Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Food Res Int ; 147: 110584, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399552

RESUMO

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.


Assuntos
Água Carbonatada , Humanos , Propiltiouracila , Sensação , Água
2.
Foods ; 10(5)2021 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-34066774

RESUMO

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.

3.
Nutrients ; 13(3)2021 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-33800789

RESUMO

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.


Assuntos
Preferências Alimentares/psicologia , Alimentos Fortificados/análise , Fenol , Edulcorantes/análise , Limiar Gustativo/efeitos dos fármacos , Adolescente , Adulto , Idoso , Análise por Conglomerados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Personalidade , Propiltiouracila , Adulto Jovem
4.
Foods ; 9(12)2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33255640

RESUMO

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.

5.
Food Res Int ; 138(Pt B): 109813, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33288188

RESUMO

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.


Assuntos
Queijo , Feminino , Humanos , Itália , Percepção , Paladar
6.
Nutrients ; 12(6)2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32549267

RESUMO

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.


Assuntos
Fatores Etários , Transtorno da Evitação ou Restrição da Ingestão de Alimentos , Dieta Mediterrânea , Meio Ambiente , Fatores Sexuais , Adolescente , Adulto , Animais , Estudos Transversais , Comportamento Alimentar , Feminino , Peixes , Frutas , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente/psicologia , Cooperação do Paciente/estatística & dados numéricos , Verduras , Adulto Jovem
7.
J Texture Stud ; 51(2): 242-251, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31598970

RESUMO

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.


Assuntos
Laticínios , Grão Comestível , Alimentos , Sensação , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
8.
Nutrients ; 11(6)2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31200523

RESUMO

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.


Assuntos
Dieta/psicologia , Preferências Alimentares/psicologia , Fenóis/análise , Reconhecimento Psicológico , Paladar , Adolescente , Adulto , Fatores Etários , Bebidas/análise , Café , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Plantas Comestíveis , Propiltiouracila/análise , Chá , Verduras/química , Adulto Jovem
9.
Chem Senses ; 43(9): 697-710, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30204849

RESUMO

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.


Assuntos
Propiltiouracila/farmacologia , Papilas Gustativas/efeitos dos fármacos , Percepção Gustatória/fisiologia , Adolescente , Adulto , Feminino , Preferências Alimentares , Humanos , Masculino , Pessoa de Meia-Idade , Papilas Gustativas/fisiologia , Adulto Jovem
10.
Food Funct ; 9(1): 476-484, 2018 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-29235594

RESUMO

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.


Assuntos
Apetite , Endocanabinoides/metabolismo , Etanolaminas/metabolismo , Saliva/química , Paladar , Adulto , Endocanabinoides/análise , Etanolaminas/análise , Feminino , Análise de Alimentos , Humanos , Masculino , Mastigação , Saliva/metabolismo , Adulto Jovem
11.
J Dairy Sci ; 100(12): 9539-9550, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28987582

RESUMO

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.


Assuntos
Aspartame/análise , Sacarose/análise , Edulcorantes/análise , Paladar , Iogurte/análise , Adulto , Animais , Feminino , Fermentação , Frutas/química , Humanos , Masculino , Reologia
12.
J Texture Stud ; 48(2): 103-113, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28370108

RESUMO

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.


Assuntos
Ágar/química , Géis/química , Proteínas de Plantas/química , Edulcorantes/química , Aspartame , Bebidas , Proteínas Mutantes/química , Sacarina , Sacarose , Percepção Gustatória , Fatores de Tempo
13.
BMC Plant Biol ; 17(1): 66, 2017 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-28347287

RESUMO

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.


Assuntos
Frutas/genética , Frutas/metabolismo , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Qualidade dos Alimentos , Frutas/fisiologia , Dosagem de Genes , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Genótipo , Itália , Metaboloma , Biologia de Sistemas/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcriptoma
14.
J Sci Food Agric ; 95(13): 2579-87, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25783568

RESUMO

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.


Assuntos
Dessecação/métodos , Grão Comestível , Farinha/análise , Manipulação de Alimentos/métodos , Valor Nutritivo , Triticum , Culinária/métodos , Humanos
15.
Food Chem ; 173: 1179-86, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25466141

RESUMO

Sweet proteins represent a class of natural molecules, which are extremely interesting regarding their potential use as safe low-calories sweeteners for individuals who need to control sugar intake, such as obese or diabetic subjects. Punctual mutations of amino acid residues of MNEI, a single chain derivative of the natural sweet protein monellin, allow the modulation of its taste. In this study we present a structural and functional comparison between MNEI and a sweeter mutant Y65R, containing an extra positive charge on the protein surface, in conditions mimicking those of typical beverages. Y65R exhibits superior sweetness in all the experimental conditions tested, has a better solubility at mild acidic pH and preserves a significant thermal stability in a wide range of pH conditions, although slightly lower than MNEI. Our findings confirm the advantages of structure-guided protein engineering to design improved low-calorie sweeteners and excipients for food and pharmaceutical preparations.


Assuntos
Proteínas de Plantas/química , Relação Estrutura-Atividade , Edulcorantes/química , Dicroísmo Circular , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Simulação de Dinâmica Molecular , Proteínas Mutantes/química , Conformação Proteica , Paladar
16.
Food Chem ; 139(1-4): 515-20, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23561139

RESUMO

Radio frequency (RF) heating has been used for numerous applications in the food industry such as baking, thawing or pasteurisation. It reduces cooking time, and it helps to retain acceptable food colour and texture. In this paper, chemical and sensory data obtained from broccoli, potatoes, salmon and cocoa cakes cooked using an innovative RF oven were reported. The oven has an algorithm able to monitor the energy feedback from the cavity and to adjust the energy output accordingly. The different foods were cooked to the same end point and the concentration of phytochemicals, vitamins and acrylamide were assessed. Results demonstrated that RF oven preserved ascorbic acid and increased glucosinolates concentration in broccoli and it decreased the formation of acrylamide in roasted potatoes more than 50%. The total amount of vitamins B was 30% and 50% higher in RF cooked salmon than conventionally cooked salmon prepared at 55 and 75°C, respectively.


Assuntos
Culinária/métodos , Análise de Alimentos , Paladar , Animais , Culinária/instrumentação , Humanos , Produtos da Carne/análise , Ondas de Rádio
17.
Int J Food Microbiol ; 158(3): 186-94, 2012 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-22883207

RESUMO

An antimicrobial polyethylene (PE) film was obtained by coating a nisin-based antimicrobial solution. PE sheets were coated on both sides and were used for the packaging of beefsteaks to be stored in air or modified atmosphere packaging (MAP, 60% O2-40% CO2). Microbial populations, species diversity, headspace volatile organic compounds, colour and sensory properties were monitored after 0, 1, 7 and 12 days of storage at 4 °C. The viable counts showed that there was an effect of MAP and antimicrobial film on the development of all the spoilage associated microbial populations. Carnobacterium spp., Brochothrix thermosphacta, Pseudomonas fragi and Rhanella aquatilis were found in most of the samples. C. maltaromaticum was identified in MRS bulk cells from samples stored in air as well as MAP. Quantitative data of headspace-SPME-GC/MS analysis showed that during storage the production of volatile organic compounds (VOCs) was affected by the use of the treated film and the MAP storage. Compounds such as phenylethylalcohol, nonanal, decanal and ethylbutanoate were produced only from 7 to 12 day of storage and only in the samples stored in air. In agreement with the microbiological and VOCs data, the meat stored in active packaging scored the best rankings in the sensory evaluation. Principal component analysis of microbial, sensory and instrumental data showed that beefsteaks stored with the combination of MAP and active packaging for 12 days at 4 °C differed from the other samples that were more associated to high microbial loads, VOCs concentration and meat off odour perception. In conclusion, the antimicrobial sheets in combination with MAP storage at 4 °C were effective for the storage of beefsteaks by retarding the growth of spoilage bacteria, determining lower concentration of VOCs and keeping acceptable levels of colour and other sensory parameters for more than 10 days.


Assuntos
Bactérias/isolamento & purificação , Embalagem de Alimentos , Conservação de Alimentos/métodos , Carne/microbiologia , Animais , Anti-Infecciosos , Atmosfera , Bactérias/crescimento & desenvolvimento , Dióxido de Carbono/análise , Carnobacterium , Bovinos , Microbiologia de Alimentos , Carne/análise , Odorantes/análise , Polietileno , Temperatura , Compostos Orgânicos Voláteis/análise
18.
Appl Environ Microbiol ; 77(20): 7382-93, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21784913

RESUMO

One hundred three isolates of Carnobacterium spp. from raw meat were analyzed by random amplification of polymorphic DNA (RAPD) and PCR and were identified by 16S rRNA gene sequencing. Forty-five strains of Carnobacterium maltaromaticum were characterized for their growth capabilities at different temperatures, NaCl concentrations, and pH values and for in vitro lipolytic and proteolytic activities. Moreover, their spoilage potential in meat was investigated by analyzing the release of volatile organic compounds (VOCs) in meat stored in air or vacuum packs. Almost all the strains were able to grow at 4, 10, and 20°C, at pH values of 6 to 9, and in the presence of 2.5% NaCl. The release of VOCs by each strain in beef stored at 4°C in air and vacuum packs was evaluated by headspace solid-phase microextraction (HS-SPME)-gas chromatography-mass spectrometry (GC-MS) analysis. All the meat samples inoculated and stored in air showed higher numbers of VOCs than the vacuum-packed meat samples. Acetoin, 1-octen-3-ol, and butanoic acid were the compounds most frequently found under both storage conditions. The contaminated meat samples were evaluated by a sensory panel; the results indicated that for all sensory odors, no effect of strain was significant (P > 0.05). The storage conditions significantly affected (P < 0.05) the perception of dairy, spoiled-meat, and mozzarella cheese odors, which were more intense in meat stored in air than in vacuum packs but were never very intense. In conclusion, different strains of C. maltaromaticum can grow efficiently in meat stored at low temperatures both in air and in vacuum packs, producing volatile molecules with low sensory impacts, with a negligible contribution to meat spoilage overall.


Assuntos
Carnobacterium/classificação , Carnobacterium/isolamento & purificação , Embalagem de Alimentos/métodos , Armazenamento de Alimentos/métodos , Carne/microbiologia , Ar , Carnobacterium/genética , Carnobacterium/metabolismo , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Cromatografia Gasosa-Espectrometria de Massas , Genótipo , Concentração de Íons de Hidrogênio , Tipagem Molecular , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Sequência de DNA , Cloreto de Sódio/metabolismo , Temperatura , Vácuo , Compostos Orgânicos Voláteis/metabolismo
19.
Int J Food Microbiol ; 142(1-2): 120-31, 2010 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-20627208

RESUMO

The functional diversity of a population of sixty-five different strains of P. fragi isolated from fresh and spoiled meat was studied in order to evaluate the population heterogeneity related to meat spoilage potential. The strains were characterized for the proteolytic activity at 4 degrees C on beef sarcoplasmic proteins and only 9 strains were found to be proteolytic. An iron-dependent growth behaviour was shown when each strain was grown in citrate medium containing either myoglobin, haemoglobin or iron chloride as iron sources. Increase of maximum population and mu(max) in presence of different iron sources was registered. The release of volatile organic compounds (VOC) by each strain in beef during aerobic storage at 4 degrees C was evaluated by GC-MS. A considerable variability of occurrence of each molecule in the GC-MS profiles obtained by the different strains was observed ranging from 3% to 79% although the strains showed a high degree of similarity. In particular, ethylhexanoate, ethyloctanoate, ethylnonenoate, ethyldecanoate, 1-octen-3-ol, 3-octanone, 4-methylthiophenol, and 2-pentylfurane were produced by more than 50% of the strains. Representative strains were used to spoil meat in the same conditions used for the VOC analysis and the samples were evaluated by a sensory panel. The results of the sensory analysis indicated that the different strains could significantly affect the odour of meat and strains characterized by production of esters gave fruity odours to the spoiled meat. However, the similarity of strains based on the sensory profiles does not necessarily match the similarity shown in VOC profiles. P. fragi has a significant role in the microbial ecology of meat and the influence of meat-related sources of iron on the growth behaviour of many different strains suggests that meat can be an ecological niche for P. fragi. Regardless of the proteolytic and lipolytic capacities shown in vitro, different molecular types of P. fragi can release odour active volatile molecules and play a similar overall role as spoilage agents of meat.


Assuntos
Contaminação de Alimentos/análise , Carne/microbiologia , Pseudomonas fragi/isolamento & purificação , Animais , Bovinos , Galinhas , Carne/análise , Dados de Sequência Molecular , Filogenia , Pseudomonas fragi/classificação , Pseudomonas fragi/genética , Pseudomonas fragi/metabolismo , Suínos , Compostos Orgânicos Voláteis/metabolismo
20.
Food Microbiol ; 25(2): 335-47, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18206776

RESUMO

In this study, three starter formulations including Lactobacillus curvatus and Staphylococcus xylosus strains selected in vitro on the basis of their lipolytic and proteolytic activities were employed for the manufacture of traditional fermented sausages of southern Italy. Microbial population, proteolysis, lipolysis, changes in free amino acids (FAA) and free fatty acids (FFA) and development of characteristic taste and flavor of the final product were investigated. Proteolysis and lipolysis were observed in sausages inoculated with proteolytic and lipolytic S. xylosus coupled with L. curvatus, while the sausage started with only S. xylosus without lactobacilli was identical to the non-inoculated control, indicating that the proteolysis could be due to both microbial activity and endogenous proteases activated by the decrease in pH. The statistical analysis applied to the instrumental and sensory data showed that there was an effect of the starter used on the characteristics of the sausage obtained. In particular, the control samples showed very close features different from the sausages obtained by adding starter cultures. Finally, analyzing the sensory parameters the sausages ripened without starter addition and those started without the L. curvatus AVL3 showed similar features indicating an influence of the presence of the lactobacilli on the final organoleptic quality of the sausages. An appropriate choice of a combination of strains in a starter formulation is fundamental to obtain products of the expected quality.


Assuntos
Manipulação de Alimentos/métodos , Lactobacillus/metabolismo , Produtos da Carne/microbiologia , Staphylococcus/metabolismo , Paladar , Tecido Adiposo/metabolismo , Aminoácidos/análise , Animais , Contagem de Colônia Microbiana , Ácidos Graxos não Esterificados/análise , Fermentação , Microbiologia de Alimentos , Concentração de Íons de Hidrogênio , Lipólise , Produtos da Carne/normas , Proteínas Musculares/metabolismo , Peptídeo Hidrolases/metabolismo , Análise de Componente Principal , Suínos , Água/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...