Technological properties of maize tortillas produced by microwave nixtamalization with variable alkalinity

This research was conducted to determine the quality, physicochemical, textural, compositional, nutritional, viscoamylographic and sensory properties of maize tortillas produced with a Modified tortilla-making process (MTMP) of variable alkalinity (0.125, 0.25 and 0.5% Ca(OH)2 w/w) and compared to the commercial brand MASECA ®. In general, tortillas from MTMP showed higher pH, total color difference (ΔE), tensile strength/cutting force, protein, lipids, crude fibre, lysine, tryptophan, in vitro protein digestibility and lower Hunter L value, loss of weight during cooking and moisture content than MASECA® tortillas. No significant differences were found in the sensory analysis of 22 descriptors of tortillas made from MASECA® and MTMP with Ca(OH)2 concentrations of 0.125 and 0.25% (w/w). However, panelist identified principal effects on changes in four attributes (aroma, appearance, flavor, and after taste flavor) and seven descriptors in tortillas from MTMP prepared with the maximum lime concentration (0.5% w/w). Microwave nixtamalization produce tortillas with acceptable physicochemical, textural, quality, compositional/nutritional and pasting properties.Key words: Maize, modified nixtamalization, tortillas, technological properties

Changes in cocoa properties induced by the alkalization process: A review

[EN] Alkalization, also known as "Dutching," is an optional, but very useful, step taken in the production chain of cocoa to darken its color, modify its taste, and increase natural cocoa solubility. Over the years, various attempts have been made to design new and more effective alkalization methods. Moreover, different authors have attempted to elucidate the impact of alkalization on the physicochemical, nutritional, functional, microbiological, and sensory characteristics of alkalized cocoa. The aim of this review is to provide a clear guide about not only the conditions that can be applied to alkalize cocoa, but also the reported effects of alkalization on the nutritional, functional, microbiological, and sensory characteristics of cocoa. The first part of this review describes different cocoa alkalization systems and how they can be tuned to induce specific changes in cocoa properties. The second part is a holistic analysis of the effects of the alkalization process on different cocoa features, performed by emphasizing the biochemistry behind all these transformations.European Regional Development Fund, Grant/Award Number: Project RTC-2016-5241-2; Ministerio deEconomia y Competitividad, Grant/Award Number: Project RTC-2016-5241-2Valverde-Garcia, D.; Pérez-Esteve, É.; Barat Baviera, JM. (2020). Changes in cocoa properties induced by the alkalization process: A review. Comprehensive Reviews in Food Science and Food Safety. 19(4):2200-2221. https://doi.org/10.1111/1541-4337.12581S22002221194Ilesanmi Adeyeye, E. (2016). Proximate, Mineral And Antinutrient Compositions Of Natural Cocoa Cake, Cocoa Liquor And Alkalized Cocoa Powders. Journal of Advanced Pharmaceutical Science And Technology, 1(3), 12-28. doi:10.14302/issn.2328-0182.japst-15-855Ajandouz, E. H., Tchiakpe, L. S., Ore, F. D., Benajiba, A., & Puigserver, A. (2001). Effects of pH on Caramelization and Maillard Reaction Kinetics in Fructose-Lysine Model Systems. Journal of Food Science, 66(7), 926-931. doi:10.1111/j.1365-2621.2001.tb08213.xAndres-Lacueva, C., Monagas, M., Khan, N., Izquierdo-Pulido, M., Urpi-Sarda, M., Permanyer, J., & Lamuela-Raventós, R. M. (2008). Flavanol and Flavonol Contents of Cocoa Powder Products: Influence of the Manufacturing Process. Journal of Agricultural and Food Chemistry, 56(9), 3111-3117. doi:10.1021/jf0728754Andruszkiewicz, P. J., D’Souza, R. N., Altun, I., Corno, M., & Kuhnert, N. (2019). Thermally-induced formation of taste-active 2,5-diketopiperazines from short-chain peptide precursors in cocoa. Food Research International, 121, 217-228. doi:10.1016/j.foodres.2019.03.015Aprotosoaie, A. C., Luca, S. V., & Miron, A. (2015). Flavor Chemistry of Cocoa and Cocoa Products-An Overview. Comprehensive Reviews in Food Science and Food Safety, 15(1), 73-91. doi:10.1111/1541-4337.12180Aremu, C. Y., Agiang, M. A., & Ayatse, J. O. I. (1995). Nutrient and antinutrient profiles of raw and fermented cocoa beans. Plant Foods for Human Nutrition, 48(3), 217-223. doi:10.1007/bf01088443Bandi J. P. Kubicek K. &Raboud P. B.(1984).Installation for solubilizing cocoa. US4438681A.Baigrie, B. D. (1994). Cocoa flavour. Understanding Natural Flavors, 268-282. doi:10.1007/978-1-4615-2143-3_17Bartella, L., Di Donna, L., Napoli, A., Siciliano, C., Sindona, G., & Mazzotti, F. (2019). A rapid method for the assay of methylxanthines alkaloids: Theobromine, theophylline and caffeine, in cocoa products and drugs by paper spray tandem mass spectrometry. Food Chemistry, 278, 261-266. doi:10.1016/j.foodchem.2018.11.072Bauermeister J.(1989).Process for making cacao powder by disagglomeration and cacao powder granulate by subsequent agglomeration. EP0310790A2.Beg, M. S., Ahmad, S., Jan, K., & Bashir, K. (2017). Status, supply chain and processing of cocoa - A review. Trends in Food Science & Technology, 66, 108-116. doi:10.1016/j.tifs.2017.06.007Biehl B.(1986).Cocoa fermentation and problem of acidity over‐fermentation and low cocoa flavour.Selangor Malaysia: Incorporated Society of Planters.Serra Bonvehí, J., & Ventura Coll, F. (2000). Evaluation of purine alkaloids and diketopiperazines contents in processed cocoa powder. European Food Research and Technology, 210(3), 189-195. doi:10.1007/pl00005510Borthwick, A. D., & Da Costa, N. C. (2015). 2,5-diketopiperazines in food and beverages: Taste and bioactivity. Critical Reviews in Food Science and Nutrition, 57(4), 718-742. doi:10.1080/10408398.2014.911142Chalin M. L.(1972).Method of dutching cocoa. US3868469A.Rainer Cremer, D. (2000). The reaction kinetics for the formation of Strecker aldehydes in low moisture model systems and in plant powders. Food Chemistry, 71(1), 37-43. doi:10.1016/s0308-8146(00)00122-9De Vuyst, L., & Weckx, S. (2016). The cocoa bean fermentation process: from ecosystem analysis to starter culture development. Journal of Applied Microbiology, 121(1), 5-17. doi:10.1111/jam.13045Del Rio, D., Costa, L. G., Lean, M. E. J., & Crozier, A. (2010). Polyphenols and health: What compounds are involved? Nutrition, Metabolism and Cardiovascular Diseases, 20(1), 1-6. doi:10.1016/j.numecd.2009.05.015Domínguez-Rodríguez, G., Marina, M. L., & Plaza, M. (2017). Strategies for the extraction and analysis of non-extractable polyphenols from plants. Journal of Chromatography A, 1514, 1-15. doi:10.1016/j.chroma.2017.07.066El Gharras, H. (2009). Polyphenols: food sources, properties and applications - a review. International Journal of Food Science & Technology, 44(12), 2512-2518. doi:10.1111/j.1365-2621.2009.02077.xEllis L. D.(1990).Process for making dark cocoa. US5114730A.Ellis L. D. (1992).Process for making dark cocoa. US5114730A.Lu, F., Rodriguez-Garcia, J., Van Damme, I., Westwood, N. J., Shaw, L., Robinson, J. S., … Charalampopoulos, D. (2018). Valorisation strategies for cocoa pod husk and its fractions. Current Opinion in Green and Sustainable Chemistry, 14, 80-88. doi:10.1016/j.cogsc.2018.07.007Franco, R., Oñatibia-Astibia, A., & Martínez-Pinilla, E. (2013). Health Benefits of Methylxanthines in Cacao and Chocolate. Nutrients, 5(10), 4159-4173. doi:10.3390/nu5104159Germann, D., Stark, T. D., & Hofmann, T. (2019). Formation and Characterization of Polyphenol-Derived Red Chromophores. Enhancing the Color of Processed Cocoa Powders: Part 1. Journal of Agricultural and Food Chemistry, 67(16), 4632-4642. doi:10.1021/acs.jafc.9b01049Germann, D., Stark, T. D., & Hofmann, T. (2019). Formation and Characterization of Polyphenol-Derived Red Chromophores. Enhancing the Color of Processed Cocoa Powders: Part 2. Journal of Agricultural and Food Chemistry, 67(16), 4643-4651. doi:10.1021/acs.jafc.9b01050Gobert, J., & Glomb, M. A. (2009). Degradation of Glucose: Reinvestigation of Reactive α-Dicarbonyl Compounds†. Journal of Agricultural and Food Chemistry, 57(18), 8591-8597. doi:10.1021/jf9019085Gu, L., House, S. E., Wu, X., Ou, B., & Prior, R. L. (2006). Procyanidin and Catechin Contents and Antioxidant Capacity of Cocoa and Chocolate Products. Journal of Agricultural and Food Chemistry, 54(11), 4057-4061. doi:10.1021/jf060360rGültekin-Özgüven, M., Berktaş, I., & Özçelik, B. (2016). Change in stability of procyanidins, antioxidant capacity and in-vitro bioaccessibility during processing of cocoa powder from cocoa beans. LWT - Food Science and Technology, 72, 559-565. doi:10.1016/j.lwt.2016.04.065Hagerman, A. E. (1992). Tannin—Protein Interactions. Phenolic Compounds in Food and Their Effects on Health I, 236-247. doi:10.1021/bk-1992-0506.ch019Holkar, C. R., Jadhav, A. J., & Pinjari, D. V. (2019). A critical review on the possible remediation of sediment in cocoa/coffee flavored milk. Trends in Food Science & Technology, 86, 199-208. doi:10.1016/j.tifs.2019.02.035Huang, Y., & Barringer, S. A. (2010). Alkylpyrazines and Other Volatiles in Cocoa Liquors at pH 5 to 8, by Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS). Journal of Food Science, 75(1), C121-C127. doi:10.1111/j.1750-3841.2009.01455.xHurst, W. J., Krake, S. H., Bergmeier, S. C., Payne, M. J., Miller, K. B., & Stuart, D. A. (2011). Impact of fermentation, drying, roasting and Dutch processing on flavan-3-ol stereochemistry in cacao beans and cocoa ingredients. Chemistry Central Journal, 5(1). doi:10.1186/1752-153x-5-53International Cocoa Organization(2017).Annual report 2014/2015 Retrieved fromhttps://www.icco.org/about-us/international-cocoa-agreements/cat_view/1-annual-report.html.Mazor Jolić, S., Radojčić Redovniković, I., Marković, K., Ivanec Šipušić, Đ., & Delonga, K. (2011). Changes of phenolic compounds and antioxidant capacity in cocoa beans processing. International Journal of Food Science & Technology, 46(9), 1793-1800. doi:10.1111/j.1365-2621.2011.02670.xKofink, M., Papagiannopoulos, M., & Galensa, R. (2007). (-)-Catechin in Cocoa and Chocolate: Occurence and Analysis of an Atypical Flavan-3-ol Enantiomer. Molecules, 12(7), 1274-1288. doi:10.3390/12071274Kongor, J. E., Hinneh, M., de Walle, D. V., Afoakwa, E. O., Boeckx, P., & Dewettinck, K. (2016). Factors influencing quality variation in cocoa (Theobroma cacao) bean flavour profile — A review. Food Research International, 82, 44-52. doi:10.1016/j.foodres.2016.01.012Kopp G. M. Hennen J. C. Seyller M. &Brandstetter B.(2010).Process for producing high flavour cocoa. EP2241190A1.Kruszewski, B., & Obiedziński, M. W. (2020). Impact of Raw Materials and Production Processes on Furan and Acrylamide Contents in Dark Chocolate. Journal of Agricultural and Food Chemistry, 68(8), 2562-2569. doi:10.1021/acs.jafc.0c00412Lan, X., Liu, P., Xia, S., Jia, C., Mukunzi, D., Zhang, X., … Xiao, Z. (2010). Temperature effect on the non-volatile compounds of Maillard reaction products derived from xylose–soybean peptide system: Further insights into thermal degradation and cross-linking. Food Chemistry, 120(4), 967-972. doi:10.1016/j.foodchem.2009.11.033Li, Y., Feng, Y., Zhu, S., Luo, C., Ma, J., & Zhong, F. (2012). The effect of alkalization on the bioactive and flavor related components in commercial cocoa powder. Journal of Food Composition and Analysis, 25(1), 17-23. doi:10.1016/j.jfca.2011.04.010Li, Y., Zhu, S., Feng, Y., Xu, F., Ma, J., & Zhong, F. (2013). Influence of alkalization treatment on the color quality and the total phenolic and anthocyanin contents in cocoa powder. Food Science and Biotechnology, 23(1), 59-63. doi:10.1007/s10068-014-0008-5Lima, L. J. R., Kamphuis, H. J., Nout, M. J. R., & Zwietering, M. H. (2011). Microbiota of cocoa powder with particular reference to aerobic thermoresistant spore-formers. Food Microbiology, 28(3), 573-582. doi:10.1016/j.fm.2010.11.011MALEYKI, M. J. A., & ISMAIL, A. (2010). ANTIOXIDANT PROPERTIES OF COCOA POWDER. Journal of Food Biochemistry, 34(1), 111-128. doi:10.1111/j.1745-4514.2009.00268.xMartín, M. Á., & Ramos, S. (2017). Health beneficial effects of cocoa phenolic compounds: a mini-review. Current Opinion in Food Science, 14, 20-25. doi:10.1016/j.cofs.2016.12.002Martin, M. A., Goya, L., & Ramos, S. (2013). Potential for preventive effects of cocoa and cocoa polyphenols in cancer. Food and Chemical Toxicology, 56, 336-351. doi:10.1016/j.fct.2013.02.020Méndez-Albores, A., De Jesús-Flores, F., Castañeda-Roldan, E., Arámbula-Villa, G., & Moreno-Martı́nez, E. (2004). The effect of toasting and boiling on the fate of B-aflatoxins during pinole preparation. Journal of Food Engineering, 65(4), 585-589. doi:10.1016/j.jfoodeng.2004.02.024Miller, K. B., Hurst, W. J., Payne, M. J., Stuart, D. A., Apgar, J., Sweigart, D. S., & Ou, B. (2008). Impact of Alkalization on the Antioxidant and Flavanol Content of Commercial Cocoa Powders. Journal of Agricultural and Food Chemistry, 56(18), 8527-8533. doi:10.1021/jf801670pOlam. (2017).The De Zaan cocoa manual. The Netherlands: Archer Daniels Midland Company BV.ODUNS, A. A., & LONGE, O. G. (1998). Nutritive value of hot water- or cocoa-pod ash solution-treated cocoa bean cake for broiler chicks. British Poultry Science, 39(4), 519-525. doi:10.1080/00071669888700Ofosu, I. W., Ankar-Brewoo, G. M., Lutterodt, H. E., Benefo, E. O., & Menyah, C. A. (2019). Estimated daily intake and risk of prevailing acrylamide content of alkalized roasted cocoa beans. Scientific African, 6, e00176. doi:10.1016/j.sciaf.2019.e00176Okiyama, D. C. G., Navarro, S. L. B., & Rodrigues, C. E. C. (2017). Cocoa shell and its compounds: Applications in the food industry. Trends in Food Science & Technology, 63, 103-112. doi:10.1016/j.tifs.2017.03.007Ortega, N., Romero, M.-P., Macià, A., Reguant, J., Anglès, N., Morelló, J.-R., & Motilva, M.-J. (2008). Obtention and Characterization of Phenolic Extracts from Different Cocoa Sources. Journal of Agricultural and Food Chemistry, 56(20), 9621-9627. doi:10.1021/jf8014415Pia, A. K. R., Pereira, A. P. M., Costa, R. A., Alvarenga, V. O., Freire, L., Carlin, F., & Sant’Ana, A. S. (2019). The fate of Bacillus cereus and Geobacillus stearothermophilus during alkalization of cocoa as affected by alkali concentration and use of pre-roasted nibs. Food Microbiology, 82, 99-106. doi:10.1016/j.fm.2019.01.009Quelal-Vásconez, M. A., Lerma-García, M. J., Pérez-Esteve, É., Arnau-Bonachera, A., Barat, J. M., & Talens, P. (2020). Changes in methylxanthines and flavanols during cocoa powder processing and their quantification by near-infrared spectroscopy. LWT, 117, 108598. doi:10.1016/j.lwt.2019.108598Quelal‐Vásconez, M. A., Lerma‐García, M. J., Pérez‐Esteve, É., Talens, P., & Barat, J. M. (2020). Roadmap of cocoa quality and authenticity control in the industry: A review of conventional and alternative methods. Comprehensive Reviews in Food Science and Food Safety, 19(2), 448-478. doi:10.1111/1541-4337.12522Razzaque, M. A., Saud, Z. A., Absar, N., Karim, M. R., & Hashinaga, F. (2000). Purification and Characterization of Polyphenoloxidase from Guava Infected with Fruit-rot Disease. Pakistan Journal of Biological Sciences, 3(3), 407-410. doi:10.3923/pjbs.2000.407.410Rimbach, G., Melchin, M., Moehring, J., & Wagner, A. (2009). Polyphenols from Cocoa and Vascular Health—A Critical Review. International Journal of Molecular Sciences, 10(10), 4290-4309. doi:10.3390/ijms10104290Rodríguez, P., Pérez, E., & Guzmán, R. (2009). Effect of the types and concentrations of alkali on the color of cocoa liquor. Journal of the Science of Food and Agriculture, 89(7), 1186-1194. doi:10.1002/jsfa.3573Saltini, R., Akkerman, R., & Frosch, S. (2013). Optimizing chocolate production through traceability: A review of the influence of farming practices on cocoa bean quality. Food Control, 29(1), 167-187. doi:10.1016/j.foodcont.2012.05.054Sarmadi, B., Aminuddin, F., Hamid, M., Saari, N., Abdul-Hamid, A., & Ismail, A. (2012). Hypoglycemic effects of cocoa (Theobroma cacao L.) autolysates. Food Chemistry, 134(2), 905-911. doi:10.1016/j.foodchem.2012.02.202Sarmadi, B., Ismail, A., & Hamid, M. (2011). Antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of cocoa (Theobroma cacao L.) autolysates. Food Research International, 44(1), 290-296. doi:10.1016/j.foodres.2010.10.017Scalone, G. L. L., Textoris-Taube, K., De Meulenaer, B., De Kimpe, N., Wöstemeyer, J., & Voigt, J. (2019). Cocoa-specific flavor components and their peptide precursors. Food Research International, 123, 503-515. doi:10.1016/j.foodres.2019.05.019Schroder, T., Vanhanen, L., & Savage, G. P. (2011). Oxalate content in commercially produced cocoa and dark chocolate. Journal of Food Composition and Analysis, 24(7), 916-922. doi:10.1016/j.jfca.2011.03.008Shankar, M. U., Levitan, C. A., Prescott, J., & Spence, C. (2009). The Influence of Color and Label Information on Flavor Perception. Chemosensory Perception, 2(2), 53-58. doi:10.1007/s12078-009-9046-4Singh, P., Kesharwani, R. K., & Keservani, R. K. (2017). Antioxidants and Vitamins. Sustained Energy for Enhanced Human Functions and Activity, 385-407. doi:10.1016/b978-0-12-805413-0.00024-7Tanaka M. &Terauchi M.(1999).Cocoa powder rich in polyphenols process for producing the same and modified cocoa containing the same. US6485772B1.Taş, N. G., & Gökmen, V. (2016). Effect of alkalization on the Maillard reaction products formed in cocoa during roasting. Food Research International, 89, 930-936. doi:10.1016/j.foodres.2015.12.021Terink J. &Brandon M. J.(1981).Alkalized cocoa powders and foodstuffs containing such powders. US4435436A.Todorovic, V., Milenkovic, M., Vidovic, B., Todorovic, Z., & Sobajic, S. (2017). Correlation between Antimicrobial, Antioxidant Activity, and Polyphenols of Alkalized/Nonalkalized Cocoa Powders. Journal of Food Science, 82(4), 1020-1027. doi:10.1111/1750-3841.13672Tomas-Barberán, F. A., Cienfuegos-Jovellanos, E., Marín, A., Muguerza, B., Gil-Izquierdo, A., Cerdá, B., … Espín, J. C. (2007). A New Process To Develop a Cocoa Powder with Higher Flavonoid Monomer Content and Enhanced Bioavailability in Healthy Humans. Journal of Agricultural and Food Chemistry, 55(10), 3926-3935. doi:10.1021/jf070121jTotlani, V. M., & Peterson, D. G. (2005). Reactivity of Epicatechin in Aqueous Glycine and Glucose Maillard Reaction Models:  Quenching of C2, C3, and C4 Sugar Fragments. Journal of Agricultural and Food Chemistry, 53(10), 4130-4135. doi:10.1021/jf050044xTotlani, V. M., & Peterson, D. G. (2006). Influence of Epicatechin Reactions on the Mechanisms of Maillard Product Formation in Low Moisture Model Systems. Journal of Agricultural and Food Chemistry, 55(2), 414-420. doi:10.1021/jf0617521Trout R. B.(2001).Method for making dutched cocoa. EP1278428B1.Turcotte, A.-M., Scott, P. M., & Tague, B. (2013). Analysis of cocoa products for ochratoxin A and aflatoxins. Mycotoxin Research, 29(3), 193-201. doi:10.1007/s12550-013-0167-xWang, R., Wang, T., Zheng, Q., Hu, X., Zhang, Y., & Liao, X. (2012). Effects of high hydrostatic pressure on color of spinach purée and related properties. Journal of the Science of Food and Agriculture, 92(7), 1417-1423. doi:10.1002/jsfa.4719Wiant M. J. William R. Lynch W. R. &LeFreniere R. C.(1989).Method for producing deep red and black cocoa. US5009917A.Wissgott U.(1988).Process of alkalization of cocoa in aqueous phase. US4784866A.Wollgast, J., & Anklam, E. (2000). Review on polyphenols in Theobroma cacao: changes in composition during the manufacture of chocolate and methodology for identification and quantification. Food Research International, 33(6), 423-447. doi:10.1016/s0963-9969(00)00068-5Zhang, L., Xia, Y., & Peterson, D. G. (2014). Identification of Bitter Modulating Maillard-Catechin Reaction Products. Journal of Agricultural and Food Chemistry, 62(33), 8470-8477. doi:10.1021/jf502040eZhu, Q. Y., Holt, R. R., Lazarus, S. A., Ensunsa, J. L., Hammerstone, J. F., Schmitz, H. H., & Keen, C. L. (2002). Stability of the Flavan-3-ols Epicatechin and Catechin and Related Dimeric Procyanidins Derived from Cocoa. Journal of Agricultural and Food Chemistry, 50(6), 1700-1705. doi:10.1021/jf011228

Indirect quantification of glyphosate by SERS Using an incubation process with hemin as the reporter molecule: a contribution to signal amplification mechanism

"The indirect determination of the most used herbicide worldwide, glyphosate, was achieved by the SERS technique using hemin chloride as the reporter molecule. An incubation process between hemin and glyphosate solutions was required to obtain a reproducible Raman signal on SERS substrates consisting of silicon decorated with Ag nanoparticles (Si-AgNPs). At 780 nm of excitation wavelength, SERS spectra from hemin solutions do not show extra bands in the presence of glyphosate. However, the hemin bands increase in intensity as a function of glyphosate concentration. This allows the quantification of the herbicide using as marker band the signal associated with the ring breathing mode of pyridine at 745 cm−1. The linear range was from 1 × 10−10 to 1 × 10−5 M and the limit of detection (LOD) was 9.59 × 10−12 M. This methodology was successfully applied to the quantification of the herbicide in honey. From Raman experiments with and without silver nanoparticles, it was possible to state that the hemin is the species responsible for the absorption in the absence or the presence of the herbicide via vinyl groups. Likewise, when the glyphosate concentration increases, a subtle increase occurs in the planar orientation of the vinyl group at position 2 in the porphyrin ring of hemin over the silver surface, favoring the reduction of the molecule. The total Raman signal of the hemin-glyphosate incubated solutions includes a maximized electromagnetic contribution by the use of the appropriate laser excitation, and chemical contributions related to charge transfer between silver and hemin, and from resonance properties of Raman scattering of hemin. Incubation of the reporter molecule with the analyte before the conjugation with the SERS substrate has not been explored before and could be extrapolated to other reporter-analyte systems that depend on a binding equilibrium process"

A Review on SERS-Based Detection of Human Virus Infections: Influenza and Coronavirus

The diagnosis of respiratory viruses of zoonotic origin (RVsZO) such as influenza and coronaviruses in humans is crucial, because their spread and pandemic threat are the highest. Surface–enhanced Raman spectroscopy (SERS) is an analytical technique with promising impact for the point–of–care diagnosis of viruses. It has been applied to a variety of influenza A virus subtypes, such as the H1N1 and the novel coronavirus SARS−CoV−2. In this work, a review of the strategies used for the detection of RVsZO by SERS is presented. In addition, relevant information about the SERS technique, anthropozoonosis, and RVsZO is provided for a better understanding of the theme. The direct identification is based on trapping the viruses within the interstices of plasmonic nanoparticles and recording the SERS signal from gene fragments or membrane proteins. Quantitative mono- and multiplexed assays have been achieved following an indirect format through a SERS-based sandwich immunoassay. Based on this review, the development of multiplex assays that incorporate the detection of RVsZO together with their specific biomarkers and/or secondary disease biomarkers resulting from the infection progress would be desirable. These configurations could be used as a double confirmation or to evaluate the health condition of the patient

A review on SERS-based detection of human virus infections: influenza and coronavirus

"The diagnosis of respiratory viruses of zoonotic origin (RVsZO) such as influenza and coronaviruses in humans is crucial, because their spread and pandemic threat are the highest. Surface–enhanced Raman spectroscopy (SERS) is an analytical technique with promising impact for the point–of–care diagnosis of viruses. It has been applied to a variety of influenza A virus subtypes, such as the H1N1 and the novel coronavirus SARS−CoV−2. In this work, a review of the strategies used for the detection of RVsZO by SERS is presented. In addition, relevant information about the SERS technique, anthropozoonosis, and RVsZO is provided for a better understanding of the theme. The direct identification is based on trapping the viruses within the interstices of plasmonic nanoparticles and recording the SERS signal from gene fragments or membrane proteins. Quantitative mono- and multiplexed assays have been achieved following an indirect format through a SERS-based sandwich immunoassay. Based on this review, the development of multiplex assays that incorporate the detection of RVsZO together with their specific biomarkers and/or secondary disease biomarkers resulting from the infection progress would be desirable. These configurations could be used as a double confirmation or to evaluate the health condition of the patient"

Electrochemical biosensor for sensitive quantification of glyphosate in maize kernels

"A graphite-epoxy electrode (GE) modified with multiwalled carbon nanotubes (MWCNTs) and horseradish peroxidase (GE/MWCNTs-HRP) was used to build a glyphosate biosensor whose performance in aqueous solutions depends on the enzyme activity. For the biosensor preparation, MWCNTs were deposited onto the GE surface by electrophoresis using an oxidative treatment (H2SO4/HNO3) in presence of cetyl tributylammonium bromide (CTAB) as a cationic surfactant. The surfactant was further removed from the MWCNTs surface by dipping the electrode in an EtOH/HCl solution. The physical immobilization of HRP and therefore the glyphosate sensing capabilities was tested at pH 4 where the herbicide exhibits one only species. Circular dichroism studies suggested that the secondary structure of HRP changes as a result of its interaction with glyphosate and that this change is intensified by the combination of glyphosate and H2O2, which may explain the decrease of the enzyme catalytic activity with the increase of glyphosate concentration. The glyphosate quantification in doped-maize kernels was highly reproducible and exhibits detection and quantification limits of 1.32 pM and 1.63 pM respectively. The biosensor is also characterized by a high recovery (100 %) and precision (coefficient of variation <1 %) and can be employed in presence of interfering substances such as chlorpyrifos (an organophosphate pesticide) and starch"

Green Synthesis of Silver Nanoparticles for Preparation of Gelatin Films with Antimicrobial Activity

Silver nanoparticles were successfully synthesized using Thuja orientalis aqueous extract and AgNO3 as a precursor. UV&ndash;Vis showed a distinct absorption peak at 424 nm attributed to silver nanoparticles due to their surface plasmon resonance. Atomic absorption analysis reflected an increase in the concentration of nanoparticles in relation to the progress of the synthesis, obtaining a peak concentration value of 15.7 mg/L at 50 min. The FTIR spectra revealed the characteristic functional groups of phytomolecules involved in the silver&ndash;ion binding process, such as R&ndash;O&ndash;H (3335 cm&minus;1) O=C&ndash;OH (2314 cm&minus;1) and C&mdash;C=C (1450 cm&minus;1). At 50 min, zeta potential showed the stability of the nanoparticles with the value of &minus;21.73 mV. TEM micrographs revealed the formation of spherical nanoparticles with an average size of about 85.77 nm. Furthermore, films incorporated with nanoparticles exhibited a Tg from 66.42 &deg;C to 73.71 &deg;C and Tm at 103.31 &deg;C. Films from the G22 formulation presented excellent antibacterial properties inhibiting the growth of Staphylococcus aureus. Thuja orientalis aqueous extract could be a low-cost, eco-friendly, and efficient reducing and capping agent for the synthesis of nanometric-sized Ag particles. Gelatin films with nanoparticles are expected to have high potential as an active food packaging system

Evaluation of a Solid Dispersion of Curcumin With Polyvinylpyrrolidone and Boric Acid Against Salmonella Enteritidis Infection and Intestinal Permeability in Broiler Chickens: A Pilot Study

In the present study, in vitro assays were conducted to evaluate the solubility of curcumin (CUR) alone or with polyvinylpyrrolidone (PVP) at different pH, as well as its permeability in Caco-2 cells. Results confirmed that the solid dispersion of CUR with PVP (CUR/PVP) at a 1:9 ratio, significantly increased (P &lt; 0.05) solubility and permeability compared to CUR alone. Then, the antimicrobial activity of CUR/PVP, boric acid (BA), and a combination of 0.5% CUR/PVP and 0.5% BA (CUR/PVP-BA) against Salmonella Enteritidis (SE) was determined using an in vitro digestion model that simulates crop, proventriculus, and intestine. The results revealed that in the proventriculus and intestinal compartments significant reductions of SE were observed in all the experimental treatments, but 1% BA eliminated SE in the intestinal compartment and CUR/PVP-BA showed a synergistic effect on antimicrobial activity against SE. To complement these findings, two independent in vivo trials were conducted to determine the effect of 0.1% CUR/PVP; 0.1% BA; or the combination of 0.05% CUR/PVP (1:9 ratio) and 0.05% BA (CUR/PVP-BA) on the antimicrobial activity against SE, intestinal permeability and inflammatory responses in broiler chickens. BA at 0.1% had no significant in vivo effects against SE. However, the combination of 0.05% BA and 0.05% CUR/PVP and 0.05% BA was sufficient to reduce crop and intestinal SE colonization in broiler chickens in two independent trials, confirming the synergic effect between them. A similar antimicrobial impact against SE intestinal colonization was observed in chickens treated with 0.1% CUR/PVP at a 1:9 ratio, which could be due to the increase in solubility of CUR by PVP. Furthermore, 0.1% CUR/PVP reduced the intestinal permeability of FITC-d and total intestinal IgA, as well as increase the activity of SOD when compared to control, while, CUR/PVP-BA only decreased SOD activity. Further studies to confirm and expand the in vivo results obtained in this pilot study, adding intestinal microbial commensal groups and more inflammatory biomarkers to get a complete description of the effects of BA and CUR deserves further investigation

Evaluation of the Dietary Supplementation of a Formulation Containing Ascorbic Acid and a Solid Dispersion of Curcumin with Boric Acid against <i>Salmonella</i> Enteritidis and Necrotic Enteritis in Broiler Chickens

Two experiments were conducted to evaluate the effect of the prophylactic or therapeutic administration of a 0.1% mixture containing ascorbic acid and a solid dispersion of curcumin with polyvinylpyrrolidone and boric acid (AA-CUR/PVP-BA) against Salmonella Enteritidis (S. Enteritidis) in broiler chickens. A third experiment was conducted to evaluate the impact of the dietary administration of 0.1% AA-CUR/PVP-BA in a necrotic enteritis (NE) model in broiler chickens. The prophylactic administration of 0.1% AA-CUR/PVP-BA significantly decreased S. Enteritidis colonization in cecal tonsils (CT) when compared to the positive control group (PC, p &lt; 0.05). The therapeutic administration of 0.1% AA-CUR/PVP-BA significantly reduced the concentration of S. Enteritidis by 2.05 and 2.71 log in crop and CT, respectively, when compared with the PC on day 10 post-S. Enteritidis challenge. Furthermore, the serum FITC-d concentration and total intestinal IgA levels were also significantly lower in chickens that received 0.1% AA-CUR/PVP-BA. Contrary, the PC group showed significantly higher total intestinal IgA levels compared to the negative control or AA-CUR/PVP-BA groups in the NE model. However, 0.1% AA-CUR/PVP-BA showed a better effect in reducing the concentration of S. Enteritidis when compared to the NE model. Further studies with higher concentration of AA-CUR/PVP-BA into the feed to extend these preliminary results are currently being evaluated