A colorimetric smartphone-based sensor for on-site AA detection in tropical fruits using Fe-P/NC single-atom nanoenzyme

Ascorbic acid is one of the important vitamins to maintain human life activities and plays an irreplaceable role in regulating human redox metabolism. Fresh fruit can provide plenty of AA to maintain human metabolic balance. Thus, it is great significant to develop a rapid and convenient method for detection of AA to evaluate the freshness and nutritional quality of fruits. In this work, Fe single-atom nanoenzyme (Fe-SAN) based colorimetric sensor assisted with smartphone was designed for rapid and on-site AA detection in tropical fruits. Firstly, Fe-SAN with high oxidase-mimicking activity was synthesized by using green tea leaves as sources of carbon and nitrogen and NaH₂PO₂ as P source to obtain Fe-P/NC SAN, in which P was used to reconstruct the distribution of electronic to enhance the oxidase-mimicking activity of Fe-SAN. Besides, the as-synthesized Fe-P/NC SAN with remarkable oxidase-like activities could oxidize 3,3́,5,5́-tetramethylbenzidine (TMB) to blue colored oxidized TMB. AA could inhibit the oxidation of TMB, leading to blue fading. Based on the above principle, colorimetric sensor integrated with smartphone RGB mode was fabricated and exhibited a good linear detection range (0.5-100 μM) and low detection limit of 0.315 μM for AA detection under optimal conditions. More importantly, the developed sensor could rapidly and accurately detect AA in real sample, such as pineapple, wax apple and mango. Therefore, this research provides a new cost-effective method for the efficient and exact detection of AA in tropical fruit, which has a broad application prospect.

Comparison of energy consumption, color, ascorbic acid and carotenoid degradation in guava (Psidium guajava) pulp during conventional and ohmic heating

This study aimed to compare the effect of ohmic and conventional heat treatments on red guava pulp, evaluating the effects on pulp color, degradation kinetics of ascorbic acid and carotenoids, together with the thermal efficiency of both treatments. Samples were heated by conventional heating (water bath) and ohmic heating (platinum electrodes) using alternating voltage of 21.2 V/m and average frequency of 60 Hz at temperatures of 60, 70 and 80 °C for 110 min. In general, the ascorbic acid degradation followed a first order kinetics, for both heat treatments, the pulp color showed no significant variation (p < 0.05) according to the type and time of heating applied, whereas the carotenoid content was favored by ohmic heating, at the two lowest temperatures tested. As for the heat transfer process, the ohmic treatment showed an average thermal efficiency of 40.93%, while the conventional heating, 2.62%, proving to be a promising emerging technology for processing viscous foods with suspended particles like fruit pulps.

Application of Potentially Probiotic Fruit-Derived Lactic Acid Bacteria Loaded into Sodium Alginate Coatings to Control Anthracnose Development in Guava and Mango During Storage

This study evaluated the efficacy of potentially probiotic fruit-derived lactic acid bacteria (LAB) strains loaded into sodium alginate (SA) coatings to control the anthracnose development in guava cv. Paluma and mango cv. Palmer caused by distinct pathogenic Colletotrichum species (C. asianum, C. fructicola, C. tropicale, C. siamense, C. karstii, and C. gloeosporioides) during 15 days of room temperature storage (25 ± 0.5 °C). The effects of the formulated coatings on physicochemical parameters indicative of overall postharvest quality of guava and mango were evaluated. The eight examined LAB strains caused strong inhibition on the mycelial growth of all target Colletotrichum species in vitro. LAB strains with the highest inhibitory effects (Levilactobacillus brevis 59, Lactiplantibacillus pentosus 129, and Limosilactobacillus fermentum 263) on the target Colletotrichum species were incorporated into SA coatings. These strains had viable counts of > 6 log CFU/mL in SA coatings during 15 days of room temperature storage. Application of coatings with SA + L. brevis 59, SA + L. pentosus 129, and SA + L. fermentum 263 delayed the development and decreased the severity of anthracnose lesions in guava and mango artificially contaminated with either of the tested Colletotrichum species. These coatings impacted positively on some physicochemical parameters indicative of postharvest quality and more prolonged storability of guava and mango. The formulated SA coatings loaded with tested fruit-derived potentially probiotic LAB strains could be innovative and effective strategies to control postharvest anthracnose and extend the storability of guava and mango.

A Phosphoproteomic Analysis Pipeline for Peels of Tropical Fruits

Phosphorylation is a posttranslational reversible modification related to signaling and regulatory mechanisms. Protein phosphorylation is linked to structural changes that modulate protein activity, interaction, or localization and therefore the cell signaling pathways. The use of techniques for phosphoprotein enrichment along with mass spectrometry has become a powerful tool for the characterization of signal transduction in model organisms. However, limited efforts have focused on the establishment of protocols for the analysis of the phosphoproteome in nonmodel organisms such as tropical fruits. This chapter describes a potential pipeline for sample preparation and enrichment of phosphorylated proteins/peptides before MS analysis of peels of some species of tropical fruits.

Phenolic-rich smoothie consumption ameliorates non-alcoholic fatty liver disease in obesity mice by increasing antioxidant response

Consumption of foods rich in phenolic compounds can be beneficial for health. This study aimed to examine whether the consumption of a phenolic-rich smoothie, based on juçara, strawberry and banana, ameliorates metabolic status and liver damage of diet-induced obese mice. Forty male C57BL/6J mice were assigned into four groups (n = 10) and fed control diet with free access to water (C) or phenolic-rich smoothie (C-S), or fed high-fat diet with free access to water (HF) or phenolic-rich smoothie (HF-S) for five weeks. HF and HF-S groups had higher body weight gains than the C group, however the HF had a greater adipose index, higher plasma levels of glucose, insulin and leptin, as well as higher plasma and hepatic steatosis than C, C-S and HF-S groups. The liver oxidative stress markers were reduced in C-S and HF-S groups and the activity of catalase and glutathione peroxidase were higher compared with their counterparts. The present study suggests that regular consumption of a phenolic-rich smoothie improves the liver antioxidant status, prevents metabolic disorders and ameliorates non-alcoholic fatty liver disease caused by high-fat diet consumption.

Biomarkers of intake for tropical fruits

Consumption of fruit and vegetable is a key component of a healthy and sustainable diet. However, their accurate dietary assessment remains a challenge. Due to errors in self-reporting methods, the available dietary information is usually biased. Biomarkers of intake constitute objective tools to better reflect the usual or recent consumption of different foods, including fruits and vegetables. Partners of The Food Biomarker Alliance (FoodBall) Project have undertaken the task of reviewing the available literature on putative biomarkers of tropical fruit intake. The identified candidate biomarkers were subject to validation evaluation using eight biological and chemical criteria. This publication presents the current knowledge on intake biomarkers for 17 tropical fruits including banana, mango, and avocado as the most widely consumed ones. Candidate biomarkers were found only for banana, avocado, and watermelon. An array of banana-derived metabolites has been reported in human biofluids, among which 5-hydroxyindole-acetic acid, dopamine sulfate, methoxyeugenol glucuronide, salsolinol sulfate, 6-hydroxy-1-methyl-1,2,3,4-tetrahydro-β-carboline-sulfate, and other catecholamine metabolites. Their validation is still at an early stage, with insufficient data on dose-response relationship. Perseitol and mannoheptulose have recently been reported as candidate biomarkers for avocado intake, while the amino acid citrulline has been associated with watermelon intake. Additionally, the examination of food composition data revealed some highly specific phytochemicals, which metabolites after absorption may be further studied as putative BFI for one or several tropical fruits. To make the field move forward, untargeted metabolomics, as a data-driven explorative approach, will have to be applied in both intervention and observational studies to discover putative BFIs, while their full validation and the establishment of dose-response calibration curves will require quantification methods at a later stage.

Physicochemical composition, phytochemical analysis and biological activity of ciricote (Cordia dodecandra A. D.C.) fruit from Yucatán

The physicochemical properties, proximate composition, minerals, total polyphenols, carotenoids, phenolic compounds, antioxidant, and antibacterial activities of ciricote (Cordia dodecandra A. DC.) tropical fruit were investigated. Minerals were quantified by using micro-Energy Dispersive X-Ray Fluorescence. Lutein and β-carotene were identified in ciricote fruit by using UPLC-PDA analysis. The highest values of the total polyphenols content and antioxidant activity were presented in ethanolic crude extracts obtaining by the ultrasonic-assisted method with freeze-dried fruit. The phenolic acids profile was identified and quantified by UPLC-PDA-ESI-MS. The main phenolic acids were caffeoyl hexoside, rufescenolide, quercetin 3-O-rutinoside, and rosmarinic acid. The ciricote extracts presented antibacterial activity against Staphylococus aureus (Gram+) and Salmonella typhymurium (Gram-). In conclusion, the ciricote (Cordia dodecandra A. DC.) tropical fruits could be very useful source of biological macromolecules, micro-elements, and phytochemical compounds for the food and pharmaceutical industry.

Use of inductors in the control of Colletotrichum gloeosporioides and Rhizopus stolonifer isolated from soursop fruits: in vitro tests

Soursop (Annona muricata) is a tropical fruit that can be infected by Colletotrichum gloeosporioides and Rhizopus stolonifer. Traditional methods used for postharvest disease control include the application of fungicides, however due to their excessive use, as well as their persistence in the environment, the development of new strategies that control pathogens are required. The application of chitosan (Chi), salicylic acid (SA) and methyl jasmonate (MJ) is an environmentally-friendly alternative with antimicrobial properties and also induces defense mechanisms in plant tissues. In this study, Colletotrichum was reactivated and Rhizopus was identified using morphological features and molecular tools. In vitro, the application of 0.5 and 1.0% of Chi alone or in combination with SA and MJ decreased mycelial growth and sporulation, a complete inhibition of spore germination was obtained. Thus, the application of Chi in combination with SA and MJ could be a smart strategy to inhibit the development of pathogens that attack soursop fruit.

Analysis of phylogeny, distribution, and pathogenicity of Botryosphaeriaceae species associated with gummosis of Anacardium in Brazil, with a new species of Lasiodiplodia

Netto, M. S. B., Lima, W. G., Correia, K. C., da Silva, C. F. B., Thon, M., Martins, R. B., Miller, R. N. G., Michereff, S. J., and Câmara, M. P. S. 2016. Analysis of phylogeny, distribution, and pathogenicity of Botryosphaeriaceae species associated with gummosis of Anacardium in Brazil, with a new species of Lasiodiplodia. We identified Botryosphaeriaceae species associated with gummosis on Anacardium in Brazil. Isolates were sampled and identified on the basis morphology and phylogeny, through analysis of a partial translation elongation factor 1-α sequence, ribosomal DNA internal transcribed spacers, and β-tubulin gene sequence. Ten taxa were identified, namely, Lasiodiplodia brasiliense, L. euphorbicola, L. gonubiensis, L. iraniensis, L. jatrophicola, L. gravistriata sp. nov., L. pseudotheobromae, L. theobromae, Neofusicoccum batangarum, and Pseudofusicoccum stromaticum. Lasiodiplodia theobromae has been previously reported in cashew and is the most prevalent species observed. All the other species are reported here for the first time on this host. All species of Botryosphaeriaceae were pathogenic on detached green cashew shoots. Differences in aggressiveness were observed among the species, with N. batangarum, L. iraniensis, L. jatrophicola, and L. gravistriata characterized as the most aggressive species, whilst L. euphorbicola and L. pseudotheobromae were identified as the least aggressive.

Carbon footprint of premium quality export bananas: case study in Ecuador, the world's largest exporter

Nowadays, the new international market demands challenge the food producing countries to include the measurement of the environmental impact generated along the production process for their products. In order to comply with the environmentally responsible market requests the measurement of the greenhouse gas emissions of Ecuadorian agricultural goods has been promoted employing the carbon footprint concept. Ecuador is the largest exporter of bananas in the world. Within this context, this study is a first assessment of the carbon footprint of the Ecuadorian premium export banana (Musa AAA) using a considerable amount of field data. The system boundaries considered from agricultural production to delivery in a European destination port. The data collected over three years permitted identifying the hot spot stages. For the calculation, the CCaLC V3.0 software developed by the University of Manchester is used. The carbon footprint of the Ecuadorian export banana ranged from 0.45 to 1.04 kg CO2-equivalent/kg banana depending on the international overseas transport employed. The principal contributors to the carbon footprint are the on farm production and overseas transport stages. Mitigation and reduction strategies were suggested for the main emission sources in order to achieve sustainable banana production.