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1.
Methods ; 225: 100-105, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38565390

RESUMO

The development of reliable probe technology for the detection of bisulfite (HSO3-) in situ in food and biological samples is contributing significantly to food quality and safety assurance as well as community health. In this work, a responsive probe, EHDI, is developed for ratiometric fluorescence detection of HSO3- in aqueous solution, meat samples, and living cells. The probe is designed based on the HSO3- triggered 1,4-addition of electron deficit C = C bond of EHDI. As a result of this specific 1,4-addition, the π-conjugation system was destructed, resulting in blue shifts of the emission from 687 to 440 nm and absorption from 577 to 355 nm. The probe has good water solubility, high sensitivity and selectivity, allowing it to be used for imaging of HSO3- internalization and production endogenously. The capability of probe EHDI for HSO3- was then validated by traditional HPLC technology, enabling accurately detect HSO3- in beef samples. The successful development of this probe thus offers a new tool for investigating HSO3- in situ in food and biological conditions.


Assuntos
Corantes Fluorescentes , Carne , Sulfitos , Sulfitos/análise , Sulfitos/química , Corantes Fluorescentes/química , Animais , Humanos , Carne/análise , Espectrometria de Fluorescência/métodos , Bovinos , Carne Vermelha/análise
2.
Methods ; 214: 1-7, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37075873

RESUMO

Increasing awareness of the health and environment impacts of the antibiotics misuse or overuse, such as tetracycline (TC) in treatment or prevention of infections and diseases, has driven the development of robust methods for their detection in biological, environmental and food systems. In this work, we report the development of a new europium(III) complex functionalized silica nanoprobe (SiNPs-Eu3+) for highly sensitive and selective detection of TC residue in aqueous solution and food samples (milk and meat). The nanoprobe is developed by immobilization of Eu3+ ion onto the surface of silica nanoparticles (SiNPs) as the emitter and TC recognition unit. The ß-diketone configuration of TC can further coordinate with Eu3+ steadily on the surface of nanoprobe, facilitating the absorption of light excitation for Eu3+ emitter activation and luminescence "off-on" response. The dose-dependent luminescence enhancement of SiNPs-Eu3+ nanoprobe exhibits good linearities, allowing the quantitative detection of TC. The SiNPs-Eu3+ nanoprobe shows high sensitivity and selectivity for TC detection in buffer solution. Time resolved luminescence analysis enables the elimination of autofluorescence and light scattering for highly sensitive detection of TC in milk and pork mince with high accuracy and precision. The successful development of SiNPs-Eu3+ nanoprobe is anticipated to provide a rapid, economic, and robust approach for TC detection in real world samples.


Assuntos
Európio , Luminescência , Európio/análise , Európio/química , Dióxido de Silício , Tetraciclina/análise , Tetraciclina/química , Antibacterianos
3.
Molecules ; 28(6)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36985798

RESUMO

Kakadu plum (Terminalia ferdinandiana), endemic to Australia, is growing in popularity due to its high levels of vitamin C and strong antioxidant properties. In this study, Kakadu plum fruit powder was used as a functional food ingredient with other plant materials to develop value-added products to enhance their nutritional and commercial value. The present study determined the bioactive properties of nine products, including three Kakadu plum fruit powder samples produced from different processing batches and five Kakadu plum-blended products. Vitamin C, the total phenolic content, and the ellagic acid content were determined. Bioactive properties such as antioxidant, antidiabetic, and antimicrobial assays were also performed. Cytotoxicity was tested to obtain more specific product information regarding food safety. Kakadu plum-blended products showed lower cytotoxicity and lower bioactive properties (antioxidant and antibacterial activities) in comparison to Kakadu plum powder. However, overall, most of the bioactive properties were shown to be higher in the blends when compared with the commercial blueberry powder as a benchmark antioxidant product. Therefore, there is great potential for Kakadu plum to contribute to the growing functional food and ingredient markets.


Assuntos
Antioxidantes , Prunus domestica , Antioxidantes/farmacologia , Pós , Ácido Ascórbico , Fenóis/farmacologia , Fenóis/análise , Vitaminas , Frutas/química
4.
Molecules ; 28(4)2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36838596

RESUMO

Pleiogynium timoriense, commonly known as Burdekin plum (BP), is among many Australian native plants traditionally used by Indigenous people. However, only limited information is available on the nutritional and sensory quality of BP grown in Australia as well as its changes during storage. Therefore, this study evaluated the quality of BP during one week of ambient storage (temperature 21 °C, humidity 69%). Proximate analysis revealed a relatively high dietary fiber content in BP (7-10 g/100 g FW). A significant reduction in fruit weight and firmness (15-30% and 60-90%, respectively) with distinguishable changes in flesh color (ΔE > 3) and an increase in total soluble solids (from 11 to 21 °Brix) could be observed during storage. The vitamin C and folate contents in BP ranged from 29 to 59 mg/100g FW and 0.3 to 5.9 µg/100g FW, respectively, after harvesting. A total phenolic content of up to 20 mg GAE/g FW and ferric reducing antioxidant power of up to 400 µmol Fe2+/g FW in BP indicate a strong antioxidant capacity. In total, 34 individual phenolic compounds were tentatively identified in BP including cyanidin 3-galactoside, ellagic acid and gallotannins as the main phenolics. Principle component analysis (PCA) of the quantified phenolics indicated that tree to tree variation had a bigger impact on the phenolic composition of BP than ambient storage. Sensory evaluation also revealed the diversity in aroma, appearance, texture, flavor and aftertaste of BP. The results of this study provide crucial information for consumers, growers and food processors.


Assuntos
Anacardiaceae , Prunus domestica , Humanos , Antioxidantes , Austrália , Ácido Ascórbico , Frutas
5.
Molecules ; 28(10)2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37241743

RESUMO

Halophytes are considered emerging functional foods as they are high in protein, minerals, and trace elements, although studies investigating halophyte digestibility, bioaccessibility, and intestinal absorption are limited. Therefore, this study investigated the in vitro protein digestibility, bioaccessibility and intestinal absorption of minerals and trace elements in saltbush and samphire, two important Australian indigenous halophytes. The total amino acid contents of samphire and saltbush were 42.5 and 87.3 mg/g DW, and even though saltbush had a higher total protein content overall, the in vitro digestibility of samphire protein was higher than the saltbush protein. The in vitro bioaccessibility of Mg, Fe, and Zn was higher in freeze-dried halophyte powder compared to the halophyte test food, suggesting that the food matrix has a significant impact on mineral and trace element bioaccessibility. However, the samphire test food digesta had the highest intestinal Fe absorption rate, whereas the saltbush digesta exhibited the lowest (37.7 vs. 8.9 ng/mL ferritin). The present study provides crucial data about the digestive "fate" of halophyte protein, minerals, and trace elements and increases the understanding of these underutilized indigenous edible plants as future functional foods.


Assuntos
Plantas Tolerantes a Sal , Oligoelementos , Austrália , Absorção Intestinal , Minerais , Plantas Tolerantes a Sal/química , Oligoelementos/análise
6.
Crit Rev Food Sci Nutr ; 62(10): 2845-2853, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33401934

RESUMO

By 2050, the global population is projected to be in excess of nine billion people. This will result in an increased burden and stress on the food production systems, particularly in adjustments to several stages of the value chain that will require improvements and/or modifications in their effectiveness such as reducing waste, adapting to climate change, food security, and health. Disruptions such as digital agriculture, digital food, food agility, big data, have been utilized to characterize the changes in the way agro-food systems evolve and function, as well as in the approach they have been analyzed, measured, and monitored. It has been long recognized that the food industry is considered as a data driven enterprise. These characteristics are very important as the food industry becomes global and sustainable. The food industry is currently undergoing significant changes, and with this, challenges are occurring. These challenges are brought about from the food chains, climate changes, and the ability to be resilient in the production of food. Furthermore, health and cultural changes to food are occurring, where the diseases of obesity, diabetes, and aging in the population will continue to change the consumer's patterns and choices; whereby the consumer will be persuaded to choose and eat healthy and more nutritious foods. Indeed, the cultural awareness and social innovation to prevent food waste and therefore improve food security and sustainability will also prove to further complexities. This short review will briefly discuss some of the forefront issues in food value chains with a focus on using technology.


Assuntos
Alimentos , Eliminação de Resíduos , Agricultura , Mudança Climática , Abastecimento de Alimentos , Humanos
7.
Molecules ; 27(6)2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-35335263

RESUMO

Prior to consumption, African pumpkin leaves (Momordica balsamina L.) are generally cooked. In this study, the effects of common household cooking methods (boiling, steaming, microwaving, stir-frying) on bioactive metabolites, carotenoids, antioxidant activity, antinutrients and inhibitory effects on α-glucosidase and α-amylase activities were examined. A set of 14 bioactive metabolites were identified in raw and cooked African leaves using UPLC-QTOF/MS. The results showed that the four different types of household cooking methods had different effects on the bioactive metabolomics profile of African pumpkin leaves. In comparison to raw leaves and leaves cooked in other methods, the concentrations of six phenolic compounds, rutin, cryptochlorogenic acid (4-caffeoylquinic acid), pseudolaroside A, isorhamnetin 3-O-robinoside, quercetin 3-galactoside, and trans-4-feruloylquinic acid, were highest in stir-fried leaves. Of all household cooking methods tested, stir-frying increased the content of lutein, ß-carotene, and zeaxanthin by 60.00%, 146.15%, and 123.51%, respectively. Moreover, stir-frying African pumpkin leaves increased the antioxidant activity (DPPH and ABTS) and the inhibition of α-glucosidase and α-amylase. Compared to all four methods of household cooking, stir-frying reduced the antinutritive compounds compared to raw leaves. This work provides useful information to the consumers on the selection of suitable cooking methods for African pumpkin leaves.


Assuntos
Cucurbita , Momordica , Carotenoides/análise , Carotenoides/farmacologia , Culinária/métodos , Folhas de Planta/química
8.
Sensors (Basel) ; 21(4)2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33670523

RESUMO

Kakadu plum (KP; Terminalia ferdinandiana Exell, Combretaceae) is an emergent indigenous fruit originating from Northern Australia, with valuable health and nutritional characteristics and properties (e.g., high levels of vitamin C and ellagic acid). In recent years, the utilization of handheld NIR instruments has allowed for the in situ quantification of a wide range of bioactive compounds in fruit and vegetables. The objective of this study was to evaluate the ability of a handheld NIR spectrophotometer to measure vitamin C and ellagic acid in wild harvested KP fruit samples. Whole and pureed fruit samples were collected from two locations in the Kimberley region (Western Australia, Australia) and were analysed using both reference and NIR methods. The standard error in cross validation (SECV) and the residual predictive deviation (RPD) values were 1.81% dry matter (DM) with an RPD of 2.1, and 3.8 mg g-1 DM with an RPD of 1.9 for the prediction of vitamin C and ellagic acid, respectively, in whole KP fruit. The SECV and RPD values were 1.73% DM with an RPD of 2.2, and 5.6 mg g-1 DM with an RPD of 1.3 for the prediction of vitamin C and ellagic acid, respectively, in powdered KP samples. The results of this study demonstrated the ability of a handheld NIR instrument to predict vitamin C and ellagic acid in whole and pureed KP fruit samples. Although the RPD values obtained were not considered adequate to quantify these bioactive compounds (e.g., analytical quantification), this technique can be used as a rapid tool to screen vitamin C in KP fruit samples for high and low quality vitamin C.


Assuntos
Prunus domestica , Terminalia , Ácido Ascórbico , Austrália , Frutas
9.
Molecules ; 26(7)2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33810352

RESUMO

In recent times, the popularity of adding value to under-utilized legumes have increased to enhance their use for human consumption. Acacia seed (AS) is an underutilized legume with over 40 edible species found in Australia. The study aimed to qualitatively characterize the chemical composition of 14 common edible AS species from 27 regions in Australia using mid-infrared (MIR) spectroscopy as a rapid tool. Raw and roasted (180 °C, 5, 7, and 9 min) AS flour were analysed using MIR spectroscopy. The wavenumbers (1045 cm-1, 1641 cm-1, and 2852-2926 cm-1) in the MIR spectra show the main components in the AS samples. Principal component analysis (PCA) of the MIR data displayed the clustering of samples according to species and roasting treatment. However, regional differences within the same AS species have less of an effect on the components, as shown in the PCA plot. Statistical analysis of absorbance at specific wavenumbers showed that roasting significantly (p < 0.05) reduced the compositions of some of the AS species. The results provided a foundation for hypothesizing the compositional similarity and/or differences among AS species before and after roasting.


Assuntos
Acacia/química , Valor Nutritivo , Sementes/química , Acacia/classificação , Austrália , Culinária , Análise de Componente Principal , Espectrofotometria Infravermelho
10.
J Sci Food Agric ; 101(12): 5132-5141, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33608906

RESUMO

BACKGROUND: Terminalia ferdinandiana, common name Kakadu plum (KP), fruit is a valuable source of vitamin C, and its concentration can be used as a quality index of KP products, such as dried fruit powder. The present study investigated the effects of two drying methods (freeze-drying and oven-drying) and the addition of maltodextrin (0-25%) on vitamin C, Maillard products, and overall quality of KP fruit powder. RESULTS: Freeze-drying was a better dehydration technique than oven-drying in retaining vitamin C, reducing the formation of non-enzymatic browning and oxidation products, and improving powder colour (P < 0.05). Non-enzymatic browning products (furfural and 5-hydroxymethyl furfural) were generated in the oven-dried samples as a function of heating and high water activity. Maltodextrin acted as a vitamin C stabilizer in protecting vitamin C from oxidation, and significantly improved the colour attributes of the final dry products. Incorporation of 10-15% maltodextrin could reduce the percentage loss of vitamin C from 8.1% to 3.4% and 18.9% to 11.4% (compared with the control) during freeze-drying and oven-drying, respectively. Scanning electron micrographs revealed differences in the microstructures of the KP powder processed by the two drying methods with different levels of maltodextrin. Multivariate data analysis (principal component analysis) showed separation between the oven-dried and freeze-dried samples, and also suggested that addition of maltodextrin of 7.5-10% and 10-15% are effective for preserving vitamin C and other quality properties of the freeze- and oven-dried KP powder samples, respectively. CONCLUSION: The results obtained are important for the KP industry, including Indigenous enterprises, in selecting the most appropriate drying method for KP fruit in terms of quality and sustainability. © 2021 Society of Chemical Industry.


Assuntos
Ácido Ascórbico/análise , Manipulação de Alimentos/métodos , Polissacarídeos/análise , Terminalia/química , Austrália , Ingredientes de Alimentos/análise , Liofilização , Frutas/química , Temperatura Alta , Pós/química
11.
J Sci Food Agric ; 101(11): 4681-4690, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33491776

RESUMO

BACKGROUND: Acacia seed (AS) is an underutilized legume widely distributed in the world, with majority of the species (>70%) found in Australia. Generally, the seeds are not only rich in protein, dietary fibre and potassium, but also possess anti-nutritional compounds. In recent years, there have been an increase in the cultivation of some Australian acacia species such as Acacia victoriae, Acacia cowleana and Acacia coriacea from different regions. However, there is limited information on the composition, anti-nutrients, antioxidant and functional properties of flour from these widely grown Australian AS species. Thus, the present study aimed to assess the properties of these Australian AS species from different geographical regions. RESULTS: The A. cowleana and A. coriacea were characterized by high protein, fat, potassium and soluble carbohydrate. However, higher starch and fibre contents were present in A. victoriae. Greater amounts of anti-nutrients, total phenolics and flavonoids were found in A. cowleana and A. coriacea seeds, whereas A. victoriae had higher 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity. A. victoriae and A. coriacea demonstrated the highest water absorption and solubility index, respectively. However, A. cowleana showed the highest oil absorption index. There was less variation in the composition and properties within species from different regions. CONCLUSION: All samples showed promising nutritional characteristics, although with sufficient diversity to indicate that Australian acacia seeds can be utilized to develop a range of new (functional) food products. Overall, the information obtained will help the food industries with the selection of AS species for food application.


Assuntos
Acacia/química , Antioxidantes/análise , Acacia/classificação , Austrália , Fibras na Dieta/análise , Flavonoides/análise , Farinha/análise , Valor Nutritivo , Fenóis/análise , Sementes/química
12.
J Sci Food Agric ; 101(8): 3208-3213, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33215708

RESUMO

BACKGROUND: The objective of this study was to evaluate the feasibility of using either mid-infrared (MIR) or near-infrared (NIR) spectroscopy to predict the vitamin C content in Kakadu plum (Terminalia ferdinandiana Exell, Combretaceae) powder samples. Vitamin C is the main and quality-determining bioactive compound in Kakadu plum (KP). Kakadu plum powder samples were analyzed by ultra-performance liquid chromatography coupled to a photodiode array detector (UPLC-PDA) and scanned using both MIR and NIR spectroscopy. RESULTS: The coefficient of determination (R2 ) and the standard error in cross validation (SECV) for vitamin C were 0.93 and 1811 mg 100 g dry weight (DW) and 0.91 and 1839 mg 100 g DW using MIR and NIR spectroscopy, respectively. The coefficient of correlation and the standard error of prediction (SEP) obtained using the independent set (n = 5) were 0.65 (SEP: 2367 mg 100 g DW) and 0.73 (SEP: 4773 mg 100 g DW) using MIR and NIR spectroscopy, respectively. CONCLUSIONS: The results obtained in this study clearly showed that it is possible to calibrate IR spectroscopic instruments for the measurement of vitamin C in KP plum powder samples. Mid-infrared spectroscopy showed the most promising results; however, Fourier transform near-infrared (FTNIR) spectroscopy also produced models capable of good quantification of this important bioactive compound and vitamin. These findings are promising in terms of using high-throughput IR spectroscopy as a routine technology to determine vitamin C in plant-based foods and derived products. © 2020 Society of Chemical Industry.


Assuntos
Ácido Ascórbico/análise , Análise de Alimentos/métodos , Extratos Vegetais/análise , Terminalia/química , Pós/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos
13.
Molecules ; 25(6)2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32183223

RESUMO

Chinese cabbage (Brassica rapa L. subsp. chinensis) and Nightshade (Solanum retroflexum are popular traditional leafy vegetables consumed predominantly by rural Africans. Sun drying is adopted as a traditional method of postharvest preservation to store theses leaves during off seasons. The influence of different types of postharvest processing treatments, such as conventional oven drying, solar cabinet drying, sun drying and freeze drying, on the changes on colour properties and antioxidant components were investigated. Freeze-drying retained the ascorbic acid content, antioxidant activities, total chlorophyll content, green colour by reducing the colour difference (∆E). With regard to Chinese cabbage and Nightshade leaves, sun and microwave drying respectively had the most negative impact on all the identified phenolic compounds. The OPLS-DA and the UPLC-QTOF/MS and chemometric approach showed kaempferol-3-O-sophoroside, kaempferol-3-sophorotrioside-7-glucoside and hydroxyoctadecenedioic acid as the markers responsible for the separation of sun-dried samples from the other drying treatments in Chinese cabbage. Sinapoyl malate was not detected in sun-dried samples. Caffeoylmalic acid was identified as the marker compound to separate the other drying treatments from the microwave dried samples of Nightshade leaves. Trihydroxyoctadecadiene derivative and hydroxyoctadecanedioic acid were detected in microwaved samples. Due to the cost effectiveness, solar dryer cabinet treatment was recommended for drying both vegetables. The proximate analysis of solar dried functional powder of Chinese cabbage and Nightshade vegetables demonstrated higher contents of protein and dietary fibre.


Assuntos
Antioxidantes/metabolismo , Brassica rapa/metabolismo , Dessecação/métodos , Metaboloma , Fenóis/metabolismo , Solanum/metabolismo , Ácido Ascórbico/metabolismo , Biomarcadores/metabolismo , Flavonoides/metabolismo , Glicosídeos/metabolismo , Pigmentos Biológicos/metabolismo , Folhas de Planta/metabolismo , Análise de Componente Principal , Saponinas/metabolismo
14.
Compr Rev Food Sci Food Saf ; 19(4): 1727-1759, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33337095

RESUMO

Consumer awareness on the side effects of chemical preservatives has increased the demand for natural preservation technologies. An efficient and sustainable alternative to current conventional preservation techniques should guarantee food safety and retain its quality with minimal side effects. Photosensitization, utilizing light and a natural photosensitizer, has been postulated as a viable and green alternative to the current conventional preservation techniques. The potential of curcumin as a natural photosensitizer is reviewed in this paper as a practical guide to develop a safe and effective decontamination tool for industrial use. The fundamentals of the photosensitization mechanism are discussed, with the main emphasis on the natural photosensitizer, curcumin, and its application to inactivate microorganisms as well as to enhance the shelf life of foods. Photosensitization has shown promising results in inactivating a wide spectrum of microorganisms with no reported microbial resistance due to its particular lethal mode of targeting nucleic acids. Curcumin as a natural photosensitizer has recently been investigated and demonstrated efficacy in decontamination and delaying spoilage. Moreover, studies have shown the beneficial impact of an appropriate encapsulation technique to enhance the cellular uptake of photosensitizers, and therefore, the phototoxicity. Further studies relating to improved delivery of natural photosensitizers with inherent poor solubility should be conducted. Also, detailed studies on various food products are warranted to better understand the impact of encapsulation on curcumin photophysical properties, photo-driven release mechanism, and nutritional and organoleptic properties of treated foods.


Assuntos
Curcumina/farmacologia , Luz , Fármacos Fotossensibilizantes/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/efeitos da radiação , Curcumina/química , Sistemas de Liberação de Medicamentos , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Inocuidade dos Alimentos , Fungos/efeitos dos fármacos , Fungos/efeitos da radiação
15.
Compr Rev Food Sci Food Saf ; 19(1): 21-43, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-33319524

RESUMO

The popularity of adding value to indigenous plant protein sources has increased due to the rise in the world population, high costs of animal protein as compared to plant proteins, and an increase in the consumer awareness of the nutritional and functional roles of dietary plant protein. Seeds of acacia plants (containing over 1,350 species) have considerable amount of protein (18.25% to 35.5%) and nutritionists have shown great interest in assessing the quality and functionality of proteins from these protein-rich plants. In this review, the overall nutritional and health-promoting properties of acacia seed (AS) species are introduced. Extraction, quality, and functional properties of proteins from different AS species are discussed. Furthermore, anti-nutritional components and protease inhibitors present in AS species and the effects of processing methods applied to lower the levels of anti-nutrients are also discussed. Previous applications of AS in food formulations are highlighted. This review aims to provide updated findings that have been reported on AS proteins and to highlight areas for further studies in order to increase the utilization potential of the seeds.


Assuntos
Acacia/química , Valor Nutritivo , Proteínas de Plantas/análise , Sementes/química , Manipulação de Alimentos/métodos , Inibidores de Proteases/análise
16.
Small ; 15(2): e1803712, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30548763

RESUMO

Responsive nanoprobes play an important role in bioassay and bioimaging, early diagnosis of diseases and treatment monitoring. Herein, a upconversional nanoparticle (UCNP)-based nanoprobe, Ru@UCNPs, for specific sensing and imaging of hypochlorous acid (HOCl) is reported. This Ru@UCNP nanoprobe consists of two functional components,, i.e., NaYF4 :Yb, Tm UCNPs that can convert near infrared light-to-visible light as the energy donor, and a HOCl-responsive ruthenium(II) complex [Ru(bpy)2 (DNCH-bpy)](PF6 )2 (Ru-DNPH) as the energy acceptor and also the upconversion luminescence (UCL) quencher. Within this luminescence resonance energy transfer nanoprobe system, the UCL OFF-ON emission is triggered specifically by HOCl. This triggering reaction enables the detection of HOCl in aqueous solution and biological systems. As an example of applications, the Ru@UCNPs nanoprobe is loaded onto test papers for semiquantitative HOCl detection without any interference from the background fluorescence. The application of Ru@UCNPs for background-free detection and visualization of HOCl in cells and mice is successfully demonstrated. This research has thus shown that Ru@UCNPs is a selective HOCl-responsive nanoprobe, providing a new way to detect HOCl and a new strategy to develop novel nanoprobes for in situ detection of various biomarkers in cells and early disgnosis of animal diseases.


Assuntos
Diagnóstico por Imagem/métodos , Ácido Hipocloroso/química , Nanopartículas/química , Animais , Camundongos , Camundongos Nus , Rutênio/química
17.
Food Microbiol ; 82: 82-88, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31027823

RESUMO

Different methods have been applied in controlling contamination of foods and feeds by the carcinogenic fungal toxin, aflatoxin, but nevertheless the problem remains pervasive in developing countries. Curcumin is a natural polyphenolic compound from the spice turmeric (Curcuma longa L.) that has been identified as an efficient photosensitiser for inactivation of Aspergillus flavus conidia. Curcumin mediated photoinactivation of A. flavus has revealed the potential of this technology to be an effective method for reducing population density of the aflatoxin-producing fungus in foods. This study demonstrates the influence of pH and temperature on efficiency of photoinactivation of the fungus and how treating spore-contaminated maize kernels affects aflatoxin production. The results show the efficiency of curcumin mediated photoinactivation of fungal conidia and hyphae were not affected by temperatures between 15 and 35 °C or pH range of 1.5-9.0. The production of aflatoxin B1 was significantly lower (p < 0.05), with an average of 82.4 µg/kg as compared to up to 305.9 µg/kg observed in untreated maize kept under similar conditions. The results of this study indicate that curcumin mediated photosensitization can potentially be applied under simple environmental conditions to achieve significant reduction of post-harvest contamination of aflatoxin B1 in maize.


Assuntos
Aflatoxina B1/metabolismo , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/efeitos da radiação , Curcumina/farmacologia , Transtornos de Fotossensibilidade , Zea mays/microbiologia , Concentração de Íons de Hidrogênio , Hifas/efeitos dos fármacos , Hifas/efeitos da radiação , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/efeitos da radiação , Temperatura
18.
Foods ; 13(6)2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38540930

RESUMO

Due to spoilage microflora and browning, minimally processed fresh-cut fruits have a short shelf life, and over the years, studies have shown the potential of using edible coatings to extend the shelf life and improve the safety of fresh-cut fruits. Recently, there has been a rise in research on the incorporation of probiotics in edible coatings due to the bespoke health and biopreservation benefits they impart. Therefore, in this study, lactobacillus strains (Lactiplantibacillus plantarum 75 and Bifidobacterium longum) were incorporated into a xanthan edible coating to enhance color retention, sensory properties, antioxidant retention (ascorbic acid, carotenoids, total phenols), and antioxidant activity (FRAP antioxidant power, ABTS scavenger activity) of fresh-cut cantaloupes and honeydew cucumis melo L. melons during cold storage at 5 C and 85% RH for five days. The edible coating was prepared by mixing 0.5% xanthan gum, 1% glycerol, and 2% citric acid solution with L. plantarum 75 (LAB 75) and Bifidobacterium longum bacteria separately, and the final lab count for each strain was made to be 8.0 log CFU/mL. Stable probiotic coatings with ζ-potential of between -39.7 and -51.4 mV and a PdI of 1 were developed, and the incorporation of the probiotic bacteria into the coating was justified using FTIR analysis. The probiotic coatings showed a typical pseudoplastic behavior, in which the viscosity curves fall as the shear rate increases. Thermal stability analysis showed a continuous and multi-step weight reduction in this work, illustrating how the edible coating components interact. The survival of both Lactobacillus strains was recorded on day 5. Both freshly cut melons coated with xanthan and loaded with Lactobacillus strains retained a sufficient quantity of probiotics at the end of storage, while L. plantarum 75 (7 log CFU/g for cantaloupe and 8 log CFU/g for honeydew) retained the highest viability compared to B. longum (6 log CFU/g for cantaloupe and 7 log CFU/g for honeydew). In comparison to the coated and uncoated control samples, the inclusion of L. plantarum 75 in xanthan coatings significantly retained the color properties, pigments (total chlorophyll and carotenoids), ascorbic acid, total phenols, and antioxidant activity (FRAP, DPPH, and ABTS). The overall acceptability of fresh cuts of cantaloupe and honeydew melons coated with xanthan gum loaded with L. plantarum 75 was higher than that of other treatments. Thus, xanthan gum loaded with L. plantarum 75 coating is most suitable for reducing postharvest losses in fresh cuts of honeydew melons and cantaloupe, which will help preserve antioxidant and bioactive properties. The xanthan gum loaded with L. plantarum 75 coatings exhibited the highest preservation impact; therefore, it can be recommended for the fresh-cut industry.

19.
Food Chem ; 448: 139057, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38555694

RESUMO

Kakadu plum (Terminalia ferdinandiana) (KP) is an indigenous fruit used as a functional ingredient in powdered form. Three KP doses (1, 2.5 and 5 g) were digested in a dynamic in vitro gut digestion model over 48 h. Faecal water digests from the colonic reactors were assessed for total soluble polyphenols (TSP), ferric reducing antioxidant power (FRAP), phenolic metabolites and short-chain fatty acids (SCFAs). Effects of digests on cell viability were tested against Caco-2 intestinal and HepG2 hepatic cells. All doses of KP fermentation produced castalagin, corilagin, chebulagic acid, chebulinic acid, and gallic acid. TSP and FRAP significantly increased in 5 g KP digests at 0 and 48 h of fermentation. SCFA concentrations significantly increased after 48 h. Cytotoxic effects of 2.5 and 5 g KP digests diminished significantly after 12 h. Overall, colonic fermentation increased antioxidant activity and polyphenolic metabolites of 5 g KP powder for 48 h.

20.
J Food Sci ; 89(5): 2991-3005, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38571409

RESUMO

Increased salt (sodium chloride (NaCl)) consumption contributes to high blood pressure, increasing the risk of cardiovascular disease. Reducing the intake of NaCl could result in significant public health benefits. Australian grown halophytes are consumed traditionally by indigenous communities as food and medicine. The importance of halophytes has been recently "rediscovered" due to their salty taste and crunchy texture. This study aimed to assess the potential of Australian indigenous edible halophytes (AIEH) as salt substitutes. A benchtop test was carried out to establish a sensory lexicon of four important AIEH (samphire, seapurslane, seablite, and saltbush) and to select the most promising halophyte based on sensory attributes and nutritional composition. Samphire and saltbush, the most common and commercially important halophytes, were used as comparisons. Semolina was used to prepare the halophyte-based test food for the benchtop sensory study. Results of the formal sensory study showed that the growing location of samphire and saltbush can significantly affect their sensory attributes. Samphire had the most favorable sensory attributes and nutritional quality, with dry herb and bran aroma and flavor, whereas the saltbush test food preparations had herbaceous, minty dry wood, and green fruit aroma and flavor. The "optimal" concentration of added freeze-dried samphire/saltbush powder was determined based on the saltiness perception of the NaCl-semolina formulation (0.3% table salt equivalent to 1% samphire freeze-dried powder and 1.4%-2.0% saltbush freeze-dried powder, respectively). This study provided novel and crucial information on the potential use of AIEH as natural salt substitutes. PRACTICAL APPLICATION: There is an increasing demand for natural salt substitutes. Halophytes are salt tolerant plants that sustain in arid or semiarid areas and have the potential to be used as natural salt substitutes. To the best of our knowledge, this is the first study reporting the sensory profiles of four important Australian indigenous edible halophytes (samphire, seapurslane, seablite, and saltbush). This study also demonstrated how different growing locations can affect the sensory attributes of halophytes and subsequently their potential food applications. Our findings provide critical information and data to further study halophytes in the context of novel food applications.


Assuntos
Plantas Tolerantes a Sal , Paladar , Plantas Tolerantes a Sal/química , Austrália , Humanos , Valor Nutritivo , Cloreto de Sódio na Dieta/análise , Odorantes/análise
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