M.L. Zambrano-Zaragoza

The release kinetics of β-carotene nanocapsules/xanthan gum coating and quality changes in fresh-cut melon (cantaloupe)

The main aim of this work was to evaluate the effect of the β-carotene release rate from nanocapsules incorporated into a xanthan gumcoating on the physical and physicochemical properties of fresh-cut melon (var. cantaloupe). Several coatings were studied: xanthan gum alone (XG), xanthan gum combined with nanocapsules (Ncs/XG), xanthan gum combined with nanospheres (Nsp/XG), nanocapsules (Ncs), and nanospheres (Nsp), all of which were compared to untreated fresh-cut melon in order to determine their preservation efficiency. The β-carotene release profiles from the Ncs and Ncs/XG treatments corresponded better to a Higuchi-type behavior (t1/2) for matrix systems (R2>0.95). Also observed was a good correlation between the release of β-carotene by the Ncs/XG treatment and the minor changes observed in the whiteness index (≤10%) and firmness (≤2%). These results lead to the conclusion that incorporating β-carotene nanocapsules into a polysaccharide matrix improves the properties of the coatings, thereby increasing storage time to 21days at 4°C.

Nanosystems in Edible Coatings: A Novel Strategy for Food Preservation

Currently, nanotechnology represents an important tool and an efficient option for extending the shelf life of foods. Reducing particle size to nanometric scale gives materials distinct and improved properties compared to larger systems. For food applications, this technology allows the incorporation of hydrophilic and lipophilic substances with antimicrobial and antioxidant properties that can be released during storage periods to increase the shelf life of diverse products, including whole and fresh-cut fruits and vegetables, nuts, seeds, and cheese, among others. Edible coatings are usually prepared with natural polymers that are non-toxic, economical, and readily available. Nanosystems, in contrast, may also be prepared with biodegradable synthetic polymers, and liquid and solid lipids at room temperature. In this review, recent developments in the use of such nanosystems as nanoparticles, nanotubes, nanocomposites, and nanoemulsions, are discussed critically. The use of polymers as the support matrix for nanodispersions to form edible coatings for food preservation is also analyzed, but the central purpose of the article is to describe available information on nanosystems and their use in different food substrates to help formulators in their work.

Physicochemical, total phenols and pectin methylesterase changes on quality maintenance on guava fruit (Psidium guajava L.) coated with candeuba wax solid lipid nanoparticles-xanthan gum

The objective of this work was to evaluate the application of candeuba wax solid lipid nanoparticles (SLN) and xanthan gum (XG) as coatings on guava, and their effect on the fruits physicochemical and nutritional parameters, complementing a previous publication carried out by Zambrano-Zaragoza et al. (2013). The concentrations of SLN were selected according to those reported as the most (65g/L) and least (75g/L) efficient in post-harvest life preservation, and were compared to a coating of XG and untreated control samples. According to results, the submicron-sized systems used in the coatings with a particle size range of 267-344nm, a polydispersity index <0.2, and zeta potential of -22.8 to -30mV remained stable during 8weeks of storage. The best results were from the fruits coated with 65g/L of SLN and stored at 10°C, as they showed the lowest O2 and CO2 respiration rates and, consequently, less weight loss. They also had the best retention of ascorbic acid and total phenol content, with less change in fruit color compared to the control guava and those coated only with XG. These findings indicate that this batch continued their natural maturation process, but at a slower rate than the other samples. The firmness was affected by the activity of the enzyme pectin methylesterase, but results show that the 65g/L coating was efficient in maintaining fruit texture. In contrast, the 75g/L coating produced epoxy in the fruit, causing physiological damage. Finally, the guava coated with XG only had a maturation rate similar to that of the control fruit.

Effect of processing conditions on the production of nixtamalized corn flours by the traditional method

Nowadays, in Mexico and Latin America, calcium content in the diet is a very important issue. This fact is critical since research studies have shown a relationship between consumption of dietary calcium and chronic degenerative diseases. Deficiencies of calcium in Mexican population involve the search for alternative foods that lead to an increase in the daily calcium intake. In this context, the traditional nixtamalization process is a good option for food processing in order to increase calcium content in foodstuffs. This work focused on the development of an effective methodology to establish the relationships among the processing variables in the production of nixtamalized corn flours by the traditional method. A full compound factorial design was used to determine the effect of some independent variables, involved in the nixtamalization, on the response variables such as (a) Ca+2 content in corn flours, (b) particle size distribution (homogeneity), and (c) average energy consumption during grinding.

Evaluation of the lubricating effect of magnesium stearate and glyceryl behenate solid lipid nanoparticles in a direct compression process

ABSTRACT The aim of this study was to develop solid lipid nanoparticles (SLN) and introduce them into a direct compression process to evaluate their lubricant properties. The study consisted of preparing glyceryl behenate SLN (Compritol® 888 ATO) by hot dispersion, and magnesium stearate SLN by a novel nanoprecipitation/ion exchange method. The ejection force was measured for nanosystems and raw materials in a formulation typically used for direct compression. The smallest particle sizes obtained were 456nm for Compritol® 888 ATO and 330nm for magnesium stearate. Results show that the NPs used as lubricants in a direct compression model formulation provided efficient lubrication by maintaining the lubricating properties of the system, thereby decreasing the amount of lubricant used compared to the raw material. The lubricating effect showed an increase of 15–30% for magnesium stearate and Compritol® 888 ATO, compared to the raw material at concentrations above 2%.

Controlled-release biodegradable nanoparticles: From preparation to vaginal applications

Abstract This study aimed to prepare poly (d,l‐lactide‐co‐glycolide) (PLGA) nanoparticles (NPs) with chitosan (CTS) surface modification to be used as a vaginal delivery system for antimycotic drugs. Clotrimazole was encapsulated with entrapment efficiencies of 86.1 and 68.9% into Clotrimazole‐PLGA‐NPs (CLT‐PLGA‐NPs) and PLGA‐NPs with CTS‐modified surface (CLT‐PLGA‐CTS‐NPs), respectively. The later NPs exhibited a larger size and higher positive zeta potential (Z potential) in comparison to unmodified NPs. In vitro release kinetic studies indicated that Clotrimazole was released in percentages of > 98% from both nanoparticulate systems after 18 days. Antifungal activity and mucoadhesive properties of NPs were enhanced when CTS was added onto the surface. In summary, these results suggested that Clotrimazole loaded into PLGA‐CTS‐NPs has great potential for vaginal applications in treating vaginal infections generated by Candida albicans. Graphical abstract Figure. No caption available.

Effects of extrusion process in snacks of oats–nixtamalized corn pericarp mixtures on dietary fiber content and functional properties

The aim this work was to establish the best conditions to increase the soluble dietary fiber (SDF), evaluate the effect of extrusion on the SDF, and insoluble dietary fiber (IDF), in a snack obtained by extrusion, that serve as a source of calcium and DF, using mixtures of oat–corn pericarp. The corn pericarp was obtained from byproduct of nixtamalization process which contains water, calcium hydroxide, soluble solids, and pericarp. The studied parameters were temperature (120–140°C), moisture (200–400 g/kg), and corn pericarp (200–400 g/kg); the responses were expansion ratio, SDF, IDF, and water absorption index (WAI). The R 2 were > 0.85 for all factors. The best conditions were temperature (133°C), moisture (230 g/kg), and corn pericarp (300 g/kg), with responses of 93.1 g/kg increase in SDF, 60 g/kg decrease of IDF, expansion of 1.26, WAI of 4.12 g sediment/g dry solid, and calcium content 4350 mg/kg.

Preparation of nanodispersions by solvent displacement using the Venturi tube

ABSTRACT The Venturi tube (VT) is an apparatus that produces turbulence which is taken advantage of to produce nanoparticles (NP) by solvent displacement. The objective of this study was to evaluate the potential of this device for preparing NP of poly‐&egr;‐caprolactone. Response Surface Methodology was used to determine the effect of the operating conditions and optimization. The NP produced by VT were characterized by Dynamic Light‐Scattering to determine their particle size distribution (PS) and polydispersity index (PDI). Results showed that the Reynolds number (Re) has a strong effect on both PS and process yield (PY).The turbulence regime is key to the efficient formation of NP. The optimal conditions for obtaining NP were a polymer concentration of 1.6w/v, a recirculation rate of 4.8L/min, and a stabilizer concentration of 1.1w/v. The predicted response of the PY was 99.7%, with a PS of 333nm, and a PDI of 0.2. Maintaining the same preparation conditions will make it possible to obtain NP using other polymers with similar properties. Our results show that VT is a reproducible and versatile method for manufacturing NP, and so may be a feasible method for industrial‐scale nanoprecipitation production.

Approaches in Polymeric Nanoparticles for Vaginal Drug Delivery: A Review of the State of the Art

The vagina is a region of administration with a high contact surface to obtain local or systemic effects. This anatomical area represents special interest for government health systems for different sexually transmitted infections. However, the chemical changes of the vagina, as well as its abundant mucus in continuous exchange, act as a barrier and a challenge for the development of new drugs. For these purposes, the development of new pharmaceutical forms based on nanoparticles has been shown to offer various advantages, such as bioadhesion, easy penetration of the mucosa, and controlled release, in addition to decreasing the adverse effects of conventional pharmaceutical forms. In order to obtain nanoparticles for vaginal administration, the use of polymers of natural and synthetic origin including biodegradable and non-biodegradable systems have gained great interest both in nanospheres and in nanocapsules. The main aim of this review is to provide an overview of the development of nanotechnology for vaginal drug release, analyzing the different compositions of polymeric nanoparticles, and emphasizing new trends in each of the sections presented. At the end of this review, a section analyzes the properties of the vehicles employed for the administration of nanoparticles and discusses how to take advantage of the properties that they offer. This review aims to be a reference guide for new formulators interested in the vaginal route.

Cuantificación de Cobre en Polifenoloxidasa de Frutas Tropicales por Espectrofotometría de Absorción Atómica

Resumen Este estudio cuantifica el contenido de cobre en aguacate y su pH en ciruela, fresa, kiwi, mamey, mango, manzana, pera y platano. Tambien cobre en la enzima polifenoloxidasa y velocidad de obscurecimiento. El cobre se determino mediante espectrofotometria de absorcion atomica en muestras digeridas por via humeda. El aguacate tuvo mas cobre en enzimas (0.059 mg) con mayor velocidad de obscurecimiento (0.751 s -1 ); la fresa tuvo la menor cantidad de cobre (0.016 mg) y la menor velocidad de reaccion (0.115 s -1 ). Las frutas con pH mas acido tuvieron contenido medio de cobre en la enzima y el menor obscurecimiento. La pera y el platano tuvieron velocidad de reaccion (0.3) y pH similares pero contenidos diferentes de cobre. Los resultados permiten establecer una correlacion directa entre el contenido de cobre en enzimas y la velocidad obscurecimiento. Palabras clave: absorcion atomica, cobre, frutas, polifenoloxidasa, velocidad de obscurecimiento Copper Quantification on Tropical Fruits by Atomic Absorption Spectrophotometry