DESCRIPTIVE ANALYSIS OF CARBONATED REGULAR AND DIET LEMON-LIME BEVERAGES

Integrated Transcriptomic and Proteomic Analysis Identifies Novel Regulatory Genes Associated with Plant Growth Regulator-Induced Astringency in Grape Berries

Astringency influences the sensory characteristics and flavor quality of table grapes. We tested the astringency sensory attributes of berries and investigated the concentration of flavan-3-ols/proanthocyanidins (PAs) in skins after the application of the plant growth regulators CPPU and GA3 to the flowers and young berries of the "Summer Black" grape. Our results showed that CPPU and GA3 applications increase sensory astringency perception scores and flavan-3-ol/proanthocyanidin concentrations. Using integrated transcriptomic and proteomic analysis, differentially expressed transcripts and proteins associated with growth regulator treatment were identified, including those for flavonoid biosynthesis that contribute to the changes in sensory astringency levels. Transient overexpression of candidate astringency-related regulatory genes in grape leaves revealed that VvWRKY71, in combination with VvMYBPA1 and VvMYC1, could promote the biosynthesis of proanthocyanidins, while overexpression of VvNAC83 reduced the accumulation of proanthocyanidins. However, in transient promoter studies in Nicotiana benthamiana, VvWRKY71 repressed the promoter of VvMYBPA2, while VvNAC83 had no significant effect on the promoter activity of four PA-related genes, and VvMYBPA1 was shown to activate its own promoter. This study provides new insights into the molecular mechanisms of sensory astringency formation induced by plant growth regulators in grape berries.

The dynamic change of flavor characteristics in Pacific oyster (Crassostrea gigas) during depuration uncovered by mass spectrometry-based metabolomics combined with gas chromatography-ion mobility spectrometry (GC-IMS)

The flavor of Pacific oyster (Crassostrea gigas) significantly changed during the depuration process. This work aimed to explore the mechanism of flavor changes during the 72 h depuration by metabolomics combined with gas chromatography-ion mobility spectrometry (GC-IMS). The metabolomics analysis indicated that carbohydrate metabolism was more affected in the early stage of depuration, including the citrate cycle, glyoxylae and dicarboxylate metabolism, etc. After 72 h depuration, it affected mainly the metabolism of global and overview maps and nucleoside metabolism, etc. The equivalent umami concentration (EUC) value was calculated and exhibited a gradual increase following a 48 h depuration. The GC-MS results revealed that the content of furans was the highest, and the content of aldehydes, ketones, and alcohols was the lowest after 48 h depuration, while the content of aldehydes, ketones, and alcohols increased after 72 h depuration. All these results suggested the depuration period was recommended to be controlled within 48 h.

Conventional vs. Organic: Evaluation of Nutritional, Functional and Sensory Quality of Citrus limon

Organic farming is growing rapidly worldwide since it is perceived as more respectful of the environment than conventional farming. In this sense, organic agriculture is highly appreciated by consumers since consumers around the world believe that organic food has a higher content of beneficial compounds for health and consider it of higher quality. For that reason, the objective of this research was to evaluate the nutritional, sensorial, and functional quality of the 'Fino 49' lemon grafted on Citrus macrophylla in conventional and organic cultivation. Fatty acids, amino acids, total phenol, and polyphenols were quantified, antioxidant activity was measured, and sensory descriptive analysis was performed. Conventional farming led to an increase in amino acid content (641 mg L-1) and an increase in polyunsaturated fatty acids (254 mg 100 g-1) and monounsaturated fatty acids (37.61 mg 100 g-1). On the other hand, organically produced lemon fruits had better sensory profile (highlighting overall aroma (6.5), lemon odor (6.8), sourness (5.8), floral (0.6), and fresh lemon flavor (9.8)), and lower thrombogenicity index (0.15). The type of cultivation (organic and conventional) had no influence on the antioxidant activity (~1.60, ~3.08, and ~4.16 mmol Trolox L-1 for ABTS+, DPPH•, and FRAP, respectively) and polyphenols content (85.51 and 86.69 conventional and organic, respectively). However, to establish the advantages and disadvantages of different types of cultivation on lemon quality more studies are needed.

Effect of molar mass and size of non-alcoholic beer fractions and their relevance toward palate fullness intensity

Palate fullness intensity and mouthfeel descriptors are essential sensory characteristics of non-alcoholic beers (NABs). The descriptor's perception might be influenced by the molar distribution of the non-volatile matrix in cereal-based beverages like NABs. However, only limited information is available on the molar mass of different substances in NABs. This study investigated the role of weight average molar mass (M_w) and size of NABs fractions and their relation to sensory perception. Industrialized bottom-fermented NABs (n = 28) from the German market and NABs produced by different methods were used in this study. A trained sensory panel evaluated palate fullness intensity, mouthfeel, and basic taste descriptors (as additional quality parameters). Asymmetric flow field-flow fractionation was used to fractionate NABs, while M_w was determined by multi-angle light scattering and differential refractive index detectors. The NABs were fractionated into three groups containing different substances: proteins, proteins-polyphenol complexes (P-PC) and low molar mass (non-)starch polysaccharides (LN-SP), and high molar mass (non-)starch polysaccharides (HN-SP). The M_w range of proteins was 18.3-41 kDa, P-PC and LN-SP 43-122.6 kDa, and HN-SP 0.40-2.18·10³ kDa. Harmony, defined as the sweet and sour ratio, influenced the palate fullness intensity perception. In the harmonic samples (sour/sweet sensory balanced), the size of HN-SP (> 25 nm) showed a positive correlation to palate fullness intensity. The results suggest the importance of dextrins, arabinoxylan, and β-glucan in modulating the sensory characteristics of harmonic bottom-fermented NABs.

Novel oral microscope gives mechanistic insights into colloidal drivers of friction in oral biofilms

Texture and mouthfeel are central to the sensory enjoyment of food and beverages. Yet our incomplete understanding of how food boluses are transformed in the mouth limits our texture prediction ability. As well as thin film tribology, the interaction of food colloids with the oral tissue and salivary biofilms plays a key role in texture perception via mechanoreceptors in the papillae. In this study we describe the development of an oral microscope capable of quantitative characterization of the inactions of food colloids with papillae and their concurrent saliva biofilm. We also highlight how the oral microscope revealed key microstructural drivers of several topical phenomena (oral residue formation, coalescence in-mouth, grittiness of protein aggregates and finally microstructural origin of polyphenol astringency) in the domain of texture creation. The coupling of a fluorescent food grade dye with image analysis enabled specific and quantitative determination of the microstructural changes in mouth. Emulsions either underwent no aggregation, small aggregation, or extensive aggregation depending on whether their surface charge facilitated complexation with the saliva biofilm. Quite surprisingly cationic gelatin emulsions that were already aggregated with saliva in mouth underwent coalescence if subsequently exposed to tea polyphenols (EGCG). Large protein aggregates were found to aggregate with the saliva coated papillae, increasing their size tenfold and possibly explaining why there are perceived as gritty. An exciting observation was the oral microstructural changes that occurred upon exposure to tea polyphenols (EGCG). Filiform papillae shrunk, and the saliva biofilm was seen to precipitate/collapse, exposing a very rough tissue surface. These tentative early steps are the first in vivo microstructural insights into the different food oral transformations that are drivers of key texture sensation.

Comparative study of phenolic compounds reveals a positive relationship between astringency and the phenolic composition in table grape varieties

Phenolic compounds and their derivatives play a major role in the intensity and characteristics of grape (Vitis vinifera) astringency. The present study investigated the relationship between phenolic composition and astringency of six commercial table grape varieties (two of each white-, red-, and black-skinned). Qualitative and quantitative liquid chromatography-mass spectrometry analysis was used to identify the variety-specific phenolic profiles in the skins and total astringency intensity was assessed and described by a trained sensory panel. Thirty phenolic compounds were identified among the six varieties. Principal component analysis of the phenolic profiles revealed that the intensity of astringency of grape skin was positively correlated with catechin, epicatechin, epicatechin-3-O-gallate, and proanthocyanidin dimers B1, B2, and B3. A further orthogonal partial least-squares discrimination analysis of these compounds showed that catechin was the substance most strongly and positively correlated (R = 0.904) with grape skin astringency. PRACTICAL APPLICATION: This study provided a better understanding of the relationships between phenolic composition and table grape astringency and highlighted a potential metabolic marker that could be used as a predictor for the complex astringency sensory attributes of table grape berries.

Characteristic flavor of Antarctic krill (Euphausia superba) and white shrimp (Penaeus vannamei) induced by thermal treatment

For the good acceptance and preference of heated shrimp, characteristic flavor composition analysis was necessary. The sensory evaluation, electronic tongue, electronic nose, and gas chromatography-ion mobility spectrometry were employed in this study. After steaming or cooking, the sensory scores of Antarctic krill (KM) and white shrimp (PM) were significantly increased, and five basic tastes were remarkably changed by electronic tongue analysis. Free glycine level increased from 86.48 to 687.12 mg/100 g in PM after steaming, but no significant changes in KM. 5'-nucleotides in heated PM were higher than those in heated KM. In two kinds of shrimp, inorganic ions and lactic acids contents exhibited the decrease trends after cooking, and the response intensities of S4, S5, and S6 showed increase trends after steaming. Nonanal, benzaldehyde, (Z)-3-hexen-1-ol, 1-8-cineol and limonene were produced by thermal treatment. Therefore, characteristic flavor formation was related to thermal treatment.

Carbonated emotions: Consumers' sensory perception and emotional response to carbonated and still fruit juices

The global carbonated beverage market is large, and consumers like the oral irritation (ex. burning or prickling) associated with carbonated beverages. This study's first objective was to identify the effect of carbonation on consumers' liking and sensory perception of fruit juices (apple, cherry, and blueberry). The secondary aim was to evaluate consumers' emotional responses to carbonated fruit juices. The first trial asked consumers (n = 103) to use check-all-that-apply (CATA) and nine-point hedonic scales to evaluate six fruit juices (three carbonated and three non-carbonated). In the second trial, consumers (n = 107) were asked to evaluate the pictures of the same juices using the CATA variant of EsSense25 Profile® and a purchase intent scale. The consumers were also asked to identify what they like and dislike about carbonated beverages using an open-ended comment question. The first trial demonstrated that flavour significantly affected the overall liking scores but also identified that carbonation increased the overall liking of the blueberry and apple juices (p < 0.05). In the emotional response trial, the participants did not separate the samples based on carbonation, but rather separated the blueberry juices from the cherry and apple juices. The penalty lift analysis identified that when positive emotions were selected, the participants' purchase intent increased. Lastly, the consumers identified they like mouthfeel and flavour-enhancing qualities of carbonated beverages and associated them with special events. However, the participants disliked beverages that are too carbonated or flat and associated carbonated beverages with negative physical sensations and health perceptions. Overall, the flavour was more important than if the beverage was carbonated or not and purchase intent scores increased when positive emotions were perceived. Future research should investigate how emotions affect purchase intent, how participant's familiarity affects the emotions they select and evaluate how carbonation affects other beverages.

Effect of Reconstituted Broth on the Taste-Active Metabolites and Sensory Quality of Stewed and Roasted Pork-Hock

Stewed pork-hock in soy sauce (SPHSS) is a cuisine that is stewed in broth with abundant taste-active compounds. Broth plays an important role in determining the meat taste. In order to promote the comprehensive utilization of the broth we treated it by spray drying, and secondary processed it into reconstituted broth. Two new products: SPH (stewed pork-hock with reconstituted broth) and MRPH (marinated and roasted pork-hock with reconstituted broth) were processed. Their metabolome consisted of amino acids, sugars, organic acids, nucleic acids and their derivatives. PC1 and PC2 explained a total of 63.07% and 35.31% of the variation, respectively. All the metabolite levels in SPH were higher than those in SPHSS, except for histidine and phosphorylcholine. SPH kept the highest levels of total FAAs and total sugars, which corresponded to the highest score of overall taste in the three products. These results demonstrated that reconstituted broth can promote the metabolite concentration in and improve the taste of pork-hock. Compared with marinating and roasting, reconstituted broth was more suitable for stewing pork-hock. This study preliminarily explored a feasible method to comprehensively utilize the surplus broth in food processing. SPH with a shortened processing time by a reconstituted broth have potential application in the industry due to the high concentrations of taste metabolites.

1H NMR and multivariate data analysis of the differences of metabolites in five types of dry-cured hams

In order to distinguish the taste styles of dry-cured hams (Jinhua, Xuanwei, Country, Parma and Bama), we established a ¹H nuclear magnetic resonance spectroscopy method to identify metabolites. Totally, 33 charged metabolites, including amino acids, organic acids, nucleic acids and their derivatives, sugars, alkaloids and others were identified. The abundant glutamate, lysine, alanine, leucine and lactate could be the major contributors of taste. Total variables were explained by PC1 (67.7%) and PC2 (16.0%) which showed that Parma and Xuanwei styles were close to each other (similar amino acids, peptide, organic acids and alkaloids contents). Bama style showed the highest PC1 and amino acids, organic acids and alkaloids contents. Country style was located on the left-most area of PC1 (the lowest amino acids, organic acids and peptide, but the highest sugars contents). Sensory evaluation revealed that Bama ham had the highest overall taste score, followed by Jinhua, Parma, Xuanwei and American Country ham. We concluded that the proportions and combinations of taste components explained the specific taste instead of any single component. These findings provided a better understanding of different metabolomics among hams.

Sensory attributes of soft drinks and their influence on consumers' preferences

Soft drinks are beverages composed of water and other ingredients that provide specific sensorial attributes. Soft drink consumption patterns have recently been changed partially influenced by an increased availability of different types of beverages during the last few years. Consumers' preferences to choose one drink over another are influenced, not only by genetic, psychological and environmental factors, but also by the beverage's specific attributes. In fact, beverage consumption is driven by the sensations it gives. Because the main component of soft drinks is water, an increase in the intake of soft drinks might improve fluid intake and the levels of water in the body if it is regarded as an "essential nutrient".

A comparison of the flavor of green teas from around the world

BACKGROUND

Green teas can be grouped based on their flavor profiles. The country of origin appears to have a strong influence on the flavor of green tea probably because similar processing methods are widely used within each particular country and flavor is dependent, in part, on processing. The aim of this article is to determine what flavor differences exist among a wide range of green teas (n = 138) produced in various countries.

RESULTS

In this study we found that roast-processed teas were mostly responsible for brown-related flavors and steam-processed teas were responsible for green-related flavors. The prices of the green teas did not differentiate the flavors of the samples. Often highly priced green teas were grouped with low-priced green teas from the same manufacturer or country of origin according to their flavor attributes.

CONCLUSIONS

Differences in the tea plant varieties or cultivars likely affects flavors in green tea. However, those were not known for many samples in this research and more study will be needed to determine the effects of specific differences in varieties or cultivars.

Associations of volatile compounds with sensory aroma and flavor: the complex nature of flavor

Attempts to relate sensory analysis data to specific chemicals such as volatile compounds have been frequent. Often these associations are difficult to interpret or are weak in nature. Although some difficulties may relate to the methods used, the difficulties also result from the complex nature of flavor. For example, there are multiple volatiles responsible for a flavor sensation, combinations of volatiles yield different flavors than those expected from individual compounds, and the differences in perception of volatiles in different matrices. This review identifies some of the reasons sensory analysis and instrumental measurements result in poor associations and suggests issues that need to be addressed in future research for better understanding of the relationships of flavor/aroma phenomena and chemical composition.