-Free Ice Cream from Buffalo Milk.

Ice cream is a popular dessert product across the world. Structure, body, taste, and odor properties are created by adding non-milk ingredients and milk ingredients. The main aim of the study is to decrease the caloric value of ice cream by using sugar and fat replacements. Ice cream treatments were investigated based on microstructural, chemical, physical, microbiological, sensory, and calorific values. Four different ice creams were used (control ice cream (SC1), ice cream with stevia (SC2), ice cream with sucralose (SC3), and ice cream with sorbitol (SC4)). The chemical properties in all treatments of ice cream were significantly recorded (p < 0.05). The highest sucrose and fat levels were detected in the SC1 treatment compared with the other treatments (p < 0.05). The lowest fat and sugar amounts were observed in the SC2, SC3, and SC4 treatments (p < 0.05). The highest viscosity, overrun, and hardness values (p < 0.05) were detected in the control ice cream. Total aerobic mesophilic bacterial counts were not significantly recorded between different ice cream treatments (p < 0.05). The sensory scores were not significantly affected by sweeteners and bulk agents in the different treatments. The highest calorific value was calculated in the SC1 samples (p < 0.05). On the other hand, the lowest calorific value was calculated in SC2, followed by the SC3 and SC4 treatments. In scanning electron microscopy (SEM), the gel exhibited a homogeneous structure with a fine network within the SC2, SC3, and SC4 treatments, as it contained a cohesive structure with small-sized pores.

Análisis sensorial descriptivo de un producto no perecedero elaborado con filete de pez león (Pterois volitans L.)

The lionfish is considered an invasive species in the coasts of Yucatan and the Mexican Caribbean; therefore, it is important to develop elements that facilitate its exploitation and hunting, and promote its consumption and economic development. The objective of this study was to evaluate the sensory attributes through a descriptive analysis of a non-perishable product packaged in jars of glass, which was made from lionfish fillet. The attributes for flavor were: sweet, fish/sardine, tomato, spices, oil, for odor: fish, fish/sardine, spices, for color: beige, brown, red, and for texture: fibrous, dry, juicy, soft, firm and grainy. Similarities were found with a confidence level above 95% in the attributes of odor (fish), color (brown), flavor (sweet, fish/sardine, oil) and texture (fibrous, dry, juicy, soft, firm, granular) between the lionfish product and the commercial or reference product. The main contribution of this project is to generate an alternative for the use and sensory acceptance by consumers of a product made from this invasive species that has a great environmental impact in the region.

Characterisation of Flavour Attributes in Egg White Protein Using HS-GC-IMS Combined with E-Nose and E-Tongue: Effect of High-Voltage Cold Plasma Treatment Time.

Egg white protein (EWP) is susceptible to denaturation and coagulation when exposed to high temperatures, adversely affecting its flavour, thereby influencing consumers’ decisions. Here, we employ high-voltage cold plasma (HVCP) as a novel nonthermal technique to investigate its influence on the EWP’s flavour attributes using E-nose, E-tongue, and headspace gas-chromatography-ion-mobilisation spectrometry (HS-GC-IMS) due to their rapidness and high sensitivity in identifying flavour fingerprints in foods. The EWP was investigated at 0, 60, 120, 180, 240, and 300 s of HVCP treatment time. The results revealed that HVCP significantly influences the odour and taste attributes of the EWP across all treatments, with a more significant influence at 60 and 120 s of HVCP treatment. Principal component analyses of the E-nose and E-tongue clearly distinguish the odour and taste sensors’ responses. The HS-GC-IMS analysis identified 65 volatile compounds across the treatments. The volatile compounds’ concentrations increased as the HVCP treatment time was increased from 0 to 300 s. The significant compounds contributing to EWP characterisation include heptanal, ethylbenzene, ethanol, acetic acid, nonanal, heptacosane, 5-octadecanal, decanal, p-xylene, and octanal. Thus, this study shows that HVCP could be utilised to modify and improve the EWP flavour attributes.

Odor and Constituent Odorants of HDPE-Lignin Blends of Different Lignin Origin.

The still-rising global demand for plastics warrants the substitution of non-renewable mineral oil-based resources with natural products as a decisive step towards sustainability. Lignin is one of the most abundant natural polymers and represents an ideal but hitherto highly underutilized raw material to replace petroleum-based resources. In particular, the use of lignin composites, especially polyolefin–lignin blends, is currently on the rise. In addition to specific mechanical property requirements, a challenge of implementing these alternative polymers is their heavy odor load. This is especially relevant for lignin, which exhibits an intrinsic odor that limits its use as an ingredient in blends intended for high quality applications. The present study addressed this issue by undertaking a systematic evaluation of the odor properties and constituent odorants of commercially available lignins and related high-density polyethylene (HDPE) blends. The potent odors of the investigated samples could be attributed to the presence of 71 individual odorous constituents that originated primarily from the structurally complex lignin. The majority of them was assignable to six main substance classes: carboxylic acids, aldehydes, phenols, furan compounds, alkylated 2-cyclopenten-1-ones, and sulfur compounds. The odors were strongly related to both the lignin raw materials and the different processes of their extraction, while the production of the blends had a lower but also significant influence. Especially the investigated soda lignin with hay- and honey-like odors was highly different in its odorant composition compared to lignins resulting from the sulfurous kraft process predominantly characterized by smoky and burnt odors. These observations highlight the importance of sufficient purification of the lignin raw material and the need for odor abatement procedures during the compounding process. The molecular elucidation of the odorants causing the strong odor represents an important procedure to develop odor reduction strategies.

Sensory profile analysis of chocolate drinks using quantitative descriptive analysis (QDA)

This study aims to analyse the sensory profile of a low-fat chocolate drink. The chocolate drink is being developed in laboratory of food science and technology department at Universitas Sebelas Maret. The QDA was applied to characterize the sensory profile of the developed product (sample D) and four commercial products (sample A, B, C, and E). 13 panellists were trained to evaluate those samples based on appearance, odour, flavour, basic taste and texture. Further, ANOVA was utilized to differentiate the samples, while PCA and Spider web were applied to analyse the sensory profile of the samples. The results showed that sample D was quite similar to sample A (dominated by cocoa aroma, cocoa flavour, sandiness, undissolved particles, colour, white-cream layer, thickness texture and bitter taste), whereas sample C had similar characteristic to sample E (represented by milky aroma, milky flavour, vanilla flavour and creamy texture). Meanwhile, sample B differed from others for representing malt odour and malt flavour attributes. It is implied from the result that sample A would be the potential competitor for the developed product since they may be in the same market segmentation. Therefore, the strategy of improving the developed product should take a look at the sensory attributes of sample A as a benchmarking.

Effect of increasing tannic acid addition to the diet on milk quality in the semiarid region

The study aimed to evaluate the effect of adding tannic acid to the diet on the milk quality of cows. The five primiparous crossbred cows (Holstein x Zebu) were used, with about four years old, the average body weight of 420 ± 30 kg, 100 days of lactation initial average production of 18 ± 4 kg of milk/cow/day. The treatments consisted of increasing tannic acid (0; 1.3; 2.6; 3.9 and 5.2%) to replace corn bran in the diet, based on dry matter. The sensory attributes of odor had a significant effect (P < 0.05) of the inclusion of tannic acid in the diet. The odor attributes showed a lower average for the control treatment, and these attributes also showed orthogonal contrast, except the characteristic cow, that is, the control group differed from the treatments as the tannin was introduced, the attribute value became higher compared to the control group. The inclusion of 5.2% tannic acid in dairy cows’ diet promoted a slight variation in the taste of milk. However, it did not alter the quality or acceptance of this milk by consumers.

Insight into the evolution of aroma compounds during thermal processing of surimi gel from silver carp (Hypophthalmichthys molitrix)

This study aimed to investigate the formation of odor properties in surimi products by exploring changes in aroma compounds and their precursors at setting (40 °C) and gelling (90 °C) stages during surimi gel formation by solvent-assisted flavor evaporation, gas chromatography-mass spectrometry, and ultra performance liquid chromatography. Results revealed a gradual increase in the contents of most aldehydes, alcohols, and phenolics during surimi gel formation, while a decrease in the contents of (E)-2-pentenal, (E)-2-hexnenal, (Z)-4-heptenal, (E)-2-heptenal, and most ketones at gelling stage. During thermal process, 50 % decrease was observed in the contents of some unsaturated fatty acids (palmitoleic acid, oleic acid, etc.), and the contents of tyrosine, phenylalanine, methionine, isoleucine, and leucine decreased significantly (P < 0.05) at gelling stage. Moreover, lipoxygenase activity reached 4.19–4.81 U/min·g at setting stage. Overall, amino acid degradation and lipid auto-oxidation mainly occurred at gelling stage to promote the formation of related compounds.

Potential of teff (Eragrostis tef) flour as an ingredient in gluten‐free cakes: chemical, technological and sensory quality

SummaryThis article aimed to evaluate the chemical, technological and sensory characteristics of gluten‐free cakes made with teff (Eragrostis tef). Four cakes were evaluated: T1, 100% teff flour; T2, 75% teff flour, 12.5% rice flour, 12.5% cassava starch; T3, 50% teff flour, 25% rice flour, 25% cassava starch and T4, 25% teff flour, 37.5% rice flour, 37.5% cassava starch. Higher percentages of teff increased total ash. For apparent and specific volumes, T4 was the one with the highest mean. In sensory analysis, the attributes of appearance, colour and odour did not have significant difference among treatments. T1 received the lowest overall average for flavour (5.03). Regarding the purchase intention, the cakes did not show significant difference between T3 and T2 (3.25 and 3.08). T2, T3 and T4 obtained acceptance index higher than 70%. The use of teff flour in cakes can be promising in gluten free diet.

Sensory analysis, volatile profiles and antimicrobial properties of Origanum vulgare L. essential oils

AbstractThe present study investigated the aroma profile and antimicrobial properties of Origanum vulgare L. essential oils collected from four districts of Greece. The essential oil composition was analysed by GC/MS, and aroma attributes were determined by a panel of sensory specialists using quantitative descriptive analysis. Eighteen monoterpenes and sesquiterpenes were identified. Carvacrol, p‐cymene and γ‐terpinene were the main constituents of the essential oil extracted in wild plants grown in the islands of Samothraki and Skopelos and the mainland region of Nafpaktia. In contrast, the OEO (oregano essential oil) from Lemnos island consisted mainly of thymol, p‐cymene and γ‐terpinene. GC‐MS results concurred with the results of sensory analysis. Carvacrol and p‐cymene were associated with odour typical of oregano, while the presence of γ‐terpinene and pinene imparted minty and terpenic odour properties to oregano essential oils (OEOs). Samothraki's OEO exhibited the most prominent odour properties and was the most highly rated for oregano aroma by the sensory panel. All samples exhibited antibacterial activity against selected foodborne pathogens (E. coli, S. aureus, B. cereus and S. Typhimurium) as assayed by the well diffusion method.

Effect of glucose oxidase treatment on the aroma qualities and release of cooked off-odor components from heat-treated Hami melon juice

Melon juice produces strong cooked off-odors during heat processing, leading to serious deterioration of aroma quality. In this work, the aroma quality of melon juice, the changes in GOD reaction products, and the interactions of reaction products and cooked off-odor components were analyzed by sensory evaluation, gas chromatography–mass spectrometry/olfactory, ultraperformance liquid chromatography–triple quadrupole mass spectrometry, and isothermal titration calorimetry to study the effect mechanism of glucose oxidase (GOD) on the release of cooked off-odor components from heat-treated melon juice. The results showed that GOD treatment improved the aroma quality mainly by controlling off-odor attributes and maintaining characteristic odor attributes. This was because the reaction products (hydrogen peroxide and gluconic acid) of GOD treatment inhibited the release of cooked off-odor components from heat-treated melon juice through oxidation and hydrophobic effects. Furthermore, these products reduced the loss of characteristic odor compounds by restraining Maillard, degradation, and oxidation reactions during heat processing.

High pressure processing at ultra-low temperatures: Inactivation of foodborne bacterial pathogens and quality changes in frozen fish fillets

High pressure processing (HPP) at ultra-low temperatures was conducted against Listeria monocytogenes and Salmonella enterica in frozen pink salmon fillets. Quality changes, such as drip loss, color and odor attributes were recorded in non-inoculated pollock, pink salmon and tuna fillets. Pressures at 250 and 400 MPa were applied from 0.5 to 10 min. Reductions up to 3.5 log cfu/g were recorded for the treatments performed at −32 °C, in contrast to −50 °C where the reductions were only up to 1.5 log cfu/g. Higher pressure did not cause higher reduction. It was apparent that the main factor contributing to the bacterial inactivation is the phase transition of ice structure from I to III, in contrast to transition from I to II. Drip loss was not higher than the expected with HPP at temperatures above 0 °C, while color changes were negligible. Finally, the odor evaluation did not exhibit considerable differences between untreated and treated samples. Industrial relevanceHigh pressure processing at ultra-low temperatures is a promising treatment for bacterial inactivation and retention of quality attributes of frozen fish. Treatment at 250 MPa for only 3 min at temperatures just below −22 °C, which is feasible and affordable, caused a more than 3-log reduction against Listeria monocytogenes and Salmonella enterica, without affecting considerably the quality properties. Thus, the application of low pressure and shorter processing times gives a great potential for industrial application for frozen fish or fish that wouldn't be undesirable to freeze before pressurization.

On the production and release of Hedychium coronarium essential oil from nanoformulations

Biopolymers are usually used in encapsulation techniques to protect natural products from degradation. The essential oil of Hedychium coronarium presents a floral scent, which justifies its use in perfumes, in addition, its antimicrobial activity may contribute to its stability as natural protectant. Thus, this work aims to investigate the Hedychium coronarium essential oil extraction by steam distillation and to enhance the physicochemical stability of this essential oil through encapsulation in polycaprolactone, also preserving its odor properties. The employed nanoprecipitation process presented a 1:3 optimal polymer/oil ratio, which yielded an average particle diameter of 159 nm. The morphology was evaluated by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), the essential oil encapsulation was confirmed by thermogravimetric analysis (TGA). The formulations pH remained stable for 90 days and the controlled release of the compounds was evaluated through antioxidant activity analysis. The release and diffusion of compounds from the formulations were evaluated over time and fitted with the Peppas equation.

Odor-Based Nanomechanical Discrimination of Fuel Oils Using a Single Type of Designed Nanoparticles with Nonlinear Viscoelasticity.

Odors are one of the most diverse and complicated gaseous mixtures so that their discrimination is challenging yet attractive because of the rich information about their origin. The more similar the properties of odors are, the more difficult the discrimination becomes. The practical applications, however, often demand such discrimination, especially with a compact sensing platform. In this paper, we show that a nanomaterial designed for a specific type of odors can clearly discriminate them even with a single nanomechanical sensing channel. Fuel oils and their mixture are used as a model target that has similar chemical properties but different compositions mainly consisting of paraffinic, olefinic, naphthenic, and aromatic hydrocarbons. We demonstrate using octadecyl functionalized silica–titania nanoparticles that the difference in the compositions is successfully picked up based on their high affinity for the aliphatic hydrocarbons and alkyl chain length dependent nonlinear viscoelastic behavior. Such a properly designed material is proved to derive sufficient information from a series of analytes to discriminate them even with a single sensing element. This approach provides a guideline to prepare various sensors whose response properties are distinct and optimized depending on applications.

Influence of Yeast Strain on Odor-Active Compounds in Fiano Wine

The type of yeast strain used for wine alcoholic fermentation dramatically affects its final volatile composition and, therefore, its sensory properties. In this study, the influence of four oenological Saccharomyces strains (three S. cerevisiae and one S. bayanus) on wine volatile composition was determined on the Fiano variety, a typical cultivar from the Campania region (Italy), fermented in oak barrique. Fiano wines were analyzed by means of gas chromatography/mass spectrometry (GC/MS) and gas chromatography/olfactometry (GC/O). The results showed that the four selected yeast strains had a significant impact on the majority of volatile compounds as shown by the concentration of volatile compounds and based on the Aroma Extract Dilution Analysis (AEDA) values for many of the odor volatile compounds. This resulted in a dramatic change of the odor impact of the wines, such as the “fruity” attribute, which was higher compared to the control, and caused some changes of other odor attributes, particularly “floral”, “phenolic” and “honey”. This research demonstrates the potential of using these selected yeast strains and this technological approach of oak fermentation for this typical white wine grape variety.

Water Quality Index Analysis for Water Drinking and Irrigation in the Sumowono Groundwater Basin

The Sumowono Groundwater Basin is a cross-district basin located in Central Java Province, between Temanggung Regency, Kendal Regency, and Semarang Regency. The people in this area obtain fresh water from either dug wells or springs. The purpose of this research is to determine the feasibility of groundwater for drinking water and irrigation purposes. The method used was hydrogeological mapping and physical and chemical analysis of 10 groundwater samples. The samples were subjected to empirical testing of the Groundwater Quality Index to determine the feasibility of drinking water and irrigation using Sodium Adsorption Ratio (SAR) analysis and Wilcox diagram. The results showed that all samples physically have tasteless and odorous properties. For the chemical properties produced in the ten samples, the pH value ranges from about 6.85 - 7.27. The electrical conductivity is between 71.6 - 511 µS/cm. Total Dissolved Solids values are between 45.82 and 327.04 mg/L, with total hardness values ranging from 10 to 170 mg/L. From the results of the SAR analysis, it is found that the groundwater classes were included in S1C1 and S1C2, so that groundwater has low alkaline in both sodium and salinity, respectively. Thus, groundwater is considered suitable for consumption and irrigation purposes,

Pomological and sensory properties of 8 different fig varieties in Croatia

The common fig (Ficus carica L.) is a fruit species traditionally cultivated in coastal Croatia. After some years of being of low commercial value, the interest in fig consumption and cultivation in this region seems to start following the increasing trend. One way of promoting fig consumption is to identify the varietal sensory properties, intending to match the consumer preferences. For this reason, the goal of this study was to evaluate sensory properties and pomological characteristics of fresh fruits of five dark (‘Šaraguja’, ‘Miljska’, ‘Crnica’, ‘Piombinese’, ‘Nero Rosso’) and three light-coloured (‘Petrovača bijela’, ‘Tiger’, ‘San Martino’) skin fig varieties, grown in Croatia. Figs were harvested from 5-years old trees in the fig experimental orchard located in Istria County (Croatia). Significant differences were observed for the properties of appearance, odour, flavour, and taste. Fresh fruits of varieties 'Šaraguja' and 'Tiger' reached the highest scores for the intensity of taste, fig odour, and flavour, compared to all the others. The highest values regarding fruit thickness and width were recorded from the variety 'Petrovača bijela', lenght from the variety 'Šaraguja', while 'San Martino' variety had the fruits of biggest weight. The variety 'Miljska' displayed the lowest values in all the observed pomological parameters. The importance of the pomological description and observation of sensory parameters of fresh figs lies in permitting the producers to decide the potential of each variety based on consumer preferences.