Cassava starch esterification with formic acid for fabrication of electrospun fibers.

Formic acid is utilized to induce esterification and chemical gelatinization in starch, particularly in the fabrication of electrospun fibers for nanomaterial production. This study investigated the impact of different concentrations (15, 20, 25, and 30 %) of cassava starch and formic acid as a solvent on the characteristics of the resultant polymeric solutions and electrospun fibers. Morphology, size distribution, thermogravimetric properties, diffraction patterns, and relative crystallinity were evaluated for the electrospun fibers. The amylose content of starch varied from 16.5 to 23.7 %, decreasing with esterification, achieving a degree of substitution of approximately 0.93. The solution-rheology exhibited elastic behavior, with viscosity increasing as starch concentration increased, hindering the fabrication of fibers at 25 and 30 % starch. Successful electrospun fibers were formed using 15 % and 20 % starch, displaying homogeneous morphologies with mean diameters of 165 nm and 301 nm, respectively. Esterification influenced thermogravimetric properties, leading to fibers with reduced degradation temperatures and mass loss compared to native starches. The electrospun fibers presented an amorphous structure, indicating a drastic reduction in relative crystallinity from 35.2 % in native starch to 8.5 % for esterified starches. This study highlights the intricate relationship between starch concentration, esterification, and solution viscosity, affecting the electrospinnability and properties of starch-polymeric solutions.

Antimicrobial activity of geranium (Pelargonium graveolens) essential oil and its encapsulation in carioca bean starch ultrafine fibers by electrospinning.

Geranium (Pelargonium graveolens) is known for being an aromatic plant rich in bioactive compounds with antibacterial properties. In this study, geranium essential oil (GEO) was extracted and encapsulated in ultrafine bean starch fibers produced by electrospinning as an antibacterial agent. GEO revealed a composition rich in volatile compounds, including citronellol, cis-geraniol, ß-linalool, citronellyl formate, and linalool formate. In its free form, GEO exhibited high antibacterial activity against pathogenic bacteria strains (L. monocytogenes, S. aureus, and E. coli). The bean starch fibers, produced with and without the addition of GEO, were uniform and continuous, with an average diameter ranging from 249 to 373 nm. Confocal analysis indicated a uniform distribution of GEO in the fibers, with a loading capacity of 54.0 %, 42.9 %, and 36.5 % for 20 %, 30 %, and 40 % GEO concentrations, respectively. Remarkably, fibers containing 40 % GEO showed a significant reduction in tested bacteria (L. monocytogenes, S. aureus, and E. coli), suggesting promising applications in preventing losses and extending the shelf life of food through active packaging.

Electrospun nanofibers based on zein and red onion bulb extract (Allium cepa, L.): Volatile compounds, hydrophilicity, and antioxidant activity.

Onion is rich in bioactive and volatile compounds with antioxidant activity. However, the pungent odor of volatile compounds (VOCs) released restricts its use. The encapsulation of red onion extract by electrospinning is an alternative to mask this odor and protect its bioactive compounds. The main objective of this study was to encapsulate red onion bulb extract (ROE) in different concentrations into zein nanofibers by electrospinning and evaluate their thermal, antioxidant, and hydrophilicity properties. The major VOC in ROE was 3(2H)-furanone, 2-hexyl-5-methyl. Incorporating ROE into the polymeric solutions increased electrical conductivity and decreased apparent viscosity, rendering nanofibers with a lower average diameter. The loading capacity of ROE on fibers was high, reaching 91.5% (10% ROE). The morphology of the nanofibers was random and continuous; however, it showed beads at the highest ROE concentration (40%). The addition of ROE to the nanofibers increased their hydrophilicity. The nanofibers' antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl, nitric oxide, and hydroxyl radicals ranged from 32.5% to 57.3%. The electrospun nanofibers have the potential to protect and mask VOCs. In addition, they offer a sustainable alternative to the synthetic antioxidants commonly employed in the food and packaging industry due to their antioxidant activities.

Natural fermentation of potato (Solanum tuberosum L.) starch: Effect of cultivar, amylose content, and drying method on expansion, chemical and morphological properties.

Natural fermentation with sun-drying is a modification that promotes the expansion capacity of starch, and its effects on potato starch have not been reported so far. The aim of this study was to evaluate the effects of the amylose content of potato (Solanum tuberosum L.) starches and natural fermentation followed by oven or sun drying on its properties. Cassava starch was also used a control. Native and fermented starches were evaluated based on their chemical composition, amylose, carboxyl and carbonyl content as well as their thermal, pasty, and morphological properties. The fermentation water was evaluated by pH and titratable acidity to control the process. Puffed balls were prepared to evaluate expandability, mass loss, porosity and texture. The fermentation intensity was greater for potato and cassava starch with low-amylose content than for potato starch with higher amylose content. In addition, the acidity of the fermentation water increased faster with cassava starch than with potato starches. The fermented potato starches with the highest amylose content had low acidity and low expansion capacity compared to the fermented potato and cassava starches with low-amylose content. Fermentation and sun-drying of low-amylose potato and cassava starches increased the expansion and reduced the hardness of the puffed balls.

Starch extraction from avocado by-product and its use for encapsulation of ginger essential oil by electrospinning.

Starches from alternative sources, such as avocado seed, have potential for application in the encapsulation of essential oils. This study aimed to extract starch from avocado seeds and its use as wall material to encapsulate ginger essential oil (GEO), at different concentrations. The fibers were produced by electrospinning and evaluated by morphology, size, infrared spectra, thermogravimetric properties, contact angle, loading capacity, and antibacterial activity. The major compounds in GEO were α-zingiberene, ß-sesquiphellandrene, α-farnesene, and α-curcumene. The starch-GEO fibers presented a higher diameter (∼553 nm) than those without GEO (345 nm). Encapsulation of GEO in starch fibers increased their thermal degradation temperatures from 165.8 °C (free GEO) to 257.6 °C (40 % GEO fibers). The starch-GEO fibers presented characteristic bands of their constituents by infrared spectra. Loading capacity ranged from 44 to 54 %. The fibers showed hydrophilic character, with a contact angle of <90°. Free GEO and the fibers with 50 % of GEO displayed antibacterial activity against Escherichia coli, proving the bioactivity of the starch-GEO fibers and its possible applicability for food packaging. Avocado seed starch showed to be a great wall material for GEO encapsulation.

Essential oil encapsulation by electrospinning and electrospraying using food proteins: A review.

Proteins are excellent polymeric materials for encapsulating essential oils (EOs) by electrospinning and electrospraying to protect these compounds and form nanomaterials with active properties. Proteins can encapsulate bioactive molecules by several mechanisms, including surface activity, absorption and stabilization mechanisms, amphiphilic nature, film-forming capacity, foaming, emulsification, and gelation, due to interactions among their functional groups. However, proteins have some limitations in encapsulating EOs by the electrohydrodynamic process. Their properties can be improved by using auxiliary polymers, increasing their charges by adding ionic salts or polyelectrolytes, denaturing their structure by heat, and exposure to specific pH conditions and ionic strength. This review addresses the main proteins used in electrospinning/electrospraying techniques, production methods, their interactions with EOs, bioactive properties, and applications in food matrices. Multivariate analysis associated with bibliometrics of metadata extracted from studies in Web of Science using the keywords electrospinning and essential oil (EO) were used as the search strategy.

Curcumin encapsulation in capsules and fibers of potato starch by electrospraying and electrospinning: Thermal resistance and antioxidant activity.

The aim of this work was to encapsulate curcumin at different concentrations in capsules and fibers of native potato starch by electrospraying and electrospinning. The best conditions for the production of capsules and fibers were obtained by varying the polymer concentration and resting time of the polymer solution. The best conditions were used for the encapsulation of curcumin. The curcumin-loaded capsules and fibers had an average diameter of 1373 nm to 1787 nm and 108 nm to 142 nm, respectively, and had a high curcumin loading capacity with values ranging from 79.01 % to 97.09 %. Curcumin encapsulated in starch capsules and fibers showed higher thermal stability at 180 °C for 2 h compared to unencapsulated curcumin. The antioxidant activity of starch fibers containing 1 % of curcumin had the greatest ability to inhibit the ABTS radical (45 % inhibition). These materials are promising for use in food or active packaging.

Biofortified sweet potatoes as a tool to combat vitamin A deficiency: Effect of food processing in carotenoid content

ABSTRACT The supply of food products that present adequate nutritional quality is extremely important for maintaining the health of the population. Thus, different techniques have been used to obtain biofortified foods, with the aim of combating malnutrition caused by the absence of essential micronutrients, especially in the poorest populations. This review presents an overview of biofortification, with an emphasis on orange-flesh sweet potatoes (OFSP), and points out the effects of food processing on nutritional compounds. The identification of cultivars and biofortification actions to obtain biofortified OFSP by conventional breeding are presented as affordable strategies to supply β-carotene to alleviate vitamin A deficiency, without having ethical dilemmas related to transgenics. Studies using OFSP have shown promising results in obtaining foods with high levels of carotenoids. However, biofortified species must be validated for crop production viability, target micronutrient bioavailability and bioaccessibility, as well as the effect of processing on nutrients, so that the benefits to human health are effectively achieved.

RESUMEN El suministro de alimentos que presenten una adecuada calidad nutricional es de suma importancia para el mantenimiento de la salud de la población. Así, se han utilizado diferentes técnicas para la obtención de alimentos biofortificados, con el objetivo de combatir la desnutrición provocada por la ausencia de micronutrientes esenciales, especialmente en las poblaciones más pobres. Esta revisión presenta una descripción general de la biofortificación, con énfasis en los camotes de pulpa anaranjada (BDPA), y señala los efectos del procesamiento de alimentos sobre los compuestos nutricionales. La identificación de cultivares y acciones de biofortificación para obtener BDPA biofortificado por mejoramiento convencional se presentan como estrategias accesibles para aportar β-caroteno para aliviar la deficiencia de vitamina A, sin presentar dilemas éticos relacionados con los transgénicos. Los estudios que utilizan BDPA han mostrado resultados prometedores en la obtención de alimentos con altos niveles de carotenoides. Sin embargo, las especies biofortificadas deben validarse no solo por la viabilidad de la producción vegetal, sino también por la biodisponibilidad y bioaccesibilidad del micronutriente objetivo, así como el efecto del procesamiento sobre los nutrientes, de modo que los beneficios para la salud humana se logren de manera efectiva.

Elaboration of food products with biofortified sweet potatoes: Characterization and sensory acceptability

ABSTRACT Beauregard sweet potato is an orange color crop rich in β-carotene, a precursor of vitamin A. β-carotene improve immunity and decrease of incidence of degenerative diseases. The objective of this work was to introduce sweet potato in the diet through of some food products, such as bread, cake and sweets. The effect of processing on the chemical composition, as well as the quantification of phenols and total carotenoids, antioxidant activity, and sensory acceptability were evaluated. Cakes and coconut sweets presented higher levels of carotenoids. Higher phenolic and antioxidant activity were verified in cocoa sweets. All foods had good acceptability: 86% for bread, 83.3% for cake and 84,4%, and 86% for coconut and cocoa sweets, respectively. Servings of 95g of roasted sweet potato, 330g of bread, 182g of cake, 187g of coconut sweet and 391g end of cocoa sweet, would provide the recommended daily intake of vitamin A for children 10 years and older. It was concluded that the elaboration of foods containing sweet potato is a viable alternative to inserting biofortified foods into the human diet.

RESUMEN Los camote Beauregard son genotipos de color naranja, ricos en β-caroteno, precursores de la vitamina A. El β-caroteno ayuda a mejorar la inmunidad y reducir el riesgo de enfermedades degenerativas. El objetivo del trabajo fue introducir el camote en la dieta a través del pan, pasteles y dulces tipo postre. Se evaluó el efecto del procesamiento sobre la composición química, así como la cuantificación de fenoles y carotenoides totales, actividad antioxidante y aceptabilidad sensorial. Las tortas y caramelos de coco mostraron mayores niveles de carotenoides y cacao, mayor actividad fenólica y antioxidante. Se confirmó una buena aceptabilidad, en la cual el pan presentó 86%, el torta 83,3%, y los dulces tipo postre de coco y de cacao 84,4% y 86% respectivamente. Las porciones de 95 g de batatas al horno, 330 g de pan, 182 g de torta, 187 g y 391 g de dulce de coco y dulce de cacao respectivamente, proporcionarían la ingesta diaria recomendada de vitamina A para niños de 10 años en adelante. Se concluyó que la preparación de alimentos que contienen batatas es una alternativa viable a la inclusión de alimentos biofortificados en la dieta humana.