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1.
Ultrason Sonochem ; 77: 105685, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34364069

RESUMO

Protein oxidation leads to covalent modification of structure and deterioration of functional properties of quinoa protein. The objective of this study was to investigate the effects of ultrasonic treatment on the functional and physicochemical properties of quinoa protein oxidation aggregates. In this concern, 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) was selected as oxidative modification of quinoa protein. The microstructure of quinoa protein displayed by scanning electron microscope (SEM) indicated that oxidation induced extensive aggregation, leading to carbonylation and degradation of sulfhydryl groups. Aggregation induced by oxidation had a negative effect on the solubility, turbidity, emulsifying stability. However, according to the analysis of physicochemical properties, ultrasonic significantly improved the water solubility of quinoa protein. The quinoa protein treated by ultrasonic for 30 min exhibited the best dispersion stability in water, which corresponded to the highest ζ-potential, smallest particle size and most uniform distribution. Based on the FT-IR, SDS-PAGE and surface hydrophobicity analysis, the increase of α-helix, ß-turn and surface hydrophobicity caused by cavitation effect appeared to be the main mechanism of quinoa protein solubilization. In addition, the hydrophobic region of the protein was re-buried by excessive ultrasonic treatment, and the protein molecules were reaggregated by disulfide bonds. Microstructural observations further confirmed that ultrasonic treatment effectively inhibited protein aggregation and improved the functional properties of quinoa protein.


Assuntos
Chenopodium quinoa/química , Proteínas de Plantas/química , Agregados Proteicos , Ondas Ultrassônicas , Amidinas/química , Qualidade dos Alimentos , Oxirredução
2.
Food Res Int ; 147: 110552, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399529

RESUMO

There is a growing demand for the consumption of nutritious and safe food products. Cold plasma is a novel non-thermal technology that in recent years, has found numerous applications in the food industry. Study on the applications of this technology and its effects on food quality is increasing. Like any other technology, using cold plasma for the processing of foods can be associated with food quality challenges. This paper reviews the effect of cold plasma on the chemical structure of different food constituents as well as its influence on food characteristics. The emphasis is on the recent studies about the plasma mechanisms of action and chemical alterations of different food components. The studies show that the interaction of plasma-reactive species with food components depends on process conditions. Developing the functional characteristics and reducing the anti-nutritional compounds are of promising potentials of cold plasma. Finally, the research gaps, the salient drawbacks, and future prospects of this technology are highlighted.


Assuntos
Gases em Plasma , Alérgenos , Alimentos , Manipulação de Alimentos , Qualidade dos Alimentos
3.
Molecules ; 26(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34443325

RESUMO

Camellia oil (CA), mainly produced in southern China, has always been called Oriental olive oil (OL) due to its similar physicochemical properties to OL. The high nutritional value and high selling price of CA make mixing it with other low-quality oils prevalent, in order to make huge profits. In this paper, the transverse relaxation time (T2) distribution of different brands of CA and OL, and the variation in transverse relaxation parameters when adulterated with corn oil (CO), were assessed via low field nuclear magnetic resonance (LF-NMR) imagery. The nutritional compositions of CA and OL and their quality indices were obtained via high field NMR (HF-NMR) spectroscopy. The results show that the fatty acid evaluation indices values, including for squalene, oleic acid, linolenic acid and iodine, were higher in CA than in OL, indicating the nutritional value of CA. The adulterated CA with a content of CO more than 20% can be correctly identified by principal component analysis or partial least squares discriminant analysis, and the blended oils could be successfully classified by orthogonal partial least squares discriminant analysis, with an accuracy of 100% when the adulteration ratio was above 30%. These results indicate the practicability of LF-NMR in the rapid screening of food authenticity.


Assuntos
Camellia/química , Qualidade dos Alimentos , Óleos Vegetais/química , Espectroscopia de Prótons por Ressonância Magnética , Análise Discriminante , Contaminação de Alimentos , Análise dos Mínimos Quadrados
4.
Molecules ; 26(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34443558

RESUMO

The volatile profiles of 51 samples from 12 monofloral-labelled Portuguese honey types were assessed. Honeys of bell heather, carob tree, chestnut, eucalyptus, incense, lavender, orange, rape, raspberry, rosemary, sunflower and strawberry tree were collected from several regions from mainland Portugal and from the Azores Islands. When available, the corresponding flower volatiles were comparatively evaluated. Honey volatiles were isolated using two different extraction methods, solid-phase microextraction (SPME) and hydrodistillation (HD), with HD proving to be more effective in the number of volatiles extracted. Agglomerative cluster analysis of honey HD volatiles evidenced two main clusters, one of which had nine sub-clusters. Components grouped by biosynthetic pathway defined alkanes and fatty acids as dominant, namely n-nonadecane, n-heneicosane, n-tricosane and n-pentacosane and palmitic, linoleic and oleic acids. Oxygen-containing monoterpenes, such as cis- and trans-linalool oxide (furanoid), hotrienol and the apocarotenoid α-isophorone, were also present in lower amounts. Aromatic amino acid derivatives were also identified, namely benzene acetaldehyde and 3,4,5-trimethylphenol. Fully grown classification tree analysis allowed the identification of the most relevant volatiles for discriminating the different honey types. Twelve volatile compounds were enough to fully discriminate eleven honey types (92%) according to the botanical origin.


Assuntos
Mel/análise , Compostos Orgânicos Voláteis/análise , Análise de Alimentos , Qualidade dos Alimentos
5.
Nutrients ; 13(7)2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34371969

RESUMO

The prevalence of diet-related non-communicable diseases is on the rise in the countries of the Eastern Mediterranean, including Lebanon. This study aimed to provide data on fatty acid profiles and ratios of Lebanese composite dishes, Arabic sweets, and market foods. Methods: Thirty types of traditional dishes, collected from five different Lebanese governorates, thirty-seven types of Arabic sweets and forty-six market food products were considered for analysis. Food samples were chemically analyzed for total, unsaturated and saturated fatty acids. The range of total fatty acids in composite dishes, Arabic sweets, and market food products was between 1.2-11.7 g/100 g, 5.3-25.8 g/100 g, and 0.5-100 g/100 g, respectively. Additionally, the range of saturated fatty acids in composite dishes, Arabic sweets, and market food products was between 0.5-4.9 g/100 g, 2.5-23.6 g/100 g and 0.1-56.4 g/100 g, respectively. Furthermore, about 75% of these foods were poor in unsaturated fatty acids. Regarding saturated fatty acid, the polyunsaturated to monounsaturated (P.M.S) ratio was lower than the recommended ratio of 1:1:1 in 96% of samples. To conclude, there is a need to prioritize fat content in foods and consider processing modifications in the food production system with the aim of achieving a higher P:M:S ratio intake among the population.


Assuntos
Dieta/tendências , Ácidos Graxos/análise , Análise de Alimentos , Qualidade dos Alimentos , Cultura , Dieta Saudável , Gorduras na Dieta/análise , Ácidos Graxos Monoinsaturados/análise , Ácidos Graxos Insaturados/análise , Rotulagem de Alimentos , Humanos , Jordânia , Kuweit , Líbano , Oriente Médio , Arábia Saudita , Urbanização
6.
Nutrients ; 13(7)2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34371970

RESUMO

Restaurant meal consumption has increased substantially, but the ability of restaurants to adhere to guidelines for the Mediterranean diet, healthiness and food allergen management is a challenge. This cross-sectional study aims to assess the Mediterranean diet adherence, healthiness, nutritional quality and food allergen management of meals at restaurants in the Tarragona province (Catalonia, Spain). Primary outcomes included adherence to criteria for the Mediterranean diet (AMed) and gluten management (SMAP), nutritional quality of dishes indicated by a green traffic light rating, meal nutrient content and allergen-free options. Secondary outcomes included restaurant staff knowledge about the Mediterranean diet and food allergens. Forty-four restaurants and 297 dishes were analysed. The restaurants fulfilled an average (mean ± SD) of 5.1 ± 1.6 of 9 compulsory AMed criteria and 12.9 ± 2.8 of 18 SMAP criteria. Dishes were mainly rated green for sugar (n = 178/297; 59.9%) but not for energy (n = 23/297; 7.7%) or total fat (n = 18/297; 6.1%). Waiters and cooks received passing scores for food allergen knowledge (5.8 ± 1.7 and 5.5 ± 1.5 out of 10 points, respectively). Restaurants partially met the AMed and SMAP criteria. Increasing fibre and decreasing saturated fat content are necessary to improve consumers' adherence to healthy diets. For restaurant staff, training courses should be considered to improve their food allergen management.


Assuntos
Dieta Saudável , Dieta Mediterrânea , Refeições , Restaurantes , Estudos Transversais , Dieta Livre de Glúten , Dieta Vegana , Dieta Vegetariana , Hipersensibilidade Alimentar , Rotulagem de Alimentos , Qualidade dos Alimentos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Valor Nutritivo , Restaurantes/organização & administração , Espanha
7.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360903

RESUMO

Despite the fact that many studies have examined the effectiveness of different gaseous postharvest treatments applied at low temperature to maintain table grape quality, the use of ethanol vapor has hardly been investigated. Thus, this work has studied the effectiveness of ethanol vapor-generating sachets in the maintenance of It 681-30 table grape quality, a new cultivar, during storage at low temperature and after the shelf-life period at 20 °C. To this end, various quality assessments have been carried out and the effect of the ethanol treatment on the expression of different genes (phenylpropanoids, transcription factors, PRs, and aquaporins) was determined. The results indicated that the application of ethanol vapor reduced the total decay incidence, weight loss, and the rachis browning index in It 681-30 grapes stored at 0 °C and after the shelf-life period at 20 °C, as compared to non-treated samples. Moreover, the modulation of STS7 and the different PR genes analyzed seems to play a part in the molecular mechanisms activated to cope with fungal attacks during the postharvest of It 681-30 grapes, and particularly during the shelf-life period at 20 °C. Furthermore, the expression of aquaporin transcripts was activated in samples showing higher weight loss. Although further work is needed to elucidate the role of ethanol in table grape quality, the results obtained in this work provide new insight into the transcriptional regulation triggered by ethanol treatment.


Assuntos
Temperatura Baixa , Etanol/farmacologia , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Qualidade dos Alimentos , Armazenamento de Alimentos/métodos , Frutas/efeitos dos fármacos , Gases/farmacologia , Vitis/efeitos dos fármacos , Aquaporinas/genética , Frutas/genética , Expressão Gênica/efeitos dos fármacos , Reação de Maillard/efeitos dos fármacos , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Transcrição Genética/efeitos dos fármacos , Vitis/genética , Volatilização
8.
Nutrients ; 13(8)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34444941

RESUMO

Front-of-pack labels can improve the ability of consumers to identify which foods are healthier, making them a useful public health tool. Nutri-Score is a front-of-pack labelling system adopted by several European countries. This system ranks foods according to their nutritional quality, but does not consider other dimensions such as the degree of food processing. The aim of this study is to compare the nutritional quality (as assessed by Nutri-Score) and the ultra-processing (as assessed by the NOVA classification) of foods in the Open Food Facts database. A simple correspondence analysis was carried out to study the relationship between the two systems. Ultra-processed foods (NOVA 4) were found in all Nutri-Score categories, ranging from 26.08% in nutritional category A, 51.48% in category B, 59.09% in category C, 67.39% in category D to up to 83.69% in nutritional category E. Given the negative effect that the consumption of ultra-processed foods has on different aspects of health, front-of-pack labelling with Nutri-Score should at least be accompanied by complementary labelling indicating the level of processing, such as the NOVA classification.


Assuntos
Rotulagem de Alimentos/métodos , Valor Nutritivo , Comportamento do Consumidor , Bases de Dados Factuais , Europa (Continente) , Fast Foods , Manipulação de Alimentos , Preferências Alimentares , Qualidade dos Alimentos , Humanos , Espanha
9.
Sensors (Basel) ; 21(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208559

RESUMO

This study was performed to test bioimpedance as a tool to detect the effect of different thawing methods on meat quality to aid in the eventual creation of an electric impedance-based food quality monitoring system. The electric impedance was measured for fresh pork, thawed pork, and during quick and slow thawing. A clear difference was observed between fresh and thawed samples for both impedance parameters. Impedance was different between the fresh and the frozen-thawed samples, but there were no impedance differences between frozen-thawed samples and the ones that were frozen-thawed and then stored at +3 °C for an additional 16 h after thawing. The phase angle was also different between fresh and the frozen-thawed samples. At high frequency, there were small, but clear phase angle differences between frozen-thawed samples and the samples that were frozen-thawed and subsequently stored for more than 16 h at +3 °C. Furthermore, the deep learning model LSTM-RNN (long short-term memory recurrent neural network) was found to be a promising way to classify the different methods of thawing.


Assuntos
Espectroscopia Dielétrica , Carne , Estudos de Viabilidade , Qualidade dos Alimentos , Congelamento , Carne/análise
10.
Ultrason Sonochem ; 76: 105657, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34229120

RESUMO

This research evaluated the effects of multi-frequency ultrasound assisted freezing (UAF) on the freezing rate, structural characteristics, and quality properties of cultured large yellow croaker. The freezing effects with triple ultrasound-assisted freezing (TUF) at 20, 28 and 40 kHz under 175 W was more obvious than that of single ultrasound-assisted freezing (SUF) at 20 kHz and dual ultrasound-assisted freezing (DUF) at 20 and 28 kHz. The results showed that UAF significantly increased the freezing rate and better preserved the quality of frozen large yellow croaker samples. Specifically, the quality parameters of the TUF-treated samples were closer to those of the fresh samples, with greater texture characteristics, a larger water holding capacity (lower thawing loss and cooking loss), lower K values and lower thiobarbituric acid reactive substances values. Light microscopy observation images revealed that the ice crystals formed by TUF were fine and evenly distributed, resulting in less damage to the frozen large yellow croaker samples. Therefore, multi-frequency UAF could improve the quality properties of the large yellow croaker samples.


Assuntos
Qualidade dos Alimentos , Congelamento , Perciformes , Ondas Ultrassônicas , Animais
11.
Ultrason Sonochem ; 76: 105660, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34271395

RESUMO

A novel technique for treating grass carp by combining plasma functionalized liquids and ultrasound to inactivate bacteria was developed. The effects of the plasma functionalized liquids (PFL) including plasma functionalized water (PFW) and buffer (PFB) and their respective combination with ultrasound treatment (USPFW and USPFB) on the oxidative and physical qualities of grass carp were also investigated. Individual applications of PFW and PFB significantly reduced the populations of Escherichia coli and Shewanella putrefaciens in the range of 0.31-1.18 log CFU/g, compared with the control with a reduction of 0.18 log CFU/g, while combined treatments of USPFW and USPFB presented additional reductions of 0.05-0.65 log CFU/g, with potential synergy demonstrated for PFW and ultrasound. The treatment resulted in improved biomedical index and nutritional value of fatty acids and lipids, protein structural unfolding, increased lipid oxidation and protein degradation with values within the acceptable limits, and the combined treatment was more effective for retarding the hardness reduction in grass carp, while the colour change was also significantly affected, resulting in increased whiteness. The results indicated that the combined treatments may be a promising approach to improving the quality of seafood products.


Assuntos
Carpas/microbiologia , Qualidade dos Alimentos , Viabilidade Microbiana/efeitos dos fármacos , Gases em Plasma/farmacologia , Ondas Ultrassônicas , Animais
12.
Molecules ; 26(13)2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34279391

RESUMO

Alternative technologies, which have been developed in order to meet the consumers' demand for nourishing and healthy meat and meat products, are followed by the food industry. In the present study, it was determined, using the HPLC method, that green tea contains a high level of epicatechin (EP) under optimal conditions and that pomegranate peel contains a high level of punicalagin (PN). Green tea, pomegranate peel, EP and PN were added to meatballs at different concentrations in eight groups. The antioxidant capacities of extracts were measured. The antimicrobial activity was examined for 72 h using three different food pathogens. The highest level of antimicrobial activity was achieved in the 1% punicalagin group, whereas the minimum inhibition concentration (L. monocytogenes, S. typhimurium) was found to be 1.87 mg/mL. A statistically significant decrease was found in FFA, POV and TBARS levels of meatballs on different days of storage (p < 0.05). When compared to the control group, the bioactive compounds preserved the microbiological and chemical properties of meatballs during storage at +4 °C (14 days). It was concluded that the extracts with high EP and PN concentrations can be used as bio-preservative agents for meat and meat products.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Catequina/química , Aditivos Alimentares/química , Taninos Hidrolisáveis/química , Produtos da Carne/normas , Extratos Vegetais/química , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Camellia sinensis/química , Catequina/farmacologia , Flavonoides/análise , Aditivos Alimentares/farmacologia , Qualidade dos Alimentos , Taninos Hidrolisáveis/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Extratos Vegetais/farmacologia , Romã (Fruta)/química , Carne Vermelha/normas , Salmonella typhimurium/efeitos dos fármacos
13.
Molecules ; 26(12)2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34204744

RESUMO

The cambuci is a native Brazilian fruit from the Atlantic Forest biome. A soft and astringent pulp, a green color, and a sweet aroma are its main characteristics. Classical food quality attributes (fresh fruit mass, fruit height, diameters, total soluble solid, titratable acidity, and ratio) and the metabolic profile from ten accessions from three different locations were analyzed herein by analytical methods (refractometry and neutralization titration) and nuclear magnetic resonance spectroscopy. Concerning sugar content, sucrose was the predominant compound, with glucose and fructose alternating in second, depending on the accession. Citric acid was the most relevant acid, followed by shikimic and quinic acids in quite variable amounts. These three main acids vary in amounts for each accession. Ascorbic acid content emerges as an important quality attribute and makes this fruit nutritionally attractive, due to values comparable to those contained in citric fruits. The main amino acids identified in cambuci were glutamic acid individually or in comprising the tripeptide glutathione (glutamic acid, cysteine, glycine). The quality diversity of the evaluated accessions suggests the potentiality of cambuci use in future breeding programs.


Assuntos
Frutas/química , Frutas/metabolismo , Myrtaceae/metabolismo , Ácidos/metabolismo , Antioxidantes/análise , Ácido Ascórbico/análise , Brasil , Carboidratos/análise , Qualidade dos Alimentos , Frutose/metabolismo , Glucose/metabolismo , Metaboloma , Metabolômica/métodos , Floresta Úmida
14.
Food Chem ; 361: 130160, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062457

RESUMO

The quality of crustaceans' flesh has direct impact on consumers' purchase choices, with water environment and dietary nutrition being effective ways to regulate flesh quality. The aim of present study was to investigate the impacts of water salinity (low, 4 and medium, 23) and dietary lipid source (fish oil and soybean oil) on nutritional values, texture, taste and odor of flesh of mud crab. While water salinity had no significant influence on nutritional values of crab flesh, crabs fed soybean oil displayed significantly lower contents of amino acids and n-3 PUFAs in muscle. However, crabs reared at low salinity showed reduced flesh hardness, chewiness and gumminess likely related to altered myofiber structure, that impacted muscle texture. Furthermore, low salinity and dietary soybean oil weakened umami taste and aroma characteristics of crab flesh associated with decreased contents of free amino acids, flavor nucleotides, inorganic ions and odor active compounds in flesh.


Assuntos
Ração Animal , Aquicultura/métodos , Braquiúros/química , Frutos do Mar/análise , Aminoácidos/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Gorduras na Dieta/farmacologia , Óleos de Peixe/farmacologia , Qualidade dos Alimentos , Valor Nutritivo , Salinidade , Proteínas de Frutos do Mar/análise , Óleo de Soja/farmacologia , Paladar , Compostos Orgânicos Voláteis/análise
15.
Food Chem ; 361: 130154, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34077882

RESUMO

The implementation of Raman and infrared spectroscopy with three data fusion strategies to predict pH and % IMF content of red meat was investigated. Raman and FTIR systems were utilized to assess quality parameters of intact red meat. Quantitative models were built using PLS, with model performances assessed with respect to the determination coefficient (R2), root mean square error and normalized root mean square error (NRMSEP). Results obtained on validation against an independent test set show that the high-level fusion strategy had the best performance in predicting the observed pH; with RP2 and NRMSEP values of 0.73 and 12.9% respectively, whereas low-level fusion strategy showed promise in predicting % IMF (NRMSEP = 8.5%). The fusion of data from more than one technique at low and high level resulted in improvement in the model performances; highlighting the possibility of information enhancement.


Assuntos
Análise de Alimentos/métodos , Carne Vermelha/análise , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodos , Animais , Qualidade dos Alimentos , Concentração de Íons de Hidrogênio , Processamento de Sinais Assistido por Computador
16.
Plant Mol Biol ; 106(4-5): 419-432, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34129189

RESUMO

KEY MESSAGE: Coordinated regulation of amylose and amylopectin synthesis via manipulation of SSII-2, SSII-3 and Wx expression in endosperm can improve rice eating and cooking quality. With increasing rice consumption worldwide, many researchers are working to increase the yield and improve grain quality, especially eating and cooking quality (ECQ). The rice ECQ is mainly controlled by the expression of starch synthesis-related genes (SSRGs) in endosperm. Although the Wx and SSII-3/SSIIa/ALK genes, two major SSRGs, have been manipulated to improve rice ECQ via various breeding approaches, new methods to further improve ECQ are desired. In our previous study, we enhanced rice ECQ by knocking down SSII-2 expression in the japonica Nipponbare cultivar (carrying the Wxb allele) via RNA interference. Herein, the SSII-2 RNAi was introduced into two Nipponbare-derived near-isogenic lines (NILs), Nip(Wxa) and Nip(wx), carrying Wxa and wx alleles respond for high and no amylose levels, respectively. Analysis of physicochemical properties revealed that the improved grain quality of SSII-2 RNAi transgenic lines was achieved by coordinated downregulating the expression of SSII-2, SSII-3 and Wx. To further confirm this conclusion, we generated ssii-2, ssii-3 and ssii-2ssii-3 mutants via CRISPR/Cas9 technique. The amylopectin structure of the resulting ssii-2sii-3 mutants was similar to that in SSII-2 RNAi transgenic lines, and the absence of SSII-2 decreased the amylose content, gelatinisation temperature and rapid visco-analyser profile, indicating essential roles for SSII-2 in the regulation of amylopectin biosynthesis and amylose content in rice endosperm. The effect of SSII-2 was seen only when the activity of SSII-3 was very low or lacking. Our study provides novel approaches and valuable germplasm resources for improving ECQ via plant breeding.


Assuntos
Grão Comestível/genética , Endosperma/genética , Regulação da Expressão Gênica de Plantas , Oryza/genética , Amido/biossíntese , Culinária , Grão Comestível/enzimologia , Grão Comestível/fisiologia , Qualidade dos Alimentos , Oryza/enzimologia , Oryza/fisiologia , Proteínas de Plantas/genética , Interferência de RNA , Amido/genética , Sintase do Amido/genética
17.
Ultrason Sonochem ; 76: 105621, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34144445

RESUMO

Aiming at producing a reduced fat cheese (RFC) as an alternative to full-fat Panela cheese, a highly consumed fresh Mexican dairy product, thermosonication (TS) processes (24 kHz, 400 W nominal power, 2, 4 and 6 min; 50, 55 and 60 °C) were evaluated to treat WPC (80% protein) blended with reduced-fat milk (1 and 2% fat), which were later LTLT pasteurized. TS blends were compared in terms of their technological properties (water holding capacity-WPC, gel firmness- GF, color, pH and titratable acidity) with those of a regular full fat (3%) LTLT pasteurized milk used as a control. Afterwards, a regression analysis was carried out with the obtained data in order to select the most appropriate conditions for cheesemaking purposes (similar GF, higher WHC with respect to the control), minimize both fat content and TS treatment duration to minimize energy expenses. According to these restrictions, the selected conditions were 1.5% fat milk-WPC blend, TS treated at 60 °C for 120 s; 1% fat milk-WPC blend, TS treated at 50 °C for 120 s and 1% fat milk-WPC blend, 50 °C for 144 s, which allowed preparing low fat cheeses (LFCs). These TS treatments were applied in a larger scale to elaborate Panela-type LFCs comparing different technological properties (cheese yield, syneresis, water content, texture profile analysis, color and titratable acidity) with those of a full fat variety, at day 1 and during 14 days of refrigerated storage. Results showed similar texture profiles of LFC cheeses and full fat milk cheeses throughout their storage period with significant changes in composition parameters (higher moisture, protein and salt contents, with low fat percentages), syneresis, selected color parameters (hue, b*), with no observed changes in cheese yield, TA and pH during cheese storage. These promising results are encouraging to develop LFCs with no physicochemical or technological defects using novel processing techniques that may help reducing calorie consumption without compromising sensory acceptability.


Assuntos
Queijo/análise , Gorduras na Dieta/análise , Qualidade dos Alimentos , Sonicação , Temperatura , Proteínas do Soro do Leite/química
18.
Ultrason Sonochem ; 76: 105648, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34182313

RESUMO

Pulsed electric field (PEF) and Ultrasound (US) are commonly used in food processing. We investigated the combined impact of pulsed electric field (PEF) and ultrasound (US) on the wheat plantlet juice. When compared with the individual treatments, the highest values of total phenolics, total flavonoids, chlorophyll, ORAC assay, and DPPH activities were obtained using the combined (US + PEF) methods. The US + PEF significantly decreased the peroxidase and polyphenol oxidase activities from 0.87 to 0.27 Abs min-1 and 0.031-0.016 Abs min-1. Also, the synergistic application significantly lowered the yeast and mold (3.92 to 2.11 log CFU/mL), E. coli/Coliform (1.95 to 0.96 log CFU/mL), and aerobics (4.41 to 2.01 log CFU/mL). Furthermore, Fourier Transform Infrared (FT-IR) and surface-enhanced Raman spectroscopy (SERS) was used to analyzing juice quality. Gold nanoparticles (AuNPs) were used as the SERS substrates, which provided stronger Raman peaks for the samples treated with US + PEF methods. The FT-IR analysis showed significant enhancement of the nutritional molecules. The enhanced quality of wheat plantlet juice combined with lower yeast and mold suggests the suitability of integrated methods for further research and applications.


Assuntos
Eletricidade , Qualidade dos Alimentos , Sucos de Frutas e Vegetais/análise , Sonicação , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Triticum/química
19.
Food Chem ; 362: 130240, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34119950

RESUMO

The alleviating role of starch derivatives on the quality deterioration of frozen steamed bread dough was investigated in terms of derivative structure, the bread characteristics and dough properties including freezable water contents, yeast activity as well as dough viscoelasticity. The addition of starch derivatives including short-clustered maltodextrin (SCMD), DE2 maltodextrin (MD) and pregelatinized starch (PGS) significantly increased the specific volume and decreased the hardness of steamed bread compared with Control bread after 8-week frozen storage. Lower freezable water content was found in PGS dough than SCMD dough, which was consistent with the results of water absorption index of starch derivatives. The analysis of dough gassing rate and yeast survival ratio demonstrated SCMD could provide more cryoprotection for yeast cells. Meanwhile, a higher elastic module and a more continuous gluten-network structure of SCMD dough were found after 8-week frozen storage. These results indicated starch derivatives especially SCMD were promising to be used as the alternative improvers in frozen dough production.


Assuntos
Pão/análise , Pão/normas , Qualidade dos Alimentos , Congelamento , Amido/farmacologia , Tecnologia de Alimentos , Glutens/química , Saccharomyces cerevisiae/efeitos dos fármacos , Amido/química , Vapor , Viscosidade/efeitos dos fármacos , Água/química , Fermento Seco/análise
20.
BMC Plant Biol ; 21(1): 302, 2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34187359

RESUMO

BACKGROUND: Understanding the determinants of free asparagine concentration in wheat grain is necessary to reduce levels of the processing contaminant acrylamide in baked and toasted wheat products. Although crop management strategies can help reduce asparagine concentrations, breeders have limited options to select for genetic variation underlying this trait. Asparagine synthetase enzymes catalyse a critical step in asparagine biosynthesis in plants and, in wheat, are encoded by five homeologous gene triads that exhibit distinct expression profiles. Within this family, TaASN2 genes are highly expressed during grain development but TaASN-B2 is absent in some varieties. RESULTS: Natural genetic diversity in the asparagine synthetase gene family was assessed in different wheat varieties revealing instances of presence/absence variation and other polymorphisms, including some predicted to affect the function of the encoded protein. The presence and absence of TaASN-B2 was determined across a range of UK and global common wheat varieties and related species, showing that the deletion encompassing this gene was already present in some wild emmer wheat genotypes. Expression profiling confirmed that TaASN2 transcripts were only detectable in the grain, while TaASN3.1 genes were highly expressed during the early stages of grain development. TaASN-A2 was the most highly expressed TaASN2 homeologue in most assayed wheat varieties. TaASN-B2 and TaASN-D2 were expressed at similar, lower levels in varieties possessing TaASN-B2. Expression of TaASN-A2 and TaASN-D2 did not increase to compensate for the absence of TaASN-B2, so total TaASN2 expression was lower in varieties lacking TaASN-B2. Consequently, free asparagine concentrations in field-produced grain were, on average, lower in varieties lacking TaASN-B2, although the effect was lost when free asparagine accumulated to very high concentrations as a result of sulphur deficiency. CONCLUSIONS: Selecting wheat genotypes lacking the TaASN-B2 gene may be a simple and rapid way for breeders to reduce free asparagine concentrations in commercial wheat grain.


Assuntos
Asparagina/metabolismo , Aspartato-Amônia Ligase/genética , Deleção de Genes , Triticum/genética , Aspartato-Amônia Ligase/metabolismo , Qualidade dos Alimentos , Genes de Plantas/genética , Estudos de Associação Genética , Variação Genética , Triticum/enzimologia , Triticum/metabolismo
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