Taste Components Research Articles

Identification of key taste components in loquat using widely targeted metabolomics

Loquats can be divided into white- and yellow-fleshed cultivars. Generally, white-fleshed cultivars taste better than yellow-fleshed cultivars. Currently, metabolic causes of differences in taste are unknown, due to the lack of a large-scale and comprehensive investigation of metabolites in loquat fruit. Here, we performed a LC-MS/MS-based widely targeted metabolome analysis on two cultivars, ‘Baiyu’ (white-fleshed) and ‘ZaozhongNo. 6’ (yellow-fleshed). A total of 536 metabolites were identified, 193 of which (including 7 carbohydrates, 12 organic acids and 8 amino acids) were different between the cultivars. Pathway enrichment analysis also identified significant differences in phenolic pathways between the cultivars. Our results suggest that taste differences between the cultivars can be explained by variations in composition and abundance of carbohydrates, organic acids, amino acids, and phenolics. This study provides new insights into the underlying metabolic causes of taste variation in loquat.

Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): a multicenter European study.

ObjectiveTo investigate the occurrence of olfactory and gustatory dysfunctions in patients with laboratory-confirmed COVID-19 infection.MethodsPatients with laboratory-confirmed COVID-19 infection were recruited from 12 European hospitals. The following epidemiological and clinical outcomes have been studied: age, sex, ethnicity, comorbidities, and general and otolaryngological symptoms. Patients completed olfactory and gustatory questionnaires based on the smell and taste component of the National Health and Nutrition Examination Survey, and the short version of the Questionnaire of Olfactory Disorders-Negative Statements (sQOD-NS).ResultsA total of 417 mild-to-moderate COVID-19 patients completed the study (263 females). The most prevalent general symptoms consisted of cough, myalgia, and loss of appetite. Face pain and nasal obstruction were the most disease-related otolaryngological symptoms. 85.6% and 88.0% of patients reported olfactory and gustatory dysfunctions, respectively. There was a significant association between both disorders (p < 0.001). Olfactory dysfunction (OD) appeared before the other symptoms in 11.8% of cases. The sQO-NS scores were significantly lower in patients with anosmia compared with normosmic or hyposmic individuals (p = 0.001). Among the 18.2% of patients without nasal obstruction or rhinorrhea, 79.7% were hyposmic or anosmic. The early olfactory recovery rate was 44.0%. Females were significantly more affected by olfactory and gustatory dysfunctions than males (p = 0.001).ConclusionOlfactory and gustatory disorders are prevalent symptoms in European COVID-19 patients, who may not have nasal symptoms. The sudden anosmia or ageusia need to be recognized by the international scientific community as important symptoms of the COVID-19 infection.Electronic supplementary materialThe online version of this article (10.1007/s00405-020-05965-1) contains supplementary material, which is available to authorized users.

NMR-based metabolomics profiling of no-added-nitrite Chinese bacon (unsmoked) during processing.

Variations in the taste quality of no-added-nitrite Chinese bacon (unsmoked) during processing were investigated using 1 H-NMR and multivariate data analysis. The results showed that 21 metabolites were dominant during processing, which involved marinating, air-drying, fermentation, and baking, including amino acids, sugars, organic acids, nucleic acids and their derivatives, and alkaloids. The contents of isoleucine, leucine, valine, alanine, acetate, glutamate, succinate, glycine, sucrose, tyrosine, and phenylalanine increased continuously throughout the process. The lactate, creatine, carnosine, betaine, taurine, hypoxanthine, and AMP contents all significantly increased after baking; the inosine content significantly increased after fermentation and then decreased; the histamine content significantly increased after air-drying and then decreased; and the histidine content decreased. Each processing treatment promoted taste formation in no-added-nitrite Chinese bacon (unsmoked), especially baking. The baking point owned relatively higher levels of metabolites and sensory evaluation compared to other treatments. Sensory evaluation revealed that the ultimate taste of Chinese bacon (unsmoked) at the end of baking tended toward umami (glutamate), sweetness (AMP), and sourness (lactate). The first and second principal components explained 74.0% and 13.4% of the variables, respectively. These findings indicated the potential of NMR-based metabolomics for assessing the taste quality of no-added-nitrite Chinese bacon (unsmoked), which could contribute to a better understanding of taste compound changes in meat products. PRACTICAL APPLICATION: Nitrite is commonly used in Chinese bacon (unsmoked), but excessive intake is not good for human health. Nitrite has been replaced with nitrite substitutes to prepare no-added-nitrite Chinese bacon (unsmoked). The metabolites of no-added-nitrite Chinese bacon (unsmoked) were detected to determine the key treatment that contributes to the formation of taste during processing. This study determined the main taste components of no-added-nitrite Chinese bacon (unsmoked) and its formation process, which provides new insight into the production and characteristics of flavor in Chinese bacon (unsmoked).

Changes in the major aroma-active compounds and taste components of Jasmine rice during storage

Despite the popularity of Jasmine rice, changes in the flavor of Jasmine rice in storage remain unclear. Herein, the major aroma-active compounds in Jasmine rice combined with odor activity values and detection frequencies analysis were discriminated. Furthermore, the major aroma-active compounds and taste components of rice stored were investigated. Results showed that seven components, namely, hexanal, octanal, nonanal, (E)-2-octenal, decanal, 1-heptanol, and 1-octanol were identified as major aroma-active compounds. Various volatiles in rice samples under different storage conditions increased at different rates, and high temperature promoted these changes. The main taste components of rice, such as soluble sugars and free amino acids, changed during storage. These changes may influence the sweet and umami tastes of stored rice. Electronic tongue was suited to classify Jasmine rice during storage and predict the values of umami and sweet amino acid, but was unsuited to predict the values of sucrose, glucose, fructose, and bitter amino acids.

Flavor Analysis of Mrps Made from Different Enzymolysis Products by Gas Chromatography-Mass Spectrometry

Beef-bone protein hydrolysates were obtained by Flavourzyme (F), Protamex (P), Flavourzyme followed by Protamex (Fp), Protamex followed by Flavourzyme (Pf), and combination of Flavourzyme and Protamex (DE). Samples without any enzymes served as the control (C). Subsequently, the six hydrolysates were subjected to Maillard reaction for further investigation of the contribution of enzymatic hydrolysis to flavor. SPME-GC-MS (gas chromatograph-mass spectrometer) was applied to analyze the volatile substances and taste components. The results showed that the content of volatile compounds detected by the 6 samples was significantly different, while there was little difference in the type of compounds.

Flavor Analysis of Mrps Made from Different Enzymolysis Products Based on Electronic Nose and Electronic Tongue

The effects of different enzymatic hydrolysis methods on the odor and taste of the Maillard reaction products of minced beef-bone protein were studied. Electronic nose and electronic tongue were applied to analyze the volatile substances and taste components. The results indicated that the Maillard reaction products (MRPs) had improved organoleptic and meaty characteristics, especially that of Pf and DE groups. Moreover, DE is the most potential treatment for producting meat flavor as it consume less energy source and improves production efficiency.

Comparison of taste components in stewed beef broth under different conditions by means of chemical analyzed.

The aims of this study were to investigate the effect of stewing process on the content of taste compounds in stewing beef broth. The amino acids, 5′‐nucleotides, and organic acids in stewing beef broth were determined by HPLC. The results showed that the contents of four 5′‐nucleotides in raw beef were significantly lower than that in stewed beef broth. The addition of spices, salt, and sucrose was beneficial to promote the release of amino acid in beef broth. The highest contents of umami, sweet amino acid, and total amino acid were 907.67, 2930.11, and 5088.76 μg/g in stewed beef broth with salt addition, and 1085.10, 3367.48, and 5595.20 μg/g with sucrose addition. The contents of those in the stewed beef optimal group (s‐b‐o) were 7008.53, 34007.67, and 49282.82 μg/g, respectively, which was far higher than that with salt addition and sucrose addition. The content of total amino acid and total organic acid was significantly higher in s‐b‐o‐o than in s‐b‐o. The proper amount of blend oil was beneficial to the release of flavor substances in stewed beef broth. The EUC value of the stewed beef blank group (s‐b‐b) was 3.50 g MSG/100 g. The addition of spices could significantly increase the EUC of stewed beef broth. The TAVs of 8 compounds were more than 1 in the sample of s‐b‐o‐o, including Asp, Glu, Pro, Ala, Val, Met, Arg, and tartaric acid. These 8 compounds contribute more to the taste of stewed beef broth.

Kemijske komponente kvalitete zrna sh2 genotipova kukuruza šećerca (Zea mays L. saccharata Sturt.) u ovisnosti o roku berbe

Kernel water (KW) and total soluble sugars (TSS) are major components of sweet corn taste, while total carotenoids (TC), total phenols (TP) and antioxidant activity (AA) contribute to its health benefits. Main objective was to determine the effect of genotype, harvest date and year on chemical components of kernel quality in shrunken (sh2) sweet corn. Nine sh2 genotypes were harvested at 3-day intervals from 20 to 32 days after pollination (DAP) over two years. Growing season significantly affected TC and TP only. Significant differences among genotypes were found for KW (75.3 - 77.4%), TTS (282.4 - 343.2 mg/g), TC (9.3 - 15.7 µg/g), TP (243.6 - 289.4 mg GEA/100 g) and AA (74.6 - 83.6 % inhibition). Effect of harvest date and genotype by harvest date interaction was significant for all traits. Compared to the 20 DAP, KW and TSS decreased, while TC, TP and AA tended to increase with later harvest dates. Based on KW, genotypes OS 5Esh and Overland extended harvest window up to 29 DAP. In contrast, optimum harvest window for genotype OS 244sh finished at 20 DAP. Extended harvest window for genotype Overland resulted in significant increase of TC (62.8%), TP (12.1%) and AA (12.4%).

Nutritional Attributes and Nonvolatile Taste Components of Medicinally Important Wild False Earthstar Mushroom, Astraeus hygrometricus (Agaricomycetes), from India.

Fruiting bodies of Astraeus hygrometricus mushroom grown wild in the forests of Jharkhand, India were investigated for their proximate nutritional composition and taste imparting nonvolatile components. Fruiting bodies contained good amount of total carbohydrates (55.76%), reducing sugars (15.98%), protein (16.02%), and dietary fiber (39.78%) but were low in fat (3.5%), ash (3.8%), and energy (159.5 kcal). Fatty acids were represented by monounsaturated C18:1n9c oleic acid (4.59%) and saturated C16:0 palmitic acid (2.63%). In vitro digestibility of protein is an indicator of its availability to human body and A. hygrometricus has 33.2% in vitro digestibility. Among the minerals found (mg/100 g), potassium (K, 1930.0) was major mineral followed by calcium (Ca, 443.0), magnesium (Mg, 434.0), sodium (Na, 155.0), iron (Fe, 127.0), manganese (Mn, 16.0), and selenium (Se, 1.60). Pro-vitamin D2 (ergosterol) was also determined to be 1.09 mg/g. Analysis of soluble sugars indicated that mannitol (11.22 mg/g) was the major sugar alcohol conferring sweetness to the fruiting bodies. Among total free amino acids (8.20 mg/g), seven essential amino acids (3.9) and eight nonessential amino acids (4.3) were detected. Leucine (0.92) and tyrosine (0.98) were the major essential and nonessential amino acids, respectively. Aspartic (0.61) and glutamic acid (0.63) were also present in AH and responsible for its MSG like taste. Thus, A. hygrometricus is a good source of free essential amino acids and selenium, which is not synthesized by humans. Meaty flavor of the fruiting body of A. hygrometricus was mainly due to umami 5'-guanosine monophosphate (2.43 mg/g). Sweet taste and meaty flavor of the mushroom were due to nonvolatile taste components including soluble sugars and polyols, MSG like aspartic and glutamic acid, and umami 5'-nucleotide. Overall A. hygrometricus proved its edibility as a tasty and nutritional food.

Effect of Aging Treatment Using the Chilled Room of a Domestic Refrigerator on the Total Number of Bacteria, Concentration of Taste Components, and Palatability of Meat

Effect of Aging Treatment Using the Chilled Room of a Domestic Refrigerator on the Total Number of Bacteria, Concentration of Taste Components, and Palatability of Meat

The Effects of Roasting Conditions on the Physical Appearance Traits and Aroma and Taste Components of Roasted Stem Tea

Roasted stem tea, the product of roasting green tea stems, has a characteristic aroma and appearance. In this study, we evaluated the effects of different roasting conditions on the physical appearance, aroma, and taste of roasted stem tea. The real-time moving paths of color parameter L*a*b* were similarly changed from yellow-green to yellow-red with roasting at 180 °C, 200 °C, and 220 °C for each second, indicating that L*a*b* can be a measurement of roasting degree. Bulk density data and scanning electron microscope images revealed that tea stem swelling was optimal under high-temperature roasting conditions. Higher roasting temperatures provide heat that penetrates deeper within the tea stems. Regarding aroma, the higher the roasting temperatures, the more pyrazine and geraniol are produced. The higher internal heat promoted higher pyrazine and geraniol production, thereby improving the aroma of the roasted stem tea. Catechins and amino acids were rapidly decreased under high-temperature roasting.

Nanocomposite-based packaging affected the taste components of white Hypsizygus marmoreus by regulating energy status

The effects of nanocomposite-based packaging material (Nano-PM) on the taste components and mitochondrial energy metabolism of postharvest white Hypsizygus marmoreus (WHM), as well as the underlying influence mechanism were investigated. The results showed that the major taste components, including succinic acid and mannitol, remained at higher level in Nano-PM. The flavor 5′-nucleotides (5′-GMP and 5′-IMP) of WHM in Nano-PM were significantly higher (p < 0.05) compared with that in the normal packaging material (Normal-PM). Principal component analysis indicated that there was a distinction of flavor compounds (6 organic acids, 3 soluble sugars and 5 5′-nucleotides) of WHM between Nano-PM and Normal PM treatments during storage. Moreover, Nano-PM delayed the mitochondrial microstructure breakdown and the reduction of ATPase activity, and it maintained a higher ATP content and higher level of energy charge. Our results demonstrated that Nano-PM could affect the taste components of postharvest WHM partially by regulating the energy metabolism.

Non-volatile taste active compounds and umami evaluation in two aquacultured pufferfish (Takifugu obscurus and Takifugu rubripes)

Takifugu is famous for its delicious taste and consumption is increasing since eating pufferfish became legal in China in 2016. Boiled and steamed T. obscurus and T. rubripes were analyzed for their taste compounds including proximate compositions, inorganic ions, free amino acids, 5′-nucleotides and organic acids. Non-volatile taste active components and umami synergistic effects were measured using taste activity values (TAV) and equivalent umami concentrations (EUC), respectively. Additionally, the relationship between EUC and sensory evaluation was also investigated. The amount of the main taste components in T. obscurus was higher than T. rubripes, and similar results were obtained during cooking, where steaming had a higher amount of taste compounds than boiling. Inosine-5′-monophosphate was the dominant taste compound (150–370 mg/100 g) and its TAV in all samples was much >1. Na+ and K+ significantly contributed to the taste of both fish. EUC values for T. obscurus were greater than T. rubripes, and the umami intensities of 100 g of both fish were equivalent to 0.50–2.65 g monosodium glutamate. Subsequently, a positive relationship was shown between the EUC values and sensory score of umami and acceptability. All results suggested that T. obscurus had higher umami taste and was more acceptable.

고추냉이 잎의 에탄올 추출물로부터 용매분획물의 이화학적 특성 및 항산화 활성

This study was conducted to investigate the physicochemical properties and antioxidant activity of the solvent fractions obtained from 80% ethanol extracts of Wasabia koreana Nakai leaves. From the ethanol extracts, hexane, chloroform, ethyl acetate, and n-butanol fractions were sequentially extracted and collected, and further used for the investigation. The highest yield was obtained in the water fraction and its pH was 4.25. The total polyphenol, total flavonoid and total pectin contents in the ethyl acetate fraction were 56.24 mgGAE/g, 97.29 mgNE/g and 108.8 mg/g, respectively. This indicated that the extraction yields of the phenolic compounds and pectin in the solvent fractions obtained from the Wasabi leaves and petiole were significantly different. Analysis of the taste components of the ethyl acetate and water fractions was carried out using an electronic tongue sensor. A negative concentration-dependent population for the ethyl acetate fraction and a positive population for the water fraction, corresponding to DF1 (83.96%) in the discriminant function analysis (DFA) plot, were confirmed from the analysis. In the ethyl acetate fraction, the IC50 values ​​of 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging activity and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid(ABTS) radical scavenging activity were 899.88 ppm and 276.63 ppm, respectively. Therefore, the ethanol extracts and fractions from Wasabia koreana Nakai leaf have low utilization, which will be beneficial for the development of high value-added products via improvement in the taste components and antioxidant activity.

Taste Modulator Influences Rare Case of Color-Gustatory Synesthesia.

We investigated the effect of a sweetness blocker on the synesthetic taste experience of a rare color-gustatory synesthete, E.C., for whom specific colors elicit unique tastes. Blocking E.C.’s sweetness receptors while the tongue was otherwise unstimulated left other taste components of the synesthesia unaltered but initially reduced her synesthetic sweetness, which suggests a peripheral modulation of the synesthetic illusion.

Research on freezing behaviour of ‘Augusta’ and ‘Simultan’ blueberry fruits grown in Romania

Preserving fruits and vegetables by freezing is one of the most important methods of keeping their quality, for a long period of time. In this research, various ways of the freezing behaviour of ‘Augusta’ and ‘Simultan’ blueberry cultivars were examined. Freezing systems used were a classical freezer, cooler, fast freezing tunnel and an experimental model (equipment) for fast freezing in a nitrogen atmosphere designed by INMA. Experiments were focused on sensory quality, and nutritional value of frozen fruits and changes in texture, taste and biochemical components namely vitamin C. In the same time a number of factors such as freezing time and rate, which have direct influence on the final quality of the frozen product have been followed and determined. The results confirmed that blueberry fruit lends itself to preservation by freezing and that a quick-freezing process is recommended. ‘Simultan’ presented better features compared to ‘Augusta’. The presented results allow establishing the freezing methods easy to use in Romania rural areas, within family farms whose technical equipment is deficient.

Yeast and its Importance to Wine Aroma - A Review

The most mysterious aspect of wine is the endless variety of flavours that stem from a complex, completely non-linear system of interactions among many hundreds of compounds. In its widest sense, wine flavour refers to the overall impression of both aroma and taste components. Aroma is usually associated with odorous, volatile compounds; the bouquet of wine refers to the more complex flavour compounds which evolve as a result of fermentation, elevage and ageing. With the exception of terpenes in the aromatic grape varieties and alkoxypyrazines in the herbaceous cultivars, perceived flavour is the result of absolute amounts and specific ratios of many of these interactive compounds, rather than being attributable to a single impact compound. Without underestimating the complexity of these interactive effects or negating the definitive role played by the accumulated secondary grape metabolites in the varietal character of wine, this review will focus mainly on the contribution of yeast fermentation to the sensorial quality of the final product. Yeast and fermentation conditions are claimed to be the most important factors influencing the flavours in wine. Both spontaneous and inoculated wine fermentations are affected by the diversity of yeasts associated with the vineyard and winery. During the primary alcoholic fermentation of sugar, the wine yeast, Saccharomyces cerevisiae, together with other indigenous non-Saccharomyces species, produce ethanol, carbon dioxide and a number of by-products. Of these yeast-derived metabolites, the alcohols, acetates and C4-C8 1tfatty acid ethyl esters are found in the highest concentration in wine. While the volatile metabolites contribute to the fermentation bouquet ubiquitous to all young wines, the production levels of these by-products are variable and yeast strain specific. Therefore, this article also highlights the importance of untapping the hidden wealth of indigenous yeast species present on grapes, and the selection and genetic development of yeast starter culture strains with improved flavour profiles. In the future, some winemakers may prefer to use mixtures of indigenous yeast species and tailored S. cerevisiae strains as starter cultures to reflect the biodiversity and stylistic distinctiveness of a given region. This will help winemakers to fullfil the consumer's demand for individual wines with intact local character and to ensure the survival of wine's most enthralling aspect - its endless variety.

Study on biochemical divergences of the meat and egg of freshwater prawns (Macrobrachium rosenbergii).

Aquaculture of freshwater prawn (Macrobrachium rosenbergii) is an important fishery sector in Asian countries. The biochemical characteristics including proximate compositions and taste components of cultured freshwater prawns were analyzed for different gender and their egg. Freshwater prawns contained moisture ranging from 77.51% to 78.37%, protein with 19.56 to 19.91%, and low levels of lipid and ash around 0.2 and 1%, respectively. The moisture and protein contents of egg samples (72.82 and 15.61%, respectively) were lower than meat samples, whereas for the lipid content, it was otherwise significantly higher than the meat samples. The male and female meat samples of freshwater prawns were rich in free amino acids (FAAs), namely 1756 to 1725 mg/100 g with arginine, proline, glycine, glutamic acid, lysine, alanine, and taurine being the predominant compounds. On the contrary, the FAA amount of egg (590 mg/100 g) was remarkably lower than meat samples. The ATP‐related compounds in freshwater prawn meat ranged from 8.26 to 8.80 μmole/g, majorly composed of adenosine diphosphate (ADP), adenosine triphosphate (ATP), adenosine monophosphate (AMP), and inosine 5’‐monophosphate (IMP). The ATP‐related values in egg sample (28.33 μmole/g) were significantly higher with IMP (18.48 μmole/g) and AMP (5.44 μmole/g) being the predominant compounds. The pH values of male and female meats were neutral, whereas this value in egg sample was acidic (6.5). Urea content in egg sample was detected at huge value (58.35 μmole/g), whereas it was not detected in meat samples. These findings have established useful information for product developers to utilize the meat and eggs of freshwater prawns. In addition, the assessment of FAAs, ATP‐related compounds, and quality index (pH and urea content) was also established to give fundamental criteria to evaluate the quality of fresh M. rosenbergii.

Difference in microbial community and taste compounds between Mucor-type and Aspergillus-type Douchi during koji-making.

Douchi has attracted people's attention because of its unique taste and rich health function. The microbes participated in the koji-making process contribute to taste compounds of Douchi. However, the majority of studies on Douchi focused on their functional components and the microbial community in single type of Douchi during koji-making so far. In the present study, the taste components of Mucor-type and Aspergillus-type Douchi were measured initially and the results showed that the amino acid and organic acid levels as well as the percentage of unsaturated fatty acids in Mucor-type Douchi were significantly higher than those in Aspergillus-type. The investigation of the microbial composition in two types of Douchi showed that Aspergillus, Candida, Meyerozyma and Lecanicillium were shared by >50% of samples during koji-making. Comparison of the microbial community between the two types of Douchi revealed that Meyerozyma and Lecanicillium were the main microbial community with significant difference during the initial stage of koji-making, while Candida was significantly different during the later stage of koji-making. When supplemented with Meyerozyma and Candida in Aspergillus-type Douchi, the level of all amino acid and organic acids as well as the percentage of unsaturated fatty acid was significant improved, which further validated the importance roles of the two microorganisms in enhancing the taste components of Douchi during koji-making. The results provide useful information on optimizing the microbial community structure of Douchi during the process of koji-making and improving the product quality.

Non-volatile taste components and amino acid profile of jengkol (Pithecellobium jiringa) seed flour after steam blanching

ABSTRACT Jengkol (Pithecellobium jiringa) is a typical plant in the tropical region of Southeast Asia that is mostly liked by indonesian people because of savory taste. Jengkol seeds having high protein and healthy effects need processing for keeping their nutrient quality. This study aims to determine the effect of steam blanching on the non-volatile taste components of jengkol seeds. The results showed that steam blanching during 5 min decreased the total content of soluble sugars from 998.10 to 903.59 ppm, organic acid from 442.80 to 362.89 ppm and 5ʹ-nucleotides from 2.92 to 2.57 mg/g dry weight. However, steam blanching could be able to increase the total content of free amino acids from 40.99 to 44.98 mg/g dry weight. The EUC (equivalent umami concentration) value in jengkol seeds also increased from 38.27 to 42.22 g MSG/100 g dry weight. The total content of amino acids also increased slightly from 9.81% to 10.08% (w/w) on jengkol seed flour after blanching treatment. Jengkol seed flour consists of hydrophobic amino acids (36.00–34.41%). The E/T value decreased from 35.54% to 33.92% but the PER (protein efficiency ratio) value increased from 2.43 to 2.63 on jengkol seed flour after steam blanching treatment. The steam blanching treatment increased the MSG-like components in jengkol seed flour and also gave the sweet taste and prevented the formation of the bitter taste. Hence, jengkol seed flour showed a high potential to serve as a functional food with a umami taste.