Advancements in food science for Phenylketonuria (PKU) management: a comprehensive review.

This review systematically explores the pivotal role of food science and technology as a support for Phenylketonuria (PKU) dietary management. It delves into the genetic and metabolic underpinnings of PKU, highlighting the crucial need for stringent dietary regulation to manage phenylalanine levels and mitigate neurological complications. Through bibliometric analysis and current product evaluations, it identifies trends in PKU food research, emphasizing recent innovations in food formulations such as glycomacropeptide (GMP) supplements and higher appealing low-phenylalanine food products. Furthermore, it accentuates the sensory and consumer aspects of PKU dietary solutions, underscoring the importance of palatability for adherence. Notably, the review introduces 3D food printing as an emerging technology for creating personalized, nutrient-optimized, and sensory-appealing foods for PKU patients, offering a new horizon in dietary management. This comprehensive assessment underscores the dynamic interplay between nutritional science, food technology, and sensory evaluation in improving the quality of life for individuals with PKU.

The Sous Vide Cooking of Mediterranean Mussel (Mytilus galloprovincialis): Safety and Quality Assessment.

This study involves an investigation of the effects of various cooking temperatures, freeze-thaw processes, and food preservatives on the quality and shelf-life of sous vide Mediterranean mussels. Cooking temperatures of 80 °C or above significantly improved the microbiological quality, with bacterial counts remaining within the acceptability range for human consumption even after 21 days of refrigerated storage. Fast freezing followed by slow thawing preserved the highest moisture content, potentially improving texture. Sensory analysis revealed that refrigerated sous vide mussels maintained a comparable taste to freshly cooked samples. Frozen samples reheated via microwaving exhibited more intense flavour than pan-reheated or fresh mussels. Food additives, including citric acid, potassium benzoate, and potassium sorbate, alone or in combination with grape seed oil, significantly reduced total volatile basic nitrogen and thiobarbituric acid-reactive substances during 28 days of storage, indicating decreased spoilage and lipid oxidation. Mussels with a combination of these additives registered a nitrogen content as low as 22 mg of N/100g after 28 days, well below the limit of acceptability (<35 mg of N/100g). Food additives also inhibited bacterial growth, with mesophilic bacteria count below 3.35 Log CFU/g after 28 days, compared with 5.37 Log CFU/g in control samples. This study provides valuable insights for developing optimal cooking and preservation methods for sous vide cooked seafood, underscoring the need for further research on optimal cooking and freeze-thaw protocols for various seafood types.

The origin of mussels (Mytilus galloprovincialis): NIRS explanatory identification and the effect on consumers.

This study aimed to explore the possibility of using Near-infrared spectroscopy (NIRS) for the authentication of mussels from six different geographical areas (Campania (South-Italy), Marche (Central-Italy), Veneto (North-Italy), Greece, Ireland and Spain). Secondly, the influence of mussels origin information on liking and willingness to buy was investigated on 130 consumers (from Campania region) by conducting an online consumer test, under blind and informed conditions. NIRS- based classification method clearly identified six clusters corresponding to mussels with different origins. Also, consumers resulted strongly influenced by the origin information, preferring the familiar and local mussels compared to those from other geographic regions. Compared to methods based on chemical analysis, NIRS identification does not require reagents and is simpler, faster, more economical, and environmentally safer. Therefore, considering the importance of origin information perceived by consumers, NIRS could be a useful analytical method for mussels control to guarantee their authentication and traceability.

Application of ultrasound and microencapsulation on Limosilactobacillus reuteri DSM 17938 as a metabolic attenuation strategy for tomato juice probiotication.

Counteracting probiotic-induced physicochemical and sensory changes is a challenge in the development of probiotic beverages. The aim of the study is to apply ultrasound and microencapsulation for the attenuation of Limosilactobacillus reuteri DSM 17938 to avoid change in a probiotic tomato juice. Preliminarily, six ultrasound treatments were applied. Probiotic survival in acid environment (pH 2.5) and bile salts (1.5 g/l) after ultrasound treatment was also studied. The probiotic was inoculated in tomato juice in four forms: free cells (PRO-TJ), sonicated-free cells (US-TJ), untreated-microencapsulated (PRO-MC-TJ) and sonicated-microencapsulated cells (US-MC-TJ). Probiotic viability and pH were monitored during 28 days of storage at 4 and 20 °C. Sensory analysis was performed for PRO-TJ and US-MC-TJ sample (4 °C). Ultrasound (57 W for 6 min) did not affect cell survival and transitorily modulated probiotic acidifying capacity; it reduced probiotic survival in acidic environment but increased probiotic survival in bile salts solution. Ultrasound was effective in maintain pH value of tomato juice but only at 4 °C. Instead, microencapsulation with sodium-alginate leads to a more stable probiotic juice, particularly at 20 °C. Finally, probiotication slightly modified some sensory attributes of the juice. This study shows the potential of ultrasound and microencapsulation as attenuation strategies and highlights the need for process optimization to increase ultrasound efficacy.

Factors affecting consumer choice of novel non-thermally processed fruit and vegetables products: Evidence from a 4-country study in Europe.

A wide variety of novel non-thermal processing technologies (NTPTs) are under development to meet the increasing consumer demand for high-quality fruit and vegetable (F&V) products. Understanding consumers' needs and possible barriers to acceptance of these technologies is however essential to assess the commercial feasibility of mildly processed F&Vs. Situated within this context, and extending previous work on the topic, in this paper we present results from a large-scale choice-based conjoint analysis consumer survey to investigate consumers' choice behavior towards NTPT-processed F&V products in four European countries - Denmark, Italy, Serbia, and Spain, using three model products - orange juice, iceberg salad, and cherry tomatoes respectively processed via three NTPT - mild processing, novel washing, and active packaging, compared to three conventional processing techniques - pasteurization, conventional washing, and conventional packaging, respectively. Images of the three product categories were developed to systematically vary in three key attributes: stated benefits (health and nutrition, natural taste, shelf-life), information on processing (conventional, NTPT), and price point (reference, premium price). The results showed that, out of the three attributes considered, "stated benefit" was the most important driver of consumer choice - in all countries and across product categories. Benefits relevant to health and nutrition, and to natural taste were more positively received, compared to extension of shelf-life. Information on processing and price levels had a similar influence on consumer choice of iceberg salad and cherry tomatoes, whilst for orange juice processing had a larger effect than price, suggesting that information on processing may be more impactful for F&V-derived products than for fresh produce. Individual differences among consumers according to country, age, gender, and dietary status, appeared small and transient. The most consequential individual characteristic was consumers' level of food technology neophobia (FTN), with results showing that high FTN consumers (17% of the sample) were less likely to choose F&V treated with NTPT, compared to consumers with medium or low FTN. Overall, this research suggests that products treated with NTPT may have a broad appeal across European consumers, and that targeted communication explicitly and efficiently focusing on health and taste benefits has the greatest chance to meet consumer preferences.

Food Neophobia, Odor and Taste Sensitivity, and Overall Flavor Perception in Food.

Smell, which allows us to gather information about the hedonic value of an odor, is affected by many factors. This study aimed to assess the relationship among individual factors, odor sensitivity, and enjoyment, and to evaluate how overall flavor perception and liking in actual food samples are affected by odor sensitivity. A total of 749 subjects, from four different Italian regions, participated in the study. The olfactory capabilities test on four odors (anise, banana, mint, and pine), as well as PROP (6-n-prpyl-2-thiouracil) status and food neophobia were assessed. The subjects were clustered into three groups of odor sensitivity, based on the perceived intensity of anise. The liking and intensity of the overall flavor were evaluated for four chocolate puddings with increasing sweetness (C1, C2, C3, and C4). The individual variables significantly affected the perceived intensity and liking of the odors. Even if all of the odor sensitivity groups perceived the more intensely flavored samples as the C1 and C4 chocolate puddings, the high-sensitivity group scored the global flavor of all of the samples as more intense than the low-sensitivity group. The low-sensitive subjects evaluated the liking of the sweeter samples with higher scores than the moderate-sensitive subjects, whereas the high-sensitive subjects gave intermediate scores. In conclusion, odor sensitivity plays a pivotal role in the perception and liking of real food products; this has to be taken into account in the formulation of new products, suitable for particular categories with reduced olfactory abilities.

Is it still still water? Relationships between sparkling sensitivity and consumption frequency of carbonated waters.

Little is known about how sensitivity to trigeminal stimulation such as carbonation is affected by consumption habits and consumer characteristics. The aim of this study was to determine how detection thresholds for and perception of sparkling sensations in carbonated mineral water are affected by frequency of consumption of carbonated water and individual consumer characteristics. One hundred subjects differing in sparkling water consumption frequency (non-consumers, infrequent consumers, frequent consumers) participated. First, sparkling sensation detection thresholds were determined using the method of best estimate threshold (BET) with CO2 concentrations ranging from 0.03 to 1.05 g/L. Secondly, intensity of sparkling sensation and liking of five sparkling waters (CO2 concentrations ranging from 0.21 to 4.92 g/L) were assessed. To characterize consumers, consumption frequency of sparkling water, sensitivity to 6-n-propylthiouracil (PROP taster status) and consumer characteristics were determined. Average detection threshold of sparkling sensation (BET) was 0.44 g/L CO2 concentration. BET of sparkling sensation was not affected by consumption frequency of sparkling water and was not related to PROP taster status and consumer characteristics. Perception of sparkling intensity and liking of carbonated mineral water were significantly affected by consumption frequency of sparkling water. Sparkling sensations were perceived significantly more intensive by non-consumers compared to infrequent and frequent consumers. Surprisingly, non-consumers liked sparkling water significantly more than infrequent or frequent consumers. We conclude that consumption frequency of and preferences for carbonated water do not influence detection thresholds of sparkling sensations but influence suprathreshold intensity perception of sparkling sensations in carbonated water.

Oral Sensitivity to Flowability and Food Neophobia Drive Food Preferences and Choice.

The study aimed to investigate the role of sensitivity to flowability on food liking and choice, the relationship between sensitivity to flowability and food neophobia, and its role in food liking. Five chocolate creams were prepared with different levels of flowability, and rheological measurements were performed to characterise them. One hundred seventy-six subjects filled in the Food Neophobia Scale and a food choice questionnaire (FCq). The FCq was developed to evaluate preferences within a pair of food items similar in flavour but different in texture. Secondly, the subjects evaluated their liking for creams (labelled affective magnitude (LAM) scale) and the flowability intensity (generalised labelled magnitude (gLM) scale). The subjects were clustered into three groups of sensitivity and two groups of choice preference. The effect of individual flowability sensitivity on food choice was investigated. Finally, the subjects were clustered into two groups according to their food neophobia level. The sensitivity to flowability significantly affected the liking of chocolate creams and the solid food choice. The liking of chocolate creams was also affected by the individual level of neophobia (p = 0.01), which, in turn, was not correlated to flowability sensitivity. These results confirm that texture sensitivity and food neophobia affect what a person likes and drives what a person chooses to eat.

Phenol-Rich Food Acceptability: The Influence of Variations in Sweetness Optima and Sensory-Liking Patterns.

The consumption of phenol-rich foods is limited by their prominent bitterness and astringency. This issue has been addressed by adding sweet tastes, which suppress bitterness, but this is not a complete solution since individuals also differ in their preference for sweetness. In this study, we aimed at identifying groups of consumers differing in sweetness optima and sensory-liking patterns. To this end, increasing concentrations of sucrose were added to a chocolate pudding base. This allowed us to (1) investigate if individual differences in sensory responses are associated with different sweet liking optima in a product context, (2) define the psychological and oro-sensory profile of sweet liker phenotypes derived using a product context, and (3) assess if individuals differing in sweet liking optima differ also in consumption and liking of phenol-rich foods and beverages as a function of their sensory properties (e.g., sweeter vs. more bitter and astringent products). Individuals (1208; 58.4% women, 18-69 years) were characterised for demographics, responsiveness to 6-n-propylthiouracil (PROP), personality traits and attitudes toward foods. Three clusters were identified based on correlations between sensory responses (sweetness, bitterness and astringency) and liking of the samples: liking was positively related to sweetness and negatively to bitterness and astringency in High and Moderate Sweet Likers, and the opposite in Inverted U-Shaped. Differences between clusters were found in age, gender and personality. Furthermore, the Inverted-U Shaped cluster was found to have overall healthier food behaviours and preferences, with higher liking and consumption of phenol-rich vegetables and beverages without added sugar. These findings point out the importance of identifying the individual sensory-liking patterns in order to develop more effective strategies to promote the acceptability of healthy phenol-rich foods.

European Consumers' Perceptions and Attitudes towards Non-Thermally Processed Fruit and Vegetable Products.

In order to meet the demand for high-quality fruit and vegetable (F&V) products, a wide variety of novel non-thermal processing (NTP) technologies are under development. This study used a qualitative focus group approach to investigate consumers' perception and attitudes towards non-thermally processed F&V products among young (18-30 years old) and middle-aged (45-60 y.o.) consumers across six European countries: Denmark, Germany, Italy, Serbia, Spain, and the Netherlands. Findings show that the expected benefits and social concerns are important factors which affect consumers' attitudes toward non-thermally processed F&V. Extending shelf-life, being healthier and more nutritious, and better hygiene and safety were important benefits, whilst impacts on product quality, safety risks, higher price and environmental costs were the concerns most often mentioned by participants. However, due to a lack of knowledge and trustworthy information sources, consumers have difficulties in assessing relevant benefits and risks. Targeted communication that could explicitly and efficiently reveal benefits and risks is highly recommended to enhance consumer awareness and trust. This may especially be needed to reach middle-aged consumers who showed less confidence in NTP, compared to young consumers. Consumers from Spain, Denmark, and the Netherlands appeared more interested in consuming NTP F&V, compared to Italy, Serbia, and Germany. These findings are expected to provide recommendations to better communicate non-thermally processed F&V with consumers in the EU.

Pungency perception and liking for pasta filata cheeses in consumers from different Italian regions.

We aimed to investigate whether the sensitivity to capsaicin had an effect on pungency perception of pasta filata cheeses. In addition, we assessed the effect of several individual variables (gender, age, consumer provenance, PROP status and personality traits) on both consumer liking and choice for pasta filata cheeses. Four pasta filata cheeses at two ripening times and 272 subjects from three different Italian locations were used. Based on sensory data, the PCA discriminated sweet (ripened at 2 months) from pungent cheeses (ripened at 12 months). Cheese pungency perception increased with increasing sensitivity to capsaicin (P < 0.001). There was no clear relationship between sensitivity to capsaicin or sensitivity to cheese pungency with cheese liking, whereas a number of other aspects, including sensory attributes and individual consumer characteristics, such as consumer provenance (P < 0.001), gender (P < 0.001) and food neophobia (P < 0.05), affected the liking for different pasta filata cheeses. Consumers who were younger (18-30 y.o.; P < 0.05), female (P < 0.001), unfamiliar with pungent foods (P < 0.0001) and consumers from Potenza (P = 0.001) more often declared to prefer sweet over pungent cheese, whereas in terms of real choice supertasters and neophobic subjects chose the sweet option more often (P = 0.01). In conclusion, sensitivity to capsaicin affected pungency perception in pasta filata cheese, whereas no clear relationship was observed between pungency perception and liking. The contribution of cheese and consumer characteristics on cheese liking and choice in addition to pungency, was confirmed by the differences in declared and real choice for sweet or pungent cheeses.

Gender, Age, Geographical Area, Food Neophobia and Their Relationships with the Adherence to the Mediterranean Diet: New Insights from a Large Population Cross-Sectional Study.

The Mediterranean diet (MD) is associated with many health benefits. The association between the MD and food neophobia (FN) is still unexplored in adults. The present cross-sectional study was aimed to explore the relationships between adherence to the MD, FN, and sociodemographic variables in a large Italian cohort. Familiarity and frequency use (FFI) of prototypical and non-prototypical Mediterranean foods were used to calculate a new adherence index: the Italian Taste Mediterranean Index (ITMI). The FFI of all Mediterranean foods increased with age, while butter, soft drinks, red/cured meat, and sweets were more common in younger people. Accordingly, ITMI increased with age (F2,2384 = 54.11; p < 0.0001). Women recorded a higher ITMI (6.70) than men (6.10). Individuals with high FN showed higher FFI for soft drinks and sweets and lower ones for most typical MD foods, than individuals with low FNs. A decrease of ITMI was recorded with the increase of the FN(F2,2384 = 22.84; p < 0.0001). With ageing, ITMI increased even in individuals with a high FN. The results suggest that FN may negatively affect adherence to the MD, lowering its potential health benefits, in the adult population. Monitoring of food habits, dietary education, and anxiety management, may be valuable tools to control FN and support the adherence to the MD.

How sensory sensitivity to graininess could be measured?

Considering the lack of the literature and the need for developing a valid method to measure the texture sensitivity, in this study, we investigated the individual sensitivity to discriminate among different levels of graininess. With this purpose, five samples of cocoa-based creams were prepared, by changing the refining time. Samples were first characterized in terms of particles size distribution, by means of laser diffraction. Then, 59 subjects evaluated the cream sample graininess intensity, by using gLM scales, and their liking, by using LAM scales. The graininess scores of each subject were fitted with a power model, already observed with the instrumental results, estimating both the power law exponent and the R2 coefficient, and using them as clustering parameters. Subjects were then clustered into three groups: high sensitivity; moderate sensitivity; low sensitivity. First, as it was hypothesized, results showed a significant difference between the three groups in terms of perceived graininess. Second, even though results showed a significant difference between the three groups in terms of perceived graininess, only little differences were found in terms of liking scores. Indeed, all the samples were equally liked for both the moderate and low sensitivity groups, whereas a significant trend was observed for the highly sensitive subjects who liked more the most refined samples. No significant relationships were found with age, and only a little trend was observed with gender: females seemed to be more sensitive than males. Texture attributes discrimination ability, as for example sensitivity to graininess, could affect food rejection or preferences and choice, but it is poorly investigated. This exploratory study, proposes a method to cluster consumers, based on their sensitivity. A statistical methodology has been developed to discriminate among consumer sensitivity levels. The results provide useful information about graininess sensitivity suggesting that the used methodologies could be applied to other texture properties resulting in a valid tool for the industry in the development and optimization of tailored new products.

Influences of Psychological Traits and PROP Taster Status on Familiarity with and Choice of Phenol-Rich Foods and Beverages.

Plant phenolics are powerful antioxidants and free radical scavengers that can contribute to the healthy functional properties of plant-based food and beverages. Thus, dietary behaviours rich in plant-based food and beverages are encouraged. However, it is well-known that the bitter taste and other low-appealing sensory properties that characterize vegetables and some other plant-based foods act as an innate barrier for their acceptance. The aim of this study was to investigate the influence of psychological traits and PROP status (the responsiveness to bitter taste of 6-n- propylthiouracil) on the choice of and familiarity with phenol-rich vegetables and beverages varying in recalled level of bitterness and astringency. Study 1 aimed at assessing the variations of the sensory properties of vegetable and coffee/tea items with two check-all-that-apply (CATA) questionnaires (n = 201 and n = 188 individuals, respectively). Study 2 aimed at investigating how sensitivity to punishment, to reward, and to disgust, food neophobia, private body consciousness, alexithymia, and PROP responsiveness affect choice and familiarity with phenol-rich foods (n = 1200 individuals). A Choice Index was calculated for vegetables (CV) and coffee/tea (CC) as a mean of the choices of the more bitter/astringent option of the pairs and four Familiarity Indices were computed for vegetables (FV) and coffee/tea (FC), higher (+) or lower (-) in bitterness and astringency. Subjects higher in food neophobia, sensitivity to punishment or sensitivity to disgust reported significantly lower choice indices than individuals lower in these traits, meaning that they systematically opted for the least bitter/astringent option within the pairs. Familiarity with vegetables was lower in individuals high in sensitivity to punishment, in food neophobia and in alexithymia, irrespective of their sensory properties. The Familiarity Index with coffee/tea characterized by higher bitterness and astringency was lower in individuals high in food neophobia, sensitivity to disgust, and alexithymia. No significant effect of PROP was found on any indices. The proposed approach based on product grouping according to differences in bitterness and astringency allowed the investigation of the role of individual differences in chemosensory perception and of psychological traits as modulators of phenol-rich foods preference and consumption.

Individual Variation in PROP Status, Fungiform Papillae Density, and Responsiveness to Taste Stimuli in a Large Population Sample.

Despite considerable research investigating the role of 6-n-propylthiouracil bitterness perception and variation of fungiform papillae density in food perception, this relationship remains controversial as well as the association between the 2 phenotypes. Data from 1119 subjects (38.6% male; 18-60 years) enrolled in the Italian Taste project were analyzed. Responsiveness to the bitterness of 6-n-propylthiouracil was assessed on the general Labeled Magnitude Scale. Fungiform papillae density was determined from manual counting on digital images of the tongue. Solutions of tastes, astringent, and pungent sensations were prepared to be moderate/strong on a general Labeled Magnitude Scale. Four foods had tastants added to produce 4 variations in target sensations from weak to strong (pear juice: citric acid, sourness; chocolate pudding: sucrose, sweetness; bean purée: sodium chloride, saltiness; and tomato juice: capsaicin, pungency). Women gave ratings to 6-n-propylthiouracil and showed fungiform papillae density that was significantly higher than men. Both phenotype markers significantly decreased with age. No significant correlations were found between 6-n-propylthiouracil ratings and fungiform papillae density. Fungiform papillae density variation does not affect perceived intensity of solutions. Responsiveness to 6-n-propylthiouracil positively correlated to perceived intensity of most stimuli in solution. A significant effect of fungiform papillae density on perceived intensity of target sensation in foods was found in a few cases. Responsiveness to 6-n-propylthiouracil positively affected all taste intensities in subjects with low fungiform papillae density whereas there were no significant effects of 6-n-propylthiouracil in those with high fungiform papillae density. These data highlight a complex interplay between 6-n-propylthiouracil status and fungiform papillae density and the need of a critical reconsideration of their role in food perception and acceptability.

Salivary endocannabinoids and N-acylethanolamines upon mastication of a semisolid food: implications in fat taste, appetite and food liking.

This study aimed to evaluate whether salivary endocannabinoid (EC) and N-acylethanolamine (NAE) concentrations upon mastication of a semisolid food were involved in the sensory perception of fat taste, food liking and appetite in humans. A fat-enriched (FEP) and a low-fat control (CP) pudding were developed and used in a randomized cross-over study with 19 healthy volunteers. The study protocol combined a Modified Sham-Feeding (MSF) with a multiple-spoon Temporal Dominance of Sensations method. Subjects masticated and expectorated 10 spoons of the pudding and selected the dominant sensations among a list of attributes. Saliva samples, appetite and food liking scores were collected at baseline, immediately after the MSF of the pudding and every 5 min until 20 min after MSF. Salivary concentrations of all monitored ECs and NAEs increased during pudding mastication compared to baseline (except for palmitoylethanolamide with FEP). The raise was lower with FEP than with CP for all compounds except for 2-arachidonoylglycerol whose increase was higher than the other compounds and independent of pudding type. Salivary N-arachidonoylethanolamine, linoleoylethanolamide and palmitoylethanolamide were significantly lower at 10 and 20 min after MSF of FEP than CP. Fatty taste at the 2nd spoon and creaminess at the 5th spoon were perceived as dominant with FEP whereas only wateriness was dominant with CP at the 2nd spoon. No difference between puddings for individual appetite or food liking over the 20 min of the protocol was recorded. During mastication of a semisolid fat-enriched food, the fatty taste and the creaminess were perceived as dominant. Salivary ECs and NAEs were not associated with the individual perception of fatty taste, pudding liking and appetite sensations.

Rheological and sensory performance of a protein-based sweetener (MNEI), sucrose, and aspartame in yogurt.

Sweeteners and flavors are generally added to yogurt to make them more palatable. However, the addition of these ingredients may affect the fermentation process of yogurt as well as its physical and sensory characteristics. Consumers prioritize yogurt products that are "natural." A modified single-chain form of the natural sweet protein monellin extracted from the fruit of Dioscoreophyllum cumminsii, called MNEI, could be a useful alternative to artificial sweeteners. The aim of the present work was to evaluate new rapid sensory methods in combination with rheology to assess the viability of using MNEI to develop sweetened yogurts without the calories of sugar. We studied the gelation and cooling kinetics of 4 yogurt samples (unsweetened or sweetened with MNEI, aspartame, or sucrose) by using a rheometer. Furthermore, the 4 yogurts, with and without addition of a flavoring agent, were characterized from a sensory perspective using a combination of 2 rapid sensory methods, ultra flash profile and flash profile. Rheological results showed that, when added at typical usage levels, aspartame, sucrose, and MNEI did not generally affect the yogurt fermentation process or its rheological properties. Sensory results demonstrated that texture attributes of yogurts with aspartame and sucrose were strongly linked to sweetness and flavor perception, but this was not true for MNEI-sweetened yogurts. In contrast to results obtained from samples sweetened with sucrose and aspartame, MNEI protein did not sweeten the yogurt when added before fermentation. This study highlights the enhancing effect of flavor on sweetness perception, supporting previous reports that noted synergistic effects between sucrose or aspartame and flavors. Hence, future studies should be conducted to determine how sweet proteins behave in yogurt when added after fermentation.

A preliminary study on the application of natural sweet proteins in agar-based gels.

Natural sweet proteins may be used as sugar replacer in simple liquid food systems but their applicability in more complex matrices has not been investigated yet. Gelling agent nature and texture characteristics as well as type and distribution of a stimulus in a gel could affect taste perception through inhibition or enhancement of tastants migration to the receptors. The mechanical, nonoral texture and time-intensity sweetness characteristics of sweet proteins MNEI and super sweet Y65R mutant, aspartame and saccharin added at a concentration iso-sweet to 40 g/L of sucrose in three agar gel concentrations (1%, 1.5%, and 2%) were evaluated. The results have shown that agar concentration and agar sweetener interaction particularly affect mechanical fracture stress and non oral hardness of the sweetened gels. Time intensity results illustrated that unlike in solution, the intensity of sweet taste in a gelled system over time decreases. Indeed, the behavior of the sweet proteins differed greatly in the gelled system compared to when they are in solution. PRACTICAL APPLICATIONS: MNEI has been proved to be a high-potency sweetener for beverages, but the possibility to use it in semisolid foodstuff was not investigated yet. This study represented a preliminary characterization of two variants of natural sweetener monellin, MNEI and Y65R in semisolid model foodstuff. The data were an important scientific contribution to the knowledge of sweet proteins in agar-based gels and could be useful in order to extend the possible application of these sweet proteins as low calorie sweeteners in semisolid foodstuffs. Some problems concerning their delivered sweetness in agar gels were underlined and their application should be optimized in order to improve sweetness conveyed.

Unraveling the complexity of transcriptomic, metabolomic and quality environmental response of tomato fruit.

BACKGROUND: The environment has a profound influence on the organoleptic quality of tomato (Solanum lycopersicum) fruit, the extent of which depends on a well-regulated and dynamic interplay among genes, metabolites and sensorial attributes. We used a systems biology approach to elucidate the complex interacting mechanisms regulating the plasticity of sensorial traits. To investigate environmentally challenged transcriptomic and metabolomic remodeling and evaluate the organoleptic consequences of such variations we grown three tomato varieties, Heinz 1706, whose genome was sequenced as reference and two "local" ones, San Marzano and Vesuviano in two different locations of Campania region (Italy). RESULTS: Responses to environment were more pronounced in the two "local" genotypes, rather than in the Heinz 1706. The overall genetic composition of each genotype, acting in trans, modulated the specific response to environment. Duplicated genes and transcription factors, establishing different number of network connections by gaining or losing links, play a dominant role in shaping organoleptic profile. The fundamental role of cell wall metabolism in tuning all the quality attributes, including the sensorial perception, was also highlighted. CONCLUSIONS: Although similar fruit-related quality processes are activated in the same environment, different tomato genotypes follow distinct transcriptomic, metabolomic and sensorial trajectories depending on their own genetic makeup.

From raw material to dish: pasta quality step by step.

Pasta is a traditional Italian cereal-based food that is popular worldwide because of its convenience, versatility, sensory and nutritional value. The aim of this review is to present a step-by-step guide to facilitate the understanding of the most important events that can affect pasta characteristics, directing the reader to the appropriate production steps. Owing to its unique flavor, color, composition and rheological properties, durum wheat semolina is the best raw material for pasta production. Although pasta is traditionally made from only two ingredients, sensory quality and chemical/physical characteristics of the final product may vary greatly. Starting from the same ingredients, there are a lot of different events in each step of pasta production that can result in the development of varieties of pasta with different characteristics. In particular, numerous studies have demonstrated the importance of temperature and humidity conditions of the pasta drying operation as well as the significance of the choice of raw material and operating conditions on pasta quality.