Fruity Odor Research Articles

Formation of Decatrienones with a Pineapple-like Aroma from 1-13C-Acetate by Cell Cultures of the Birch Polypore, Fomitopsis betulina.

During submerged cultivation, the edible basidiomycete Fomitopsis betulina (previously Piptoporus betulinus) developed a fruity odor, strongly reminding of pineapple. Olfactometric analysis showed that this impression was mainly caused by the two (5E/Z,7E,9)-decatrien-2-ones. At the time of maximum concentration on the 5th day, the (5E/5Z)-ratio was 94:6. Three hypotheses were experimentally examined to shed light onto the genesis of the uncommon volatiles: first, an indirect effect of agro-industrial side-streams, such as cabbage cuttings, supporting good growth; second, an unsaturated odd-numbered fatty acid precursor; and third, a polyketide-like pathway. In the presence of 1-13C- or 2-13C-acetate up to five acetates were incorporated into the molecular ions of the C10-body. Addition of 1-13C-pyruvate or 1-13C-lactate did not confirm an odd-numbered starter of the polyketide chain. None of the methylketones was found in pineapple or any other food before.

Evolution of volatile compounds from milk to curd during manufacturing of Mozzarella

The aim of this study was to investigate the evolution of the volatile compounds (VOC) from milk to curd during mozzarella manufacturing, in connection with the technique used for curd acidification (traditional = natural whey starter fermentation; industrial = direct acidification by citric acid addition). Overall, 40 compounds were identified from the entire set of samples, belonging to different chemical classes. All compounds detected in milk were also found in the curd, but at much higher concentration. In addition, many other compounds formed during curd production. By comparison of the samples from the 2 acidification techniques, and analysing the scientific literature to explain the source of the volatile compounds, it was found that microbial activity played a main role in VOC formation. In fact, the curd obtained by natural whey starter fermentation showed the most complex profile, whereas that of the curd obtained by direct acidification was much simpler. The most important odour-active compounds that could contribute to flavour of the curd made by traditional technology were 3-methylbutanal, ethyl acetate and 2,3-butanedione, responsible for ethereal, fruity and buttery odour. For direct acidification they were 3-methylbutanal (at lower level), nonanal and decanal (herbal/fruity odour). The PCA analysis showed clear clusterization of the three types of samples: milks and direct acidified curds were rather close in the bi-plot graph, whereas traditional curds were spread all along the space. The research is currently in progress, for assessing the evolution of the volatile compounds during the next technological steps of mozzarella manufacturing.

Preparation and odor characteristics of methylthiomethyl carboxylates

AbstractSixteen methylthiomethyl esters were prepared by the reactions of carboxylic acids with dimethyl sulfoxide and oxalyl chloride. The reactions were carried out at a low temperature by Pummerer rearrangement to produce the esters in 82‐94% yields. The odor characteristics of the esters obtained were evaluated by GC‐MS‐O and most of them possessed pleasant fruity odors.

Cytogenetic status of children in the hygienic assessment of the air pollution by odorous substances

For the first time the impact of odorous emissions from the enterprise for the production of chewing gum on the cytogenetic status of children, residing in the distance of 0,9 and 6 km, was studied. Specific weak mint and fruity odour in the air in the placement of the enterprise may be related to the presence of menthol, menthone, pinene, limonene, ethyl acetate and other compounds containing in the emissions. There were no differences in cytogenetic status of children in both groups (by frequency of micronuclei, protrusions, binucleated cells, apoptosis).

QUALITY AND AEROBIC STABILITY OF FERMENTED ROLLED CORN GRAIN IN UNDER COMBINED INTRODUCTION OF PROBIOTIC STRAINS OF LACTIC ACID BACTERIA AND REPRESENTATIVES OF BACILLUS SUBTILIS

Objective. To find out the effect of combined introduction of probiotic strains of lactic acid bac-teria and Bacillus subtilis on the quality and aerobic stability of fermented rolled corn grain. Methods. Microbiological, zootechnical. Results. According to the results of organoleptic analysis, preserved rolled corn grain of the experimental and control variants had a preserved texture with a pleasant fruity odour. Preservation of crude fibre in the raw material of the experimental variants treated with Bacillus subtilis ВРT-B1 and under the combined use of lactic acid bacteria with aero-bic bacilli was higher by 10.0 % and 3.3 %, respectively, as compared to positive control parame-ters (Subtikon grain processing). The protein content in the experimental variants and the positive control was higher by 2.4–7.2 % than in the control variant of the feed (without the use of microor-ganisms). After aerobic exposure of feed for 14 days, preservation of crude fibre in all variants be-gan to decrease, however, the greatest losses (20 %) were noted in the control variant (without in-troduction of bacteria). The highest protein losses were observed in the control variant (3.8 %).After aerobic exposure, acidity in all variants of the experiment remained in the optimal range of pH 3.9–4.2. At day 70 of feed preservation, an increase in the number of lactic acid bacteria by 2–3 orders of magnitude in samples of experimental variants and positive control in comparison with this parameter in the raw material was noted. After air access to preserved rolled corn grain for 14 days, the lowest number of lactic acid bacteria was observed in absolute control, the high-est — in the variant with the combined inoculation by strains of Lactobacillus plantarum КT-L18/1 and Bacillus subtilis ВРT-B1. No pathogenic and butyric acid bacteria were detected. Conclusi-on. The combined use of probiotic strains of lactic acid bacteria and Bacillus subtilis to preserve corn grain contributes to the preservation of nutrients, the establishment and maintenance of an op-timal level of acidity, prevents aerobic food spoilage.

Influence of rate of inclusion of microalgae on the sensory characteristics and fatty acid composition of cheese and performance of dairy cows

Modification of milk and cheese fat to contain long-chain n-3 fatty acids (FA) by feeding microalgae (ALG) to dairy cows has the potential to improve human health, but the subsequent effect on the sensory attributes of dairy products is unclear. The objective was to determine the effect of feeding dairy cows different amounts of ALG that was rich in docosahexaenoic acid (DHA) on milk and cheese FA profile, cheese sensory attributes, and cow performance. Twenty Holstein dairy cows were randomly allocated to 1 of 4 dietary treatments in a 4 × 4 row and column design, with 4 periods of 28 d, with cheddar cheese production and animal performance measurements undertaken during the final 7 d of each period. Cows were fed a basal diet that was supplemented with ALG (Schizochytrium limancinum) at 4 rates: 0 (control, C), 50 (LA), 100 (MA), or 150 g (HA) of ALG per cow per day. We found that both milk and cheese fat content of DHA increased linearly with ALG feed rate and was 0.29 g/100 g FA higher in milk and cheese from cows fed HA compared with C. Supplementation with ALG linearly reduced the content of saturated FA and the ratio of n-6:n-3 FA in milk and cheese. Supplementation with ALG altered 20 out of the 32 sensory attributes, with a linear increase in cheese air holes, nutty flavor, and dry mouth aftertaste with ALG inclusion. Creaminess of cheese decreased with ALG inclusion rate and was positively correlated with saturated FA content. We also observed a quadratic effect on fruity odor, which was highest in cheese from cows fed HA and lowest in LA, and firmness and crumbliness texture, being highest in MA and lowest in HA. Supplementation with ALG had no effect on the dry matter intake, milk yield, or live weight change of the cows, with mean values of 23.1, 38.5, and 0.34 kg/d respectively, but milk fat content decreased linearly, and energy-corrected milk yield tended to decrease linearly with rate of ALG inclusion (mean values of 39.6, 38.4, 37.1, and 35.9 g/kg, and 41.3, 41.3, 40.5, and 39.4 kg/d for C, LA, MA, and HA, respectively). We conclude that feeding ALG to high-yielding dairy cows improved milk and cheese content of DHA and altered cheese taste but not cow performance, although milk fat content reduced as inclusion rate increased.

Complementary Untargeted and Targeted Metabolomics for Differentiation of Extra Virgin Olive Oils of Different Origin of Purchase Based on Volatile and Phenolic Composition and Sensory Quality.

In order to differentiate the extra virgin olive oils (EVOO) of different origin of purchase, such as monovarietal Italian EVOO with protected denomination of origin (PDO) and commercial-blended EVOO purchased in supermarkets, a number of samples was subjected to the analysis of volatile aroma compounds by both targeted gas chromatography/mass spectrometry (GC-MS) and untargeted profiling by comprehensive two-dimensional gas chromatography/mass spectrometry (GC×GC-TOF-MS), analysis of phenols by targeted high-performance liquid chromatography/mass spectrometry (HPLC-DAD-ESI/MS), and quantitative descriptive sensory analysis. Monovarietal PDO EVOOs were characterized by notably higher amounts of positive LOX-derived C6 and C5 volatile compounds, which corresponded to the higher intensities of all the assessed positive fruity and green odor sensory attributes. Commercial-blended EVOOs had larger quantities of generally undesirable esters, alcohols, acids, and aldehydes, which coincided with the occurrence of sensory defects in many samples. Many minor volatile compounds that were identified by GC×GC-TOF-MS were found to differentiate each of the two investigated groups. The differences between the groups with respect to phenols and taste characteristics were evident, but less pronounced. The results that were obtained in this study have undoubtedly confirmed the existence of the large heterogeneity of oils that are sold declared as EVOO. It was shown that GC-MS, GC×GC-TOF-MS, and HPLC-DAD-ESI/MS analyses have complementary outputs, and that their use in combination has advantages in supporting the results of sensory analysis and objectively differentiating these groups of EVOO.

Potential of the microalgae Nannochloropsis and Tetraselmis for being used as innovative ingredients in baked goods

The potential use of the microalgae species Tetraselmis and Nannochloropsis was investigated for the production of functional breads and crackers. Optimum flour substitution levels were 2.5% for baked crackers and 1.0 or 2.0% for breads containing Nannochloropsis or Tetraselmis, respectively. No major differences were observed in the physicochemical properties of the end products besides an expected darker and greener colour. Microalgae incorporation led to increased phenolic content and in vitro antioxidant capacity in both matrices. For example, the total phenolic content of crackers increased from 24.6 ± 1.5 mg/100 g in the control to 32.4 ± 0.4 or 34.2 ± 1.0 mg/100 g in crackers containing Tetraselmis or Nannochloropsis, respectively. The amount of bioaccessible polyphenols after a simulated gastrointestinal digestion was also higher in microalgae-containing goods than in the controls. Sensory evaluation showed that microalgae-containing products were competitive with the controls with the added advantage of having an improved nutritional value and a “trendy” ingredient. Moreover, microalgae-containing products showed an increased emission of some volatile compounds such as p-cymene and (Z)-2-heptenal, which are responsible for fresh, citrus, terpenic, woody, and spicy or fatty, oily, and fruity odours, respectively.

Free and bound volatile compounds in the Rubus coreanus fruits of different ripening stages.

The aim of the present study was to investigate the free and bound volatiles in the Rubus coreanus (RC) fruits of different ripening stages. Thirty-seven free volatiles and 28 bound volatiles were identified in RC fruit for the first time. The contents of free (E)-2-hexen-1-ol, 1-hexanol, 2-heptanol, β-myrcene, (E), (Z)-β-ocimene, allo-ocimene, linalool, cosmene, α-terpineol, methyl salicylate, eugenol, and β-damascenone remain high, and increased with the ripening of RC fruit. The contents of 11 bound volatiles decreased during the ripening, and became lower than the contents of their free volatiles in the ripe fruit. The ripe black fruit is closely correlated to the free nonanal, sulcatone, (E)-2-hexen-1-ol, 1-hexanol, 2-heptanol, 1-heptanol, 1-nonanol, (E)-linalool oxide (furanoid), and β-damascenone, and bound (E)-2-hexen-1-ol and (E)- β-ocimene. The ripe RC fruit is more fruity and floral than unripe fruit. The gradually hydrolyzed bound volatiles can enhance the fruity, floral, and herbaceous odors. PRACTICAL APPLICATIONS: Rubus coreanus (RC) fruit is a functional natural fruit. Both fresh and processed Rubus coreanus fruits including jams, confitures, wine, yogurt, vinegar, and beverages, as well as ingredients in functional foods or cosmetics have been extensively consumed. However, the free and bound aroma compounds in RC fruit have not been well understood. This work illustrates the contributions of free and bound volatiles to the flavor of RC fruit.

Characterization of odour-active volatiles and sensory analyses of roasted oak (Quercus humboldtii Bonpl.) acorns, a coffee substitute

Antecedentes: las bellotas de roble se tuestan y se muelen para producir un polvo que se utiliza para preparar una bebida sustituta del café. Objetivos: Identificar los volátiles con olor activo del polvo derivado de las bellotas tostadas de Quercus humboldtii y realizar un análisis cuantitativo descriptivo (QDA) de su aspecto, olor y sabor. Métodos: Los compuestos volátiles con olor a olor de la bellota de roble tostado en polvo se extrajeron con SDE y se analizaron por GC / MS y análisis olfativos (GC / O). Los análisis sensoriales de esta bebida se realizaron por QDA (análisis cuantitativo descriptivo). Resultados:Se identificaron diecinueve compuestos que mostraban notas de olor ácido, mantecoso / caramelo, humo / tostado y afrutado, que son comunes a las del café tostado. Las cetonas, aldehídos, ácidos alifáticos, alcoholes furánicos y pirazinas se identificaron como relevantes para esta bebida sustitutiva del café. Los principales compuestos volátiles fueron furfural, 5-metilfurfural, alcohol de furfurilo y 3-hidroxi-2-butanona, algunos de ellos relacionados con la descomposición del azúcar por calentamiento. Los atributos de olor caracterizados por QDA estaban de acuerdo con los detectados por GC-O (cromatografía de gases acoplada a olfatometría), pero se detectaron algunas notas de mal sabor. Conclusiones:Los resultados del enfoque sensorial molecular confirmaron que este producto se parece al café; sin embargo, los análisis de QDA mostraron la presencia de sabor indeseable. Se necesitan más estudios para mejorar la calidad del sabor de este sustituto del café.

Volatile Organic Compound and Fatty Acid Profile of Milk from Cows and Buffaloes Fed Mycorrhizal or Nonmycorrhizal Ensiled Forage.

Seed inoculation of forage crops by arbuscular mycorrhizal fungi (AMF) generally results in higher profitability, but also modifies the chemical composition of silage in terms of increased biomass, protein, and dry matter. Raw milk aroma is affected by the type of feed. This work investigated the influence of ensiled forage obtained by seed inoculation with AMF on the volatile fractions and fatty acid composition of milk. Two experiments were carried out: in the first, buffaloes were fed maize silage, and in the second, cows were fed sorghum silage. The volatile fractions of milk were quantified by headspace solid-phase micro-extraction (HS-SPME), combined with gas chromatography–mass spectrometry (GC-MS), and fatty acids by gas chromatography (GC). The ensiled forage obtained with AMF increased saturated fatty acids (SFAs), and decreased monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) in both experiments. The volatile fraction in milk samples obtained from bovines fed mycorrhizal ensiled forage showed an increase of free fatty acids and ketones, responsible for cheesy and fruity odors. Aldehydes, responsible for green and grassy notes, increased only in the milk from buffaloes fed ensiled maize. Our results suggest that inoculation of maize and sorghum seed with AMF, combined with a low rate of fertilizers, leads to ensiled forage that could slightly affect the FA profile and odor quality of milk.

Effects of prefermentative cold soak on polyphenols and volatiles of Aglianico, Primitivo and Nero di Troia red wines.

Effectiveness of prefermentative cold soak (PCS) on polyphenols and volatiles extraction during winemaking of three red grape cultivars grown in southern Italy (Aglianico, Primitivo and Nero di Troia) was investigated. Four 200‐L stainless steel horizontal rotary wine fermenters were used. The main result was that PCS improved the extraction of polyphenols and increased the antioxidant activity of wines. Extraction of proanthocyanidins was enhanced (+25%, +14% and +7% for Aglianico, Primitivo and Nero di Troia, respectively) and, consequently, the ratio flavans reactive with vanillin/proanthocyanidin was reduced, thus potentially favoring the chromatic and tannic stabilization of wines. As regards volatiles, PCS increased ester compounds at levels above their odor thresholds, potentially conferring fruity odor to wines. In conclusion, PCS could be favorably introduced in winemaking to enhance the enological potential of Aglianico, Primitivo and Nero di Troia wines.

A 13-week subchronic toxicity study of hexyl acetate in SD rats.

Hexyl acetate (CAS No. 142-92-7) is a naturally occurring ester compound that has a fruity odor. Despite its frequent use as a nature-identical flavoring agent, there are limited repeated dose toxicity data for hexyl acetate. Here we performed a 13-week subchronic toxicity study of hexyl acetate in male and female Crl:CD(SD) rats under GLP regulations. Hexyl acetate was given orally by gavage at doses of 0, 100, 300, or 1,000 mg/kg/day using corn oil as the vehicle. No significant toxicological changes in general condition, body weights, food intake, ophthalmology, hematology, organ weights, and histopathological findings were observed in any groups. Urinalysis revealed occult blood in two male animals treated with 1,000 mg/kg/day hexyl acetate, and one showed red blood cells in the urine sediment. Furthermore, blood biochemistry showed a significant increase in inorganic phosphorus levels in males treated with 1,000 mg/kg/day hexyl acetate. These results indicated that the no-observed-adverse-effect level (NOAEL) of hexyl acetate was 300 mg/kg/day for males and more than 1,000 mg/kg/day for females.

In vitro antioxidant activity and solar protection factor of blackberry and raspberry extracts in topical formulation.

Berries are known for their antioxidant activity due to the presence of flavonoids. Antioxidants' usage guarantees skin protection against free radicals and, flavonoids, especially, can act as sunscreen. The aim of this paper was to evaluate solar protection factor (SPF) and antioxidant activity in vitro of blackberry and raspberry extracts incorporated in topical formulation and study their stability. Raspberry presented 29.93mg of anthocyanins/100g of fruit and blackberry 65.58mg of anthocyanins/100g of fruit. In vitro solar protection factor was 54.57 to blackberry and 37.32 to raspberry. When incorporated in O/W emulsions, final formulations showed light pink color, creamy aspect, and typical fruity odor. Formulations submitted to indirect light and stove showed odor and color alterations. Based on the results, formulations containing extracts should be kept under refrigeration in opaque package to ensure stability due to the presence of flavonoids. In addition, blackberry and raspberry extracts are potential natural alternatives to be used as sunscreen and to prevent skin aging.

Borage, calendula, cosmos, Johnny Jump up, and pansy flowers: volatiles, bioactive compounds, and sensory perception

The aim of the present work was to study the main volatile and bioactive compounds (monomeric anthocyanins, hydrolysable tannins, total flavonoids, and total reducing capacity) of five edible flowers: borage (Borage officinalis), calendula (Calendula arvensis), cosmos (Cosmos bipinnatus), Johnny Jump up (Viola tricolor), and pansies (Viola × wittrockiana), together with their sensory attributes. The sensory analysis (10 panelists) indicated different floral, fruity, and herbal odors and taste. From a total of 117 volatile compounds (SPME–GC–MS), esters were most abundant in borage, sesquiterpenes in calendula, and terpenes in cosmos, Johnny Jump up, and pansies. Some bioactive and volatile compounds influence the sensory perception. For example, the highest content of total monomeric anthocyanins (cosmos and pansies) was associated with the highest scores of colors intensity, while the floral and green fragrances detected in borage may be due to the presence of ethyl octanoate and 1-hexanol. Therefore, the presence of some volatiles and bioactive compounds affects the sensory perception of the flowers.

Aroma characterization of a wild plant (Sanguisorba albanica) from Kosovo using multiple headspace solid phase microextraction combined with gas chromatography-mass spectrometry-olfactometry

A wild plant (Sanguisorba albanica) from Kosovo exhibits an appealing aroma, which was perceived as intensely fresh, green, and slightly sweetish with hints of cucumber, melon, and green tea. The characteristic aroma of S. albanica was analyzed for the first time by employing advanced molecular sensory techniques coupled with multiple headspace solid phase microextraction (MHS-SPME). Thirty-six different odor impressions were perceived, and 34 corresponding compounds were identified by a gas chromatography system equipped with a mass spectrometric detector and an olfactory detection port. By aroma dilution analysis, sixteen key odorants with flavor dilution factors higher than 16 were identified. Their respective concentrations were quantified by means of MHS-SPME according to the determined β values (0.43–0.83), and odor activity values (OAVs) were calculated. (E,Z)-2,6-Nonadienal (green, melon-like, and sweetish odor; OAV 20,046), followed by linalool (floral and citrus-like odor; OAV 10,563), (Z)-6-nonenal (cucumber-like, green, and melon-like odor; OAV 4200), ethyl isobutyrate (floral and fruity odor; OAV 1315), and (E)-2-nonenal (green and fatty odor; OAV 1062) were representative odorants contributing to the overall aroma of S. albanica. Differences between stems, leaves, and flowers of S. albanica with regard to the key odorants were also presented. Intensely green and floral aromas of the leaves and flowers were greatly attributed to (E,Z)-2,6-nonadienal and linalool, respectively. Apart from these compounds, (Z)-6-nonenal contributed to the overall aroma of the stems as well.

First Report of Basal Stem Rot on Oil Palm Caused by Thielaviopsis paradoxa in Hainan, China

Oil palm (Elaeis guineensis) is one of the most widely grown and distributed oil plants in southern Asia. It is usually grown as a garden ornamental in China. A serious basal stem rot disease was observed on young oil palm (Tenera variety) during the months of October and December in 2017 in Wenchang, Hainan Provence, China, at several locations. A survey of 100 2-year-old oil palm plants revealed that the disease caused serious damage during the typhoon season of Hainan Province, with 20 to 25% incidence in plants. The leaf symptoms included wilting and necrosis, beginning with the lowest leaves in the canopy. Cross-sections revealed brown rot confined to one side of the basal stem, where the rot was spreading inward from the surface. Diseased stem tissues from six trees in two palm gardens were collected and cut into 5-mm cubes. After tissue collection, surface sterilization was performed by the immersion of the previously washed plant tissue in ethanol (75%) for 1 min and then in hypochlorite (0.1%) for 1 min; it was then rinsed with sterile distilled water and cultured on potato dextrose agar (PDA) at 25°C. A fungus was isolated from lesion margins of diseased oil palm trees. Colonies on PDA were initially white and downy, becoming black and velvety after 2 days and emitting a fruity odor. The fungus produced conidia, which were cylindrical, colorless to pale brown, and 6.1 to 13.2 × 3.4 to 5.8 μm (n = 50). Chlamydospores were terminal, in chains, obovate to oval, thick walled, brown, and 7.3 to 18.9 × 4.4 to 11.7 µm (n = 50). Conidiophores were straight, sometimes sinuous at the base, hyaline to pale brown, septated at the base, smooth, and producing a succession of conidia through the open end. The morphological characteristics and measurements of this fungal isolate matched the previous descriptions of Thielaviopsis paradoxa (De Seynes) Hohn. (Morgan-Jones 1967). For the molecular characterization, sequences of the internal transcribed spacer (ITS) regions were amplified from isolates using the primer pair ITS1/ITS4. A BLAST search of GenBank showed that the ITS (MG706124) sequences of the isolate were 99% homologous with T. paradoxa strain PG3 (GenBank accession no. KF312152). A maximum likelihood tree was generated by MEGA6.0, and isolate OPC3 clustered together with T. paradoxa strain PG3 (98% bootstrap). For a pathogenicity test, three 2-year-old healthy basal stems were wounded with a fine needle and inoculated with mycelial plugs (5-mm-diameter plugs), and another set of three basal stems were treated with pure PDA plugs as a control. All stems were placed in a growth chamber at 25°C and 90% relative humidity. The pathogenicity test was repeated three times. Two weeks after inoculation, all the inoculated rachises showed typical symptoms, and a rusty brown lesion appeared at the points of inoculation. No symptoms were observed on the controls. The fungus was reisolated from the infected tissues, fulfilling Koch’s postulates. The results obtained on morphological characteristics, pathogenicity, and molecular data corresponded with those of T. paradoxa. T. paradoxa has been reported as causing rot diseases on coconut (Yu et al. 2012), pindo palm (Tang et al. 2014), and triangle palm (Yu et al. 2016) in HaiNan. To our knowledge, this is the first report of basal stem rot of oil palm caused by T. paradoxa in China. Given its wide host range, T. paradoxa has great potential to become an economically important plant pathogen.

Orthonasal vs. retronasal: Studying how volatiles' hydrophobicity and matrix composition modulate the release of wine odorants in simulated conditions

In this study a Retronasal Aroma Simulator was employed to compare the release of volatiles from two different white wine matrices (TW: table, SW: sweet) with and without the addition of human or artificial saliva to simulate retronasal and orthonasal conditions, respectively. The headspace volatiles were isolated by Solid Phase Microextraction under dynamic conditions and identified and quantified by Gas-Chromatographic analyses.Compared to the orthonasal, the retronasal conditions modified the release of odorants from both wines and the observed trends cannot be ascribed only to dilution consequent to saliva addition. The relative amounts of volatiles belonging to different chemical classes were modified in the presence of saliva with possible sensory implications concerning some fruity (esters), oxidative (furans) and varietal (linalool, vitispirane) odorants. Regression analyses show that the impact of saliva depends on the volatile (concentration and hydrophobicity) and the non-volatile (residual sugars) composition of the wine. The highly significant linear models (TW: R2 = 0.988; SW: R2 = 0.993) indicate that the release of volatiles is logP octanol/water dependent in both the wines but the slopes change with matrix composition. This suggest that in the presence of human saliva the release of odorants with similar hydrophobicity vary as a linear function of their initial headspace concentration above the wine and is modulated by the composition of the wine matrix. Differences between artificial and human saliva confirmed that the retronasal release of wine odorants is affected by the whole salivary composition and suggest that salivary components different from mucin and α-amylase are involved in the retention of the most hydrophobic volatiles as well as in the metabolization of some aromas.

Evaluation of volatile organic compound release in modified atmosphere-packaged minced raw pork in relation to shelf-life

Abstract Volatile organic compounds (VOCs) released from fresh meat during storage have the potential to be reliable parameters for monitoring shelf-life and/or spoilage using simple sensors. The VOC release profiles in raw, minced pork packaged under modified atmosphere (70% O2, 30% CO2) stored at 4 °C were measured on days 0, 3, 6, and 12 of storage by proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS). Additional sensory and solid-phase microextraction gas chromatography mass spectrometry/olfactometry (SPME-GC–MS/O) analyses of sample subsets allowed for a comparison of VOC profile changes with changes in sensory impressions and aided compound identification. Alcohols, aldehydes, ketones and acids were observed to change over time, either increasing continuously or decreasing after reaching maximum concentrations early to mid-way during storage. Marked differences were observed in the concentrations of several compounds between the fresh (day 0) and aged samples (day 12). Sensory analyses indicated strong increases in buttery and greasy odours, moderate increases in cheesy, vomit-like, sweaty and sour-cream-like odours, and decreases in fruity odours. The number of lactic acid bacteria (LAB), Enterobacteriaceae, pseudomonads, psychrotrophs, mesophiles, yeasts and moulds increased throughout storage. Percentage wise, LAB dominated the microbial population at each sampling point and pH decreased during storage. Values of thiobarbituric acid reactive substances (TBARS) indicated marginal lipid oxidation during the first week of storage. The present study provides useful information on the development of characteristic volatile spoilage compounds and offers insights for the potential future implementation of specific sensors to monitor shelf-life.

Characteristics of aroma compounds of 11 red wines from international grape cultivars grown in Korea

The aroma compounds of 11 red wines grown and produced in Wanju region were characterized by headspace-solid phase microextraction combined with gas chromatography-mass spectrometry. Seventy-five aroma compounds were identified in the 11 red wines. The aroma compounds were grouped into five aroma series and their odor activity values were calculated to determine the aroma impact compounds in 11 wines. Alcohols, esters and C6compounds were the main contributors to the aroma in the 11 wines. Isoamyl alcohol and phenylethyl alcohol obtained from the 11 red wines contributed to the floral, sweet, and fatty odorants in the wine. Octanoic acid ethyl ester, and hexanoic acid ethyl ester contributed to the fruity, floral, and sweet odorants of all the red wines. 1-Hexanol was detected all the wines, which contributed to the green odorant. The major aroma contribution of Chanceller, Malbec, Marchel, Narsha, Pinot Meunier, and Sangiovetto wines were the fruity series. The green series was the major contribution of the Cabernet Franc, Cabernet Sauvignon, and Sauvignon Vert wines. The floral series was the major contribution of the MBA and Narsha wines. Based on the results of these studies, aroma component analysis could be used as a selection criterion for developing wine cultivars.