A Polydiacetylene‐Based Colorimetric Sensor as an Active Use‐By Date for Plant‐Based Milk Alternatives.
Existing date marking tools, such as use-by and sell-by dates, fail to inform decision-making throughout food distribution because they do not adapt to storage conditions such as temperature. Polymer-based sensors can be incorporated into food packaging to provide an indication of food quality in real time, which can greatly reduce waste. This work identifies free fatty acid (FFA) as a marker for the quality of plant-based milk and demonstrates the first detection tool for the freshness of almond milk using phospholipid-doped polydiacetylene (PDA) vesicles. The sensor discriminates between triglycerides and FFA by a visible color change and can therefore be used to track fat metabolism during food spoilage. The interaction between FFA and PDA is investigated by electron microscopy and dynamic-light-scattering studies. PDA vesicles are then fabricated in agarose and used to discriminate between fresh and spoiled almond milk. Upon exposure of the PDA/agarose sensor to spoiled almond milk, a visible blue-to-red color change is induced in the film, which is correlated with FFA concentration in the samples. Incorporation of this technology into food packaging can be used to indicate food quality in real time, surpassing the efficacy of current date marking tools to reduce food waste.
Chemical Markers to Distinguish the Homo-and Heterozygous Bitter Genotype in Sweet Almond Kernels.
Bitterness in almonds is controlled by a single gene (Sk dominant for sweet kernel, sk recessive for bitter kernel) and the proportions of the offspring genotypes (SkSk, Sksk, sksk) depend on the progenitors' genotype. Currently, the latter is deduced after crossing by recording the phenotype of their descendants through kernel tasting. Chemical markers to early identify parental genotypes related to bitter traits can significantly enhance the efficiency of almond breeding programs. On this basis, volatile metabolites related to almond bitterness were investigated by Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry coupled to univariate and multivariate statistics on 244 homo- and heterozygous samples from 42 different cultivars. This study evidenced the association between sweet almonds' genotype and some volatile metabolites, in particular benzaldehyde, and provided for the first time chemical markers to discriminate between homo- and heterozygous sweet almond genotypes. Furthermore, a multivariate approach based on independent variables was developed to increase the reliability of almond classification. The Partial Least Square-Discriminant Analysis classification model built with selected volatile metabolites that showed discrimination capacity allowed a 98.0% correct classification. The metabolites identified, in particular benzaldehyde, become suitable markers for the early genotype identification in almonds, while a DNA molecular marker is not yet available.
Phytoprostanes and phytofurans–oxidative stress and bioactive compounds–in almonds are affected by deficit irrigation in almond trees.
Almonds have gained consumers' attention due to their health benefits (they are rich in bioactive compounds) and sensory properties. Nevertheless, information about phytoprostanes (PhytoPs) and phytofurans (PhytoFs) (new plant markers of oxidative stress and compounds with biological properties for human health) in almonds under deficit irrigation is scarce or does not exist. These compounds are plant oxylipins synthesized by the oxidation of α-linolenic acid (ALA). Besides, they are biomarkers of plant oxidative degradation and biologically active molecules involved in several plant defense mechanisms. hydroSOStainable or hydroSOS mean plant foods made from from plants under controlled water stress. Almonds are a good source of polyunsaturated fatty (PUFAs) acids, including a high content of ALA. This paper aimed to describe the influence of diverse irrigation treatments on in vitro anti-oxidant activity (AAc) and total phenolic content (TPC), as well as on the level of ALA, PhytoP, and PhytoF in "Vairo" almonds. The AAc and TPC were not affected by the irrigation strategy, while the in vivo oxidative stress makers, PhytoPs and PhytoFs, exhibited significant differences in response to water shortage. The total PhytoP and PhytoF contents ranged from 4551 to 8151 ng/100 g dry weight (dw) and from 33 to 56 ng/100 g dw, respectively. The PhytoP and PhytoF profiles identified in almonds showed significant differences among treatments. Individual PhytoPs and PhytoFs were present above the limit of detection only in almonds obtained from trees maintained under deficit irrigation (DI) conditions (regulated deficit irrigation, RDI, and sustained deficit irrigation, SDI) but not in control almonds obtained from fully irrigated trees. Therefore, these results confirm PhytoPs and PhytoFs as valuable biomarkers to detect whether an almond-based product is hydroSOStainable. As a final conclusion, it can be stated that almond quality and functionality can be improved and water irrigation consumption can be reduced if controlled DI strategies are applied in almond orchards.
A novel ratiometric near-infrared fluorescent probe for monitoring cyanide in food samples.
Cyanide is a highly toxic anion. Nonetheless, many food plants could produce endogenous cyanide, which causes great danger to human health. Thus, monitoring cyanide in food samples is critically significant. Herein, we rationally developed the first ratiometric near-infrared fluorescent probe for sensing cyanide in food samples. The probe displayed noticeable fluorescence in near-infrared region. Moreover, upon treatment with cyanide, the probe exhibited highly selective and sensitive ratiometric fluorescence response, with limit of detection determined to be 0.075 μM and limit of quantification determined to be 0.25 μM. The ratios of fluorescent intensities at 519 and 688 nm (I519/I688) was linear with added cyanide concentrations from 0 to 80 μM. The relative standard deviations for repeatability and reproducibility varied from 0.55 to 8.94 and from 1.17 to 9.46, respectively. Significantly, probe Hy has been successfully applied for monitoring cyanide in various food samples, such as almonds, sprouting potatoes, and bamboo shoots.
Effect of roasting conditions on the formation and kinetics of furan in various nuts.
In this study, the effect of roasting on the formation of furan in nuts was investigated. Nut samples were roasted at 150-200 °C for 5-25 min. As the roasting temperature and roasting time increased, the levels of furan in the nuts increased up to 348 ng/g. The concentration of furan was 2.76-224, 0.71-69.0, 1.46-348, 2.68-87.0, and 3.70-94.4 ng/g in almonds, peanuts, cashew nuts, hazelnuts, and sacha inchi, respectively. In kinetics analysis, the chemical reaction responsible for the production of furan in nuts followed the zero-order kinetic model, with reaction constants of 3.26 × 10-9 to 16.5 × 10-9mol/L.h at 200 °C. The apparent activation energy (Ea) was 125.0, 93.6, 86.5, 62.0, and 70.1 kJ/mol for almonds, peanuts, cashew nuts, hazelnuts, and sacha inchi, respectively. These results can be used to predict or to calculate furan formation in roasted nuts.
Genetic Structure of Wild Germplasm of Macadamia: Species Assignment, Diversity and Phylogeographic Relationships.
Macadamia is an Australian native rainforest tree that has been domesticated and traded internationally for its premium nuts. Common cultivars rely upon a limited gene pool that has exploited only two of the four species. Introducing a more diverse germplasm will broaden the genetic base for future crop improvement and better adaptation for changing environments. This study investigated the genetic structure of 302 accessions of wild germplasm using 2872 SNP and 8415 silicoDArT markers. Structure analysis and principal coordinate analysis (PCoA) assigned the 302 accessions into four distinct groups: (i) Macadamia integrifolia, (ii) M. tetraphylla, and (iii) M. jansenii and M. ternifolia, and (iv) admixtures or hybrids. Assignment of the four species matched well with previous characterisations, except for one M. integrifolia and four M. tetraphylla accessions. Using SNP markers, 94 previously unidentified accessions were assigned into the four distinct groups. Finally, 287 accessions were identified as pure examples of one of the four species and 15 as hybrids of M. integrifolia and M. tetraphylla. The admixed accessions showed the highest genetic diversity followed by M. integrifolia, while M. ternifolia and M. jansenii accessions were the least diverse. Mantel test analysis showed a significant correlation between genetic and geographic distance for M. integrifolia (r = 0.51, p = 0.05) and a positive but not significant correlation for M. tetraphylla (r = 0.45, p = 0.06). This study provides a population genetics overview of macadamia germplasm as a background for a conservation strategy and provides directions for future macadamia breeding.
Advances in cultivar choice, hazelnut orchard management and nuts storage for enhancing product quality and safety: an overview.
European hazelnut (Corylus avellana L.) is the major species of interest for nutritional uses within the Betulaceae family and its nuts are widely used throughout the world in the chocolate, confectionery and bakery industries. Recently his cultivation has been expanded in traditional producer countries as well as established in new places in the Southern Hemisphere, including Chile, South Africa and Australia. Introducing hazelnut in new environments could reduce its productivity, lead the trees to eco-physiological disorders and exposes the crop to high pressure of common and new pests and diseases. Thus, new approaches in cultivar choice guidance, in the sustainable orchard management and even in nuts storage and kernel quality evaluation are highly required for improving the hazelnut producing and processing chain. The main objective of this study was to systematize the published information regarding the recent findings of the cultural operations that directly influence the nut and kernel quality, support the varietal choice for new plantations and list the recent advances in nut storage and in its quality and safety evaluation.
Effects of Cashew Nut (Anacardium occidentale L.) Seed Flour in Moderately Malnourished Children: Randomized Clinical Trial.
The monitoring and combined use of dietary supplements to restore adequate growth are paramount and highly recommended in child malnutrition, an important public health problem. The objective of this study was to analyze the effects of cashew nut seed flour in children with moderate malnutrition, treated at primary healthcare services. This is a randomized clinical trial conducted from April to October 2017 in the city of Imperatriz, Brazil. The sample comprised 30 children born at term, aged between 2 and 5 years, and newly diagnosed with malnutrition (60 days or less), randomized into experimental and control groups. The intervention consisted of daily intake of cashew nut seed flour. There was intragroup statistically significant difference in the glucose levels of children who were assigned to the control group (p=0.02) and in the glycated hemoglobin in the experimental group (p < 0.01). Intergroup analysis of glycated hemoglobin levels showed statistically significant differences in favor of the experimental group (p=0.01). HDL and LDL had, respectively, increased and decreased in the experimental group. The use of cashew nut seed flour in a 24-week period had positive effects on glycated hemoglobin, HDL, and LDL parameters in moderately malnourished children.
Food allergens in skincare products marketed for children.
Background: The application of preparations containing food allergens can cause percutaneous sensitisation and provocation. The prevalence of food allergens in children's cosmetics is unknown. Objectives: To analyse the prevalence of food allergens in skincare products marketed for children and its association with marketing claims and product price. Methods: We reviewed 276 skincare product ingredient labels for the presence of milk, eggs, wheat, soy, oats, tree nuts, peanuts and sesame. Results: More than one third (108; 39.1%) of the products listed at least one allergen. A total of 156 allergens were recorded, of which 65 (41.7%) were almonds, 35 (22.4%) wheat, 24 (15.4%) soy, 16 (10.3%) oats, 13 (8.3%) sesame, 2 (1.3%) milk and 1 (0.6%) peanuts. Products that claimed to be natural or ecological were more likely to contain food allergens than those not labelled so (P < .001). The prices were higher for products containing food allergens compared to allergen-free products (P = .028). Conclusions: Food allergens are prevalent in children's cosmetics, especially those that claim to be natural or ecological. The most incorporated food allergens are almonds, wheat and soy. Products containing food allergens cost more than allergen-free ones.
Oxidative Stability of Protease Treated Peanut with Reduced Allergenicity.
Oxidative stability and allergenicity are two major concerns of peanuts. This study evaluated the impact of protease treatment of peanuts on its oxidative stability during storage. The raw and dry-roasted peanut kernels were hydrolyzed with Alcalase solution at pH 7.5 for 3 h. The contents of Ara h 1, Ara h 2, and Ara h 6 in peanuts were determined before and after enzyme treatment by a sandwich ELISA. After drying, the samples were packed in eight amber glass jars and stored at 37 °C for 1-8 weeks. Controls are untreated raw and dry-roasted peanuts packed and stored in the same way as their treated counterparts. Samples were taken biweekly to determine peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) as indicators of oxidation (n = 3), and to determine antioxidant activity. Alcalase treatment reduced intact major allergens Ara h 1, Ara h 2, and Ara h 6 by 100%, 99.8%, and 85%, respectively. The PVs of Alcalase-treated raw and roasted peanuts was lower than those of untreated (p < 0.05) over the 8-week storage. The TBARS of Alcalase-treated raw peanuts were slightly higher than that of untreated (p < 0.05), but the TBARS of Alcalase-treated dry-roasted peanuts were slightly but significantly lower than that of untreated (p < 0.05). The protease treatment increased the antioxidant activities including reducing power, DPPH free radical scavenging capacity, and metal chelating capacity of peanuts.