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Packaging for food products is particularly important to preserve product quality and shelf life. The most used materials for food packaging are plastic, glass, metal, and paper. Plastic films produced based on petroleum are widely used for packaging because they have good mechanical properties and help preserve the characteristics of food. However, environmental concerns are leading the trend towards biopolymers. Films and coatings based on biopolymers have been extensively studied in recent years, as they cause less impact on the environment, can be obtained from renewable sources or by-products, are relatively abundant, have a good coating and film-forming capacity, are biodegradable and have nutritional properties that can be beneficial to human health. Whey protein-based films have demonstrated good mechanical resistance and a good barrier to gases when at low relative humidity levels, in addition to demonstrating an excellent barrier to aromatic compounds and especially oils. The use of whey proteins for films or coatings has been extensively studied, as these proteins are edible, have high nutritional value, and are biodegradable. Thus, the main objective of this document was to review new methodologies to improve the physicochemical properties of whey protein films and coatings. Importance will also be given to the combinations of whey proteins with other polymers and the development of new techniques that allow the manipulation of structures at a molecular level. The controlled release and mass transfer of new biomaterials and the improvement of the design of films and packaging materials with the desired functional properties can increase the quality of the films and, consequently, broaden their applications.
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Bovine whey cheese (WC) is a product from southern European countries that presents some challenges: its production process involves high energy inputs; the yield is low; and WC has a short shelf life. The application of ultrafiltration (UF) to bovine whey before manufacture of WC and the employment of protective cultures can reduce these disadvantages. The objective of this research was the production of whey cheeses using ultrafiltrated bovine cheese whey with added probiotics or probiotics plus protective cultures. Three types of WC were produced: control CW without any addition (C); CW with the addition of the probiotic Lactobacillus acidophilus (LA5); and CW with the addition of Lactobacillus acidophilus plus a protective culture containing Lacticaseibacillus paracasei and Lacticaseibacillus rhamnosus (LA5FQ4). The WCs were stored under refrigerated conditions for 28 days. The products with added cultures presented lower pH values and higher titratable acidities when compared to the control. Sample LA5 presented the lowest pH and the highest titratable acidity, while LA5FQ4 presented intermediate values. Slight differences were observed between products regarding color parameters, chiefly resulting from storage time. The samples with added cultures were firmer when compared to the control, with LA5 cheeses showing the highest values at the end of the storage. Lactic acid bacteria (LAB) counts were on the order of log 8-9 CFU/g for the products with added cultures. Lower levels of yeasts and molds were detected on the sample with the protective culture (LA5FQ4), so that by the end of storage they presented counts one log cycle lower than C and LA5. Hence, the beneficial impact of the protective culture on the shelf life of the product is evident. Regarding sensory evaluation, LA5FQ4 cheeses obtained the highest scores for all parameters evaluated. It can be concluded that the use of UF associated with the addition of protective cultures can be very useful to reduce the energy consumption of the manufacturing process, to prolong the shelf life of WC and to improve its sensory properties.
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A growing interest in the recovery and enhancement of crops, particularly local varieties such as 'Caaveiro' wheat, has been observed. This study aims to investigate the impact of cultivation systems (organic versus conventional) on the nutritional quality of 'Caaveiro' flour and breads protected by the PGI "Pan Galego," employing two fermentation methods (sourdough versus sourdough and biological yeast). Organic flour exhibited significantly higher levels of moisture, fat, sucrose, phosphorus (P), sodium (Na), and copper (Cu) while also exhibiting a lower total starch and zinc (Zn) content. Organic bread, produced using both fermentation methods, demonstrated significantly higher protein, carbohydrate, total, resistant, and rapidly digestible starch, ash, Na, P, iron (Fe), and Cu content. Additionally, they contained less moisture compared to conventional bread. Despite variations in nutritional characteristics based on the cultivation system, the organic approach proved effective at producing high-quality products with a positive environmental impact, which is highly appreciated by consumers.
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Sheep's second cheese whey (SCW), the by-product resulting from whey cheese production, was used as a component of cheese coatings containing oregano (Origanum compactum) and clary sage (Salvia sclarea) essential oils (EOs). SCW powder was obtained by the ultrafiltration/diafiltration of SCW followed by reverse osmosis and freeze drying. The coatings were produced with a mixture of SCW and whey protein isolate (WPI) using glycerol as plasticizer. Model cheeses were produced with cow´s milk and those containing SCW:WPI coatings; those with and without EOs were compared to controls without coating and with a commercial coating containing natamycin. At the end of ripening (28 days), the cheeses containing EOs presented higher water activity (ca. 0.930) and moisture content, as well as lower titratable acidity. Concerning color parameters, significant differences were also observed between products and as a result of ripening time. However, the use of SCW:WPI coatings did not significantly influence the color parameters at the end of ripening. Regarding texture parameters, the cheeses containing SCW:WPI coatings presented significantly lower values for hardness, chewiness, and gumminess. Significant differences were also observed for all microbial groups evaluated either between products and as a result of ripening time. In all cases, lactobacilli and lactococci counts surpassed log 7-8 CFU/g, while the counts of yeasts and molds increased steadily from ca. log 3 to log 6 CFU/g. The lowest counts of yeasts and molds were observed in the samples containing natamycin, but nonsignificant differences between products were observed. In conclusion, SCW:WPI cheese coatings can successfully substitute commercial coatings with the advantage of being edible packaging materials manufactured with by-products.
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The removal of per- and polyfluoroalkyl substance (PFAS) pollution from the environment is a globally pressing issue, due to some PFAS' recalcitrant, bioaccumulative, and carcinogenic nature. Destruction via ultrasonic waves (sonolysis) is a promising contender for industrialisation due to; moderate power consumption, applicability to several PFAS and sample types, and limited by-products. Liquid flow rate through an ultrasonic reactor can affect the size, shape, and spatial distribution of ultrasonic cavities and hence their chemical activity. Such effects have not been studied during PFAS sonolysis, and temporal effects have not been studied much beyond the reactant concentration. Here, the effects of varying recirculating flow rate on the ultrasonic defluorination of perfluorooctane sulfonic acid (PFOS) and implications for industrial scale up are presented. Under the ultrasonic power (200â¯Wâ¯L-1, 2.27â¯Wâ¯cm-2) and frequency (410â¯kHz) used, flow rates of 79 and 214â¯mlâ¯min-1 enhanced defluorination up to 14â¯% during 30â¯min of treatment. However, these effects were temporal and most significant in the initial minutes of treatment. This indicated a dynamic bubble size distribution which stabilised after around 15â¯min. Defluorination rates of PFOS were compared with measured potassium iodide dosimetry, calorimetry, sonoluminescence (SL), and sonochemiluminescence (SCL). Flow rates which enhanced defluorination correlated moderately with enhanced SCL and negatively impacted SL, calorimetry, and dosimetry. Effects were attributed to perturbed cavity surfaces, leading to asymmetric cavity collapse, and the possibility of enhanced solvated electron production/interaction. SL, SCL, dosimetry, and calorimetric measurements were also temporal, and each showed different times to equilibrate. Flow rates of 439 and 889â¯mlâ¯min-1 returned all sonochemical measurements to the levels without flow, likely due to continued collapse temperature quenching by furthered bubble asymmetry. Flow also enhanced reactor cooling, which is significant for industrial temperature control. The pump energy consumed was small (≈1.9â¯%) compared to that of the amplifier and chiller, hence, PFOS defluorination was more cost-effective using flow. However, the effect may be limited for the longer treatment times needed for environmental remediation.
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Membrane filtration technologies are the best available tools to manage dairy byproducts such as cheese whey, allowing for the selective concentration of its specific components, namely proteins. Their acceptable costs and ease of operation make them suitable for application by small/medium-scale dairy plants. The aim of this work is the development of new synbiotic kefir products based on sheep and goat liquid whey concentrates (LWC) obtained by ultrafiltration. Four formulations for each LWC based on a commercial kefir starter or traditional kefir, without or with the addition of a probiotic culture, were produced. The physicochemical, microbiological, and sensory properties of the samples were determined. Membrane process parameters indicated that ultrafiltration can be applied for obtaining LWCs in small/medium scale dairy plants with high protein concentration (16.4% for sheep and 7.8% for goats). Sheep kefirs showed a solid-like texture while goat kefirs were liquid. All samples presented counts of lactic acid bacteria higher than log 7 CFU/mL, indicating the good adaptation of microorganisms to the matrixes. Further work must be undertaken in order to improve the acceptability of the products. It could be concluded that small/medium-scale dairy plants can use ultrafiltration equipment to valorize sheep's and goat's cheese whey-producing synbiotic kefirs.
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The term 'superfoods', used frequently with marketing purposes, is usually associated with foodstuffs with beneficial health properties. 'Superfoods' appears in many information sources, including digital media. The information they provide is easily accessible for consumers through Internet search engines. The objective of this work is to investigate the data that web pages offer to consumers and their accuracy according to current scientific knowledge. The two main search engines were utilized for English language websites search, introducing the term 'superfoods'. In total, 124 search results were found. After applying the selection criteria, 45 web pages were studied. A total of 136 foods were considered as 'superfoods' by sites; 10 of them (kale, spinach, salmon, blueberries, avocado, chia, walnuts, beans, fermented milks and garlic) were mentioned on at least 15 sites. Nutritional and healthy properties displayed on sites were compared to scientific information. In conclusion, websites present the information in a very simplified manner and it is generally not wrong. However, they should offer to consumers comprehensible information without raising false expectations regarding health benefits. In any case, 'superfoods' consumption can have salutary effects as part of a balanced diet.
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Chickpea flour is an affordable natural blend of starch, proteins, and lipids, which can create films with suitable properties as an eco-friendly packaging material. Nanoclays' incorporation into natural biopolymers enhances the barrier properties of the resulting nanocomposites, so they could improve the properties of flour films. The objective of this work was to assess the influence of three types of nanoclays (halloysite, bentonite, and Cloisite 20A) at two concentrations on the characteristics of chickpea flour films. In general terms, when the lowest dose (5%) was added, no or very slight significant differences with the control were observed in most parameters, except for thermal stability and opacity, which increased, and solubility, which decreased. At the highest concentration (10%), films containing any of the nanoclays demonstrated greater thermal stability, opacity, and rigidity while being less soluble than those without nanofillers. Bentonite exhibited superior film structure distribution compared to other nanoclays. At the highest concentration, it had the most significant impact on modifying the properties of chickpea flour films, increasing their tensile and puncture strengths while decreasing elasticity and water vapor permeability. The incorporation of nanoclays into chickpea flour films could be a useful technique to enhance their properties.
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Second cheese whey (SCW) is the by-product resulting from the manufacture of whey cheeses. In the present work, sheep (S) and goat (G) SCW concentrated by ultrafiltration (UF) were used in the production of ice creams. Concentrated liquid SCW samples with inulin added as a prebiotic were fermented with yoghurt, kefir and probiotic commercial cultures before being frozen in a horizontal frozen yoghurt freezer. The physicochemical, microbiological and sensory properties of the products were evaluated over 120 days of frozen storage. The products presented significant differences regarding these properties, specifically the higher total solids and protein contents of sheep's ice creams, which were higher compared to their goat ice cream counterparts. Sheep's ice creams also presented higher hardness and complex viscosity, which increased with storage. These ice creams also presented higher overrun and lower meltdown rates. The color parameters of the ice creams showed significant differences between formulations resulting from storage time. In all cases, Lactobacilli sp. cell counts were higher than log 6 CFU/g at the first week of storage. In the case of sheep's ice creams these values were maintained or increased until the 30th day, but decreased until the 60th day. Lactococci sp. counts surpassed log 7 CFU/g in all products, and these values were maintained until the end of storage, except in the case of G-Yoghurt and G-Kefir. Concerning the products containing probiotics, the sum of Lactococci sp. and Lactobacilli sp. counts was of the order log 8-9 CFU/g until the 60th day of storage, indicating that the probiotic characteristics of ice creams were maintained for at least 2 months. All products were well accepted by the consumer panel. Sheep's SCW ice creams were better rated regarding aroma, taste and texture. However, only the ranking test was able to differentiate preferences among formulations.
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BACKGROUND: The COVID-19 pandemic has affected the response capacity of the health care workforce, and health care professionals have been experiencing acute stress reactions since the beginning of the pandemic. In Spain, the first wave was particularly severe among the population and health care professionals, many of whom were infected. These professionals required initial psychological supports that were gradual and in line with their conditions. OBJECTIVE: In the early days of the pandemic in Spain (March 2020), this study aimed to design and validate a scale to measure acute stress experienced by the health care workforce during the care of patients with COVID-19: the Self-applied Acute Stress Scale (EASE). METHODS: Item development, scale development, and scale evaluation were considered. Qualitative research was conducted to produce the initial pool of items, assure their legibility, and assess the validity of the content. Internal consistency was calculated using Cronbach α and McDonald ω. Confirmatory factor analysis and the Mann-Whitney-Wilcoxon test were used to assess construct validity. Linear regression was applied to assess criterion validity. Back-translation methodology was used to translate the scale into Portuguese and English. RESULTS: A total of 228 health professionals from the Spanish public health system responded to the 10 items of the EASE scale. Internal consistency was .87 (McDonald ω). Goodness-of-fit indices confirmed a two-factor structure, explaining 55% of the variance. As expected, the highest level of stress was found among professionals working in health services where a higher number of deaths from COVID-19 occurred (P<.05). CONCLUSIONS: The EASE scale was shown to have adequate metric properties regarding consistency and construct validity. The EASE scale could be used to determine the levels of acute stress among the health care workforce in order to give them proportional support according to their needs during emergency conditions, such as the COVID-19 pandemic.
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INTRODUCTION: The tobacco-specific nitrosamines (TSNAs) are an important group of carcinogens found in tobacco and tobacco smoke. To describe and characterize the levels of TSNAs in the Population Assessment of Tobacco and Health (PATH) Study Wave 1 (2013-2014), we present four biomarkers of TSNA exposure: N'-nitrosonornicotine, N'-nitrosoanabasine, N'-nitrosoanatabine, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) which is the primary urinary metabolite of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. METHODS: We measured total TSNAs in 11 522 adults who provided urine using automated solid-phase extraction coupled to isotope dilution liquid chromatography-tandem mass spectrometry. After exclusions in this current analysis, we selected 11 004 NNAL results, 10 753 N'-nitrosonornicotine results, 10 919 N'-nitrosoanatabine results, and 10 996 N'-nitrosoanabasine results for data analysis. Geometric means and correlations were calculated using SAS and SUDAAN. RESULTS: TSNA concentrations were associated with choice of tobacco product and frequency of use. Among established, every day, exclusive tobacco product users, the geometric mean urinary NNAL concentration was highest for smokeless tobacco users (993.3; 95% confidence interval [CI: 839.2, 1147.3] ng/g creatinine), followed by all types of combustible tobacco product users (285.4; 95% CI: [267.9, 303.0] ng/g creatinine), poly tobacco users (278.6; 95% CI: [254.9, 302.2] ng/g creatinine), and e-cigarette product users (6.3; 95% CI: [4.7, 7.9] ng/g creatinine). TSNA concentrations were higher in every day users than in intermittent users for all the tobacco product groups. Among single product users, exposure to TSNAs differed by sex, age, race/ethnicity, and education. Urinary TSNAs and nicotine metabolite biomarkers were also highly correlated. CONCLUSIONS: We have provided PATH Study estimates of TSNA exposure among US adult users of a variety of tobacco products. These data can inform future tobacco product and human exposure evaluations and related regulatory activities.
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Biomarcadores/orina , Nitrosaminas/orina , Uso de Tabaco/epidemiología , Uso de Tabaco/orina , Adolescente , Adulto , Carcinógenos/análisis , Femenino , Humanos , Estudios Longitudinales , Masculino , Estados Unidos/epidemiología , Adulto JovenRESUMEN
The use of flours as a material for biopolymer-based film preparation has gained interest due to the fact that they are a natural mixture of compatible macromolecules and due to their low cost. Chickpea flour shows a promising composition for the development of edible films. The aim of this study was to characterize and evaluate the properties of chickpea flour films as affected by pH (7 or 10) and plasticizer concentration (1% or 3% w/v) of film-forming solutions. Water vapor permeability, solubility, color, opacity, mechanical properties, thermal stability, structural changes by Fourier transform infrared analysis, and microstructure of the films were determined. Glycerol content and pH influenced chickpea flour film properties, microstructure and structural organization; interactions were also observed. The 1% glycerol films showed lower water vapor permeability, thickness, radical scavenging capacity, elongation at break and puncture deformation, and higher dry matter content, swelling, opacity, elastic modulus, and tensile and puncture strengths than 3% glycerol films. Film-forming solutions at pH 10 produced films with higher thickness and swelling, and were greener than those from solutions at neutral pH. The changes were more intense in 1% glycerol films. Glycerol concentration and pH could be combined in order to obtain chickpea flour films with different properties according to different food packaging requirements.
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Cicer/química , Plastificantes/química , Biopolímeros/química , Módulo de Elasticidad , Harina , Embalaje de Alimentos/métodos , Glicerol/química , Concentración de Iones de Hidrógeno , Permeabilidad , Solubilidad , Vapor , Agua/químicaRESUMEN
The effects of different whey protein concentrate coating formulations (with or without glycerol or sorbitol in two proportions) on frozen Atlantic salmon quality parameters were evaluated. The influence of the moment of coating application (before or after freezing) was also studied. The coating application after freezing increased the thaw yield, decreased the drip loss, and modified colour parameters of frozen and thawed fillets, in comparison with application before freezing. The moment of coating also influenced the colour of cooked fish fillets. The type of plasticiser affects the colour of thawed and cooked samples, but not the colour of frozen samples. The protein coatings delayed lipid oxidation of salmon fillets, providing better protection against it than water glazing, and this effect was more pronounced when glycerol instead of sorbitol was used in the coating formulation. WPC+glycerol (1:1) coating was the best for frozen Atlantic salmon protection. The sensory properties of salmon fillets were not modified by the use of this coating.
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In the northwest of Spain, dry-cured pork forelegs are eaten after a process in which they are desalted and boiled. The effects of this culinary practice on the composition (mainly in relation to the lipids) of the external and internal muscles of dry-cured forelegs were studied. The dry-cured pork forelegs after culinary treatment showed a dry matter content of 46-47%, in both internal and external muscles. The culinary treatment caused decrease of ash, NaCl and cholesterol contents and increase of lipid and protein contents. Nitrates and nitrites decreased only in external muscles. No significant changes were observed in the TBA values. The culinary treatment caused significant decreases in phospholipids and significant increases in free fatty acids. The free fatty acids of boiled desalted dry-cured forelegs showed higher PUFA proportions than dry-cured forelegs, mainly in external muscles.