Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26.540
Filtrar
1.
Rev Saude Publica ; 55: 13, 2021.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-33886951

RESUMEN

OBJECTIVE: To describe the Nova score for the consumption of ultra-processed foods (UPF) and evaluate its potential in reflecting the dietary share of UPF in Brazil. METHODS: This study was conducted in São Paulo with a convenience sample of 300 adults. Using a tablet, participants answered a 3-minute electronic self-report questionnaire on the consumption of 23 subgroups of UPF commonly consumed in Brazil, regarding the day prior the survey. Each participant score corresponded to the number of subgroups reported. The dietary share of UPF on the day prior to the survey, expressed as a percentage of total energy intake, was calculated based on data collected on a 30-minute complete 24-hour dietary recall administered by trained nutritionists. The association between the score and the dietary share of UPF was evaluated using linear regression models. The Pabak index was used to assess the agreement in participants' classification according to the fifths of Nova score and the fifths of dietary share of UPF. RESULTS: The average dietary share of UPF increased linearly and significantly with the increase of the Nova score for the consumption of ultra-processed foods. We found a substantial agreement in participants' classification according to the fifths of the distribution of scores and the fifths of the dietary share of UPF (Pabak index = 0.67). Age was inversely associated with a relatively high frequency of UPF consumption (upper fifth of the distribution) for both score and dietary share of UPF. CONCLUSION: The Nova score for the consumption of ultra-processed foods, obtained in a quick and practical manner, shows a good potential in reflecting the dietary share of UPF in Brazil.


Asunto(s)
Comida Rápida , Manipulación de Alimentos , Adulto , Brasil , Dieta , Ingestión de Energía , Humanos
2.
Artículo en Inglés | MEDLINE | ID: mdl-33806611

RESUMEN

Starter cultures can be defined as preparations with a large number of cells that include a single type or a mixture of two or more microorganisms that are added to foods in order to take advantage of the compounds or products derived from their metabolism or enzymatic activity. In foods from animal origin, starter cultures are widely used in the dairy industry for cheese, yogurt and other fermented dairy products, in the meat industry, mainly for sausage manufacture, and in the fishery industry for fermented fish products. Usually, microorganisms selected as starter culture are isolated from the native microbiota of traditional products since they are well adapted to the environmental conditions of food processing and are responsible to confer specific appearance, texture, aroma and flavour characteristics. The main function of starter cultures used in food from animal origin, mainly represented by lactic acid bacteria, consists in the rapid production of lactic acid, which causes a reduction in pH, inhibiting the growth of pathogenic and spoilage microorganisms, increasing the shelf-life of fermented foods. Also, production of other metabolites (e.g., lactic acid, acetic acid, propionic acid, benzoic acid, hydrogen peroxide or bacteriocins) improves the safety of foods. Since starter cultures have become the predominant microbiota, it allows food processors to control the fermentation processes, excluding the undesirable flora and decreasing hygienic and manufacturing risks due to deficiencies of microbial origin. Also, stater cultures play an important role in the chemical safety of fermented foods by reduction of biogenic amine and polycyclic aromatic hydrocarbons contents. The present review discusses how starter cultures contribute to improve the microbiological and chemical safety in products of animal origin, namely meat, dairy and fishery products.


Asunto(s)
Queso , Productos de la Carne , Animales , Fermentación , Manipulación de Alimentos , Microbiología de Alimentos
3.
Revista Digital de Postgrado ; 10(1): 280, abr. 2021. tab
Artículo en Español | LILACS, LIVECS | ID: biblio-1147585

RESUMEN

Se evaluó la composición proximal, el contenido de polifenoles totales y la capacidad antioxidante de un chocolate oscuro formulado a partir de granos de cacao orgánico, seco, y no sometido al proceso fermentativo. Este producto fue elaborado con insumos y procesos desarrollados en la Granja Experimental El Cairo, ubicada en la Universidad Nacional de Colombia (GEL-UN), departamento de Arauca, Colombia. El contenido de grasa se encontró entre los rangos conocidos (>50%), siendo una característica ligada al origen genético, y a las condiciones climáticas. El alto contenido de proteínas (16,21%), evidencia que se trata de granos de cacao secos no fermentados. Tal contenido juega un papel importante en la formación de los precursores del sabor y aroma, en chocolates finos y exquisitos. El pH determinado es un indicativo de un chocolate amargo, con bajo índice de fermentación y de baja acidez acética o láctica. El contenido de polifenoles totales se relaciona de manera directa con la alta actividad antioxidante de este chocolate. Se concluye que el tipo de material genético usado como insumo, así como los procesos implementados para la obtención del chocolate, en GEL-UN, contribuyeron para la obtención de un producto tipo comercial, con propiedades funcionales, entre ellas las relacionadas con la capacidad antioxidante(AU)


Thee proximal chemical composition, the content of total polyphenols, and the antioxidant capacity of a dark chocolate formulated from organic, dry cocoa beans and not subjected to the fermentation process were evaluated. This product was made with inputs and processes developed at the El Cairo Experimental Farm, located at the Universidad Nacional de Colombia (CEF-UN), Arauca, Colombia. The fat content was found between the known ranges (> 50%), being a characteristic linked to the genetic origin, and to the climatic conditions. The high protein content (16.21%) evidenced that it´s unfermented dry cocoa beans. Such content plays an important role in the formation of precursors of flavor and aroma, in fine and exquisite chocolates. The determined pH is indicative of a dark chocolate, with a low fermentation index and low acetic or lactic acidity. The content of total polyphenols is directly related to the high antioxidant activity of this chocolate. It is concluded that the type of genetic material used as input, as well as the processes implemented to obtain chocolate, in CEF-UN, contributed to obtaining a commercial type product, with functional properties, including those related to antioxidant capacity(AU)


Asunto(s)
Polifenoles , Chocolate/análisis , Antioxidantes , Cacao , Alimentos Orgánicos , Manipulación de Alimentos
4.
Artículo en Inglés | MEDLINE | ID: mdl-33809470

RESUMEN

Muslim tourism is one of the most rapidly developing sectors in the international tourism industry. Nevertheless, halal food performance and its relationship with international Muslim traveler decision-making and behaviors have not been sufficiently examined. The present research explored the influence of halal food performance, which encompasses availability, health/nutrition, accreditation, and cleanness/safety/hygiene factors, on the Muslim traveler retention process at a non-Islamic destination. A survey methodology with a quantitative data analytic approach was employed to achieve research goals. Our findings indicated that halal food performance increased destination trust and destination attachment, which in turn influenced Muslim traveler retention. Additionally, the efficacy of the higher-order framework of halal food performance was defined. Both destination trust and attachment mediated the effect of halal food performance on retention. A halal-friendly destination image included a moderating influence on the retention process. The effectiveness of the proposed theoretical framework for explicating Muslim traveler behaviors was uncovered. This research better introduces the importance of halal food performance and its attributes for the elicitation of Muslim traveler approach responses and behaviors at a non-Islamic destination to researchers and practitioners.


Asunto(s)
Calidad de los Alimentos , Turismo , Manipulación de Alimentos , Islamismo , Carne/análisis
5.
Int J Food Microbiol ; 344: 109108, 2021 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-33667851

RESUMEN

The study determined the growth kinetic parameters of a cocktail of Listeria monocytogenes 1/2c and 4b strains in coconut water (pH 4.76, 5.0°Brix, 0.09% malic acid, aw 0.998) subjected to low (~2.0 log CFU/mL) and high (~4.0 log CFU/mL) contamination levels, and exposed to different storage temperatures (4 °C, 17 °C, 30 °C, and 35 °C). The pathogen proliferated in all tested conditions except in that with low contamination stored at 4 °C. Despite not growing at 4 °C, the pathogen was detectable throughout the storage period, which lasted for almost 400 h. In conditions where the pathogens proliferated, growth lag (tlag) ranged from 0.0 to 68.3 h. The growth rates (KG) ranged from 0.05 to 0.48 log CFU/h, while the final populations ranged from 6.3 to 8.7 log CFU/mL. Both storage temperature and contamination level significantly (P < 0.05) affected the growth parameters. Sanitary risk times (SRT) were determined with the microbiological shelf life (SL) of coconut water. In some of the conditions tested, SRT took place before SL (SRT < SL), emphasizing the importance of having good hygienic and manufacturing practices in place for such a vulnerable commodity.


Asunto(s)
Cocos/microbiología , Conservación de Alimentos , Almacenamiento de Alimentos , Listeria monocytogenes/crecimiento & desarrollo , Frío , Recuento de Colonia Microbiana , Manipulación de Alimentos , Microbiología de Alimentos , Calor
6.
Molecules ; 26(5)2021 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-33670944

RESUMEN

To counteract the negative effect of salt overconsumption on health, strategies have been developed to reduce the salt content in food products. Among them, two promising strategies based on odour-induced saltiness enhancement and the heterogeneous distribution of flavour compounds were combined and assessed in four-layer cream-based snacks. To investigate the relationship between saltiness enhancement, temporal release and perception of flavour compounds in hot snacks with heterogeneous distribution of salt and aroma compounds, complementary techniques were used: nose space PTR-Tof-MS (Proton Transfer Reaction-Time of Flight-Mass Spectrometry) to assess the release of aroma compounds in vivo, and ATI (Alternate Time-Intensity) and TDS Temporal Dominance of Sensations) to evaluate perception as a function of time. The obtained results confirmed that the strategy of concentrating salt in the outer layer of a multilayer product was the optimal solution with respect to taste intensity. Heterogeneous salt distribution decreased aroma compound release and consequently aroma intensity but in different ways according to both salt and added aroma distribution in the food matrix. The salty taste enhancement could be due to the initial strong dominance of the salty sensation at the very beginning of the eating process. The involved mechanisms rely on a combination of physico-chemical and perceptual effects which are not clear yet.


Asunto(s)
Aromatizantes/química , Manipulación de Alimentos/métodos , Odorantes/análisis , Cloruro de Sodio Dietético/análisis , Análisis de los Alimentos , Humanos , Espectrometría de Masas , Sales (Química)/química , Gusto , Percepción del Gusto
7.
Int J Food Microbiol ; 343: 109107, 2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33662694

RESUMEN

Starter cultures during fermentation of Coffea arabica var. Mundo Novo processed in open stainless-steel vessels by natural and pulped natural methods were studied. The yeasts Meyerozyma caribbica (CCMA 0198), Saccharomyces cerevisiae (CCMA 0543), Candida parapsilosis (CCMA 0544), and Torulaspora delbrueckii (CCMA 0684) were inoculated separately in two different coffee processes: natural and pulped natural. The qPCR (real-time quantitative polymerase chain reaction) was used as a culture-independent method to monitor the inoculum's permanence. Changes in microbial metabolites (organic acids and volatile) production were evaluated by high-performance liquid chromatography (HPLC) and gas chromatograph-mass spectrometry (GC-MS), respectively. The sensory analysis was assessed in roasted beans. The fermentation lasted 27 h, and the coffee temperature ranged from 16.5 to 24.0 °C. The starter culture population was dominant throughout fermentation. S. cerevisiae (CCMA 0543) and T. delbrueckii (CCMA 0684) presented a higher population in natural processing. However, in pulped natural processing, M. caribbica (CCMA 0198) and C. parapsilosis (CCMA 0544) were the dominant populations. Citric, malic, and succinic acids were naturally present in coffee. Lactic, isobutyric, and isovaleric acids were detected at the end of the fermentation in different treatments. Lactic acid was detected in samples at the end of fermentation in Control and CCMA 0198 treatment. NAT coffee inoculated with CCMA 0684 presented isobutyric acid and isovaleric acid concentrations. Volatile compounds, such as 2,6-diethylpyrazine was detected in treatments inoculated with yeasts, but not in Controls. 2-acetoxymethylfuran was only detected in samples inoculated with CCMA 0198 from both NAT and PN methods. Samples fermented with S. cerevisiae (CCMA 0543) presented the highest sensorial scores in both processing (84.75 and 84.92). The inoculated coffee beans showed higher scores of sweetness, long aftertaste, and greater complexity. The starter cultures influenced the sensorial profiles through the synthesis of specific volatile constituents. However, considering all parameters analyzed, S. cerevisiae (CCMA 0543) would be the most suitable yeast for the var. Mundo Novo processed by both fermentation methods.


Asunto(s)
Reactores Biológicos/microbiología , Coffea/microbiología , Manipulación de Alimentos/métodos , Levaduras/metabolismo , Ácidos/análisis , Coffea/química , Fermentación , Sensación , Especificidad de la Especie , Gusto , Compuestos Orgánicos Volátiles/análisis , Levaduras/clasificación , Levaduras/aislamiento & purificación
8.
Food Chem ; 352: 129350, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33657481

RESUMEN

Fermented cassava products are important starchy food staples in South America. The quality of the products is affected by the baking expansion ability of the dough, which is in turn influenced by the starch fermentation process and drying method employed. We investigated the structural properties of cassava starch after different fermentation and drying treatments, and the effect of starch structure on scalding of dough and baking expansion ability. Fermentation combined with either exposure to sunlight or UV light treatment resulted in high cassava starch baking expansion. Moreover, we observed decreased crystallinity and increased disordered crystalline regions with lower molecular weight in the two types of starch-fermented combined with sunlight or UV light treatment-and both appeared to have a continuous network structure and polarized cross in scalded dough, which are conducive to holding gas and losing water, thus promoting high baking expansibility.


Asunto(s)
Manipulación de Alimentos , Manihot/química , Almidón/química , Desecación , Fermentación , Manihot/efectos de la radiación , Peso Molecular , Luz Solar , Rayos Ultravioleta
9.
Food Chem ; 351: 129303, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33647689

RESUMEN

Herein, we investigated the impact of moist (steaming and boiling) and dry (baking and microwaving)-heat treatment processes on the structure and physicochemical properties of wheat starch (WS) supplemented with lauric acid (LA). Elemental composition analysis revealed the interplay between WS and LA. Scanning electron microscopy (SEM) and iodine staining revealed that lamellar crystalline structure of WS-LA complexes was improved after moist-heat treatment (relative to samples without any heat treatments); the finding which is at variance to dry-heat treatment process. Additionally, high resistance to thermal decomposition and a lower 1022/995 cm-1 absorbance ratio were observed in moist-heat treated WS-LA compared with dry-heat samples. Moreover, the V-type diffraction peak intensity and resistance to in vitro enzymatic hydrolysis of samples treated with moist-heat were increased to a greater extent than the dry-heat treated counterparts. In sum, this study would facilitate the application of functional starch-lipid complexes in food necessitated heat treatments.


Asunto(s)
Calor , Ácidos Láuricos/química , Almidón/química , Triticum/química , Digestión , Manipulación de Alimentos , Hidrólisis , Microscopía Electrónica de Rastreo , Almidón/metabolismo
10.
Artículo en Inglés | MEDLINE | ID: mdl-33669645

RESUMEN

Biofilms, present as microorganisms and surviving on surfaces, can increase food cross-contamination, leading to changes in the food industry's cleaning and disinfection dynamics. Biofilm is an association of microorganisms that is irreversibly linked with a surface, contained in an extracellular polymeric substance matrix, which poses a formidable challenge for food industries. To avoid biofilms from forming, and to eliminate them from reversible attachment and irreversible stages, where attached microorganisms improve surface adhesion, a strong disinfectant is required to eliminate bacterial attachments. This review paper tackles biofilm problems from all perspectives, including biofilm-forming pathogens in the food industry, disinfectant resistance of biofilm, and identification methods. As biofilms are largely responsible for food spoilage and outbreaks, they are also considered responsible for damage to food processing equipment. Hence the need to gain good knowledge about all of the factors favouring their development or growth, such as the attachment surface, food matrix components, environmental conditions, the bacterial cells involved, and electrostatic charging of surfaces. Overall, this review study shows the real threat of biofilms in the food industry due to the resistance of disinfectants and the mechanisms developed for their survival, including the intercellular signalling system, the cyclic nucleotide second messenger, and biofilm-associated proteins.


Asunto(s)
Desinfectantes , Microbiología de Alimentos , Biopelículas , Matriz Extracelular de Sustancias Poliméricas , Manipulación de Alimentos , Industria de Alimentos , Industria de Procesamiento de Alimentos
11.
Int J Mol Sci ; 22(5)2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33668158

RESUMEN

Cold plasmas generated by various electrical discharges can affect cell physiology or induce cell damage that may often result in the loss of viability. Many cold plasma-based technologies have emerged in recent years that are aimed at manipulating the cells within various environments or tissues. These include inactivation of microorganisms for the purpose of sterilization, food processing, induction of seeds germination, but also the treatment of cells in the therapy. Mechanisms that underlie the plasma-cell interactions are, however, still poorly understood. Dissection of cellular pathways or structures affected by plasma using simple eukaryotic models is therefore desirable. Yeast Saccharomyces cerevisiae is a traditional model organism with unprecedented impact on our knowledge of processes in eukaryotic cells. As such, it had been also employed in studies of plasma-cell interactions. This review focuses on the effects of cold plasma on yeast cells.


Asunto(s)
Gases em Plasma/farmacología , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/efectos de los fármacos , Manipulación de Alimentos , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismo , Esterilización
13.
Food Chem ; 349: 129159, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33545604

RESUMEN

The effect of dry heat (DH, 130 °C, 1, 3 and 9 h), cold plasma (CP, 40 V, 1, 5 and 10 min) and their combination (D-P) treatment on the structure, physicochemical and digestive properties of red adzuki bean starch were studied. The results showed that DH or CP had slight change in morphology while diffraction pattern of starch was remained. With the extension of treated time of DH and CP, the amylose content, crystallinity, molecular weight, short-range order, the long chain of amylopectin, enthalpy value, swelling power, digestibility were reduced, while gelatinization temperatures, the short chain of amylopectin and solubility were increased. The D-P had deeper modification than the single treatment. The combination of dry heat and cold plasma is a simple and green method to improve the starch structure and enhance starch properties and this modified starch could be implemented to tailor starch to the desired food applications.


Asunto(s)
Frío , Digestión , Calor , Gases em Plasma/química , Almidón/química , Almidón/metabolismo , Vigna/química , Manipulación de Alimentos , Gelatina/química , Peso Molecular , Solubilidad , Termodinámica
14.
Food Chem ; 349: 129162, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33550017

RESUMEN

Coffee is among the most consumed beverages worldwide. The present study reports on the aroma composition associated with coffee seeds brewing. Aroma of authentic coffee specimens of Coffea arabica and C. robusta alongside with typical products consumed in the Middle East were analyzed using HS-SPME coupled with GC-MS. In addition, multivariate data analysis (MVA) was employed. Results revealed for 102 volatiles with a distinct aroma profile between the different brewing methods. Infusion demonstrated higher esters level, while decoction and maceration were more abundant in sesquiterpenes and terpene alcohols, respectively. Besides, heat-induced products, i.e., 4-vinyl guaiacol was identified as potential roasting index in instant coffee and roasted C. robusta brews. Blending with cardamom further masked the smoky odor of such compounds by its fragrant terpinyl acetate. This study provides the first report on the chemical sensory attributes of Middle Eastern coffee blends and further reveal for the impact of brewing, roasting on its aroma composition.


Asunto(s)
Coffea/química , Café/química , Manipulación de Alimentos/métodos , Informática , Odorantes/análisis , Semillas/química , Coffea/crecimiento & desarrollo , Análisis de los Alimentos , Cromatografía de Gases y Espectrometría de Masas , Calor , Medio Oriente
15.
Artículo en Inglés | MEDLINE | ID: mdl-33535597

RESUMEN

The ability to combat food-borne illnesses in food facilities and institutional catering units require sufficient knowledge on food safety and sanitation standards by food producers and consumers. The aim of the study was to investigate the food safety and sanitation knowledge of food handlers in Kenyan high schools. A cross-sectional study was carried out among 204 food handlers in 50 schools. Questions about knowledge and practice toward food safety and sanitation were asked. Respondents were the most knowledgeable on food contamination (93%), while participants were the least knowledgeable on the importance of protective attire when distributing foods to learners (50%). One-way ANOVA revealed a significant difference between gender and food handlers' behavior and practice (F = 19.886, ρ = 0.00 < 0.05) as well as between job tenure and practice of food safety and sanitation (F = 17.874, ρ = 0.00 < 0.05). Multiple regression analysis established that knowledge contributed to 44.1% of the behavior and practice of the food handlers. It is concluded that food handlers have a fair knowledge despite lack of training, motivation, and facilities to maintain quality standards. It is recommended that the Kenyan Government develop and implement guidelines through school feeding policy that would ensure that food safety and sanitation practices are implemented and utilized by Kenyan high schools.


Asunto(s)
Manipulación de Alimentos , Saneamiento , Adolescente , Estudios Transversales , Inocuidad de los Alimentos , Conocimientos, Actitudes y Práctica en Salud , Humanos , Kenia , Instituciones Académicas , Encuestas y Cuestionarios
16.
Int J Food Microbiol ; 341: 109072, 2021 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-33524880

RESUMEN

Proper elimination of bacterial endospores in foods and food processing environment is challenging because of their extreme resistance to various stresses. Often, sporicidal treatments prove insufficient to eradicate the contaminating endospore population as a whole, and might therefore serve as a selection pressure for enhanced endospore resistance. In the sporeforming Bacillus cereus group, Bacillus weihenstephanensis is an important food spoilage organism and potential cereulide producing pathogen, due to its psychrotolerant growth ability at 7 °C. Although the endospores of B. weihenstephanensis are generally less heat resistant compared to their mesophilic or thermotolerant relatives, our data now show that non-emetic B. weihenstephanensis strain LMG 18989T can readily and reproducibly evolve to acquire much enhanced endospore heat resistance. In fact, one of the B. weihenstephanensis mutants from directed evolution by wet heat in this study yielded endospores displaying a > 4-fold increase in D-value at 91 °C compared to the parental strain. Moreover, these mutant endospores retained their superior heat resistance even when sporulation was performed at 10 °C. Interestingly, increased endospore heat resistance did not negatively affect the vegetative growth capacities of the evolved mutants at lower (7 °C) and upper (37 °C) growth temperature boundaries, indicating that the correlation between cardinal growth temperatures and endospore heat resistance which is observed among bacterial sporeformers is not necessarily causal.


Asunto(s)
Bacillus/crecimiento & desarrollo , Bacillus/metabolismo , Esporas Bacterianas/crecimiento & desarrollo , Evolución Biológica , Depsipéptidos/biosíntesis , Manipulación de Alimentos , Calor
17.
Food Chem ; 348: 129092, 2021 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-33529940

RESUMEN

The popping process has been widely used as a technique for obtaining snacks. This study evaluated the effect of the popping process on the structural and thermal properties of sorghum. Seven varieties of sorghum were used. Raw sorghum grains were adjusted to 11% moisture and popped at 210 °C for 90 s with hot air. Microstructure, thermal and viscosity properties, and X-Ray and infrared spectrum were measured in raw and popped sorghum. The popping process produced an ordered honeycomb-like structure in the sorghum. The viscosity profile showed an increase in the thermal stability of popped sorghum. DSC measurements showed a starch gelatinization and a second transition about to 145 °C. XRD diffractograms display a reduction in the amplitude of the crystalline orthorhombic structure peaks. Finally, infrared indicated a change in the short-range structure and protein denaturation due to the popping process.


Asunto(s)
Manipulación de Alimentos , Sorghum/química , Temperatura , Almidón/análisis , Viscosidad
18.
Food Chem ; 350: 129271, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33618095

RESUMEN

In this study, the structural, interfacial, and emulsifying properties of high-intensity ultrasound (HUS)-treated pea protein isolate (PPIUS) were investigated. HUS at 50% amplitude and 57-60 W·cm-2 for 5 min markedly improved protein solubility (by 132%), surface hydrophobicity (by 173%), and reduced particle size (by 52%). These physicochemical changes in PPIUS led to more rapid protein adsorption at the oil-water interface, improved emulsifying activity (by 18-27%) and capacity (by 11%), and enhanced emulsion physical stability. The multilayer nature, albeit less elastic, of the interfacial membrane formed by PPIUS when compared to control protein (PPIC), based on dilatational testing, contributed to the above results. Moreover, PPIUS-stabilized emulsions exhibited a tendency of being less susceptible to lipid oxidation during storage. Thus, structure-modifying HUS may be a valuable processing technology for the manufacture of pea protein-based emulsion foods.


Asunto(s)
Emulsionantes/química , Manipulación de Alimentos/métodos , Proteínas de Guisantes/química , Ondas Ultrasónicas , Adsorción , Interacciones Hidrofóbicas e Hidrofílicas , Oxidación-Reducción , Tamaño de la Partícula , Solubilidad
19.
Food Chem ; 351: 129215, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33639428

RESUMEN

This study describes a turn-on upconversion fluorescence sensor for the detection of acrylamide (AA) based on glutathione (GSH) modulated turn-on fluorescence strategy. Polyethyleneimine-modified upconversion nanoparticles were first prepared by the hydrothermal method and then Rhodamine B derivative (RBD) was loaded on their surface through non-covalent bonding. The GSH coupled with RBD and strongly quenched the upconversion fluorescence via fluorescence resonance energy transfer. Upon addition of tris (2-carboxyethyl) phosphine, the thiol-ene Michael addition reaction between GSH and AA was efficiently catalyzed, resulted in the quenched fluorescence triggered on. Under the optimum conditions, a linear detection range from 0.1 to 104 µM was implemented for AA with a limit of detection of 0.68 nM and great sensitivity was observed. Importantly, the proposed sensor was evaluated for spiked potato chips samples with a satisfactory result in contrast to high-performance liquid chromatography, confirmed its applicability for the rapid detection of AA.


Asunto(s)
Acrilamida/análisis , Acrilamida/química , Transferencia Resonante de Energía de Fluorescencia/instrumentación , Análisis de los Alimentos/métodos , Solanum tuberosum/química , Compuestos de Sulfhidrilo/química , Manipulación de Alimentos , Límite de Detección , Nanopartículas/química
20.
J Dairy Sci ; 104(4): 3916-3926, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33612211

RESUMEN

The solubility of high-protein milk protein concentrate (MPC) may decrease significantly during storage, particularly at relatively high temperatures and humidity. The objective of this study was to seek correlations between the solubility loss of MPC during storage and various surface characteristics determined on the basis of simultaneous nanoscale topographical imaging and nanomechanical mapping of MPC particle surfaces using atomic force microscopy. A control MPC and a calcium-depleted MPC were stored at 45°C and 66% relative humidity for up to 60 d. The solubility of the control MPC was 56% at the beginning of the storage and gradually decreased to 10% at the end of the 60-d storage. The calcium-depleted MPC exhibited more rapid decreases from almost 100% at the beginning of the storage to 18% after storage for 45 d, after which we observed no significant difference in solubility between the control and calcium-depleted MPC. Averaged or root mean squared roughness values calculated using topographical images were found to have no correlation with the solubility. Deformation, Derjaguin-Muller-Toropov modulus, and adhesion images revealed the presence of individual casein micelles and larger clusters of aggregated casein micelles at MPC particle surfaces, whereas we observed no correlation between the solubility and averaged values of these nanomechanical properties. Furthermore, Derjaguin-Muller-Toropov modulus and adhesion images showed that the peripheral edges of individual casein micelles and their clusters had significantly higher values of the corresponding nanomechanical properties than other regions in the images, indicating the occurrence of the fusion of casein micelles. The surface area coverage or the percent area of the fused regions in an image revealed significant negative linear correlations with the solubility for both the control and calcium-depleted MPC. The present results support the hypothesis that the fusion of casein micelles at MPC powder particle surfaces is a causative factor for the solubility loss of MPC during storage and in turn suggest that the solubility loss may be alleviated by inhibiting the formation of a crust or skin on powder particle surfaces.


Asunto(s)
Manipulación de Alimentos , Proteínas de la Leche , Animales , Caseínas , Micelas , Leche/química , Proteínas de la Leche/análisis , Polvos , Solubilidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...