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Walnuts are among the commonly consumed oil nuts in the world. The nuts typically contain 40–70% oil, and are a rich source of fatty acids, phenolics, phytosterols, tocopherols and carotenoids. The...

Black walnut (Juglans nigra L.) is one of the most widely consumed nuts in the United States. The nut has been recognized for its unique, bold flavor, and used as a versatile food ingredient. The objective of this review is to summarize available research data pertaining to phytochemicals present in black walnut and their previously reported health-promoting properties. Black walnut is rich in phenolics and contains higher levels of phytosterols, unsaturated fatty acids and tocopherols than many other commonly consumed nuts. Dietary intervention of these constituents has been associated with a great number of disease-preventive properties. Black walnut has a potential to inhibit the release of proinflammatory mediators in vitro. Similarities in contents of unsaturated fatty acids and tocopherols between black walnut and English walnut suggest that black walnut consumption may produce beneficial effects on cardiovascular disease risks. In addition, the high level of γ-tocopherol in black walnut could make the nut a cancer-preventive option. Although evidence has shown black walnut kernel is a rich source of phytochemicals of potential importance to human health, there is a paucity of in vitro and in vivo studies on the bioactivities of these phytochemicals isolated from black walnut and the health-promoting properties of black walnut consumption. Clinical studies are needed to better understand the health benefits of black walnut.

Vietnam, a Southeast Asian country, has documented 1,515 polymerase chain reaction-positive confirmed coronavirus disease 2019 (COVID-19) cases with 35 deaths a year after the first infection recorded in Ha Noi on January 23, 2020. Half of the infected patients are at the age of 21 to 40 y. While numbers of infections in many countries in the region continue to surge, Vietnam is seeing decreases in the number of daily new cases. As a result of COVID-19 trajectory different from the other countries, as of April 23, 2020, Vietnam is no longer under lockdown and is slowly restarting its socioeconomic activities. This report aims to provide a summary of the COVID-19 situation and response to the pandemic in Vietnam.

Spent coffee ground (SCG) is a residue released during coffee brewing. Disposal of SCG is able to lead to a loss of bioactive constituents and have a negative impact upon the environment. This study aimed to explore fatty acids, bioactive phenolics, antioxidant and anti-aging potentials of SCG samples obtained from coffee shops in Ho Chi Minh city, Vietnam. The oil content of the SCG samples ranged from 6.3 to 10.5%, and linoleic (43%), palmitic (33.4%) and oleic (11%) acids were identified as major constituents of the oil. Chlorogenic acid was the most abundant phenolic acid examined (832.9���7657.7 ��g/g of dry weight), followed by ferulic acid (40.5���1041.7 ��g/g). Through anti-collagenase and anti-elastase assays, SCG showed a promising anti-aging activity, with IC50 values comparable with those of epigallocatechin gallate. The correlation analysis revealed gallic acid positively correlated with the free radical scavenging potential evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and the inhibitory effect on elastase. The results demonstrated that utilization of SCG prepared from Vietnamese coffee could open new avenues for food and cosmeceutical industry.

While many nations are struggling to slow the transmission rate of the coronavirus disease 2019 (COVID-19), Vietnam has seen no new locally acquired cases since April 16. After implementing 22 d of nationwide social distancing, on April 23, the government of Vietnam announced the easing of social distancing measures. This allows the country to restart its socio-economic activities in a gradual, prudent manner. Domestic tourism and exports of agricultural and anti-COVID-19 medical products take priority over the other sectors in this postpandemic economic recovery. Importantly, the country needs to stay vigilant on the fight against the disease to prevent a possibility of another outbreak.

Similar to other nations in the world, Vietnam has swiftly implemented measures to contain the spread of COVID-19, and these have been transforming many aspects of society. The country is showing resilience to fear, stress, and anxiety related to the COVID-19 pandemic. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

There has been an increasing number of consumer and food products sold on the market that contain various engineered nanomaterials (ENMs) such as silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs). These nanomaterials possess novel physical and chemical properties that can be used for wide applications in agriculture and food safety. However, current analytical methods to detect and measure ENMs are time-consuming, labor-intensive, and expensive. The objective of this study was to develop a novel, simple, rapid, and accurate method to detect AgNPs and AuNPs in consumer products using surface-enhanced Raman spectroscopy (SERS). SERS measurement was conducted to detect AgNPs and AuNPs using an effective Raman indicator, 4-aminothiophenol (pATP). The pATP can strongly bind onto nanoparticles, generating greatly enhanced Raman signals that can be used for measurement. The pATP was combined with Ag or Au stock solution, AgNO3, citrate-coated AgNPs, citrate-coated AuNPs, AuCl, AgNPs, AuNPs, and five commercial products to study the differences in their SERS spectral data. The observed spectra of AgNPs and AuNPs have similar peaks at ~ 390, ~ 1087, and ~ 1590 cm−1 that can be attributed to the C–S stretching vibration, C–C stretching vibration, and C–H stretching vibration, respectively. Neutron activation analysis (NAA) and electron microscopy was used to characterize and quantify AgNPs and AuNPs in the consumer products. The results demonstrate that SERS method in combination with NAA can be an effective method for detection of ENMs, and it can easily distinguish AgNPs and AuNPs from other non-nanoparticle species in the complex matrices.

The antibacterial properties of Se NPs were investigated against four foodborne pathogens (Escherichia coli O157:H7, Staphylococcus aureus, Salmonella, and Listeria monocytogenes). The cytotoxicity of Se NPs was also studied using the Caco-2 cell line. Se NPs at concentrations of 10 μg/mL or higher exhibited dose-dependent antimicrobial properties against S. aureus, but not on the other three pathogens. Se NPs also exhibited various degrees of toxicity on Caco-2 cells after 24 h of exposure. Cellular shrinkage and irregular shapes of treated bacterial cells indicated that the antimicrobial effects of Se NPs are bacteriostatic, not bactericidal. This is the first study to investigate the antimicrobial activity of Se NPs against important foodborne pathogens. The results of this study demonstrate that Se NPs can be used as an antimicrobial agent to inhibit the growth of S. aureus and can be potentially used for food safety applications.

Silver nanoparticles (Ag NPs) are one of the top five engineered nanoparticles that have been used in various products. Current methods for the measurement of Ag NPs are time consuming and expensive. Therefore, it is of critical importance to develop novel strategies to detect the presence of Ag NPs at low concentrations in different matrices. This study aimed at detecting and measuring Ag NPs in consumer products using surface-enhanced Raman spectroscopy (SERS) coupled with aminothiophenol (PATP) as an indicator molecule that binds strongly with Ag NPs. Quantification and qualification of Ag NPs were achieved using this method of acquiring SERS signals from Ag NP-PATP complexes. Four dietary supplement products and one nasal spray were selected to evaluate the performance of SERS in the detection of Ag NPs. Inductively coupled plasma optical emission spectrometry (ICP-OES) and transmission electron microscopy (TEM) were utilized to measure the physical properties of Ag NPs in the samples. The results demonstrate that distinctive Raman peaks of PATP can be used to distinguish Ag NPs from silver bulk particles and silver nitrate. SERS is able to detect Ag NPs with different sizes ranging from 20 to 100 nm, with the highest intensity for ∼30 nm Ag NPs. A partial least squares method was used to develop quantitative models for the analysis of spectral data (R = 0.94). These results indicate that the conjugation of Ag NPs with PATP can be measured by SERS. These results demonstrate that SERS is a simple and rapid method and has great potential to detect Ag NPs in various products.

With growing consumption of aquaculture products, there is increasing demand on rapid and sensitive techniques that can detect prohibited substances in the seafood products. This study aimed to develop a novel surface-enhanced Raman spectroscopy (SERS) method coupled with simplified extraction protocol and novel gold nanorod (AuNR) substrates to detect banned aquaculture substances (malachite green [MG] and crystal violet [CV]) and their mixture (1:1) in aqueous solution and fish samples. Multivariate statistical tools such as principal component analysis (PCA) and partial least squares regression (PLSR) were used in data analysis. PCA results demonstrate that SERS can distinguish MG, CV and their mixture (1:1) in aqueous solution and in fish samples. The detection limit of SERS coupled with standing AuNR substrates is 1 ppb for both MG and CV in fish samples. A good linear relationship between the actual concentration and predicted concentration of analytes based on PLSR models with R2 values from 0.87 to 0.99 were obtained, indicating satisfactory quantification results of this method. These results demonstrate that the SERS method coupled with AuNR substrates can be used for rapid and accurate detection of MG and CV in fish samples.

Engineered nanoparticles (ENPs), such as metallic or metallic oxide nanoparticles (NPs), have gained much attention in recent years. Increasing use of ENPs in various areas may lead to the release of ENPs into the environment and cause the contamination of agricultural and food products by ENPs. In this study, we selected two important ENPs (zinc oxide [ZnO] and silver [Ag] NPs) as potential food contaminants and investigated their toxicity via an in vitro model using Caco-2 cells. The physical properties of ENPs and their effects on Caco-2 cells were characterized by electron microscopy and energy dispersive X-ray spectroscopic (EDS) techniques. Results demonstrate that a significant inhibition of cell viability was observed after a 24-h of exposure of Caco-2 cells to 3-, 6-, and 12-mM ZnO NPs or 0.5-, 1.5-, and 3-mM Ag NPs. The noticeable changes of cells include the alteration in cell shape, abnormal nuclear structure, membrane blebbing, and cytoplasmic deterioration. The toxicity of ZnO NPs, but not that of Ag NPs after exposure to simulated gastric fluid, significantly decreased. Scanning transmission electron microscopy shows that ZnO and Ag NPs penetrated the membrane of Caco-2 cells. EDS results also confirm the presence of NPs in the cytoplasm of the cells. This study demonstrates that ZnO and Ag NPs have cytotoxic effects and can inhibit the growth of Caco-2 cells.

The objectives of this study were to compare the volatile compounds, the taste compounds, and the sensory attributes, and also to determine the relationship between them in four commercial brand oyster sauces. The volatile compounds were extracted and detected by headspace-solid phase microextraction and gas chromatography-mass spectrometry. The sensory evaluation was carried out by 11 trained panelists. In addition, free amino acids and minerals in four samples were quantified and selected as the taste compounds. A total of 75 volatile compounds were identified with alcohols, furans, aldehydes, and pryrasines reported as the most dominant chemical classes. Most of the samples showed the clear sensory groupings with significant differences. Glutamic was the dominant free amino acid in all samples. Sweet amino acids, including threonine, serine, glycine, and alanine, corresponded to the high intensities of sweet sensory attributes by the canonical correlation analysis. Phosphate and potassium were believed...

In recent years, novel nanomaterials have received much attention due to their great potential for applications in agriculture, food safety, and food packaging. Among them, graphene and graphene oxide (GO) are emerging as promising nanomaterials that may have a profound impact on food packaging. However, there are some concerns from consumers and the scientific community about the potential toxicity and biocompatibility of nanomaterials. In this study, we investigated the antibacterial properties of GO against human intestinal bacteria. The cytotoxicity of GO was also studied in vitro using the Caco-2 cell line derived from a colon carcinoma. Electron microscopy was used to investigate the morphology of GO and the interaction between GO flakes and Caco-2 cells. GO at different concentrations (10 to 500 μg/ml) exhibited no toxicity against the selected bacteria and a mild cytotoxic action on Caco-2 cells after 24 h of exposure. The results show that weak adsorption of medium nutrients may contribute to GO's low toxicity. This study suggests that GO is biocompatible and has a potential to be used in agriculture and food science, indicating that more studies are needed to exploit its potential applications.